WorldWideScience

Sample records for variable outfall conditions

  1. Wastewater Outfalls

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Outfalls which discharge wastewater from wastewater treatment facilities with individual NPDES permits. It does not include NPDES general permits.

  2. Assessment of plankton community and environmental conditions in São Sebastião Channel prior to the construction of a produced water outfall

    Directory of Open Access Journals (Sweden)

    Sônia Maria Flores Gianesella

    1999-01-01

    Full Text Available Plankton community and hydrological conditions were assessed as a part of ao environmental diagnosis in São Sebastião Channel, before the building of a submarine outfall of produced water from the oil maritime terminal of PETR08RÁS. Samples were collected in twenty oceanographic stations located in the oil terminal neighboring area, during the springtime of 1991. Oissolved inorganic nutrients and chlorophyll-a concentrations observed indicate an oligo-mesotrophic environment. Phenols and sulfides were absent, 800 values, except for three sampling points, were characteristic of unpolluted environments, although oil and grease were found in half of the sampled stations. Phytoplankton and zooplankton communities presented high diversity and evenness indices for the entire area. Phytoplankton was dominated by phytoflagel1àtes and zooplankton was dominated by copepods, mostly Paracalanus quasimodo. Plankton community composition was similar to that from adjacent regions under low anthropogenic influence.A comunidade planctônica e condições hidrológicas foram avaliadas como parte de um diagnóstico ambiental no Canal de São Sebastião, previamente à construção de um emissário submarino de água de produção, oriunda do terminal marítimo da PETROBRÁS. As amostras foram coletadas em vinte estações oceanográficas situadas na área adjacente ao terminal petrolífero, durante a primavera de 1991. As concentrações de nutrientes inorgânicos dissolvidos e de cIorofila-a obtidas, indicam um ambiente oligo-mesotrófico. Fenóis e sulfetos não foram detectados e os valores de 080, com exceção de três pontos, foram característicos de ambientes não poluídos, apesar da contaminação por óleos e graxas ter sido observada em metade das estações amostradas. O fito e o zooplâncton apresentaram altos índices de diversidade e equitatividade para toda área estudada. O fitoplâncton foi dominado por fitoflagelados, enquanto que o zoopl

  3. Ocean outfall plume characterization using an Autonomous Underwater Vehicle.

    Science.gov (United States)

    Rogowski, Peter; Terrill, Eric; Otero, Mark; Hazard, Lisa; Middleton, William

    2013-01-01

    A monitoring mission to map and characterize the Point Loma Ocean Outfall (PLOO) wastewater plume using an Autonomous Underwater Vehicle (AUV) was performed on 3 March 2011. The mobility of an AUV provides a significant advantage in surveying discharge plumes over traditional cast-based methods, and when combined with optical and oceanographic sensors, provides a capability for both detecting plumes and assessing their mixing in the near and far-fields. Unique to this study is the measurement of Colored Dissolved Organic Matter (CDOM) in the discharge plume and its application for quantitative estimates of the plume's dilution. AUV mission planning methodologies for discharge plume sampling, plume characterization using onboard optical sensors, and comparison of observational data to model results are presented. The results suggest that even under variable oceanic conditions, properly planned missions for AUVs equipped with an optical CDOM sensor in addition to traditional oceanographic sensors, can accurately characterize and track ocean outfall plumes at higher resolutions than cast-based techniques.

  4. Outfall K-018 TRC investigation

    International Nuclear Information System (INIS)

    Skiff, D.P.

    1994-01-01

    During 1993, 7 different samples taken at Reactor Outfall K-018 for Total Residual Chlorine exceeded the permitted requirement for the outfall of < 0.1 mg/L. Following the second exceedance, a Mitigation Action Plan was issued to investigate and identify the cause of the exceedances. The following potential causes were identified: (1) unauthorized/unknown operational discharge; (2) upstream industrial discharge to the Savannah River prior to SRS usage; (3) sanitary waste treatment plant discharge; (4) sampling methodology; (5) naturally occurring river water interference. Of these possibilities, it was determined that naturally occurring river water interference was the most likely cause and an in-depth sampling program, outlined in a Program Action Plan, was initiated to complete the investigation. The investigation determined that oxidized manganese present in the river water prior to usage within K-Area causes a false high reading for Total Residual Chlorine. It is this presence of the manganese interference, not operational discharge, that caused the exceedances at Outfall K-018

  5. Evaluating the effect of river restoration techniques on reducing the impacts of outfall on water quality

    Science.gov (United States)

    Mant, Jenny; Janes, Victoria; Terrell, Robert; Allen, Deonie; Arthur, Scott; Yeakley, Alan; Morse, Jennifer; Holman, Ian

    2015-04-01

    between metal types. Restored sites also showed lower variability in metal concentrations than un-restored sites, which is linked to greater bank stability and hence lower bank erosion rates within restored sites as eroding banks were noted to be a source of metal contaminants. The success of pollutant removal by set-back outfalls was varied due to additional factors including the distance between the set-back outfall and the main channel, vegetation type, density and age. The study highlights the ability of restoration techniques to reduce metal contaminant concentrations at outfalls, and provides an indication of the potential benefits from wider application of similar techniques.

  6. Region 9 NPDES Outfalls 2012

    Science.gov (United States)

    Point geospatial dataset representing locations of NPDES outfalls/dischargers for facilities which generally represent the site of the discharge. NPDES (National Pollution Discharge Elimination System) is an EPA permit program that regulates direct discharges from treated waste water that is discharged into waters of the US. Facilities are issued NPDES permits regulating their discharge as required by the Clean Water Act. A facility may have one or more dischargers. The location represents the discharge point of a discrete conveyance such as a pipe or man made ditch.

