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Sample records for fixed inlet rate

  1. The Deceptive Resilience of Fixed Exchange Rates

    Mushin, Jerry

    2004-01-01

    This paper is an examination of the experience of exchange-rate systems since 1978. Despite the accelerating trend in favour of floating exchange rates, a substantial minority of IMF members have continued to fix the value of their currencies. The recent incidence of each of the principal types of exchange-rate peg is described.

  2. Management strategy 3: fixed rate fertilizer applications

    Previous chapters outlined management strategies for pond fertilization that take into account specific individual pond nutrient needs. Those methods would most likely be more ecologically efficient than a pre-determined fixed-rate nutrient addition strategy. However, the vast majority of available ...

  3. Numerical Analysis of Inlet Gas-Mixture Flow Rate Effects on Carbon Nanotube Growth Rate

    B. Zahed

    2013-01-01

    Full Text Available The growth rate and uniformity of Carbon Nano Tubes (CNTs based on Chemical Vapor Deposition (CVD technique is investigated by using a numerical model. In this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal CVD reactor at atmospheric pressure. Based on the gas phase and surface reactions, released carbon atoms are grown as CNTs on the iron catalysts at the reactor hot walls. The effect of inlet gas-mixture flow rate, on CNTs growth rate and its uniformity is discussed. In addition the velocity and temperature profile and also species concentrations throughout the reactor are presented.

  4. 12 CFR 619.9170 - Fixed interest rate.

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest rate. 619.9170 Section 619.9170 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9170 Fixed interest rate. The rate of interest specified in the note or loan document which will prevail as the maximum...

  5. State estimation for networked control systems using fixed data rates

    Liu, Qing-Quan; Jin, Fang

    2017-07-01

    This paper investigates state estimation for linear time-invariant systems where sensors and controllers are geographically separated and connected via a bandwidth-limited and errorless communication channel with the fixed data rate. All plant states are quantised, coded and converted together into a codeword in our quantisation and coding scheme. We present necessary and sufficient conditions on the fixed data rate for observability of such systems, and further develop the data-rate theorem. It is shown in our results that there exists a quantisation and coding scheme to ensure observability of the system if the fixed data rate is larger than the lower bound given, which is less conservative than the one in the literature. Furthermore, we also examine the role that the disturbances have on the state estimation problem in the case with data-rate limitations. Illustrative examples are given to demonstrate the effectiveness of the proposed method.

  6. Numerical simulation of hypersonic inlet flows with equilibrium or finite rate chemistry

    Yu, Sheng-Tao; Hsieh, Kwang-Chung; Shuen, Jian-Shun; Mcbride, Bonnie J.

    1988-01-01

    An efficient numerical program incorporated with comprehensive high temperature gas property models has been developed to simulate hypersonic inlet flows. The computer program employs an implicit lower-upper time marching scheme to solve the two-dimensional Navier-Stokes equations with variable thermodynamic and transport properties. Both finite-rate and local-equilibrium approaches are adopted in the chemical reaction model for dissociation and ionization of the inlet air. In the finite rate approach, eleven species equations coupled with fluid dynamic equations are solved simultaneously. In the local-equilibrium approach, instead of solving species equations, an efficient chemical equilibrium package has been developed and incorporated into the flow code to obtain chemical compositions directly. Gas properties for the reaction products species are calculated by methods of statistical mechanics and fit to a polynomial form for C(p). In the present study, since the chemical reaction time is comparable to the flow residence time, the local-equilibrium model underpredicts the temperature in the shock layer. Significant differences of predicted chemical compositions in shock layer between finite rate and local-equilibrium approaches have been observed.

  7. Design of movable fixed area γ dose rate monitor

    Li Dongyu; Cheng Wen; Li Jikai; Huang Hong; Shen Qiming; Zhang Qiang; Liu Zhengshan

    2005-10-01

    Movable fixed area γ dose rate monitor has not only the characteristics of fixed area γ dose rate monitor, but that of portable meter as well. Its main function is to monitor the areas where dose rate would change without orderliness to prevent unplanned radiation exposure accidents from happening. The design way of the monitor, the main indicators description, the working principle and the comprising of software and hardware are briefly introduced. The monitor has the characteristics of simple installation, easy maintenance, little power consumption, wide range, notability of visual and audible alarm and so on. Its design and technique have novelty and advancement. (authors)

  8. Fixed-Rate Compressed Floating-Point Arrays.

    Lindstrom, Peter

    2014-12-01

    Current compression schemes for floating-point data commonly take fixed-precision values and compress them to a variable-length bit stream, complicating memory management and random access. We present a fixed-rate, near-lossless compression scheme that maps small blocks of 4(d) values in d dimensions to a fixed, user-specified number of bits per block, thereby allowing read and write random access to compressed floating-point data at block granularity. Our approach is inspired by fixed-rate texture compression methods widely adopted in graphics hardware, but has been tailored to the high dynamic range and precision demands of scientific applications. Our compressor is based on a new, lifted, orthogonal block transform and embedded coding, allowing each per-block bit stream to be truncated at any point if desired, thus facilitating bit rate selection using a single compression scheme. To avoid compression or decompression upon every data access, we employ a software write-back cache of uncompressed blocks. Our compressor has been designed with computational simplicity and speed in mind to allow for the possibility of a hardware implementation, and uses only a small number of fixed-point arithmetic operations per compressed value. We demonstrate the viability and benefits of lossy compression in several applications, including visualization, quantitative data analysis, and numerical simulation.

  9. Effect of flow rate distribution at the inlet on hydrodynamic mixing in narrow rectangular multi-channel

    Xu Jianjun; Chen Bingde; Wang Xiaojun

    2008-01-01

    Flow and heat transfer in the narrow rectangular multi-channel is widely en- countered in the engineering application, hydrodynamic mixing in the narrow rectangular multi-channel is one of the important concerns. With the help of the Computational Fluid Dynamics code CFX, the effect of flow rate distribution of the main channel at the inlet on hydrodynamic mixing in the narrow rectangular multi-channel is numerical simulated. The results show that the flow rate distributions at the inlet have a great effect on hydrodynamics mixing in multi-channel, the flow rate in the main channel doesn't change with increasing the axial mixing section when the average flow rate at the inlet is set. Hydrodynamic mixing will arise in the mixing section when the different ratio of the flow rate distribution at the inlet is set, and hydrodynamic mixing increases with the difference of the flow rate distribution at the inlet increase. The trend of the flow rate distribution of the main channel is consistent during the whole axial mixing section, and hydrodynamic mixing in former 4 mixing section is obvious. (authors)

  10. Optimal bank portfolio choice under fixed-rate deposit insurance

    Anlong Li

    1991-01-01

    An analysis of the investment decisions of a bank whose deposits are fully insured under fixed-rate insurance, showing how banks dynamically adjust their investment portfolios in response to market information and how this flexibility affects both investment decisions and the fair cost of deposit insurance.

  11. Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate

    Kamman, J. H.; Hall, C. L.

    1975-01-01

    Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

  12. 31 CFR 359.10 - What is the fixed rate of return?

    2010-07-01

    .... The composite rate is composed of both the fixed rate and a semiannual inflation rate, which could... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What is the fixed rate of return? 359... BONDS, SERIES I General Information § 359.10 What is the fixed rate of return? The Secretary, or the...

  13. Bretton Woods Fixed Exchange Rate System versus Floating Exchange Rate System

    Geza, Paula; Giurca Vasilescu, Laura

    2011-01-01

    One of the most important issues of monetary policy is to find out whether the state should intervene among the exchange rates, taking into account the fact that changes in the exchange rates represent a significant transmission channel of the effects generated by the monetary policy. Taking into consideration the failure of fixed exchange rate regimes and the recent improvement of financial markets, the return in the near future to such a regime – as for example the Bretton Woods system –...

  14. Numerical and experimental investigation of the bell-mouth inlet design of a centrifugal fan for higher internal flow rate

    Kim, Sang Hyeon; Heo, Seung; Cheong, Cheolung; Kim, Tae Hoon

    2013-01-01

    The energy efficiency of a household refrigerator is one of the most critical characteristics considered by manufacturers and consumers. Numerous studies in various fields have been conducted to increase energy efficiency. One of the most efficient methods to reduce the energy consumption of a refrigerator is by improving the performance of fans inside the refrigerator. A number of studies reported various ways to enhance fan performance. However, the majority of these studies focused solely on the fan and did not consider the working environment of the fan, such as the inlet and outlet flow characteristics. The expected performance of fans developed without consideration of these characteristics cannot be determined because complex inlet and outlet flow passage could adversely affect performance. This study investigates the effects of the design of the bell-mouth inlet on the performance of a centrifugal fan in a household refrigerator. In preliminary numerical studies, significant flow loss is identified through the bell-mouth inlet in the target fan system. Several design factors such as tip clearance, inner fence, motor-box struts, and guide vane are proposed to resolve these flow losses. The effects of these factors on fan performance are investigated using computational fluid dynamics techniques to solve incompressible Reynolds-averaged Navier-Stokes equations for predicting the circulating flow of the fan. Experiments are then performed to validate the numerical predictions. Results indicate that four design factors positively affect fan performance in terms of flow rate. The guide vane is the most effective design factor to consider for improving fan performance. Further studies are conducted to investigate the detailed effects of the guide vane by varying its install angle, install location, height, and length. These studies determine the optimum design of the guide vane to achieve the highest performance of the fan and the related flow characteristics

  15. Numerical and experimental investigation of the bell-mouth inlet design of a centrifugal fan for higher internal flow rate

    Kim, Sang Hyeon; Heo, Seung; Cheong, Cheolung [Pusan National University, Busan (Korea, Republic of); Kim, Tae Hoon [Refrigeration Division, Changwon (Korea, Republic of)

    2013-08-15

    The energy efficiency of a household refrigerator is one of the most critical characteristics considered by manufacturers and consumers. Numerous studies in various fields have been conducted to increase energy efficiency. One of the most efficient methods to reduce the energy consumption of a refrigerator is by improving the performance of fans inside the refrigerator. A number of studies reported various ways to enhance fan performance. However, the majority of these studies focused solely on the fan and did not consider the working environment of the fan, such as the inlet and outlet flow characteristics. The expected performance of fans developed without consideration of these characteristics cannot be determined because complex inlet and outlet flow passage could adversely affect performance. This study investigates the effects of the design of the bell-mouth inlet on the performance of a centrifugal fan in a household refrigerator. In preliminary numerical studies, significant flow loss is identified through the bell-mouth inlet in the target fan system. Several design factors such as tip clearance, inner fence, motor-box struts, and guide vane are proposed to resolve these flow losses. The effects of these factors on fan performance are investigated using computational fluid dynamics techniques to solve incompressible Reynolds-averaged Navier-Stokes equations for predicting the circulating flow of the fan. Experiments are then performed to validate the numerical predictions. Results indicate that four design factors positively affect fan performance in terms of flow rate. The guide vane is the most effective design factor to consider for improving fan performance. Further studies are conducted to investigate the detailed effects of the guide vane by varying its install angle, install location, height, and length. These studies determine the optimum design of the guide vane to achieve the highest performance of the fan and the related flow characteristics

  16. Research for the influence on PRHR HX performance with different inlet temperature and flow rate

    Jia Bin; Jing Jianping; An Jieru; Bi Jinsheng; Li Yuanshan; Zhuang Shaoxin

    2014-01-01

    To study the residual heat removal capacity of PRHR HX, numerical simulation is demonstrated using FLUENT. Meanwhile to research the trends of PRHR HX residual heat removal capacity, different operating modes have been simulated with parameters deviated from design value. Finally it's found that when the coolant inlet temperature is higher than design valve the residual heat removal capacity is better and the higher the temperature is the lower the coolant outlet temperature can be obtained. And meanwhile the faster the coolant flows the better the residual heat in the core can be removed. (authors)

  17. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    Mothilal, T.; Pitchandi, K.

    2015-01-01

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%

  18. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    Mothilal, T. [T. J. S. Engineering College, Gummidipoond (India); Pitchandi, K. [Sri Venkateswara College of Engineering, Sriperumbudur (India)

    2015-10-15

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%.

  19. Stochastic Discount Factor Approach to International Risk-Sharing: Evidence from Fixed Exchange Rate Episodes

    Hadzi-Vaskov, M.; Kool, C.J.M.

    2007-01-01

    This paper presents evidence of the stochastic discount factor approach to international risk-sharing applied to fixed exchange rate regimes. We calculate risk-sharing indices for two episodes of fixed or very rigid exchange rates: the Eurozone before and after the introduction of the Euro, and

  20. Effects of reaction temperature and inlet oxidizing gas flow rate on IG-110 graphite oxidation used in HTR-PM

    Sun Ximing; Dong Yujie; Zhou Yangping; Shi Lei; Sun Yuliang; Zhang Zuoyi; Li Zhengcao

    2017-01-01

    The oxidation behavior of a selected nuclear graphite (IG-110) used in Pebble-bed Module High Temperature gas-cooled Reactor was investigated under the condition of air ingress accident. The oblate rectangular specimen was oxidized by oxidant gas with oxygen mole fraction of 20% and flow rates of 125–500 ml/min at temperature of 400–1200°C. Experiment results indicate that the oxidation behavior can also be classified into three regimes according to temperature. The regime I at 400–550°C has lower apparent activation energies of 75.57–138.59 kJ/mol when the gas flow rate is 125–500 ml/min. In the regime II at 600–900°C, the oxidation rate restricted by the oxygen supply to graphite is almost stable with the increase of temperature. In the regime III above 900°C, the oxidation rate increases obviously with the increase of temperature.With the increase of inlet gas flow from 125 to 500 ml/min, the apparent activation energy in regime I is increased and the stableness of oxidation rate in regime II is reduced. (author)

  1. Numerical and experimental investigation on effects of inlet humidity and fuel flow rate and oxidant on the performance on polymer fuel cell

    Takalloo, Pourya Karimi; Nia, Ehsan Shabahang; Ghazikhani, Mohsen

    2016-01-01

    Highlights: • The impact of alteration in humidification on performance of fuel cell. • The impact of variation of temperature on performance of fuel cell. • The effects of using pure oxygen on the polarity curve are studied. • Fuel cell has been investigated both experimentally and numerically. - Abstract: Considering the importance of water management in a fuel cell and in order to increase the rate of the electro-chemical process in fuel cells with polymer membrane, it is required to optimize the humidity and inlet flow rates on anode and cathode sides. In this study, the impact of alteration in humidification and inlet flow rates on performance improvements for polymer membrane fuel cells is investigated both experimentally and numerically. To obtain the objective, employing the results from experiments and simulations, polarity curve and power density are produced and further used to conduct the desired investigations. In addition, through the conducted simulations the effects of using pure oxygen in the cathode side and inlet gas temperatures on the polarity curve is studied. The results demonstrate that an increase in humidity of the inlet gases will lead to performance amelioration in the cell, due to reduction in ionic resistance at the membrane. Furthermore, with the aforementioned increment; molar fractions of hydrogen and oxygen are decreased through the channel which results in produced water increment. Amplification in inlet flow rates to a certain level will improve the penetration possibility for gaseous forms leading to betterment of the cell performance in this specified range. Performance improvements with inlet gases temperature increment conclude other results of this study.

  2. 13 CFR 120.213 - What fixed interest rates may a Lender charge?

    2010-01-01

    ... Lender charge? 120.213 Section 120.213 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... have a reasonable fixed interest rate. SBA periodically publishes the maximum allowable rate in the... government determines the interest rate on direct loans. SBA publishes the rate periodically in the Federal...

  3. Changes in Blood Pressure and Heart Rate during Fixed-Interval Responding in Squirrel Monkeys

    DeWeese, Jo

    2009-01-01

    Episodic and sustained increases in heart rate and mean arterial blood pressure can occur with recurring patterns of schedule-controlled behavior. Most previous studies were conducted under fixed-ratio schedules, which maintained a consistent high rate of responding that alternated with periods of no responding during times when the schedule was…

  4. The fixed target experiment for studies of baryonic matter at the Nuclotron (BM rate at N)

    Kapishin, Mikhail [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation)

    2016-08-15

    BM rate at N (Baryonic Matter at Nuclotron) is the first experiment to be realized at the accelerator complex of NICA-Nuclotron. The aim of the BM rate at N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. The BM rate at N setup, results of Monte Carlo simulations and the BM rate at N experimental program are presented. (orig.)

  5. Coastal Inlet Model Facility

    Federal Laboratory Consortium — The Coastal Inlet Model Facility, as part of the Coastal Inlets Research Program (CIRP), is an idealized inlet dedicated to the study of coastal inlets and equipped...

  6. 48 CFR 3452.216-71 - Negotiated overhead rates-fixed.

    2010-10-01

    ... acceptability of cost allocation methods shall be determined in accordance with part 31 of the Federal... different period, for which the rates apply, and (4) the specific items treated as direct costs or any changes in the items previously agreed to be direct costs. (e) Pending establishment of fixed overhead...

  7. Choice of exchange rate regimes for African countries: Fixed or Flexible Exchange rate regimes?

    Simwaka, Kisu

    2010-01-01

    The choice of an appropriate exchange rate regime has been a subject of ongoing debate in international economics. The majority of African countries are small open economies and thus where the choice of the exchange rate regime is an important policy issue. Aside from factors such as interest rates and inflation, the exchange rate is one of the most important determinants of a country’s relative level of economic health. For this reason, exchange rates are among the most watched analyzed and ...

  8. Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

    Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Davidson, Carolyn [National Renewable Energy Lab. (NREL), Golden, CO (United States); McLaren, Joyce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset, on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.

  9. Adjustment to Monetary Policy and Devaluation Under Two-Tier and Fixed Exchange Rate Regimes

    Joshua Aizenman

    1983-01-01

    The purpose of this paper is to determine whether a two-tier exchange rate regime is more effective than a fixed rate regime in increasing acountry's ability to pursue an independent monetary policy in the short run.The analysis compares adjustment to a monetary policy and to a devaluation in the two exchange rate regimes in a portfolio model under imperfect asset substitutability. It is shown that the two policies have in the short run larger effects on interest rates under a two-tier regime...

  10. Zero-Outage Cellular Downlink with Fixed-Rate D2D Underlay

    Kiilerich Pratas, Nuno; Popovski, Petar

    2015-01-01

    . D2D connections can be instrumental in localized aggregation of uplink M2M traffic to a more capable cellular device, before being finally delivered to the Base Station (BS). In this paper we show that a fixed M2M rate is an enabler of efficient Machine-Type D2D underlay operation taking place......, but not the interfering channels from the MTDs to U, we prove that there is a positive downlink rate that can always be decoded by U, leading to zero-outage of the downlink signal. This is a rather surprising consequence of the features of the multiple access channel and the fixed rate RM. We also consider the case...... of a simpler, single-user decoder at U with successive interference cancellation. However, with single-user decoder, a positive zero-outage rate exists only when NM = 1 and is zero when NM > 1. This implies that joint decoding is instrumental in enabling fixed-rate underlay operation....

  11. Determination of the enzyme reaction rate in a differential fixed-bed reactor: a case study

    Baruque Filho E.A.

    2001-01-01

    Full Text Available The reaction rate of starch hydrolysis catalyzed by a glucoamylase covalently bound to chitin particles was measured in a Differential Fixed-Bed Reactor (DFBR. Under selected test conditions the initial reaction rate may represent biocatalyst activity. Some aspects which influence measurement of the initial reaction rate of an immobilized enzyme were studied: the amount of desorbed enzyme and its hydrolytic activity, the extent of pore blockage of the biocatalyst caused by substrate solution impurities and the internal and external diffusional mass transfer effects. The results showed that the enzyme glucoamylase was firmly bound to the support, as indicated by the very low amount of desorbed protein found in the recirculating liquid. Although this protein was very active, its contribution to the overall reaction rate was negligible. It was observed that the biocatalyst pores were susceptible to being blocked by the impurities of the starch solution. This latter effect was accumulative, increasing with the number of sequential experiments carried out. When the substrate solution was filtered before use, very reliable determinations of immobilized enzyme reaction rates could be performed in the DFBR. External and internal diffusional resistences usually play a significant role in fixed-bed reactors. However, for the experimental system studied, internal mass transfer effects were not significant, and it was possible to select an operational condition (recirculation flow rate value that minimized the external diffusional limitations.

  12. Siltation rate and main anthropic impacts on sedimentation of the São Luís tidal inlet - State of Maranhão, Brazil

    James Werllen de Jesus Azevedo

    2016-03-01

    Full Text Available Abstract In recent decades, intense human intervention in the coastal zone has given rise to severe siltation and erosion problems. This scenario is located the São Luís tidal inlet, formed by the mouths of the Anil and Bacanga rivers which due to various kinds of interference have been changing their sediment transport and deposition processes. With these changes in mind, this study sought to evaluate the evolution of the siltation and sedimentation rates in this area, as well as the main anthropogenic influences associated with this process. The methodology consisted in verifying the morphological evolution on the basis of the scanning and vectorization of nautical charts of 1947 and 1966, bathymetric surveys conducted in 2006, and aerial photos dating from 2011. The results show a silting up process coincident with interventions that occurred in the Anil and Bacanga river basins, with a volume of silt estimated at 8.5x106 m3, over the period from 1944 to 2011 (64 years, at a rate of 1.6 cm.yr-1. These processes are associated mainly with the construction of the Bacanga dam and land reclamation projects undertaken for the purpose of providing new areas for urban expansion. The evaluation of the results showed intense and advanced silting up of the São Luís tidal inlet, at rates proportionally greater than those of other estuaries, calling for corrective actions and the implementation of coastal management policies for this area.

  13. Investigating the effect of gas flow rate, inlet ozone concentration and relative humidity on the efficacy of catalytic ozonation process in the removal of xylene from waste airstream

    H.R. MokaramI

    2010-10-01

    Full Text Available Background and aimsThe catalytic ozonation is an efficient process for the degradation of volatile organic compounds from contaminated air stream. This study was aimed at investigating the efficacy of catalytic ozonation process in removal of xylene from the polluted air stream andthe influence of retention time (gas flow rate, inlet ozone dose and relative humidity on this performanceMethodsthe catalytic ozonation of xylene was conducted using a bench scale set-up consisted of a syringe pump,an air pump, an ozone generator, and a glass reactor packed with activated carbon. Several experimental run was defined to investigate the influence of the selectedoperational variables.ResultsThe results indicated that the efficiency of catalytic ozonation was greater than that of single adsorption in removal of xylene under similar inlet concentration and relative humidity. We found a significant catalytic effect for activated carbon when used in combination with ozonation process, leading to improvement of xylene removal percentage. In addition, the elimination capacity of the system improved with the increase of inlet ozone dose as well as gas flow rate. The relative humidity showed a positive effect of the xylene removal at the range of 5 to 50%, while the higher humidity (more than 50% resulted in reduction of the performance.ConclusionThe findings of the present work revealed that the catalytic ozonation process can be an efficient technique for treating the air streams containing industrial concentrations of xylene. Furthermore, there is a practical potential to retrofit the present adsorption systems intothe catalytic ozonation simply by coupling them with the ozonation system. the catalytic ozonation of xylene was conducted using a bench scale set-up consisted of a syringe pump,an air pump, an ozone generator, and a glass reactor packed with activated carbon. Several experimental run was defined to investigate the influence of the selected

  14. Construction of Fixed Rate Non-Binary WOM Codes Based on Integer Programming

    Fujino, Yoju; Wadayama, Tadashi

    In this paper, we propose a construction of non-binary WOM (Write-Once-Memory) codes for WOM storages such as flash memories. The WOM codes discussed in this paper are fixed rate WOM codes where messages in a fixed alphabet of size $M$ can be sequentially written in the WOM storage at least $t^*$-times. In this paper, a WOM storage is modeled by a state transition graph. The proposed construction has the following two features. First, it includes a systematic method to determine the encoding regions in the state transition graph. Second, the proposed construction includes a labeling method for states by using integer programming. Several novel WOM codes for $q$ level flash memories with 2 cells are constructed by the proposed construction. They achieve the worst numbers of writes $t^*$ that meet the known upper bound in many cases. In addition, we constructed fixed rate non-binary WOM codes with the capability to reduce ICI (inter cell interference) of flash cells. One of the advantages of the proposed construction is its flexibility. It can be applied to various storage devices, to various dimensions (i.e, number of cells), and various kind of additional constraints.

  15. Does grandchild care influence grandparents' self-rated health? Evidence from a fixed effects approach.

    Ates, Merih

    2017-10-01

    The present study aims to identify, whether and how supplementary grandchild care is causally related to grandparents' self-rated health (SRH). Based on longitudinal data drawn from the German Aging Survey (DEAS; 2008-2014), I compare the results of pooled OLS, pooled OLS with lagged dependant variables (POLS-LD), random and fixed effects (RE, FE) panel regression. The results show that there is a positive but small association between supplementary grandchild care and SRH in POLS, POLS-LD, and RE models. However, the fixed effects model shows that the intrapersonal change in grandchild care does not cause a change in grandparents' SRH. The FE findings indicate that supplementary grandchild care in Germany does not have a causal impact on grandparents' SRH, suggesting that models with between-variation components overestimate the influence of grandchild care on grandparents' health because they do not control for unobserved (time-constant) heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Buyer-vendor coordination for fixed lifetime product with quantity discount under finite production rate

    Zhang, Qinghong; Luo, Jianwen; Duan, Yongrui

    2016-03-01

    Buyer-vendor coordination has been widely addressed; however, the fixed lifetime of the product is seldom considered. In this paper, we study the coordination of an integrated production-inventory system with quantity discount for a fixed lifetime product under finite production rate and deterministic demand. We first derive the buyer's ordering policy and the vendor's production batch size in decentralised and centralised systems. We then compare the two systems and show the non-coordination of the ordering policies and the production batch sizes. To improve the supply chain efficiency, we propose quantity discount contract and prove that the contract can coordinate the buyer-vendor supply chain. Finally, we present analytically tractable solutions and give a numerical example to illustrate the benefits of the proposed quantity discount strategy.

  17. Limitations to very high rate wire chambers in fixed target geometries

    Spiegel, L.

    1989-11-01

    The task is to explore physical limitations to the operation of wire chambers in fixed target geometries at an interaction rate of 52 MHz (chosen as it corresponds to the FNAL accelerator rf rate.) That is, to see if there are physical limitations to the operation of gaseous wire chambers at such a high operating rate. A primary proton beam energy of 800 GeV has been assumed although modest increases in the primary energy should not affect the basic conclusion as secondary multiplicity increases logarithmically with center-of-momentum energy. By sustaining a 52 MHz interaction rate it is meant that results from a given interaction are electronically isolated from preceding and subsequent rf buckets, good wire plane efficiency is maintained throughout the active region of the chamber, and the chamber operates in a stable manner throughout the course of a typical fixed target run -- six months to a full year. Other working assumptions include the understanding that chamber electronics -- amplifiers, discriminators, delay elements, encoders -- will not suffer degradation at 52 MHz and that the intensely populated beam regions have been somehow excluded from the chambers. 7 refs., 2 figs

  18. Inlet Geomorphology Evolution

    2015-04-01

    APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Inlet Geomorphology Evolution 5a. CONTRACT NUMBER 5b...Std Z39-18 Coastal Inlets Research Program Inlet Geomorphology Evolution The Inlet Geomorphology Evolution work unit of the CIRP evaluates

  19. The Credit-Risk Decision Mechanism on Fixed Loan Interest Rate with Imperfect Information

    2001-01-01

    In this paper, decision mechanism of credit-risk for banks is studied when the loan interest rate is fixed with asymmetry information in credit market. We give out the designs of rationing and non-rationing on credit risky decision mechanism when collateral value provided by an entrepreneur is not less than the minimum demands of the bank. It shows that under the action of the mechanism, banks could efficiently identify the risk size of the project. Finally, the condition of the project investigation of bank is given over again.

  20. Higher order constraints on the Higgs production rate from fixed-target DIS data

    Alekhin, S.; Bluemlein, J.; Moch, S.

    2011-01-01

    The constraints of fixed-target DIS data in fits of parton distributions including QCD corrections to next-to-next-to leading order are studied. We point out a potential problem in the analysis of the NMC data which can lead to inconsistencies in the extracted value for α s (M Z ) and the gluon distribution at higher orders in QCD. The implications for predictions of rates for Standard Model Higgs boson production at hadron colliders are investigated. We conclude that the current range of excluded Higgs boson masses at the Tevatron appears to be much too large. (orig.)

  1. THE CURRENT ACCOUNT DEFICIT AND THE FIXED EXCHANGE RATE. ADJUSTING MECHANISMS AND MODELS.

    HATEGAN D.B. Anca

    2010-07-01

    Full Text Available The main purpose of the paper is to explain what measures can be taken in order to fix the trade deficit, and the pressure that is upon a country by imposing such measures. The international and the national supply and demand conditions change rapidly, and if a country doesn’t succeed in keeping a tight control over its deficit, a lot of factors will affect its wellbeing. In order to reduce the external trade deficit, the government needs to resort to several techniques. The desired result is to have a balanced current account, and therefore, the government is free to use measures such as fixing its exchange rate, reducing government spending etc. We have shown that all these measures will have a certain impact upon an economy, by allowing its exports to thrive and eliminate the danger from excessive imports, or vice-versa. The main conclusion our paper is that government intervention is allowed in order to maintain the balance of the current account.

  2. The macroeconomic effects of oil shocks under fixed and flexible exchange rates - a comparison

    Harvie, C.

    1993-01-01

    The objective of this paper is to explore further, from a primarily theoretical perspective, the macroeconomic implications arising for an oil-producing economy operating with either a fixed or flexible exchange rate system - to explore, in particular, which of these two extreme systems best offers insulatory properties, in the sense of reducing the volatility of adjustment of key macroeconomic variables arising primarily from oil-related shocks. The issue is explored by analyzing a theoretical framework, which emphasizes the long-run nature of the adjustment process. Such an emphasis is particularly pertinent in models which assume that economic agents possess rational expectations, where long-run equilibrium will have a major bearing upon the short-run adjustment process itself. However, due to the complexity of the model developed here, it is not possible to derive analytical unambiguous results, hence emphasis is placed upon deriving results through numerical simulation. The results derived enable an identification to be made of the importance, for policy purposes, of implementing an appropriate exchange rate system for oil producing and exporting economics with the characteristics emphasised in this paper. (3 figures). (Author)

  3. Conception rates to fixed-time artificial insemination of two oestrus synchronisation programmes in dairy heifers.

    Sahu, S K; Parkinson, T J; Laven, R A

    2015-05-01

    To evaluate the conception rate to fixed-time artificial insemination (FTAI) of two oestrus synchronisation programmes in dairy heifers on eight farms over 2 years. The study was conducted in 2008 and 2010 on eight farms near Palmerston North, New Zealand. Nulliparous Friesian and Friesian×Jersey heifers (13-15 months of age) were randomly allocated to one of two oestrus synchronisation programmes. Group 1 (GPG+P4; n=330), received gonadotrophin-releasing hormone (GnRH) I/M on Day 0, a progesterone (P4)-releasing intravaginal device from Days 0-7, prostaglandin F2α (PGF) I/M on Day 7 and a second dose of GnRH at the time of FTAI on Day 9. The second group (P4+PGF; n=343) received a P4-releasing intravaginal device from Days 0-7, PGF on Day 6 and FTAI on Day 9. Pregnancy was diagnosed from Days 42-52 by transrectal ultrasonography. The overall conception rate was 52.4% and 54.8% for the GPG+P4 and P4+PGF groups, respectively. The odds of conception for the two treatments were not different (OR=0.90; 95% CI=0.67-1.23), nor was there any difference between groups in different years (p=0.58). Farm affected conception rate (p=0.002), but there was no interaction with treatment (p=0.92) . This study has shown that an alternative synchronisation programme can produce similar results in terms of conception rate to the GPG+P4 treatment, currently commonly used in heifers. More research is required to establish whether other modifications to the GPG+P4 programme can produce similar results at lower costs, and to identify and quantify farm factors which affect the economic benefit of heifer synchronisation. This study indicated that synchronising heifers with P4 and PGF resulted in conception rates equivalent to those resulting from a GPG+P4 treatment, but with reduced drug costs. However, because heifers in the GPG+P4 group received the second GnRH injection at the time of AI, they needed only three yardings as opposed to the four required for the heifers treated with P4

  4. Numerical Exploration of Kaldorian Macrodynamics: Hopf-Neimark Bifurcations and Business Cycles with Fixed Exchange Rates

    Toichiro Asada

    2007-01-01

    Full Text Available We explore numerically a three-dimensional discrete-time Kaldorian macrodynamic model in an open economy with fixed exchange rates, focusing on the effects of variation of the model parameters, the speed of adjustment of the goods market α, and the degree of capital mobility β on the stability of equilibrium and on the existence of business cycles. We determine the stability region in the parameter space and find that increase of α destabilizes the equilibrium more quickly than increase of β. We determine the Hopf-Neimark bifurcation curve along which business cycles are generated, and discuss briefly the occurrence of Arnold tongues. Bifurcation and Lyapunov exponent diagrams are computed providing information on the emergence, persistence, and amplitude of the cycles and illustrating the complex dynamics involved. Examples of cycles and other attractors are presented. Finally, we discuss a two-dimensional variation of the model related to a “wealth effect,” called model 2, and show that in this case, α does not destabilize the equilibrium more quickly than β, and that a Hopf-Neimark bifurcation curve does not exist in the parameter space, therefore model 2 does not produce cycles.

  5. Fixed dynamometry is more sensitive than vital capacity or ALS rating scale.

    Andres, Patricia L; Allred, Margaret Peggy; Stephens, Helen E; Proffitt Bunnell, Mary; Siener, Catherine; Macklin, Eric A; Haines, Travis; English, Robert A; Fetterman, Katherine A; Kasarskis, Edward J; Florence, Julaine; Simmons, Zachary; Cudkowicz, Merit E

    2017-10-01

    Improved outcome measures are essential to efficiently screen the growing number of potential amyotrophic lateral sclerosis (ALS) therapies. This longitudinal study of 100 (70 male) participants with ALS compared Accurate Test of Limb Isometric Strength (ATLIS), using a fixed, wireless load cell, with ALS Functional Rating Scale-Revised (ALSFRS-R) and vital capacity (VC). Participants enrolled at 5 U.S. sites. Data were analyzed from 66 participants with complete ATLIS, ALSFRS-R, and VC data over at least 3 visits. Change in ATLIS was less variable both within- and among-person than change in ALSFRS-R or VC. Additionally, participants who had normal ALSFRS-R arm and leg function averaged 12 to 32% below expected strength values measured by ATLIS. ATLIS was more sensitive to change than ALSFRS-R or VC and could decrease sample size requirements by approximately one-third. The ability of ATLIS to detect prefunctional change has potential value in early trials. Muscle Nerve 56: 710-715, 2017. © 2017 Wiley Periodicals, Inc.

  6. INLET STRATIFICATION DEVICE

    2006-01-01

    An inlet stratification device (5) for a circuit circulating a fluid through a tank (1 ) and for providing and maintaining stratification of the fluid in the tank (1 ). The stratification de- vice (5) is arranged vertically in the tank (1) and comprises an inlet pipe (6) being at least partially...... formed of a flexible porous material and having an inlet (19) and outlets formed of the pores of the porous material. The stratification device (5) further comprises at least one outer pipe (7) surrounding the inlet pipe (6) in spaced relationship thereto and being at least partially formed of a porous...

  7. Stress effect on conception rate in Nellore cows submmited to fixed time artificial insemination. Preliminary results

    Fábio Luis Nogueira Natal

    2013-12-01

    Full Text Available In beef cattle, fixed time artificial insemination (FTAI provides a method to inseminate large numbers of females in a specific time, which result in economical gains due, among others, to a more uniform calf crop. However, FTAI requires frequent manipulation of animals in order to inject hormones and for clinical examination. Consequently, animals seemed stressed in less or higher extent at the time of insemination. This can be a problem because it has been demonstrated that application of an acute stress treatment (electric shock, confinement, restraint and rotation twice a day during the follicular phase of the oestrous cycle prevents the pre-ovulatory LH surge. This study aimed to evaluate if FTAI efficiency of Nellore cows is affected by the degree of stress observed at time of AI. Nellore cows (n=92 were treated (Day 0 with a progesterone intravaginal devise (Primer®, Tecnopec, São Paulo, Brazil containing 1 g of progesterone and injected with estradiol benzoate (2mg EB, Estrogin, AUSA, Brazil. Primer was removed on Day 8 (08:00 AM and administered one injection of cloprostenol (125 mcg, Prolise®, Tecnopec, São Paulo, Brazil. Twenty-four hours later, cows received 2 mg EB and insemination (semen from one sire was done on the afternoon (14:00 to 16:00 PM of day 10. At time of FTAI, the stress condition was classified as 1 (low, 2 (moderate or 3 (high according the reactivity of cows to enter in the squeeze chute and apparent nervous behavior. Pregnancy status was evaluated by transrectal ultrasound on day 40 after FTAI. Data were analyzed by Chi-square test. Cows with moderate or high degree of stress had lower conception rate than low stressed cows (P<0.01. These results suggest that cow temperament must be considered in the planning of FTAI programs. Studies are in progress in order to measure hormonal parameters (cortisol and Alpha amylase that better reflects the “fight-or-flight” response to immediate stressors in order to

  8. Conceptual design of a fixed-pitch wind turbine generator system rated at 400 kilowatts

    Pintz, A.; Kasuba, R.; Spring, J.

    1984-01-01

    The design and cost aspects of a fixed pitch, 400 kW Wind Turbine Generator (WTG) concept are presented. Improvements in reliability and cost reductions were achieved with fixed pitch operation and by incorporating recent advances in WTG technology. The specifications for this WTG concept were as follows: (1) A fixed pitch, continuous wooden rotor was to be provided by the Gougeon Bros. Co. (2) An 8 leg hyperboloid tower that showed promise as a low cost structure was to be used. (3) Only commercially available components and parts that could be easily fabricated were to be considered. (4) Design features deemed desirable based on recent NASA research efforts were to be incorporated. Detailed costs and weight estimates were prepared for the second machine and a wind farm of 12 WTG's. The calculated cost of energy for the fixed pitch, twelve unit windfarm is 11.5 cents/kW hr not including the cost of land and access roads. The study shows feasibility of fixed pitch, intermediate power WTG operation.

  9. [Technical complications rates and plaque control of fixed dental prostheses in patients treated for periodontal disease].

    Xie, Yesi; Meng, Huanxin; Han, Jie; Pan, Shaoxia; Zhang, Li; Shi, Dong

    2016-02-01

    To compare the incidence of technical complications of implant-supported fixed dental prostheses in Chinese patients with a history of moderate or severe periodontitis and periodontally healthy patients(PHP) and analyze the effects of interproximal papillae patterns on food impaction and efficacy of plaque control. A total of 103 partially edentulous patients treated with implant-supported fixed dental prostheses between December 2009 and December 2012 for a minimum 1-year follow-up period were recruited from Department of Periodontology, Peking University, School and Hospital of Stomatology. Based on the initial periodontal examination, the participants were divided into three groups: 30 PHP, 36 moderate periodontally compromised patients(mPCP) and 37 severe periodontally compromised patients(sPCP). Implant survival/loss, technical complications, plaque index, papilla index, food impaction and degree of proximal contact tightness of each patient were assessed around the implants at follow-up. According to the implant papilla index, the implants were divided into two groups: the "filling" group with the mesial and distal aspects with papilla index=3 and the "no filling" group with at least one aspect with papilla indextechnical complications were analyzed. Comparisons of the incidence of technical complications were performed between the patients with different periodontal conditions with chi-square or Fisher's exact test. The influences of the interproximal papillae loss on food impaction and efficacy of plaque control were estimated with chi-square and Mann-Whitney U tests. The total implant survival rate was 100%(162/162) for all three groups. Technical complications were as following: veneer fractures(1.9%, 3/162), abutment screw loosening(1.9%, 3/162), prosthetic screw loosening(3.1%, 5/162) and decementation(3.1%, 5/162) in all subjects. No implant/screw fracture was noted. The incidence of technical complications in sPCP, mPCP and PHP did not yield

  10. Effect of selecting a fixed dephosphorylation rate on the estimation of rate constants and rCMRGlu from dynamic [18F] fluorodeoxyglucose/PET data

    Dhawan, V.; Moeller, J.R.; Strother, S.C.; Evans, A.C.; Rottenberg, D.A.

    1989-01-01

    Several publications have discussed the estimation and physiologic significance of regional [ 18 F]fluorodeoxyglucose (FDG) rate constants and metabolic rates. Most of these studies analyzed dynamic data collected over 45-60 min; three rate constants (k1-k3) and blood volume (Vb) were estimated and the regional cerebral metabolic rate for glucose (rCMRGlu) was subsequently derived using the measured blood glucose value and a regionally invariant value of the lumped constant (LC). The dephosphorylation rate constant (k4) was either neglected, or a fixed value was used in the estimation procedure to obtain the remaining parameters. To compare the rate constants obtained by different authors using different values of k4 is impossible without knowledge of the effect of selecting different fixed values of k4 (including zero) on the estimated rate constants and rCMRGlu. Based on our analysis of FDG/PET data from nine normal volunteer subjects, we conclude that inclusion of a fixed value for k4, in spite of a scaling effect on the absolute values of model parameters, has no effect on the coefficient of variation (CV) of within- and between-subject parameter estimates and glucose metabolic rates

  11. Failure Rates of Orthodontic Fixed Lingual Retainers bonded with Two Flowable Light-cured Adhesives: A Comparative Prospective Clinical Trial.

    Talic, Nabeel F

    2016-08-01

    This comparative prospective randomized clinical trial examined the in vivo failure rates of fixed mandibular and maxillary lingual retainers bonded with two light-cured flowable composites over 6 months. Consecutive patients were divided into two groups on a 1:1 basis. Two hundred fixed lingual retainers were included, and their failures were followed for 6 months. One group (n = 50) received retainers bonded with a nano-hybrid composite based on nano-optimized technology (Tetric-N-Flow, Ivoclar Vivadent). Another group (n = 50) received retainers bonded with a low viscosity (LV) composite (Transbond Supreme LV, 3M Unitek). There was no significant difference between the overall failure rates of mandibular retainers bonded with Transbond (8%) and those bonded with Tetric-N-Flow (18%). However, the odds ratio for failure using Tetric-N-flow was 2.52-fold greater than that of Transbond. The failure rate of maxillary retainers bonded with Transbond was higher (14%), but not significantly different, than that of maxillary retainers bonded with Tetric-N-flow (10%). There was no significant difference in the estimated mean survival times of the maxillary and mandibular retainers bonded with the two composites. Both types of composites tested in the current study can be used to bond fixed maxillary and mandibular lingual retainers, with low failure rates.

  12. Inlet Geomorphology Evolution Work Unit

    2015-10-30

    Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...morphologic response. Presently, the primary tool of the Inlet Geomorphology Evolution work unit is the Sediment Mobility Tool (SMT), which allows the user

  13. Inflation Persistence under Semi-Fixed Exchange Rate Regimes:The European Evidence 1974-1998

    Kool, C.J.M.; Lammertsma, A.

    2004-01-01

    In this paper, we empirically investigate the link between exchange rate accommodation and inflation persistence in Europe. We introduce the lagged level of the real exchange rate as an appropriate indicator of exchange rate accommodation. We correspondingly estimate a non-linear autoregressive

  14. The feasibility of a fixed exchange rate regime for new EU-members: evidence from real exchange rates

    Candelon, B.; Kool, C.J.M.; Raabe, K.; van Veen, T.

    2005-01-01

    In this paper, we estimate fundamental bilateral real exchange rates for a group of eight accession countries using a panel-cointegration approach for the period 1993-2003. We document a significant positive link between productivity levels and the corresponding real exchange rate levels. Future

  15. The feasibility of a fixed exchange rate regime for new EU-members : Evidence from real exchange rates

    Candelon, B.; Kool, C.J.M.; Raabe, K.; Veen, van A.P. (Tom)

    2005-01-01

    In this paper, we estimate fundamental bilateral real exchange rates for a group of eight accession countries using a panel-cointegration approach for the period 1993-2003. We document a significant positive link between productivity levels and the corresponding real exchange rate levels. Future

  16. Interest Rate Fluctuation Effect on Commercial Bank's Fixed Fund Deposit in Nigeria

    Okolo Chimaobi Valentine

    2015-01-01

    Commercial banks in Nigeria adopted many strategies to attract fresh deposits including the use of high deposit rate. However, pricing of banking services moved in favor of the banks at the expense of customers, resulting in their seeking other investment alternatives rather than saving their money in the bank. Both deposit and lending rates were greatly influenced by the Central Bank of Nigeria (CBN) decision on interest rate. Therefore, commercial bank effort to attract...

  17. On the problem of non-zero word error rates for fixed-rate error correction codes in continuous variable quantum key distribution

    Johnson, Sarah J; Ong, Lawrence; Shirvanimoghaddam, Mahyar; Lance, Andrew M; Symul, Thomas; Ralph, T C

    2017-01-01

    The maximum operational range of continuous variable quantum key distribution protocols has shown to be improved by employing high-efficiency forward error correction codes. Typically, the secret key rate model for such protocols is modified to account for the non-zero word error rate of such codes. In this paper, we demonstrate that this model is incorrect: firstly, we show by example that fixed-rate error correction codes, as currently defined, can exhibit efficiencies greater than unity. Secondly, we show that using this secret key model combined with greater than unity efficiency codes, implies that it is possible to achieve a positive secret key over an entanglement breaking channel—an impossible scenario. We then consider the secret key model from a post-selection perspective, and examine the implications for key rate if we constrain the forward error correction codes to operate at low word error rates. (paper)

  18. Choice Of Exchange Rate Regimes For Developing Countries: Better Be Fixed Or Floating?

    Elif O. Kan

    2011-01-01

    The following paper is a summary article about the choice of exchange rate regime for a developing country considering the importance of currency mismatches, debt intolerance, and fear of floating, financial globalization, institutions and sudden stops. In this paper, I first summarize recent researches and papers on this specific issue. In a recent work of theirs, Calvo and Mishkin(2003) argue that much of the debate on choosing an exchange rate regime misses the boat and concludes that choi...

  19. Jet Inlet Efficiency

    2013-08-08

    AFRL-RW-EG-TR-2014-044 Jet Inlet Efficiency Nigel Plumb Taylor Sykes-Green Keith Williams John Wohleber Munitions Aerodynamics Sciences...CONTRACT NUMBER N/A 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) Nigel Plumb Taylor Sykes-Green Keith Williams John

  20. Fixed-Point Approximations of Bandwidth-Sharing Networks with Rate Constraints

    M. Frolkova (Masha); J. Reed (Josh); A.P. Zwart (Bert)

    2011-01-01

    htmlabstractBandwidth-sharing networks are important flow level models of communication networks. We focus on the fact that it takes a signicant number of users to saturate a link, necessitating the inclusion of individual rate constraints. In particular we extend work of Reed & Zwart on fluid

  1. THE DISCLOSURE OF THE CONVERSION OF VOLUME AND UTILIZATION OF FIXED CAPITAL IN THE COMMERCIAL RATE OF RETURN

    CONSTANTIN CĂRUNTU

    2010-01-01

    Full Text Available The efficiency and sustainability in a competitive economy are provided also by the extent to which the company has a material potential whose technical and operational parameters meet the new requirements of market economy. The management of creating value at the enterprise level requires selecting from a range of alternative investments that variant that incubated the most likely probability to increase the value of the firm. The fixed capital of the company is a production factor with a significant role in the performances of economic efficiency of it. The fixed capital incorporates a certain qualitative level of the production tehnologies and its effectiveness will depend decisively on the degree of physical and moral wear and also by the degree to which production capacity is used. At company level, economic efficiency is called return and, if the ratio between effect and effort is expressed as a percentage, is called rate of return. The key element of a company's profitability is the profit which, in its various forms, is taken into account in determining the different rates of return. The objective of any enterprise is to achieve maximum benefit and profitability of capital invested with the view to ensure its development and compensation of those who made capital investments. The profitability is one of the synthetic forms of expressing the efficiency of the entire financial-economic activities of the enterprise, respectively of all the means of production used and labor force, in all stages of economic circuit: supply, production and sales.

  2. Depreciation Rates for Australian Tractors and Headers - Is Machinery Depreciation a Fixed or Variable Cost?

    Tozer, Peter R.

    2005-01-01

    Seven different remaining value functions for tractors and harvesters were estimated using data from advertised prices for used farm equipment. The generalised Box-Cox model was used to nest six of the seven functions. The more complex Box- Cox function explained the data better, but simpler models such as the sum-of-theyears- digits, or double-square root models were no different and were easier to manipulate to estimate depreciation rates and costs. There were up to three components of depr...

  3. Do Generous Unemployment Benefit Programs Reduce Suicide Rates? A State Fixed-Effect Analysis Covering 1968–2008

    Cylus, Jonathan; Glymour, M. Maria; Avendano, Mauricio

    2014-01-01

    The recent economic recession has led to increases in suicide, but whether US state unemployment insurance programs ameliorate this association has not been examined. Exploiting US state variations in the generosity of benefit programs between 1968 and 2008, we tested the hypothesis that more generous unemployment benefit programs reduce the impact of economic downturns on suicide. Using state linear fixed-effect models, we found a negative additive interaction between unemployment rates and benefits among the US working-age (20–64 years) population (β = −0.57, 95% confidence interval: −0.86, −0.27; P unemployment rates on suicide is offset by the presence of generous state unemployment benefit programs, though estimated effects are small in magnitude. PMID:24939978

  4. Do generous unemployment benefit programs reduce suicide rates? A state fixed-effect analysis covering 1968-2008.

    Cylus, Jonathan; Glymour, M Maria; Avendano, Mauricio

    2014-07-01

    The recent economic recession has led to increases in suicide, but whether US state unemployment insurance programs ameliorate this association has not been examined. Exploiting US state variations in the generosity of benefit programs between 1968 and 2008, we tested the hypothesis that more generous unemployment benefit programs reduce the impact of economic downturns on suicide. Using state linear fixed-effect models, we found a negative additive interaction between unemployment rates and benefits among the US working-age (20-64 years) population (β = -0.57, 95% confidence interval: -0.86, -0.27; P unemployment rates on suicide is offset by the presence of generous state unemployment benefit programs, though estimated effects are small in magnitude. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Oral L-menthol reduces thermal sensation, increases work-rate and extends time to exhaustion, in the heat at a fixed rating of perceived exertion.

    Flood, T R; Waldron, M; Jeffries, O

    2017-07-01

    The study investigated the effect of a non-thermal cooling agent, L-menthol, on exercise at a fixed subjective rating of perceived exertion (RPE) in a hot environment. Eight male participants completed two trials at an exercise intensity between 'hard' and 'very hard', equating to 16 on the RPE scale at ~35 °C. Participants were instructed to continually adjust their power output to maintain an RPE of 16 throughout the exercise trial, stopping once power output had fallen by 30%. In a randomized crossover design, either L-menthol or placebo mouthwash was administered prior to exercise and at 10 min intervals. Power output, [Formula: see text]O 2 , heart rate, core and skin temperature was monitored, alongside thermal sensation and thermal comfort. Isokinetic peak power sprints were conducted prior to and immediately after the fixed RPE trial. Exercise time was greater (23:23 ± 3:36 vs. 21:44 ± 2:32 min; P = 0.049) and average power output increased (173 ± 24 vs. 167 ± 24 W; P = 0.044) in the L-menthol condition. Peak isokinetic sprint power declined from pre-post trial in the L-menthol l (9.0%; P = 0.015) but not in the placebo condition (3.4%; P = 0.275). Thermal sensation was lower in the L-menthol condition (P = 0.036), despite no changes in skin or core temperature (P > 0.05). These results indicate that a non-thermal cooling mouth rinse lowered thermal sensation, resulting in an elevated work rate, which extended exercise time in the heat at a fixed RPE.