  7. Scalable conditional induction variables (CIV) analysis

    KAUST Repository

    Oancea, Cosmin E.; Rauchwerger, Lawrence

    2015-01-01

    challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow

  8. Marine outfall location off South Chennai

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Jayakumar, S.; AshokKumar, K.

    dilution and dispersion of the effluent can be achieved by locating the outfall appropriately. Study on the marine environmental parameters off south Chennai. Tamil Nadu, India near Mahabalipuram has been made to understand the environment and to suggest a...

  9. Aquatic invertebrate sampling at selected outfalls in Operable Unit 1082; Technical areas 9, 11, 16 and 22

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1995-09-01

    The Ecological Studies Team (EST) of ESH-20 at Los Alamos National Laboratory conducted preliminary aquatic sampling at outfalls within Operable Unit 1082 and nearby natural waterways. Eleven outfalls were sampled a total of eighteen times. Three natural waterways (upper Pajarito Canyon, Starmer`s Gulch, and Bulldog Spring) in the vicinity were sampled a total of six times. At most sites, EST recorded hydrological condition, physico-chemical parameters, wildlife uses, and vegetation. At each outfall with water and each natural waterway, EST collected an aquatic invertebrate sample which was analyzed by taxa composition, Wilhm`s biodiversity index, the community tolerance quotient (CTQ), and density. The physico-chemical parameters at most outfalls and natural waterways fell within the normal range of natural waters in the area. However, the outfalls are characterized by low biodiversity and severely stressed communities composed of a restricted number of taxa. The habitat at the other outfalls could probably support well-developed aquatic communities if sufficient water was available. At present, the hydrology at these outfalls is too slight and/or sporadic to support such a community in the foreseeable future. In contrast to the outfalls, the natural waterways of the area had greater densities of aquatic invertebrates, higher biodiversities, and lower CTQs.

  10. Bonneville Second Powerhouse Tailrace and High Flow Outfall: ADCP and drogue release field study; FINAL

    International Nuclear Information System (INIS)

    Cook, Chris B; Richmond, Marshall C; Guensch, Greg

    2001-01-01

    The Bonneville Project is one of four US Army Corps of Engineers operated dams along the Lower Columbia River. Each year thousands of smelt pass through this Project on their way to the Pacific Ocean. High flow outfalls, if specifically designed for fish passage, are thought to have as good or better smelt survival rates as spillways. To better understand the hydrodynamic flow field around an operating outfall, the Corps of Engineers commissioned measurement of water velocities in the tailrace of the Second Powerhouse. These data also are necessary for proper calibration and verification of three-dimensional numerical models currently under development at PNNL. Hydrodynamic characterization of the tailrace with and without the outfall operating was accomplished through use of a surface drogue and acoustic Doppler current profiler (ADCP). Both the ADCP and drogue were linked to a GPS (global positioning system); locating the data in both space and time. Measurements focused on the area nearest to the high flow outfall, however several ADCP transects and drogue releases were performed away from the outfall to document ambient flow field conditions when the outfall was not operating

  11. Sewage outfall plume dispersion observations with an autonomous underwater vehicle.

    Science.gov (United States)

    Ramos, P; Cunha, S R; Neves, M V; Pereira, F L; Quintaneiro, I

    2005-01-01

    This work represents one of the first successful applications of Autonomous Underwater Vehicles (AUVs) for interdisciplinary coastal research. A monitoring mission to study the shape and estimate the initial dilution of the S. Jacinto sewage outfall plume using an AUV was performed on July 2002. An efficient sampling strategy enabling greater improvements in spatial and temporal range of detection demonstrated that the sewage effluent plume can be clearly traced using naturally occurring tracers in the wastewater. The outfall plume was found at the surface highly influenced by the weak stratification and low currents. Dilution varying with distance downstream was estimated from the plume rise over the outfall diffuser until a nearly constant value of 130:1, 60 m from the diffuser, indicating the near field end. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a very effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated.

  12. Comparison of small mammal species diversity near wastewater outfalls, natural streams, and dry canyons

    International Nuclear Information System (INIS)

    Raymer, D.F.; Biggs, J.R.

    1994-03-01

    A wide range of plant and wildlife species utilizes water discharged from facilities at Los Alamos National Laboratory (LANL). The purpose of this study was to compare nocturnal small mammal communities at wet areas created by wastewater outfalls with communities in naturally created wet and dry areas. Thirteen locations within LANL boundaries were selected for small mammal mark-recapture trapping. Three of these locations lacked surface water sources and were classified as open-quotes dry,close quotes while seven sites were associated with wastewater outfalls (open-quotes outfallclose quotes sites), and three were located near natural sources of surface water (open-quotes naturalclose quotes sites). Data was collected on site type (dry, outfall or natural), location, species trapped, and the tag number of each individual captured. This data was used to calculate mean number of species, percent capture rate, and species diversity at each type of site. When data from each type of site was pooled, there were no significant differences in these variables between dry, outfall, and natural types. However, when data from individual sites was compared, tests revealed significant differences. All sites in natural areas were significantly higher than dry areas in daily mean number of species, percent capture rate, and species diversity. Most outfall sites were significantly higher than dry areas in all three variables tested. When volume of water from each outfall site was considered, these data indicated that the number of species, percent capture rate, and species diversity of nocturnal small mammals were directly related to the volume of water at a given outfall

  13. Electronic Out-fall Inspection Application - 12007

    Energy Technology Data Exchange (ETDEWEB)