  6. Global parameter optimization for maximizing radioisotope detection probabilities at fixed false alarm rates

    Portnoy, David, E-mail: david.portnoy@jhuapl.edu [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Feuerbach, Robert; Heimberg, Jennifer [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

    2011-10-01

    Today there is a tremendous amount of interest in systems that can detect radiological or nuclear threats. Many of these systems operate in extremely high throughput situations where delays caused by false alarms can have a significant negative impact. Thus, calculating the tradeoff between detection rates and false alarm rates is critical for their successful operation. Receiver operating characteristic (ROC) curves have long been used to depict this tradeoff. The methodology was first developed in the field of signal detection. In recent years it has been used increasingly in machine learning and data mining applications. It follows that this methodology could be applied to radiological/nuclear threat detection systems. However many of these systems do not fit into the classic principles of statistical detection theory because they tend to lack tractable likelihood functions and have many parameters, which, in general, do not have a one-to-one correspondence with the detection classes. This work proposes a strategy to overcome these problems by empirically finding parameter values that maximize the probability of detection for a selected number of probabilities of false alarm. To find these parameter values a statistical global optimization technique that seeks to estimate portions of a ROC curve is proposed. The optimization combines elements of simulated annealing with elements of genetic algorithms. Genetic algorithms were chosen because they can reduce the risk of getting stuck in local minima. However classic genetic algorithms operate on arrays of Booleans values or bit strings, so simulated annealing is employed to perform mutation in the genetic algorithm. The presented initial results were generated using an isotope identification algorithm developed at Johns Hopkins University Applied Physics Laboratory. The algorithm has 12 parameters: 4 real-valued and 8 Boolean. A simulated dataset was used for the optimization study; the 'threat' set of

  7. Global parameter optimization for maximizing radioisotope detection probabilities at fixed false alarm rates

    Portnoy, David; Feuerbach, Robert; Heimberg, Jennifer

    2011-01-01

    Today there is a tremendous amount of interest in systems that can detect radiological or nuclear threats. Many of these systems operate in extremely high throughput situations where delays caused by false alarms can have a significant negative impact. Thus, calculating the tradeoff between detection rates and false alarm rates is critical for their successful operation. Receiver operating characteristic (ROC) curves have long been used to depict this tradeoff. The methodology was first developed in the field of signal detection. In recent years it has been used increasingly in machine learning and data mining applications. It follows that this methodology could be applied to radiological/nuclear threat detection systems. However many of these systems do not fit into the classic principles of statistical detection theory because they tend to lack tractable likelihood functions and have many parameters, which, in general, do not have a one-to-one correspondence with the detection classes. This work proposes a strategy to overcome these problems by empirically finding parameter values that maximize the probability of detection for a selected number of probabilities of false alarm. To find these parameter values a statistical global optimization technique that seeks to estimate portions of a ROC curve is proposed. The optimization combines elements of simulated annealing with elements of genetic algorithms. Genetic algorithms were chosen because they can reduce the risk of getting stuck in local minima. However classic genetic algorithms operate on arrays of Booleans values or bit strings, so simulated annealing is employed to perform mutation in the genetic algorithm. The presented initial results were generated using an isotope identification algorithm developed at Johns Hopkins University Applied Physics Laboratory. The algorithm has 12 parameters: 4 real-valued and 8 Boolean. A simulated dataset was used for the optimization study; the 'threat' set of spectra

  8. Global parameter optimization for maximizing radioisotope detection probabilities at fixed false alarm rates

    Portnoy, David; Feuerbach, Robert; Heimberg, Jennifer

    2011-10-01

    Today there is a tremendous amount of interest in systems that can detect radiological or nuclear threats. Many of these systems operate in extremely high throughput situations where delays caused by false alarms can have a significant negative impact. Thus, calculating the tradeoff between detection rates and false alarm rates is critical for their successful operation. Receiver operating characteristic (ROC) curves have long been used to depict this tradeoff. The methodology was first developed in the field of signal detection. In recent years it has been used increasingly in machine learning and data mining applications. It follows that this methodology could be applied to radiological/nuclear threat detection systems. However many of these systems do not fit into the classic principles of statistical detection theory because they tend to lack tractable likelihood functions and have many parameters, which, in general, do not have a one-to-one correspondence with the detection classes. This work proposes a strategy to overcome these problems by empirically finding parameter values that maximize the probability of detection for a selected number of probabilities of false alarm. To find these parameter values a statistical global optimization technique that seeks to estimate portions of a ROC curve is proposed. The optimization combines elements of simulated annealing with elements of genetic algorithms. Genetic algorithms were chosen because they can reduce the risk of getting stuck in local minima. However classic genetic algorithms operate on arrays of Booleans values or bit strings, so simulated annealing is employed to perform mutation in the genetic algorithm. The presented initial results were generated using an isotope identification algorithm developed at Johns Hopkins University Applied Physics Laboratory. The algorithm has 12 parameters: 4 real-valued and 8 Boolean. A simulated dataset was used for the optimization study; the "threat" set of spectra

  9. Experimental Research on Optimizing Inlet Airflow of Wet Cooling Towers under Crosswind Conditions

    Chen, You Liang; Shi, Yong Feng; Hao, Jian Gang; Chang, Hao; Sun, Feng Zhong

    2018-01-01

    A new approach of installing air deflectors around tower inlet circumferentially was proposed to optimize the inlet airflow and reduce the adverse effect of crosswinds on the thermal performance of natural draft wet cooling towers (NDWCT). And inlet airflow uniformity coefficient was defined to analyze the uniformity of circumferential inlet airflow quantitatively. Then the effect of air deflectors on the NDWCT performance was investigated experimentally. By contrast between inlet air flow rate and cooling efficiency, it has been found that crosswinds not only decrease the inlet air flow rate, but also reduce the uniformity of inlet airflow, which reduce NDWCT performance jointly. After installing air deflectors, the inlet air flow rate and uniformity coefficient increase, the uniformity of heat and mass transfer increases correspondingly, which improve the cooling performance. In addition, analysis on Lewis factor demonstrates that the inlet airflow optimization has more enhancement of heat transfer than mass transfer, but leads to more water evaporation loss.

  10. Enhancing the Frequency Adaptability of Periodic Current Controllers with a Fixed Sampling Rate for Grid-Connected Power Converters

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2016-01-01

    Grid-connected power converters should employ advanced current controllers, e.g., Proportional Resonant (PR) and Repetitive Controllers (RC), in order to produce high-quality feed-in currents that are required to be synchronized with the grid. The synchronization is actually to detect...... of the resonant controllers and by approximating the fractional delay using a Lagrange interpolating polynomial for the RC, respectively, the frequency-variation-immunity of these periodic current controllers with a fixed sampling rate is improved. Experiments on a single-phase grid-connected system are presented...... the instantaneous grid information (e.g., frequency and phase of the grid voltage) for the current control, which is commonly performed by a Phase-Locked-Loop (PLL) system. Hence, harmonics and deviations in the estimated frequency by the PLL could lead to current tracking performance degradation, especially...

  11. Miniature piezo electric vacuum inlet valve

    Keville, Robert F.; Dietrich, Daniel D.

    1998-03-24

    A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

  12. Evaluation of bond strength and load deflection rate of multi-stranded fixed retainer wires: An In-Vitro Study

    Renu Sarah Samson

    2018-01-01

    Full Text Available Background: Fixed orthodontic retainers must be well retained on the tooth surfaces, allow physiologic movement of teeth and exert minimal forces on the teeth to be retained. Previous studies analyzed the bond strength and amount of deflection caused due to the debonding force but not the magnitude of force needed for unit deformation. Aims: This study aims to evaluate and compare the bond strength and load deflection rate (LDR of three different fixed retainer wires. Materials and Methods: The wires were divided into three Groups: A – three-stranded twisted ligature wire, B – Bond-A-Braid (Reliance Orthodontics, and C – three-stranded twisted lingual retainer wire (3M Unitek. Twenty models were prepared for each group with a passive 15 mm long lingual retainer wire bonded to two lower incisors. An occlusogingival force was applied to the wire until it debonded. For LDR, three-point bending test was done at 0.5 mm deflection. These forces were measured using a Universal Instron Testing Machine. Statistical Analysis: Mean bond strength/LDR and pairwise comparisons were analyzed with one-way ANOVA and Tukey's honest significant difference post hoc test, respectively. Results: Group C exhibited the highest mean bond strength and LDR of 101.17N and 1.84N, respectively. The intergroup comparisons were all statistically significant. Conclusion: Compared to the other two wire types, Group C might be better retained on the teeth due to its higher bond strength. With its relatively higher LDR value, it may resist deformation from occlusal forces, thereby reducing inadvertent tooth movement and yet remain flexible enough to allow physiologic tooth movements.

  13. Anaerobic digestion of corn ethanol thin stillage in batch and by high-rate down-flow fixed film reactors.

    Wilkinson, A; Kennedy, K J

    2012-01-01

    Thin stillage (CTS) from a dry-grind corn ethanol plant was evaluated as a carbon source for anaerobic digestion (AD) by batch and high rate semi-continuous down-flow stationary fixed film (DSFF) reactors. Biochemical methane potential (BMP) assays were carried out with CTS concentrations ranging from approximately 2,460-27,172 mg total chemical oxygen demand (TCOD) per litre, achieved by diluting CTS with clean water or a combination of clean water and treated effluent. High TCOD, SCOD and volatile solids (VS) removal efficiencies of 85 ± 2, 94 ± 0 and 82 ± 1% were achieved for CTS diluted with only clean water at an organic concentration of 21,177 mg TCOD per litre, with a methane yield of 0.30 L methane per gram TCOD(removed) at standard temperature and pressure (STP, 0 °C and 1 atmosphere). Batch studies investigating the use of treated effluent for dilution showed promising results. Continuous studies employed two mesophilic DSFF anaerobic digesters treating thin stillage, operated at hydraulic retention times (HRT) of 20, 14.3, 8.7, 6.3, 5 and 4.2 d. Successful digestion was achieved up to an organic loading rate (OLR) of approximately 7.4 g TCOD L(-1)d(-1) at a 5 d HRT with a yield of 2.05 LCH(4) L(-1)d(-1) (at STP) and TCOD and VS removal efficiencies of 89 ± 3 and 85 ± 3%, respectively.

  14. Social capital, income inequality and the social gradient in self-rated health in Latin America: A fixed effects analysis.

    Vincens, Natalia; Emmelin, Maria; Stafström, Martin

    2018-01-01

    Latin America is the most unequal region in the world. The current sustainable development agenda increased attention to health inequity and its determinants in the region. Our aim is to investigate the social gradient in health in Latin America and assess the effects of social capital and income inequality on it. We used cross-sectional data from the World Values Survey and the World Bank. Our sample included 10,426 respondents in eight Latin American countries. Self-rated health was used as the outcome. Education level was the socioeconomic position indicator. We measured social capital by associational membership, civic participation, generalized trust, and neighborhood trust indicators at both individual and country levels. Income inequality was operationalized using the Gini index at country-level. We employed fixed effects logistic regressions and cross-level interactions to assess the impact of social capital and income inequality on the heath gradient, controlling for country heterogeneity. Education level was independently associated with self-rated health, representing a clear social gradient in health, favoring individuals in higher socioeconomic positions. Generalized and neighborhood trust at country-level moderated the effect on the association between socioeconomic position and health, yet favoring individuals in lower socioeconomic positions, especially in lower inequality countries, despite their lower individual social capital. Our findings suggest that collective rather than individual social capital can impact the social gradient in health in Latin America, explaining health inequalities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Status of the variable diameter centerbody inlet program

    Saunders, John D.; Linne, A. A.

    1992-01-01

    The Variable Diameter Centerbody (VDC) inlet is an ongoing research program at LeRC. The VDC inlet is a mixed compression, axisymmetric inlet that has potential application on the next generation supersonic transport. This inlet was identified as one of the most promising axisymmetric concepts for supersonic cruise aircraft during the SCAR program in the late 1970's. Some of its features include high recovery, low bleed, good angle-of-attack tolerance, and excellent engine airflow matching. These features were demonstrated at LeRC in the past by the design and testing of fixed hardware models. A current test program in the LeRC 10' x 10' Supersonic Wind Tunnel (SWT) will attempt to duplicate these features on model hardware that actually incorporates a flight-like variable diameter centerbody mechanism.

  16. Hypersonic Combustor Model Inlet CFD Simulations and Experimental Comparisons

    Venkatapathy, E.; TokarcikPolsky, S.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)

    1995-01-01

    Numerous two-and three-dimensional computational simulations were performed for the inlet associated with the combustor model for the hypersonic propulsion experiment in the NASA Ames 16-Inch Shock Tunnel. The inlet was designed to produce a combustor-inlet flow that is nearly two-dimensional and of sufficient mass flow rate for large scale combustor testing. The three-dimensional simulations demonstrated that the inlet design met all the design objectives and that the inlet produced a very nearly two-dimensional combustor inflow profile. Numerous two-dimensional simulations were performed with various levels of approximations such as in the choice of chemical and physical models, as well as numerical approximations. Parametric studies were conducted to better understand and to characterize the inlet flow. Results from the two-and three-dimensional simulations were used to predict the mass flux entering the combustor and a mass flux correlation as a function of facility stagnation pressure was developed. Surface heat flux and pressure measurements were compared with the computed results and good agreement was found. The computational simulations helped determine the inlet low characteristics in the high enthalpy environment, the important parameters that affect the combustor-inlet flow, and the sensitivity of the inlet flow to various modeling assumptions.

  17. Numerical exploration of Kaldorian interregional macrodynamics: stability and the trade threshold for business cycles under fixed exchange rates.

    Asada, Toichiro; Douskos, Christos; Markellos, Panagiotis

    2011-01-01

    The stability of equilibrium and the possibility of generation of business cycles in a discrete interregional Kaldorian macrodynamic model with fixed exchange rates are explored using numerical methods. One of the aims is to illustrate the feasibility and effectiveness of the numerical approach for dynamical systems of moderately high dimensionality and several parameters. The model considered is five-dimensional with four parameters, the speeds of adjustment of the goods markets and the degrees of economic interactions between the regions through trade and capital movement. Using a grid search method for the determination of the region of stability of equilibrium in two-dimensional parameter subspaces, and coefficient criteria for the flip bifurcation - and Hopf bifurcation - curve, we determine the stability region in several parameter ranges and identify Hopf bifurcation curves when they exist. It is found that interregional cycles emerge only for sufficient interregional trade. The relevant threshold is predicted by the model at 14 - 16 % of trade transactions. By contrast, no minimum level of capital mobility exists in a global sense as a requirement for the emergence of interregional cycles; the main conclusion being, therefore, that cycles may occur for very low levels of capital mobility if trade is sufficient. Examples of bifurcation and Lyapunov exponent diagrams illustrating the occurrence of cycles or period doubling, and examples of the development of the occurring cycles, are given. Both supercritical and subcritical bifurcations are found to occur, the latter type indicating coexistence of a point and a cyclical attractor.

  18. Coastal inlets and tidal basins

    De Vriend, H.J.; Dronkers, J.; Stive, M.J.F.; Van Dongeren, A.; Wang, J.H.

    2002-01-01

    lecture note: Tidal inlets and their associated basins (lagoons) are a common feature of lowland coasts all around the world. A significant part ofthe world's coastlines is formed by barrier island coasts, and most other tidal coasts are interrupted by estuaries and lagoon inlets. These tidal

  19. Energy efficient air inlet humidity control; Energiezuinige inblaasvochtregeling

    Gielen, J.H. [C Point, DLV Plant, Horst (Netherlands)

    2005-03-15

    This project report describes the results of research conducted on the control of the inlet, humidification and dehumidification, based on the air inlet humidity rate. The project was carried out at a mushroom cultivation business in Heijen, the Netherlands [Dutch] Deze projectrapportage geeft de resultaten van het onderzoek naar het regelen van de luchtklep, bevochtiging en ontvochtiging, op basis van het inblaasvochtgehalte. Het project werd uitgevoerd op een champignonkwekerij in Heijen.

  20. Investigation on inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet

    Yang, Ce; Wang, Yingjun; Lao, Dazhong; Tong, Ding; Wei, Longyu; Liu, Yixiong

    2016-08-01

    The inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet structures were studied in numerical method, mainly focused on three issues including the amounts and differences of the inlet recirculation in different working conditions, the circumferential non-uniform distributions of the inlet recirculation, the recirculation velocity distributions of the upstream slot of the rear impeller. The results show that there are some differences between the recirculation of the front impeller and that of the rear impeller in whole working conditions. In design speed, the recirculation flow rate of the rear impeller is larger than that of the front impeller in the large flow range, but in the small flow range, the recirculation flow rate of the rear impeller is smaller than that of the front impeller. In different working conditions, the recirculation velocity distributions of the front and rear impeller are non-uniform along the circumferential direction and their non-uniform extents are quite different. The circumferential non-uniform extent of the recirculation velocity varies with the working conditions change. The circumferential non-uniform extent of the recirculation velocity of front impeller and its distribution are determined by the static pressure distribution of the front impeller, but that of the rear impeller is decided by the coupling effects of the inlet flow distortion of the rear impeller, the circumferential unsymmetrical distribution of the upstream slot and the asymmetric structure of the volute. In the design flow and small flow conditions, the recirculation velocities at different circumferential positions of the mean line of the upstream slot cross-section of the rear impeller are quite different, and the recirculation velocities distribution forms at both sides of the mean line are different. The recirculation velocity distributions in the cross-section of the upstream slot depend on the static pressure

  1. Performance study for inlet installations

    Bingaman, Donald C.

    1992-01-01

    A conceptual design trade study was conducted by McDonnell Aircraft Company (MCAIR) and NASA LARC PAB to determine the impact of inlet design features incorporated for reduced detectability on inlet performance, weight, and cost, for both fighter and attack-type aircraft. Quality Function Deployment (QFD) techniques were used to prioritize trade study issues, and select 'best' air induction system configurations for each of two notional aircraft, the Multi-Role Fighter (MRF) and the Advanced Medium Attack (AMA) bomber. Database deficiencies discovered in the trade study process were identified, and technology roadmaps were developed to address these deficiencies. Finally, two high speed inlet wind tunnel model concepts were developed for follow-on wind tunnel investigations.

  2. 7 CFR 1810.1 - Information concerning interest rates, amortization, guarantee fee, annual charge, and fixed period.

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Information concerning interest rates, amortization... UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS INTEREST RATES, TERMS, CONDITIONS, AND APPROVAL AUTHORITY Interest Rates, Amortization, Guarantee Fee, Annual Charge...

  3. Fixing the Central Parity and the Evolution of the Currency within the Exchange Rate Mechanism II in the Countries that Joined the Euro Zone

    Lucian ANGHEL

    2014-06-01

    Full Text Available The present paper presents the models used by the countries that joined the Euro zone after 2000, in fixing the central parity and the evolution of the local currency towards Euro, when participating in Exchange Rate Mechanism II (ERM II. It synthesizes the main theories for determining the equilibrium exchange rate. It also presents the modality of putting them into practice in the countries that had already become members of the Euro zone. The better we know the other countries’ experience in the respect of the joining process to the Euro zone, the better will Romania be able to prepare itself for adopting the unique European currency. Thus, we will be synthesize the main approaches within literature and also in the economic policy deciders’ practice concerning the estimation of the equilibrium exchange rate and implicitly, of the central parity. The paper presents the modality of fixing the central parity and the experience of participating in ERM II for a number of member states that joined the Euro zone after 2000: Greece, Slovakia, Slovenia, Malta, Cyprus and Estonia. For these states we also analyze the evolution of the currency towards Euro while participating in ERM II. Starting from these examples, we explain the advantages and the disadvantages in fixing the central parity over/at/under the value of the exchange rate on the market at the moment of joining ERM II and we underline the problems that might occur in the case of choosing a central parity that is not compatible with the equilibrium value of the exchange rate.

  4. Effect of the inlet throttling on the thermal-hydraulic instability of the natural circulation BWR

    Furuya, Masahiro; Inada, Fumio; Yoneda, Kimitoshi

    1997-01-01

    Although it is well-established that inlet restriction has a stabilizing for forced circulation BWR, the effect of inlet on the thermal-hydraulic stability of natural circulation BWR remains unknown since increasing inlet restriction affect thermal-hydraulic stability due to reduction of the recirculation flow rate. Therefore experiments have been conducted to investigate the effect of inlet restriction on the thermal-hydraulic stability. A test facility used in this experiments was designed and constructed to have non-dimensional values which are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation was described as a function of heat flux and inlet subcooling independent of inlet restriction. Stability maps in reference to the channel inlet subcooling, heat flux were presented for various inlet restriction which were carried out by an analysis based on the homogeneous flow various using this function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux. (author)

  5. "The stone which the builders rejected...": Delay of reinforcement and response rate on fixed-interval and related schedules.

    Wearden, J H; Lejeune, Helga

    2006-02-28

    The article deals with response rates (mainly running and peak or terminal rates) on simple and on some mixed-FI schedules and explores the idea that these rates are determined by the average delay of reinforcement for responses occurring during the response periods that the schedules generate. The effects of reinforcement delay are assumed to be mediated by a hyperbolic delay of reinforcement gradient. The account predicts that (a) running rates on simple FI schedules should increase with increasing rate of reinforcement, in a manner close to that required by Herrnstein's equation, (b) improving temporal control during acquisition should be associated with increasing running rates, (c) two-valued mixed-FI schedules with equiprobable components should produce complex results, with peak rates sometimes being higher on the longer component schedule, and (d) that effects of reinforcement probability on mixed-FI should affect the response rate at the time of the shorter component only. All these predictions were confirmed by data, although effects in some experiments remain outside the scope of the model. In general, delay of reinforcement as a determinant of response rate on FI and related schedules (rather than temporal control on such schedules) seems a useful starting point for a more thorough analysis of some neglected questions about performance on FI and related schedules.

  6. Geomorphic Analysis of Mattituck Inlet and Goldsmith Inlet, Long Island, New York

    Morgan, Michael J; Kraus, Nicholas C; McDonald, Jodi M

    2005-01-01

    This study of Mattituck Inlet and Goldsmith Inlet, Long Island, NY, covers the historic and geomorphic background, literature, field measurements, numerical modeling of tidal circulation, and analysis...

  7. Models comparative study for heat storage in fixed beds; Estudo comparativo de modelos para armazenamento de calor em leitos fixos

    Stuginski, Junior, Rubens

    1991-07-01

    This work presents comparative results of a numerical investigation of four possible models for the prediction of thermal performance of fixed bed storage units and their thermal design. These models includes Schumann's model, the radial dispersion model, a model that include both axial heat conduction in the fluid phase and admits thermal gradient in the solids particles and finally a two dimensional single phase model. For each of these models a computer code was written and tested to evaluate the computing time of same data and analyze any other computational problems. The tests of thermal performance included particle size, porosity, particle material, flow rate, inlet temperature and heat losses form tank walls and extremities. Dynamics behaviour of the storage units due to transient variation in either flow rate or inlet temperature was also investigated. The results presented include temperature gradients, pressure drop and heat storage. The results obtained are very useful for analysis and design of fixed bed storage units. (author)

  8. Fixed Points

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. Wave-driven fluxes through New River Inlet, NC

    Wargula, A.; Raubenheimer, B.; Elgar, S.

    2012-12-01

    The importance of wave forcing to inlet circulation is examined using observations of waves, water levels, and currents collected in and near New River Inlet, NC during April and May, 2012. A boat-mounted system was used to measure current profiles along transects across the inlet mouth during three 14-hr periods, providing information on cross-inlet current structure, as well as discharge. Additionally, an array of 13 colocated pressure gages and profilers were deployed along 2 km of the inlet channel (5 to 10 m water depths) and ebb shoal channel (2 to 3 m water depths) and 19 colocated pressure gages and acoustic Doppler velocimeters were deployed across and offshore of the ebb shoal (1 to 5 m water depths) (Figure 1). The inlet is well mixed and tidal currents ranged from +/- 1.5 m/s, maximum discharge rates at peak ebb and flood were about 700 to 900 m3/s, offshore significant wave heights Hsig were 0.5 to 2.5 m, and wind speeds ranged from 0 to 14 m/s. Time-integrated residual discharge over semi-diurnal tidal cycles with similar ranges was ebb dominant during calm conditions (May 11, net out-of-inlet discharge ~ 55 m3, Hsig ~ 0.5 m, NW winds ~ 3 m/s) and flood dominant during stormier conditions (May 14, net into-inlet discharge ~ 15 m3, Hsig ~ 1.2 m, S winds ~ 6.5 m/s). Low-pass filtered in situ profiler data suggest wave-forcing affects the fluxes into and out of the inlet. The observations will be used to examine the momentum balance governing the temporal and cross-inlet (channel vs. shoal) variation of these fluxes, as well as the effect of waves on ebb and flood flow dominance. Funding provided by the Office of Naval Research and a National Security Science and Engineering Faculty Fellowship.; Figure 1: Google Earth image of New River Inlet, NC. Colors are depth contours (scale on the right, units are m relative to mean sea level) and symbols are locations of colocated current meters and pressure gages.

  10. Evaluation of magnetic resonance imaging in thoracic inlet tumors

    Sakai, Eiro (Kobe Univ. (Japan). School of Medicine)

    1993-06-01

    To evaluate the detectability of tumor invasion to the thoracic inlet, MRI was performed in 57 patients with thoracic inlet tumor, and the diagnostic accuracy of MRI was compared with that of CT concerning the utility for thoracic inlet lesions. And we assessed abnormal findings in comparison with surgical or autopsy findings. In the local extent of the tumor, the accuracy for tumor invasion to the vessels such as subclavian artery and vein was 94.9% for MRI, and 83.5% for CT, and to the brachial plexus was 95.0% for MRI, and 60.0% for CT. MRI was superior to CT, but MRI was equivalent to CT with regard to invasion to the base of the neck, lateral chest wall, ribs, and vertebral bodies. However on MRI, it is easier to understand the longitudinal tumor extent than on CT. CT has superior spatial resolusion but CT has also disadvantages, such as streak artifact caused by shoulder joints, resulting in image degradation. In contrast, MRI has inherent advantages, and multiple images which facilitate the relationship between tumor and normal structures. Coronal and sagittal MR images facilitated three-dimensional observation of tumor of invasion in the thoracic inlet. Furthermore to improve image quality of MRI for the thoracic inlet, we newly devised a high molecular polyester shell for fixing a surface coil. On the high resolution MR (HR-MR) imaging using our shell, normal lymph nodes, muscles, blood vessels and the branches of the branchial plexus were clearly visualized in detail. Our shell was simple to process and facilitated immobilization of a surface coil. HR-MR technique produces images of high resolution after simple preparation. In conclusion, MRI was very useful for detecting lesions of the thoracic inlet and in deciding surgical indication and the planning for radiotherapy. (author).

  11. Dynamic Effect of a Change in the Exchange Rate System: From a Fixed Regime to a Basket-Peg or a Floating Regime

    Yoshino, Naoyuki; Kaji, Sahoko; Asonuma, Tamon

    2015-01-01

    This paper theoretically evaluates the dynamic effects of a shift in an exchange rate system from a fixed regime to a basket peg, or to a floating regime, and obtains transition paths for the shift based on a dynamic stochastic general equilibrium model of a small open economy. We apply quantitative analysis using data from the People's Republic of China and Thailand and find that a small open country would be better off shifting to a basket peg or to a floating regime than maintaining a doll...

  12. THE IMPLICATIONS OF GROSS FIXED CAPITAL AND UNEMPLOYMENT RATE ON GENERAL GOVERNMENT DEFICIT. EMPIRICAL STUDY AT THE EUROPEAN LEVEL

    Mihai Carp

    2010-12-01

    Full Text Available In this paper we have evaluated the influence of the modification of public investment level and unemployment rate on the general government deficit at the European Union level. We have created a regression model that shows that a sustained and increased investment policy and the reduction of unemployment rate have a favorable effect on the objective of minimizing the budget deficit. In the last years European Union’s countries had to face a difficult problem concerning fiscal policy. They had to make public investments to stimulate economic growth and, in the same time, they had to meet the convergence criteria’s of public deficit. On the other hand, EU has to deal with a higher rate of unemployment. Through our model we try to see how European Union countries should implement their political strategies on unemployment and investment with the main objective of reducing the general government deficit.

  13. Inlet effect induced ''upstream'' critical heat flux in smooth tubes

    Kitto, J.B. Jr.

    1986-01-01

    An unusual form of ''upstream'' critical heat flux (CHF) has been observed and directly linked to the inlet flow pattern during an experimental study of high pressure (17 - 20 MPa) water flowing through a vertical 38.1 mm ID smooth bore tube with uniform axial and nonuniform circumferential heating. These upstream CHF data were characterized by temperature excursions which initially occurred at a relatively fixed axial location in the middle of the test section while the outlet and inlet heated lengths experienced no change. A rifled tube inlet flow conditioner could be substituted for a smooth tube section to generate the desired swirling inlet flow pattern. The upstream CHF data were found to match data from a uniformly heated smooth bore tube when the comparison was made using the peak local heat flux. The mechanism proposed to account for the upstream CHF observations involves the destructive interference between the decaying swirl flow and the secondary circumferential liquid flow field resulting from the one-sided heating

  14. Long-Term Results of Fixed High-Dose I-131 Treatment for Toxic Nodular Goiter: Higher Euthyroidism Rates in Geriatric Patients

    Gül Ege Aktaş

    2015-10-01

    Full Text Available Objective: Geriatric patient population has special importance due to particular challenges. In addition to the increase in incidence of toxic nodular goiter (TNG with age, it has a high incidence in the regions of low-medium iodine intake such as in our country. The aim of this study was to evaluate the overall outcome of high fixed dose radioiodine (RAI therapy, and investigate the particular differences in the geriatric patient population. Methods: One hundred and three TNG patients treated with high dose I-131 (370-740 MBq were retrospectively reviewed. The baseline characteristics; age, gender, scintigraphic patterns and thyroid function tests before and after treatment, as well as follow-up, duration of antithyroid drug (ATD medication and achievement of euthyroid or hypothyroid state were evaluated. The patient population was divided into two groups as those=>65 years and those who were younger, in order to assess the effect of age. Results: Treatment success was 90% with single dose RAI therapy. Hyperthyroidism was treated in 7±7, 2 months after RAI administration. At the end of the first year, overall hypothyroidism rate was 30% and euthyroid state was achieved in 70% of patients. Age was found to be the only statistically significant variable effecting outcome. A higher ratio of euthyroidism was achieved in the geriatric patient population. Conclusion: High fixed dose I-131 treatment should be preferred in geriatric TNG patients in order to treat persistent hyperthyroidism rapidly. The result of this study suggests that high fixed dose RAI therapy is a successful modality in treating TNG, and high rates of euthyroidism can be achieved in geriatric patients.

  15. Fix 40!

    2008-01-01

    Ansambel Fix peab 13. detsembril Tallinnas Saku Suurhallis oma 40. sünnipäeva. Kontserdi erikülaline on ansambel Apelsin, kaastegevad Jassi Zahharov ja HaleBopp Singers. Õhtut juhib Tarmo Leinatamm

  16. Compressive sensing-based wideband capacitance measurement with a fixed sampling rate lower than the highest exciting frequency

    Xu, Lijun; Ren, Ying; Sun, Shijie; Cao, Zhang

    2016-01-01

    In this paper, an under-sampling method for wideband capacitance measurement was proposed by using the compressive sensing strategy. As the excitation signal is sparse in the frequency domain, the compressed sampling method that uses a random demodulator was adopted, which could greatly decrease the sampling rate. Besides, four switches were used to replace the multiplier in the random demodulator. As a result, not only the sampling rate can be much smaller than the signal excitation frequency, but also the circuit’s structure is simpler and its power consumption is lower. A hardware prototype was constructed to validate the method. In the prototype, an excitation voltage with a frequency up to 200 kHz was applied to a capacitance-to-voltage converter. The output signal of the converter was randomly modulated by a pseudo-random sequence through four switches. After a low-pass filter, the signal was sampled by an analog-to-digital converter at a sampling rate of 50 kHz, which was three times lower than the highest exciting frequency. The frequency and amplitude of the signal were then reconstructed to obtain the measured capacitance. Both theoretical analysis and experiments were carried out to show the feasibility of the proposed method and to evaluate the performance of the prototype, including its linearity, sensitivity, repeatability, accuracy and stability within a given measurement range. (paper)

  17. Rate of Clinical Complete Response for 1 Year or More in Bone-Metastatic Breast Cancer after Comprehensive Treatments including Autologous Formalin-Fixed Tumor Vaccine.

    Kuranishi, Fumito; Imaoka, Yuki; Sumi, Yuusuke; Uemae, Yoji; Yasuda-Kurihara, Hiroko; Ishihara, Takeshi; Miyazaki, Tsubasa; Ohno, Tadao

    2018-01-01

    No effective treatment has been developed for bone-metastatic breast cancer. We found 3 cases with clinical complete response (cCR) of the bone metastasis and longer overall survival of the retrospectively examined cohort treated comprehensively including autologous formalin-fixed tumor vaccine (AFTV). AFTV was prepared individually for each patient from their own formalin-fixed and paraffin-embedded breast cancer tissues. Three patients maintained cCR status of the bone metastasis for 17 months or more. Rate of cCR for 1 year or more appeared to be 15% (3/20) after comprehensive treatments including AFTV. The median overall survival time (60.0 months) and the 3- to 8-year survival rates after diagnosis of bone metastasis were greater than those of historical control cohorts in Japan (1988-2002) and in the nationwide population-based cohort study of Denmark (1999-2007). Bone-metastatic breast cancer may be curable after comprehensive treatments including AFTV, although larger scale clinical trial is required.

  18. Rate of Clinical Complete Response for 1 Year or More in Bone-Metastatic Breast Cancer after Comprehensive Treatments including Autologous Formalin-Fixed Tumor Vaccine

    Fumito Kuranishi

    2018-01-01

    Full Text Available Introduction. No effective treatment has been developed for bone-metastatic breast cancer. We found 3 cases with clinical complete response (cCR of the bone metastasis and longer overall survival of the retrospectively examined cohort treated comprehensively including autologous formalin-fixed tumor vaccine (AFTV. Patients and Methods. AFTV was prepared individually for each patient from their own formalin-fixed and paraffin-embedded breast cancer tissues. Results. Three patients maintained cCR status of the bone metastasis for 17 months or more. Rate of cCR for 1 year or more appeared to be 15% (3/20 after comprehensive treatments including AFTV. The median overall survival time (60.0 months and the 3- to 8-year survival rates after diagnosis of bone metastasis were greater than those of historical control cohorts in Japan (1988–2002 and in the nationwide population-based cohort study of Denmark (1999–2007. Conclusion. Bone-metastatic breast cancer may be curable after comprehensive treatments including AFTV, although larger scale clinical trial is required.

  19. Ovarian responses and pregnancy rate with previously used intravaginal progesterone releasing devices for fixed-time artificial insemination in sheep.

    Vilariño, M; Rubianes, E; Menchaca, A

    2013-01-01

    The objective was to determine serum progesterone concentrations, ovarian responses, and pregnancy rate in sheep inseminated following a short-term protocol (6 days of treatment) with a previously used controlled internal drug release-G (CIDR-G) device. In experiment 1, 30 ewes were put on a short-term protocol using a CIDR-G of first use (new devices, N = 10), second use (previously used for 6 days, N = 10), or third use (previously used twice for 6 days, N = 10). All ewes were given prostaglandin F(2α) (10 mg dinoprost) and eCG (300 IU) im at device withdrawal. Mean serum progesterone concentrations were greater for ewes treated with new versus reused devices (P synchronization and ovulation, with lower serum progesterone concentrations for reused devices. Three times used CIDR-G yielded a pregnancy rate >70%, which tended to be lower than that obtained with new devices, adding evidence of the detrimental effect of low serum progesterone concentrations on fertility in sheep. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Inlet design for high-speed propfans

    Little, B. H., Jr.; Hinson, B. L.

    1982-01-01

    A two-part study was performed to design inlets for high-speed propfan installation. The first part was a parametric study to select promising inlet concepts. A wide range of inlet geometries was examined and evaluated - primarily on the basis of cruise thrust and fuel burn performance. Two inlet concepts were than chosen for more detailed design studies - one apropriate to offset engine/gearbox arrangements and the other to in-line arrangements. In the second part of this study, inlet design points were chosen to optimize the net installed thrust, and detailed design of the two inlet configurations was performed. An analytical methodology was developed to account for propfan slipstream effects, transonic flow efects, and three-dimensional geometry effects. Using this methodology, low drag cowls were designed for the two inlets.

  1. Parametric Data from a Wind Tunnel Test on a Rocket-Based Combined-Cycle Engine Inlet

    Fernandez, Rene; Trefny, Charles J.; Thomas, Scott R.; Bulman, Mel J.

    2001-01-01

    A 40-percent scale model of the inlet to a rocket-based combined-cycle (RBCC) engine was tested in the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT). The full-scale RBCC engine is scheduled for test in the Hypersonic Tunnel Facility (HTF) at NASA Glenn's Plum Brook Station at Mach 5 and 6. This engine will incorporate the configuration of this inlet model which achieved the best performance during the present experiment. The inlet test was conducted at Mach numbers of 4.0, 5.0, 5.5, and 6.0. The fixed-geometry inlet consists of an 8 deg.. forebody compression plate, boundary layer diverter, and two compressive struts located within 2 parallel sidewalls. These struts extend through the inlet, dividing the flowpath into three channels. Test parameters investigated included strut geometry, boundary layer ingestion, and Reynolds number (Re). Inlet axial pressure distributions and cross-sectional Pitot-pressure surveys at the base of the struts were measured at varying back-pressures. Inlet performance and starting data are presented. The inlet chosen for the RBCC engine self-started at all Mach numbers from 4 to 6. Pitot-pressure contours showed large flow nonuniformity on the body-side of the inlet. The inlet provided adequate pressure recovery and flow quality for the RBCC cycle even with the flow separation.

  2. Nitrogen Fixed by Pea Plant as Affected by Lead,Cadmium and Rates of N-Fertilizer Using 15N Tracer Technique

    Ismail, M.M.; El-Degwy, S.M.; Abdel-Aziz, H.A.; Elbaz, A.S.

    2012-01-01

    A pot experiment was carried out in greenhouse to investigate the effect Pb and Cd applied on growth, yield and the amount of fixed nitrogen by pea's plants. 15 N-labelled (5 % atom excess) ammonium nitrate was applied at three levels (0,20 and 40 mg N -1 kg soil). The legume pea seeds were inoculated with Rhizobium Leguminesarum. Lead was applied as lead sulfate at rates of 0, 50 and 200 mg Pb kg -1 soil, while the cadmium applied as cadmium sulfate at rates of 0, 5 and 10 mg Cd kg -1 soil. Results indicated that the highest values of Pb uptake were 540,11.55 and 552 mg -1 pot for pea shoot, pods and whole plant at the rate of 200 mg Pb kg -1 soil + 40 mg N kg -1 soil, respectively, While, the highest values of Cd-uptake were 13.90, 6.54 and 20 mg -1 pot at the rate of 10 mg Cd kg -1 + 20 mg N kg -1 soil for the same sequence. The values of Ndff and Ndfa were 43.74 and 278.2 while Ndfs recorded 164.1 mg pot -1 at rate of 5 mg Cd kg -1 soil + 40 mg N kg -1 soil compared to the control.

  3. A Phase II Study of Fixed-Dose Rate Gemcitabine Plus Low-Dose Cisplatin Followed by Consolidative Chemoradiation for Locally Advanced Pancreatic Cancer

    Ko, Andrew H.; Quivey, Jeanne M.; Venook, Alan P.; Bergsland, Emily K.; Dito, Elizabeth R.N.; Schillinger, Brian R.N.; Tempero, Margaret A.

    2007-01-01

    Purpose: The optimal strategy for treating locally advanced pancreatic cancer remains controversial, including the respective roles and timing of chemotherapy and radiation. We conducted a Phase II nonrandomized trial to evaluate sequential chemotherapy followed by chemoradiation in this patient population. Methods and Materials: Chemotherapy naive patients with locally advanced pancreatic adenocarcinoma were treated with fixed-dose rate gemcitabine (1,000 mg/m 2 at 10 mg/m 2 /min) plus cisplatin 20 mg/m 2 on Days 1 and 15 of a 28-day cycle. Those without evidence of extrapancreatic metastases after six cycles of chemotherapy received radiation (5,040 cGy over 28 fractions) with concurrent capecitabine (800 mg/m 2 orally twice daily on the day of radiation) as a radiosensitizer. Results: A total of 25 patients were enrolled with a median follow-up time of 656 days. Twelve patients (48%) successfully received all six cycles of chemotherapy plus chemoradiation. Eight patients (32%) progressed during chemotherapy, including 7 with extrapancreatic metastases. Grade 3/4 hematologic toxicities were uncommon. Two patients sustained myocardial infarctions during chemotherapy, and 4 were hospitalized for infectious complications, although none in the setting of neutropenia. Median time to progression was 10.5 months and median survival was 13.5 months, with an estimated 1-year survival rate of 62%. Patients receiving all components of therapy had a median survival of 17.0 months. Conclusions: A strategy of initial fixed-dose rate gemcitabine-based chemotherapy, followed by chemoradiation, shows promising efficacy for treatment of locally advanced disease. A substantial proportion of patients will be identified early on as having extrapancreatic disease and spared the potential toxicities associated with radiation

  4. Retrospective comparative ten-year study of cumulative survival rates of remaining teeth in large edentulism treated with implant-supported fixed partial dentures or removable partial dentures.

    Yamazaki, Seiya; Arakawa, Hikaru; Maekawa, Kenji; Hara, Emilio Satoshi; Noda, Kinji; Minakuchi, Hajime; Sonoyama, Wataru; Matsuka, Yoshizo; Kuboki, Takuo

    2013-07-01

    This study aimed to compare the survival rates of remaining teeth between implant-supported fixed dentures (IFDs) and removable partial dentures (RPDs) in patients with large edentulous cases. The second goal was to assess the risk factors for remaining tooth loss. The study subjects were selected among those who received prosthodontic treatment at Okayama University Dental Hospital for their edentulous space exceeding at least four continuous missing teeth. Twenty-one patients were included in the IFD group and 82 patients were included in the RPD group. Survival rates of remaining teeth were calculated in three subcategories: (1) whole remaining teeth, (2) adjacent teeth to intended edentulous space, and (3) opposing teeth to intended edentulous space. The ten-year cumulative survival rate of the whole remaining teeth was significantly higher in the IFD group (40.0%) than in the RPD group (24.4%). On the other hand, there was no significant difference between two groups in the survival rate of teeth adjacent or opposing to intended edentulous space. A Cox proportional hazard analysis revealed that RPD restoration and gender (male) were the significant risk factors for remaining tooth loss (whole remaining teeth). These results suggest that IFD treatment can reduce the incidence of remaining tooth loss in large edentulous cases. Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  5. Jet Engine Fan Response to Inlet Distortions Generated by Ingesting Boundary Layer Flow

    Giuliani, James Edward

    . Total pressure profiles at various axial locations are computed to identify the overall distortion pattern, how the distortion evolves through the blade passages and mixes out downstream of the blades, and where any critical performance concerns might be. Stall cells are identified that are stationary in the absolute frame and are fixed to the inlet distortion. Flow paths around the blades are examined to study the stall mechanism. Rather than a static airfoil stall, it is observed that the non-uniform pressure loading promotes a three-dimensional dynamic stall. The stall occurs at a point of rapid incidence angle oscillation, observed when a blade passes through the distortion, and re-attaches when the blade leaves the distortion.

  6. Implant and prosthodontic survival rates with implant fixed complete dental prostheses in the edentulous mandible after at least 5 years: a systematic review.

    Papaspyridakos, Panos; Mokti, Muizzaddin; Chen, Chun-Jung; Benic, Goran I; Gallucci, German O; Chronopoulos, Vasilios

    2014-10-01

    The treatment of mandibular edentulism with implant fixed complete dental prostheses (IFCDPs) is a routinely used treatment option. The study aims to report the implant and prosthodontic survival rates associated with IFCDPs for the edentulous mandible after an observation period of a minimum 5 years. An electronic MEDLINE/PubMED search was conducted to identify randomized controlled clinical trials and prospective studies with IFCDPs for the edentulous mandible. Clinical studies with at least 5-year follow-up were selected. Pooled data were statistically analyzed and cumulative implant- and prosthesis survival rates were calculated by meta-analysis, regression, and chi-square statistics. Implant-related and prosthesis-related factors were identified and their impact on survival rates was assessed. Seventeen prospective studies, including 501 patients and 2,827 implants, were selected for meta-analysis. The majority of the implants (88.5% of all placed implants) had been placed in the interforaminal area. Cumulative implant survival rates for rough surface ranged from 98.42% (95% confidence interval [CI]: 97.98-98.86) (5 years) to 96.86% (95% CI: 96.00-97.73) (10 years); smooth surface implant survival rates ranged from 98.93% (95% CI: 98.38-99.49) (5 years) to 97.88% (95% CI: 96.78-98.98) (10 years). The prosthodontic survival rates for 1-piece IFCDPs ranged from 98.61% (95% CI: 97.80-99.43) (5 years) to 97.25% (95% CI: 95.66-98.86) (10 years). Treatment with mandibular IFCDPs yields high implant and prosthodontic survival rates (more than 96% after 10 years). Rough surface implants exhibited cumulative survival rates similar to the smooth surface ones (p > .05) in the edentulous mandible. The number of supporting implants and the antero-posterior implant distribution had no influence (p > .05) on the implant survival rate. The prosthetic design and veneering material, the retention type, and the loading protocol (delayed, early, and immediate) had no

  7. Sediment Budget Analysis; Masonboro Inlet, North Carolina

    2017-08-15

    ER D C/ CH L TR -1 7- 13 Regional Sediment Management (RSM) Program Sediment Budget Analysis; Masonboro Inlet, North Carolina Co as ta...ERDC/CHL TR-17-13 August 2017 Sediment Budget Analysis; Masonboro Inlet, North Carolina Kevin B. Conner U.S. Army Engineer District, Wilmington P...Engineers Washington, DC 20314-1000 Under Project 454632, “Sediment Budget Analysis, Masonboro Inlet, NC” ERDC/CHL TR-17-13 ii Abstract A

  8. Block-and-break generation of microdroplets with fixed volume

    van Steijn, Volkert; Korczyk, Piotr M.; Derzsi, Ladislav; Abate, Adam R.; Weitz, David A.; Garstecki, Piotr

    2013-01-01

    We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets. PMID:24404013

  9. Interactions Between Wetlands and Tidal Inlets

    Sanchez, Alejandro

    2008-01-01

    This Coastal and Hydraulics Engineering Technical Note (CHETN) presents numerical simulations investigating how the loss of wetlands in estuaries modifies tidal processes in inlet navigation channels...

  10. Pregnancy rate evaluation in lactating and non-lactating Nelore cows subjected to fixed-time artificial insemination using injectable progesterone

    Jefferson Tadeu Campos

    2016-08-01

    Full Text Available Most fixed-time artificial insemination (FTAI protocols utilize progesterone (P4 as a hormonal source to achieve synchronization of estrus in cattle. The use of an injectable P4 source to control estrus would be an interesting pharmacological strategy owing to the practicality of parenteral application. However, the effects of injectable P4 on estrus cycle control in cattle remain poorly studied. In particular, no existing studies have investigated the effect of injectable P4 on the fertility of cows subjected to FTAI. The aim of this study was to evaluate the pregnancy rate of lactating and non-lactating Nelore cows subjected to FTAI with injectable P4. Of the 422 non-lactating cows in this study, 162 (38.3% became pregnant by 60 days post-FTAI. In the lactating group (n = 516, 166 (32.1% were pregnant by 60 days after treatment with injectable P4. The proportions of lactating and non-lactating cows becoming pregnant were compared using the chi-square test, adopting a significance level of P < 0.05. It was found that the pregnancy rate of the cows subjected to FTAI with injectable P4 was influenced by lactation status. Lactating cows had lower reproductive performance, possibly because of their higher nutritional requirements. However, the use of injectable P4 shows promising results and may prove to be a useful strategy in large-scale livestock production.

  11. Aerosol Inlet Characterization Experiment Report

    Bullard, Robert L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kuang, Chongai [Brookhaven National Lab. (BNL), Upton, NY (United States); Uin, Janek [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-05-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerosol Observation System inlet stack was characterized for particle penetration efficiency from 10 nm to 20 μm in diameter using duplicate scanning mobility particle sizers (10 nm-450 nm), ultra-high-sensitivity aerosol spectrometers (60 nm-μm), and aerodynamic particle sizers (0.5 μm-20 μm). Results show good model-measurement agreement and unit transmission efficiency of aerosols from 10 nm to 4 μm in diameter. Large uncertainties in the measured transmission efficiency exist above 4 μm due to low ambient aerosol signal in that size range.

  12. The effect of inlet distorted flow on steady and unsteady performance of a centrifugal compressor

    Park, Jae Hyoung; Kang, Shin Hyoung

    2005-01-01

    Effects of inlet distorted flow on performance, stall and surge are experimentally investigated for a high-speed centrifugal compressor. Tested results for the distorted inlet flow cases are compared with the result of the undistorted one. The performance of compressor is slightly deteriorated due to the inlet distortion. The inlet distortion does not affect the number of stall cell and the propagation velocity. It also does not change stall inception flow rate. However, as the distortion increases, stall starts at the higher flow rate for low speed at the lower flow rate for high speed. For 50,000 rpm stall occurs as the flow rate decreases, however disappears for the smaller flow rate. This is due to the interaction of surge and stall. After the stall and surge interact, the number of stall cell decreases

  13. Brazos Santiago Inlet, Texas, Shoaling Study

    2018-02-01

    Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199 Final report Approved for public release; distribution is unlimited. Prepared...focus of this study was to understand the shoaling process in the BSI and to suggest sand management alternatives to reduce inlet maintenance ...Santiago Inlet Entrance Channel maintenance dredging quantities (normal distribution). ........................................................ 20

  14. Survival rates of IPS empress 2 all-ceramic crowns and fixed partial dentures: results of a 5-year prospective clinical study.

    Marquardt, Pascal; Strub, Jörg Rudolf

    2006-04-01

    The aim of this prospective clinical study was to evaluate the survival rates of IPS Empress 2 (Ivoclar Vivadent) all-ceramic crowns and fixed partial dentures (FPDs) after an observation period of up to 5 years. Forty-three patients (19 women and 24 men) were included in this study. The patients were treated with a total of 58 adhesive bonded IPS Empress 2 restorations. A total of 27 single crowns were placed on molars and premolars, and 31 three-unit FPDs were placed in the anterior and premolar regions. Clinical follow-up examinations took place at 6, 12, 24, 36, 48, and 60 months after insertion. Statistical analysis of the data was calculated using the Kaplan-Meier method. Results of the 50-month analysis (interquartile range, 33 to 61 months) showed that the survival rate was 100% for crowns and 70% for FPDs. Six failures that occurred exclusively in the three-unit FPDs were observed. Framework fractures were recorded in three FPD units where the connector dimensions did not meet the manufacturer specifications. Only one FPD exhibited an irreparable partial veneer fracture, and 2 FPDs showed evidence of biologic failures. The accuracy of fit and esthetic parameters were clinically satisfactory for crowns and FPDs. The results of this 5-year clinical evaluation suggest that IPS Empress 2 ceramic is an appropriate material for the fabrication of single crowns. Because of the reduced survival rates, strict conditions should be considered before the use of IPS Empress 2 material for the fabrication of three-unit FPDs.

  15. All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part I: Single crowns (SCs).

    Sailer, Irena; Makarov, Nikolay Alexandrovich; Thoma, Daniel Stefan; Zwahlen, Marcel; Pjetursson, Bjarni Elvar

    2015-06-01

    To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported single crowns (SCs) and to describe the incidence of biological, technical and esthetic complications. Medline (PubMed), Embase, Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported fixed dental prostheses (FDPs) with a mean follow-up of at least 3 years. This was complimented by an additional hand search and the inclusion of 34 studies from a previous systematic review [1,2]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. Sixty-seven studies reporting on 4663 metal-ceramic and 9434 all-ceramic SCs fulfilled the inclusion criteria. Seventeen studies reported on metal-ceramic crowns, and 54 studies reported on all-ceramic crowns. Meta-analysis of the included studies indicated an estimated survival rate of metal-ceramic SCs of 94.7% (95% CI: 94.1-96.9%) after 5 years. This was similar to the estimated 5-year survival rate of leucit or lithium-disilicate reinforced glass ceramic SCs (96.6%; 95% CI: 94.9-96.7%), of glass infiltrated alumina SCs (94.6%; 95% CI: 92.7-96%) and densely sintered alumina and zirconia SCs (96%; 95% CI: 93.8-97.5%; 92.1%; 95% CI: 82.8-95.6%). In contrast, the 5-year survival rates of feldspathic/silica-based ceramic crowns were lower (pceramic and zirconia crowns exhibited significantly lower survival rates in the posterior region (pceramic fractures than metal-ceramic SCs (pceramic SCs than for metal-ceramic SCs. Survival rates of most types of all-ceramic SCs were similar to those reported for metal-ceramic SCs, both in anterior and posterior regions. Weaker feldspathic/silica-based ceramics should be limited to applications in the anterior region. Zirconia-based SCs should not be considered as primary option due to their high incidence of technical problems. Copyright © 2015 Academy

  16. Microjet flow control in an ultra-compact serpentine inlet

    Da Xingya

    2015-10-01

    Full Text Available Microjets are used to control the internal flow to improve the performance of an ultra-compact serpentine inlet. A highly offset serpentine inlet with length-to-diameter ratio of 2.5 is designed and static tests are conducted to analyze the internal flow characteristics in terms of pressure recovery, distortion and flow separation. Flow separation is encountered in the second S-turn, and two strong counter-rotating vortices are formed at the aerodynamic interface plane (AIP face which occupy a quarter of the outlet area and result in severe pressure loss and distortion. A flow control model employing a row of microjets in the second turn is designed based on the internal flow characteristics and simplified CFD simulations. Flow control tests are conducted to verify the control effectiveness and understand the characteristics as a function of inlet throat Mach number, injection mass flow ratio, jet Mach number and momentum coefficient. At all test Mach numbers, microjet flow control (MFC effectively improves the recovery and reduces the distortion intensity. Between inlet throat Mach number 0.2 and 0.5, the strong flow separation in the second S-turn is suppressed at an optimum jet flow ratio of less than 0.65%, resulting in a maximum improvement of 4% for pressure recovery coefficient and a maximum decrease of 75% for circumferential distortion intensity at cruise. However, in order to suppress the flow separation, the injection rate should retain in an effective range. When the injection rate is higher than this range, the flow is degraded and the distortion contour is changed from 90° circumferential distortion pattern to 180° circumferential distortion pattern. Detailed data analysis shows that this optimum flow ratio depends on inlet throat Mach number and the momentum coefficient affects the control effectiveness in a dual stepping manner.

  17. Analytical and Experimental Investigation of Inlet-engine Matching for Turbojet-powered Aircraft at Mach Numbers up to 2.0

    Esenwein, Fred T; Schueller, Carl F

    1952-01-01

    An analysis of inlet-turbojet-engine matching for a range of Mach numbers up to 2.0 indicates large performance penalties when fixed-geometry inlets are used. Use of variable-geometry inlets, however, nearly eliminates th The analysis was confirmed experimentally by investigating at Mach numbers of 0, 0.63, and 1.5 to 2.0 two single oblique-shock-type inlets of different compression-ramp angles, which simulated a variable-geometry configuration. The experimental investigation indicated that total-pressure recoveries comparable withose attainable with well designed nose inlets were obtained with the side inlets when all the boundary layer ahead of the inlets was removed. Serious drag penalties resulted at a Mach number of 2.0 from the use of blunt-cowl leading edges. However, sharp-lip inlets produced large losses in thrust for the take-off condition. These thrust penalties which are associated with the the low-speed operation of the sharp-lip inlet designs can probably be avoided without impairing the supersonic performance of the inlet by the use of auxiliary inlets or blow-in doors.

  18. Ten-year survival and complication rates of lithium-disilicate (Empress 2) tooth-supported crowns, implant-supported crowns, and fixed dental prostheses.

    Teichmann, Maren; Göckler, Fabian; Weber, Volker; Yildirim, Murat; Wolfart, Stefan; Edelhoff, Daniel

    2017-01-01

    To prospectively evaluate the clinical long-term outcome of tooth-supported crowns (SCs), implant-supported crowns (ISCs), and fixed dental prostheses (FDPs) made of a lithium-disilicate glass-ceramic framework material (IPS Empress 2). Between 1997 and 1999, a total of 184 restorations (106 SCs, 32 ISCs, 33 FDPs, and 13 diverse restorations) were placed in 73 patients. Kaplan-Meier estimation was applied for survival and chipping-free rates. Inter-group comparison of both rates was realized by a log rank test and a 2×2 contingency table. Also, SCs and FDPs were compared regarding adhesive vs. conventional cementation, and anterior vs. posterior positioning, for impact on survival. Due to 14 dropouts (34 restorations) and reasonable exclusion of 19 other restorations, the final dataset included: i) 87 SCs [37 patients, mean observation time 11.4 (±3.8)years]; ii) 17 ISCs [12 patients, mean observation time 13.3 (±2.3)years; and iii) 27 FDPs [19 patients, mean observation time 8.9 (±5.4)years]. The 10-year survival rate/chipping-free rate for SCs were 86.1%/83.4%, for ISCs 93.8%/94.1%, and for FDPs were 51.9%/90.8%. Both ISCs and SCs had a significantly higher survival than FDPs (ISCs vs. FDPs: both tests p=0.001; SCs vs. FDPs: p=0.001 and p=0.005). Differences in the chipping-free rates did not reach significance. Also, neither the cementation mode nor positioning of the restoration had an impact on survival. SCs had a slightly lower outcome than can generally be expected from single crowns. In contrast, ICSs had a favorable outcome and the FDPs predominantly failed. The practitioner's choice of dental materials is based (at best) on long-term experience. The present 10-year results are based on comprehensive data analyses and show the high potential of lithium-disilicate as a reliable material, especially for single-unit restoration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Critical flashing flows in nozzles with subcooled inlet conditions

    Abuaf, N.; Jones, O.C. Jr.; Wu, B.J.C.

    1983-01-01

    Examination of a large number of experiments dealing with flashing flows in converging and converging-diverging nozzles reveals that knowledge of the flashing inception point is the key to the prediction of critical flow rates. An extension of the static flashing inception correlation of Jones [16] and Alamgir and Lienhard [17] to flowing systems has allowed the determination of the location of flashing inception in nozzle flows with subcooled inlet conditions. It is shown that in all the experiments examined with subcooled inlet regardless of the degree of inlet subcooling, flashing inception invariably occurred very close to the throat. A correlation is given to predict flashing inception in both pipes and nozzles which matches all data available, but is lacking verification in intermediate nozzle geometries where turbulence may be important. A consequence of this behavior is that the critical mass flux may be correlated to the pressure difference between the nozzle inlet and flashing inception, through a single phase liquid discharge coefficient and an accurate prediction of the flashing inception pressure at the throat. Comparison with the available experiments indicate that the predicted mass fluxes are within 5 percent of the measurements

  20. Unsteady flow characteristic analysis of turbine based combined cycle (TBCC inlet mode transition

    Jun Liu

    2015-09-01

    Full Text Available A turbine based combined cycle (TBCC propulsion system uses a turbine-based engine to accelerate the vehicle from takeoff to the mode transition flight condition, at which point, the propulsion system performs a “mode transition” from the turbine to ramjet engine. Smooth inlet mode transition is accomplished when flow is diverted from one flowpath to the other, without experiencing unstart or buzz. The smooth inlet mode transition is a complex unsteady process and it is one of the enabling technologies for combined cycle engine to become a functional reality. In order to unveil the unsteady process of inlet mode transition, the research of over/under TBCC inlet mode transition was conducted through a numerical simulation. It shows that during the mode transition the terminal shock oscillates in the inlet. During the process of inlet mode transition mass flow rate and Mach number of turbojet flowpath reduce with oscillation. While in ramjet flowpath the flow field is non-uniform at the beginning of inlet mode transition. The speed of mode transition and the operation states of the turbojet and ramjet engines will affect the motion of terminal shock. The result obtained in present paper can help us realize the unsteady flow characteristic during the mode transition and provide some suggestions for TBCC inlet mode transition based on the smooth transition of thrust.

  1. Silicon Microleaks for Inlets of Mass Spectrometers

    Harpold, Dan; Hasso, Niemann; Jamieson, Brian G.; Lynch, Bernard A.

    2009-01-01

    Microleaks for inlets of mass spectrometers used to analyze atmospheric gases can be fabricated in silicon wafers by means of photolithography, etching, and other techniques that are commonly used in the manufacture of integrated circuits and microelectromechanical systems. The microleaks serve to limit the flows of the gases into the mass-spectrometer vacuums to specified very small flow rates consistent with the capacities of the spectrometer vacuum pumps. There is a need to be able to precisely tailor the dimensions of each microleak so as to tailor its conductance to a precise low value. (As used here, "conductance" signifies the ratio between the rate of flow in the leak and the pressure drop from the upstream to the downstream end of the leak.) To date, microleaks have been made, variously, of crimped metal tubes, pulled glass tubes, or frits. Crimped-metal and pulled-glass-tube microleaks cannot readily be fabricated repeatably to precise dimensions and are susceptible to clogging with droplets or particles. Frits tend to be differentially chemically reactive with various gas constituents and, hence, to distort the gas mixtures to be analyzed. The present approach involving microfabrication in silicon largely overcomes the disadvantages of the prior approaches.

  2. Can barrier islands survive sea level rise? Tidal inlets versus storm overwash

    Nienhuis, J.; Lorenzo-Trueba, J.

    2017-12-01

    Barrier island response to sea level rise depends on their ability to transgress and move sediment to the back barrier, either through flood-tidal delta deposition or via storm overwash. Our understanding of these processes over decadal to centennial timescales, however, is limited and poorly constrained. We have developed a new barrier inlet environment (BRIE) model to better understand the interplay between tidal dynamics, overwash fluxes, and sea-level rise on barrier evolution. The BRIE model combines existing overwash and shoreface formulations [Lorenzo-Trueba and Ashton, 2014] with alongshore sediment transport, inlet stability [Escoffier, 1940], inlet migration and flood-tidal delta deposition [Nienhuis and Ashton, 2016]. Within BRIE, inlets can open, close, migrate, merge with other inlets, and build flood-tidal delta deposits. The model accounts for feedbacks between overwash and inlets through their mutual dependence on barrier geometry. Model results suggest that when flood-tidal delta deposition is sufficiently large, barriers require less storm overwash to transgress and aggrade during sea level rise. In particular in micro-tidal environments with asymmetric wave climates and high alongshore sediment transport, tidal inlets are effective in depositing flood-tidal deltas and constitute the majority of the transgressive sediment flux. Additionally, we show that artificial inlet stabilization (via jetty construction or maintenance dredging) can make barrier islands more vulnerable to sea level rise. Escoffier, F. F. (1940), The Stability of Tidal Inlets, Shore and Beach, 8(4), 114-115. Lorenzo-Trueba, J., and A. D. Ashton (2014), Rollover, drowning, and discontinuous retreat: Distinct modes of barrier response to sea-level rise arising from a simple morphodynamic model, J. Geophys. Res. Earth Surf., 119(4), 779-801, doi:10.1002/2013JF002941. Nienhuis, J. H., and A. D. Ashton (2016), Mechanics and rates of tidal inlet migration: Modeling and application to

  3. New piezo driven gas inlet valve for fusion experiments

    Usselmann, E.; Hemmerich, J.L.; How, J.; Holland, D.; Orchard, J.; Winkel, T.; Schargitz, U.; Pocheim, N.

    1989-01-01

    The gas inlet valves used at the JET experiment are described and their performances are discussed. A new gas-valve development suitable to replace the existing valves at JET and for future use in large fusion experiments is presented. The new valve is equipped with a piezo-electric translator and has a dosing range of 0-800 mbarls -1 for D 2 . The operating mode of the valve is fail-safe closed with a leak-rate of ≤ 10 -9 mbarls -1 . The design, the test results and throughput values in dependence of filling pressure and control voltage are presented and experiences with the prototype valve as a new gas inlet valve for the JET operation are described

  4. Influence of temperament score and handling facility on stress, reproductive hormone concentrations, and fixed time AI pregnancy rates in beef heifers.

    Kasimanickam, R; Schroeder, S; Assay, M; Kasimanickam, V; Moore, D A; Gay, J M; Whittier, W D

    2014-10-01

    The objectives were (i) to evaluate the effect of temperament, determined by modified 2-point chute exit and gait score, on artificial insemination (AI) pregnancy rates in beef heifers following fixed time AI and (ii) to determine the effect of temperament on cortisol, substance-P, prolactin and progesterone at initiation of synchronization and at the time of AI. Angus beef heifers (n = 967) at eight locations were included in this study. At the initiation of synchronization (Day 0 = initiation of synchronization), all heifers received a body condition score (BCS), and temperament score (0 = calm; slow exit and walk or 1 = excitable; fast exit or jump or trot or run). Blood samples were collected from a sub-population of heifers (n = 86) at both synchronization initiation and the time of AI to determine the differences in serum progesterone, cortisol, prolactin and substance-P concentrations between temperament groups. Heifers were synchronized with 5-day CO-Synch+ controlled internal drug release (CIDR) protocol and were inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy by ultrasound 70 days after AI to determine AI pregnancy. Controlling for synchronization treatment (p = 0.03), facility design (p = 0.05), and cattle handling facility design by temperament score interaction (p = 0.02), the AI pregnancy differed between heifers with excitable and calm temperament (51.9% vs 60.3%; p = 0.01). The alley-way with acute bends and turns, and long straight alley-way had lower AI pregnancy rate than did the semicircular alley-way (53.5%, 56.3% and 67.0% respectively; p = 0.05). The serum hormone concentrations differed significantly between different types of cattle handling facility (p < 0.05). The cattle handling facility design by temperament group interactions significantly influenced progesterone (p = 0.01), cortisol (p = 0.01), prolactin (p = 0.02) and substance-P (p = 0.04) both at the initiation of

  5. JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

    Jiří Pečinka

    2017-02-01

    Full Text Available Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion that might appear at the inlet of a gas turbine engine (GTE during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

  6. Empirical method to calculate Clinch River Breeder Reactor (CRBR) inlet plenum transient temperatures

    Howarth, W.L.

    1976-01-01

    Sodium flow enters the CRBR inlet plenum via three loops or inlets. An empirical equation was developed to calculate transient temperatures in the CRBR inlet plenum from known loop flows and temperatures. The constants in the empirical equation were derived from 1/4 scale Inlet Plenum Model tests using water as the test fluid. The sodium temperature distribution was simulated by an electrolyte. Step electrolyte transients at 100 percent model flow were used to calculate the equation constants. Step electrolyte runs at 50 percent and 10 percent flow confirmed that the constants were independent of flow. Also, a transient was tested which varied simultaneously flow rate and electrolyte. Agreement of the test results with the empirical equation results was good which verifies the empirical equation

  7. Effect of a dual inlet channel on cell loading in microfluidics.

    Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

    2014-11-01

    Unwanted sedimentation and attachment of a number of cells onto the bottom channel often occur on relatively large-scale inlets of conventional microfluidic channels as a result of gravity and fluid shear. Phenomena such as sedimentation have become recognized problems that can be overcome by performing microfluidic experiments properly, such as by calculating a meaningful output efficiency with respect to real input. Here, we present a dual-inlet design method for reducing cell loss at the inlet of channels by adding a new " upstream inlet " to a single main inlet design. The simple addition of an upstream inlet can create a vertically layered sheath flow prior to the main inlet for cell loading. The bottom layer flow plays a critical role in preventing the cells from attaching to the bottom of the channel entrance, resulting in a low possibility of cell sedimentation at the main channel entrance. To provide proof-of-concept validation, we applied our design to a microfabricated flow cytometer system (μFCS) and compared the cell counting efficiency of the proposed μFCS with that of the previous single-inlet μFCS and conventional FCS. We used human white blood cells and fluorescent microspheres to quantitatively evaluate the rate of cell sedimentation in the main inlet and to measure fluorescence sensitivity at the detection zone of the flow cytometer microchip. Generating a sheath flow as the bottom layer was meaningfully used to reduce the depth of field as well as the relative deviation of targets in the z-direction (compared to the x-y flow plane), leading to an increased counting sensitivity of fluorescent detection signals. Counting results using fluorescent microspheres showed both a 40% reduction in the rate of sedimentation and a 2-fold higher sensitivity in comparison with the single-inlet μFCS. The results of CD4(+) T-cell counting also showed that the proposed design results in a 25% decrease in the rate of cell sedimentation and a 28% increase in

  8. Coolant inlet device for nuclear reactors

    Ando, Hiroshi; Abe, Yasuhiro; Iwabuchi, Toshihiko; Yamamoto, Kenji.

    1969-01-01

    Herein disclosed is a coolant inlet device for liquid-metal cooled reactors which employs a coolant distributor serving also as a supporting means for the reactor core. The distributor is mounted within the reactor vessel so as to slide horizontally on supporting lugs, and is further slidably connected via a junction pipe to a coolant inlet conduit protruding through the floor of the vessel. The distributor is adapted to uniformly disperse the highly pressured coolant over the reactor core so as to reduce the stresses sustained by the reactor vessel as well as the supporting lugs. Moreover, the slidable nature of the distributor allows thermal shock and excessive coolant pressures to be prevented or alleviated, factors which posed major difficulties in conventional coolant inlet devices. (Owens, K. J.)

  9. Development of a solenoid actuated planar valveless micropump with single and multiple inlet-outlet arrangements

    Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.

    2016-07-01

    We report a planar solenoid actuated valveless micropump with multiple inlet-outlet configurations. The self-priming characteristics of the multiple inlet-multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet-multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet-two outlet micropump provides a maximum flow rate of 336 μl min-1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet-two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.

  10. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Han, Feng Hui; Mao, Yi Jun; Tan, Ji Jian

    2016-01-01

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets

  11. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Han, Feng Hui; Mao, Yi Jun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an (China); Tan, Ji Jian [Dept. of Research and Development, Shenyang Blower Works Group Co., Ltd., Shenyang (China)

    2016-11-15

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets.

  12. Cold water inlet in solar tanks - valuation

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the rat...

  13. CFD analysis of flow distribution at the core inlet of SMART

    Bae, Youngmin, E-mail: ybae@kaeri.re.kr [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Young In; Park, Cheon Tae [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2013-05-15

    Highlights: ► Core inlet flow distribution of system-integrated modular advanced reactor (SMART) is numerically investigated. ► Effects of mesh resolution, turbulence model, Reynolds number, and inflow condition are examined. ► Numerical results show that lower core support plate effectively distributes the flow at the core inlet of SMART. -- Abstract: This study numerically investigates the flow distribution at the core inlet region of the system-integrated modular advanced reactor (SMART). The single-phase turbulent flow is computed by the commercial CFD code, Fluent 12.0 on the computational domain consisting of three main parts: fuel assemblies, a lower core support plate, and a flow skirt. Simulations are carried out with different mesh resolutions, turbulence models, and upstream boundary conditions. The CFD results show that the flow distribution at the core inlet is almost identical for the two Reynolds numbers and turbulence models tested here, and the effect of mesh refinement on the flow distribution at the core inlet is negligible. It is also found that under a uniform upstream boundary condition, the maximum difference in mass flow rate between the fuel assemblies is less than 2%, while it slightly increases to 2.3% under a non-uniform condition. These results consequently indicate that the present design of the lower core support plate effectively distributes the flow at the core inlet of SMART, even when the flow discharged from the upstream has a certain degree of non-uniformity.

  14. Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.

    Yan Yang

    Full Text Available A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions.

  15. Inlet-engine matching for SCAR including application of a bicone variable geometry inlet

    Wasserbauer, J. F.; Gerstenmaier, W. H.

    1978-01-01

    Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined, where the second cone of a two cone center body collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

  16. A Tale of Two Inlets: Tidal Currents at Two Adjacent Inlets in the Indian River Lagoon

    Webb, B. M.; Weaver, R. J.

    2012-12-01

    The tidal currents and hydrography at two adjacent inlets of the Indian River Lagoon estuary (Florida) were recently measured using a personal watercraft-based coastal profiling system. Although the two inlets—Sebastian Inlet and Port Canaveral Inlet—are separated by only 60 km, their characteristics and dynamics are quite unique. While Sebastian Inlet is a shallow (~4 m), curved inlet with a free connection to the estuary, Port Canaveral Inlet is dominated by a deep (~13 m), straight ship channel and has limited connectivity to the Banana River through a sector gate lock. Underway measurements of tidal currents were obtained using a bottom tracking acoustic Doppler current profiler; vertical casts of hydrography were obtained with a conductivity-temperature-depth profiling instrument; and continuous underway measurements of surface water hydrography were made using a Portable SeaKeeper system. Survey transects were performed to elucidate the along-channel variability of tidal flows, which appears to be significant in the presence of channel curvature. Ebb and flood tidal currents in Sebastian Inlet routinely exceeded 2.5 m/s from the surface to the bed, and an appreciable phase lag exists between tidal stage and current magnitude. The tidal currents at Port Canaveral Inlet were much smaller (~0.2 m/s) and appeared to be sensitive to meteorological forcing during the study period. Although the lagoon has free connections to the ocean 145 km to the north and 45 km to the south, Sebastian Inlet likely drains much of the lagoon to its north, an area of ~550 sq. km.

  17. Adsorption of ciprofloxacin and norfloxacin from aqueous solution onto granular activated carbon in fixed bed column.

    Darweesh, Teeba M; Ahmed, Muthanna J

    2017-04-01

    Carbonization of Phoenix dactylifera L stones followed by microwave K 2 CO 3 activation was adopted for preparation of granular activated carbon (KAC). High yield and favorable pore characteristics in terms of surface area and pore volume were reported for KAC as follows: 44%, 852m 2 /g, and 0.671cm 3 /g, respectively. The application of KAC as adsorbent for attraction of ciprofloxacin (CIP) and norfloxacin (NOR) was investigated using fixed bed systems. The effect of flow rate (0.5-1.5ml/min), bed height (15-25cm), and initial drug concentration (75-225mg/l) on the behavior of breakthrough curves was explained. The fixed bed analysis showed the better correlation of breakthrough data by both Thomas and Yoon-Nelson models. Inlet drug concentration was of greatest effect on breakthrough data compared to other fixed bed variables. Experimental and calculated breakthrough data were obtained for CIP and NOR adsorption on KAC, thus being important for design of fixed bed column. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Experimental Investigation of Inlet Distortion in a Multistage Axial Compressor

    Rusu, Razvan

    The primary objective of this research is to present results and methodologies used to study total pressure inlet distortion in a multi-stage axial compressor environment. The study was performed at the Purdue 3-Stage Axial Compressor Facility (P3S) which models the final three stages of a production turbofan engine's high-pressure compressor (HPC). The goal of this study was twofold; first, to design, implement, and validate a circumferentially traversable total pressure inlet distortion generation system, and second, to demonstrate data acquisition methods to characterize the inter-stage total pressure flow fields to study the propagation and attenuation of a one-per-rev total pressure distortion. The datasets acquired for this study are intended to support the development and validation of novel computational tools and flow physics models for turbomachinery flow analysis. Total pressure inlet distortion was generated using a series of low-porosity wire gauze screens placed upstream of the compressor in the inlet duct. The screens are mounted to a rotatable duct section that can be precisely controlled. The P3S compressor features fixed instrumentation stations located at the aerodynamic interface plane (AIP) and downstream and upstream of each vane row. Furthermore, the compressor features individually indexable stator vanes which can be traverse by up to two vane passages. Using a series of coordinated distortion and vane traverses, the total pressure flow field at the AIP and subsequent inter-stage stations was characterized with a high circumferential resolution. The uniformity of the honeycomb carrier was demonstrated by characterizing the flow field at the AIP while no distortion screens where installed. Next, the distortion screen used for this study was selected following three iterations of porosity reduction. The selected screen consisted of a series of layered screens with a 100% radial extent and a 120° circumferential extent. A detailed total

  19. Flow Control in a Compact Inlet

    Vaccaro, John C.

    2011-12-01

    An experimental investigation of flow control, via various control jets actuators, was undertaken to eliminate separation and secondary flows in a compact inlet. The compact inlet studied was highly aggressive with a length-to-diameter ratio of 1.5. A brand new facility was designed and built to enable various actuation methodologies as well as multiple measurement techniques. Techniques included static surface pressure, total pressure, and stereoscopic particle image velocimetry. Experimental data were supplemented with numerical simulations courtesy of Prof. Kenneth Jansen, Dr. Onkar Sahni, and Yi Chen. The baseline flow field was found to be dominated by two massive separations and secondary flow structures. These secondary structures were present at the aerodynamic interface plane in the form of two counter-rotating vortices inducing upwash along centerline. A dominant shedding frequency of 350 Hz was measured both at the aerodynamic interface plane and along the lower surface of the inlet. Flow control experiments started utilizing a pair of control jets placed in streamwise locations where flow was found to separate. Tests were performed for a range of inlet Mach numbers from 0.2 to 0.44. Steady and unsteady static pressure measurements along the upper and lower walls of the duct were performed for various combinations of actuation. The parameters that were tested include the control jets momentum coefficient, their blowing ratio, the actuation frequency, as well as different combinations of jets. It was shown that using mass flux ratio as a criterion to define flow control is not sufficient, and one needs to provide both the momentum coefficient and the blowing ratio to quantify the flow control performance. A detailed study was undertaken on controlling the upstream separation point for an inlet Mach number of 0.44. Similar to the baseline flow field, the flow field associated with the activation of a two-dimensional control jet actuator was dominated by

  20. Fixed-bed column studies of total organic carbon removal from industrial wastewater by use of diatomite decorated with polyethylenimine-functionalized pyroxene nanoparticles.

    Hethnawi, Afif; Manasrah, Abdallah D; Vitale, Gerardo; Nassar, Nashaat N

    2018-03-01

    In this study, a fixed-bed column adsorption process was employed to remove organic pollutants from a real industrial wastewater effluent using polyethylenimine-functionalized pyroxene nanoparticles (PEI-PY) embedded into Diatomite at very low mass percentage. Various dynamic parameters (e.g., inlet concentration, inlet flow rate, bed height, and PEI-nanoparticle concentration in Diatomite, (%nps)) were investigated to determine the breakthrough behavior. The obtained breakthrough curves were fit with a convection-dispersion model to determine the characteristic parameters based on mass transfer phenomena. The axial dispersion coefficient (D L ) and group of dimensionless numbers; including Renold number (Re), Schmidt number (Sc), and Sherwood number (Sh) were all determined and correlated by Wilson-Geankoplis correlation that was used to estimate the external film diffusion coefficients (Kc) at 0.0015 < Re<55. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Performance of the University of Denver Low Turbulence, Airborne Aerosol Inlet in ACE-Asia

    Lafleur, B.; Wilson, J. C.; Seebaugh, W. R.; Gesler, D.; Hilbert, H.; Mullen, J.; Reeves, J. M.

    2002-12-01

    The University of Denver Low Turbulence Inlet (DULTI) was flown on the NCAR C-130 in ACE-Asia. This inlet delivered large sample flows at velocities of a few meters per second at the exit of the inlet. This flow was slowed from the true air speed of the aircraft (100 to 150 m/s) to a few meters per second in a short diffuser with porous walls. The flow in the diffusing section was laminar. The automatic control system kept the inlet operating at near isokinetic intake velocities and in laminar flow for nearly all the flight time. The DULTI permits super micron particles to be sampled and delivered with high efficiency to the interior of the aircraft where they can be measured or collected. Because most of the air entering the inlet is removed through the porous medium, the sample flow experiences inertial enhancements. Because these enhancements occur in laminar flow, they are calculable using FLUENT. Enhancement factors are defined as the ratio of the number of particles of a given size per unit mass of air in the sample to the number of particles of that size per unit mass of air in the ambient. Experimenters divide measured mixing ratios of the aerosol by the enhancement factor to get the ambient mixing ratio of the particles. The diffuser used in ACE-Asia differed from that used in PELTI (2000), TexAQS2000 (2000) and ITCT (2002). In this poster, the flow parameters measured in the inlet in flight are compared with those calculated from FLUENT. And enhancement factors are presented for flight conditions. The enhancement factors are found to depend upon the Stokes number of particles in the entrance to the inlet and the ratio of the mass flow rate of air removed by suction to the mass flow rate delivered as sample.

  2. Variable geometry for supersonic mixed-compression inlets

    Sorensen, N. E.; Latham, E. A.; Smeltzer, D. B.

    1974-01-01

    Study of two-dimensional and axisymmetric supersonic mixed-compression inlet systems has shown that the geometry of both systems can be varied to provide adequate transonic airflow to satisfy the airflow demand of most jet engines. Collapsing geometry systems for both types of inlet systems provide a generous amount of transonic airflow for any design Mach number inlet system. However, the mechanical practicality of collapsing centerbodies for axisymmetric inlet systems is doubtful. Therefore, translating centerbody axisymmetric inlets with auxiliary airflow systems to augment the transonic airflow capability are an attractive alternative. Estimates show that the capture mass-flow ratio at Mach number 1.0 can be increased approximately 0.20 for a very short axisymmetric inlet system designed for Mach number 2.37. With this increase in mass-flow ratio, even variable-cycle engine transonic airflow demand can be matched without oversizing the inlet at the design Mach number.

  3. Unstart coupling mechanism analysis of multiple-modules hypersonic inlet.

    Hu, Jichao; Chang, Juntao; Wang, Lei; Cao, Shibin; Bao, Wen

    2013-01-01

    The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  4. Two-Dimensional Bifurcated Inlet Variable Cowl Lip Test Completed in 10- by 10-Foot Supersonic Wind Tunnel

    Hoffman, T. R.

    2000-01-01

    Researchers at the NASA Glenn Research Center at Lewis Field successfully tested a variable cowl lip inlet at simulated takeoff conditions in Glenn s 10- by 10-Foot Supersonic Wind Tunnel (10x10 SWT) as part of the High-Speed Research Program. The test was a follow-on to the Two-Dimensional Bifurcated (2DB) Inlet/Engine test. At the takeoff condition for a High-Speed Civil Transport aircraft, the inlet must provide adequate airflow to the engine with an acceptable distortion level and high-pressure recovery. The test was conducted to study the effectiveness of installing two rotating lips on the 2DB Inlet cowls to increase mass flow rate and eliminate or reduce boundary layer flow separation near the lips. Hardware was mounted vertically in the test section so that it extended through the tunnel ceiling and that the 2DB Inlet was exposed to the atmosphere above the test section. The tunnel was configured in the aerodynamic mode, and exhausters were used to pump down the tunnel to vacuum levels and to provide a maximum flow rate of approximately 58 lb/sec. The test determined the (1) maximum flow in the 2DB Inlet for each variable cowl lip, (2) distortion level and pressure recovery for each lip configuration, (3) boundary layer conditions near variable lips inside the 2DB Inlet, (4) effects of a wing structure adjacent to the 2DB Inlet, and (5) effects of different 2DB Inlet exit configurations. It also employed flow visualization to generate enough qualitative data on variable lips to optimize the variable lip concept. This test was a collaborative effort between the Boeing Company and Glenn. Extensive inhouse support at Glenn contributed significantly to the progress and accomplishment of this test.

  5. Failure of the Nernst-Einstein equation to correlate electrical resistances and rates of ionic self-exchange across certain fixed charge membranes.

    Gottlieb, M H; Sollner, K

    1968-05-01

    The electrical resistances and rates of self-exchange of univalent critical ions across several types of collodion matrix membranes of high ionic selectivity were studied over a wide range of conditions. The relationship which was observed between these quantities with membranes of a certain type, namely those activated with poly-2-vinyl-N-methyl pyridinium bromide, cannot be explained on the basis of current concepts of the movement of ions across ion exchange membranes. Rates of self-exchange across these membranes were several times greater than those calculated from the electrical resistances of the membranes on the basis of an expression derived by the use of the Nernst-Einstein equation. The magnitude of the discrepancy was greatest at low concentrations of the ambient electrolyte solution and was independent of the species of both critical and noncritical ions. The data obtained with other types of collodion matrix membranes were, at least approximately, in agreement with the predictions based on the Nernst-Einstein equation. Self-exchange rates across the anion permeable protamine collodion membranes, and across the cation permeable polystyrene sulfonic acid collodion membranes, were about 20% less than those calculated from the electrical resistances. The direction and magnitude of these differences, also observed by other investigators, are qualitatively understood as an electroosmotic effect. With cation permeable membranes prepared by the oxidation of preformed collodion membranes, almost exact agreement was obtained between measured and calculated self-exchange rates; the cause of the apparent absence of an electroosmotic effect with these membranes is unknown.

  6. What Drives Bank Lending in Domestic and Foreign Currency Loans in a Small Open Transition Economy with Fixed Exchange Rate? The Case of Macedonia

    Jane Bogoev

    2011-01-01

    This paper investigates two different bank loan supply functions and their determinants according to the currency of bank loans in the Republic of Macedonia. There is robust statistical evidence in favour of the existence of a bank lending channel through foreign currency loans and the foreign reference interest rate. This suggests that the impact of domestic monetary policy over the bank lending channel is limited. The most significant bank-specific characteristic for the foreign currency lo...

  7. A Phase I-II dose escalation study of fixed-dose rate gemcitabine, oxaliplatin and capecitabine every two weeks in advanced cholangiocarcinomas

    Lassen, Ulrik V; Jensen, Lars Henrik; Sorensen, Morten

    2011-01-01

    (O) and capecitabine (C), and evaluate the safety and efficacy of this regimen in patients with advanced cholangiocarcinoma (CC). Methods. In the Phase I part of the study a dose-escalation schedule of FDR G, O and C, administered every two weeks, was performed in patients with solid tumours...... and no other treatments or advanced CC. In the Phase II part response rate, toxicity, progression-free survival (PFS) and overall survival was evaluated in patients with newly diagnosed advanced CC. Results. Thirty-six patients entered the Phase I part and G 1 000 mg/m(2) day 1 and 15, O 60 mg/m(2) day 1...... and 15, and C 1 000 mg/m(2) BID day 1-7 and day 15-21 were established as MTD. In the Phase II part, 41 patients with advanced CC were included. Overall response rate was 34% and 51% had stable disease, resulting in a clinical benefit rate of 85%. Grade III and IV adverse events were rare. Median...

  8. Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles

    Maqsood, Omar Shahzada

    Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

  9. Fixed Costs and Hours Constraints

    Johnson, William R.

    2011-01-01

    Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

  10. 40 CFR 53.63 - Test procedure: Wind tunnel inlet aspiration test.

    2010-07-01

    ... the sampler inlet opening centered in the sampling zone. To meet the maximum blockage limit of § 53.62(c)(1) or for convenience, part of the test sampler may be positioned external to the wind tunnel... = reference method sampler volumetric flow rate; and t = sampling time. (iii) Remove the reference method...

  11. Effects of inlet/outlet configurations on the electrostatic capture of airborne nanoparticles and viruses

    Jang, Jaesung; Akin, Demir; Bashir, Rashid

    2008-01-01

    Motivated by capture and detection of airborne biological agents in real time with a cantilever biosensor without introducing the agents into liquids, we present the effects of inlet/outlet configurations of a homemade particle collector on the electrostatic capture of airborne 100 nm diameter nanoparticles under swirling gas flows. This particle collector has three different inlet/outlet configurations: forward inlet/outlet (FO), backward inlet/outlet (BO) and straight inlet/outlet (SO) configurations. We also present the electrostatic capture of Vaccinia viruses using the same particle collector and compare these virus measurements with the nanoparticle cases. The most particles were collected in the FO configuration. The numbers of particles captured in the BO and SO configurations were close within their standard deviations. For all the three configurations tested, the number of particles captured in the center electrode C was much smaller than those captured in the other electrodes at a flow rate of 1.1 l min −1 and an applied potential of 2 kV. Using a commercial CFD code FLUENT, we also simulated the effects of the three inlet/outlet configurations on the particle capture in terms of particle trajectories, velocities and travel times. This simulation was in a good agreement with measurements that the FO configuration is the most favorable to particle capture among the tested configurations at a flow rate of 1.1 l min −1 . The effects of particle diameters on the capture will also be discussed. This collector can be used for real-time monitoring of bioaerosols along with cantilever biosensors

  12. Apparatus for fixing radioactive waste

    Murphy, J.D.; Pirro, J. Jr.; Lawrence, M.; Wisla, S.F.

    1975-01-01

    Fixing radioactive waste is disclosed in which the waste is collected as a slurry in aqueous media in a metering tank located within the nuclear facilities. Collection of waste is continued from time to time until a sufficient quantity of material to make up a full shipment to a burial ground has been collected. The slurry is then cast in shipping containers for shipment to a burial ground or the like by metering through a mixer into which fixing materials are simultaneously metered at a rate to yield the desired proportions of materials. (U.S.)

  13. Geometry of tidal inlet systems : A key factor for the net sediment transport in tidal inlets

    Ridderinkhof, W.; de Swart, H. E.; van der Vegt, M.; Alebregtse, N. C.; Hoekstra, P.

    2014-01-01

    The net transport of sediment between the back-barrier basin and the sea is an important process for determining the stability of tidal inlet systems. Earlier studies showed that in a short basin, tidal flats favor peak ebb-currents stronger than peak flood currents, implying export of coarse

  14. Mercury in Sediment, Water, and Biota of Sinclair Inlet, Puget Sound, Washington, 1989-2007

    Paulson, Anthony J.; Keys, Morgan E.; Scholting, Kelly L.

    2010-01-01

    Historical records of mercury contamination in dated sediment cores from Sinclair Inlet are coincidental with activities at the U.S. Navy Puget Sound Naval Shipyard; peak total mercury concentrations occurred around World War II. After World War II, better metallurgical management practices and environmental regulations reduced mercury contamination, but total mercury concentrations in surface sediment of Sinclair Inlet have decreased slowly because of the low rate of sedimentation relative to the vertical mixing within sediment. The slopes of linear regressions between the total mercury and total organic carbon concentrations of sediment offshore of Puget Sound urban areas was the best indicator of general mercury contamination above pre-industrial levels. Prior to the 2000-01 remediation, this indicator placed Sinclair Inlet in the tier of estuaries with the highest level of mercury contamination, along with Bellingham Bay in northern Puget Sound and Elliott Bay near Seattle. This indicator also suggests that the 2000/2001 remediation dredging had significant positive effect on Sinclair Inlet as a whole. In 2007, about 80 percent of the area of the Bremerton naval complex had sediment total mercury concentrations within about 0.5 milligrams per kilogram of the Sinclair Inlet regression. Three areas adjacent to the waterfront of the Bremerton naval complex have total mercury concentrations above this range and indicate a possible terrestrial source from waterfront areas of Bremerton naval complex. Total mercury concentrations in unfiltered Sinclair Inlet marine waters are about three times higher than those of central Puget Sound, but the small numbers of samples and complex physical and geochemical processes make it difficult to interpret the geographical distribution of mercury in marine waters from Sinclair Inlet. Total mercury concentrations in various biota species were compared among geographical locations and included data of composite samples, individual

  15. Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

    Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

    2016-01-01

    A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

  16. CFD Simulation of Dimethyl Ether Synthesis from Methanol in an Adiabatic Fixed-bed Reactor

    Mohammad Golshadi

    2013-04-01

    Full Text Available A computational fluid dynamic (CFD study of methanol (MeOH to dimethyl ether (DME process in an adiabatic fixed-bed reactor is presented. One of the methods of industrial DME production is the catalytic dehydration of MeOH. Kinetic model was derived based on Bercic rate. The parameters of this equation for a specific catalyst were tuned by solving a one-dimensional homogenous model using MATLAB optimization module. A two-dimensional CFD simulation of the reaction is demonstrated and considered as numerical experiments. A sensitivity analysis was run in order to find the effect of temperature, pressure, and WHSV on the reactor performance. Good agreement was achieved between bench experimental data and the model. The results show that the maximum conversion of reaction (about 85.03% is obtained at WHSV=10 h-1 and T=563.15 K, whereas the inlet temperature has a greater effect on methanol conversion. Moreover, the effect of water in inlet feed on methanol conversion is quantitatively studied. It was concluded that the results obtained from CFD analysis give precise guidelines for further studies on the optimization of reactor performance.

  17. CFD Models of a Serpentine Inlet, Fan, and Nozzle

    Chima, R. V.; Arend, D. J.; Castner, R. S.; Slater, J. W.; Truax, P. P.

    2010-01-01

    Several computational fluid dynamics (CFD) codes were used to analyze the Versatile Integrated Inlet Propulsion Aerodynamics Rig (VIIPAR) located at NASA Glenn Research Center. The rig consists of a serpentine inlet, a rake assembly, inlet guide vanes, a 12-in. diameter tip-turbine driven fan stage, exit rakes or probes, and an exhaust nozzle with a translating centerbody. The analyses were done to develop computational capabilities for modeling inlet/fan interaction and to help interpret experimental data. Three-dimensional Reynolds averaged Navier-Stokes (RANS) calculations of the fan stage were used to predict the operating line of the stage, the effects of leakage from the turbine stream, and the effects of inlet guide vane (IGV) setting angle. Coupled axisymmetric calculations of a bellmouth, fan, and nozzle were used to develop techniques for coupling codes together and to investigate possible effects of the nozzle on the fan. RANS calculations of the serpentine inlet were coupled to Euler calculations of the fan to investigate the complete inlet/fan system. Computed wall static pressures along the inlet centerline agreed reasonably well with experimental data but computed total pressures at the aerodynamic interface plane (AIP) showed significant differences from the data. Inlet distortion was shown to reduce the fan corrected flow and pressure ratio, and was not completely eliminated by passage through the fan

  18. Inlet-engine matching for SCAR including application of a bicone variable geometry inlet. [Supersonic Cruise Aircraft Research

    Wasserbauer, J. F.; Gerstenmaier, W. H.

    1978-01-01

    Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined where the second cone of a two cone centerbody collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

  19. Fuel rod fixing system

    Christiansen, D.W.

    1982-01-01

    This is a reusable system for fixing a nuclear reactor fuel rod to a support. An interlock cap is fixed to the fuel rod and an interlock strip is fixed to the support. The interlock cap has two opposed fingers, which are shaped so that a base is formed with a body part. The interlock strip has an extension, which is shaped so that this is rigidly fixed to the body part of the base. The fingers of the interlock cap are elastic in bending. To fix it, the interlock cap is pushed longitudinally on to the interlock strip, which causes the extension to bend the fingers open in order to engage with the body part of the base. To remove it, the procedure is reversed. (orig.) [de

  20. General Investigation of Tidal Inlets: Stability of Selected United States Tidal Inlets

    1991-09-01

    characteristics in relation to the variability of the hydr; aulic parameters. An inlet can fall into any of four "stability" classes 48 Orientation Parameter 80...nlot he ~ :Ke(: t 93. If a fairly straight coast with uniform offshore slopes and a regionally homogeneous wave climate is considered, a reasonable...expectation is LhaL the longshore transport quantities and directions are homogeneous. Given a long-term variability in wave climate , a corresponding

  1. Boundary conditions for free surface inlet and outlet problems

    Taroni, M.; Breward, C. J. W.; Howell, P. D.; Oliver, J. M.

    2012-01-01

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown

  2. Seasonal behaviour of tidal inlets in a tropical monsoon area

    Lam, N.T.; Stive, M.J.F.; Verhagen, H.J.; Wang, Z.B.

    2008-01-01

    Morphodynamics of a tidal inlet system on a micro-tidal coast in a tropical monsoon influenced region is modelled and discussed. Influences of river flow and wave climate on the inlet morphology are investigated with the aid of process-based state-of-the-art numerical models. Seasonal and episodic

  3. Long time durability tests of fabric inlet stratification pipes

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    and that this destroys the capability of building up thermal stratification for the fabric inlet stratification pipe. The results also show that although dirt, algae etc. are deposited in the fabric pipes in the space heating tank, the capability of the fabric inlet stratifiers to build up thermal stratification...

  4. The price of fixed income market volatility

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  5. Observation and modeling of the evolution of an ephemeral storm-induced inlet: Pea Island Breach, North Carolina, USA

    Velasquez Montoya, Liliana; Sciaudone, Elizabeth J.; Mitasova, Helena; Overton, Margery F.

    2018-03-01

    The Outer Banks of North Carolina is a wave-dominated barrier island system that has experienced the opening and closure of numerous inlets in the last four centuries. The most recent of those inlets formed after the breaching of Pea Island during Hurricane Irene in 2011. The Pea Island Breach experienced a rapid evolution including episodic curvature of the main channel, rotation of the ebb channel, shoaling, widening by Hurricane Sandy in 2012, and finally closing before the summer of 2013. Studying the life cycle of Pea Island Breach contributes to understanding the behavior of ephemeral inlets in breaching-prone regions. This topic has gained relevance due to rising sea levels, a phenomenon that increases the chances of ephemeral inlet formation during extreme events. This study explores the spatiotemporal effects of tides, waves, and storms on flow velocities and morphology of the breach by means of remotely sensed data, geospatial metrics, and a numerical model. The combined use of observations and results from modeling experiments allowed building a conceptual model to explain the life cycle of Pea Island Breach. Wave seasonality dominated the morphological evolution of the inlet by controlling the magnitude and direction of the longshore current that continuously built transient spits at both sides of the breach. Sensitivity analysis to external forcings indicates that ocean waves can modify water levels and velocities in the back barrier. Sound-side storm surge regulates overall growth rate, duration, and decay of peak water levels entering the inlet during extreme events.

  6. Computational Fluid Dynamics (CFD) Simulation of Hypersonic Turbine-Based Combined-Cycle (TBCC) Inlet Mode Transition

    Slater, John W.; Saunders, John D.

    2010-01-01

    Methods of computational fluid dynamics were applied to simulate the aerodynamics within the turbine flowpath of a turbine-based combined-cycle propulsion system during inlet mode transition at Mach 4. Inlet mode transition involved the rotation of a splitter cowl to close the turbine flowpath to allow the full operation of a parallel dual-mode ramjet/scramjet flowpath. Steady-state simulations were performed at splitter cowl positions of 0deg, -2deg, -4deg, and -5.7deg, at which the turbine flowpath was closed half way. The simulations satisfied one objective of providing a greater understanding of the flow during inlet mode transition. Comparisons of the simulation results with wind-tunnel test data addressed another objective of assessing the applicability of the simulation methods for simulating inlet mode transition. The simulations showed that inlet mode transition could occur in a stable manner and that accurate modeling of the interactions among the shock waves, boundary layers, and porous bleed regions was critical for evaluating the inlet static and total pressures, bleed flow rates, and bleed plenum pressures. The simulations compared well with some of the wind-tunnel data, but uncertainties in both the windtunnel data and simulations prevented a formal evaluation of the accuracy of the simulation methods.

  7. Complex nonlinear behaviour of a fixed bed reactor with reactant recycle

    Recke, Bodil; Jørgensen, Sten Bay

    1999-01-01

    The fixed bed reactor with reactant recycle investigated in this paper can exhibit periodic solutions. These solutions bifurcate from the steady state in a Hopf bifurcation. The Hopf bifurcation encountered at the lowest value of the inlet concentration turns the steady state unstable and marks......,that the dynamic behaviour of a fixed bed reactor with reactant recycle is much more complex than previously reported....

  8. Rocket Based Combined Cycle Exchange Inlet Performance Estimation at Supersonic Speeds

    Murzionak, Aliaksandr

    A method to estimate the performance of an exchange inlet for a Rocket Based Combined Cycle engine is developed. This method is to be used for exchange inlet geometry optimization and as such should be able to predict properties that can be used in the design process within a reasonable amount of time to allow multiple configurations to be evaluated. The method is based on a curve fit of the shocks developed around the major components of the inlet using solutions for shocks around sharp cones and 2D estimations of the shocks around wedges with blunt leading edges. The total pressure drop across the estimated shocks as well as the mass flow rate through the exchange inlet are calculated. The estimations for a selected range of free-stream Mach numbers between 1.1 and 7 are compared against numerical finite volume method simulations which were performed using available commercial software (Ansys-CFX). The total pressure difference between the two methods is within 10% for the tested Mach numbers of 5 and below, while for the Mach 7 test case the difference is 30%. The mass flow rate on average differs by less than 5% for all tested cases with the maximum difference not exceeding 10%. The estimation method takes less than 3 seconds on 3.0 GHz single core processor to complete the calculations for a single flight condition as oppose to over 5 days on 8 cores at 2.4 GHz system while using 3D finite volume method simulation with 1.5 million elements mesh. This makes the estimation method suitable for the use with exchange inlet geometry optimization algorithm.

  9. Biofouling of inlet pipes affects water quality in running seawater aquaria and compromises sponge cell proliferation

    Brittany E. Alexander

    2015-12-01

    Full Text Available Marine organism are often kept, cultured, and experimented on in running seawater aquaria. However, surprisingly little attention is given to the nutrient composition of the water flowing through these systems, which is generally assumed to equal in situ conditions, but may change due to the presence of biofouling organisms. Significantly lower bacterial abundances and higher inorganic nitrogen species (nitrate, nitrite, and ammonium were measured in aquarium water when biofouling organisms were present within a 7-year old inlet pipe feeding a tropical reef running seawater aquaria system, compared with aquarium water fed by a new, biofouling-free inlet pipe. These water quality changes are indicative of the feeding activity and waste production of the suspension- and filter-feeding communities found in the old pipe, which included sponges, bivalves, barnacles, and ascidians. To illustrate the physiological consequences of these water quality changes on a model organism kept in the aquaria system, we investigated the influence of the presence and absence of the biofouling community on the functioning of the filter-feeding sponge Halisarca caerulea, by determining its choanocyte (filter cell proliferation rates. We found a 34% increase in choanocyte proliferation rates following the replacement of the inlet pipe (i.e., removal of the biofouling community. This indicates that the physiological functioning of the sponge was compromised due to suboptimal food conditions within the aquarium resulting from the presence of the biofouling organisms in the inlet pipe. This study has implications for the husbandry and performance of experiments with marine organisms in running seawater aquaria systems. Inlet pipes should be checked regularly, and replaced if necessary, in order to avoid excessive biofouling and to approach in situ water quality.

  10. Numerical Study on Shape of Liquid Inlet for Venturi Scrubber in Self-Priming Mode

    Lee, J. W.; Kim, H. S.; Kim, W. S. [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, the simulation was developed for different design of liquid inlet to improve injection in submerged self-priming mode venturi scrubber. 1. A hole type is easy to discharged gas from liquid inlet for submerged self-priming mode. 2. A spit type, the liquid is injected into venturi scrubber for all gas volume rate in submerged self-priming mode. 3. A spit type is better than a hole type on improving injection of liquid inlet for submerged self-priming mode in venturi scrubber.The gas accelerate in convergent segment and reach maximum velocity at throat. The liquid is injected into venturi scrubber depends on static pressure difference between outside and inside of the venturi throat, then liquid is atomized into fine droplet when it contacts with high speed airflow. Aerosol removal occur in the diverging section as the inlet gas stream mixes with the fog of tiny liquid droplets. Many studies dealing with the non-submerged selfpriming venturi scrubber. In a non-submerged condition, outlet nozzle of venturi scrubber is not immersed in water pool of a tank whereas in a submerged condition, the outlet of a venturi scrubber is immersed in water pool. The scrubbing liquid is supplied by water reservoir surrounding the throat and is drawn in due to a pressure difference between the outside and the inside of the venturi throat that arises out of the hydrostatic pressure of the liquid and static pressure of the flowing gas. The performance of a venturi scrubber is improved with high gas velocities and high liquid flow rate. Therefore, it is important to study the liquid fraction in venturi scrubber operated at different condition. The venturi scrubber is used to a submerged self-priming mode because the system operates in a passive mode in CFVS. The present study focuses on the liquid flow characteristics for various shapes of liquid inlet in submerged self-priming venturi scrubber.

  11. Numerical Study on Shape of Liquid Inlet for Venturi Scrubber in Self-Priming Mode

    Lee, J. W.; Kim, H. S.; Kim, W. S.

    2016-01-01

    In this study, the simulation was developed for different design of liquid inlet to improve injection in submerged self-priming mode venturi scrubber. 1. A hole type is easy to discharged gas from liquid inlet for submerged self-priming mode. 2. A spit type, the liquid is injected into venturi scrubber for all gas volume rate in submerged self-priming mode. 3. A spit type is better than a hole type on improving injection of liquid inlet for submerged self-priming mode in venturi scrubber.The gas accelerate in convergent segment and reach maximum velocity at throat. The liquid is injected into venturi scrubber depends on static pressure difference between outside and inside of the venturi throat, then liquid is atomized into fine droplet when it contacts with high speed airflow. Aerosol removal occur in the diverging section as the inlet gas stream mixes with the fog of tiny liquid droplets. Many studies dealing with the non-submerged selfpriming venturi scrubber. In a non-submerged condition, outlet nozzle of venturi scrubber is not immersed in water pool of a tank whereas in a submerged condition, the outlet of a venturi scrubber is immersed in water pool. The scrubbing liquid is supplied by water reservoir surrounding the throat and is drawn in due to a pressure difference between the outside and the inside of the venturi throat that arises out of the hydrostatic pressure of the liquid and static pressure of the flowing gas. The performance of a venturi scrubber is improved with high gas velocities and high liquid flow rate. Therefore, it is important to study the liquid fraction in venturi scrubber operated at different condition. The venturi scrubber is used to a submerged self-priming mode because the system operates in a passive mode in CFVS. The present study focuses on the liquid flow characteristics for various shapes of liquid inlet in submerged self-priming venturi scrubber.

  12. Biofouling of inlet pipes affects water quality in running seawater aquaria and compromises sponge cell proliferation.

    Alexander, Brittany E; Mueller, Benjamin; Vermeij, Mark J A; van der Geest, Harm H G; de Goeij, Jasper M

    2015-01-01

    Marine organism are often kept, cultured, and experimented on in running seawater aquaria. However, surprisingly little attention is given to the nutrient composition of the water flowing through these systems, which is generally assumed to equal in situ conditions, but may change due to the presence of biofouling organisms. Significantly lower bacterial abundances and higher inorganic nitrogen species (nitrate, nitrite, and ammonium) were measured in aquarium water when biofouling organisms were present within a 7-year old inlet pipe feeding a tropical reef running seawater aquaria system, compared with aquarium water fed by a new, biofouling-free inlet pipe. These water quality changes are indicative of the feeding activity and waste production of the suspension- and filter-feeding communities found in the old pipe, which included sponges, bivalves, barnacles, and ascidians. To illustrate the physiological consequences of these water quality changes on a model organism kept in the aquaria system, we investigated the influence of the presence and absence of the biofouling community on the functioning of the filter-feeding sponge Halisarca caerulea, by determining its choanocyte (filter cell) proliferation rates. We found a 34% increase in choanocyte proliferation rates following the replacement of the inlet pipe (i.e., removal of the biofouling community). This indicates that the physiological functioning of the sponge was compromised due to suboptimal food conditions within the aquarium resulting from the presence of the biofouling organisms in the inlet pipe. This study has implications for the husbandry and performance of experiments with marine organisms in running seawater aquaria systems. Inlet pipes should be checked regularly, and replaced if necessary, in order to avoid excessive biofouling and to approach in situ water quality.

  13. A phase I/II trial of intensity modulated radiation (IMRT) dose escalation with concurrent fixed-dose rate gemcitabine (FDR-G) in patients with unresectable pancreatic cancer.

    Ben-Josef, Edgar; Schipper, Mathew; Francis, Isaac R; Hadley, Scott; Ten-Haken, Randall; Lawrence, Theodore; Normolle, Daniel; Simeone, Diane M; Sonnenday, Christopher; Abrams, Ross; Leslie, William; Khan, Gazala; Zalupski, Mark M

    2012-12-01

    Local failure in unresectable pancreatic cancer may contribute to death. We hypothesized that intensification of local therapy would improve local control and survival. The objectives were to determine the maximum tolerated radiation dose delivered by intensity modulated radiation with fixed-dose rate gemcitabine (FDR-G), freedom from local progression (FFLP), and overall survival (OS). Eligibility included pathologic confirmation of adenocarcinoma, radiographically unresectable, performance status of 0-2, absolute neutrophil count of ≥ 1,500/mm(3), platelets ≥ 100,000/mm(3), creatinine CRM (Time-to-Event Continual Reassessment Method) with the target dose-limiting toxicity (DLT) rate set to 0.25. Fifty patients were accrued. DLTs were observed in 11 patients: G3/4 anorexia, nausea, vomiting, and/or dehydration (7); duodenal bleed (3); duodenal perforation (1). The recommended dose is 55 Gy, producing a probability of DLT of 0.24. The 2-year FFLP is 59% (95% confidence interval [CI]: 32-79). Median and 2-year overall survival are 14.8 months (95% CI: 12.6-22.2) and 30% (95% CI 17-45). Twelve patients underwent resection (10 R0, 2 R1) and survived a median of 32 months. High-dose radiation therapy with concurrent FDR-G can be delivered safely. The encouraging efficacy data suggest that outcome may be improved in unresectable patients through intensification of local therapy. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. A phase II trial of fixed-dosed rate gemcitabine in platinum-resistant ovarian cancer: a GEICO (Grupo Español de Investigación en Cáncer de Ovario) Trial.

    Ojeda Gonzalez, Belen; Gonzalez Martin, Antonio; Bover Barcelo, Isabel; Fabregat i Mayol, Xavier; Mellado, Begoña; Rubio Perez, María Jesus; Alonso Carrion, Lorenzo; Casado Herraez, Antonio; Calvo Garcia, Elisa; Churruca Galaz, Cristina; Arcusa Lanza, Angels; Herrero Ibañez, Ana; Adrover Cebrian, Encarna; Poveda Velasco, Andres

    2008-10-01

    Gemcitabine has well-recognized activity in the treatment of ovarian cancer. Fixed-dose rate (FDR) delivery has been proposed as a more rationale way to administer gemcitabine, to avoid saturation of the enzyme that catalyzes its intracellular transformation into the active metabolites, difluorodeoxycitidine biphosphate, and triphosphate. Our aim was to assess clinical activity of gemcitabine delivered by FDR infusion in patients with platinum resistant ovarian cancer. Patients with platinum-resistant ovarian cancer received gemcitabine 1000 mg/m(2) over 120 minutes on days 1 and 8 of each cycle. Cycles were repeated every 3 weeks, and up to 6 cycles were delivered. Forty-eight patients were included in the study. Among 41 patients evaluable for response, 9 clinical responses (1 complete response and 8 partial responses) were observed, achieving a global response rate of 22%. Grade 3 to 4 hematological toxicity consisted of anemia (15% of patients), neutropenia (24%), and thrombopenia (10%). One patient died due to septic shock. The main grade 3 to 4 nonhematological toxicity was asthenia (7 patients, 17%). Activity of gemcitabine administered by FDR infusion in patients with platinum-resistant ovarian cancer seems similar to that achieved using 30-minute infusions, with higher toxicity.