    Weymouth, A Kent III; Pham, Minh; Messick, Chuck [Savannah River Nuclear Solutions, Aiken, South Carolina 29808 (United States)

    2012-07-01

    In early 2009 an exciting opportunity was presented to the Geographic Information Systems (GIS) team at the Savannah River Site (SRS). The SRS maintenance group was directed to maintain all Out-falls on Site, increasing their workload from 75 to 183 out-falls with no additional resources. The existing out-fall inspection system consisted of inspections performed manually and documented via paper trail. The inspections were closed out upon completion of activities and placed in file cabinets with no central location for tracking/trending maintenance activities. A platform for meeting new improvements required for documentation by the Department of Health and Environmental Control (DHEC) out-fall permits was needed to replace this current system that had been in place since the 1980's. This was accomplished by building a geographically aware electronic application that improved reliability of site out-fall maintenance and ensured consistent standards were maintained for environmental excellence and worker efficiency. Inspections are now performed via tablet and uploaded to a central point. Work orders are completed and closed either in the field using tablets (mobile application) or in their offices (via web portal) using PCs. And finally completed work orders are now stored in a central database allowing trending of maintenance activities. (authors)

  14. Outfall Pipeline Lines, Tutuila AS, 2009, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The outfalls extend from coastal points, originating from canneries and sewage treatment plants.Tafuna Outfall: This polyethylene pipeline installed in 1996, is...

  15. Copper Removal from A-01 Outfall by Ion Exchange

    International Nuclear Information System (INIS)

    Oji, L.N.

    1999-01-01

    Chelex100, a commercially available ion exchange resin, has been identified in this study as having a significant affinity for copper and zinc in the A-01 outfall water. Removal of copper and zinc from A-01 outfall water will ensure that the outfall meets the state of South Carolina's limit on these heavy metals

  16. Wave Induced Saline Intrusion in Sea Outfalls

    DEFF Research Database (Denmark)

    Larsen, Torben; Burrows, Richard

    1989-01-01

    Experimental and numerical studies have shown that the influence of wave increases the tendency of saline intrusion in multi-riser sea outfalls. The flow field in the diffusor under such unsteady and inhomogeneous circumstances is in general very complex, but when sufficient wave energy is dissip...

  17. Ocean outfalls as an alternative to minimizing risks to human and environmental health.

    Science.gov (United States)

    Feitosa, Renato Castiglia

    2017-06-01

    Submarine outfalls are proposed as an efficient alternative for the final destination of wastewater in densely populated coastal areas, due to the high dispersal capacity and the clearance of organic matter in the marine environment, and because they require small areas for implementation. This paper evaluates the probability of unsuitable bathing conditions in coastal areas nearby to the Ipanema, Barra da Tijuca and Icaraí outfalls based on a computational methodology gathering hydrodynamic, pollutant transport, and bacterial decay modelling. The results show a strong influence of solar radiation and all factors that mitigate its levels in the marine environment on coliform concentration. The aforementioned outfalls do not pollute the coastal areas, and unsuitable bathing conditions are restricted to nearby effluent launching points. The pollution observed at the beaches indicates that the contamination occurs due to the polluted estuarine systems, rivers and canals that flow to the coast.

  18. Nearshore circulation revealed by wastewater discharge from a submarine outfall, Aveiro Coast, Portugal

    Directory of Open Access Journals (Sweden)

    J. Figueiredo da Silva

    2002-01-01

    Full Text Available The morphological and climatic conditions of the Atlantic coast of northern Portugal result in a prevailing upwelling circulation over the continental shelf. A submarine outfall releases wastewater into the ocean c. 3 km directly offshore (at ∼16 m water depth from S. Jacinto, 5 km to the north of the inlet to the estuarine coastal lagoon system of the Ria de Aveiro. The buoyant plume has a distinctive reddish brown colour and is clearly visible at the water surface. The transport and dispersion of the plume was monitored by airborne photography and by in situ water sampling. Results revealed the surface currents present and water mass fronts in the nearshore zone of the Aveiro coast. During the spring and summer, the plume was not transported offshore in the manner expected by the upwelling shelf circulation. Instead, it was commonly observed to be transported alongshore with the prevailing southerly circulation or with an onshore component. The transport to the south caused the outfall plume to interact with the circulation associated with the tidal currents generated in the inlet channel to the Ria de Aveiro. The observations suggest that the trophic status of the Ria de Aveiro is unlikely to change because of the operation of the submarine outfall. Furthermore, this study demonstrates how simple observations of wastewater discharge from a submarine outfall can be used to improve understanding of nearshore circulation. Keywords: water circulation, upwelling, ocean outfall, remote sensing, eutrophication, Ria de Aveiro

  19. Scalable conditional induction variables (CIV) analysis

    DEFF Research Database (Denmark)

    Oancea, Cosmin Eugen; Rauchwerger, Lawrence

    2015-01-01

    parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.......Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as filter, or stack operations and pose significant challenges to automatic parallelization. Because...... the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same...

  20. Scalable conditional induction variables (CIV) analysis

    KAUST Repository

    Oancea, Cosmin E.

    2015-02-01

    Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as Alter, or stack operations and pose significant challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.

  1. Transport processes near coastal ocean outfalls

    Science.gov (United States)

    Noble, M.A.; Sherwood, C.R.; Lee, Hooi-Ling; Xu, Jie; Dartnell, P.; Robertson, G.; Martini, M.