  15. Fixed automated spray technology.

    2011-04-19

    This research project evaluated the construction and performance of Boschungs Fixed Automated : Spray Technology (FAST) system. The FAST system automatically sprays de-icing material on : the bridge when icing conditions are about to occur. The FA...

  16. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    El-Amin, Mohamed; Sun, Shuyu

    2010-01-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  17. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    El-Amin, Mohamed

    2010-12-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  18. Fixed mobile convergence handbook

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  19. All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part II: Multiple-unit FDPs.

    Pjetursson, Bjarni Elvar; Sailer, Irena; Makarov, Nikolay Alexandrovich; Zwahlen, Marcel; Thoma, Daniel Stefan

    2015-06-01

    To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and esthetic complications. Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported FDPs with a mean follow-up of at least 3 years. This was complemented by an additional hand search and the inclusion of 10 studies from a previous systematic review [1]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year survival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2-96.5%). The estimated survival rate of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4-94.0%), the survival rate of glass-infiltrated alumina FDPs was 86.2% (95% CI: 69.3-94.2%) and the survival rate of densely sintered zirconia FDPs was 90.4% (95% CI: 84.8-94.0%) in 5 years of function. Even though the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences did not reach statistical significance except for the glass-infiltrated alumina FDPs (p=0.05). A significantly higher incidence of caries in abutment teeth was observed for densely sintered zirconia FDPs compared to metal-ceramic FDPs. Significantly more framework fractures were reported for reinforced glass ceramic FDPs (8.0%) and glass-infiltrated alumina FDPs (12.9%) compared to metal-ceramic FDPs (0.6%) and densely sintered zirconia FDPs (1.9%) in 5 years in function. However, the incidence of ceramic fractures and loss of retention was significantly (p=0.018 and 0.028 respectively) higher for densely sintered zirconia FDPs compared to all other types of FDPs. Survival rates of all

  20. Incidence of premature estrus in lactating dairy cows and conception rates to standing estrus or fixed-time inseminations after synchronization using GnRH and PGF(2alpha).

    DeJarnette, J M; Salverson, R R; Marshall, C E

    2001-07-03

    Fixed-time AI (TAI) after GnRH-PGF(2alpha)-GnRH treatment is a method to achieve pregnancies in dairy herds without estrous detection. However, cows that fail to respond to the initial GnRH may have compromised TAI conception rates due to asynchronous ovarian response. This study documented the percentage of GnRH-treated Holstein cows (n=345) in two herds that displayed estrus at an inopportune time for optimum TAI conception rate (conception rates of two TAI protocols in cows that did not display PE. At biweekly herd health exams, cows diagnosed as not pregnant to a previous AI and cows >80 days postpartum with no AI were treated with 100 microg GnRH (day -7) and 25mg PGF(2alpha) (day 0). Cows detected in PE by twice-daily visual observation from day -7 to day 2 were bred by AI 8-12h later. Cows not detected in PE were randomly assigned by parity, body condition score, and postpartum interval to receive either: (1) 100microg GnRH at 48h after PGF(2alpha) and TAI 16 to 18h later (Ovsynch); or (2) TAI at 72h post-PGF(2alpha) and a concurrent 100 microg GnRH injection to those cows not detected in estrus between 48 and 72h post-PGF(2alpha) (modified Ovsynch (MOV)). All hormone injections were im. Twenty percent (68/345) of the cows were detected in estrus before 48 after PGF(2alpha), of which 5% (17/345) were detected in estrus before PGF(2alpha) (Conception rates were not affected by treatment (PE versus Ovsynch versus MOV; 32% (21/65) versus 30% (37/125) versus 32% (47/145); P>0.10). However, within MOV-treated cows, conception rates were greater (Prates are to be achieved. Although additional estrous detection is required compared to Ovsynch, reduced cow handling and hormone usage, efficient use of expensive semen through greater conception rates in cows detected in estrus, and comparable TAI conception rates, suggests the MOV protocol may be a cost effective alternative to Ovsynch in many dairy herd reproductive management programs.

  1. Classification of tidal inlets along the Central east coast of India

    Reddy, N.A.; Vikas, M.; Rao, S.; JayaKumar S.

    ) as long as the alongshore sediment bypasses the tidal inlet. Classification of coastal systems in a broader view is necessary for the management of tidal inlets. There are several methods to classify tidal inlets based on different perspectives namely geo...

  2. Inlet Trade Study for a Low-Boom Aircraft Demonstrator

    Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.

    2016-01-01

    Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.

  3. Flow Simulation of Supersonic Inlet with Bypass Annular Duct

    Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.

    2011-01-01

    A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.

  4. Unstart Coupling Mechanism Analysis of Multiple-Modules Hypersonic Inlet

    Jichao Hu

    2013-01-01

    Full Text Available The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  5. Performance Prediction of Darrieus-Type Hydroturbine with Inlet Nozzle Operated in Open Water Channels

    Nakashima, K.; Watanabe, S.; Matsushita, D.; Tsuda, S.; Furukawa, A.

    2016-11-01

    Small hydropower is one of the renewable energies and is expected to be effectively used for local supply of electricity. We have developed Darrieus-type hydro-turbine systems, and among them, the Darrieus-turbine with a weir and a nozzle installed upstream of turbine is, so far, in success to obtain more output power by gathering all water into the turbine. However, there can several cases exist, in which installing the weir covering all the flow channel width is unrealistic, and in such cases, the turbine should be put alone in open channels without upstream weir. Since the output power is very small in such a utilization of small hydropower, it is important to derive more power for the cost reduction. In the present study, we parametrically investigate the preferable shape of the inlet nozzle for the Darrieus-type hydroturbine operated in an open flow channel. Experimental investigation is carried out in the open channel in our lab. Tested inlet nozzles are composed of two flat plates with the various nozzle converging angles and nozzle outlet (runner inlet) widths with the nozzle inlet width kept constant. As a result, the turbine with the nozzles having large converging angle and wide outlet width generates higher power. Two-dimensional unsteady numerical simulation is also carried out to qualitatively understand the flow mechanism leading to the better performance of turbine. Since the depth, the width and the flow rate in the real open flow channels are different from place to place and, in some cases from time to time, it is also important to predict the onsite performance of the hydroturbine from the lab experiment at planning stage. One-dimensional stream-tube model is developed for this purpose, in which the Darrieus-type hydroturbine with the inlet nozzle is considered as an actuator-disk modelled based on our experimental and numerical results.

  6. Should we attempt global (inlet engine airframe) control design?

    Carlin, C. M.

    1980-01-01

    The feasibility of multivariable design of the entire airplane control system is briefly addressed. An intermediate step in that direction is to design a control for an inlet engine augmentor system by using multivariable techniques. The supersonic cruise large scale inlet research program is described which will provide an opportunity to develop, integrate, and wind tunnel test a control for a mixed compression inlet and variable cycle engine. The integrated propulsion airframe control program is also discussed which will introduce the problem of implementing MVC within a distributed processing avionics architecture, requiring real time decomposition of the global design into independent modules in response to hardware communication failures.

  7. Simultaneous mass detection for direct inlet mass spectrometry

    Gordon, R.L.

    1979-05-01

    The evolution of analytical techniques for application in trace analysis has led to interest in practical methods for real-time monitoring. Direct inlet mass spectrometry (DIMS) has been the subject of considerable activity in recent years. A DIMS instrument is described which consists of an inlet system designed to permit particles entrained in the inlet air stream to strike a hot, oxidized rhenium filament which serves as a surface ionization source. A mass analyzer and detection system then permits identification of the elemental composition of particulates which strike the filament

  8. Development of a thermodynamic low order model for a twin screw expander with emphasis on pulsations in the inlet pipe

    Papes, Iva; Degroote, Joris; Vierendeels, Jan

    2016-01-01

    Highlights: • A multi-chamber model is developed from the mass and energy conservation laws. • To better predict inlet pipe pulsations a 3D inlet pipe model is coupled to it. • Flow coefficients are derived from 3D CFD calculations. • Maximal deviation between the full CFD and the presented model is around 5%. • This model is a good compromise between accuracy and computational resources. - Abstract: A twin screw expander is a positive displacement machine used in various applications of waste heat recovery. The performance of this machine is influenced by internal leakages, gas pulsations formed in the inlet pipe and the properties of the refrigerant. In this paper a multi-chamber mathematical model of a twin screw expander is presented to predict its performance. From the mass and energy conservation laws, differential equations are derived which are then solved together with the appropriate Equation of State (EoS) in the instantaneous control volumes. In order to calculate the mass flow rates through leakage paths more accurately, flow coefficients used in the converging nozzle model were derived from 3D Computational Fluid Dynamic (CFD) calculation. Due to high gas pulsation levels at the inlet port, a coupling with a 3D CFD inlet pipe model is introduced in order to better predict throttling losses. The maximal deviation between predictions by the developed model and 3D CFD calculations of the complete machine is around 5% for the mass flow rate and the power output.

  9. Biosorption of cobalt(II) with sunflower biomass from aqueous solutions in a fixed bed column and neural networks modelling.

    Oguz, Ensar; Ersoy, Muhammed

    2014-01-01

    The effects of inlet cobalt(II) concentration (20-60 ppm), feed flow rate (8-19 ml/min) and bed height (5-15 cm), initial solution pH (3-5) and particle size (0.25shells of sunflower biomass was found to be 1.82 m(2)/g. A relationship between the predicted results of the ANN model and experimental data was conducted. The ANN model yielded determination coefficient of (R(2) 0.972), standard deviation ratio (0.166), mean absolute error (0.0158) and root mean square error (0.0141). The results indicated that the shells of the sunflower biomass is a suitable biosorbent for the uptake of cobalt(II) in fixed bed columns. © 2013 Published by Elsevier Inc.

  10. Axial Fan Blade Vibration Assessment under Inlet Cross-Flow Conditions Using Laser Scanning Vibrometry

    Till Heinemann

    2017-08-01

    Full Text Available In thermal power plants equipped with air-cooled condensers (ACCs, axial cooling fans operate under the influence of ambient flow fields. Under inlet cross-flow conditions, the resultant asymmetric flow field is known to introduce additional harmonic forces to the fan blades. This effect has previously only been studied numerically or by using blade-mounted strain gauges. For this study, laser scanning vibrometry (LSV was used to assess fan blade vibration under inlet cross-flow conditions in an adapted fan test rig inside a wind tunnel test section. Two co-rotating laser beams scanned a low-pressure axial fan, resulting in spectral, phase-resolved surface vibration patterns of the fan blades. Two distinct operating points with flow coefficients of 0.17 and 0.28 were examined, with and without inlet cross-flow influence. While almost identical fan vibration patterns were found for both reference operating points, the overall blade vibration increased by 100% at the low fan flow rate as a result of cross-flow, and by 20% at the high fan flow rate. While numerically predicted natural frequency modes could be confirmed from experimental data as minor peaks in the vibration amplitude spectrum, they were not excited significantly by cross-flow. Instead, primarily higher rotation-rate harmonics were amplified; that is, a synchronous blade-tip flapping was strongly excited at the blade-pass frequency.

  11. Precise Point Positioning with Partial Ambiguity Fixing.

    Li, Pan; Zhang, Xiaohong

    2015-06-10

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

  12. A Phase I/II Trial of Intensity Modulated Radiation (IMRT) Dose Escalation With Concurrent Fixed-dose Rate Gemcitabine (FDR-G) in Patients With Unresectable Pancreatic Cancer

    Ben-Josef, Edgar; Schipper, Mathew; Francis, Isaac R.; Hadley, Scott; Ten-Haken, Randall; Lawrence, Theodore; Normolle, Daniel; Simeone, Diane M.; Sonnenday, Christopher; Abrams, Ross; Leslie, William; Khan, Gazala; Zalupski, Mark M.

    2012-01-01

    Purpose: Local failure in unresectable pancreatic cancer may contribute to death. We hypothesized that intensification of local therapy would improve local control and survival. The objectives were to determine the maximum tolerated radiation dose delivered by intensity modulated radiation with fixed-dose rate gemcitabine (FDR-G), freedom from local progression (FFLP), and overall survival (OS). Methods and Materials: Eligibility included pathologic confirmation of adenocarcinoma, radiographically unresectable, performance status of 0-2, absolute neutrophil count of ≥1500/mm 3 , platelets ≥100,000/mm 3 , creatinine 2 /100 min intravenously) was given on days −22 and −15, 1, 8, 22, and 29. Intensity modulated radiation started on day 1. Dose levels were escalated from 50-60 Gy in 25 fractions. Dose-limiting toxicity was defined as gastrointestinal toxicity grade (G) ≥3, neutropenic fever, or deterioration in performance status to ≥3 between day 1 and 126. Dose level was assigned using TITE-CRM (Time-to-Event Continual Reassessment Method) with the target dose-limiting toxicity (DLT) rate set to 0.25. Results: Fifty patients were accrued. DLTs were observed in 11 patients: G3/4 anorexia, nausea, vomiting, and/or dehydration (7); duodenal bleed (3); duodenal perforation (1). The recommended dose is 55 Gy, producing a probability of DLT of 0.24. The 2-year FFLP is 59% (95% confidence interval [CI]: 32-79). Median and 2-year overall survival are 14.8 months (95% CI: 12.6-22.2) and 30% (95% CI 17-45). Twelve patients underwent resection (10 R0, 2 R1) and survived a median of 32 months. Conclusions: High-dose radiation therapy with concurrent FDR-G can be delivered safely. The encouraging efficacy data suggest that outcome may be improved in unresectable patients through intensification of local therapy.

  13. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  14. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  15. Cook Inlet and Kenai Peninsula, Alaska ESI: INDEX (Index Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet and Kenai...

  16. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Department of Water Resources Development and Management, Indian Institute ... on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). ... nature of flows is clearly understood with the help of advanced instrumentation.

  17. PIE Nacelle Flow Analysis and TCA Inlet Flow Quality Assessment

    Shieh, C. F.; Arslan, Alan; Sundaran, P.; Kim, Suk; Won, Mark J.

    1999-01-01

    This presentation includes three topics: (1) Analysis of isolated boattail drag; (2) Computation of Technology Concept Airplane (TCA)-installed nacelle effects on aerodynamic performance; and (3) Assessment of TCA inlet flow quality.

  18. Cook Inlet and Kenai Peninsula, Alaska ESI: NESTS (Nest Points)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  19. AFSC/REFM: Cook Inlet Beluga Whale Economic Survey 2013

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project was to collect data to understand the publics preferences for protecting the Cook Inlet beluga whale (CIBW), a distinct population...

  20. Cook Inlet and Kenai Peninsula, Alaska ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for razor clams in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  1. Cook Inlet and Kenai Peninsula, Alaska ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for herring spawning areas in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent...

  2. Cook Inlet and Kenai Peninsula, Alaska ESI: FISHL (Fish Lines)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for anadromous fish streams in Cook Inlet and Kenai Peninsula, Alaska. Vector lines in this data set represent...

  3. Is the Price Right? An Analysis of ETP's Fixed Fees.

    Moore, Richard W.; Blake, Daniel R.; Honig, Michele L.; Cohen, Michael D.

    The Employment Training Panel (ETP) contracted with California State University-Northridge to review the fixed fee structure ETP used to pay contractors for training provided under ETP. Three research questions were investigated: what other institutions use the fixed fee and what they pay for; whether ETP's fixed-fee rates were reasonable in…

  4. Carbon Dioxide Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy, and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject, and physiological differences between subjects. Computational Fluid Dynamics (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit, and the Enhanced Mobility Advanced Crew Escape Suit. Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the CO2 production measured by an additional gas analyzer at the air outlet from the suit. Real-time metabolic rate measurements were used to adjust the treadmill workload to meet

  5. The Scale Effects of Engineered Inlets in Urban Hydrologic Processes

    Shevade, L.; Montalto, F. A.

    2017-12-01

    Runoff from urban surfaces is typically captured by engineered inlets for conveyance to receiving water bodies or treatment plants. Normative hydrologic and hydraulic (H&H) modeling tools generally assume 100% efficient inlets, though observations by the authors suggest this assumption is invalid. The discrepancy is key since the more efficiently the inlet, the more linearly hydrologic processes scale with catchment area. Using several years of remote sensing, the observed efficiencies of urban green infrastructure (GI) facility inlets in New York City are presented, as a function of the morphological and climatological properties of their catchments and events. The rainfall-runoff response is modeled with EPA to assess the degree of inaccuracy that the assumption of efficient inlets introduces in block and neighborhood-scale simulations. Next, an algorithm is presented that incorporates inlet efficiency into SWMM and the improved predictive skill evaluated using Nash-Sutcliffe and root-mean-square error (RMSE). The results are used to evaluate the extent to which decentralized green stormwater management facilities positioned at the low points of urban catchments ought to be designed with larger capacities than their counterparts located further upslope.

  6. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  7. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    Luo, Xianwu; Zhang, Yao; Peng, Junqi; Xu, Hongyuan; Yu, Weiping

    2008-01-01

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m 3 min -1 .min -1 and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-ε turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  8. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    Luo, Xianwu; Zhang, Yao; Peng, Junqi; Xu, Hongyuan [Tsinghua University, Beijing (China); Yu, Weiping [Zhejiang Pump Works, Zhejiang (China)

    2008-10-15

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m{sup 3}min{sup -1}.min{sup -1} and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-{epsilon} turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  9. Fixed target flammable gas upgrades

    Schmitt, R.; Squires, B.; Gasteyer, T.; Richardson, R.

    1996-12-01

    In the past, fixed target flammable gas systems were not supported in an organized fashion. The Research Division, Mechanical Support Department began to support these gas systems for the 1995 run. This technical memo describes the new approach being used to supply chamber gasses to fixed target experiments at Fermilab. It describes the engineering design features, system safety, system documentation and performance results. Gas mixtures provide the medium for electron detection in proportional and drift chambers. Usually a mixture of a noble gas and a polyatomic quenching gas is used. Sometimes a small amount of electronegative gas is added as well. The mixture required is a function of the specific chamber design, including working voltage, gain requirements, high rate capability, aging and others. For the 1995 fixed target run all the experiments requested once through gas systems. We obtained a summary of problems from the 1990 fixed target run and made a summary of the operations logbook entries from the 1991 run. These summaries primarily include problems involving flammable gas alarms, but also include incidents where Operations was involved or informed. Usually contamination issues were dealt with by the experimenters. The summaries are attached. We discussed past operational issues with the experimenters involved. There were numerous incidents of drift chamber failure where contaminated gas was suspect. However analyses of the gas at the time usually did not show any particular problems. This could have been because the analysis did not look for the troublesome component, the contaminant was concentrated in the gas over the liquid and vented before the sample was taken, or that contaminants were drawn into the chambers directly through leaks or sub-atmospheric pressures. After some study we were unable to determine specific causes of past contamination problems, although in argon-ethane systems the problems were due to the ethane only

  10. Detecting Extracellular Carbonic Anhydrase Activity Using Membrane Inlet Mass Spectrometry

    Delacruz, Joannalyn; Mikulski, Rose; Tu, Chingkuang; Li, Ying; Wang, Hai; Shiverick, Kathleen T.; Frost, Susan C.; Horenstein, Nicole A.; Silverman, David N.

    2010-01-01

    Current research into the function of carbonic anhydrases in cell physiology emphasizes the role of membrane-bound carbonic anhydrases, such as carbonic anhydrase IX that has been identified in malignant tumors and is associated with extracellular acidification as a response to hypoxia. We present here a mass spectrometric method to determine the extent to which total carbonic anhydrase activity is due to extracellular carbonic anhydrase in whole cell preparations. The method is based on the biphasic rate of depletion of 18O from CO2 measured by membrane inlet mass spectrometry. The slopes of the biphasic depletion are a sensitive measure of the presence of carbonic anhydrase outside and inside of the cells. This property is demonstrated here using suspensions of human red cells in which external carbonic anhydrase was added to the suspending solution. It is also applied to breast and prostate cancer cells which both express exofacial carbonic anhydrase IX. Inhibition of external carbonic anhydrase is achieved by use of a membrane impermeant inhibitor that was synthesized for this purpose, p-aminomethylbenzenesulfonamide attached to a polyethyleneglycol polymer. PMID:20417171

  11. Least fixed points revisited

    J.W. de Bakker (Jaco)

    1975-01-01

    textabstractParameter mechanisms for recursive procedures are investigated. Contrary to the view of Manna et al., it is argued that both call-by-value and call-by-name mechanisms yield the least fixed points of the functionals determined by the bodies of the procedures concerned. These functionals

  12. Characterizing fixed points

    Sanjo Zlobec

    2017-04-01

    Full Text Available A set of sufficient conditions which guarantee the existence of a point x⋆ such that f(x⋆ = x⋆ is called a "fixed point theorem". Many such theorems are named after well-known mathematicians and economists. Fixed point theorems are among most useful ones in applied mathematics, especially in economics and game theory. Particularly important theorem in these areas is Kakutani's fixed point theorem which ensures existence of fixed point for point-to-set mappings, e.g., [2, 3, 4]. John Nash developed and applied Kakutani's ideas to prove the existence of (what became known as "Nash equilibrium" for finite games with mixed strategies for any number of players. This work earned him a Nobel Prize in Economics that he shared with two mathematicians. Nash's life was dramatized in the movie "Beautiful Mind" in 2001. In this paper, we approach the system f(x = x differently. Instead of studying existence of its solutions our objective is to determine conditions which are both necessary and sufficient that an arbitrary point x⋆ is a fixed point, i.e., that it satisfies f(x⋆ = x⋆. The existence of solutions for continuous function f of the single variable is easy to establish using the Intermediate Value Theorem of Calculus. However, characterizing fixed points x⋆, i.e., providing answers to the question of finding both necessary and sufficient conditions for an arbitrary given x⋆ to satisfy f(x⋆ = x⋆, is not simple even for functions of the single variable. It is possible that constructive answers do not exist. Our objective is to find them. Our work may require some less familiar tools. One of these might be the "quadratic envelope characterization of zero-derivative point" recalled in the next section. The results are taken from the author's current research project "Studying the Essence of Fixed Points". They are believed to be original. The author has received several feedbacks on the preliminary report and on parts of the project

  13. Comparison of Engine/Inlet Distortion Measurements with MEMS and ESP Pressure Sensors

    Soto, Hector L.; Hernandez, Corey D.

    2004-01-01

    A study of active-flow control in a small-scale boundary layer ingestion inlet was conducted at the NASA Langley Basic Aerodynamic Research Tunnel (BART). Forty MEMS pressure sensors, in a rake style configuration, were used to examine both the mean (DC) and high frequency (AC) components of the total pressure across the inlet/engine interface plane. The mean component was acquired and used to calculate pressure distortion. The AC component was acquired separately, at a high sampling rate, and is used to study the unsteady effects of the active-flow control. An identical total pressure rake, utilizing an Electronically Scanned Pressure (ESP) system, was also used to calculate distortion; a comparison of the results obtained using the two rakes is presented.

  14. Air Motion and Thermal Environment in Pig Housing Facilities with Diffuse Inlet

    Jacobsen, Lis

    A ventilation system with ambient air supply through diffuse ceiling used in pig production facilities is presented. The climatic conditions were examined both experimentally and numerically in an full scale experimental room and the inlet boundary conditions of the diffuse inlet were examined...... in ambient temperature and air exchange rate. The effect of housing equipment on environmental conditions has been examined both experimental and numerically and it was found that impervious housing equipment has a significant effect on the climatic conditions close to the wall in the occupational zone...... in a wind tunnel model. In the full scale experiments the focus has been on the correlation between variations in ambient climatic conditions and changes in environmental condition in the occupational zone. It was found that the environmental conditions in the occupational zone were independent on changes...

  15. Effects of water inlet configuration in a service reservoir applying CFD modelling

    Carolina Montoya Pachongo

    2016-01-01

    Full Text Available This study investigated the state of a service reservoir of a drinking water distribution network. Numerical simulation was applied to establish its flow pattern, mixing conditions, and free residual chlorine decay. The influence of the change in the water inlet configuration on these characteristics was evaluated. Four scenarios were established with different water level and flow rate as the differences between the first three scenarios. The fourth scenario was evaluated to assess the influence of the inlet configuration, momentum flow and water level on hydrodynamic conditions within the service reservoir. The distribution of four nozzles of 152.4mm diameter was identified as a viable measure to preserve the water quality in this type of hydraulic structures.

  16. Thermal behavior of latent thermal energy storage unit using two phase change materials: Effects of HTF inlet temperature

    Fouzi Benmoussa

    2017-09-01

    Full Text Available This work presents a numerical study of the thermal behavior of shell-and-tube latent thermal energy storage (LTES unit using two phase change materials (PCMs. The heat transfer fluid (HTF flow through the inner tube and transfer the heat to PCMs. First, a mathematical model is developed based on the enthalpy formulation and solved through the governing equations. Second, the effects of HTF inlet temperature on the unsteady temperature evolution of PCMs, the total energy stored evolution as well as the total melting time is studied. Numerical results show that for all HTF inlet temperature, melting rate of PCM1 is the fastest and that of PCM2 is the slowest; increasing the HTF inlet temperature considerably increases the temperature evolution of PCMs. The maximum energy stored is observed in PCM2 with high melting temperature and high specific heat; heat storage capacity is large for high HTF inlet temperature. When the HTF inlet temperature increases from 338 K to 353 K, decreasing degree of melting time of PCM2 is the biggest from 1870 s to 490 s, which reduces about 73.8%; decreasing degree of melting time of PCM1 is the smallest from 530 s to 270 s, which reduces about 49.1%.

  17. A study on flow development in an APU-style inlet and its effect on centrifugal compressor performance

    Lou, Fangyuan

    The objectives of this research were to investigate the flow development inside an APU-style inlet and its effect on centrifugal compressor performance. The motivation arises from the increased applications of gas turbine engines installed with APU-style inlets such as unmanned aerial vehicles, auxiliary power units, and helicopters. The inlet swirl distortion created from these complicated inlet systems has become a major performance and operability concern. To improve the integration between the APU-style inlet and gas turbine engines, better understanding of the flow field in the APU-style inlet and its effect on gas turbine is necessary. A research facility for the purpose of performing an experimental investigation of the flow field inside an APU-style inlet was developed. A subcritical air ejector is used to continuously flow the inlet at desired corrected mass flow rates. The facility is capable of flowing the APU inlet over a wide range of corrected mass flow rate that matches the same Mach numbers as engine operating conditions. Additionally, improvement in the system operational steadiness was achieved by tuning the pressure controller using a PID control method and utilizing multi-layer screens downstream of the APU inlet. Less than 1% relative unsteadiness was achieved for full range operation. The flow field inside the rectangular-sectioned 90? bend of the APU-style inlet was measured using a 3-Component LDV system. The structures for both primary flow and the secondary flow inside the bend were resolved. Additionally, the effect of upstream geometry on the flow development in the downstream bend was also investigated. Furthermore, a Single Stage Centrifugal Compressor research facility was developed at Purdue University in collaboration with Honeywell to operate the APU-style inlet at engine conditions with a compressor. To operate the facility, extensive infrastructure for facility health monitoring and performance control (including lubrication

  18. Characterisation and airborne deployment of a new counterflow virtual impactor inlet

    T. Shingler

    2012-06-01

    Full Text Available A new counterflow virtual impactor (CVI inlet is introduced with details of its design, laboratory characterisation tests and deployment on an aircraft during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE. The CVI inlet addresses three key issues in previous designs; in particular, the inlet operates with: (i negligible organic contamination; (ii a significant sample flow rate to downstream instruments (∼15 l min−1 that reduces the need for dilution; and (iii a high level of accessibility to the probe interior for cleaning. Wind tunnel experiments characterised the cut size of sampled droplets and the particle size-dependent transmission efficiency in various parts of the probe. For a range of counter-flow rates and air velocities, the measured cut size was between 8.7–13.1 μm. The mean percentage error between cut size measurements and predictions from aerodynamic drag theory is 1.7%. The CVI was deployed on the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS Twin Otter for thirty flights during E-PEACE to study aerosol-cloud-radiation interactions off the central coast of California in July and August 2011. Results are reported to assess the performance of the inlet including comparisons of particle number concentration downstream of the CVI and cloud drop number concentration measured by two independent aircraft probes. Measurements downstream of the CVI are also examined from one representative case flight coordinated with shipboard-emitted smoke that was intercepted in cloud by the Twin Otter.

  19. The effect of inlet waveforms on computational hemodynamics of patient-specific intracranial aneurysms.

    Xiang, J; Siddiqui, A H; Meng, H

    2014-12-18

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. CFD application to supersonic/hypersonic inlet airframe integration. [computational fluid dynamics (CFD)

    Benson, Thomas J.

    1988-01-01

    Supersonic external compression inlets are introduced, and the computational fluid dynamics (CFD) codes and tests needed to study flow associated with these inlets are outlined. Normal shock wave turbulent boundary layer interaction is discussed. Boundary layer control is considered. Glancing sidewall shock interaction is treated. The CFD validation of hypersonic inlet configurations is explained. Scramjet inlet modules are shown.

  1. Organics Verification Study for Sinclair and Dyes Inlets, Washington

    Kohn, Nancy P.; Brandenberger, Jill M.; Niewolny, Laurie A.; Johnston, Robert K.

    2006-09-28

    Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. Because significant cleanup and source control activities have been conducted in the inlets since the data supporting the 1998 303(d) listings were collected, two verification studies were performed to address the 303(d) segments that were listed for metal and organic contaminants in marine sediment. The Metals Verification Study (MVS) was conducted in 2003; the final report, Metals Verification Study for Sinclair and Dyes Inlets, Washington, was published in March 2004 (Kohn et al. 2004). This report describes the Organics Verification Study that was conducted in 2005. The study approach was similar to the MVS in that many surface sediment samples were screened for the major classes of organic contaminants, and then the screening results and other available data were used to select a subset of samples for quantitative chemical analysis. Because the MVS was designed to obtain representative data on concentrations of contaminants in surface sediment throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, aliquots of the 160 MVS sediment samples were used in the analysis for the Organics Verification Study. However, unlike metals screening methods, organics screening methods are not specific to individual organic compounds, and are not available for some target organics. Therefore, only the quantitative analytical results were used in the organics verification evaluation. The results of the Organics Verification Study showed that sediment quality outside of Sinclair Inlet is unlikely to be impaired because of organic contaminants. Similar to the results for metals, in Sinclair Inlet, the distribution of residual organic contaminants is generally limited to nearshore areas already within the

  2. A Phase I/II Trial of Intensity Modulated Radiation (IMRT) Dose Escalation With Concurrent Fixed-dose Rate Gemcitabine (FDR-G) in Patients With Unresectable Pancreatic Cancer

    Ben-Josef, Edgar, E-mail: edgar.ben-josef@uphs.upenn.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Mathew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Francis, Isaac R. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Hadley, Scott; Ten-Haken, Randall; Lawrence, Theodore; Normolle, Daniel [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Simeone, Diane M.; Sonnenday, Christopher [Department of Surgery, University of Michigan, Ann Arbor, Michigan (United States); Abrams, Ross [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States); Leslie, William [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States); Khan, Gazala; Zalupski, Mark M. [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States)

    2012-12-01

    Purpose: Local failure in unresectable pancreatic cancer may contribute to death. We hypothesized that intensification of local therapy would improve local control and survival. The objectives were to determine the maximum tolerated radiation dose delivered by intensity modulated radiation with fixed-dose rate gemcitabine (FDR-G), freedom from local progression (FFLP), and overall survival (OS). Methods and Materials: Eligibility included pathologic confirmation of adenocarcinoma, radiographically unresectable, performance status of 0-2, absolute neutrophil count of {>=}1500/mm{sup 3}, platelets {>=}100,000/mm{sup 3}, creatinine <2 mg/dL, bilirubin <3 mg/dL, and alanine aminotransferase/aspartate aminotransferase {<=}2.5 Multiplication-Sign upper limit of normal. FDR-G (1000 mg/m{sup 2}/100 min intravenously) was given on days -22 and -15, 1, 8, 22, and 29. Intensity modulated radiation started on day 1. Dose levels were escalated from 50-60 Gy in 25 fractions. Dose-limiting toxicity was defined as gastrointestinal toxicity grade (G) {>=}3, neutropenic fever, or deterioration in performance status to {>=}3 between day 1 and 126. Dose level was assigned using TITE-CRM (Time-to-Event Continual Reassessment Method) with the target dose-limiting toxicity (DLT) rate set to 0.25. Results: Fifty patients were accrued. DLTs were observed in 11 patients: G3/4 anorexia, nausea, vomiting, and/or dehydration (7); duodenal bleed (3); duodenal perforation (1). The recommended dose is 55 Gy, producing a probability of DLT of 0.24. The 2-year FFLP is 59% (95% confidence interval [CI]: 32-79). Median and 2-year overall survival are 14.8 months (95% CI: 12.6-22.2) and 30% (95% CI 17-45). Twelve patients underwent resection (10 R0, 2 R1) and survived a median of 32 months. Conclusions: High-dose radiation therapy with concurrent FDR-G can be delivered safely. The encouraging efficacy data suggest that outcome may be improved in unresectable patients through intensification of local

  3. Vilified and Fixed

    Jensen, Thessa; Westberg, Lysa

    , and imbalances of power between scholars and journalists on one side, and fans on the other are not rare occurrences. An analysis of a number of recent news articles, scholarly works, and websites, shows how the attempt of fixing fandom still prevails. Like Said's view on how the Orient is treated, fandom...... and tween website", 'Teen' managed to outrage fans. It took days and hundreds of comments, tweets, and mails to the publishers, before the article was taken down. Vilification in scholarly works and the media may have significantly lessened in recent years. Still, misunderstandings, applied exoticism...... is similarly exotisised, incorporated, and fixed. Scholars explain how to become better fans, attempting authority over fandom by applying rules to a culture, which already has their own. This, the notion of the 'better fan', devalues the existing discourses, rules, and traditions within fandom. The expert...

  4. Fixed-film processes. Part 1

    Canziani, R.

    1999-01-01

    Recently, full scale fixed-film or mixed suspended and fixed biomass bioreactors have been applied in many wastewater treatments plants. These process no longer depend on biomass settle ability and can be used to improve the performance of existing plants as required by more stringent discharge permit limits, especially for nutrients and suspended solid. Also, processes may work at high rates making it possible to build small footprint installations. Fixed-film process include trickling filter, moving bed reactors fluidized bed reactors. In the first part, the theoretical base governing fixed-film processes are briefly outlined with some simple examples of calculations underlining the main differences with conventional activated sludge processes [it

  5. Fixed-film processes. Part 2

    Canziani, R.

    1999-01-01

    Recently, full scale fixed-film or mixed suspended have been applied in many wastewater treatments plants. These processes no longer depend on biomass settle ability and can be used to improve the performance of existing plants as required by more stringent discharge permit limits, especially for nutrients suspended solids. Also, processes may work at high rates making is possible to build small footprint installations. Fixed-film processes include trickling filters (and combined suspended and fixed-films processes), rotating biological contactors, biological aerated submerged, filters moving bed reactors, fluidized bed reactors. In the first part, the theoretical based governing fixed-film processes are briefly outlined, with some simple examples of calculations, underlining the main differences with conventional activate sludge processes. In the second part, the most common types of reactors are reviewed [it

  6. CERN: Fixed target targets

    Anon.

    1993-03-15

    Full text: While the immediate priority of CERN's research programme is to exploit to the full the world's largest accelerator, the LEP electron-positron collider and its concomitant LEP200 energy upgrade (January, page 1), CERN is also mindful of its long tradition of diversified research. Away from LEP and preparations for the LHC proton-proton collider to be built above LEP in the same 27-kilometre tunnel, CERN is also preparing for a new generation of heavy ion experiments using a new source, providing heavier ions (April 1992, page 8), with first physics expected next year. CERN's smallest accelerator, the LEAR Low Energy Antiproton Ring continues to cover a wide range of research topics, and saw a record number of hours of operation in 1992. The new ISOLDE on-line isotope separator was inaugurated last year (July, page 5) and physics is already underway. The remaining effort concentrates around fixed target experiments at the SPS synchrotron, which formed the main thrust of CERN's research during the late 1970s. With the SPS and LEAR now approaching middle age, their research future was extensively studied last year. Broadly, a vigorous SPS programme looks assured until at least the end of 1995. Decisions for the longer term future of the West Experimental Area of the SPS will have to take into account the heavy demand for test beams from work towards experiments at big colliders, both at CERN and elsewhere. The North Experimental Area is the scene of larger experiments with longer lead times. Several more years of LEAR exploitation are already in the pipeline, but for the longer term, the ambitious Superlear project for a superconducting ring (January 1992, page 7) did not catch on. Neutrino physics has a long tradition at CERN, and this continues with the preparations for two major projects, the Chorus and Nomad experiments (November 1991, page 7), to start next year in the West Area. Delicate neutrino oscillation effects could become visible for the first

  7. Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet.

    Lutomski, Corinne A; El-Baba, Tarick J; Inutan, Ellen D; Manly, Cory D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

    2014-07-01

    This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, α-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples.

  8. Validation of helium inlet design for ITER toroidal field coil

    Boyer, C.; Seo, K.; Hamada, K.; Foussat, A.; Le Rest, M.; Mitchell, N.; Decool, P.; Savary, F.; Sgobba, S.; Weiss, K.P.

    2014-01-01

    The ITER organization has performed design and its validation tests on a helium inlet structure for the ITER Toroidal Field (TF) coil under collaboration with CERN, KIT, and CEA Cadarache. Detailed structural analysis was performed in order to optimize the weld shape. A fatigue resistant design on the fillet weld between the shell covers and the jacket is an important point on the helium inlet structure. A weld filler material was selected based on tensile test at liquid helium temperature after Nb 3 Sn reaction heat treatment. To validate the design of the weld joint, fatigue tests at 7 K were performed using heat-treated butt weld samples. A pressure drop measurement of a helium inlet mock-up was performed by using nitrogen gas at room temperature in order to confirm uniform flow distribution and pressure drop characteristic. These tests have validated the helium inlet design. Based on the validation, Japanese and European Union domestic agencies, which have responsibilities of the TF coil procurement, are preparing the helium inlet mock-up for a qualification test. (authors)

  9. Effect of inlet straighteners on centrifugal fan performance

    Bayomi, N.N.; Abdel Hafiz, A. [Faculty of Engineering, Mataria, Helwan University, 11718 Masaken, El-Helmia, Cairo (Egypt); Osman, A.M. [Faculty of Engineering, Shoubra, Zagazig University, Cairo (Egypt)

    2006-11-15

    The use of straighteners in the inlet duct of centrifugal fans is suggested for eliminating any inlet distortion. An experimental investigation was performed to study the effect of inlet straighteners on the performance characteristics of centrifugal fans. Two types of straighteners were used, circular tubes and zigzag cross section, with different lengths. Circular tubes with different diameters have been investigated. The study was conducted on three types of fans, namely radial, backward with exit blade angles 60{sup o} and 75{sup o} and forward with 105{sup o} and 120{sup o}. The results confirm that the inlet straighteners exhibit different effects on the fan performance for the different blade angles. Accordingly, the results indicate the selection of long circular tube straighteners with large diameter for radial blades, long zigzag type for backward 60{sup o} blade angle and short zigzag type for backward 75{sup o} blade angle. Generally, good improvements in efficiency are observed for radial and backward blades on account of a slight drop in static head. In addition, an increase in the flow margin up to 12% and a decrease in the noise level from 3 to 5dB are indicated compared to the free inlet condition. On the contrary, unfavorable influences are exerted on the forward fan performance. (author)

  10. Massive sediment bypassing on the lower shoreface offshore of a wide tidal inlet: Cat Island Pass, Louisiana

    Jaffe, B.E.; List, J.H.; Sallenger, A.H.

    1997-01-01

    Analysis of a series of historical bathymetric and shoreline surveys along the Louisiana coast west of the Mississippi River mouth detected a large area of deposition in water depths of 2.0–8.5 m offshore of a 9-km-wide tidal inlet, the Cat Island Pass/Wine Island Pass system. A 59.9 · 106 m3 sandy deposit formed from the 1930s–1980s, spanning 27 km in the alongshore direction, delineating the transport pathway for sediment bypassing offshore of the inlet on the shoreface. Bypassing connected the shorefaces of two barrier island systems, the Isles Dernieres and the Bayou Lafourche.The processes responsible for formation of this deposit are not well understood, but sediment-transport modeling suggests that sediment is transported primarily by wind-driven coastal currents during large storms and hurricanes. Deposition appears to be related to changes in shoreline orientation, closing of transport pathways into a large bay to the east and the presence of tidal inlets. This newly documented type of bypassing, an offshore bypassing of the inlet system, naturally nourished the immediate downdrift area, the eastern Isles Dernieres, where shoreface and shoreline erosion rates are about half of pre-bypassing rates. Erosion rates remained the same farther downdrift, where bypassing has not yet reached. As this offshore bypassing continues, the destruction of the Isles Dernieres will be slowed.

  11. Performance modeling of industrial gas turbines with inlet air filtration system

    Samuel O. Effiom

    2015-03-01

    Full Text Available The effect of inlet air filtration on the performance of two industrial gas turbines (GT is presented. Two GTs were modeled similar to GE LM2500+ and Alstom GT13 E2-2012, using TURBOMATCH and chosen to operate at environmental conditions of Usan offshore oilfield and Maiduguri dessert in Nigeria. The inlet pressure recovered (Precov from the selected filters used in Usan offshore, and Maiduguri ranged between 98.36≤Precov≤99.51% and 98.67≤Precov≤99.56% respectively. At reduced inlet Precov by 98.36% (1.66 kPa and, at a temperature above 15 °C (ISA, a reduction of 16.9%, and 7.3% of power output and efficiency was obtained using GT13 E2-2012, while a decrease of 14.8% and 4.7% exist for power output and efficiency with GE LM2500+. In addition, a reduction in mass flow rate of air and fuel under the same condition was between 4.3≤mair≤10.6% and 10.4≤mfuel≤11.5% for GT13 E2-2012 and GE LM2500+, correspondingly. However, the GE LM2500+ was more predisposed to intake pressure drops since it functioned at a higher overall pressure ratio. The results obtained were found worthwhile and could be the basis for filter selection and efficient compressor housing design in the locations concerned.

  12. Parametric Geometry, Structured Grid Generation, and Initial Design Study for REST-Class Hypersonic Inlets

    Ferlemann, Paul G.; Gollan, Rowan J.

    2010-01-01

    Computational design and analysis of three-dimensional hypersonic inlets with shape transition has been a significant challenge due to the complex geometry and grid required for three-dimensional viscous flow calculations. Currently, the design process utilizes an inviscid design tool to produce initial inlet shapes by streamline tracing through an axisymmetric compression field. However, the shape is defined by a large number of points rather than a continuous surface and lacks important features such as blunt leading edges. Therefore, a design system has been developed to parametrically construct true CAD geometry and link the topology of a structured grid to the geometry. The Adaptive Modeling Language (AML) constitutes the underlying framework that is used to build the geometry and grid topology. Parameterization of the CAD geometry allows the inlet shapes produced by the inviscid design tool to be generated, but also allows a great deal of flexibility to modify the shape to account for three-dimensional viscous effects. By linking the grid topology to the parametric geometry, the GridPro grid generation software can be used efficiently to produce a smooth hexahedral multiblock grid. To demonstrate the new capability, a matrix of inlets were designed by varying four geometry parameters in the inviscid design tool. The goals of the initial design study were to explore inviscid design tool geometry variations with a three-dimensional analysis approach, demonstrate a solution rate which would enable the use of high-fidelity viscous three-dimensional CFD in future design efforts, process the results for important performance parameters, and perform a sample optimization.

  13. Optimization of inlet plenum of A PBMR using surrogate modeling

    Lee, Sang-Moon; Kim, Kwang-Yong

    2009-01-01

    The purpose of present work is to optimize the design of inlet plenum of PBMR type gas cooled nuclear reactor numerically using a combining of three-dimensional Reynolds-averaged Navier-Stokes (RANS) analysis and surrogate modeling technique. Shear stress transport (SST) turbulence model is used as a turbulence closure. Three geometric design variables are selected, namely, rising channel diameter to plenum height ratio, aspect ratio of the plenum cross section, and inlet port angle. The objective function is defined as a linear combination of uniformity of three-dimensional flow distribution term and pressure drop in the inlet plenum and rising channels of PBMR term with a weighting factor. Twenty design points are selected using Latin-hypercube method of design of experiment and objective function values are obtained at each design point using RANS solver. (author)

  14. Effect of inlet cone pipe angle in catalytic converter

    Amira Zainal, Nurul; Farhain Azmi, Ezzatul; Arifin Samad, Mohd

    2018-03-01

    The catalytic converter shows significant consequence to improve the performance of the vehicle start from it launched into production. Nowadays, the geometric design of the catalytic converter has become critical to avoid the behavior of backpressure in the exhaust system. The backpressure essentially reduced the performance of vehicles and increased the fuel consumption gradually. Consequently, this study aims to design various models of catalytic converter and optimize the volume of fluid flow inside the catalytic converter by changing the inlet cone pipe angles. Three different geometry angles of the inlet cone pipe of the catalytic converter were assessed. The model is simulated in Solidworks software to determine the optimum geometric design of the catalytic converter. The result showed that by decreasing the divergence angle of inlet cone pipe will upsurge the performance of the catalytic converter.

  15. Boundary conditions for free surface inlet and outlet problems

    Taroni, M.

    2012-08-10

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well known that the flux scales with Ca 2/3, but this classical result is non-uniform as the contact angle approaches π. By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed. © 2012 Cambridge University Press.

  16. Tangential inlet supersonic separators: a novel apparatus for gas purification

    Wen, Chuang; Walther, Jens Honore; Yang, Yan

    2016-01-01

    A novel supersonic separator with a tangential inlet is designed to remove the condensable components from gas mixtures. The dynamic parameters of natural gas in the supersonic separation process are numerically calculated using the Reynolds stress turbulence model with the Peng-Robinson real gas...... be generated by the tangential inlet, and it increases to the maximum of 200 m/s at the nozzle throat due to decrease of the nozzle area of the converging part. The tangential velocity can maintain the value of about 160 m/s at the nozzle exit, and correspondingly generates the centrifugal acceleration of 3...

  17. The effect of inclusion of inlets in dual drainage modelling

    Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.; Djordjević, Slobodan

    2018-04-01

    In coupled sewer and surface flood modelling approaches, the flow process in gullies is often ignored although the overland flow is drained to sewer network via inlets and gullies. Therefore, the flow entering inlets is transferred to the sewer network immediately, which may lead to a different flood estimation than the reality. In this paper, we compared two modelling approach with and without considering the flow processes in gullies in the coupled sewer and surface modelling. Three historical flood events were adopted for model calibration and validation. The results showed that the inclusion of flow process in gullies can further improve the accuracy of urban flood modelling.

  18. Bedform evolution in a tidal inlet referred from wavelet analysis

    Fraccascia, Serena; Winter, Christian; Ernstsen, Verner Brandbyge

    2011-01-01

    Bedforms are common morphological features in subaqueous and aeolian environments and their characterization is commonly the first step to better understand forcing factors acting in the system. The aim of this study was to investigate the spectral characteristics of compound bedforms in a tidal...... inlet and evaluate how they changed over consecutive years, when morphology was modified and bedforms migrated. High resolution bathymetric data from the Grådyb tidal inlet channel (Danish Wadden Sea) from seven years from 2002 to 2009 (not in 2004) were analyzed. Continuous wavelet transform of bed...

  19. Design and experimental validation of the inlet guide vane system of a mini hydraulic bulb-turbine

    Ferro, L.M.C. [Department of Mechanical Engineering, Escola Superior de Tecnologia de Setubal, Polytechnic Institute of Setubal, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais,1049-001 Lisboa (Portugal); Gato, L.M.C.; Falcao, A.F.O. [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais,1049-001 Lisboa (Portugal)

    2010-09-15

    The paper presents a fast design method for the inlet guide vanes of low-cost mini hydraulic bulb turbines. The guide vanes are positioned between two conical surfaces with a common vertex and have constant thickness distribution, except close to the leading and the trailing edges. The conical-walled inlet guide vane row is designed using a quasi-three-dimensional calculation method, by prescribing the angular-momentum distribution along the span at the outlet section of the guide vanes. The meridional through-flow is computed by a streamline curvature method and the blade-to-blade flow by a singularity surface method. The stagger angle and the vane camber are computed to fulfil the required design circulation and zero-incidence flow at the leading edge. The final vane shape is a single-curvature surface with straight leading and trailing edges. To validate the design method, a conical-walled inlet guide vane row nozzle-model with six fixed vanes was designed, manufactured and tested in an airflow rig. Traversing measurements along the circumferential and radial directions were made with a five-hole probe. The experimental results are compared with the prescribed design conditions and with numerical results from the three-dimensional inviscid and viscous flow computed with the FLUENT code. (author)

  20. Exergy, Economic and Environmental Analyses of Gas Turbine Inlet Air Cooling with a Heat Pump Using a Novel System Configuration

    Mohammad Reza Majdi Yazdi

    2015-10-01

    Full Text Available Gas turbines incur a loss of output power during hot seasons due to high ambient air temperatures, and input air cooling systems are often used to partly offset this problem. Here, results are reported for an investigation of the utilization of a heat pump to cool the inlet air of a gas turbine compressor. The analyses are carried out for two climates: the city of Yazd, Iran, which has a hot, arid climate, and Tehran, Iran, which has a temperate climate. The heat pump input power is obtained from the gas turbine. The following parameters are determined, with and without the heat pump: net output power, first and second law efficiencies, quantities and costs of environmental pollutants, entropy generation and power generation. The results suggest that, by using the air-inlet cooling system, the mean output power increases during hot seasons by 11.5% and 10% for Yazd and Tehran, respectively, and that the costs of power generation (including pollution costs decrease by 11% and 10% for Yazd and Tehran, respectively. Also, the rate of generation of pollutants such as NOx and CO decrease by about 10% for Yazd and 35% for Tehran, while the average annual entropy generation rate increases by 9% for Yazd and 7% for Tehran, through air-inlet cooling. The average increase of the system first law efficiency is 2% and of the system second law efficiency is 1.5% with the inlet-air cooling system.

  1. Fixed target beams

    Kain, V; Cettour-Cave, S; Cornelis, K; Fraser, M A; Gatignon, L; Goddard, B; Velotti, F

    2017-01-01

    The CERN SPS (Super Proton Synchrotron) serves asLHC injector and provides beam for the North Area fixedtarget experiments. At low energy, the vertical acceptancebecomes critical with high intensity large emittance fixed tar-get beams. Optimizing the vertical available aperture is a keyingredient to optimize transmission and reduce activationaround the ring. During the 2016 run a tool was developed toprovide an automated local aperture scan around the entirering.The flux of particles slow extracted with the1/3inte-ger resonance from the Super Proton Synchrotron at CERNshould ideally be constant over the length of the extractionplateau, for optimum use of the beam by the fixed target ex-periments in the North Area. The extracted intensity is con-trolled in feed-forward correction of the horizontal tune viathe main SPS quadrupoles. The Mains power supply noiseat 50 Hz and harmonics is also corrected in feed-forwardby small amplitude tune modulation at the respective fre-quencies with a dedicated additional quad...

  2. CFD analysis of hot spot formation through a fixed bed reactor of Fischer-Tropsch synthesis

    Hamed Aligolzadeh

    2015-12-01

    Full Text Available One of the interesting methods for conversion of synthesis gas to heavy hydrocarbons is Fischer–Tropsch process. The process has some bottlenecks, such as hot spot formation and low degree of conversion. In this work, computational fluid dynamics technique was used to simulate conversion of synthetic gas and product distribution. Also, hot spot formation in the catalytic fixed-bed reactor was investigated in several runs. Simulation results indicated that hot spot formation occurred more likely in the early and middle part of reactor due to high reaction rates. Based on the simulation results, the temperature of hot spots increased with increase in the inlet temperature as well as pressure. Among the many CFD runs conducted, it is found that the optimal temperature and pressure for Fischer–Tropsch synthesis are 565 K and 20 bar, respectively. As it seems that the reactor shall work very well under optimal conditions, the reaction rates and catalyst duration would simultaneously be maximum .

  3. CERN: Fixed target targets

    Anon.

    1993-01-01

    Full text: While the immediate priority of CERN's research programme is to exploit to the full the world's largest accelerator, the LEP electron-positron collider and its concomitant LEP200 energy upgrade (January, page 1), CERN is also mindful of its long tradition of diversified research. Away from LEP and preparations for the LHC proton-proton collider to be built above LEP in the same 27-kilometre tunnel, CERN is also preparing for a new generation of heavy ion experiments using a new source, providing heavier ions (April 1992, page 8), with first physics expected next year. CERN's smallest accelerator, the LEAR Low Energy Antiproton Ring continues to cover a wide range of research topics, and saw a record number of hours of operation in 1992. The new ISOLDE on-line isotope separator was inaugurated last year (July, page 5) and physics is already underway. The remaining effort concentrates around fixed target experiments at the SPS synchrotron, which formed the main thrust of CERN's research during the late 1970s. With the SPS and LEAR now approaching middle age, their research future was extensively studied last year. Broadly, a vigorous SPS programme looks assured until at least the end of 1995. Decisions for the longer term future of the West Experimental Area of the SPS will have to take into account the heavy demand for test beams from work towards experiments at big colliders, both at CERN and elsewhere. The North Experimental Area is the scene of larger experiments with longer lead times. Several more years of LEAR exploitation are already in the pipeline, but for the longer term, the ambitious Superlear project for a superconducting ring (January 1992, page 7) did not catch on. Neutrino physics has a long tradition at CERN, and this continues with the preparations for two major projects, the Chorus and Nomad experiments (November 1991, page 7), to start next year in the West Area. Delicate neutrino oscillation effects could become

  4. Evaluation of effect of inlet distortion on aerodynamic performance of helium gas compressor for gas turbine high temperature reactor (GTHTR300). Contract research

    Takada, Shoji; Takizuka, Takakazu; Yan, Xing; Kurokouchi, Naohiro; Kunitomi, Kazuhiko

    2006-02-01

    Because the main pipe is connected perpendicular to the flow direction inside the distributing header in the inlet casing of the helium gas compressor design of GTHTR300, the main flow flowing into the header tends to separate from the header wall and to cause reverse flow, which increases flow resistance in the header. This phenomenon increases the total pressure loss in the header and inlet distortion, which is considered to deteriorate the aerodynamic performance of the compressor. Tests were carried out to evaluate the effects of inlet distortion on aerodynamic performance of compressor by using a 1/3-scale helium gas compressor model by varying a level of inlet distortion. Flow was injected from the wall of header to make circumferential velocities uniform before and after the reverse flow region to dissipate the separation and reverse flow. At the design point, inlet distortion was reduced by 2-3% by injection, which resulted in increasing adiabatic efficiency of blade section by 0.5%. A modified flow rate at surge point was lowered from 10.0 kg/s to 9.6 kg/s. At the same time, pressure loss of the inlet casing was reduced by 3-5 kPa, which is equivalent to adiabatic efficiency improvement around 0.8%. By setting orifice at the inlet of the inlet casing, the level of inlet distortion became 3% higher and the adiabatic efficiency of blade section became 1% higher at the design point. The modified flow rate at surge point increased from 10.6 to 10.9 kg/s. A new correlation between inlet distortion and adiabatic efficiency of blade section at the rated flow rate was derived based on compressor-in-parallel model and fitted to the test results. An overall adiabatic efficiency of full-scale compressor was predicted 90.2% based on the test results of efficiency and Reynolds number correlation, which was close to 89.7% that was predicted by test calibrated design through-flow code. (author)

  5. 77 FR 420 - Drawbridge Operation Regulation; Corson Inlet, Stathmere, NJ

    2012-01-05

    ... the course of the project, while the railings on the moveable span portion of the bridge are replaced... deviation from the regulations governing the operation of the Corson Inlet Bridge (County Route 619), across... INFORMATION: The Cape May County Bridge Commission, who owns and operates this bascule drawbridge, has...

  6. 76 FR 63840 - Drawbridge Operation Regulation; Corson Inlet, Strathmere, NJ

    2011-10-14

    ... during the project while the railings on the moveable span portion of the bridge are replaced. DATES... deviation from the regulations governing the operation of the Corson Inlet Bridge (County Route 619), at.... SUPPLEMENTARY INFORMATION: The Cape May County Bridge Commission, who owns and operates this bascule drawbridge...

  7. Validation of Helium Inlet Design for ITER Toroidal Field Coil

    Boyer, C; Hamada, K; Foussat, A; Le Rest, M; Mitchell, N; Decool, P; Savary, F; Sgobba, S; Weiss, K-P

    2014-01-01

    The ITER organization has performed design and its validation tests on a helium inlet structure for the ITER Toroidal Field (TF) coil under collaboration with CERN, KIT, and CEA-Cadarache. Detailed structural analysis was performed in order to optimize the weld shape. A fatigue resistant design on the fillet weld between the shell covers and the jacket is an important point on the helium inlet structure. A weld filler material was selected based on tensile test at liquid helium temperature after Nb$_{3}$Sn reaction heat treatment. To validate the design of the weld joint, fatigue tests at 7 K were performed using heat-treated butt weld samples. A pressure drop measurement of a helium inlet mock-up was performed by using nitrogen gas at room temperature in order to confirm uniform flow distribution and pressure drop characteristic. These tests have validated the helium inlet design. Based on the validation, Japanese and European Union domestic agencies, which have responsibilities of the TF coil procurement, a...

  8. Cross contamination in dual inlet isotope ratio mass spectrometers

    Meijer, H.A.J.; Neubert, R.E.M.; Visser, G.H.

    2000-01-01

    Since the early days of geochemical isotope ratio mass spectrometry there has always been the problem of cross contamination, i.e. the contamination of the sample gas with traces of reference gas land vice versa) in a dual inlet system and the analyzer itself. This was attributable to valve leakages

  9. Improved Hypersonic Inlet Performance Using Validated Strut Compression Designs

    Bulman, M. J.; Stout, P. W.; Fernandez, R.

    1997-01-01

    Aerojet is currently executing two Strutjet propulsion contracts: one a Rocket Based Combined Cycle (RBCC) engine for a NASA-Marshall Space Flight Center (MSFC) Advanced Reusable Transportation Technology (ARTT) program, the second a Dual Mode Ram/Scramjet engine for a USAF Wright Laboratories Storable Fuel Scramjet Flow Path Concepts program. The engines employed in both programs operate at supersonic and low hypersonic speeds and use inlets employing forebody external and sidewall compression. Aerojet has developed and validated a successful design methodology applicable to these inlet types. Design features include an integrated vehicle forebody, external side compression struts, strut sidewall and throat bleed, a throat shock trap, and variable geometry internal contraction. Computation Fluid Dynamic (CFD) predictions and test data show these inlets allow substantially increased flow turning angles over other designs. These increased flow turning angles allow shorter and lighter engines than current designs, which in turn enables higher performing vehicles with broad operating characteristics. This paper describes the designs of two different inlets evaluated by the NASA-MSFC and USAF programs, discusses the results of wind tunnel tests performed by NASA-Lewis Research Center, and provides correlations of test data with CFD predictions. Parameters of interest include low Mach number starting capability, start sensitivity as a function of back pressure at various contraction ratios, flow turning angles, strut and throat bleed effects, and pressure recovery at various Mach numbers.

  10. Boussinesq Modeling for Inlets, Harbors & Structures (Bouss-2D)

    2014-10-27

    circulation in surf and swash zone; wave-current interaction in channels and inlets; generation and impacts of infra-gravity waves on ports and...Guam, Samoa, Korea, Japan, Canada, EU countries, South Africa, Brazil, Peru, India, Indonesia , and Persian Gulf states. BMT helps the Corps evaluate

  11. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given...

  12. Physics of Acoustic Radiation from Jet Engine Inlets

    Tam, Christopher K. W.; Parrish, Sarah A.; Envia, Edmane; Chien, Eugene W.

    2012-01-01

    Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test (SDT) is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic wave to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of sound waves by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number and duct mode frequency, azimuthal mode number, and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition and in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

  13. Surface Water Quality Survey of Northern Indian River Lagoon from Sebastian Inlet to Mosquito Lagoon

    Weaver, R. J.; Webb, B. M.

    2012-12-01

    Following news of an emerging brown tide algal bloom in the northern Indian River Lagoon (IRL), researchers sought to gain insight into the surface water quality in the IRL, as well as the extent of the algae coverage. A Portable SeaKeeper from YSI, mounted to a personal watercraft-based coastal profiling system, autonomously collected and analyzed the surface water. The system operates by recording sample data every 12 seconds while continuously underway at speeds up to and greater than 50 km/hr. The researchers covered a transect that started at Sebastian Inlet and followed a zig-zag path extending up through the Haulover Canal and into the Mosquito Lagoon. The survey path covered 166.7 km, and collected 2248 samples. Along the way stops were made at water quality stations used by the Saint John's River Water Management District, so that the data collected can be incorporated into ongoing monitoring efforts. The system analyzed the surface water for dissolved oxygen, pH, chlorophyll-a, salinity, temperature, turbidity, refined fuels, and CDOM. In the two days following the lagoon survey, the inlets at Port Canaveral and Sebastian were also surveyed for tidal currents and hydrography. The IRL transect survey data recorded evidence of the southern extent of the algae bloom in both chlorophyll-a and pH levels. Visual evidence of the bloom was striking as the water in the northern IRL turned a milk chocolaty brown color. Chlorophyll-a levels in the two inlets suggested bloom activity at these locations; however this bloom was different. This oceanic bloom was a result of a persistent upwelling event along the East Florida shelf, and the color was a paler green-yellow. The near-synoptic nature of the comprehensive lagoon survey, conducted in just over 7 hours, allows researchers to obtain a better understanding of water quality in coastal lagoons. Elevated levels of salinity, temperature, and refined fuels in the northern IRL indicate a low exchange rate and absence

  14. Fixed term employment

    Durant, B.W.; Schonberner, M.J.

    1999-01-01

    A series of brief notes were included with this presentation which highlighted certain aspects of contract management. Several petroleum companies have realized the benefits of taking advantage of contract personnel to control fixed G and A, manage the impacts on their organization, contain costs, to manage termination costs, and to fill gaps in lean personnel rosters. An independent contractor was described as being someone who is self employed, often with a variety of work experiences. The tax benefits and flexibility of contractor personnel were also described. Some liability aspects of hiring an independent contractor were also reviewed. The courts have developed the following 4 tests to help determine whether an individual is an employee or an independent contractor: (1) the control test, (2) the business integration test, (3) specific result test, and (4) the economic reality test

  15. Fixed Access Network Sharing

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  16. Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound

    Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

    2012-03-30

    community as to whether strong currents produce propagating sound. (2) Analyzed data collected from a tidal turbine operating at the European Marine Energy Center to develop a profile of turbine sound and developed a framework to evaluate the acoustic effects of deploying similar devices in other locations. This framework has been applied to Public Utility District No. 1 of Snohomish Country's demonstration project in Admiralty Inlet to inform postinstallation acoustic and marine mammal monitoring plans. (3) Demonstrated passive acoustic techniques to characterize the ambient noise environment at tidal energy sites (fixed, long-term observations recommended) and characterize the sound from anthropogenic sources (drifting, short-term observations recommended). (4) Demonstrated the utility and limitations of instrumentation, including bottom mounted instrumentation packages, infrared cameras, and vessel monitoring systems. In doing so, also demonstrated how this type of comprehensive information is needed to interpret observations from each instrument (e.g., hydrophone data can be combined with vessel tracking data to evaluate the contribution of vessel sound to ambient noise). (5) Conducted a study that suggests harbor porpoise in Admiralty Inlet may be habituated to high levels of ambient noise due to omnipresent vessel traffic. The inability to detect behavioral changes associated with a high intensity source of opportunity (passenger ferry) has informed the approach for post-installation marine mammal monitoring. (6) Conducted laboratory exposure experiments of juvenile Chinook salmon and showed that exposure to a worse than worst case acoustic dose of turbine sound does not result in changes to hearing thresholds or biologically significant tissue damage. Collectively, this means that Chinook salmon may be at a relatively low risk of injury from sound produced by tidal turbines located in or near their migration path. In achieving these accomplishments, the project

  17. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    2010-07-01

    ... Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook Inlet Intrastate Air Quality Control Region (Alaska) consists of the territorial area encompassed by the boundaries... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Cook Inlet Intrastate Air Quality...

  18. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    2011-05-02

    ...] Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida AGENCY... as part of the Jupiter Inlet Lighthouse Outstanding Natural Area. DATES: Effective Date: May 2, 2011... U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural Area, and which...

  19. A Combined CFD/Characteristic Method for Prediction and Design of Hypersonic Inlet with Nose Bluntness

    Gao, Wenzhi; Li, Zhufei; Yang, Jiming

    Leading edge bluntness is widely used in hypersonic inlet design for thermal protection[1]. Detailed research of leading edge bluntness on hypersonic inlet has been concentrated on shock shape correlation[2], boundary layer flow[3], inlet performance[4], etc. It is well known that blunted noses cause detached bow shocks which generate subsonic regions around the noses and entropy layers in the flowfield.

  20. Modelling Morphological Response of Large Tidal Inlet Systems to Sea Level Rise

    Dissanayake, P.K.

    2011-01-01

    This dissertation qualitatively investigates the morphodynamic response of a large inlet system to IPCC projected relative sea level rise (RSLR). Adopted numerical approach (Delft3D) used a highly schematised model domain analogous to the Ameland inlet in the Dutch Wadden Sea. Predicted inlet

  1. Stability analysis for tidal inlets of Thuan An and Tu Hien using Escoffier diagram

    Lam, N.T.; Verhagen, H.J.; Van der Wegen, M.

    2004-01-01

    Stability analysis of tidal inlets is very important in providing knowledge on the behaviour of tidal inlet and lagoon systems. The analysis results can help to plan and manage the system effectively as well as to provide information for stability design of the inlets. This paper presents a method

  2. 36 CFR 13.320 - Preference to Cook Inlet Region, Incorporated.

    2010-07-01

    ... Region, Incorporated. 13.320 Section 13.320 Parks, Forests, and Public Property NATIONAL PARK SERVICE... to Cook Inlet Region, Incorporated. (a) The Cook Inlet Region, Incorporated (CIRI), in cooperation with village corporations within the Cook Inlet region when appropriate, will have a right of first...

  3. Evaluation of Partial Cut-out of Sacroiliac Screws From the Sacral Ala Slope via Pelvic Inlet and Outlet View.

    Zhang, Jingwei; Hamilton, Ryan; Li, Ming; Ebraheim, Nabil A; He, Xianfeng; Liu, Jiayong; Zhu, Limei

    2015-12-01

    An anatomic and radiographic study of placement of sacroiliac screws. The aim of this study was to quantitatively assess the risk of partial cut-out of sacroiliac screws from the sacral ala slope via inlet and outlet view. The partial cut-out of sacroiliac screws from the superior surface of sacral ala can jeopardize the L5 nerve root, which is difficult to identify on the pelvic inlet and outlet views. Computed tomography images of 60 patients without pelvic ring deformity or injury were used to measure the width (on inlet view) and height (on outlet view) of the sacral ala. The angle of the sacral ala slope was measured on lateral view. According to the measured parameters, the theoretical safe trajectories of screw placement were calculated using inverse trigonometric functions. Under fluoroscopic guidance, a sacroiliac screw was placed close to the midline on both inlet and outlet views, including posterosuperior, posteroinferior, anterosuperior, and anteroinferior regions to the midline. The incidence of screw partial cut-out from the superior surface of sacral ala was identified. The measured widths and heights of the sacral alas were 28.1 ± 2.8 and 29.8 ± 3.1 mm, respectively. The average angle between the superior aspect of the S1 vertebral body and the superior aspect of the sacral ala was 37.2 ± 2.5 degrees. The rate of partial cut-out of the screws from the superior surface of sacral ala slope was 12.5% (5/40) in posterosuperior, 0% (0/40) in posteroinferior, 70% (28/40) in anterosuperior, and 20% (8/40) in anteroinferior. To avoid the risk of partial cut-out from sacroiliac screw placement, more precise description should be added to the conventional description: the sacroiliac screws should be placed at the inferior half portion on outlet view and at the posterior half portion on inlet view. 4.

  4. The effects of freshwater inflow, inlet conveyance and sea level rise on the salinity regime in the Loxahatchee Estuary

    Hu, G.

    2002-01-01

    The upstream migration of salt water into the historic freshwater reaches of the Loxahatchee River is the likely cause of the altered floodplain cypress forest community along the Northwest Fork and some of its tributaries. Mangroves are replacing cypress forest and areas of mixed swamp hardwoods have reacted to different degrees to the saltwater stress. A hydrodynamic/salinity model was developed to study the influence of freshwater input, tidal inlet deepening and sea level rise on the salinity regime in the estuary. Field data analysis and model simulations indicate that the salinity condition in the estuary is sensitive to the amount of freshwater input from the watershed. During dry seasons the salt front advances into areas that were historically freshwater habitats. Historic evidence indicates that the Loxahatchee estuary was periodically closed and opened to the sea. Due to the active long shore sediment transport, the tidal inlet was probably characterized by shifting sandbars through which ran a narrow and unstable channel. Inlet dredging in the past several decades has increased the hydraulic conveyance of the inlet and the tidal influence into the estuary. The sea level record from a site in south Florida indicates that the sea level has been rising at a rate of approximately 2.3-mm per year. The rise of sea level in the past century has probably raised the mean tide level by about 23 centimeters. If the sea level rise continues as predicted, it is foreseeable that the salt front will move further upstream along with the sea level rise. Field data analysis and the preliminary model output led us to believe that the advance of seawater up the estuary is the combined effect of watershed hydrological changes, inlet deepening and sea level rise. (author)

  5. Inlet for fuel assembly having finger control rods

    Berglund, A.; Suvanto, A.; Tornblom, L.

    1975-01-01

    A nuclear reactor with vertically arranged fuel assemblies positioned on supporting members and with control rods displaceably arranged in guide tubes between the fuel rods inside the fuel assemblies is described. The supporting plate is provided with a transverse end piece with throttling means for the liquid flow which passes from below up through the supporting member and past the fuel rods in the fuel assembly. The inlets for the guide tubes for the control rods are located below the end piece and the throttling means. In this way a higher pressure prevails at the inlet to the guide tubes than above the end piece, so that a stronger flow of coolant is produced through guide tubes than through the fuel assembly. (U.S.)

  6. Predictions of Bedforms in Tidal Inlets and River Mouths

    2016-07-31

    including suggestions for reducing the burden, to the Department of Defense, Executive Service Directorate {0704-0188). Respondents should be aware...temporally varying roughness. 15. SUBJECT TERMS Bedforms, hydraulic roughness, tidal inlets, rivers 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF a...fluctuation representing local turbulence. However, once bedforms are created, the local flow around the bedforms is altered via feedback: flow is reduced in

  7. Integral Engine Inlet Particle Separator. Volume 2. Design Guide

    1975-08-01

    herein will be used in the design of integral inlet particle separators for future Army aircraft gas turbine engines. Apprupriate technical personnel...into the comprensor at some future date. 5. A typical scavenge vane design Js; shown in Figures 85 and 86. The important features of the scavenge...service passageweys, for cooling of oil, and for directing sand and air into the scroll. Orientetion of the vanes is set by collection efficiency

  8. Bedload transport in an inlet channel during a tidal cycle

    Ernstsen, V. B.; Becker, M.; Winter, C.

    2007-01-01

      Based on high-resolution swath bathymetry measurements at centimetre-scale precision conducted during a tidal cycle in a dune field in the Grådyb tidal inlet channel in the DanishWadden Sea, a simple tool to calculate bedload transport is presented. Bedload transport was related to simultaneous...... variations in grain-size composition of the mobilised sediment should be taken into account by sediment transport formulae....

  9. Long-term Morphological Modeling at Coastal Inlets

    2015-05-15

    that of Humboldt Bay, CA. The model reproduces reasonably well several geomorphic and hydrodynamic features of the inlet at Humboldt Bay. The...geometries, and model setup (e.g., sediment transport formulas) to investigate the controlling geomorphic parameters and the applicability of the CMS...2015 9 The model reproduces the general geomorphic features of Humboldt Bay. The ebb shoal volume is in the lower range of the estimated amount

  10. Reconstruction of paleo-inlet dynamics using sedimentologic analyses, geomorphic features, and benthic foraminiferal assemblages: former ephemeral inlets of Cedar Island, Virginia, USA

    McBride, R.; Wood, E. T.

    2017-12-01

    Cedar Island, VA is a low-profile, washover-dominated barrier island that has breached at least three times in the past sixty years. Cedar Island Inlet, a former wave-dominated tidal inlet, was open for the following time periods: 1) 1956-1962, 2) 1992-1997, and 3) 1998-2007. Air photos, satellite imagery, and geomorphic features (i.e., relict flood tidal deltas, recurved-spit ridges) record the spatial and temporal extent of the three ephemeral inlets. Based on three sediment vibracores, benthic foraminiferal and sedimentologic analyses offer high resolution insights of inlet dynamics and lifecycle evolution. Four foraminiferal biofacies are completely dominated by Elphidium excavatum (54-100%) and contain unique assemblages of accessory species based on cluster analyses: tidal inlet floor (low abundance estuarine and shelf species; 23% Haynesina germanica); flood tidal delta/inlet fill (high abundance estuarine and shelf species; 2% Buccella frigida, 2% Ammonia parkinsoniana, and 2% Haynesina germanica); high-energy inlet fill (low abundance, low diversity shelf species; 9% Elphidium gunteri); and washover/beach/aeolian (low abundance, predominantly shelf species; 3% Buccella frigida and 3% Ammonia parkinsoniana). The estuarine biofacies is barren of all foraminifera. Grain size trends indicate a first order coarsening-upward succession with second order coarsening- and fining-upwards packages in inlet throat deposits, while a first order fining-upward succession is observed in flood tidal delta deposits with two second order coarsening-upward packages in the proximal flood tidal delta. Contrary to typical wave-dominated tidal inlets that open, migrate laterally in the direction of net longshore transport, and close, the 1998-2007 tidal inlet, and possibly the 1956-1962 inlet, migrated laterally and rotated, whereas the 1992-1997 inlet remained stationary and did not rotate. In the vicinity of the vibracores, preserved deposits are attributed to the 1956-1962 and

  11. Exchange inlet optimization by genetic algorithm for improved RBCC performance

    Chorkawy, G.; Etele, J.

    2017-09-01

    A genetic algorithm based on real parameter representation using a variable selection pressure and variable probability of mutation is used to optimize an annular air breathing rocket inlet called the Exchange Inlet. A rapid and accurate design method which provides estimates for air breathing, mixing, and isentropic flow performance is used as the engine of the optimization routine. Comparison to detailed numerical simulations show that the design method yields desired exit Mach numbers to within approximately 1% over 75% of the annular exit area and predicts entrained air massflows to between 1% and 9% of numerically simulated values depending on the flight condition. Optimum designs are shown to be obtained within approximately 8000 fitness function evaluations in a search space on the order of 106. The method is also shown to be able to identify beneficial values for particular alleles when they exist while showing the ability to handle cases where physical and aphysical designs co-exist at particular values of a subset of alleles within a gene. For an air breathing engine based on a hydrogen fuelled rocket an exchange inlet is designed which yields a predicted air entrainment ratio within 95% of the theoretical maximum.

  12. Characterizing Interferences in an NOy Thermal Dissociation Inlet

    Womack, C.; Veres, P. R.; Brock, C. A.; Neuman, J. A.; Eilerman, S. J.; Zarzana, K. J.; Dube, W. P.; Wild, R. J.; Wooldridge, P. J.; Cohen, R. C.; Brown, S. S.

    2016-12-01

    Nitrogen oxides (NOx = NO and NO2) are emitted into the troposphere by various anthropogenic and natural sources, and contribute to increased levels of ambient ozone. Reactive nitrogen species (NOy), which include nitric acid, peroxy acetyl and organic nitrates, and other species, serve as reservoirs and sinks for NOx, thus influencing O3 production. Their detection is therefore critical to understanding ozone chemistry. However, accurate measurements of NOy have proven to be difficult to obtain, and measurements of total NOy sometimes do not agree with the sum of measurements of its individual components. In recent years, quartz thermal dissociation (TD) inlets have been used to thermally convert all NOy species to NO2, followed by detection by techniques such as laser induced fluorescence (LIF) or cavity ringdown spectroscopy (CRDS). Here we discuss recent work in characterizing the NOy channel of our four-channel TD-CRDS instrument. In particular, we have examined the thermal conversion efficiency of several representative NOy species under a range of experimental conditions. We find that under certain conditions, the conversion efficiency is sensitive to inlet residence time and to the concentration of other trace gases found in ambient sampling, such as ozone. We also report the thermal dissociation curves of N2O5 and ammonium nitrate aerosol, and discuss the interferences observed when ammonia and ozone are co-sampled in the inlet.

  13. Thermography of the New River Inlet plume and nearshore currents

    Chickadel, C.; Jessup, A.

    2012-12-01

    As part of the DARLA and RIVET experiments, thermal imaging systems mounted on a tower and in an airplane captured water flow in the New River Inlet, NC, USA. Kilometer-scale, airborne thermal imagery of the inlet details the ebb flow of the estuarine plume water mixing with ocean water. Multiple fronts, corresponding to the preferred channels through the ebb tidal delta, are imaged in the aerial data. A series of internal fronts suggest discreet sources of the tidal plume that vary with time. Focused thermal measurements made from a tower on the south side of the inlet viewed an area within a radius of a few hundred meters. Sub-meter resolution video from the tower revealed fine-scale flow features and the interaction of tidal exchange and wave-forced surfzone currents. Using the tower and airborne thermal image data we plan to provide geophysical information to compare with numerical models and in situ measurements made by other investigators. From the overflights, we will map the spatial and temporal extent of the estuarine plume to correlate with tidal phase and local wind conditions. From the tower data, we will investigate the structure of the nearshore flow using a thermal particle image velocimetry (PIV) technique, which is based on tracking motion of the surface temperature patterns. Long term variability of the mean and turbulent two-dimensional PIV currents will be correlated to local wave, tidal, and wind forcing parameters.

  14. Impact of inlet coherent motions on compressor performance

    Forlese, Jacopo; Spoleti, Giovanni

    2017-08-01

    Automotive engine induction systems may be characterized by significant flow angularity and total pressure distortion at the compressor inlet. The impact of the swirl on compressor performance should be quantified to guide the design of the induction systems. In diesel engines, the presence of a valve for flow reduction and control of low pressure EGR recirculation could generate coherent motion and influence the performance of the compressor. Starting from experimental map, the compressor speed-lines have been simulated using a 3D CFD commercial code imposing different concept motion at the inlet. The swirl intensity, the direction and the number of vortices have been imposed in order to taking into account some combinations. Finally, a merit function has been defined to evaluate the performance of the compressor with the defined swirl concepts. The aim of the current work is to obtain an indication on the effect of a swirling motion at the compressor inlet on the engine performance and provide a guideline to the induction system design.

  15. Computational Fluid Dynamics Analysis Method Developed for Rocket-Based Combined Cycle Engine Inlet

    1997-01-01

    Renewed interest in hypersonic propulsion systems has led to research programs investigating combined cycle engines that are designed to operate efficiently across the flight regime. The Rocket-Based Combined Cycle Engine is a propulsion system under development at the NASA Lewis Research Center. This engine integrates a high specific impulse, low thrust-to-weight, airbreathing engine with a low-impulse, high thrust-to-weight rocket. From takeoff to Mach 2.5, the engine operates as an air-augmented rocket. At Mach 2.5, the engine becomes a dual-mode ramjet; and beyond Mach 8, the rocket is turned back on. One Rocket-Based Combined Cycle Engine variation known as the "Strut-Jet" concept is being investigated jointly by NASA Lewis, the U.S. Air Force, Gencorp Aerojet, General Applied Science Labs (GASL), and Lockheed Martin Corporation. Work thus far has included wind tunnel experiments and computational fluid dynamics (CFD) investigations with the NPARC code. The CFD method was initiated by modeling the geometry of the Strut-Jet with the GRIDGEN structured grid generator. Grids representing a subscale inlet model and the full-scale demonstrator geometry were constructed. These grids modeled one-half of the symmetric inlet flow path, including the precompression plate, diverter, center duct, side duct, and combustor. After the grid generation, full Navier-Stokes flow simulations were conducted with the NPARC Navier-Stokes code. The Chien low-Reynolds-number k-e turbulence model was employed to simulate the high-speed turbulent flow. Finally, the CFD solutions were postprocessed with a Fortran code. This code provided wall static pressure distributions, pitot pressure distributions, mass flow rates, and internal drag. These results were compared with experimental data from a subscale inlet test for code validation; then they were used to help evaluate the demonstrator engine net thrust.

  16. Fixed points of quantum gravity

    Litim, D F

    2003-01-01

    Euclidean quantum gravity is studied with renormalisation group methods. Analytical results for a non-trivial ultraviolet fixed point are found for arbitrary dimensions and gauge fixing parameter in the Einstein-Hilbert truncation. Implications for quantum gravity in four dimensions are discussed.

  17. Experimental Investigation of a Large-Scale Low-Boom Inlet Concept

    Hirt, Stefanie M.; Chima, Rodrick V.; Vyas, Manan A.; Wayman, Thomas R.; Conners, Timothy R.; Reger, Robert W.

    2011-01-01

    A large-scale low-boom inlet concept was tested in the NASA Glenn Research Center 8- x 6- foot Supersonic Wind Tunnel. The purpose of this test was to assess inlet performance, stability and operability at various Mach numbers and angles of attack. During this effort, two models were tested: a dual stream inlet designed to mimic potential aircraft flight hardware integrating a high-flow bypass stream; and a single stream inlet designed to study a configuration with a zero-degree external cowl angle and to permit surface visualization of the vortex generator flow on the internal centerbody surface. During the course of the test, the low-boom inlet concept was demonstrated to have high recovery, excellent buzz margin, and high operability. This paper will provide an overview of the setup, show a brief comparison of the dual stream and single stream inlet results, and examine the dual stream inlet characteristics.

  18. Reflooding Experiment on BETA Test Loop: The Effects of Inlet Temperature on the Rewetting Velocity

    Khairul H; Anhar R Antariksawan; Edy Sumarno; Kiswanta; Giarno; Joko P; Ismu Handoyo

    2003-01-01

    Loss of Coolant Accident (LOCA) on Nuclear Reactor Plant is an important topic because this condition is a severe accident that can be postulated. The phenomenon of LOCA on Pressurized Water Reactor (PWR) can be divided in three stages, e.g.: blowdown, refill and reflood. In the view of Emergency Coolant System evaluation, the reflood is the most important stage. In this stage, an injection of emergency water coolant must be done in a way that the core can be flooded and the overheating can be avoid. The experiment of rewetting on BETA Test Loop had been conducted. The experiment using one heated rod of the test section to study effects of inlet temperature on the wetting velocity. Results of the series of experiments on 2,5 lt/min flow rate and variable of temperature : 28 o C, 38 o C, 50 o C, 58 o C it was noticed that for 58 o C inlet temperature of test section and 572 o C rod temperature the rewetting phenomenon has been observed. The time of refill was 32.81 sec and time of rewetting was 42.87 sec. (author)

  19. Flow control in axial fan inlet guide vanes by synthetic jets

    Wurst P.

    2013-04-01

    Full Text Available Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV, rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz – 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 – 12 mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  20. Flow control in axial fan inlet guide vanes by synthetic jets

    Cyrus, V.; Trávníček, Z.; Wurst, P.; Kordík, J.

    2013-04-01

    Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV), rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz - 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 - 12) mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  1. Inlet effects on roll-wave development in shallow turbulent open-channel flows

    Campomaggiore Francesca

    2016-03-01

    Full Text Available The present work investigates the effect of the flow profile induced by an inlet condition on the roll-wave evolution in turbulent clear-water flows. The study employs theoretical and numerical analyses. Firstly, the influence of the inlet condition on the spatial evolution of a single perturbation in a hypercritical flow is examined through the expansion near a wavefront analysis. The results show that an accelerated unperturbed profile reduces the disturbance spatial growth. A decelerated profile causes an increase. The effect of the flow profile on the spatial evolution of roll-wave trains is then numerically investigated solving the Saint Venant equations with a second-order Runge-Kutta Total Variation Diminishing (TVD Finite Volume scheme. The numerical simulations comply with the analytical results for the initial and transition phases of the roll-wave development. The unperturbed profile influences even the roll-waves statistical characteristics in the final stage, with a more evident effect in case of accelerated profiles. The influence of the flow profile should be therefore accounted for in the formulation of predictive criteria for roll-waves appearance based on the estimation of the disturbance spatial growth rate.

  2. Integration of steam injection and inlet air cooling for a gas turbine generation system

    Wang, F.J.; Chiou, J.S.

    2004-01-01

    The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 deg. C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in the power generation system for enhancing power generation capacity and efficiency. Two well-proven techniques, namely steam injection gas turbine (STIG) and inlet air cooling (IAC) are very effective features that can use the generated steam to improve the power generation capacity and efficiency. Since the energy level of the generated steam needed for steam injection is different from that needed by an absorption chiller to cool the inlet air, a proper arrangement is required to implement both the STIG and the IAC features into the simple cycle GENSET. In this study, a computer code was developed to simulate a Tai power's Frame 7B simple cycle GENSET. Under the condition of local summer weather, the benefits obtained from the system implementing both STIG and IAC features are more than a 70% boost in power and 20.4% improvement in heat rate

  3. Velocity profile of water vapor inside a cavity with two axial inlets and two outlets

    Guadarrama-Cetina, José; Ruiz Chavarría, Gerardo

    2014-03-01

    To study the dynamics of Breath Figure phenomenon, a control of both the rate of flow and temperature of water vapor is required. The experimental setup widely used is a non hermetically closed chamber with cylindrical geometry and axial inlets and outlets. In this work we present measurements in a cylindrical chamber with diameter 10 cm and 1.5 cm height, keeping a constant temperature (10 °C). We are focused in the velocity field when a gradient of the temperatures is produced between the base plate and the vapor. With a flux of water vapor of 250 mil/min at room temperature (21 °C), the Reynolds number measured in one inlet is 755. Otherwise, the temperatures of water vapor varies from 21 to 40 °C. The velocity profile is obtained by hot wire anemometry. We identify the stagnations and the possibly instabilities regions for an empty plate and with a well defined shape obstacle as a fashion sample. Facultad de Ciencias, UNAM.

  4. Unstart phenomena induced by flow choking in scramjet inlet-isolators

    Im, Seong-kyun; Do, Hyungrok

    2018-02-01

    A review of recent research outcomes in downstream flow choking-driven unstart is presented. Unstart is a flow phenomenon at the inlet that severely reduces the air mass flow rate through the engine, causing a loss of thrust and considerable transient mechanical loading. Therefore, unstart in a scramjet engine crucially affects the design and the operation range of hypersonic vehicles. Downstream flow choking is known to be one of the major mechanisms inducing inlet unstart, as confirmed by recent scramjet-powered flight tests. The current paper examines recent research progress in identifying flow choking mechanisms that trigger unstart. Three different flow choking mechanisms are discussed: flow blockage, mass addition, and heat release from combustion reactions. Current research outcomes on the characteristic of unstarting flows, such as transient and quasi-steady motions, are reviewed for each flow choking mechanism. The characteristics of unstarted flows are described including Buzzing phenomena and oscillatory motions of unstarted shockwaves. Then, the state-of-the-art methods to predict, detect, and control unstart are presented. The review suggests that further investigations with high-enthalpy ground facilities will aid understanding of heat release-driven unstart.

  5. An Investigation of the Drag and Pressure Recovery of a Submerged Inlet and a Nose Inlet in the Transonic Flight Range with Free-fall Models

    Selna, James; Schlaff, Bernard A

    1951-01-01

    The drag and pressure recovery of an NACA submerged-inlet model and an NACA series I nose-inlet model were investigated in the transonic flight range. The tests were conducted over a mass-flow-ratio range of 0.4 to 0.8 and a Mach number range of about 0.8 to 1.10 employing large-scale recoverable free-fall models. The results indicate that the Mach number of drag divergence of the inlet models was about the same as that of a basic model without inlets. The external drag coefficients of the nose-inlet model were less than those of the submerged-inlet model throughout the test range. The difference in drag coefficient based on the maximum cross-sectional area of the models was about 0.02 at supersonic speeds and about 0.015 at subsonic speeds. For a hypothetical airplane with a ratio of maximum fuselage cross-sectional area to wing area of 0.06, the difference in airplane drag coefficient would be relatively small, about 0.0012 at supersonic speeds and about 0.0009 at subsonic speeds. Additional drag comparisons between the two inlet models are made considering inlet incremental and additive drag.

  6. Chronostratigraphic Analysis of Geomorphic Features within the Former Sinepuxent Inlet: A Wave-Dominated Tidal Inlet along Assateague Island, MD, USA

    Seminack, C.; McBride, R.; Petruny, L. M.

    2017-12-01

    The former Sinepuxent Inlet, located along the mixed-energy, wave-dominated Assateague Island, MD-VA, USA, contains some of the most robust recurved-spit ridges along the span of the barrier island. In addition, this former tidal inlet exhibits a poorly developed flood-tidal delta containing at least two sets of curvilinear ridges known as "washarounds". Historical maps and nautical charts indicate that the former Sinepuxent Inlet was open from 1755 to 1832. However, previous studies conducted at the former Sinepuxent Inlet hypothesized that the site was exposed to episodic breaching events because of the extensive width of the former inlet throat, constrained by the northern and southern recurved-spit ridges. A total of 16 sediment cores, 10 optically stimulated luminescence (OSL) samples, and three 14C samples (mixed benthic foraminifera and eastern mud snail [Ilyanassa obsolete]) were collected from the former Sinepuxent Inlet to place morphostratigraphic units into a chronological context. Six OSL samples were collected from the northern and southern recurved-spit ridges at mean sea level (MSL) to constrain genesis ages. Southern recurved-spit ages varied more than their northern counterparts, ranging from 1640 to 1990 AD. The northern recurved-spit ridges varied in age from 1770 to 1900 AD. Two OSL samples collected from flood-tidal delta ridges yielded ages from 1680 to 2000 AD. In addition, two 14C samples collected at 128 and 101 cm below MSL within the inlet throat yielded ages between 1720 and post-1950 AD. Ultimately, these dates overlap with the inlet activity phase as indicated in historical documents. Conversely, two OSL samples (155 and 201 cm below MSL) and one 14C sample (134 cm below MSL) collected from the inlet throat returned ages between 760 and 1465 AD. The contrast in ages between the older inlet throat and subaerial ridge samples supports the hypothesis that the former Sinepuxent Inlet was reactivated numerous times. Thus, the three age

  7. Titanium Aluminide Scramjet Inlet Flap Subelement Benchmark Tested

    Krause, David L.; Draper, Susan L.

    2005-01-01

    A subelement-level ultimate strength test was completed successfully at the NASA Glenn Research Center (http://www.nasa.gov/glenn/) on a large gamma titanium aluminide (TiAl) inlet flap demonstration piece. The test subjected the part to prototypical stress conditions by using unique fixtures that allowed both loading and support points to be located remote to the part itself (see the photograph). The resulting configuration produced shear, moment, and the consequent stress topology proportional to the design point. The test was conducted at room temperature, a harsh condition for the material because of reduced available ductility. Still, the peak experimental load-carrying capability exceeded original predictions.

  8. Temperature-programmed desorption for membrane inlet mass spectrometry

    Ketola, R.A.; Grøn, C.; Lauritsen, F.R.

    1998-01-01

    We present a novel technique for analyzing volatile organic compounds in air samples using a solid adsorbent together with temperature-programmed desorption and subsequent detection by membrane inlet mass spectrometry (TPD-MIMS). The new system has the advantage of a fast separation of compounds...... to diffuse through the membrane into the mass spectrometer in a few seconds. In this fashion we could completely separate many similar volatile compounds, for example toluene from xylene and trichloroethene from tetrachloroethene. Typical detection limits were at low or sub-nanogram levels, the dynamic range...

  9. Experimental and numerical analysis on the effect of inlet distortion on the performance of a centrifugal fan with a mixing chamber

    Ding, Liang; Wang, Tong; Yang, Bo; Gu, Chuangang [Shanghai Jiao Tong University, Shanghai (China)

    2013-02-15

    Inlet flow distortions, which are caused by fluid mixing, cause a significant deterioration in fan performance. An experimental test rig for an industrial fan with dual inlets and a mixing chamber was constructed. The flow fields in the mixing chamber of the fan were numerically investigated. Consequently, impact parameters, including the length of the mixing chamber (100, 200, and 300 mm) and the mass flow rate ratio (1 to 10), as well as their effects on fan performance, were discussed. A generalized formula considering the Reynolds number, hydraulic diameter, and mixing length was proposed to predict the pressure drop in dual inlets. Results show that the efficiency of and pressure in the fan decreased by 6.5% and 203 Pa, respectively, under mixing inlet condition. Optimum fan performance is achieved at a flow rate ratio of 5 under the same mass flow rate. The increase in the flow rate ratio kept the fan performance almost constant. At the design stage, fan performance and pressure decrease by an average of 2% and 70 Pa in increments of 100 mm mixing length, respectively. The results presented in this paper provide a basis in the design optimization of mixing structures.

  10. Experimental and numerical analysis on the effect of inlet distortion on the performance of a centrifugal fan with a mixing chamber

    Ding, Liang; Wang, Tong; Yang, Bo; Gu, Chuangang

    2013-01-01

    Inlet flow distortions, which are caused by fluid mixing, cause a significant deterioration in fan performance. An experimental test rig for an industrial fan with dual inlets and a mixing chamber was constructed. The flow fields in the mixing chamber of the fan were numerically investigated. Consequently, impact parameters, including the length of the mixing chamber (100, 200, and 300 mm) and the mass flow rate ratio (1 to 10), as well as their effects on fan performance, were discussed. A generalized formula considering the Reynolds number, hydraulic diameter, and mixing length was proposed to predict the pressure drop in dual inlets. Results show that the efficiency of and pressure in the fan decreased by 6.5% and 203 Pa, respectively, under mixing inlet condition. Optimum fan performance is achieved at a flow rate ratio of 5 under the same mass flow rate. The increase in the flow rate ratio kept the fan performance almost constant. At the design stage, fan performance and pressure decrease by an average of 2% and 70 Pa in increments of 100 mm mixing length, respectively. The results presented in this paper provide a basis in the design optimization of mixing structures.

  11. National Radiological Fixed Lab Data

    U.S. Environmental Protection Agency — The National Radiological Fixed Laboratory Data Asset includes data produced in support of various clients such as other EPA offices, EPA Regional programs, DOE,...

  12. Can mushrooms fix atmospheric nitrogen?

    Unknown

    Introduction. Rhizobium is a genus of symbiotic N2-fixing soil bacteria that induce ... To produce biofilm cultures, a 2 × 2 cm yeast manitol agar. (YMA) slab was .... determination of antibiotic susceptibilities of bacterial biofilms;. J. Clin. Microbiol.

  13. Elevated Fixed Platform Test Facility

    Federal Laboratory Consortium — The Elevated Fixed Platform (EFP) is a helicopter recovery test facility located at Lakehurst, NJ. It consists of a 60 by 85 foot steel and concrete deck built atop...

  14. 31 CFR 359.14 - How are composite rates determined?

    2010-07-01

    ... composite interest rates.): Composite rate = {(Fixed rate ÷ 2) + Semiannual inflation rate + [Semiannual inflation rate × (Fixed rate ÷ 2)]} × 2. 2 2 Example for I bonds issued May 2002-October 2002: Fixed rate = 2.00% Inflation rate = 0.28% Composite rate = [0.0200 ÷ 2 + 0.0028 + (0.0028 × 0.0200 ÷ 2)] ×2...

  15. THE MAIN QUESTION OF FIXED ASSETS

    Kogan A. B.

    2015-03-01

    Full Text Available The article deals with the methods of selecting the best type of fixed assets (real investment. Explore the current situation where the investor has to compare the different-parametrical alternatives (DPA. The DPA are the fixed assets which have similar functions, but different in price, durability and periodic effects. In the general case the DPA are the investment projects which have different amounts of investment, accounting periods and net cash flow. Net present value (NPV and internal rate of return (IRR are criticized. The author describes his indicator «speed index of unit value increase» (IS. The author proves on numerical examples that the economy, the subjects of which use IS instead of NPV and IRR, has accelerated the pace of development.

  16. Experimental and numerical investigations of BWR fuel bundle inlet flow

    Hoashi, E; Morooka, S; Ishitori, T; Komita, H; Endo, T; Honda, H; Yamamoto, T; Kato, T; Kawamura, S

    2009-01-01

    We have been studying the mechanism of the flow pattern near the fuel bundle inlet of BWR using both flow visualization test and computational fluid dynamics (CFD) simulation. In the visualization test, both single- and multi-bundle test sections were used. The former test section includes only a corner orifice facing two support beams and the latter simulates 16 bundles surrounded by four beams. An observation window is set on the side of the walls imitating the support beams upstream of the orifices in both test sections. In the CFD simulation, as well as the visualization test, the single-bundle model is composed of one bundle with a corner orifice and the multi-bundle model is a 1/4 cut of the test section that includes 4 bundles with the following four orifices: a corner orifice facing the corner of the two neighboring support beams, a center orifice at the opposite side from the corner orifice, and two side orifices. Twin-vortices were observed just upstream of the corner orifice in the multi-bundle test as well as the single-bundle test. A single-vortex and a vortex filament were observed at the side orifice inlet and no vortex was observed at the center orifice. These flow patterns were also predicted in the CFD simulation using Reynolds Stress Model as a turbulent model and the results were in good agreement with the test results mentioned above. (author)

  17. 20% inlet header break analysis of Advanced Heavy Water Reactor

    Srivastava, A.; Gupta, S.K.; Venkat Raj, V.; Singh, R.; Iyer, K.

    2001-01-01

    The proposed Advanced Heavy Water Reactor (AHWR) is a 750 MWt vertical pressure tube type boiling light water cooled and heavy water moderated reactor. A passive design feature of this reactor is that the heat removal is achieved through natural circulation of primary coolant at all power levels, with no primary coolant pumps. Loss of coolant due to failure of inlet header results in depressurization of primary heat transport (PHT) system and containment pressure rise. Depressurization activates various protective and engineered safety systems like reactor trip, isolation condenser and advanced accumulator, limiting the consequences of the event. This paper discusses the thermal hydraulic transient analysis for evaluating the safety of the reactor, following 20% inlet header break using RELAP5/MOD3.2. For the analysis, the system is discretized appropriately to simulate possible flow reversal in one of the core paths during the transient. Various modeling aspects are discussed in this paper and predictions are made for different parameters like pressure, temperature, steam quality and flow in different parts of the Primary Heat Transport (PHT) system. Flow and energy discharges into the containment are also estimated for use in containment analysis. (author)

  18. Flow distribution in the inlet plenum of steam generator

    Khadamakar, H.P.; Patwardhan, A.W.; Padmakumar, G.; Vaidyanathan, G.

    2011-01-01

    Highlights: → Various flow distribution devices have been studied to make the flow distribution uniform in axial as well as tangential direction. → Experiments were performed using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV). → CFD modeling has been carried out to give more insights. → Various flow distribution devices have been compared. - Abstract: The flow distribution in a 1/5th and 1/8th scale models of inlet plenum of steam generator (SG) has been studied by a combination of experiments and Computational Fluid Dynamics (CFD) simulations. The distribution of liquid sodium in the inlet plenum of the SG strongly affects the thermal as well as mechanical performance of the steam generator. Various flow distribution devices have been used to make the flow distribution uniform in axial as well as tangential direction in the window region. Experiments have been conducted to measure the radial velocity distribution using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV) under a variety of conditions. CFD modeling has been carried out for various configurations to give more insight into the flow distribution phenomena. The various flow distribution devices have been compared on the basis of a non-uniformity index parameter.

  19. 29 CFR 778.114 - Fixed salary for fluctuating hours.

    2010-07-01

    ..., whatever their number, rather than for working 40 hours or some other fixed weekly work period, such a... compensation to the employee at a rate not less than the applicable minimum wage rate for every hour worked in..., in addition to such salary, for all overtime hours worked at a rate not less than one-half his...

  20. Fixed-Time Stability of the Hydraulic Turbine Governing System

    Caoyuan Ma

    2018-01-01

    Full Text Available This paper studies the problem of fixed-time stability of hydraulic turbine governing system with the elastic water hammer nonlinear model. To control and improve the quality of hydraulic turbine governing system, a new fixed-time control strategy is proposed, which can stabilize the water turbine governing system within a fixed time. Compared with the finite-time control strategy where the convergence rate depends on the initial state, the settling time of the fixed-time control scheme can be adjusted to the required value regardless of the initial conditions. Finally, we numerically show that the fixed-time control is more effective than and superior to the finite-time control.

  1. The Effects of Inlet Box Aerodynamics on the Mechanical Performance of a Variable Pitch in Motion Fan

    A. G. Sheard

    2012-01-01

    Full Text Available This paper describes research involving an in-service failure of a “variable pitch in motion” fan’s blade bearing. Variable pitch in motion fans rotate at a constant speed, with the changing blade angle varying the load. A pitch-change mechanism facilitates the change in blade angle. A blade bearing supports each blade enabling it to rotate. The author observed that as the fan aerodynamic stage loading progressively increased, so did the rate of blade-bearing wear. The reported research addressed two separate, but linked, needs. First, the ongoing need to increase fan pressure development capability required an increase in fan loading. This increase was within the context of an erosive operating regime which systematically reduced fan pressure development capability. The second need was to identify the root cause of blade-bearing failures. The author addressed the linked needs using a computational analysis, improving the rotor inflow aerodynamic characteristics through an analysis of the inlet box and design of inlet guide vanes to control flow nonuniformities at the fan inlet. The results of the improvement facilitated both an increase in fan-pressure-developing capability and identification of the root cause of the blade-bearing failures.

  2. Impact of inlet fogging and fuels on power and efficiency of gas turbine plants

    Basha Mehaboob

    2013-01-01

    Full Text Available A computational study to assess the performance of different gas turbine power plant configurations is presented in this paper. The work includes the effect of humidity, ambient inlet air temperature and types of fuels on gas turbine plant configurations with and without fogger unit. Investigation also covers economic analysis and effect of fuels on emissions. GT frames of various sizes/ratings are being used in gas turbine power plants in Saudi Arabia. 20 MWe GE 5271RA, 40 MWe GE-6561B and 70 MWe GE-6101FA frames are selected for the present study. Fogger units with maximum mass flow rate of 2 kg/s are considered for the present analysis. Reverse Osmosis unit of capacity 4 kg/s supplies required water to the fogger units. GT PRO software has been used for carrying out the analysis including; net plant output and net efficiency, break even electricity price and break even fuel LHV price etc., for a given location of Saudi Arabia. The relative humidity and temperature have been varied from 30 to 45 % and from 80 to 100° F, respectively. Fuels considered in the study are natural gas, diesel and heavy bunker oil. Simulated gas turbine plant output from GT PRO has been validated against an existing gas turbine plant output. It has been observed that the simulated plant output is less than the existing gas turbine plant output by 5%. Results show that variation of humidity does not affect the gas turbine performance appreciably for all types of fuels. For a decrease of inlet air temperature by 10 °F, net plant output and efficiency have been found to increase by 5 and 2 %, respectively for all fuels, for GT only situation. However, for GT with Fogger scenario, for a decrease of inlet air temperature by 10 °F, net plant output and efficiency have been found to further increase by 3.2 and 1.2 %, respectively for all fuels. For all GT frames with fogger, the net plant output and efficiency are relatively higher as compared to GT only case for all

  3. Modeling Interactions between Backbarrier Marshes, Tidal Inlets, Ebb-deltas, and Adjacent Barriers Exposed to Rising Sea Levels

    Hanegan, K.; Georgiou, I. Y.; FitzGerald, D.

    2016-02-01

    Along barrier island chains, tidal exchange between the backbarrier and the coastal ocean supports unique saltwater and brackish ecosystems and is responsible for exporting sediment and nutrients to the surrounding coast. Tidal prism, basement controls, and wave and tidal energy dictate the size and number of tidal inlets and the volume of sand sequestered in ebb-tidal deltas. The inlet tidal prism is a function of bay area, tidal range, and secondary controls, including flow inertia, basinal hypsometry, and frictional factors. Sea- level rise (SLR) is threatening coastal environments, causing mainland flooding, changes in sediment supply, and conversion of wetlands and tidal flats to open water. These factors are impacting basinal hypsometry and increasing open water area, resulting in enlarging tidal prisms, increased dimensions of tidal inlets and ebb-tidal deltas, and erosion along adjacent barrier shorelines. Although the effects of SLR on coastal morphology are difficult to study by field observations alone, physics-based numerical models provide a sophisticated means of analyzing coastal processes over decadal time-scales and linking process causation to long term development. Here, we use a numerical model that includes relevant features in the barrier/tidal basin system, linking back-barrier marsh degradation, inlet expansion, and ebb-delta growth to barrier erosion through long-term hydrodynamic and morphology simulations. Sediment exchange and process interactions are investigated using an idealized domain resembling backbarrier basins of mixed energy coasts so that the sensitivity to varying SLR rates, interior marsh loss, sediment supply, and hydrodynamic controls can be more easily analyzed. Model runs explore these processes over geologic time scales, demonstrating the vulnerability of backbarrier systems to projected SLR and marsh loss. Results demonstrate the links between changing basin morphology and shoreface sedimentation patterns that initiate

  4. Calculation of external-internal flow fields for mixed-compression inlets

    Chyu, W. J.; Kawamura, T.; Bencze, D. P.

    1987-01-01

    Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

  5. Oregon inlet: Hydrodynamics, volumetric flux and implications for larval fish transport

    Nichols, C.R. [National Oceanic and Atmospheric Administration, Silver Springs, MD (United States); Pietrafesa, L.J. [North Carolina State Univ., Raleigh, NC (United States). Department of Marine, Earth and Atmospheric Sciences

    1997-05-01

    The temporal response of Oregon Inlet currents to atmospheric forcing and sea level fluctuations is analyzed using time and frequency domain analysis. Temporally persistent and spatially extensive ebb and flood events are identified using data sets from both within and outside of Oregon Inlet. Prism estimates are made to generate a time series of volumetric flux of water transported through the inlet. Water masses flooding into the Pamlico Sound via Oregon Inlet are identified in temperature (T) and salinity (S) space to determine their source of origin. Correlations are examined between the atmospheric wind field, the main axial slope of the inlet`s water level, inlet flow and T, S properties. Synoptic scale atmospheric wind events are found to dramatically and directly affect the transport of water towards (away from) the inlet on the ocean side, in concert with the contemporaneous transport away from (towards) the inlet on the estuary side, and a subsequent flooding into (out of) the estuary via Oregon Inlet. Thus, while astronomical tidal flooding and ebbing events are shown to be one-sided as coastal waters either set-up or set-down, synoptic scale wind events are shown to be manifested as a two-sided in-phase response set-up and set-down inside and outside the inlet, and thus are extremely effective in driving currents through the inlet. These subinertial frequency flood events are believed to be essential for both the recruitment and subsequent retention of estuarine dependent larval fish from the coastal ocean into Pamlico Sound. Year class strength of these finish may be determined annually by the relative strength and timing of these climatological wind events.

  6. Dynamic analysis of CO₂ labeling and cell respiration using membrane-inlet mass spectrometry.

    Yang, Tae Hoon

    2014-01-01

    Here, we introduce a mass spectrometry-based analytical method and relevant technical details for dynamic cell respiration and CO2 labeling analysis. Such measurements can be utilized as additional information and constraints for model-based (13)C metabolic flux analysis. Dissolved dynamics of oxygen consumption and CO2 mass isotopomer evolution from (13)C-labeled tracer substrates through different cellular processes can be precisely measured on-line using a miniaturized reactor system equipped with a membrane-inlet mass spectrometer. The corresponding specific rates of physiologically relevant gases and CO2 mass isotopomers can be quantified within a short-term range based on the liquid-phase dynamics of dissolved fermentation gases.

  7. The effect of inlet flow oscillations on reflooding of a tubular test section

    Oh, S.; Banerjee, S.; Yadigaroglu, G.