    2001-01-01

    The central Southern California Bight is an urbanized coastal ocean where complex topography and largescale atmospheric and oceanographic forcing has led to numerous sediment-distribution patterns. Two large embayments, Santa Monica and San Pedro Bays, are connected by the short, very narrow shelf off the Palos Verdes peninsula. Ocean-sewage outfalls are located in the middle of Santa Monica Bay, on the Palos Verdes shelf and at the southeastern edge of San Pedro Bay. In 1992, the US Geological Survey, together with allied agencies, began a series of programs to determine the dominant processes that transport sediment and associated pollutants near the three ocean outfalls. As part of these programs, arrays of instrumented moorings that monitor currents, waves, water clarity, water density and collect resuspended materials were deployed on the continental shelf and slope information was also collected on the sediment and contaminant distributions in the region. The data and models developed for the Palos Verdes shelf suggest that the large reservoir of DDT/DDE in the coastal ocean sediments will continue to be exhumed and transported along the shelf for a long time. On the Santa Monica shelf, very large internal waves, or bores, are generated at the shelf break. The near-bottom currents associated with these waves sweep sediments and the associated contaminants from the shelf onto the continental slope. A new program underway on the San Pedro shelf will determine if water and contaminants from a nearby ocean outfall are transported to the local beaches by coastal ocean processes. The large variety of processes found that transport sediments and contaminants in this small region of the continental margin suggest that in regions with complex topography, local processes change markedly over small spatial scales. One cannot necessarily infer that the dominant transport processes will be similar even in adjacent regions.

  2. Tracer a application in marine outfall studies

    International Nuclear Information System (INIS)

    Genders, S.

    1979-01-01

    The applicability of radioactive and fluorescent tracers for field studies to predict or investigate waste water transport and dispersion from marine outfalls is evaluated. The application of either instantaneous or continuous tracer release, 'in situ' detection of tracers and data processing are considered. The necessity of a combined use of tracer techniques and conventional hydrographic methods for a statistical prediction of transport and dillution of waste water are pointed out. A procedure to determine an outlet distance from the coast, which satisfy bathing water criteria is outlined. (M.A.) [pt

  3. Radioactive and dye tracer studies for the NWNT sewerage outfall, Hong Kong, and comparison to near-field modelling

    International Nuclear Information System (INIS)

    Horton, P.R.; Wilson, J.R.

    1997-01-01

    A monitoring programme for the North West New Territories (NWNT) sewage outfall, located in the Urmston Road channel in Hong Kong, was completed in 1996. This included three surveys measuring effluent behaviour and oceanographic conditions near the outfall. Radioisotopes gold-198 (γ energy 0.42 MeV, half-life 2.7 days) and tritium (as tritiated water, HTO, β energy 0.018 MeV, half-life 12.3 years) were used to trace the effluent discharging from the outfall during both a wet season and dry season survey. The effluent was also simultaneously tagged with Rhodamine dye which was detected with fluorometers. The gold-198 was generally traced in real time using submersible detectors, while the tritium was measured in the laboratory from sea water samples using liquid scintillation techniques. The Radioisotopes and dye measurement techniques were progressively refined over the surveys and a reliable equipment arrangement and sampling procedure was established

  4. Locations of Combined Sewer Overflow Outfalls - US EPA Region 3

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies the locations of Combined sewer overflow outfalls. Combined sewer systems are sewers that are designed to collect rainwater runoff,...

  5. Effluent Mixing Modeling for Liquefied Natural Gas Outfalls in a Coastal Ecosystem

    Directory of Open Access Journals (Sweden)

    Mustafa Samad

    2014-06-01

    Full Text Available Liquid Natural Gas (LNG processing facilities typically are located on ocean shores for easy transport of LNG by marine vessels. These plants use large quantities of water for various process streams. The combined wastewater effluents from the LNG plants are discharged to the coastal and marine environments typically through submarine outfalls. Proper disposal of effluents from an LNG plant is essential to retain local and regional environmental values and to ensure regulatory and permit compliance for industrial effluents. Typical outfall designs involve multi-port diffuser systems where the design forms a part of the overall environmental impact assessment for the plant. The design approach needs to ensure that both near-field plume dispersion and far-field effluent circulation meets the specified mixing zone criteria. This paper describes typical wastewater process streams from an LNG plant and presents a diffuser system design case study (for an undisclosed project location in a meso-tidal coast to meet the effluent mixing zone criteria. The outfall is located in a coastal and marine ecosystem where the large tidal range and persistent surface wind govern conditions for the diffuser design. Physical environmental attributes and permit compliance criteria are discussed in a generic format. The paper describes the design approach, conceptualization of numerical model schemes for near- and far-field effluent mixing zones, and the selected diffuser design.

  6. Outfall as a Suitable Alternative for Disposal of Municipal Wastewater in Coastal Areas

    Directory of Open Access Journals (Sweden)

    Afshin Takdastan

    2005-11-01

    Full Text Available Disposal of raw municipal wastewater or effluent of preliminary treatment into the sea and ocean is economically more accepted and technically more efficient than secondary treatment. In this method, the wastewater disposed at the bottom of the sea in some points from diffuser. Nowadays, lots of researchers select outfall as a suitable alternative treatment method for coastal cities. The goal of this paper was to introduce the outfall as a wastewater treatment method and its design criteria considering different characteristics of the sea such as salinity, density, temperature, stratification etc. In addition, stagnant sea and thermal stratification is reviewed. In this paper the latest information were reviewed. In this alternative the wastewater treated under dilution, mixing and natural conditions. Moreover, sensitive coastal point are preserved from different wastewater pollutants. Usually, there is no limitation regarding discharge of coliform, DO, BOD, and nutrient concentrations in initial mixing zoom. The parameters such as thermal stratification, salinity stratification, density stratification, marine flows influence design of outfall.