    1983-01-01

    The reflooding of a vertical channel under oscillatory inlet flow conditions has been investigated experimentally. Compared to constant injection, oscillations always increase the liquid carryover in the early stages of reflooding. As reflooding progresses, the enhancement diminishes. The crossover point roughly coincides with saturation of the liquid at the quench front (QF). The higher liquid carryover at the beginning increases downstream heat transfer and speeds up QF propagation. But this higher liquid carryover, in turn, reduces the test section mass accumulation rate and delays QF propagation at later stages. The enhancement of liquid carryover, and the early increase and subsequent decrease in quench velocity are all accentuated as the oscillation amplitude and frequency increase. Large amplitude oscillations change the characteristics of QF propagation and the heat transfer immediately downstream of QF substantially. Correlations based on constant-injection reflooding data are not adequate, even if they are applied on an average local-conditions basis

  8. U-Pb zircon age for a volcanic suite in the Rankin Inlet Group, Rankin Inlet map area, District of Keewatin, Northwest Territories

    Tella, S; Roddick, J C; VanBreemen, O [Geological Survey of Canada, Ottawa, ON (Canada)

    1997-12-31

    U-Pb zircon analyses from a felsic band within dominantly mafic volcanics of the Rankin Inlet Group yields a U-Pb upper concordia intercept age of 2663 {+-} 3 Ma. These supracrustals at Rankin Inlet appear to be 15-20 Ma younger than volcanics of the Kaminak Group in the Tavani area, 70 km to the southwest. The 2.68-2.66 Ga volcanism in the Tavani and Rankin Inlet areas coincided with the last stage of the main phase of magmatism in the Slave Structural Province. (author). 16 refs., 1 tab., 3 figs.

  9. U-Pb zircon age for a volcanic suite in the Rankin Inlet Group, Rankin Inlet map area, District of Keewatin, Northwest Territories

    Tella, S.; Roddick, J.C.; VanBreemen, O.

    1996-01-01

    U-Pb zircon analyses from a felsic band within dominantly mafic volcanics of the Rankin Inlet Group yields a U-Pb upper concordia intercept age of 2663 ± 3 Ma. These supracrustals at Rankin Inlet appear to be 15-20 Ma younger than volcanics of the Kaminak Group in the Tavani area, 70 km to the southwest. The 2.68-2.66 Ga volcanism in the Tavani and Rankin Inlet areas coincided with the last stage of the main phase of magmatism in the Slave Structural Province. (author). 16 refs., 1 tab., 3 figs

  10. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase I

    National Aeronautics and Space Administration — Enabling a new generation of high speed civil aircraft will require breakthrough developments in propulsion design, including novel techniques to optimize inlet...

  11. Tidal and subtidal exchange flows at an inlet of the Wadden Sea

    Valle-Levinson, Arnoldo; Stanev, Emil; Badewien, Thomas H.

    2018-03-01

    Observations of underway velocity profiles during complete spring and neap tidal cycles were used to determine whether the spatial structures of tidal and subtidal flows at a tidal inlet in a multiple-inlet embayment are consistent with those observed at single-inlet embayments. Measurements were obtained at the Otzumer Balje, one of the multiple inlets among the East Frisian Islands of the Wadden Sea. The 1.5 km-wide inlet displayed a bathymetric profile consisting of a channel ∼15 m deep flanked by tide observations spanned 36 h in the period May 11-12, 2011, while spring tide measurements exceeded 48 h from May 17 to May 19, 2011. Analysis of observations indicate that frictional effects from bathymetry molded tidal flows. Spatial distributions of semidiurnal tidal current amplitude and phase conform to those predicted by an analytical model for a basin with one inlet. Maximum semidiurnal flows appear at the surface in the channel, furthest away from bottom friction effects. Therefore, Otzumer Balje displays tidal hydrodynamics that are independent of the other inlets of the embayment. Subtidal exchange flows are laterally sheared, with residual inflow in the channel combined with outflow over shoals. The spatial distribution of these residual flows follow theoretical expectations of tidally driven flows interacting with bathymetry. Such distribution is similar to the tidal residual circulation at other inlets with only one communication to the ocean, suggesting that at subtidal scales the Otzumer Balje responds to tidal forcing independently of the other inlets.

  12. Performance and Adaptive Surge-Preventing Acceleration Prediction of a Turboshaft Engine under Inlet Flow Distortion

    Cao Dalu

    2017-01-01

    Full Text Available The intention of this paper is to research the inlet flow distortion influence on overall performance of turboshaft engine and put forward a method called Distortion Factor Item (DFI to improve the fuel supply plan for surge-preventing acceleration when turboshaft engine suddenly encounters inlet flow distortion. Based on the parallel compressor theory, steady-state and transition-state numerical simulation model of turboshaft engine with sub-compressor model were established for researching the influence of inlet flow distortion on turboshaft engine. This paper made a detailed analysis on the compressor operation from the aspects of performance and stability, and then analyzed the overall performance and dynamic response of the whole engine under inlet flow distortion. Improved fuel supply plan with DFI method was applied to control the acceleration process adaptively when encountering different inlet flow distortion. Several simulation examples about extreme natural environments were calculated to testify DFI method’s environmental applicability. The result shows that the inlet flow distortion reduces the air inflow and decreases the surge margin of compressor, and increase the engine exhaust loss. Encountering inlet flow distortion has many adverse influences such as sudden rotor acceleration, turbine inlet temperature rise and power output reduction. By using improved fuel supply plan with DFI, turboshaft engine above-idle acceleration can avoid surge effectively under inlet flow distortion with environmental applicability.

  13. High Pressure Atmospheric Sampling Inlet System for Venus or the Gas Giants, Phase I

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized high pressure atmospheric sampling inlet system for sample acquisition in extreme planetary environments,...

  14. Reconstruction of core inlet temperature distribution by cold leg temperature measurements

    Saarinen, S.; Antila, M.

    2010-01-01

    The reduced core of Loviisa NPP contains 33 thermocouple measurements measuring the core inlet temperature. Currently, these thermocouple measurements are not used in determining the inlet temperature distribution. The average of cold leg temperature measurements is used as inlet temperature for each fuel assembly. In practice, the inlet temperature distribution is not constant. Thus, using a constant inlet temperature distribution induces asymmetries in the measured core power distribution. Using a more realistic inlet temperature distribution would help us to reduce virtual asymmetries of the core power distribution and increase the thermal margins of the core. The thermocouples at the inlet cannot be used directly to measure the inlet temperature accurately because the calibration of the thermocouples that is done at hot zero power conditions is no longer valid at full power, when there is temperature change across the core region. This is due to the effect of neutron irradiation on the Seebeck coefficient of the thermocouple wires. Therefore, we investigate in this paper a method to determine the inlet temperature distribution based on the cold leg temperature measurements. With this method we rely on the assumption that although the core inlet thermocouple measurements do not measure the absolute temperature accurately they do measure temperature changes with sufficient accuracy particularly in big disturbances. During the yearly testing of steam generator safety valves we observe a large temperature increase up to 12 degrees in the cold leg temperature. The change in the temperature of one of the cold legs causes a local disturbance in the core inlet temperature distribution. Using the temperature changes observed in the inlet thermocouple measurements we are able to fit six core inlet temperature response functions, one for each cold leg. The value of a function at an assembly inlet is determined only by the corresponding cold leg temperature disturbance

  15. The Effect of the Holes Size Change of Lower-Support-Structure-Bottom Plate on the Reactor Core-Inlet Flow-Distribution

    Lee, Gong Hee; Bang, Young Seok; Cheong, Ae Ju

    2015-01-01

    Complex thermal-hydraulic phenomena exist inside PWR because reactor interiors include a fuel assembly, control rod assembly, ICI (In-Core Instrumentation), and other internal structures. Because changes to reactor design may influence interior, thermal-hydraulic characteristics, licensing applicants commonly conduct a flow-distribution test and use test results (e.g., core-inlet flow-rate distribution) as the input data for a core thermal-margin analysis program. Because the APR+ (Advanced Power Reactor Plus) had more fuel assemblies (241EA → 257EA) and the design of some internal structures was changed (from those of APR1400), the core-inlet flow-rate distribution for a 1/5 scaled-down reactor model was measured and high flow-rates were found especially near the outer region of the reactor core. In this study, to examine the effect of the holes size change (i.e. smaller diameter) in the outer region of the LSSBP, not a 50% blockage of the flow holes, on the reactor core-inlet flow-distribution, simulations were conducted with the commercial CFD (Computational Fluid Dynamics) software, ANSYS CFX R.14. The predicted results were compared with those of the original LSSBP. In this study, to examine the effect of the holes size change (smaller diameter) in the outer region of the LSSBP on the reactor core-inlet flow-distribution, simulations were conducted with the commercial CFD software, ANSYS CFX R.14. The predicted results were compared with those of the original LSSBP. Through these comparisons it was concluded that a more uniform distribution of the mass-flow rate at the core-inlet plane could be obtained by reducing the holes size in the outer region of the LSSBP

  16. Fixed points of quantum operations

    Arias, A.; Gheondea, A.; Gudder, S.

    2002-01-01

    Quantum operations frequently occur in quantum measurement theory, quantum probability, quantum computation, and quantum information theory. If an operator A is invariant under a quantum operation φ, we call A a φ-fixed point. Physically, the φ-fixed points are the operators that are not disturbed by the action of φ. Our main purpose is to answer the following question. If A is a φ-fixed point, is A compatible with the operation elements of φ? We shall show in general that the answer is no and we shall give some sufficient conditions under which the answer is yes. Our results will follow from some general theorems concerning completely positive maps and injectivity of operator systems and von Neumann algebras

  17. Observations of Seafloor Roughness in a Tidally Modulated Inlet

    Lippmann, T. C.; Hunt, J.

    2014-12-01

    The vertical structure of shallow water flows are influenced by the presence of a bottom boundary layer, which spans the water column for long period waves or mean flows. The nature of the boundary is determined in part by the roughness elements that make up the seafloor, and includes sometimes complex undulations associated with regular and irregular shaped bedforms whose scales range several orders of magnitude from orbital wave ripples (10-1 m) to mega-ripples (100 m) and even larger features (101-103) such as sand waves, bars, and dunes. Modeling efforts often parameterize the effects of roughness elements on flow fields, depending on the complexity of the boundary layer formulations. The problem is exacerbated by the transient nature of bedforms and their large spatial extent and variability. This is particularly important in high flow areas with large sediment transport, such as tidally dominated sandy inlets like New River Inlet, NC. Quantification of small scale seafloor variability over large spatial areas requires the use of mobile platforms that can measure with fine scale (order cm) accuracy in wide swaths. The problem is difficult in shallow water where waves and currents are large, and water clarity is often limited. In this work, we present results from bathymetric surveys obtained with the Coastal Bathymetry Survey System, a personal watercraft equipped with a Imagenex multibeam acoustic echosounder and Applanix POS-MV 320 GPS-aided inertial measurement unit. This system is able to measure shallow water seafloor bathymetry and backscatter intensity with very fine scale (10-1 m) resolution and over relatively large scales (103 m) in the presence of high waves and currents. Wavenumber spectra show that the noise floor of the resolved multibeam bathymetry is on the order of 2.5 - 5 cm in amplitude, depending on water depths ranging 2 - 6 m, and about 30 cm in wavelength. Seafloor roughness elements are estimated from wavenumber spectra across the inlet

  18. Fixed-point signal processing

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  19. Utilization Bound of Non-preemptive Fixed Priority Schedulers

    Park, Moonju; Chae, Jinseok

    It is known that the schedulability of a non-preemptive task set with fixed priority can be determined in pseudo-polynomial time. However, since Rate Monotonic scheduling is not optimal for non-preemptive scheduling, the applicability of existing polynomial time tests that provide sufficient schedulability conditions, such as Liu and Layland's bound, is limited. This letter proposes a new sufficient condition for non-preemptive fixed priority scheduling that can be used for any fixed priority assignment scheme. It is also shown that the proposed schedulability test has a tighter utilization bound than existing test methods.

  20. Mass independent kinetic energy reducing inlet system for vacuum environment

    Reilly, Peter T. A. [Knoxville, TN

    2010-12-14

    A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.

  1. Admiralty Inlet Pilot Tidal Project Final Technical Report

    Collar, Craig [Public Utility District No. 1 of Snohomish County, Everett, WA (United States)

    2015-09-14

    This document represents the final report for the Admiralty Inlet Pilot Tidal Project, located in Puget Sound, Washington, United States. The Project purpose was to license, permit, and install a grid-connected deep-water tidal turbine array (two turbines) to be used as a platform to gather operational and environmental data on tidal energy generation. The data could then be used to better inform the viability of commercial tidal energy generation from technical, economic, social, and environmental standpoints. This data would serve as a critical step towards the responsible advancement of commercial scale tidal energy in the United States and around the world. In late 2014, Project activities were discontinued due to escalating costs, and the DOE award was terminated in early 2015. Permitting, licensing, and engineering design activities were completed under this award. Final design, deployment, operation, and monitoring were not completed. This report discusses the results and accomplishments achieved under the subject award.

  2. Moderator inlet line hanger replacement for Pickering nuclear power station

    Kirkpatrick, R.A.; Bowman, J.M.; Symmons, W.R.; El-Nesr, S.

    1988-01-01

    Ontario Hydro's Pickering Nuclear Generating Station (PNGS), Units 1 and 2 were shutdown for large scale fuel channel replacement. Other nonroutine inspection and maintenance activities were performed to determine the overall condition of the units and it was seen that a moderator inlet line hanger (identified as HR-29) had failed in both units. Subsequent inspections during planned maintenance outages of Pickering NGS Units 3 and 4 revealed that hanger HR-29 had failed and required replacement. A research program was conducted to find a suitable technique. These problems included accessing tooling through small inspection ports, manipulating tooling from a significant distance and the high radiation fields within the vault. This paper describes the program undertaken to replace hanger HR-29. (author)

  3. Mitigation of thermal transients by tube bundle inlet plenum design

    Oras, J.J.; Kasza, K.E.

    1984-06-01

    A multiphase program aimed at investigating the importance of thermal buoyancy to LMFBR steam-generator and heat-exchanger thermal hydraulics under low-flow transient conditions is being conducted in the Argonne Mixing Components Test Facility (MCTF) on a 60 0 sector shell-side flow model of the Westinghouse straight-tube steam generator being developed under the US/DOE large-component development program. A series of shell-side constant-flow thermal-downramp transient tests have been conducted focusing on the phenomenon of thermal-buoyancy-induced-flow channeling. In addition, it was discovered that a shell-inlet flow-distribution plenum can play a significant role in mitigating the severity of a thermal transient entering a steam generator or heat exchanger

  4. Inlet throttling effect on the boiling two-phase flow stability in a natural circulation loop with a chimney

    Furuya, M.; Inada, F.; Yasuo, A.

    2001-01-01

    Experiments have been conducted to investigate an effect of inlet restriction on the thermal-hydraulic stability. A Test facility used in this study was designed and constructed to have non-dimensional values that are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation at the stability boundary was described as a function of heat flux and inlet subcooling independent of inlet restriction. In order to extend experimental database regarding thermal-hydraulic stability to different inlet restriction, numerical analysis was carried out based on the homogeneous flow model. Stability maps in reference to the core inlet subcooling and heat flux were presented for various inlet restrictions using the above-mentioned function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux. (orig.)

  5. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  6. North Inlet • Winyah Bay (NIW) National Estuarine Research Reserve Meteorological Data, North Inlet Estuary, Georgetown, South Carolina: 1997 • 1999.

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve System...

  7. Long-Term Ecological Research (LTER) Climate Data with Water Parameters from North Inlet Meteorological Station, North Inlet Estuary, Georgetown, South Carolina: 1982-1996.

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — Meteorological data with water parameters were collected on an hourly basis from June 3, 1982 through April 29, 1996 in the North Inlet Estuary, Georgetown County,...

  8. Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: a small inlet can contribute towards particulate organic matter production.

    Asaoka, Satoshi; Yamamoto, Tamiji

    2011-01-01

    Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

  10. Thermodynamic assessment of impact of inlet air cooling techniques on gas turbine and combined cycle performance

    Mohapatra, Alok Ku; Sanjay

    2014-01-01

    The article is focused on the comparison of impact of two different methods of inlet air cooling (vapor compression and vapor absorption cooling) integrated to a cooled gas turbine based combined cycle plant. Air-film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor pressure ratio, compressor inlet temperature (T i , C ), turbine inlet temperature (T i , T ), ambient relative humidity and ambient temperature on performance parameters of plant has been carried out. Optimum T i , T corresponding to maximum plant efficiency of combined cycle increases by 100 °C due to the integration of inlet air cooling. It has been observed that vapor compression cooling improves the efficiency of gas turbine cycle by 4.88% and work output by 14.77%. In case of vapor absorption cooling an improvement of 17.2% in gas cycle work output and 9.47% in gas cycle efficiency has been observed. For combined cycle configuration, however, vapor compression cooling should be preferred over absorption cooling in terms of higher plant performance. The optimum value of compressor inlet temperature has been observed to be 20 °C for the chosen set of conditions for both the inlet air cooling schemes. - Highlights: • Inlet air cooling improves performance of cooled gas turbine based combined cycle. • Vapor compression inlet air cooling is superior to vapor absorption inlet cooling. • For every turbine inlet temperature, there exists an optimum pressure ratio. • The optimum compressor inlet temperature is found to be 293 K

  11. Fixed kernel regression for voltammogram feature extraction

    Acevedo Rodriguez, F J; López-Sastre, R J; Gil-Jiménez, P; Maldonado Bascón, S; Ruiz-Reyes, N

    2009-01-01

    Cyclic voltammetry is an electroanalytical technique for obtaining information about substances under analysis without the need for complex flow systems. However, classifying the information in voltammograms obtained using this technique is difficult. In this paper, we propose the use of fixed kernel regression as a method for extracting features from these voltammograms, reducing the information to a few coefficients. The proposed approach has been applied to a wine classification problem with accuracy rates of over 98%. Although the method is described here for extracting voltammogram information, it can be used for other types of signals

  12. Flat Coalgebraic Fixed Point Logics

    Schröder, Lutz; Venema, Yde

    Fixed point logics are widely used in computer science, in particular in artificial intelligence and concurrency. The most expressive logics of this type are the μ-calculus and its relatives. However, popular fixed point logics tend to trade expressivity for simplicity and readability, and in fact often live within the single variable fragment of the μ-calculus. The family of such flat fixed point logics includes, e.g., CTL, the *-nesting-free fragment of PDL, and the logic of common knowledge. Here, we extend this notion to the generic semantic framework of coalgebraic logic, thus covering a wide range of logics beyond the standard μ-calculus including, e.g., flat fragments of the graded μ-calculus and the alternating-time μ-calculus (such as ATL), as well as probabilistic and monotone fixed point logics. Our main results are completeness of the Kozen-Park axiomatization and a timed-out tableaux method that matches ExpTime upper bounds inherited from the coalgebraic μ-calculus but avoids using automata.

  13. Enumerating matroids of fixed rank

    Pendavingh, R.; van der Pol, J.

    2017-01-01

    It has been conjectured that asymptotically almost all matroids are sparse paving, i.e. that~s(n)∼m(n)s(n)∼m(n), where m(n)m(n) denotes the number of matroids on a fixed groundset of size nn, and s(n)s(n) the number of sparse paving matroids. In an earlier paper, we showed that

  14. Adhesives for fixed orthodontic bands.

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

    2016-10-25

    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  15. CFD simulation and experimental validation of a GM type double inlet pulse tube refrigerator

    Banjare, Y. P.; Sahoo, R. K.; Sarangi, S. K.

    2010-04-01

    Pulse tube refrigerator has the advantages of long life and low vibration over the conventional cryocoolers, such as GM and stirling coolers because of the absence of moving parts in low temperature. This paper performs a three-dimensional computational fluid dynamic (CFD) simulation of a GM type double inlet pulse tube refrigerator (DIPTR) vertically aligned, operating under a variety of thermal boundary conditions. A commercial computational fluid dynamics (CFD) software package, Fluent 6.1 is used to model the oscillating flow inside a pulse tube refrigerator. The simulation represents fully coupled systems operating in steady-periodic mode. The externally imposed boundary conditions are sinusoidal pressure inlet by user defined function at one end of the tube and constant temperature or heat flux boundaries at the external walls of the cold-end heat exchangers. The experimental method to evaluate the optimum parameters of DIPTR is difficult. On the other hand, developing a computer code for CFD analysis is equally complex. The objectives of the present investigations are to ascertain the suitability of CFD based commercial package, Fluent for study of energy and fluid flow in DIPTR and to validate the CFD simulation results with available experimental data. The general results, such as the cool down behaviours of the system, phase relation between mass flow rate and pressure at cold end, the temperature profile along the wall of the cooler and refrigeration load are presented for different boundary conditions of the system. The results confirm that CFD based Fluent simulations are capable of elucidating complex periodic processes in DIPTR. The results also show that there is an excellent agreement between CFD simulation results and experimental results.

  16. Beluga coal field development: social effects and management alternatives. [West side of Cook Inlet

    Olsen, M.; Cluett, C.; Trimble, J.; Brody, S.; Howell, C.; Leman, L.; Svendsen, G.

    1979-05-01

    Plans are under way to mine the Beluga coal fields on the west side of Cook Inlet. The coal will be strip-mined for export, or to supply local electric generating plants, or both. Over the next 20 years, this coal development activity is likely to generate social and economic impacts at the local, regional, and state levels. The purpose of this study is to assess the potential social and economic effects of coal development, including employment and population growth, regional impacts, and the facility and service needs of a new settlement in the Beluga area. Of special concern is identifying the role of various governmental agencies in the development process. Potential effects on the natural environment are not examined in detail since they are expected to be controlled to acceptable levels through existing Federal and state laws. This report examines three possible levels of coal-field development and the settlement requirements associated with each. The most probable regional impacts associated with this development will include effects on the regional labor force, the market for coal, and the generation and distribution of revenues. The main regional labor force impacts will be positive in nature. The rate of regional unemployment is likely to decline slightly for the duration of the project, with an increase in wage income available for reinvestment in the region and a reduction in the number of individuals receiving unemployment insurance payments. Coal development is not expected to induce any significant inmigration of workers from outside the region.The development of the Beluga coal resources and the production of electricity from coal would add to the Kenai Peninsula Borough's tax base. The assessed value of coal lands around Beluga would likely increase and, in addition, Cook Inlet Region, Inc. would be the recipient of royalties from coal leases. A number of recommendations for research and governmental activities are presented.

  17. Blade bowing effects on radial equilibrium of inlet flow in axial compressor cascades

    Han XU

    2017-10-01

    Full Text Available The circumferentially averaged equation of the inlet flow radial equilibrium in axial compressor was deduced. It indicates that the blade inlet radial pressure gradient is closely related to the radial component of the circumferential fluctuation (CF source item. Several simplified cascades with/without aerodynamic loading were numerically studied to investigate the effects of blade bowing on the inlet flow radial equilibrium. A data reduction program was conducted to obtain the CF source from three-dimensional (3D simulation results. Flow parameters at the passage inlet were focused on and each term in the radial equilibrium equation was discussed quantitatively. Results indicate that the inviscid blade force is the inducement of the inlet CF due to geometrical asymmetry. Blade bowing induces variation of the inlet CF, thus changes the radial pressure gradient and leads to flow migration before leading edge (LE in the cascades. Positive bowing drives the inlet flow to migrate from end walls to mid-span and negative bowing turns it to the reverse direction to build a new equilibrium. In addition, comparative studies indicate that the inlet Mach number and blade loading can efficiently impact the effectiveness of blade bowing on radial equilibrium in compressor design.

  18. 33 CFR 110.170 - Lockwoods Folly Inlet, N.C.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lockwoods Folly Inlet, N.C. 110.170 Section 110.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.170 Lockwoods Folly Inlet, N.C. (a) Explosives...

  19. Evaluation of PM-10 commercial inlets for new surveillance air sampler

    Langer, G.

    1987-01-01

    The purpose of this project is to adapt an existing sampling inlet or develop a new one to collect airborne dust particles <10-μm aerodynamic equivalent diameter. These inlets are necessary to meet new EPA and DOE guidelines for surveillance of nuclear facilities

  20. Biochar-amended filter socks reduce herbicide losses via tile line surface inlets

    Standing water in depressions and behind terraces in fields with subsurface drainage systems can result in reduced crop yields. This concern can be partially alleviated by installing surface inlets that reduce the duration of ponding. Unfortunately, these inlets provide an open conduit for surface w...

  1. Vortex Generators in a Two-Dimensional, External-Compression Supersonic Inlet

    Baydar, Ezgihan; Lu, Frank K.; Slater, John W.

    2016-01-01

    Computational fluid dynamics simulations are performed as part of a process to design a vortex generator array for a two-dimensional inlet for Mach 1.6. The objective is to improve total pressure recovery a on at the engine face of the inlet. Both vane-type and ramp-type vortex generators are examined.

  2. The NASA Ames Hypersonic Combustor-Model Inlet CFD Simulations and Experimental Comparisons

    Venkatapathy, E.; Tokarcik-Polsky, S.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)

    1995-01-01

    Computations have been performed on a three-dimensional inlet associated with the NASA Ames combustor model for the hypersonic propulsion experiment in the 16-inch shock tunnel. The 3-dimensional inlet was designed to have the combustor inlet flow nearly two-dimensional and of sufficient mass flow necessary for combustion. The 16-inch shock tunnel experiment is a short duration test with test time of the order of milliseconds. The flow through the inlet is in chemical non-equilibrium. Two test entries have been completed and limited experimental results for the inlet region of the combustor-model are available. A number of CFD simulations, with various levels of simplifications such as 2-D simulations, 3-D simulations with and without chemical reactions, simulations with and without turbulent conditions, etc., have been performed. These simulations have helped determine the model inlet flow characteristics and the important factors that affect the combustor inlet flow and the sensitivity of the flow field to these simplifications. In the proposed paper, CFD modeling of the hypersonic inlet, results from the simulations and comparison with available experimental results will be presented.

  3. 77 FR 6065 - Proposed Information Collection; Comment Request; Cook Inlet Beluga Whale Economic Survey

    2012-02-07

    ... Collection; Comment Request; Cook Inlet Beluga Whale Economic Survey AGENCY: National Oceanic and Atmospheric... beluga whales found in the Cook Inlet of Alaska is one of five distinct population segments in United... beluga whale, such as population increases, are primarily the result of the non- consumptive value people...

  4. Efficient energy recovering air inlet system for an internal combustion engine

    2011-01-01

    An air inlet system (10) for an internal combustion engine (200) is provided. The air inlet system comprises an air intake port (20), an air output port (30) for providing air for a combustion chamber (202) of the combustion engine (200), and a turbine (40). The turbine (40) is situated in between

  5. Efficient energy recovering air inlet system for an international combustion engine

    2013-01-01

    An air inlet system (10) for an internal combustion engine (200) is provided. The air inlet system comprises an air intake port (20), an air output port (30) for providing air for a combustion chamber (202) of the combustion engine (200), and a turbine (40). The turbine (40) is situated in between

  6. 30 CFR 77.303 - Hot gas inlet chamber dropout doors.

    2010-07-01

    ... Section 77.303 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND... employ a hot gas inlet chamber shall be equipped with drop-out doors at the bottom of the inlet chamber...

  7. Full Scale Measurements and CFD Simulations of Diffuse Ceiling Inlet for Ventilation and Cooling of Densely Occupied Rooms

    Mikeska, Tomás; Fan, Jianhua

    2015-01-01

    Spaces with high occupant densities result in high heat gains and need for relatively high air change rate.By means of traditional mechanical ventilation diffusers it becomes a challenge to supply large amountsof fresh air into the space without creating a local discomfort for occupants. One...... comfort numerically. Results of our investigations have shown that diffuse ceiling inlet is a suitable solution for the spaceswith high density occupancy. The results have shown that transient calculations using Large Eddy Simulation models can predict well temperatures and velocity magnitude of air flow...

  8. Design of a reactor inlet temperature controller for EBR-2 using state feedback

    Vilim, R.B.; Planchon, H.P.

    1990-01-01

    A new reactor inlet temperature controller for pool type liquid-metal reactors has been developed and will be tested in EBR-II. The controller makes use of modern control techniques to take into account stratification and mixing in the cold pool during normal operation. Secondary flowrate is varied so that the reactor inlet temperature tracks a setpoint while reactor outlet temperature, primary flowrate and secondary cold leg temperature are treated as exogenous disturbances and are free to vary. A disturbance rejection technique minimizes the effect of these disturbances on inlet temperature. A linear quadratic regulator improves inlet temperature response. Tests in EBR-II will provide experimental data for assessing the performance improvements that modern control can produce over the existing EBR-II analog inlet temperature controller. 10 refs., 8 figs

  9. Selective catalytic reduction converter design: The effect of ammonia nonuniformity at inlet

    Paramadayalan, Thiyagarajan; Pant, Atul

    2013-01-01

    A three-dimensional CFD model of SCR converter with detailed chemistry is developed. The model is used to study the effects of radial variation in inlet ammonia profile on SCR emission performance at different temperatures. The model shows that radial variation in inlet ammonia concentration affects the SCR performance in the operating range of 200-400 .deg. C. In automotive SCR systems, ammonia is non-uniformly distributed due to evaporation/reaction of injected urea, and using a 1D model or a 3D model with flat ammonia profile at inlet for these conditions can result in erroneous emission prediction. The 3D SCR model is also used to study the effect of converter design parameters like inlet cone angle and monolith cell density on the SCR performance for a non-uniform ammonia concentration profile at the inlet. The performance of SCR is evaluated using DeNO x efficiency and ammonia slip

  10. N2-fixing red alder indirectly accelerates ecosystem nitrogen cycling

    Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

    2012-01-01

    Symbiotic N2-fixing tree species can accelerate ecosystem N dynamics through decomposition via direct pathways by producing readily decomposed leaf litter and increasing N supply to decomposers, as well as via indirect pathways by increasing tissue and detrital N in non-fixing vegetation. To evaluate the relative importance of these pathways, we compared three-year decomposition and N dynamics of N2-fixing red alder leaf litter (2.34 %N) to both low-N (0.68 %N) and high-N (1.21 %N) litter of non-fixing Douglas-fir, and decomposed each litter source in four forests dominated by either red alder or Douglas-fir. We also used experimental N fertilization of decomposition plots to assess elevated N availability as a potential mechanism of N2-fixer effects on litter mass loss and N dynamics. Direct effects of N2-fixing red alder on decomposition occurred primarily as faster N release from red alder than Douglas-fir litter, but direct increases in N supply to decomposers via fertilization did not stimulate decomposition of any litter. Fixed N indirectly influenced detrital dynamics by increasing Douglas-fir tissue and litter N concentrations, which accelerated litter N release without accelerating mass loss. By increasing soil N, tissue N, and the rate of N release from litter of non-fixers, we conclude that N2-fixing vegetation can indirectly foster plant-soil feedbacks that contribute to the persistence of elevated N availability in terrestrial ecosystems.

  11. 78 FR 29063 - Survey of Urban Rates for Fixed Voice and Fixed Broadband Residential Services

    2013-05-17

    ... the USF/ICC Transformation Order. DATES: Effective May 17, 2013. This Order contains information... public inspection during regular business hours in the FCC Reference Center, Room CY-A257, 445 12th... released the USF/ICC Transformation Order and FNPRM, 76 FR 73830, November 29, 2011, which comprehensively...

  12. Numerical Simulation of Boundary Layer Ingesting (BLI) Inlet-Fan Interaction

    Giuliani, James; Chen, Jen-Ping; Beach, Timothy; Bakhle, Milind

    2014-01-01

    Future civil transport designs may incorporate engine inlets integrated into the body of the aircraft to take advantage of efficiency increases due to weight and drag reduction. Additional increases in engine efficiency are predicted if the inlet ingests the lower momentum boundary layer flow. Previous studies have shown, however, that efficiency benefits of Boundary Layer Ingesting (BLI) ingestion are very sensitive to the magnitude of fan and duct losses, and blade structural response to the non-uniform flow field that results from a BLI inlet has not been studied in-depth. This paper presents an effort to extend the modeling capabilities of an existing rotating turbomachinery unsteady analysis code to include the ability to solve the external and internal flow fields of a BLI inlet. The TURBO code has been a successful tool in evaluating fan response to flow distortions for traditional engine/inlet integrations, such as the development of rotating stall and inlet distortion through compressor stages. This paper describes the first phase of an effort to extend the TURBO model to calculate the external and inlet flowfield upstream of fan so that accurate pressure distortions that result from BLI configurations can be computed and used to analyze fan aerodynamics and structural response. To validate the TURBO program modifications for the BLI flowfield, experimental test data obtained by NASA for a flushmounted S-duct with large amounts of boundary layer ingestion was modeled. Results for the flow upstream and in the inlet are presented and compared to experimental data for several high Reynolds number flows to validate the modifications to the solver. Quantitative data is presented that indicates good predictive capability of the model in the upstream flow. A representative fan is attached to the inlet and results are presented for the coupled inlet/fan model. The impact on the total pressure distortion at the AIP after the fan is attached is examined.

  13. Numerical Studies on the Effects of the Channel-Inlet-Pressure Difference in the Pressure-Retarded Osmosis (PRO) Power System

    Hong, Sung Soo; Ryoo, Won; Chung, Gui Yung [Hong-Ik University, Seoul (Korea, Republic of); Chun, Myung-Suk [Korea Institute of Science and Technology (KIST), Seoul (Korea, Republic of)

    2014-02-15

    In the spiral wound module of the pressure-retarded osmosis (PRO) system for the salinity gradient power generation, effects of the inlet pressure differences between feed-channel and draw-channel were studied. Fluxes of water and solute through membrane and power were estimated. The water flux through membrane decreased along the x-direction and increased along the y-direction with the increase of inlet pressure differences between two channels. On the other hand, the solute flux through membrane showed the opposite trend. The concentration of flow in the feed-channel increased a lot along the y-direction and that in the draw-channel decreased along the x-direction. In our system, for the inlet pressure differences of 1-11 atm, the flow rate in the feed-channel decreased about 8-13% and that in the draw-channel increased by the same amount. The power density increased and then decreased with the increasing inlet pressure difference.

  14. Numerical Studies on the Effects of the Channel-Inlet-Pressure Difference in the Pressure-Retarded Osmosis (PRO) Power System

    Hong, Sung Soo; Ryoo, Won; Chung, Gui Yung; Chun, Myung-Suk

    2014-01-01

    In the spiral wound module of the pressure-retarded osmosis (PRO) system for the salinity gradient power generation, effects of the inlet pressure differences between feed-channel and draw-channel were studied. Fluxes of water and solute through membrane and power were estimated. The water flux through membrane decreased along the x-direction and increased along the y-direction with the increase of inlet pressure differences between two channels. On the other hand, the solute flux through membrane showed the opposite trend. The concentration of flow in the feed-channel increased a lot along the y-direction and that in the draw-channel decreased along the x-direction. In our system, for the inlet pressure differences of 1-11 atm, the flow rate in the feed-channel decreased about 8-13% and that in the draw-channel increased by the same amount. The power density increased and then decreased with the increasing inlet pressure difference

  15. Parametric Analysis of a Hypersonic Inlet using Computational Fluid Dynamics

    Oliden, Daniel

    For CFD validation, hypersonic flow fields are simulated and compared with experimental data specifically designed to recreate conditions found by hypersonic vehicles. Simulated flow fields on a cone-ogive with flare at Mach 7.2 are compared with experimental data from NASA Ames Research Center 3.5" hypersonic wind tunnel. A parametric study of turbulence models is presented and concludes that the k-kl-omega transition and SST transition turbulence model have the best correlation. Downstream of the flare's shockwave, good correlation is found for all boundary layer profiles, with some slight discrepancies of the static temperature near the surface. Simulated flow fields on a blunt cone with flare above Mach 10 are compared with experimental data from CUBRC LENS hypervelocity shock tunnel. Lack of vibrational non-equilibrium calculations causes discrepancies in heat flux near the leading edge. Temperature profiles, where non-equilibrium effects are dominant, are compared with the dissociation of molecules to show the effects of dissociation on static temperature. Following the validation studies is a parametric analysis of a hypersonic inlet from Mach 6 to 20. Compressor performance is investigated for numerous cowl leading edge locations up to speeds of Mach 10. The variable cowl study showed positive trends in compressor performance parameters for a range of Mach numbers that arise from maximizing the intake of compressed flow. An interesting phenomenon due to the change in shock wave formation for different Mach numbers developed inside the cowl that had a negative influence on the total pressure recovery. Investigation of the hypersonic inlet at different altitudes is performed to study the effects of Reynolds number, and consequently, turbulent viscous effects on compressor performance. Turbulent boundary layer separation was noted as the cause for a change in compressor performance parameters due to a change in Reynolds number. This effect would not be

  16. A fixed-point farrago

    Shapiro, Joel H

    2016-01-01

    This text provides an introduction to some of the best-known fixed-point theorems, with an emphasis on their interactions with topics in analysis. The level of exposition increases gradually throughout the book, building from a basic requirement of undergraduate proficiency to graduate-level sophistication. Appendices provide an introduction to (or refresher on) some of the prerequisite material and exercises are integrated into the text, contributing to the volume’s ability to be used as a self-contained text. Readers will find the presentation especially useful for independent study or as a supplement to a graduate course in fixed-point theory. The material is split into four parts: the first introduces the Banach Contraction-Mapping Principle and the Brouwer Fixed-Point Theorem, along with a selection of interesting applications; the second focuses on Brouwer’s theorem and its application to John Nash’s work; the third applies Brouwer’s theorem to spaces of infinite dimension; and the fourth rests ...

  17. Determinants of private fixed investment in emerging country

    Goitsemodimo Abel Molocwa

    2018-03-01

    Full Text Available The neoclassical and Keynesian theories regard private investment not only as a source of economic growth but also as a determinant of the potential extent of the national income. The aim of this research was to examine the determinants of private fixed investment in South Africa by employing the Johansen cointegration technique and the vector error correction model (VECM analysis. Based on the literature survey it appears that the previous studies mainly focused on private investment in manufacturing and infrastructure sectors therefore this is envisaged to add knowledge to a body of economics literature in this area by focusing more on private fixed investment and its determinants in South Africa. The study concludes that for the period under investigation GDP has the positive sign as expected. This suggests that in the long run it impact positively on private fixed investment. The findings of the study also confirmed that tax rate is a complementary to private fixed investment. Similarly, the real exchange rate coefficient was negative as expected which suggests that the depreciation of the currency stimulates the growth of South Africa private fixed investment. It is obvious that even the best economic model cannot achieve the expected outcomes immediately but these results encourage the study to believe that the South African monetary policy on exchange rate complements private fixed investment. Therefore, the study proposes that both even though both growth and general tax rate are difficult to accomplish simultaneously, they should be used to promote the flow of private fixed investment in South Africa.

  18. Smart actuation of inlet guide vanes for small turbine engine

    Rusovici, Razvan; Kwok Choon, Stephen T.; Sepri, Paavo; Feys, Joshuo

    2011-04-01

    Unmanned Aerial Vehicles (UAVs) have gained popularity over the past few years to become an indispensable part of aerial missions that include reconnaissance, surveillance, and communication [1]. As a result, advancements in small jet-engine performance are needed to increase the performance (range, payload and efficiency) of the UAV. These jet engines designed especially for UAV's are characterized by thrust force on the order of 100N and due to their size and weight limitations, may lack advanced flow control devices such as IGV [2]. The goal of the current study was to present a conceptual design of an IGV smart-material based actuation mechanism that would be simple, compact and lightweight. The compressor section of an engine increases the pressure and conditions the flow before the air enters the combustion chamber [3]. The airflow entering the compressor is often turbulent due to the high angle of incidence between engine inlet and free-stream velocity, or existing atmospheric turbulence. Actuated IGV are used to help control the relative angle of incidence of the flow that enters the engine compressor, thereby preventing flow separation, compressor stall and thus extending the compressor's operating envelope [4]. Turbine jet- engines which employ variable IGV were developed by Rolls Royce (Trent DR-900) and General Electric (J79).

  19. Water resources of the Cook Inlet Basin, Alaska

    Freethey, Geoffrey W.; Scully, David R.

    1980-01-01

    Ground-water and surface-water systems of Cook Inlet basin, Alaska, are analyzed. Geologic and topographic features that control the movement and regional availability of ground water are explained and illustrated. Five aquifer systems beneath the most populous areas are described. Estimates of ground-water yield were determined for the region by using ground-water data for the populated areas and by extrapolating known subsurface conditions and interpreting subsurface conditions from surficial features in the other areas. Area maps of generalized geology, Quaternary sediment thickness, and general availability of ground water are shown. Surface-water resources are summarized by describing how basin characteristics affect the discharge in streams. Seasonal trend of streamflow for three types of streams is described. Regression equations for 4 streamflow characteristics (annual, monthly minimum, and maximum discharge) were obtained by using gaging station streamflow characteristics and 10 basin characteristics. In the 24 regression equations presented, drainage area is the most significant basin characteristic, but 5 others are used. Maps of mean annual unit runoff and minimum unit yield for 7 consecutive days with a recurrence interval of 10 years are shown. Historic discharge data at gaging stations is tabulated and representative low-flow and flood-flow frequency curves are shown. (USGS)

  20. Membrane Inlet Mass Spectrometry for Homeland Security and Forensic Applications

    Giannoukos, Stamatios; Brkić, Boris; Taylor, Stephen; France, Neil

    2015-02-01

    A man-portable membrane inlet mass spectrometer has been built and tested to detect and monitor characteristic odors emitted from the human body and also from threat substances. In each case, a heated membrane sampling probe was used. During human scent monitoring experiments, data were obtained for inorganic gases and volatile organic compounds emitted from human breath and sweat in a confined space. Volatile emissions were detected from the human body at low ppb concentrations. Experiments with compounds associated with narcotics, explosives, and chemical warfare agents were conducted for a range of membrane types. Test compounds included methyl benzoate (odor signature of cocaine), piperidine (precursor in clandestine phencyclidine manufacturing processes), 2-nitrotoluene (breakdown product of TNT), cyclohexanone (volatile signature of plastic explosives), dimethyl methylphosphonate (used in sarin and soman nerve agent production), and 2-chloroethyl ethyl sulfide (simulant compound for sulfur mustard gas). Gas phase calibration experiments were performed allowing sub-ppb LOD to be established. The results showed excellent linearity versus concentration and rapid membrane response times.

  1. Southern Salish Sea Habitat Map Series: Admiralty Inlet

    Cochrane, Guy R.; Dethier, Megan N.; Hodson, Timothy O.; Kull, Kristine K.; Golden, Nadine E.; Ritchie, Andrew C.; Moegling, Crescent; Pacunski, Robert E.; Cochrane, Guy R.

    2015-01-01

    In 2010 the Environmental Protection Agency, Region 10 initiated the Puget Sound Scientific Studies and Technical Investigations Assistance Program, designed to support research in support of implementing the Puget Sound Action Agenda. The Action Agenda was created in response to Puget Sound having been designated as one of 28 estuaries of national significance under section 320 of the U.S. Clean Water Act, and its overall goal is to restore the Puget Sound Estuary's environment by 2020. The Southern Salish Sea Mapping Project was funded by the Assistance Program request for proposals process, which also supports a large number of coastal-zone- and ocean-management issues. The issues include the recommendations of the Marine Protected Areas Work Group to the Washington State Legislature (Van Cleve and others, 2009), which endorses a Puget Sound and coast-wide marine conservation needs assessment, gap analysis of existing Marine Protected Areas (MPA) and recommendations for action. This publication is the first of four U.S. Geological Survey Scientific Investigation Maps that make up the Southern Salish Sea Mapping Project. The remaining three map blocks to be published in the future, located south of Admiralty Inlet, are shown in figure 1.

  2. Fabric inlet stratifiers for solar tanks with different volume flow rates

    Andersen, Elsa; Furbo, Simon

    2006-01-01

    In this paper investigations of two different two layer fabric stratification pipes are presented and compared to a rigid stratification pipe with holes with “non-return” valves. The fabric stratification pipes are constructed of filament polyester and acrylic. The fabric pipes are mounted in the...

  3. Drying kinetics characteristic of Indonesia lignite coal (IBC) using lab scale fixed bed reactor

    Kang, TaeJin; Jeon, DoMan; Namkung, Hueon; Jang, DongHa; Jeon, Youngshin; Kim, Hyungtaek [Ajou Univ., Suwon (Korea, Republic of). Div. of Energy Systems Research

    2013-07-01

    Recent instability of energy market arouse a lot of interest about coal which has a tremendous amount of proven coal reserves worldwide. South Korea hold the second rank by importing 80 million tons of coal in 2007 following by Japan. Among various coals, there is disused coal. It's called Low Rank Coal (LRC). Drying process has to be preceded before being utilized as power plant. In this study, drying kinetics of LRC is induced by using a fixed bed reactor. The drying kinetics was deduced from particle size, the inlet gas temperature, the drying time, the gas velocity, and the L/D ratio. The consideration on Reynold's number was taken for correction of gas velocity, particle size, and the L/D ratio was taken for correction packing height of coal. It can be found that active drying of free water and phase boundary reaction is suitable mechanism through the fixed bed reactor experiments.

  4. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  5. Study on the design of inlet and exhaust system of a stationary internal combustion engine

    Kesgin, Ugur

    2005-01-01

    The design and operational variables of inlet and exhaust systems are decisive to determine overall engine performance. The best engine overall performance can be obtained by proper design of the engine inlet and exhaust systems and by matching the correct turbocharger to the engine. This paper presents the results of investigations to design the inlet and exhaust systems of a stationary natural gas engine family. To do this, a computational model is verified in which zero dimensional phenomena within the cylinder and one dimensional phenomena in the engine inlet and exhaust systems are used. Using this engine model, the effects of the parameters of the inlet and exhaust systems on the engine performance are obtained. In particular, the following parameters are chosen: valve timing, valve diameter, valve lift profiles, diameter of the exhaust manifold, inlet and exhaust pipe lengths, and geometry of pipe junctions. Proper sizing of the inlet and exhaust pipe systems is achieved very precisely by these investigations. Also, valve timing is tuned by using the results obtained in this study. In general, a very high improvement potential for the engines studied here is presented

  6. Classifier utility modeling and analysis of hypersonic inlet start/unstart considering training data costs

    Chang, Juntao; Hu, Qinghua; Yu, Daren; Bao, Wen

    2011-11-01

    Start/unstart detection is one of the most important issues of hypersonic inlets and is also the foundation of protection control of scramjet. The inlet start/unstart detection can be attributed to a standard pattern classification problem, and the training sample costs have to be considered for the classifier modeling as the CFD numerical simulations and wind tunnel experiments of hypersonic inlets both cost time and money. To solve this problem, the CFD simulation of inlet is studied at first step, and the simulation results could provide the training data for pattern classification of hypersonic inlet start/unstart. Then the classifier modeling technology and maximum classifier utility theories are introduced to analyze the effect of training data cost on classifier utility. In conclusion, it is useful to introduce support vector machine algorithms to acquire the classifier model of hypersonic inlet start/unstart, and the minimum total cost of hypersonic inlet start/unstart classifier can be obtained by the maximum classifier utility theories.

  7. Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

    Aspi R. Wadia

    2011-01-01

    Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

  8. 75 FR 1582 - Endangered and Threatened Species; Designation of Critical Habitat for the Cook Inlet Beluga Whale

    2010-01-12

    ... Cook Inlet Beluga Whale AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... designate critical habitat for the endangered Cook Inlet beluga whale, Delphinapterus leucas, under the... the Cook Inlet beluga whale can be found on our Web site at: http://www.fakr.noaa.gov/ FOR FURTHER...

  9. Background-Oriented Schlieren used in a hypersonic inlet test at NASA GRC

    Clem, Michelle; Woike, Mark; Saunders, John

    2016-01-01

    Background Oriented Schlieren (BOS) is a derivative of the classical schlieren technology, which is used to visualize density gradients, such as shock wave structures in a wind tunnel. Changes in refractive index resulting from density gradients cause light rays to bend, resulting in apparent motion of a random background pattern. The apparent motion of the pattern is determined using cross-correlation algorithms (between no-flow and with-flow image pairs) producing a schlieren-like image. One advantage of BOS is its simplified setup which enables a larger field-of-view (FOV) than traditional schlieren systems. In the present study, BOS was implemented into the Combined Cycle Engine Large-Scale Inlet Mode Transition Experiment (CCE LIMX) in the 10x10 Supersonic Wind Tunnel at NASA Glenn Research Center. The model hardware for the CCE LIMX accommodates a fully integrated turbine based combined cycle propulsion system. To date, inlet mode transition between turbine and ramjet operation has been successfully demonstrated. High-speed BOS was used to visualize the behavior of the flow structures shock waves during unsteady inlet unstarts, a phenomenon known as buzz. Transient video images of inlet buzz were recorded for both the ramjet flow path (high speed inlet) and turbine flow path (low speed inlet). To understand the stability limits of the inlet, operation was pushed to the point of unstart and buzz. BOS was implemented in order to view both inlets simultaneously, since the required FOV was beyond the capability of the current traditional schlieren system. An example of BOS data (Images 1-6) capturing inlet buzz are presented.

  10. Assessment of the Particulate Food Supply Available for Mussel ( Mytilus spp.) Farming in a Semi-enclosed, Northern Inlet

    Penney, R. W.; McKenzie, C. H.; Mills, T. J.

    2001-07-01

    Temporal variability in the quantity, organic content, and phytoplankton composition of the particulate food supply available to a cultured mussel population was assessed for a 3-year period in a small inlet of Notre Dame Bay, Newfoundland, Canada. The study site had a restricted flushing rate estimated at 1-2·75 times wk -1for a complete water exchange. The quantity of both total (TPM) and organic (POM) seston varied temporally from 0·7-23·7 mg l -1and 0·05-1·97 mg l -1respectively during the 3-year sampling period. TPM typically remained relatively high (>10 mg l -1) through the winter and spring period. Most of the seasonal variation in total seston was due to seasonal variability in the PIM component. Both PIM and POM concentrations were seasonally lowest during summer. The organic fraction of the seston (POM/TPM ratio) was seasonally low in winter and increased steadily through spring and summer to reach its maximum in the autumn. The living phytoplankton component of the seston was typically dominated, both numerically and in biomass, by a variety of diatom and autotrophic nanoflagellate species in the 2- 20-μm diameter size range. Discrete diatom population blooms occurred in the autumn of all three years and largely consisted of a single species, Skeletonema costatum. Phytoplankton:detritus ratios were significantly lower during winter. Total phytoplankton biomass levels were seasonally low during winter and summer and were associated with seasonal variation in diatom biomass. We conducted modelling simulations of relationships among seston organic food levels, their temporal variability, tidal flushing rates, cultured mussel biomass and production indices, and estimates of mussel maintenance ration requirements to predict the adequacy of northern inlets to sustain commercial-scale mussel farm development. We conclude from these simulations that small, semi-enclosed, northern inlets likely frequently experience periods when naturally occurring organic

  11. Adhesives for fixed orthodontic brackets.

    Mandall, N A; Millett, D T; Mattick, C R; Hickman, J; Macfarlane, T V; Worthington, H V

    2003-01-01

    Bonding of orthodontic brackets to teeth is important to enable effective and efficient treatment with fixed appliances. The problem is bracket failure during treatment which increases operator chairside time and lengthens treatment time. A prolonged treatment is likely to increase the oral health risks of orthodontic treatment with fixed appliances one of which is irreversible enamel decalcification. To evaluate the effectiveness of different orthodontic adhesives for bonding. Electronic databases: the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Date of most recent searches: August 2002 (CENTRAL) (The Cochrane Library Issue 2, 2002). Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing two different adhesive groups. Participants were patients with fixed orthodontic appliances. The interventions were adhesives that bonded stainless steel brackets to all teeth except the molars. The primary outcome was debond or bracket failure. Data were recorded on decalcification as a secondary outcome, if present. Information regarding methods, participants, interventions, outcome measures and results were extracted in duplicate by pairs of reviewers (Nicky Mandall (NM) and Rye Mattick (CRM); Declan Millett (DTM) and Joy Hickman (JH2)). Since the data were not presented in a form that was amenable to meta-analysis, the results of the review are presented in narrative form only. Three trials satisfied the inclusion criteria. A chemical cured composite was compared with a light cure composite (one trial), a conventional glass ionomer cement (one trial) and a polyacid-modified resin composite (compomer) (one trial). The quality of the trial reports was generally poor. It is difficult to draw any conclusions from this review, however, suggestions are made for methods of improving future research involving

  12. BRST gauge fixing and regularization

    Damgaard, P.H.; Jonghe, F. de; Sollacher, R.

    1995-05-01

    In the presence of consistent regulators, the standard procedure of BRST gauge fixing (or moving from one gauge to another) can require non-trivial modifications. These modifications occur at the quantum level, and gauges exist which are only well-defined when quantum mechanical modifications are correctly taken into account. We illustrate how this phenomenon manifests itself in the solvable case of two-dimensional bosonization in the path-integral formalism. As a by-product, we show how to derive smooth bosonization in Batalin-Vilkovisky Lagrangian BRST quantization. (orig.)

  13. GOLD and the fixed ratio

    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  14. Performance and economic enhancement of cogeneration gas turbines through compressor inlet air cooling

    Delucia, M.; Bronconi, R.; Carnevale, E.

    1994-04-01

    Gas turbine air cooling systems serve to raise performance to peak power levels during the hot months when high atmospheric temperatures cause reductions in net power output. This work describes the technical and economic advantages of providing a compressor inlet air cooling system to increase the gas turbine's power rating and reduce its heat rate. The pros and cons of state-of-the-art cooling technologies, i.e., absorption and compression refrigeration, with and without thermal energy storage, were examined in order to select the most suitable cooling solution. Heavy-duty gas turbine cogeneration systems with and without absorption units were modeled, as well as various industrial sectors, i.e., paper and pulp, pharmaceuticals, food processing, textiles, tanning, and building materials. The ambient temperature variations were modeled so the effects of climate could be accounted for in the simulation. The results validated the advantages of gas turbine cogeneration with absorption air cooling as compared to other systems without air cooling.

  15. Ecology and demographics of Pacific sand lance, Ammodytes hexapterus Pallas, in Lower Cook Inlet, Alaska

    Robards, Martin D.; Piatt, John F.

    2000-01-01

    Distinct sand lance populations occur within the relatively small geographic area of Lower Cook Inlet, Alaska. Marked meso-scale differences in abundance, growth, and mortality exist as a consequence of differing oceanographic regimes. Growth rate within populations (between years) was positively correlated with temperature. However, this did not extend to inter-population comparisons where differing growth rates were better correlated to marine productivity. Most sand lance reached maturity in their second year. Field observations and indices of maturity, gonad development, and ova-size distribution all indicated that sand lance spawn once each year. Sand lance spawned intertidally in late September and October on fine gravel/sandy beaches. Embryos developed over 67 days through periods of intertidal exposure and sub-freezing air temperatures. Mean dry-weight energy value of sand lance cycles seasonally, peaking in spring and early summer (20.91 kJg-1 for males, 21.08 kJg-1 for females), and subsequently declining by about 25% during late summer and fall (15.91 kJg-1 for males, 15.74 kJg-1 for females). Sand lance enter the winter with close to their minimum whole body energy content. Dry weight energy densities of juveniles increased from a minimum 16.67 kJg-1 to a maximum of 19.68 kJg-1 and are higher than adults in late summer.

  16. Fuel effects on the stability of turbulent flames with compositionally inhomogeneous inlets

    Guiberti, T. F.

    2016-10-11

    This paper reports an analysis of the influence of fuels on the stabilization of turbulent piloted jet flames with inhomogeneous inlets. The burner is identical to that used earlier by the Sydney Group and employs two concentric tubes within the pilot stream. The inner tube, carrying fuel, can be recessed, leading to a varying degree of inhomogeneity in mixing with the outer air stream. Three fuels are tested: dimethyl ether (DME), liquefied petroleum gas (LPG), and compressed natural gas (CNG). It is found that improvement in flame stability at the optimal compositional inhomogeneity is highest for CNG and lowest for DME. Three possible reasons for this different enhancement in stability are investigated: mixing patterns, pilot effects, and fuel chemistry. Numerical simulations realized in the injection tube highlight similarities and differences in the mixing patterns for all three fuels and demonstrate that mixing cannot explain the different stability gains. Changing the heat release rates from the pilot affects the three fuels in similar ways and this also implies that the pilot stream is unlikely to be responsible for the observed differences. Fuel reactivity is identified as a key factor in enhancing stability at some optimal compositional inhomogeneity. This is confirmed by inference from joint images of PLIF-OH and PLIF-CHO, collected at a repetition rate of 10kHz in turbulent flames of DME, and from one-dimensional calculations of laminar flames using detailed chemistry for DME, CNG, and LPG.

  17. Inlet effects on vertical-downward air–water two-phase flow

    Qiao, Shouxu; Mena, Daniel; Kim, Seungjin, E-mail: skim@psu.edu

    2017-02-15

    Highlights: • Inlet effects on two-phase flow parameters in vertical-downward flow are studied. • Flow regimes in the vertical-downward two-phase flow are defined. • Vertical-downward flow regime maps for three inlet configurations are developed. • Frictional pressure loss analysis for three different inlets is performed. • Database of local two-phase flow parameters for each inlet configuration. - Abstract: This paper focuses on investigating the geometric effects of inlets on global and local two-phase flow parameters in vertical-downward air–water two-phase flow. Flow visualization, frictional pressure loss analysis, and local experiments are performed in a test facility constructed from 50.8 mm inner diameter acrylic pipes. Three types of inlets of interest are studied: (1) two-phase flow injector without a flow straightener (Type A), (2) two-phase flow injector with a flow straightener (Type B), and (3) injection through a horizontal-to-vertical-downward 90° vertical elbow (Type C). A detailed flow visualization study is performed to characterize flow regimes including bubbly, slug, churn-turbulent, and annular flow. Flow regime maps for each inlet are developed and compared to identify the effects of each inlet. Frictional pressure loss analysis shows that the Lockhart–Martinelli method is capable of correlating the frictional loss data acquired for Type B and Type C inlets with a coefficient value of C = 25, but additional data may be needed to model the Type A inlet. Local two-phase flow parameters measured by a four-sensor conductivity probe in four bubbly and near bubbly flow conditions are analyzed. It is observed that vertical-downward two-phase flow has a characteristic center-peaked void profile as opposed to a wall-peaked profile as seen in vertical-upward flow. Furthermore, it is shown that the Type A inlet results in the most pronounced center-peaked void fraction profile, due to the coring phenomenon. Type B and Type C inlets

  18. Fixed Target Collisions at STAR

    Meehan, Kathryn C.

    2016-12-15

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. Previous results have been used to claim that the onset of deconfinement occurs at a center-of-mass energy of 7 GeV. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies of 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb potential analysis of Au + Au fixed-target collisions are presented and are found to be consistent with results from previous experiments. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared to published results from the AGS.

  19. Utilization of nitrogen fixing trees

    Brewbaker, J.L.; Beldt, R. van den; MacDicken, K.; Budowski, G.; Kass, D.C.L.; Russo, R.O.; Escalante, G.; Herrera, R.; Aranguren, J.; Arkcoll, D.B.; Doebereinger, J. (cord.)

    1983-01-01

    Six papers from the symposium are noted. Brewbaker, J.L., Beldt, R. van den, MacDicken, K. Fuelwood uses and properties of nitrogen-fixing trees, pp 193-204, (Refs. 15). Includes a list of 35 nitrogen-fixing trees of high fuelwood value. Budowski, G.; Kass, D.C.L.; Russo, R.O. Leguminous trees for shade, pp 205-222, (Refs. 68). Escalante, G., Herrera, R., Aranguren, J.; Nitrogen fixation in shade trees (Erythrina poeppigiana) in cocoa plantations in northern Venezuela, pp 223-230, (Refs. 13). Arkcoll, D.B.; Some leguminous trees providing useful fruits in the North of Brazil, pp 235-239, (Refs. 13). This paper deals with Parkia platycephala, Pentaclethra macroloba, Swartzia sp., Cassia leiandra, Hymenaea courbaril, dipteryz odorata, Inga edulis, I. macrophylla, and I. cinnamonea. Baggio, A.J.; Possibilities of the use of Gliricidia sepium in agroforestry systems in Brazil, pp 241-243; (Refs. 15). Seiffert, N.F.; Biological nitrogen and protein production of Leucaena cultivars grown to supplement the nutrition of ruminants, pp 245-249, (Refs. 14). Leucaena leucocephala cv. Peru, L. campina grande (L. leucocephala), and L. cunningham (L. leucocephalae) were promising for use as browse by beef cattle in central Brazil.

  20. Fixed-Target Electron Accelerators

    Brooks, William K.

    2001-01-01

    A tremendous amount of scientific insight has been garnered over the past half-century by using particle accelerators to study physical systems of sub-atomic dimensions. These giant instruments begin with particles at rest, then greatly increase their energy of motion, forming a narrow trajectory or beam of particles. In fixed-target accelerators, the particle beam impacts upon a stationary sample or target which contains or produces the sub-atomic system being studied. This is in distinction to colliders, where two beams are produced and are steered into each other so that their constituent particles can collide. The acceleration process always relies on the particle being accelerated having an electric charge; however, both the details of producing the beam and the classes of scientific investigations possible vary widely with the specific type of particle being accelerated. This article discusses fixed-target accelerators which produce beams of electrons, the lightest charged particle. As detailed in the report, the beam energy has a close connection with the size of the physical system studied. Here a useful unit of energy is a GeV, i.e., a giga electron-volt. (ne GeV, the energy an electron would have if accelerated through a billion volts, is equal to 1.6 x 10 -10 joules.) To study systems on a distance scale much smaller than an atomic nucleus requires beam energies ranging from a few GeV up to hundreds of GeV and more

  1. Distribution of variable vs fixed costs of hospital care.

    Roberts, R R; Frutos, P W; Ciavarella, G G; Gussow, L M; Mensah, E K; Kampe, L M; Straus, H E; Joseph, G; Rydman, R J

    1999-02-17

    Most strategies proposed to control the rising cost of health care are aimed at reducing medical resource consumption rates. These approaches may be limited in effectiveness because of the relatively low variable cost of medical care. Variable costs (for medication and supplies) are saved if a facility does not provide a service while fixed costs (for salaried labor, buildings, and equipment) are not saved over the short term when a health care facility reduces service. To determine the relative variable and fixed costs of inpatient and outpatient care for a large urban public teaching hospital. Cost analysis. A large urban public teaching hospital. All expenditures for the institution during 1993 and for each service were categorized as either variable or fixed. Fixed costs included capital expenditures, employee salaries and benefits, building maintenance, and utilities. Variable costs included health care worker supplies, patient care supplies, diagnostic and therapeutic supplies, and medications. In 1993, the hospital had nearly 114000 emergency department visits, 40000 hospital admissions, 240000 inpatient days, and more than 500000 outpatient clinic visits. The total budget for 1993 was $429.2 million, of which $360.3 million (84%) was fixed and $68.8 million (16%) was variable. Overall, 31.5% of total costs were for support expenses such as utilities, employee benefits, and housekeeping salaries, and 52.4% included direct costs of salary for service center personnel who provide services to individual patients. The majority of cost in providing hospital service is related to buildings, equipment, salaried labor, and overhead, which are fixed over the short term. The high fixed costs emphasize the importance of adjusting fixed costs to patient consumption to maintain efficiency.

  2. Improved Landau gauge fixing and discretisation errors

    Bonnet, F.D.R.; Bowman, P.O.; Leinweber, D.B.; Richards, D.G.; Williams, A.G.

    2000-01-01

    Lattice discretisation errors in the Landau gauge condition are examined. An improved gauge fixing algorithm in which O(a 2 ) errors are removed is presented. O(a 2 ) improvement of the gauge fixing condition displays the secondary benefit of reducing the size of higher-order errors. These results emphasise the importance of implementing an improved gauge fixing condition

  3. Nuclear research reactor IEA-R1 heat exchanger inlet nozzle flow - a preliminary study

    Angelo, Gabriel; Andrade, Delvonei Alves de; Fainer, Gerson; Angelo, Edvaldo

    2009-01-01

    As a computational fluid mechanics training task, a preliminary model was developed. ANSYS-CFX R code was used in order to study the flow at the inlet nozzle of the heat exchanger of the primary circuit of the nuclear research reactor IEA-R1. The geometry of the inlet nozzle is basically compounded by a cylinder and two radial rings which are welded on the shell. When doing so there is an offset between the holes through the shell and the inlet nozzle. Since it is not standardized by TEMA, the inlet nozzle was chosen for a preliminary study of the flow. Results for the proposed model are presented and discussed. (author)

  4. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase II

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  5. Cook Inlet and Kenai Peninsula, Alaska ESI: M_MAMPT (Marine Mammal Points)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for seals and sea lions in Cook Inlet and Kenai Peninsula, Alaska. Vector points in this data set represent locations...

  6. Fuel effects on the stability of turbulent flames with compositionally inhomogeneous inlets

    Guiberti, T. F.; Juddoo, M.; Lacoste, Deanna; Dunn, M. J.; Roberts, William L.; Masri, A. R.

    2016-01-01

    This paper reports an analysis of the influence of fuels on the stabilization of turbulent piloted jet flames with inhomogeneous inlets. The burner is identical to that used earlier by the Sydney Group and employs two concentric tubes within

  7. Analysis of DC control in double-inlet GM type pulse tube refrigerators for detectors

    Du, B. Y.

    2016-10-01

    Pulse tube refrigerators have demonstrated many advantages with respect to temperature stability, vibration, reliability and lifetime among cryo-coolers for detectors. Double-inlet type pulse tube refrigerators are popular in GM type pulse tube refrigerators. The single double-inlet valve may introduce DC flow in refrigerator, which deteriorates the performance of pulse tube refrigerator. One new type of DC control mode is introduced in this paper. Two parallel-placed needle valves with opposite direction named double-valve configuration, instead of single double-inlet valve, are used in our experiment to reduce the DC flow. With two double-inlet operating, the lowest cold end temperature of 18.1K and a coolant of 1.2W@20K have been obtained. It has proved that this method is useful for controlling DC flow of the pulse tube refrigerators, which is very important to understand the characters of pulse tube refrigerators for detectors.

  8. Geologic framework and petroleum systems of Cook Inlet basin, south-central Alaska

    LePain, D.L.; Stanley, R.G.; Helmold, K.P.; Shellenbaum, D.P.; Stone, D.M.; Hite, D.M.

    2013-01-01

    This report provides a comprehensive overview of the stratigraphy, structure, tectonics, and petroleum systems of the Cook Inlet basin, an important oil- and gas-producing region in south-central Alaska.

  9. Cook Inlet and Kenai Peninsula, Alaska ESI: M_MAMMAL (Marine Mammal Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for marine mammals in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  10. Cook Inlet and Kenai Peninsula, Alaska ESI: RIPS (Rip Current Lines)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of rip currents in Cook Inlet, Alaska. Vector lines in the data set represent rip zone locations. Location-specific type and source...

  11. Thermal stratification built up in hot water tank with different inlet stratifiers

    Dragsted, Janne; Furbo, Simon; Dannemand, Mark

    2017-01-01

    Thermal stratification in a water storage tank can strongly increase the thermal performance of solar heating systems. Thermal stratification can be built up in a storage tank during charge, if the heated water enters through an inlet stratifier. Experiments with a test tank have been carried out...... in order to elucidate how well thermal stratification is established in the tank with differently designed inlet stratifiers under different controlled laboratory conditions. The investigated inlet stratifiers are from Solvis GmbH & Co KG and EyeCular Technologies ApS. The inlet stratifier from Solvis Gmb...... for Solvis GmbH & Co KG had a better performance at 4 l/min. In the intermediate charge test the stratifier from EyeCular Technologies ApS had a better performance in terms of maintaining the thermal stratification in the storage tank while charging with a relative low temperature. [All rights reserved...

  12. Viscous flow considerations in the design of the Busemann hypersonic air inlet

    Walsh, P.C.; Tahir, R.B.; Molder, S.

    2002-01-01

    A cost effective means of traveling to a low earth orbit is using an aircraft that relies on air-breathing engine technology for most of its trajectory while in the atmosphere. The scramjets that would be used to provide propulsion require inlet air diffusion with minimal total pressure losses to maintain efficiency. The Busemann inlet was designed using inviscid flow assumptions specifically for such purposes. This paper presents an investigation into the effects of viscosity on inlet performance in terms of static pressure rise and internal shockwave configuration. The viscous effects within the inlet can alter the design pressure ratio as much as 50%. It was shown that a correction based on a displacement radius calculation was sufficient to restore the static pressure performance of the inviscid design. An improvement of 16% in total pressure losses was observed with the corrected Busemann profile. Results are compared to experimentally determined surface pressure values. (author)

  13. CREEK Project's Oyster Biomass Database for Eight Creeks in the North Inlet Estuary, South Carolina

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A group of eight tidal creeks dominated by oysters, Crassostrea virginica, in North Inlet Estuary, South Carolina, USA were studied using a replicated BACI (Before -...

  14. Evaluation of turbine microjet engine operating parameters in conditions conducive to inlet freezing

    Markowski Jaroslaw

    2017-01-01

    Full Text Available The problem of turbine microjet engine operation is related to flight conditions of unmanned aircraft. These flights are often performed at low altitudes, where, in autumn and winter conditions, the air can be characterized by high humidity and low temperature. Such operating conditions may cause freezing the turbine engine inlet. In particular, this problem may be related to microengines, which most often are not equipped with a de-icing installation. Frosting of the inlet violates the air flow conditions at the engine inlet and may cause unstable operation and even outages, which eventually may lead to a loss of aircraft’s stability and breakdown. Therefore, an attempt was made to evaluate the changes in operational parameters of the turbine microjet engine under conditions leading to the freezing of the inlet. The engine test was performed in stationary conditions and the analysis of the obtained results are presented in this article.

  15. Environmental Sensitivity Index (ESI) Atlas: Cook Inlet, Alaska, maps and geographic information systems (NODC Accession 0046027)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) data for Cook Inlet and Kenai Peninsula, Alaska. ESI data characterize estuarine environments and...

  16. AFSC/NMML: Beluga whale Counts from Aerial Surveys in Cook Inlet, Alaska, 1993-2014

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory conducted aerial surveys to monitor the abundance and distribution of beluga whales in Cook Inlet, Alaska. This database...

  17. Cook Inlet and Kenai Peninsula, Alaska ESI: ICE (Ice Extent Lines)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of ice extent in Cook Inlet, Alaska. Vector lines in the data set represent 50 percent ice coverage. Location-specific type and...

  18. AFSC/NMML: Cook Inlet Beluga Opportunistic Sightings, 1975 to 2015

    National Oceanic and Atmospheric Administration, Department of Commerce — As a part of National Marine Fisheries Service (NMFS) management of the endangered Cook Inlet beluga whale population, a database of opportunistic beluga whale...

  19. Cook Inlet Beluga Opportunistic Sightings, 1975 to 2015 (NCEI Accession 0142326)

    National Oceanic and Atmospheric Administration, Department of Commerce — As a part of National Marine Fisheries Service (NMFS) management of the endangered Cook Inlet beluga whale population, a database of opportunistic beluga whale...

  20. Cook Inlet and Kenai Peninsula, Alaska ESI: MGT (Management Area Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains management area data for communities, wildlife refuges, and National, State, and regional parks in Cook Inlet and Kenai Peninsula, Alaska....

  1. Cook Inlet and Kenai Peninsula, Alaska ESI: HYDRO (Hydrography Lines and Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing coastal hydrography used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet...

  2. AFSC/NMML: Beluga whale aerial survey in Cook Inlet, Alaska, 1993-2014

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted aerial counts of Cook Inlet beluga whales (Delphinapterus leucas) from 1993 to 2014 (excluding 2013)....

  3. Telemetry data from satellite tags deployed on harbor seals in Cook Inlet, Alaska

    National Oceanic and Atmospheric Administration, Department of Commerce — Between 2004 and 2006 we conducted four harbor seal tagging trips in Cook Inlet during the months of October and May. In total, we captured and released 93 harbor...

  4. Cook Inlet and Kenai Peninsula, Alaska ESI: ESI (Environmental Sensitivity Index Shoreline Types - Polygons and Lines)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats of Cook Inlet and Kenai Peninsula, Alaska, classified according to...

  5. Settling of fixed erythrocyte suspension droplets

    Omenyi, S. N.; Snyder, R. S.

    1983-01-01

    It is pointed out that when particles behave collectively rather than individually, the fractionation of micron-size particles on the basis of size, density, and surface characteristics by centrifugation and electrophoresis is hindered. The formation and sedimentation of droplets containing particles represent an extreme example of collective behavior and pose a major problem for these separation methods when large quantities of particles need to be fractionated. Experiments are described that measure droplet sizes and settling rates for a variety of particles and droplets. Expressions relating the particle concentration in a drop to measurable quantities of the fluids and particles are developed. The number of particles in each droplet is then estimated, together with the effective droplet density. Red blood cells from different animals fixed in glutaraldehyde provide model particle groups.

  6. Adhesives for fixed orthodontic brackets.

    Mandall, Nicky A; Hickman, Joy; Macfarlane, Tatiana V; Mattick, Rye Cr; Millett, Declan T; Worthington, Helen V

    2018-04-09

    Bonding of orthodontic brackets to teeth is important to enable effective and efficient treatment with fixed appliances. The problem is bracket failure during treatment which increases operator chairside time and lengthens treatment time. A prolonged treatment is likely to increase the oral health risks of orthodontic treatment with fixed appliances one of which is irreversible enamel decalcification. This is an update of the Cochrane Review first published in 2003. A new full search was conducted on 26 September 2017 but no new studies were identified. We have only updated the search methods section in this new version. The conclusions of this Cochrane Review remain the same. To evaluate the effects of different orthodontic adhesives for bonding. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 26 September 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8) in the Cochrane Library (searched 26 September 2017), MEDLINE Ovid (1946 to 26 September 2017), and Embase Ovid (1980 to 26 September 2017). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing two different adhesive groups. Participants were patients with fixed orthodontic appliances. The interventions were adhesives that bonded stainless steel brackets to all teeth except the molars. The primary outcome was debond or bracket failure. Data were recorded on decalcification as a secondary outcome, if present. Information regarding methods, participants, interventions, outcome measures and results were extracted in

  7. Euler Calculations at Off-Design Conditions for an Inlet of Inward Turning RBCC-SSTO Vehicle

    Takashima, N.; Kothari, A. P.

    1998-01-01

    The inviscid performance of an inward turning inlet design is calculated computationally for the first time. Hypersonic vehicle designs based on the inward turning inlets have been shown analytically to have increased effective specific impulse and lower heat load than comparably designed vehicles with two-dimensional inlets. The inward turning inlets are designed inversely from inviscid stream surfaces of known flow fields. The computational study is performed on a Mach 12 inlet design to validate the performance predicted by the design code (HAVDAC) and calculate its off-design Mach number performance. The three-dimensional Euler equations are solved for Mach 4, 8, and 12 using a software package called SAM, which consists of an unstructured mesh generator (SAMmesh), a three-dimensional unstructured mesh flow solver (SAMcfd), and a CAD-based software (SAMcad). The computed momentum averaged inlet throat pressure is within 6% of the design inlet throat pressure. The mass-flux at the inlet throat is also within 7 % of the value predicted by the design code thereby validating the accuracy of the design code. The off-design Mach number results show that flow spillage is minimal, and the variation in the mass capture ratio with Mach number is comparable to an ideal 2-D inlet. The results from the inviscid flow calculations of a Mach 12 inward turning inlet indicate that the inlet design has very good on and off-design performance which makes it a promising design candidate for future air-breathing hypersonic vehicles.

  8. The Atlantic Coast of Maryland, Sediment Budget Update: Tier 2, Assateague Island and Ocean City Inlet

    2016-06-01

    111 – Rivers and Harbors Act), the navigational structures at the Ocean City Inlet, and a number of Federally authorized channels (Figure 1). Reed...Tier 2, Assateague Island and Ocean City Inlet by Ernest R. Smith, Joseph C. Reed, and Ian L. Delwiche PURPOSE: This Coastal and Hydraulics...of the Atlantic Ocean shoreline within the U.S. Army Corps of Engineers (USACE) Baltimore District’s Area of Responsibility, which for coastal

  9. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    Xiang, J.; Siddiqui, A.H.; Meng, H.

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  10. Prediction of the Inlet Nozzle Velocity Profiles for the CANDU-6 Moderator Analysis

    Yoon, Churl; Park, Joo Hwan

    2006-01-01

    For the moderator analysis of the CANDU reactors in Korea, predicting local moderator subcooling in the Calandria vessels is one of the main concerns for the estimation of heat sink capability of moderator under LOCA transients. The moderator circulation pattern is determined by the combined forces of the inlet jet momentum and the buoyancy flow. Even though the inlet boundary condition plays an important role in determining the moderator circulations, no measured data of detailed inlet velocity profiles is available. The purpose of this study is to produce the velocity profiles at the inlet nozzles by a CFD simulation. To produce the velocity vector fields at the inlet nozzle surfaces, the internal flows in the nozzle assembly were simulated by using a commercial CFD code, CFX-5.7. In the reference, the analytical capability of CFX-5.7 had been estimated by a validation of the CFD code against available experimental data for separate flow phenomena. Various turbulence models and grid spacing had been also tested. In the following section, the interface treatment between the computational domains would be explained. In section 3, the inlet nozzle flow through the CANDU moderator nozzle assembly was predicted by using the obtained technology of the CFD simulation

  11. Influence of inlet water on the biotic and abiotic variables in a fish pond

    L. H. Sipaúba-Tavares

    Full Text Available Abstract The effects of treated and untreated water inlets with macrophytes on the improvement of water quality and zooplankton community were evaluated in a fish pond with continuous water flow. Water and zooplankton samples were retrieved at four sites during nine months. There were differences (p<0.01 between inlet water from fish pond and inlet water from canal with macrophytes, featuring higher concentrations of nutrient load, mainly TAN and TP in the former. The inlet water from fish pond contained a higher number of abundant species (9 species, whilst the water supply from the canal with macrophytes had a greater richness (31 species of zooplankton species. Results showed that inlet water without macrophytes directly affected the characteristics of the water column and the dominance of zooplankton species such as Thermocyclops decipiens, and greater abundance of Rotifera species. Since aquatic plants in the inlet water of fish pond analyzed showed lower allochthonous material loads from the previous fish pond, the management adopted with macrophytes may be applied to avoid eutrophication risks, common in farm ponds.

  12. Evaluation of PM-10 commercial inlets for new surveillance air sampler

    Langer, G.

    1986-01-01

    The inlet for the present Rock Flats Plant surveillance sampler does not meet the new but still tentative PM-10 (<10-μm particle mass) criterion for sampling the hazardous fraction of airborne dust. Since this criterion relates mainly to non-radioactive emissions, DOE and EPA are presently in the process of promulgating emission guidelines specifically for non-reactor DOE nuclear facilities. The authors present approach is to select a commercial inlet and modify its, if necessary, to meet the PM-10 criterion, keeping in mind that they may have to recover the dust collected in the inlet. There is no EPA-approved PM-10 inlet design; instead, EPA issued a performance specification. As a nuclear operation, Rocky Flats has to sample continuously to ensure no period remains unmonitored, instead of every sixth day, as set forth by EPA for non-nuclear installations. During this study period, the authors developed an inlet evaluation methodology to meet the above, anticipated EPA requirements. Also, they started testing two potential inlets. 6 references, 2 figures, 1 table

  13. Dynamics of the inlet system of a four-stroke engine

    Boden, R H; Schecter, Harry

    1944-01-01

    Tests were run on a single-cylinder and a multicylinder four-stroke engine in order to determine the effect of the dynamics of the inlet system upon indicated mean effective pressure. Tests on the single-cylinder engine were made at various speeds, inlet valve timings, and inlet pipe lengths. These tests indicated that the indicated mean effective pressure could be raised considerably at any one speed by the use of a suitably long inlet pipe. Tests at other speeds with this length of pipe showed higher indicated mean effective pressure than with a very short pipe, although not so high as could be obtained with the pipe length adjusted for each speed. A general relation was discovered between optimum time of inlet valve closing and pipe length; namely, that longer pipes require later inlet valve closing in order to be fully effective. Tests were also made on three cylinders connected to a single pipe. With this arrangement, increased volumetric efficiency at low speed was obtainable by using a long pipe, but only with a sacrifice of volumetric efficiency at high speed. Volumetric efficiency at high speed was progressively lower as the pipe length was increased.

  14. Investigation of Unsteady Flow Interaction Between an Ultra-Compact Inlet and a Transonic Fan

    Hah, Chunill; Rabe, Douglas; Scribben, Angie

    2015-01-01

    In the present study, unsteady flow interaction between an ultra-compact inlet and a transonic fan stage is investigated. Future combat aircraft require ultra-compact inlet ducts as part of an integrated, advanced propulsion system to improve air vehicle capability and effectiveness to meet future mission needs. The main purpose of the study is to advance the current understanding of the flow interaction between two different ultra-compact inlets and a transonic fan for future design applications. Both URANS and LES approaches are used to calculate the unsteady flow field and are compared with the available measured data. The present study indicates that stall inception is mildly affected by the distortion pattern generated by the inlet with the current test set-up. The numerical study indicates that the inlet distortion pattern decays significantly before it reaches the fan face for the current configuration. Numerical results with a shorter distance between the inlet and fan show that counter-rotating vortices near the rotor tip due to the serpentine diffuser affects fan characteristics significantly.

  15. A hybrid CFD/characteristics method for fast characterization of hypersonic blunt forebody/inlet flow

    Gao, WenZhi; Li, ZhuFei; Yang, JiMing

    2015-10-01

    A hybrid CFD/characteristic method (CCM) was proposed for fast design and evaluation of hypersonic inlet flow with nose bluntness, which targets the combined advantages of CFD and method of characteristics. Both the accuracy and efficiency of the developed CCM were verified reliably, and it was well demonstrated for the external surfaces design of a hypersonic forebody/inlet with nose bluntness. With the help of CCM method, effects of nose bluntness on forebody shock shapes and the flowfield qualities which dominate inlet performance were examined and analyzed on the two-dimensional and axisymmetric configurations. The results showed that blunt effects of a wedge forebody are more substantial than that of related cone cases. For a conical forebody with a properly blunted nose, a recovery of the shock front back to that of corresponding sharp nose is exhibited, accompanied with a gradually fading out of entropy layer effects. Consequently a simplification is thought to be reasonable for an axisymmetric inlet with a proper compression angle, and a blunt nose of limited radius can be idealized as a sharp nose, as the spillage and flow variations at the entrance are negligible, even though the nose scale increases to 10% cowl lip radius. Whereas for two-dimensional inlets, the blunt effects are substantial since not only the inlet capturing/starting capabilities, but also the flow uniformities are obviously degraded.

  16. Phycocyanin stability in microcapsules processed by spray drying method using different inlet temperature

    Purnamayati, L.; Dewi, EN; Kurniasih, R. A.

    2018-02-01

    Phycocyanin is natural blue colorant which easily damages by heat. The inlet temperature of spray dryer is an important parameter representing the feature of the microcapsules.The aim of this study was to investigate the phycocyanin stability of microcapsules made from Spirulina sp with maltodextrin and κ-Carrageenan as the coating material, processed by spray drying method in different inlet temperature. Microcapsules were processed in three various inlet temperaturei.e. 90°C, 110°C, and 130°C, respectively. The results indicated that phycocyanin microcapsule with 90°C of inlet temperature produced the highest moisture content, phycocyanin concentration and encapsulation efficiency of 3,5%, 1,729% and 29,623%, respectively. On the other hand, the highest encapsulation yield was produced by 130°C of theinlet temperature of 29,48% and not significantly different with 110°C. The results of Scanning Electron Microscopy (SEM) showed that phycocyanin microcapsules with 110°C of inlet temperature produced the most rounded shape. To sum up, 110°C was the best inlet temperature to phycocyanin microencapsulation by the spray dryer.

  17. Numerical simulation of progressive BWR fuel inlet orifices

    Sara Lundgren; Hernan Tinoco; Aleksander Pohl; Wiktor Frid

    2005-01-01

    Full text of publication follows: A 'progressive' orifice is characterized by an edge-shaped hole that gives a Reynolds number dependent resistance coefficient. For Reynolds numbers smaller than a critical one, the resistance coefficient has a high constant value that drops to a much lower value for Reynolds numbers greater than this critical value. A similar effect is widely known for external flows around bodies of different shapes, i. e. spheres, cylinders, etc., and the sudden drop in drag coefficient is due to the shift from laminar to turbulent boundary-layer flow. Experimentally, progressive orifices have been investigated under high-pressure and high-temperature conditions by Akiba et al. (2001) for a reduced set of geometrical parameters. Using the sparse experimental data, a core stability study was carried out by Forsmaks Kraftgrupp AB that showed an improvement in core stability but without the expected reduction in pump power at normal operation. The reason for this partial success was the impossibility of optimizing the fuel inlet pressure drop owing to the limited amount of available data. Due to the high costs associated with the experimental generation of high-pressure, high-temperature data, it was considered that, if possible, the lacking data could be generated numerically at much lower cost. Therefore, the present work deals with the possibility of numerically simulate the flow through progressive orifices, and with the conditions under which to reproduce and generate resistance coefficient data by means of a commercial CFD-code. The results obtained with a two-dimensional, axisymmetric approximation show that Reynolds Averaged Navier-Stokes (RANS) turbulence models are able to qualitatively capture the physics of the phenomenon but with an earlier transition to turbulent boundary-layer flow and with an underestimation of the resistance coefficient by approximately 20 %. This underestimation of the resistance coefficient is related to the two

  18. Numerical simulation of progressive BWR fuel inlet orifices

    Sara Lundgren; Hernan Tinoco [Forsmarks Kraftgrupp AB, 742 03 Oesthammar (Sweden); Aleksander Pohl; Wiktor Frid [The Royal Institute of Technology, Dept. Energy Technology, SE-100 44 Stockholm (Sweden)

    2005-07-01

    Full text of publication follows: A 'progressive' orifice is characterized by an edge-shaped hole that gives a Reynolds number dependent resistance coefficient. For Reynolds numbers smaller than a critical one, the resistance coefficient has a high constant value that drops to a much lower value for Reynolds numbers greater than this critical value. A similar effect is widely known for external flows around bodies of different shapes, i. e. spheres, cylinders, etc., and the sudden drop in drag coefficient is due to the shift from laminar to turbulent boundary-layer flow. Experimentally, progressive orifices have been investigated under high-pressure and high-temperature conditions by Akiba et al. (2001) for a reduced set of geometrical parameters. Using the sparse experimental data, a core stability study was carried out by Forsmaks Kraftgrupp AB that showed an improvement in core stability but without the expected reduction in pump power at normal operation. The reason for this partial success was the impossibility of optimizing the fuel inlet pressure drop owing to the limited amount of available data. Due to the high costs associated with the experimental generation of high-pressure, high-temperature data, it was considered that, if possible, the lacking data could be generated numerically at much lower cost. Therefore, the present work deals with the possibility of numerically simulate the flow through progressive orifices, and with the conditions under which to reproduce and generate resistance coefficient data by means of a commercial CFD-code. The results obtained with a two-dimensional, axisymmetric approximation show that Reynolds Averaged Navier-Stokes (RANS) turbulence models are able to qualitatively capture the physics of the phenomenon but with an earlier transition to turbulent boundary-layer flow and with an underestimation of the resistance coefficient by approximately 20 %. This underestimation of the resistance coefficient is related to

  19. Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures

    Meldrum, J. L.; Jamieson, H. E.; Dyke, L. D.

    2001-10-01

    An experiment was undertaken to determine if encapsulation in permafrost of acid-generating sulphidic tailings from a Ni-Cu mine on the shores of Hudson Bay in Nunavut will maintain the tailings and their saline pore water in a chemically inert state. The experiment involved collection of tailings material and pore water samples three years after burial, followed by long-term thermal monitoring. Tailings were studied at temperatures between +30 degrees C and -10 degrees C. Oxygen consumption was measured directly to determine the effect of low temperatures on oxidation rate. Significant oxidation was observed at +30 degrees C, which was substantially reduced at lower temperatures. At -10 degrees C oxygen consumption was below the detection limit. The highest measured oxygen flux correlated with a temperature increase of one degree C, which is consistent with exothermic sulphide oxidation reactions. The experiment showed that freezing in Rankin Inlet is progressing and tailings will be ice-bonded approximately 15 years after burial. 30 refs., 3 tabs. 6 figs.

  20. Oxide deposition in the orifices of AGR boiler inlet ferrule assemblies

    Thomas, D.M.

    1988-08-01

    In experiments designed to study the erosion-corrosion behaviour of AGR boiler inlet ferrules using the CERL high velocity circulating isothermal water rig, oxide deposition was frequently found within the flow control orifices. The present investigation was carried out as a preliminary to a programme of experiments addressed specifically to this problem. Analysis shows the deposits to be predominantly magnetite (or possible maghemite) with traces of α-haematite. Calculations indicate that the maximum rate of magnetite deposition is mass transfer limited, although in some experiments no deposition occurred in cases where mass transfer would have allowed substantial deposition. Thus the occurrence of deposition is thought to depend on the rig potential as this varies with experimental conditions. In these experiments the surface potential is not found to be governed by the hydrogen level. Metallographic cross-sections through the ferrule control bores show the deposits to be found in regions of separated flow, and the flow markings in the deposits show that the flow is turbulent in these zones. The exact morphology is thought to be influenced by machining marks within the control bore. (author)

  1. Effect of fuel string relocation on the consequences of postulated inlet header LBLOCA in KANUPP reactor

    Ahmed, I.; Chow, H.C.; Younis, M.H.

    1996-01-01

    An investigation aimed at determining the effect of fuel string relocation on reactivity excursion and power pulse following a hypothetical Large Break Loss of Coolant Accident in KANUPP reactor is reported. The assessment of reactivity insertion was performed making use of global (reactor) core analysis computer code RFSP. The reactor kinetics module CERBERUS of the RFSP code and the SOPHT (thermal-hydraulics code) were subsequently employed for the neutronic transient analysis. The effect was evaluated in context of determining the adequacy of moderator dump shutdown system. Because of the presence of the gap between the inlet shield plug and the fuel string, the fuel bundles may shift in such a manner that low-irradiated fuel is moved towards the core centre. This represents an additional reactivity increase to be accounted for in the analysis. The reactivity excursion, however, is alleviated by an earlier reactor trip. The net impact is that the energy deposited in the maximum rated fuel pencil is increased from 56% of the 960 kJ/kg fuel-centre-line melting limit to 63%. The result demonstrated the adequacy of the shutdown system against the maximum credible accident event. (author)

  2. Development of acoustic leak detection and localization methods for inlet piping of fugen nuclear power plant

    Shimanskiy, Sergey; Iijima, Takashi; Naoi, Yosuke

    2004-01-01

    The development work carried out on Fugen NPP is focused on detection of a small leakage on the reactor's inlet feeder pipes at an early stage by an acoustic leak detection method with usage of high-temperature resistant microphones. Specifically, the leak rate of 0.046m 3 /h has been chosen as a target detection capability for this system. A cross-correlation technique has been studied for leak detection under low signal-noise ratios. The study shows that the sound diffusion on piping causes distortion of leak signals that results in their low correlation. A leak-location estimator and multi-channel correlation value, associated with estimated leak position, have been employed to detect such low-correlated leak signals. A method based on cross-correlation of signal spectral components has been proposed to deal with non-stationary leak signals. Joint-Time-Frequency-Analysis has been applied to analyze such signals, whilst a Wavelet decomposition technique has been used to extract their short-term spectral fluctuations. Since the spectral components are less affected by signal distortion, they provide higher correlation value and can be applied for leak detection under lower signal-noise ratios. The possibility of detecting and locating a small leakage by the methods proposed has been demonstrated by a number of simulation tests conducted on the Fugen NPP site. (author)

  3. Fluid flow and heat transfer of nanofluids in microchannel heat sink with V-type inlet/outlet arrangement

    Ayoub Abdollahi

    2017-03-01

    Full Text Available The fluid flow and heat transfer characteristics of laminar nanofluid flow in microchannel heat sink (MCHS with V-Type inlet/outlet arrangement are numerically studied. A constant heat flux boundary condition is applied on the base plate of MCHS and all the other surfaces of MCHS are insulated. Four different kinds of nanofluids are utilized as working fluids which are SiO2, Al2O3, ZnO and CuO dispersed in pure water as a base fluid. Three different volume fractions of 1%, 1.5% and 2% and three distinctive nanoparticle diameters of 30 nm, 40 nm and 60 nm were employed. The results specify that the SiO2 nanofluid has the uppermost heat transfer rate compared to other tested nanofluids. Increasing the nanoparticles volume fraction together with decreasing the nanoparticles diameter enhances the Nusselt number value. The pressure drop coefficient did not change significantly by using nanofluid with various volume fractions and varied nanoparticle diameters. Moreover, the results indicate that nanofluid can enhance the performance of MCHS with V-shaped inlet/outlet arrangement.

  4. Laser assisted removal of fixed contamination from metallic substrate

    Kumar, Aniruddha; Prasad, Manisha; Prakash, Tej; Shail, Shailini; Bhatt, R.B.; Behere, P.G.; Mohd Afzal; Kumar, Arun; Biswas, D.J.

    2015-01-01

    A single mode pulsed fiber laser was used to remove fixed contamination from stainless steel substrate by ablation. Samples were simulated by electro-deposition technique with 232 U as the test contaminant. Laser power, repetition rate, laser beam scanning speed and number of passes were optimised to obtain the desired ablation depth in the substrate. Ablation depth varying between few microns to few hundreds of microns could be achieved through careful control of these processing parameters. The absence of any activity in laser treated samples provided experimental signature of the efficacy of the laser assisted removal of fixed contamination. (author)

  5. Fixed target beauty physics from Tevatron to SSC (E771)

    Lau, K.

    1992-01-01

    The E771 beauty experiment at Fermilab is described. The Super Fixed Target Beauty Facility (SFT) proposal to perform fixed target beauty physics at the SSC is a natural evolution. The unique features of SFT include crystal channeling extraction from the SSC main ring, which allows the experiment to operate concurrently with the collider experiments. The slow extraction rate (≅2x10 8 protons/s) does not limit the lifetime of the stored beams. The proposed beauty spectrometer and its capability in CP violation studies are described. (author) 19 refs.; 2 figs.; 2 tabs

  6. A modeling study of tidal energy extraction and the associated impact on tidal circulation in a multi-inlet bay system of Puget Sound

    Wang, Taiping; Yang, Zhaoqing

    2017-12-01

    Previous tidal energy projects in Puget Sound have focused on major deep channels such as Admiralty Inlet that have a larger power potential but pose greater technical challenges than minor tidal channels connecting to small sub-basins. This paper focuses on the possibility of extracting energy from minor tidal channels by using a hydrodynamic model to quantify the power potential and the associated impact on tidal circulation. The study site is a multi-inlet bay system connected by two narrow inlets, Agate Pass and Rich Passage, to the Main Basin of Puget Sound. A three-dimensional hydrodynamic model was applied to the study site and calibrated for tidal elevations and currents. We examined three energy extraction scenarios in which turbines were deployed in each of the two passages and concurrently in both. Extracted power rates and associated changes in tidal elevation, current, tidal flux, and residence time were examined. Maximum instantaneous power rates reached 250 kW, 1550 kW, and 1800 kW, respectively, for the three energy extraction scenarios. The model suggests that with the proposed level of energy extraction, the impact on tidal circulation is very small. It is worth investigating the feasibility of harnessing tidal energy from minor tidal channels of Puget Sound.

  7. Currency Boards; The Ultimate Fix?

    Atish R. Ghosh

    1998-01-01

    The growing integration of world capital markets has made it fashionable to argue that only extreme exchange rate regimes are sustainable. Short of adopting a common currency, currency board arrangements represent the most extreme form of exchange rate peg. This paper compares the macroeconomic performance of countries with currency boards to those with other forms of pegged exchange rate regime. Currency boards are indeed associated with better inflation performance, even allowing for potent...

  8. Large Eddy Simulation and the effect of the turbulent inlet conditions in the mixing Tee

    Ndombo, Jean-Marc; Howard, Richard J.A.

    2011-01-01

    Highlights: → LES of Tee junctions can easily reproduce the bulk flow. → The presence or absence of a turbulent inlet condition has an affect on the wall heat transfer. → The maximum heat transfer moves 1 cm and reduces by 10% when a turbulent inlet is used. - Abstract: Thermal fatigue in Pressurized Water Reactor plants has been found to be very acute in some hot/cold Tee junction mixing zones. Large Eddy Simulation (LES) can be used to capture the unsteadiness which is responsible for the large mechanical stresses associated with thermal fatigue. Here one LES subgrid model is studied, namely the Dynamic Smagorinsky model. This paper has two goals. The first is to demonstrate some results obtained using the EDF R and D Code Saturne applied to the Vattenfall Tee junction benchmark (version 2006) and the second is to look at the effect of including synthetic turbulence at the Tee junction pipe inlets. The last goal is the main topic of this paper. The Synthetic Eddy Method is used to create the turbulent inlet conditions and is applied to two kinds of grids. One contains six million cells and the other ten million. The addition of turbulence at the inlet does not seem to have much effect on the bulk flow and all computations are in good agreement with the experimental data. However, the inlet turbulence does have an effect on the near wall flow. All cases show that the wall temperature fluctuation and the wall temperature/velocity correlation are not the same when a turbulent inlet condition is used. Inclusion of the turbulent inlet condition moves the downstream location of the maximum temperature/velocity correlation by 1 cm and reduces its magnitude by 10%. This result is very important because the temperature/velocity correlation is closely related to the turbulent heat transfer in the flow, which is in turn responsible for the mechanical stresses on the structure. Finally we have studied in detail the influence of the turbulent inlet condition just

  9. Asteroid body-fixed hovering using nonideal solar sails

    Zeng, Xiang-Yuan; Jiang, Fang-Hua; Li, Jun-Feng

    2015-01-01

    The problem of body-fixed hovering over an asteroid using a compact form of nonideal solar sails with a controllable area is investigated. Nonlinear dynamic equations describing the hovering problem are constructed for a spherically symmetric asteroid. Numerical solutions of the feasible region for body-fixed hovering are obtained. Different sail models, including the cases of ideal, optical, parametric and solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed. The required orientations for the sail and their corresponding variable lightness numbers are given for different hovering radii to identify the feasible region of the body-fixed hovering. An attractive scenario for a mission is introduced to take advantage of solar sail hovering. (paper)

  10. Getting physical to fix pharma

    Connelly, Patrick R.; Vuong, T. Minh; Murcko, Mark A.

    2011-09-01

    Powerful technologies allow the synthesis and testing of large numbers of new compounds, but the failure rate of pharmaceutical R&D remains very high. Greater understanding of the fundamental physical chemical behaviour of molecules could be the key to greatly enhancing the success rate of drug discovery.

  11. Fixed or adapted conditioning intensity for repeated conditioned pain modulation.

    Hoegh, M; Petersen, K K; Graven-Nielsen, T

    2017-12-29

    Aims Conditioned pain modulation (CPM) is used to assess descending pain modulation through a test stimulation (TS) and a conditioning stimulation (CS). Due to potential carry-over effects, sequential CPM paradigms might alter the intensity of the CS, which potentially can alter the CPM-effect. This study aimed to investigate the difference between a fixed and adaptive CS intensity on CPM-effect. Methods On the dominant leg of 20 healthy subjects the cuff pressure detection threshold (PDT) was recorded as TS and the pain tolerance threshold (PTT) was assessed on the non-dominant leg for estimating the CS. The difference in PDT before and during CS defined the CPM-effect. The CPM-effect was assessed four times using a CS with intensities of 70% of baseline PTT (fixed) or 70% of PTT measured throughout the session (adaptive). Pain intensity of the conditioning stimulus was assessed on a numeric rating scale (NRS). Data were analyzed with repeated-measures ANOVA. Results No difference was found comparing the four PDTs assessed before CSs for the fixed and the adaptive paradigms. The CS pressure intensity for the adaptive paradigm was increasing during the four repeated assessments (P CPM-effect was higher using the fixed condition compared with the adaptive condition (P CPM paradigms using a fixed conditioning stimulus produced an increased CPM-effect compared with adaptive and increasing conditioning intensities.

  12. Coupled Analysis of an Inlet and Fan for a Quiet Supersonic Jet

    Chima, Rodrick V.; Conners, Timothy R.; Wayman, Thomas R.

    2010-01-01

    A computational analysis of a Gulfstream isentropic external compression supersonic inlet coupled to a Rolls-Royce fan has been completed. The inlet was designed for a small, low sonic boom supersonic vehicle with a design cruise condition of M = 1.6 at 45,000 ft. The inlet design included an annular bypass duct that routed flow subsonically around an engine-mounted gearbox and diverted flow with high shock losses away from the fan tip. Two Reynolds-averaged Navier-Stokes codes were used for the analysis: an axisymmetric code called AVCS for the inlet and a three dimensional (3-D) code called SWIFT for the fan. The codes were coupled at a mixing plane boundary using a separate code for data exchange. The codes were used to determine the performance of the inlet/fan system at the design point and to predict the performance and operability of the system over the flight profile. At the design point the core inlet had a recovery of 96 percent, and the fan operated near its peak efficiency and pressure ratio. A large hub radial distortion generated in the inlet was not eliminated by the fan and could pose a challenge for subsequent booster stages. The system operated stably at all points along the flight profile. Reduced stall margin was seen at low altitude and Mach number where flow separated on the interior lips of the cowl and bypass ducts. The coupled analysis gave consistent solutions at all points on the flight profile that would be difficult or impossible to predict by analysis of isolated components.

  13. Coupled Analysis of an Inlet and Fan for a Quiet Supersonic Aircraft

    Chima, Rodrick V.; Conners, Timothy R.; Wayman, Thomas R.

    2009-01-01

    A computational analysis of a Gulfstream isentropic external compression supersonic inlet coupled to a Rolls-Royce fan was completed. The inlet was designed for a small, low sonic boom supersonic vehicle with a design cruise condition of M = 1.6 at 45,000 feet. The inlet design included an annular bypass duct that routed flow subsonically around an engine-mounted gearbox and diverted flow with high shock losses away from the fan tip. Two Reynolds-averaged Navier-Stokes codes were used for the analysis: an axisymmetric code called AVCS for the inlet and a 3-D code called SWIFT for the fan. The codes were coupled at a mixing plane boundary using a separate code for data exchange. The codes were used to determine the performance of the inlet/fan system at the design point and to predict the performance and operability of the system over the flight profile. At the design point the core inlet had a recovery of 96 percent, and the fan operated near its peak efficiency and pressure ratio. A large hub radial distortion generated in the inlet was not eliminated by the fan and could pose a challenge for subsequent booster stages. The system operated stably at all points along the flight profile. Reduced stall margin was seen at low altitude and Mach number where flow separated on the interior lips of the cowl and bypass ducts. The coupled analysis gave consistent solutions at all points on the flight profile that would be difficult or impossible to predict by analysis of isolated components.

  14. Fixed telephony evolution at CERN

    CERN. Geneva

    2015-01-01

    The heart of CERN’s telephony infrastructure consists of the Alcatel IP-PBX that links CERN’s fixed line phones, Lync softphones and CERN’s GSM subscribers to low-cost local and international telephony services. The PABX infrastructure also supports the emergency “red telephones” in the LHC tunnel and provides vital services for the Fire and Rescue Service and the CERN Control Centre. Although still reliable, the Alcatel hardware is increasingly costly to maintain and looking increasingly outmoded in a market where open source solutions are increasingly dominant. After presenting an overview of the Alcatel PABX and the services it provides, including innovative solutions such as the Closed User Group for our mobile telephony services, we present a possible architecture for a software based system designed to meet tomorrow’s communication needs and describe how the introduction of open-source call routers based on the SIP protocol and Session Border Controllers (SBC) could foster the introduction...

  15. Fixed type incore measuring device

    Oda, Naotaka; Ito, Hitoshi; Maeda, Hiroyuki

    1998-01-01

    The present invention concerns a measuring device using gamma thermometers to be used in a BWR type reactor. An input switch is inserted to the vicinity of a detection signal input portion of a signal cable connecting GT with the detection signal input portion of a fixed type incore measuring device, and a loop resistance measuring means is disposed to the input switch on the side of the GT by way of a measurement switch. Upon measuring loop resistance, the GT measuring circuit is switched from the detection signal input portion to the loop resistance measuring means by a switching operation of the input switch and the measurement switch thereby enabling to confirm the value of the loop resistance. In addition, the lowering of the voltage in the loop resistance is compensated to confirm the accurate measurement values to be used thereby enabling to measure GT detection signals accurately. A diagnosing means for diagnosing the state of GT based on the results of the measurement for the loop resistance is disposed, and the results are reported to an operator. (N.H.)

  16. Augustine Volcano, Cook Inlet, Alaska (January 12, 2006)

    2006-01-01

    Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory (AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO regards that an eruption similar to 1976 and 1986 is the most probable outcome. During January, activity has been episodic, and characterized by emission of steam and ash plumes, rising to altitudes in excess of 9,000 m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER image was acquired at 12:42 AST on January 12, 2006, during an eruptive phase of Augustine. The perspective rendition shows the eruption plume derived from the ASTER image data. ASTER's stereo viewing capability was used to calculate the 3-dimensional topography of the eruption cloud as it was blown to the south by prevailing winds. From a maximum height of 3060 m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft). The perspective view shows the ASTER data draped over the plume top topography, combined with a base image acquired in 2000 by the Landsat satellite, that is itself draped over ground elevation data from the Shuttle Radar Topography Mission. The topographic relief has been increased 1.5 times for this illustration. Comparison of the ASTER plume topography data with ash dispersal models and weather radar data will allow the National Weather Service to validate and improve such models. These models are used to forecast volcanic ash plume trajectories and provide hazard alerts and warnings to aircraft in the Alaska region. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with

  17. Reviving nuclear requires broad technology fix

    Hyman, L.S.

    1991-01-01

    What will it take to revive nuclear power in this country? For a beginning, nuclear plants must be the lowest-cost alternative to providing additional energy supplies; they must be smaller in size and easier to build and license than in the past, and public confidence in nuclear power must be restored. But even this is not enough to attract investors, he says. Regulatory policies, corporate structures, and financial arrangements must change as well. Hyman offers some ideas for changes that would be attractive to investors: place construction work in progress in the rate base, create a pay-as-you-go approach to construction; federal rather than state regulation of power rates; and ownership and construction by a consortium of electrical equipment manufacturers, engineering and construction firms, utilities, and fuel supplies. But even then, Hyman is not optimistic. Fixing nuclear power is possible only if there is a need for the product, the price is right, the profit is adequate, the people want it, the waste is disposed of, and somebody will take the risk of financing its revival

  18. A comprehensive small and pilot-scale fixed-bed reactor approach for testing Fischer–Tropsch catalyst activity and performance on a BTL route

    Piyapong Hunpinyo

    2017-05-01

    Full Text Available Ruthenium (Ru-based catalysts were prepared by the sol–gel technique for biomass-to-liquid (BTL operation and had their performance tested under different conditions. The catalytic study was carried out in two steps using a simple and reliable method. In the first step, the effects of reaction temperatures and inlet H2/CO molar feed ratios obtained from biomass gasification were investigated on the catalyst performance. A set of experimental results obtained in a laboratory fixed bed reactor was described and summarized. Moreover, a simplified Langmuir–Hinshelwood–Hougen–Watson (LHHW kinetic model was proposed with two promising models, where the surface decomposition of carbon monoxide was assumed as the rate determining step (RDS. In the second step, a FT pilot plant was conducted to validate the catalyst performance, especially the conversion efficiency, heat and mass transfer effects, and system controllability. The results indicated that our catalyst performances under mild conditions were not significantly different in many regards from those previously reported for a severe condition, as especially Ru-based catalyst can be performed to vary over a wide range of conditions to yield specific liquid productivity. The results in terms of the hydrocarbon product distribution obtained from the pilot scale operations were similar with that obtained from the related lab scale experiments.

  19. Neural fuzzy modelization of copper removal from water by biosorption in fixed-bed columns using olive stone and pinion shell.

    Calero, M; Iáñez-Rodríguez, I; Pérez, A; Martín-Lara, M A; Blázquez, G

    2018-03-01

    Continuous copper biosorption in fixed-bed column by olive stone and pinion shell was studied. The effect of three operational parameters was analyzed: feed flow rate (2-6 ml/min), inlet copper concentration (40-100 mg/L) and bed-height (4.4-13.4 cm). Artificial Neural-Fuzzy Inference System (ANFIS) was used in order to optimize the percentage of copper removal and the retention capacity in the column. The highest percentage of copper retained was achieved at 2 ml/min, 40 mg/L and 4.4 cm. However, the optimum biosorption capacity was obtained at 6 ml/min, 100 mg/L and 13.4 cm. Finally, breakthrough curves were simulated with mathematical traditional models and ANFIS model. The calculated results obtained with each model were compared with experimental data. The best results were given by ANFIS modelling that predicted copper biosorption with high accuracy. Breakthrough curves surfaces, which enable the visualization of the behavior of the system in different process conditions, were represented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Common fixed points for weakly compatible maps

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    In 1976, Jungck [4] proved a common fixed point theorem for commuting maps generalizing the Banach's fixed point theorem, which states that, 'let (X, d) be a complete metric space. If T satisfies d(Tx,Ty) ≤ kd(x,y) for each x,y ∈ X where 0 ≤ k < 1, then T has a unique fixed point in X'. This theorem has many applications, ...