  7. Outfall 51 air stripping feasibility study for the Reduction of Mercury in Plant Effluent (RMPE) Project. Revision 1

    International Nuclear Information System (INIS)

    1997-01-01

    Within the US Department of Energy's Oak Ridge Y-12 Plant there are a number of industrial wastewater discharge points or outfalls that empty into East Fork Poplar Creek (EFPC). EFPC originates within and runs continuously throughout the plant site and subsequently flows out the east end of the Y-12 Plant into the City of Oak Ridge. Mercury is present in outfall discharges due to contact of water with the soils surrounding past mercury-use buildings. As a result, the Reduction of Mercury in Plant Effluent (RMPE) Project was developed to achieve and maintain environmental compliance with regards to mercury, and, in particular with the National Pollutant Discharge Elimination System permit for the Y-12 Plant. To achieve a reduction in mercury loading to EFPC, a number of options have already been studied and implemented as part of the RMPE project. With the successful implementation of these options, Outfall 51 remains as a significant contributor to mercury load to EFPC. The primary purpose of this project is to determine the feasibility of removing mercury from contaminated spring water using air stripping. In order to accomplish this goal, a number of different areas were addressed. A pilot-scale unit was tested in the field using actual mercury-contaminated source water. Properties which impact the mercury removal via air stripping were reviewed to determine their effect. Also, enhanced testing was performed to improve removal efficiencies. Finally, the variable outfall flow was studied to size appropriate processing equipment for full-scale treatment

  8. Computer modelling for a new west coast sewage outfall

    International Nuclear Information System (INIS)

    Wallace, G.

    1975-06-01

    In order to assess the impact on coastal waters of a planned sewage outfall, tracer surveys have been carried out at selected sites. Both dye and radioactive tracers were used. Each survey consisted of a single instantaneous injection of tracer into the sea, followed by monitoring of the dispersion cloud of tracer from a boat. Measurements were later subject to computer analysis to enable coefficients of eddy diffusion and currents to be estimated. The area is subject to tidal influence, and currents suffer reversal in direction with the tides. Currents had previously been extensively evaluated by the use of in situ meters. In order to evaluate sewage fields, a numerical model was developed in which a continuous discharge was treated as a regular series of injections. The quantity of pollutant at a particular location was found by simply summing the amounts contributed by each dispersed injection which occurred during a fixed interval prior to the evaluation time in the tidal cycle. In this way, a dynamic picture of the sewage field for a planned discharge could be obtained. By including frequency of weather conditions, worst and average levels of pollution were estimated. (auth.)

  9. EPA Region 2 NPDES Municipal Separate Storm Sewer System Outfalls (MS4) GIS Layer

    Data.gov (United States)

    U.S. Environmental Protection Agency — This ArcGIS 10.3 point feature class contains identification, location, and outfall attributes including outfall size and receiving water body, and class information...

  10. Some Hydraulic and Environmental Aspects of Sea Outfalls

    DEFF Research Database (Denmark)

    Larsen, Torben

    The present work summarises the activities carried out by the author over a number of years in the area of environmental hydraulics in relation to sea outfalls for the discharge of sewage into the sea from urban areas through pipelines provided with diffusers. The substance of this monograph...

  11. Alternatives/action plan report for outfall 17

    International Nuclear Information System (INIS)

    1994-11-01

    This Document contains information pertaining to alternatives/action associated with controlling ammonia entering through outfall 17. This document identifies the location of contaminate source, the ammonia concentration levels entering East Fork Poplar Creek, and the action taken to reduce/eliminate the toxicity problem

  12. Alternatives/action plan report for outfall 17

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-11-01

    This Document contains information pertaining to alternatives/action associated with controlling ammonia entering through outfall 17. This document identifies the location of contaminate source, the ammonia concentration levels entering East Fork Poplar Creek, and the action taken to reduce/eliminate the toxicity problem.

  13. Effects of aging on blood pressure variability in resting conditions

    NARCIS (Netherlands)

    Veerman, D. P.; Imholz, B. P.; Wieling, W.; Karemaker, J. M.; van Montfrans, G. A.

    1994-01-01

    The objective of this study was to determine the effect of aging on beat-to-beat blood pressure and pulse interval variability in resting conditions and to determine the effect of aging on the sympathetic and vagal influence on the cardiovascular system by power spectral analysis of blood pressure

  14. Dynamic simulation of variable capacity refrigeration systems under abnormal conditions

    International Nuclear Information System (INIS)

    Liang Nan; Shao Shuangquan; Tian Changqing; Yan Yuying

    2010-01-01

    There are often abnormal working conditions at evaporator outlet of a refrigeration system, such as two-phase state in transient process, and it is essential to investigate such transient behaviours for system design and control strategy. In this paper, a dynamic lumped parameter model is developed to simulate the transient behaviours of refrigeration system with variable capacity in both normal and abnormal working conditions. The appropriate discriminant method is adopted to switch the normal and abnormal conditions smoothly and to eliminate the simulated data oscillation. In order to verify the dynamic model, we built a test system with variable frequency compressor, water-cooling condenser, evaporator and electronic expansion valve. Calculated values from the mathematical model show reasonable agreement with the experimental data. The simulation results show that the transient behaviours of the variable capacity refrigeration system in the abnormal working conditions can be calculated reliably with the dynamic model when the compressor rotary speed or the opening of electronic expansion valve changes abruptly.

  15. Removing Unnecessary Variables from Horn Clause Verification Conditions

    Directory of Open Access Journals (Sweden)

    Emanuele De Angelis

    2016-07-01

    Full Text Available Verification conditions (VCs are logical formulas whose satisfiability guarantees program correctness. We consider VCs in the form of constrained Horn clauses (CHC which are automatically generated from the encoding of (an interpreter of the operational semantics of the programming language. VCs are derived through program specialization based on the unfold/fold transformation rules and, as it often happens when specializing interpreters, they contain unnecessary variables, that is, variables which are not required for the correctness proofs of the programs under verification. In this paper we adapt to the CHC setting some of the techniques that were developed for removing unnecessary variables from logic programs, and we show that, in some cases, the application of these techniques increases the effectiveness of Horn clause solvers when proving program correctness.

  16. Creep behavior of Zircaloy cladding under variable conditions

    International Nuclear Information System (INIS)

    Matsuo, Y.

    1989-01-01

    Various creep tests of Zircaloy cladding tubes under variable conditions were conducted to investigate which hardening rule can be applicable for the creep behavior associated with condition changes. The results show that the strain-hardening rule is applicable in general when either the stress or temperature conditions change, provided that a certain amount of creep strain recovery is observed in case of stress drop. In stress reversal conditions, however, softening of the material was observed. Strain rate after stress reversal is much higher than that predicted by the strain-hardening rule. In this case, the modified strain-hardening model, considering a recoverable creep-hardening range together with the strain recovery, predicts the creep behavior well. The applicability of the model is ascertained through a verification test that includes stress reversal, strain recovery, stress changes, and temperature changes

  17. Statistical conditional sampling for variable-resolution video compression.

    Directory of Open Access Journals (Sweden)

    Alexander Wong

    Full Text Available In this study, we investigate a variable-resolution approach to video compression based on Conditional Random Field and statistical conditional sampling in order to further improve compression rate while maintaining high-quality video. In the proposed approach, representative key-frames within a video shot are identified and stored at full resolution. The remaining frames within the video shot are stored and compressed at a reduced resolution. At the decompression stage, a region-based dictionary is constructed from the key-frames and used to restore the reduced resolution frames to the original resolution via statistical conditional sampling. The sampling approach is based on the conditional probability of the CRF modeling by use of the constructed dictionary. Experimental results show that the proposed variable-resolution approach via statistical conditional sampling has potential for improving compression rates when compared to compressing the video at full resolution, while achieving higher video quality when compared to compressing the video at reduced resolution.

  18. Heavy metals in sediments from the Athens sewage outfall area

    International Nuclear Information System (INIS)

    Papakostidis, G.; Grimanis, A.P.; Zafiropoulos, D.; Griggs, G.B.; Hopkins, T.S.

    1975-01-01

    Sediments in the upper Saronikos Gulf have been contaminated by heavy metals from the discharge of untreated industrial and domestic wastewater from the area around Athens. Neutron activation analysis indicates concentrations of antimony, arsenic, chromium, gold, mercury, silver and zinc at 8 to 200 times greater than in the surrounding uncontaminated sediments. The bottom area affected by increased metal concentrations is at least 13km 2 and indicates a nearly radial dispersal pattern from the main outfall with higher concentrations extending to the southeast and southwest. (author)

  19. Polychlorinated Biphenyls in suspended-sediment samples from outfalls to Meandering Road Creek at Air Force Plant 4, Fort Worth, Texas, 2003-08

    Science.gov (United States)

    Braun, Christopher L.; Wilson, Jennifer T.

    2010-01-01

    engineering controls also is compared to the threshold effect concentration (TEC), the concentration below which adverse effects to benthic biota rarely occur. Sigma PCBc exceeded the TEC for 75 percent of the samples collected at outfall 4 and 67 percent of the samples collected at outfall 5 before the implementation of engineering controls. Sigma PCBc did not exceed the TEC in samples collected at either outfall 4 or outfall 5 after the implementation of engineering controls. The relative prominence of 10 selected PCB congeners was evaluated by graphical analysis of ratios of individual concentrations of the 10 PCB congeners to the sum of these PCB congeners. An overall decrease in concentrations of PCB congeners at outfalls 4 and 5 after implementation of engineering controls, as well as a shift in prominence from lighter, less chlorinated congeners to a heavier, more chlorinated congener might have resulted from the implementation of engineering controls. Because of the small number of samples collected and lack of runoff and precipitation data to evaluate comparability of sampling conditions before and after implementation of engineering controls, all conclusions are preliminary.

  20. Locations of Combined Sewer Overflow Outfalls - US EPA Region 3

    Science.gov (United States)

    This data layer identifies the locations of Combined sewer overflow outfalls. Combined sewer systems are sewers that are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. Most of the time, combined sewer systems transport all of their wastewater to a sewage treatment plant, where it is treated and then discharged to a water body. During periods of heavy rainfall or snowmelt, however, the wastewater volume in a combined sewer system can exceed the capacity of the sewer system or treatment plant. For this reason, combined sewer systems are designed to overflow occasionally and discharge excess untreated wastewater directly to nearby streams, rivers, or other water bodies. For further information visit: http://cfpub1.epa.gov/npdes/home.cfm?program_id=5

  1. Variable Width Riparian Model Enhances Landscape and Watershed Condition

    Science.gov (United States)

    Abood, S. A.; Spencer, L.