  1. Infra-red fixed points in supersymmetry

    ¾c /font>, and c stands for the color quadratic Casimir of the field. Fixed points arise when R* ¼ or when R*. /nobr>. ´S-½. µ ´r ·b¿µ. The stability of the solutions may be tested by linearizing the system about the fixed points. For the non-trivial fixed points we need to consider the eigenvalues of the stability matrix whose ...

  2. A life-cycle model for wave-dominated tidal inlets along passive margin coasts of North America

    Seminack, Christopher T.; McBride, Randolph A.

    2018-03-01

    A regional overview of 107 wave-dominated tidal inlets along the U.S. Atlantic coast, U.S. Gulf of Mexico coast, and Canadian Gulf of St. Lawrence coast yielded a generalized wave-dominated tidal inlet life-cycle model that recognized the rotational nature of tidal inlets. Tidal inlets are influenced by concurrently acting processes transpiring over two timescales: short-term, event-driven processes and long-term, evolutionary processes. Wave-dominated tidal inlets are classified into three rotational categories based on net longshore sediment transport direction and rotation direction along the landward (back-barrier) portion of the inlet channel: downdrift channel rotation, updrift channel rotation, or little-to-no channel rotation. Lateral shifting of the flood-tidal delta depocenter in response to available estuarine accommodation space appears to control inlet channel rotation. Flood-tidal delta deposits fill accommodation space locally within the estuary (i.e., creating bathymetric highs), causing the tidal-inlet channel to rotate. External influences, such as fluvial discharge, pre-existing back-barrier channels, and impeding salt marsh will also influence inlet-channel rotation. Storm events may rejuvenate the tidal inlet by scouring sediment within the flood-tidal delta, increasing local accommodation space. Wave-dominated tidal inlets are generally unstable and tend to open, concurrently migrate laterally and rotate, infill, and close. Channel rotation is a primary reason for wave-dominated tidal inlet closure. During rotation, the inlet channel lengthens and hydraulic efficiency decreases, thus causing tidal prism to decrease. Tidal prism, estuarine accommodation space, and sediment supply to the flood-tidal delta are the primary variables responsible for tidal inlet rotation. Stability of wave-dominated tidal inlets is further explained by: stability (S) = tidal prism (Ω) + estuarine accommodation space (V) - volume of annual sediment supply (Mt

  3. Fixed point theorems in spaces and -trees

    Kirk WA

    2004-01-01

    Full Text Available We show that if is a bounded open set in a complete space , and if is nonexpansive, then always has a fixed point if there exists such that for all . It is also shown that if is a geodesically bounded closed convex subset of a complete -tree with , and if is a continuous mapping for which for some and all , then has a fixed point. It is also noted that a geodesically bounded complete -tree has the fixed point property for continuous mappings. These latter results are used to obtain variants of the classical fixed edge theorem in graph theory.

  4. ASSESSING CLIMATE CHANGE IMPACTS ON THE STABILITY OF SMALL TIDAL INLETS: Part 2- DATA RICH ENVIRONMENTS.

    Duong, Trang Minh; Ranasinghe, Roshanka; Thatcher, Marcus; Mahanama, Sarith; Wang, Zheng Bing; Dissanayake, Pushpa Kumara; Hemer, Mark; Luijendijk, Arjen; Bamunawala, Janaka; Roelvink, Dano; Walstra, Dirkjan

    2018-01-01

    Climate change (CC) is likely to affect the thousands of bar-built or barrier estuaries (here referred to as Small tidal inlets - STIs) around the world. Any such CC impacts on the stability of STIs, which governs the dynamics of STIs as well as that of the inlet-adjacent coastline, can result in significant socio-economic consequences due to the heavy human utilisation of these systems and their surrounds. This article demonstrates the application of a process based snap-shot modelling approach, using the coastal morphodynamic model Delft3D , to 3 case study sites representing the 3 main STI types; Permanently open, locationally stable inlets (Type 1), Permanently open, alongshore migrating inlets (Type 2) and Seasonally/Intermittently open, locationally stable inlets (Type 3). The 3 case study sites (Negombo lagoon - Type 1, Kalutara lagoon - Type 2, and Maha Oya river - Type 3) are all located along the southwest coast of Sri Lanka. After successful hydrodynamic and morphodynamic model validation at the 3 case study sites, CC impact assessment are undertaken for a high end greenhouse gas emission scenario. Future CC modified wave and riverflow conditions are derived from a regional scale application of spectral wave models (WaveWatch III and SWAN) and catchment scale applications of a hydrologic model (CLSM) respectively, both of which are forced with IPCC Global Climate Model output dynamically downscaled to ~ 50 km resolution over the study area with the stretched grid Conformal Cubic Atmospheric Model CCAM. Results show that while all 3 case study STIs will experience significant CC driven variations in their level of stability, none of them will change Type by the year 2100. Specifically, the level of stability of the Type 1 inlet will decrease from 'Good' to 'Fair to poor' by 2100, while the level of (locational) stability of the Type 2 inlet will also decrease with a doubling of the annual migration distance. Conversely, the stability of the Type 3 inlet

  5. Factors influencing bonding fixed restorations

    Medić Vesna

    2008-01-01

    Full Text Available INTRODUCTION Crown displacement often occurs because the features of tooth preparations do not counteract the forces directed against restorations. OBJECTIVE The purpose of this study was to evaluate the effect of preparation designs on retention and resistance of fixed restorations. METHOD The study was performed on 64 differently sized stainless steel dies. Also, caps which were used for evaluated retention were made of stainless steel for each die. After cementing the caps on experimental dies, measuring of necessary tensile forces to separate cemented caps from dies was done. Caps, which were made of a silver-palladium alloy with a slope of 60° to the longitudinal axis formed on the occlusal surface, were used for evaluating resistance. A sudden drop in load pressure recorded by the test machine indicated failure for that cap. RESULTS A significant difference was found between the tensile force required to remove the caps from the dies with different length (p<0.05 and different taper (p<0.01. The greatest retentive strengths (2579.2 N and 2989.8 N were noticed in experimental dies with the greatest length and smallest taper. No statistically significant (p>0.05 differences were found between tensile loads for caps cemented on dies with different diameter. Although there was an apparent slight increase in resistance values for caps on dies with smaller tapers, the increase in resistance for those preparation designs was not statistically significant. There was a significant difference among the resistance values for caps on dies with different length (p<0.01 and diameter (p<0.05. CONCLUSION In the light of the results obtained, it could be reasonably concluded that retention and resistance of the restoration is in inverse proportion to convergence angle of the prepared teeth. But, at a constant convergence angle, retention and resistance increase with rising length and diameter.

  6. Numerical modelling to assess maintenance strategy management options for a small tidal inlet

    Shaeri, Saeed; Tomlinson, Rodger; Etemad-Shahidi, Amir; Strauss, Darrell

    2017-03-01

    Small tidal inlets are found to be more sensitive to anthropogenic alteration than their larger counterparts. Such alterations, although typically supported by technical design reports, sometimes require amendments or modification. One of the most suitable tools to conduct the necessary studies in this regard is numerical modelling, since the behaviour of the inlet system in response to proposed remedial actions, can easily be identified. In this paper, various alternative proposals are investigated to determine the most practical and viable option to mitigate the need for ongoing maintenance at a typical small, jettied tidal inlet. The main tool to investigate the alternatives is the hydro-sedimentological modelling of the inlet system, which was performed using the Delft3D software package. The proposed alternative entrance modifications were based upon structural alterations of the inlet system (such as a jetty extension or submerged weir) and non-structural scenarios (such as a change of the time of the dredging campaign or the deposition location of the dredged material). It was concluded that whilst a detailed study is inevitable in order to achieve a comprehensive design plan, based upon the results of this study the construction of a submerged weir at the entrance channel can satisfy the needs of most of the stakeholders, with justifiable costs over a longer period.

  7. Effect of blade sweep on inlet flow in axial compressor cascades

    Hao Chang

    2015-02-01

    Full Text Available This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep. A computational fluid dynamics (CFD package was used to simulate the cascades and obtain the required three-dimensional (3D flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation (CF terms in the momentum equation. A program for data reduction was conducted to obtain a circumferentially averaged flow field. The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.

  8. Portable apparatus for containing and regulating flow of a liquid into a drainage inlet

    Warren, R.E.

    1991-01-01

    This patent describes a method of using an apparatus suitable for containing a mixture of spilled petroleum liquid and water and regulating the flow of water into a storm drain, having a drainage inlet with a recess area extending about a perimeter of the drainage inlet, while minimizing the flow of the petroleum liquid into the storm drain, the apparatus comprising, flange means, defining a central opening therein, for engaging the recess area of the storm drain, the flange means being substantially the same size and shape as a cover of the storm drain so that when the cover is removed from the storm drain, the method comprising the steps of: positioning the apparatus over a storm drain with the flange means being received and supported by the recess area of the storm drain with the central opening overlying the drainage inlet; allowing the mixture of petroleum liquid and water to collect around the apparatus; controlling the position of the movable hollow member, relative to the flange means, to control the flow of water into the drainage inlet, through the sidewall and central openings, while maintaining the petroleum liquid floating on the water and preventing entry of the petroleum liquid into the at least sidewall opening; and collecting the petroleum liquid after a sufficient quantity of water has been allowed to flow into the drainage inlet

  9. Characteristics Air Flow in Room Chamber Test Refrigerator Household Energy Consumption with Inlet Flow Variation

    Susanto, Edy; Idrus Alhamid, M.; Nasruddin; Budihardjo

    2018-03-01

    Room Chamber is the most important in making a good Testing Laboratory. In this study, the 2-D modeling conducted to assess the effect placed the inlet on designing a test chamber room energy consumption of household refrigerators. Where the geometry room chamber is rectangular and approaching the enclosure conditions. Inlet varied over the side parallel to the outlet and compared to the inlet where the bottom is made. The purpose of this study was to determine and define the characteristics of the airflow in the room chamber using CFD simulation. CFD method is used to obtain flow characteristics in detail, in the form of vector flow velocity and temperature distribution inside the chamber room. The result found that the position of the inlet parallel to the outlet causes air flow cannot move freely to the side of the floor, even flow of air moves up toward the outlet. While by making the inlet is below, the air can move freely from the bottom up to the side of the chamber room wall as well as to help uniform flow.

  10. 24 CFR 206.21 - Interest rate.

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Interest rate. 206.21 Section 206... CONVERSION MORTGAGE INSURANCE Eligibility; Endorsement Eligible Mortgages § 206.21 Interest rate. (a) Fixed interest rate. A fixed interest rate is agreed upon by the mortgagor and mortgagee. (b) Adjustable interest...

  11. An experimental study of the effects of bodyside compression on forward swept sidewall compression inlets ingesting a turbulent boundary layer

    Rodi, Patrick E.

    1993-01-01

    Forward swept sidewall compression inlets have been tested in the Mach 4 Blowdown Facility at the NASA Langley Research Center to study the effects of bodyside compression surfaces on inlet performance in the presence of an incoming turbulent boundary layer. The measurements include mass flow capture and mean surface pressure distributions obtained during simulated combustion pressure increases downstream of the inlet. The kerosene-lampblack surface tracer technique has been used to obtain patterns of the local wall shear stress direction. Inlet performance is evaluated using starting and unstarting characteristics, mass capture, mean surface pressure distributions and permissible back pressure limits. The results indicate that inlet performance can be improved with selected bodyside compression surfaces placed between the inlet sidewalls.

  12. Thermal-hydraulic oscillations in a low pressure two-phase natural circulation loop at low powers and high inlet subcoolings

    Wang, S.B.; Wu, J.Y.; Chin Pan; Lin, W.K.

    2004-01-01

    The stability of a natural circulation boiling loop is of great importance and interests for both academic researches and many industrial applications, such as next generation boiling water reactors. The present study investigated the thermal-hydraulic oscillation behavior in a low pressure two-phase natural circulation loop at low powers and high inlet subcoolings. The experiments were conducted at atmospheric pressure with heating power ranging from 4 to 8 kW and inlet subcooling ranging from 27 to 75 deg. C. Significant oscillations in loop mass flow rate, pressure drop in each section, and heated wall and fluid temperatures are present for all the cases studied here. The oscillation is typically quasi-periodic and with flow reversal with magnitudes smaller than forward flows. The magnitude of wall temperature oscillation could be as high as 60 deg. C, which will be of serious concern for practical applications. It is found that the first fundamental oscillation (large magnitude oscillation) frequency increases with increase in heated power and with decrease in inlet subcooling. (author)

  13. PIV measurements of the flow at the inlet of a turbocharger centrifugal compressor with recirculation casing treatment near the inducer

    Gancedo, Matthieu; Gutmark, Ephraim; Guillou, Erwann

    2016-02-01

    Turbocharging reciprocating engines is a viable solution in order to meet the new regulations for emissions and fuel efficiency in part because turbochargers allow to use smaller, more efficient engines (downsizing) while maintaining power. A major challenge is to match the flow range of a dynamic turbomachine (the centrifugal compressor in the turbocharger) with a positive displacement pump (the engine) as the flow range of the latter is typically higher. The operating range of the compressor is thus of prime interest. At low mass flow rate (MFR), the compressor range is limited by the occurrence of surge. To control and improve it, numerous and varied methods have been used. Yet, an automotive application requires that the solution remains relatively simple and preferably passive. A common feature that has been demonstrated to improve the surge line is the use of flow recirculation in the inducer region through a circumferential bleed slot around the shroud, also called "ported shroud", similar to what has been developed for axial compressors in the past. The compressor studied here features such a device. In order to better understand the effect of the recirculation slot on the compressor functioning, flow measurements were performed at the inlet using particle image velocimetry and the results were correlated with pressure measurements nearby. Measurements were taken on a compressor with and without recirculation and across the full range of normal operation and during surge using a phase-locking method to obtain average flow fields throughout the entire surge cycle. When the recirculation is blocked, it was found that strong backflow develops at low MFR perturbing the incoming flow and inducing significant preswirl. The slot eliminated most of the backflow in front of the inducer making the compressor operation more stable. The measurements performed during surge showed strong backflow occurring periodically during the outlet pressure drop and when the

  14. Electrochemical treatment of water containing Microcystis aeruginosa in a fixed bed reactor with three-dimensional conductive diamond anodes.

    Mascia, Michele; Monasterio, Sara; Vacca, Annalisa; Palmas, Simonetta

    2016-12-05

    An electrochemical treatment was investigated to remove Microcystis aeruginosa from water. A fixed bed reactor in flow was tested, which was equipped with electrodes constituted by stacks of grids electrically connected in parallel, with the electric field parallel to the fluid flow. Conductive diamond were used as anodes, platinised Ti as cathode. Electrolyses were performed in continuous and in batch recirculated mode with flow rates corresponding to Re from 10 to 160, current densities in the range 10-60Am(-2) and Cl(-) concentrations up to 600gm(-3). The absorbance of chlorophyll-a pigment and the concentration of products and by-products of electrolysis were measured. In continuous experiments without algae in the inlet stream, total oxidants concentrations as equivalent Cl2, of about 0.7gCl2m(-3) were measured; the maximum values were obtained at Re=10 and i=25Am(-2), with values strongly dependent on the concentration of Cl(-). The highest algae inactivation was obtained under the operative conditions of maximum generation of oxidants; in the presence of microalgae the oxidants concentrations were generally below the detection limit. Results indicated that most of the bulk oxidants electrogenerated is constituted by active chlorine. The prevailing mechanism of M. aeruginosa inactivation is the disinfection by bulk oxidants. The experimental data were quantitatively interpreted through a simple plug flow model, in which the axial dispersion accounts for the non-ideal flow behaviour of the system; the model was successfully used to simulate the performances of the reactor in the single-stack configuration used for the experiments and in multi-stack configurations. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Mathematical modelling and optimization of hydrogen continuous production in a fixed bed bioreactor

    Palazzi, E.; Perego, P.; Fabiano, B. [University of Genoa, Genova (Italy). Chemical and Process Engineering Department ' G.B. Bonino'

    2002-09-01

    The purpose of this paper is to investigate, both theoretically and experimentally, hydrogen production from agro-industrial by-products using a continuous bioreactor packed with a mixture of spongy and glass beads and inoculated with Enterobacter aerogenes. Replicated series of experimental runs were performed to study the effects of residence time on hydrogen evolution rate and to characterize the critical conditions for the wash out, as a function of the inlet glucose concentration and of the fluid superficial velocity. A further series of experimental runs was focused on the effects of both residence time and inlet glucose concentration over hydrogen productivity. A kinetic model of the process was developed and showed good agreement with experimental data, thus representing a potential tool to design a large-scale fermenter. In fact, the model was applied to the optimal design of a bioreactor suitable of feeding a phosphoric acid fuel cell of a target power. (author)

  16. Effect of inlet conditions on the performance of a palladium membrane reactor

    Birdsell, S.A.; Willms, R.S.; Arzu, P.; Costello, A.

    1997-10-01

    Palladium membrane reactors (PMR) will be used to remove tritium and other hydrogen isotopes from impurities, such as tritiated methane and tritiated water, in the exhaust of the International Thermonuclear Experimental Reactor. In addition to fusion-fuel processing, the PMR system can be used to recover tritium from tritiated waste water. This paper investigates the effect of inlet conditions on the performance of a PMR. A set of experiments were run to determine, independently, the effect of inlet compositions and residence time on performance. Also, the experiments were designed to determine if the injected form of hydrogen (CH 4 or H 2 O) effects performance. Results show that the PMR operates at optimal hydrogen recovery with a broad range of inlet compositions and performance is shown to increase with increased residence time. PMR performance is shown to be independent of whether hydrogen is injected in the form of CH 4 or H 2 O

  17. Improving the performance of a compression ignition engine by directing flow of inlet air

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  18. Aero-Thermo-Structural Analysis of Inlet for Rocket Based Combined Cycle Engines

    Shivakumar, K. N.; Challa, Preeti; Sree, Dave; Reddy, Dhanireddy R. (Technical Monitor)

    2000-01-01

    NASA has been developing advanced space transportation concepts and technologies to make access to space less costly. One such concept is the reusable vehicles with short turn-around times. The NASA Glenn Research Center's concept vehicle is the Trailblazer powered by a rocket-based combined cycle (RBCC) engine. Inlet is one of the most important components of the RBCC engine. This paper presents fluid flow, thermal, and structural analysis of the inlet for Mach 6 free stream velocity for fully supersonic and supercritical with backpressure conditions. The results concluded that the fully supersonic condition was the most severe case and the largest stresses occur in the ceramic matrix composite layer of the inlet cowl. The maximum tensile and the compressive stresses were at least 3.8 and 3.4, respectively, times less than the associated material strength.

  19. Second order tidally induced flow in the inlet of a coastal lagoon

    Eguiluz, Ana; Wong, Kuo-Chuin

    2005-08-01

    Current meter data obtained in Indian River Inlet and Indian River Bay, Delaware are analyzed to compute second order low-frequency tidal flow and tidally induced mean flow in the system. Results from least-squares harmonic analysis show that nonlinearly induced M4 currents in the inlet and bay occur at order 10 -1 of the M2 amplitudes, indicating weak nonlinearity in the system. Tidally rectified mean flow computed from Mm and Msf is ˜3 cm s -1, which is of the same order of magnitude as the observed mean current. The estimated low-frequency tidal flow and the tidally induced mean flow agree well with scalings computed for the inlet and with results found by Münchow et al. [Münchow, A., Masse, A.K., Garvine, R.W., 1992. Astronomical and nonlinear tidal currents in a coupled estuary shelf system. Continental Shelf Research 12, 471-498] in Delaware Bay.

  20. A CFD Study on Inlet Plenum Flow Field of Pebble Bed Reactor

    Kim, Min Hwan; Lee, Won Jae; Chang, Jong Hwa

    2005-01-01

    High temperature gas cooled reactor, largely divided into two types of PBR (Pebble Bed Reactor) and PMR (Prismatic Modular Reactor), has becomes great interest of researchers in connection with the hydrogen production. KAERI has started a project to develop the gas cooled reactor for the hydrogen production and has been doing in-depth study for selecting the reactor type between PBR and PMR. As a part of the study, PBMR (Pebble Bed Modular Reactor) was selected as a reference PBR reactor for the CFD analysis and the flow field of its inlet plenum was simulated with computational fluid dynamics program CFX5. Due to asymmetrical arrangement of pipes to the inlet plenum, non-uniform flow distribution has been expected to occur, giving rise to non-uniform power distribution at the core. Flow fields of different arrangement of inlet pipes were also investigated, as one of measures to reduce the non-uniformity

  1. Quantification of tidal inlet morphodynamics using high-resolution MBES and LiDAR

    Ernstsen, Verner Brandbyge; Lefebvre, Alice; Fraccascia, Serena

    -bathymetric surveys using high-resolution red and green Light Detection And Ranging (LiDAR). Detailed digital elevation models with a grid cell size of 1 m x 1 m were generated and analysed geomorphometrically. The analyses reveal a main ebb-directed net sand transport in the main channel; however, due...... to the geometry of the main channel, displaying a confluent meander bend, confined areas in the main channel are characterised by an opposite-directed net sand transport. In the inter-tidal areas the main net sand transport is flood-directed. However, also here the analyses reveal the existence of oblique second...... is transported from the inlet channel to the intertidal flat. Therefore, in addition to the typical main sand transport directions with net export in the inlet channel and net import over the adjacent inter-tidal flats, these investigations suggest an exchange and possible recirculation of sand between the inlet...

  2. The impact of inlet angle and outlet angle of guide vane on pump in reversal based hydraulic turbine performance

    Shi, F X; Yang, J H; Wang, X H; Zhang, R H; Li, C E

    2012-01-01

    In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.

  3. Analysis of Post-LOCA Core Inlet Blockage to Evaluate In-vessel Downstream Effect in APR1400

    Bang, Young Seok [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    The method was developed to have a conservatism to cover the uncertainty of analysis and the acceptance is judged by the representative bounding estimation. However, the important safety parameters such as the available driving head need to be confirmed by the plant specific calculation. Also an interaction between the debris induced head loss and the core flow rate needs to be explained because the head loss induced by debris in actual condition may reduce the core inflow rate faster. To confirm the safety parameters, in this study, thermal-hydraulic response considering the core inlet blockage (CIB) by debris during LTCC process following a double-ended guillotine break of cold leg (CLB), one of hot leg (HLB) and one of intermediate leg (ILB) of the APR1400 were calculated, respectively. MARS-KS 1.3 code has been used. The CIB has been modeled by the closure of valves to the core in exponential manner with time to observe the behavior near the complete blockage. To understand the effect of core inlet blockage (CIB) during a long term core cooling (LTCC) phase following a loss-of-coolant accident (LOCA) in the light of in-vessel downstream effect (IDE) of Generic Safety Issue (GSI) 191, double-ended guillotine break of hot leg (HLB), one of cold leg (CLB) and one of intermediate leg (ILB) were calculated, respectively. And the important safety parameters such as the available driving head and the head loss due to debris were calculated using MARS-KS code and discussed in comparison with the WCAP method. As a result, a little delayed heatup behavior of the fuel cladding was found for all the cases, which due to the redistribution of flow within the core after blockage.

  4. Analysis of Post-LOCA Core Inlet Blockage to Evaluate In-vessel Downstream Effect in APR1400

    Bang, Young Seok

    2015-01-01

    The method was developed to have a conservatism to cover the uncertainty of analysis and the acceptance is judged by the representative bounding estimation. However, the important safety parameters such as the available driving head need to be confirmed by the plant specific calculation. Also an interaction between the debris induced head loss and the core flow rate needs to be explained because the head loss induced by debris in actual condition may reduce the core inflow rate faster. To confirm the safety parameters, in this study, thermal-hydraulic response considering the core inlet blockage (CIB) by debris during LTCC process following a double-ended guillotine break of cold leg (CLB), one of hot leg (HLB) and one of intermediate leg (ILB) of the APR1400 were calculated, respectively. MARS-KS 1.3 code has been used. The CIB has been modeled by the closure of valves to the core in exponential manner with time to observe the behavior near the complete blockage. To understand the effect of core inlet blockage (CIB) during a long term core cooling (LTCC) phase following a loss-of-coolant accident (LOCA) in the light of in-vessel downstream effect (IDE) of Generic Safety Issue (GSI) 191, double-ended guillotine break of hot leg (HLB), one of cold leg (CLB) and one of intermediate leg (ILB) were calculated, respectively. And the important safety parameters such as the available driving head and the head loss due to debris were calculated using MARS-KS code and discussed in comparison with the WCAP method. As a result, a little delayed heatup behavior of the fuel cladding was found for all the cases, which due to the redistribution of flow within the core after blockage

  5. Magnetic Fixed Points and Emergent Supersymmetry

    Antipin, Oleg; Mojaza, Matin; Pica, Claudio

    2013-01-01

    We establish in perturbation theory the existence of fixed points along the renormalization group flow for QCD with an adjoint Weyl fermion and scalar matter reminiscent of magnetic duals of QCD [1-3]. We classify the fixed points by analyzing their basin of attraction. We discover that among...

  6. Fixed Wireless may be a temporary answer

    Possible to enhance throughput by 4 with respect to Mobile Wireless. And get 8 to 10 bps / Hz / cell; Examples: BB corDECT: today provides 256/512kbps to each connection in fixed environment. Ideal for small town / rural Broadband. Fixed 802.16d/e does the same in but at much higher price-points.

  7. Metallic and antiferromagnetic fixed points from gravity

    Paul, Chandrima

    2018-06-01

    We consider SU(2) × U(1) gauge theory coupled to matter field in adjoints and study RG group flow. We constructed Callan-Symanzik equation and subsequent β functions and study the fixed points. We find there are two fixed points, showing metallic and antiferromagnetic behavior. We have shown that metallic phase develops an instability if certain parametric conditions are satisfied.

  8. Gaining Insight into an Organization's Fixed Assets.

    Hardy, Elisabet

    2003-01-01

    Discusses issues related to school district implementation of June 2001 Government Accounting Standards Board (GASB) Statement 34 designed to change how schools report fixed assets. Includes planning for GASB implementation, conducting fixed-asset inventories, and making time for GASB reporting. (PKP)

  9. 78 FR 20705 - Fixed Income Roundtable

    2013-04-05

    ... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-69275; File No. 4-660] Fixed Income Roundtable... of fixed income markets. The roundtable will focus on the municipal securities, corporate bonds, and asset-backed securities markets. The roundtable discussion will be held in the multi-purpose room of the...

  10. Gauge fixing problem in the conformal QED

    Ichinose, Shoichi

    1986-01-01

    The gauge fixing problem in the conformal (spinor and scalar) QED is examined. For the analysis, we generalize Dirac's manifestly conformal-covariant formalism. It is shown that the (vector and matter) fields must obey a certain mixed (conformal and gauge) type of transformation law in order to fix the local gauge symmetry preserving the conformal invariance in the Lagrangian. (orig.)

  11. Fixed export cost heterogeneity, trade and welfare

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    -country intra-industry trade model where firms are of two different marginal costs types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral...

  12. Impact of fixed-mobile convergence

    Pachnicke, Stephan; Andrus, Bogdan-Mihai; Autenrieth, Achim

    2016-01-01

    Fixed-Mobile Convergence (FMC) is a very trendy concept as it promises integration of the previously separated fixed access network and the mobile network. From this novel approach telecommunication operators expect significant cost savings and performance improvements. FMC can be separated...

  13. Economical analysis of the spray drying process by pre-dehumidification of the inlet air

    Madeira, A.N.; Camargo, J.R. [University of Taubate (UNITAU), SP (Brazil). Mechanical Engineering Dept.

    2009-07-01

    Spray drying is a dehumidification process by atomization in a closed chamber that aims to remove moisture of a product by heat and mass transfer from the product's contained water to the air that, in this process is previously heated. This paper presents a case study for an industry that produces food ingredients. The current process applied in the product to heat the air can uses one of these two systems: a direct heating process that burns liquid petroleum gas in contact with the inlet air or indirect heating that uses a heat exchanger which heat the air. This heating system consumes 90% of the total process energy. However, this inlet air can reach the dehumidifier with high moisture from the atmosphere condition requesting, in this case, more energy consumption according to the year's seasons. This paper promotes a utilization study of the current process through the installation of a pre-dehumidification device of the inlet air and shows a study to three different dehumidification systems that means by refrigeration, adsorption and actual comparing their performance in an energetic and economical point of view. The goals of this study are to analyze the capacity of moisture removing of each removing device, the influence of moisture variation of the inlet air in the process as well as the economic impact of each device in the global system. It concludes that the utilization of dehumidification devices can eliminate the heating system reducing this way the energy consumption. Moreover it promotes the increasing of moisture gradient between the inlet air and the product optimizing the drying process and increasing the global energy efficiency in the global system. Choosing the most appropriate system for the pre-dehumidification device depends on the desired initial and final moisture content of the product, but applying pre-dehumidifiers at the inlet air promotes an energetic optimization in the spray drying process. (author)

  14. Combined Cycle Engine Large-Scale Inlet for Mode Transition Experiments: System Identification Rack Hardware Design

    Thomas, Randy; Stueber, Thomas J.

    2013-01-01

    The System Identification (SysID) Rack is a real-time hardware-in-the-loop data acquisition (DAQ) and control instrument rack that was designed and built to support inlet testing in the NASA Glenn Research Center 10- by 10-Foot Supersonic Wind Tunnel. This instrument rack is used to support experiments on the Combined-Cycle Engine Large-Scale Inlet for Mode Transition Experiment (CCE? LIMX). The CCE?LIMX is a testbed for an integrated dual flow-path inlet configuration with the two flow paths in an over-and-under arrangement such that the high-speed flow path is located below the lowspeed flow path. The CCE?LIMX includes multiple actuators that are designed to redirect airflow from one flow path to the other; this action is referred to as "inlet mode transition." Multiple phases of experiments have been planned to support research that investigates inlet mode transition: inlet characterization (Phase-1) and system identification (Phase-2). The SysID Rack hardware design met the following requirements to support Phase-1 and Phase-2 experiments: safely and effectively move multiple actuators individually or synchronously; sample and save effector control and position sensor feedback signals; automate control of actuator positioning based on a mode transition schedule; sample and save pressure sensor signals; and perform DAQ and control processes operating at 2.5 KHz. This document describes the hardware components used to build the SysID Rack including their function, specifications, and system interface. Furthermore, provided in this document are a SysID Rack effectors signal list (signal flow); system identification experiment setup; illustrations indicating a typical SysID Rack experiment; and a SysID Rack performance overview for Phase-1 and Phase-2 experiments. The SysID Rack described in this document was a useful tool to meet the project objectives.

  15. A numerical analysis on the effect of inlet parameters for condensation induced water hammer

    Datta, Priyankan [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Chakravarty, Aranyak [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); School of Nuclear Studies & Application, Jadavpur University, Kolkata (India); Ghosh, Koushik, E-mail: kghosh@mech.jdvu.ac.in [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Mukhopadhyay, Achintya; Sen, Swarnendu [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Dutta, Anu; Goyal, Priyanshu [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai (India)

    2016-08-01

    Highlights: • Condensation induced water hammer phenomenon is analysed with RELAP5/Mod 3.4. • Effect of various inlet conditions on the occurrence of CIWH are investigated. • Pressure peak amplitude and location has strong dependency on water subcooling. • Superheated steam does not have significant impact on pressure amplitude. • Presence of dry saturated steam is the necessary condition for CIWH. - Abstract: Direct contact condensation (DCC) is almost an inevitable phenomenon during accidental condition for all LWRs. Rapid condensation caused by the direct contact of steam and subcooled water can lead to condensation induced water hammer (CIWH). The present work explores the underlying physics of CIWH phenomenon in a horizontal pipe under different inlet conditions such as inlet water temperature, pressure difference between steam and water section, steam superheating, steam quality and duration of valve opening using RELAP5/Mod 3.4. This work emphasises on the prediction of pressure peak magnitude in conjunction with its location of occurrence under different parametric conditions. The stratified to slug flow transition is presented in terms of the ‘flow regime map’ which is identified as the primary cause for pressure wave generation. The strongest pressure wave amplitude due to CIWH is found to be 116.6 bar for ΔP = 10 bar. Observation reveals that peak pressure location shifts towards the subcooled water injection point for higher inlet water temperature. For the lowest inlet water temperature (T{sub in} = 20 °C), the peak pressure is found at a distance of 47.5 cm away from the water inlet whereas, for the high water temperature (T{sub in} = 120 °C), peak pressure is observed at 6.25 cm away from the injection point. It is also observed that the duration of valve opening significantly affects the location of peak pressure occurrence. This study also reveals that the presence of superheated or wet steam could possibly avoid the occurrence of

  16. Global gauge fixing in lattice gauge theories

    Fachin, S.; Parrinello, C. (Physics Department, New York University, 4 Washington Place, New York, New York (USA))

    1991-10-15

    We propose a covariant, nonperturbative gauge-fixing procedure for lattice gauge theories that avoids the problem of Gribov copies. This is closely related to a recent proposal for a gauge fixing in the continuum that we review. The lattice gauge-fixed model allows both analytical and numerical investigations: on the analytical side, explicit nonperturbative calculations of gauge-dependent quantities can be easily performed in the framework of a generalized strong-coupling expansion, while on the numerical side a stochastic gauge-fixing algorithm is very naturally associated with the scheme. In both applications one can study the gauge dependence of the results, since the model actually provides a smooth'' family of gauge-fixing conditions.

  17. Algorithms for solving common fixed point problems

    Zaslavski, Alexander J

    2018-01-01

    This book details approximate solutions to common fixed point problems and convex feasibility problems in the presence of perturbations. Convex feasibility problems search for a common point of a finite collection of subsets in a Hilbert space; common fixed point problems pursue a common fixed point of a finite collection of self-mappings in a Hilbert space. A variety of algorithms are considered in this book for solving both types of problems, the study of which has fueled a rapidly growing area of research. This monograph is timely and highlights the numerous applications to engineering, computed tomography, and radiation therapy planning. Totaling eight chapters, this book begins with an introduction to foundational material and moves on to examine iterative methods in metric spaces. The dynamic string-averaging methods for common fixed point problems in normed space are analyzed in Chapter 3. Dynamic string methods, for common fixed point problems in a metric space are introduced and discussed in Chapter ...

  18. Effect of temperature change at inlet of engine on the corrected performance of turbofan engine

    Kozu, Masao; Yajima, Satoshi [Defence Agency, Tokyo, JapanIshikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1989-06-10

    Theoretical consideration on the effect of inlet temperature change of engine on the engine performance was conducted, and soundness of the result was appreciated by applying it to the experimental result of turbofan engine. As the theoretical consideration, premises of Buckingham's fundamental theorem was corrected by Reynolds Number and by the consideration on the effect of inlet temperature on gas constant and specific heat ratio. By using the result, correction factors were calculated from the experimental result of an actual turbo-fan engine. The correction factors were applied to the other engine test result and confirmed satisfactory soundness. 4 refs., 11 figs.

  19. Sodium steam generator within which are inlet and outlet ducts with pipe bundles in vessel

    1980-01-01

    The sodium steam generator with internal flow ducts for inlet and outlet to a vessel are provided as pipe bundles in the form of helically wound concentric layers terminating in inlet and outlet connections with chambers, characterised in that within the vessel, the pipe pieces which are connected to the pipe windings with the said vessel are arranged in substantially radially aligned rows so that each row measured in the circumferential direction at least on one side is at a spacing from the following row sufficiently large that between the rows or groups of rows an open sector is provided. (G.C.)

  20. Experimental Investigation of a Hypersonic Inlet with Variable Sidewall for Flow Control

    Rolim, T. C.; Lu, F. K.

    The main function of a scramjet inlet is to decelerate and compress the air for subsequent reaction with the fuel inside the combustor and, of course, contribute toward meeting the thrust requirement for the entire mission by providing adequate mass flow. It is desirable that the inlet be lightweight and that its geometry be capable of producing a uniform flow in an appropriate state to permit efficient mixing and subsequent combustion. Engine cycle analysis indicates that high contraction ratios CR are desirable for achieving high overall engine efficiency.

  1. Numerical modeling of straw combustion in a fixed bed

    Zhou, Haosheng; Jensen, Anker; Glarborg, Peter

    2005-01-01

    . The straw combustion processes include moisture evaporation, straw pyrolysis, gas combustion, and char combustion. The model provides detailed information of the structure of the ignition flame front. Simulated gas species concentrations at the bed surface, ignition flame front rate, and bed temperature......Straw is being used as main renewable energy source in grate boilers in Denmark. For optimizing operating conditions and design parameters, a one-dimensional unsteady heterogeneous mathematical model has been developed and experiments have been carried out for straw combustion in a fixed bed...... are in good agreement with measurements at different operating conditions such as primary air-flow rate, pre-heating of the primary air, oxygen concentration, moisture content in straw, and bulk density of the straw in the fixed bed. A parametric study indicates that the effective heat conductivity, straw...

  2. Electrochemical treatment of water containing Microcystis aeruginosa in a fixed bed reactor with three-dimensional conductive diamond anodes

    Mascia, Michele; Monasterio, Sara; Vacca, Annalisa; Palmas, Simonetta

    2016-01-01

    Highlights: • Inactivation of M. aeruginosa was achieved by electrolysis with BDD anodes. • A fixed bed reactor with 3-D electrodes was tested in batch and continuous mode. • The kinetics of the process was determined from batch experiments. • A mathematical model of the process was implemented and validated. • The model was used to predict the system behaviour under different conditions. - Abstract: An electrochemical treatment was investigated to remove Microcystis aeruginosa from water. A fixed bed reactor in flow was tested, which was equipped with electrodes constituted by stacks of grids electrically connected in parallel, with the electric field parallel to the fluid flow. Conductive diamond were used as anodes, platinised Ti as cathode. Electrolyses were performed in continuous and in batch recirculated mode with flow rates corresponding to Re from 10 to 160, current densities in the range 10–60 A m −2 and Cl − concentrations up to 600 g m −3 . The absorbance of chlorophyll-a pigment and the concentration of products and by-products of electrolysis were measured. In continuous experiments without algae in the inlet stream, total oxidants concentrations as equivalent Cl 2 , of about 0.7 g Cl 2 m −3 were measured; the maximum values were obtained at Re = 10 and i = 25 A m −2 , with values strongly dependent on the concentration of Cl − . The highest algae inactivation was obtained under the operative conditions of maximum generation of oxidants; in the presence of microalgae the oxidants concentrations were generally below the detection limit. Results indicated that most of the bulk oxidants electrogenerated is constituted by active chlorine. The prevailing mechanism of M. aeruginosa inactivation is the disinfection by bulk oxidants. The experimental data were quantitatively interpreted through a simple plug flow model, in which the axial dispersion accounts for the non-ideal flow behaviour of the system; the model was successfully

  3. Electrochemical treatment of water containing Microcystis aeruginosa in a fixed bed reactor with three-dimensional conductive diamond anodes

    Mascia, Michele, E-mail: michele.mascia@unica.it; Monasterio, Sara; Vacca, Annalisa; Palmas, Simonetta

    2016-12-05

    Highlights: • Inactivation of M. aeruginosa was achieved by electrolysis with BDD anodes. • A fixed bed reactor with 3-D electrodes was tested in batch and continuous mode. • The kinetics of the process was determined from batch experiments. • A mathematical model of the process was implemented and validated. • The model was used to predict the system behaviour under different conditions. - Abstract: An electrochemical treatment was investigated to remove Microcystis aeruginosa from water. A fixed bed reactor in flow was tested, which was equipped with electrodes constituted by stacks of grids electrically connected in parallel, with the electric field parallel to the fluid flow. Conductive diamond were used as anodes, platinised Ti as cathode. Electrolyses were performed in continuous and in batch recirculated mode with flow rates corresponding to Re from 10 to 160, current densities in the range 10–60 A m{sup −2} and Cl{sup −} concentrations up to 600 g m{sup −3}. The absorbance of chlorophyll-a pigment and the concentration of products and by-products of electrolysis were measured. In continuous experiments without algae in the inlet stream, total oxidants concentrations as equivalent Cl{sub 2}, of about 0.7 g Cl{sub 2} m{sup −3} were measured; the maximum values were obtained at Re = 10 and i = 25 A m{sup −2}, with values strongly dependent on the concentration of Cl{sup −}. The highest algae inactivation was obtained under the operative conditions of maximum generation of oxidants; in the presence of microalgae the oxidants concentrations were generally below the detection limit. Results indicated that most of the bulk oxidants electrogenerated is constituted by active chlorine. The prevailing mechanism of M. aeruginosa inactivation is the disinfection by bulk oxidants. The experimental data were quantitatively interpreted through a simple plug flow model, in which the axial dispersion accounts for the non-ideal flow behaviour of the

  4. On generalized fixed sequence procedures for controlling the FWER.

    Qiu, Zhiying; Guo, Wenge; Lynch, Gavin

    2015-12-30

    Testing a sequence of pre-ordered hypotheses to decide which of these can be rejected or accepted while controlling the familywise error rate (FWER) is of importance in many scientific studies such as clinical trials. In this paper, we first introduce a generalized fixed sequence procedure whose critical values are defined by using a function of the numbers of rejections and acceptances, and which allows follow-up hypotheses to be tested even if some earlier hypotheses are not rejected. We then construct the least favorable configuration for this generalized fixed sequence procedure and present a sufficient condition for the FWER control under arbitrary dependence. Based on the condition, we develop three new generalized fixed sequence procedures controlling the FWER under arbitrary dependence. We also prove that each generalized fixed sequence procedure can be described as a specific closed testing procedure. Through simulation studies and a clinical trial example, we compare the power performance of these proposed procedures with those of the existing FWER controlling procedures. Finally, when the pairwise joint distributions of the true null p-values are known, we further improve these procedures by incorporating pairwise correlation information while maintaining the control of the FWER. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Use of fixed income products within a company's portfolio

    Vasile DEDU

    2012-10-01

    Full Text Available Financial instruments have been developed over time from bonds, with a simple structure of cash flows, to yielding instruments that have a complex structure, attracting a much broader range of investors and permitting issuers of bonds to allow reduce the costs of fund raising. To construct investment strategies to control interest rate risk and grow revenues, investors must understand the forcesthat controls the bond market but also the tendencies.The main objective of this paper is to show how they apply to an investment strategy and asset allocation tools available. Fixed income products occupy a large share in total assets, so we want to highlight how to use fixed income products in order to optimize the portfolio of companies. Working hypothesis we chose looks at how the value of financial assets is influenced by macroeconomic factors and market price developments. Investment banks, in particular, put great emphasis on fixed income products and their use by customers. Thus traditional banking and financial products together with fixed income products enables companies to finance current needs, to finance development and to diversify the asset allocation tools.

  6. Fixing noble gas in zeolites

    Rocha Dorea, A.L. da.

    1980-09-01

    In order to increase safety during the long-term storage of Kr-85 it has been proposed to encaosulate this gas in zeolite 5A. Due to the decay heat of Kr-85 it is expected, however, that the inorganic matrix will be at an increased temperature over several decades. Below 600 0 C only very small Kr-desorption rates are observed when a linear temperature gradient is applied to a loaded 5A zeolite sample. If heating is interrupted and the temperature kept konstant at a certain value (>600 0 C), it is observed that the desorption rate either decreased below the detection limit or stayed constant at some measurable value. The overall activation energy in the temperature range 570 0 C-745 0 C is found to be 250 kJ/mol. At temperature above 790 0 C the total encapsulated gas is rapidly liberated. No significant leakage was apparent from zeolite 5A samples containing between 19 and 57 cm 3 STP Kr/g kept at 200 0 C for up to 2500 h and 400 0 C for up to 3500 h. From these studies it is found that type 5A zeolites are particularly suitable as a matrix for the inmobilization of Kr-85. (Author) [pt

  7. About Applications of the Fixed Point Theory

    Bucur Amelia

    2017-06-01

    Full Text Available The fixed point theory is essential to various theoretical and applied fields, such as variational and linear inequalities, the approximation theory, nonlinear analysis, integral and differential equations and inclusions, the dynamic systems theory, mathematics of fractals, mathematical economics (game theory, equilibrium problems, and optimisation problems and mathematical modelling. This paper presents a few benchmarks regarding the applications of the fixed point theory. This paper also debates if the results of the fixed point theory can be applied to the mathematical modelling of quality.

  8. The 1994 Fermilab Fixed Target Program

    Conrad, J.

    1994-11-01

    This paper highlights the results of the Fermilab Fixed Target Program that were announced between October, 1993 and October, 1994. These results are drawn from 18 experiments that took data in the 1985, 1987 and 1990/91 fixed target running periods. For this discussion, the Fermilab Fixed Target Program is divided into 5 major topics: hadron structure, precision electroweak measurements, heavy quark production, polarization and magnetic moments, and searches for new phenomena. However, it should be noted that most experiments span several subtopics. Also, measurements within each subtopic often affect the results in other subtopics. For example, parton distributions from hadron structure measurements are used in the studies of heavy quark production

  9. Hybrid fixed point in CAT(0 spaces

    Hemant Kumar Pathak

    2018-02-01

    Full Text Available In this paper, we introduce an ultrapower approach to prove fixed point theorems for $H^{+}$-nonexpansive multi-valued mappings in the setting of CAT(0 spaces and prove several hybrid fixed point results in CAT(0 spaces for families of single-valued nonexpansive or quasinonexpansive mappings and multi-valued upper semicontinuous, almost lower semicontinuous or $H^{+}$-nonexpansive mappings which are weakly commuting. We also establish a result about structure of the set of fixed points of $H^{+}$-quasinonexpansive mapping on a CAT(0 space.

  10. Residual water transport in the Marsdiep tidal inlet inferred from observations and a numerical model

    Sassi, M.G.; Gerkema, T.; Duran-Matute, M.; Nauw, J.J.

    2016-01-01

    At tidal inlets, large amounts of water are exchanged with the adjacent sea during the tidal cycle.The residual flows, the net effect of ebb and flood, are generally small compared with the gross flux;they vary in magnitude and sign from one tidal period to the other; and their long-term mean

  11. Residual water transport in the Marsdiep tidal inlet inferred from observations and a numerical model

    Sassi, M.G.; Gerkema, T.; Duran-Matute, M.; Nauw, J.J.

    At tidal inlets, large amounts of water are exchanged with the adjacent sea during the tidal cycle. The residual flows, the net effect of ebb and flood, are generally small compared with the gross flux; they vary in magnitude and sign from one tidal period to the other; and their long-term mean

  12. Evaluation of inlet sampling integrity on NSF/NCAR airborne platforms

    Campos, T. L.; Stith, J. L.; Stephens, B. B.; Romashkin, P.

    2017-12-01

    An inlet test project was conducted during IDEAS-IV-GV (2013), to evaluate the sampling integrity of two inlet designs. Use of a single CO2 sensor provided a high precision detector and a large difference in the mean cabin and external concentrations (500-700 ppmv in the cabin). The original HIAPER Modular InLet (HIMIL) is comprised of a tapered flow straightening flow through `cigar' mounted to a strut. The cigar center sampling line sits 12" from the fuselage skin. An o-ring seals the feedthrough plate coupling sampling lines from the strut into the cigar. However, there is no seal to prevent air inside the strut from seeping out around the cigar body. A pressure-equalizing drain hole in the strut access panel; it was positioned at an approximate distance of 4" from the fuselage to ensure that air from any source that drained out of the strut was confined to a low release point. A second aft-facing inlet design was also evaluated. The sampling center line was moved farther from the fuselage at a height of 16". A similar approach was also applied to sampling locations on the C-130 in 2015. The results of these tests and recommendations for best practices will be presented.

  13. Automatic efficiency optimization of an axial compressor with adjustable inlet guide vanes

    Li, Jichao; Lin, Feng; Nie, Chaoqun; Chen, Jingyi

    2012-04-01

    The inlet attack angle of rotor blade reasonably can be adjusted with the change of the stagger angle of inlet guide vane (IGV); so the efficiency of each condition will be affected. For the purpose to improve the efficiency, the DSP (Digital Signal Processor) controller is designed to adjust the stagger angle of IGV automatically in order to optimize the efficiency at any operating condition. The A/D signal collection includes inlet static pressure, outlet static pressure, outlet total pressure, rotor speed and torque signal, the efficiency can be calculated in the DSP, and the angle signal for the stepping motor which control the IGV will be sent out from the D/A. Experimental investigations are performed in a three-stage, low-speed axial compressor with variable inlet guide vanes. It is demonstrated that the DSP designed can well adjust the stagger angle of IGV online, the efficiency under different conditions can be optimized. This establishment of DSP online adjustment scheme may provide a practical solution for improving performance of multi-stage axial flow compressor when its operating condition is varied.

  14. 77 FR 38236 - Special Local Regulation, Underwater Music Festival, Carr Inlet, Cutts Island, WA

    2012-06-27

    ...-AA08 Special Local Regulation, Underwater Music Festival, Carr Inlet, Cutts Island, WA AGENCY: Coast... ensure the safety of the maritime public during the Underwater Music Festival and would do so by... Music Festival is an event which includes musical performances from a barge. Spectators approach the...

  15. Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets

    Gryczka, O.; Heinrich, S.; Miteva, V.; Deen, N.G.; Kuipers, J.A.M.; Jacob, M.; Morl, L.

    2008-01-01

    Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Within this work the fluid dynamics of a novel spouted bed plant with two adjustable gas inlets is investigated. By analysis of

  16. Study on the relationship between uranium mine cage hoisting system and quality of inlet air

    Hu Penghua; Li Xianjie; Hong Changshou; Li Xiangyang

    2014-01-01

    Those skip hoisting shafts and cage hoisting shafts with over 100000-ton hoisting capacity per year can not be designed as air inlet shafts is particularly emphasized in nuclear industrial standard Technical Regulations for Radon Exhaustion and Ventilation in Underground Uranium Mine (EJ/T 359-2006) referring to previous production experiences of the former Soviet Union's uranium mines. Cage hoisting shafts are generally served as the main air inlet shafts for the widely adopted of exhaust ventilation in terms of uranium mines in China. Nevertheless, the above-mentioned standard has been considered as a constraint on designing and producing of China's prospective large uranium mines. Through theoretical analysis and field experiments on the main influencing factors over the quality of inlet air of selected experimental uranium mines hoisting system such as piston wind pressure, ore heap's radon emanation of shaft station, radon contamination of loaded mine cars etc, we finally established the calculation model of inlet air contamination deriving from ore heap and loaded mine cars' radon emanation in vertical shaft station. The acquired research achievements would lav a theoretical foundation for further works on revising relevant standards. (authors)

  17. Luminescent Measurement Systems for the Investigation of a Scramjet Inlet-Isolator

    Azam Che Idris

    2014-04-01

    Full Text Available Scramjets have become a main focus of study for many researchers, due to their application as propulsive devices in hypersonic flight. This entails a detailed understanding of the fluid mechanics involved to be able to design and operate these engines with maximum efficiency even at their off-design conditions. It is the objective of the present cold-flow investigation to study and analyse experimentally the mechanics of the fluid structures encountered within a generic scramjet inlet at M = 5. Traditionally, researchers have to rely on stream-thrust analysis, which requires the complex setup of a mass flow meter, a force balance and a heat transducer in order to measure inlet-isolator performance. Alternatively, the pitot rake could be positioned at inlet-isolator exit plane, but this method is intrusive to the flow, and the number of pitot tubes is limited by the model size constraint. Thus, this urgent need for a better flow diagnostics method is addressed in this paper. Pressure-sensitive paint (PSP has been applied to investigate the flow characteristics on the compression ramp, isolator surface and isolator sidewall. Numerous shock-shock interactions, corner and shoulder separation regions, as well as shock trains were captured by the luminescent system. The performance of the scramjet inlet-isolator has been shown to improve when operated in a modest angle of attack.

  18. Unsteady supercritical/critical dual flowpath inlet flow and its control methods

    Jun LIU

    2017-12-01

    Full Text Available The characteristics of unsteady flow in a dual-flowpath inlet, which was designed for a Turbine Based Combined Cycle (TBCC propulsion system, and the control methods of unsteady flow were investigated experimentally and numerically. It was characterized by large-amplitude pressure oscillations and traveling shock waves. As the inlet operated in supercritical condition, namely the terminal shock located in the throat, the shock oscillated, and the period of oscillation was about 50 ms, while the amplitude was 6 mm. The shock oscillation was caused by separation in the diffuser. This shock oscillation can be controlled by extending the length of diffuser which reduces pressure gradient along the flowpath. As the inlet operated in critical condition, namely the terminal shock located at the shoulder of the third compression ramp, the shock oscillated, and the period of oscillation was about 7.5 ms, while the amplitude was 12 mm. At this condition, the shock oscillation was caused by an incompatible backpressure in the bleed region. It can be controlled by increasing the backpressure of the bleed region. Keywords: Airbreathing hypersonic vehicle, Dual flowpath inlet, Terminal shock oscillation, Turbine based combined cycle, Unsteady flow

  19. Effects of gravity and inlet location on a two-phase countercurrent imbibition in porous media

    El-Amin, Mohamed; Salama, Amgad; Sun, S.

    2012-01-01

    We introduce a numerical investigation of the effect of gravity on the problem of two-phase countercurrent imbibition in porous media. We consider three cases of inlet location, namely, from, side, top, and bottom. A 2D rectangular domain is considered for numerical simulation. The results indicate that gravity has a significant effect depending on open-boundary location.

  20. The passive response of the Integral Fast Reactor concept to the chilled inlet accident

    Vilim, R.B.

    1990-01-01

    Simple methods are described for bounding the passive response of a metal fueled liquid-metal cooled reactor to the chilled inlet accident. Calculation of these bounds for a prototype of the Integral Fast Reactor concept shows that failure limits --- eutectic melting, sodium boiling and fuel pin failure --- are not exceeded. 2 refs., 1 fig., 2 tabs