    2017-12-01

    Riparian areas are ecotones that represent about 1% of USFS administered landscape and contribute to numerous valuable ecosystem functions such as wildlife habitat, stream water quality and flows, bank stability and protection against erosion, and values related to diversity, aesthetics and recreation. Riparian zones capture the transitional area between terrestrial and aquatic ecosystems with specific vegetation and soil characteristics which provide critical values/functions and are very responsive to changes in land management activities and uses. Two staff areas at the US Forest Service have coordinated on a two phase project to support the National Forests in their planning revision efforts and to address rangeland riparian business needs at the Forest Plan and Allotment Management Plan levels. The first part of the project will include a national fine scale (USGS HUC-12 digits watersheds) inventory of riparian areas on National Forest Service lands in western United States with riparian land cover, utilizing GIS capabilities and open source geospatial data. The second part of the project will include the application of riparian land cover change and assessment based on selected indicators to assess and monitor riparian areas on annual/5-year cycle basis.This approach recognizes the dynamic and transitional nature of riparian areas by accounting for hydrologic, geomorphic and vegetation data as inputs into the delineation process. The results suggest that incorporating functional variable width riparian mapping within watershed management planning can improve riparian protection and restoration. The application of Riparian Buffer Delineation Model (RBDM) approach can provide the agency Watershed Condition Framework (WCF) with observed riparian area condition on an annual basis and on multiple scales. The use of this model to map moderate to low gradient systems of sufficient width in conjunction with an understanding of the influence of distinctive landscape

  2. Guaranteeing robustness of structural condition monitoring to environmental variability

    Science.gov (United States)

    Van Buren, Kendra; Reilly, Jack; Neal, Kyle; Edwards, Harry; Hemez, François

    2017-01-01

    Advances in sensor deployment and computational modeling have allowed significant strides to be recently made in the field of Structural Health Monitoring (SHM). One widely used SHM strategy is to perform a vibration analysis where a model of the structure's pristine (undamaged) condition is compared with vibration response data collected from the physical structure. Discrepancies between model predictions and monitoring data can be interpreted as structural damage. Unfortunately, multiple sources of uncertainty must also be considered in the analysis, including environmental variability, unknown model functional forms, and unknown values of model parameters. Not accounting for these sources of uncertainty can lead to false-positives or false-negatives in the structural condition assessment. To manage the uncertainty, we propose a robust SHM methodology that combines three technologies. A time series algorithm is trained using "baseline" data to predict the vibration response, compare predictions to actual measurements collected on a potentially damaged structure, and calculate a user-defined damage indicator. The second technology handles the uncertainty present in the problem. An analysis of robustness is performed to propagate this uncertainty through the time series algorithm and obtain the corresponding bounds of variation of the damage indicator. The uncertainty description and robustness analysis are both inspired by the theory of info-gap decision-making. Lastly, an appropriate "size" of the uncertainty space is determined through physical experiments performed in laboratory conditions. Our hypothesis is that examining how the uncertainty space changes throughout time might lead to superior diagnostics of structural damage as compared to only monitoring the damage indicator. This methodology is applied to a portal frame structure to assess if the strategy holds promise for robust SHM. (Publication approved for unlimited, public release on October-28

  3. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    P. E. Bachem

    2017-09-01

    Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  4. Environmental assessment for the A-01 outfall constructed wetlands project at the Savannah River Site

    International Nuclear Information System (INIS)

    1998-10-01

    The Department of Energy (DOE) prepared this environmental assessment (EA) to analyze the potential environmental impacts associated with the proposed A-01 outfall constructed wetlands project at the Savannah River site (SRS), located near aiken, South Carolina. The proposed action would include the construction and operation of an artificial wetland to treat effluent from the A-01 outfall located in A Area at SRS. The proposed action would reduce the outfall effluent concentrations in order to meet future outfall limits before these go into effect on October 1, 1999. This document was prepared in compliance with the National Environmental Policy Act (NEPA) of 1969, as amended; the requirements of the Council on Environmental Quality Regulations for Implementing NEPA (40 CFR Parts 1500--1508); and the DOE Regulations for Implementing NEPA (10 CFR Part 1021)

  5. Coral reef community, Mokapu Ocean Outfall, Oahu, HI 1998, (NODC Accession 0000173)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report provides the results of the first quantitative survey of the coral reef communities in the vicinity of the Mokapu Ocean Outfall in Kailua Bay, Oahu,...

  6. Aqueous mercury treatment technology review for NPDES Outfall 49 Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lanning, J.M.

    1993-04-01

    During 1950 to 1955, Building 9201-2 at the Oak Ridge Y-12 Plant was used to house development facilities for processes that employed elemental mercury to separate lithium isotopes as part of the thermonuclear weapons production operations. As a result of several spills, this building area and several other areas associated with the separation process were contaminated with mercury and became a source of continuing contamination of the Y-12 Plant discharge water to East Fork Poplar Creek (EFPC). Mercury concentrations in the outfalls south of Building 9201-2 have ranged up to 80 ppb, with the highest concentrations being experienced at Outfall 49. As a result, this outfall was chosen as a test site for future mercury treatment technology evaluation and development at the Oak Ridge Y-12 Plant. A literature review and vendor survey has identified several promising materials and technologies that may be applicable to mercury removal at the Outfall 49 site. This document summarizes those findings.

  7. Studies on waste field dilution in the vicinity of a marine outfall off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.; Zingde, M.D.

    Results are obtained using dimensional analysis to describe the characteristics of waste field at the marine outfall site off Bombay with a thrust on intermediate scale dispersion processes, which are of relevance to the assessment...

  8. National Pollution Discharge Elimination System (NPDES) Outfall Points, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for facilities which generally represent the site of the discharge. NPDES (National...

  9. National Pollution Discharge Elimination System (NPDES) Outfall Points, Region 9, 2011, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for facilities which generally represent the site of the discharge. NPDES (National...

  10. Estimation of the dilution field near a marine outfall by using effluent turbidity as an environmental tracer and comparison with dye tracer data.

    Science.gov (United States)

    Pecly, José Otavio Goulart

    2018-01-01

    The alternative use of effluent turbidity to determine the dilution field of a domestic marine outfall located off the city of Rio de Janeiro was evaluated through field work comprising fluorescent dye tracer injection and tracking with simultaneous monitoring of sea water turbidity. A preliminary laboratory assessment was carried out with a sample of the outfall effluent whose turbidity was measured by the nephelometric method before and during a serial dilution process. During the field campaign, the dye tracer was monitored with field fluorometers and the turbidity was observed with an optical backscattering sensor interfaced to an OEM data acquisition system. About 4,000 samples were gathered, covering an area of 3 km × 3 km near the outfall diffusers. At the far field - where a drift towards the coastline was observed - the effluent plume was adequately labeled by the dye tracer. The turbidity plume was biased due to the high and variable background turbidity of sea water. After processing the turbidity dataset with a baseline detrending method, the plume presented high correlation with the dye tracer plume drawn on the near dilution field. However, dye tracer remains more robust than effluent turbidity.

  11. The spatial variability in studies of soil physical condition

    International Nuclear Information System (INIS)

    Madero M, Edgar; Herrera G Oscar A; Castano C, Alirio

    2000-01-01

    The testing procedure was carried out in 1996-2 at the experimental station of the Universidad Nacional de Colombia in Palmira using vertical tillage (by chiseling) in coherent vertisol (typic Haplustert isohiperthermic fine loamy 1%). eight physical properties in depth of 15-25 cm were studied. the sampling methodology for soil physical properties and corn yield accounted the regionalized variable, and the analysis of results was carried out accounting a map of each variable. the results proved that geostatystics is versatile and give accuracy results. it showed in most of the area that vertical tillage was more favorable than conventional tillage to improve coherence (more soil penetrability without degradation) in seedbed zone. it was not found influence over corn yield. soil organic matter; clay and silt had influence over the soil response to mechanical strengths

  12. Site-specific variability in BTEX biodegradation under denitrifying conditions

    International Nuclear Information System (INIS)

    Kao, C.M.; Borden, R.C.

    1997-01-01

    Laboratory microcosm experiments were conducted to evaluate the feasibility of benzene, toluene, ethylbenzene, m-xylene, and o-xylene (BTEX) biodegradation under denitrifying conditions. Nine different sources of inocula, including contaminated and uncontaminated soil cores from four different sites and activated sludge, were used to establish microcosms. BTEX was not degraded under denitrifying conditions in microcosms inoculated with aquifer material from Rocky Point and Traverse City. However, rapid depletion of glucose under denitrifying conditions was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing aquifer material from Fort Bragg and Sleeping Bear Dunes and sewage sludge. Benzene was recalcitrant in all microcosms tested. The degradation of o-xylene ceased after toluene, ethylbenzene, and m-xylene were depleted in the Fort Bragg and sludge microcosms, but o-xylene continued to degrade in microcosms with contaminated Sleeping Bear Dunes soil. The most probable number (MPN) of denitrifiers in these nine different inocula were measured using a microtiter technique. There was no correlation between the MPN of denitrifiers and the TEX degradation rate under denitrifying conditions. Experimental results indicate that the degradation sequence and TEX degradation rate under denitrifying conditions may differ among sites. Results also indicate that denitrification alone may not be a suitable bioremediation technology for gasoline-contaminated aquifers because of the inability of denitrifiers to degrade benzene

  13. A method for calorimetric analysis in variable conditions heating

    International Nuclear Information System (INIS)

    Berthier, G.

    1965-01-01

    By the analysis of the thermal transition conditions given by the quenching of a sample in a furnace maintained at a high temperature, it is possible to study the thermal diffusivity of some materials and those of solid state structure transformation on a qualitative as well as a quantitative standpoint. For instance the transformation energy of α-quartz into β-quartz and the Wigner energy stored within neutron-irradiated beryllium oxide have been measured. (author) [fr

  14. Variability of Bed Load Components in Different Hydrological Conditions

    Directory of Open Access Journals (Sweden)

    Hossein Kheirfam

    2017-04-01

    New hydrological insights: We found that the amount of the minimum, the mean and the maximum bed load were 3 × 10−8, 6.15 × 10−4± 7.17 × 10−4 and 4.38 × 10−3 kg s−1, respectively. The minimum, the mean, and the maximum discharge were also 60, 334 ± 215.56 and 780 l s−1, respectively. In low discharge conditions during summer, the fine grain sediments had the largest amount of bed load sediment. Coarse and medium-grained sediment transportation was higher in autumn and the early winter consistent with the occurrence of extreme rainfall and flood flows.

  15. Upgrading of coker distillate under variable hydrotreating operating conditions

    Directory of Open Access Journals (Sweden)

    H.A. Elsayed

    2011-06-01

    Full Text Available Studies on hydrotreating coker distillates, produced from a delayed coker unit were done using a commercially available CoMo/γ-Al2O3 catalyst, on which 0.2 wt% P2O5 was added in order to improve its characteristics. The experimental studies were conducted in a fixed-bed continuous-reactor (cata-test unit at temperatures (300–400 °C and total hydrogen pressure (40–65 bar. These conditions have affected the feedstock characteristics and great reduction of sulfur, aromatics and boiling ranges. Other improvements were obtained in diesel index (DI due to hydrogenation reaction of aromatics and desulfurization of its sulfur contents.

  16. Diffuser Design for Marine Outfalls in Areas with Strong Currents, High waves and Sediment Transport

    DEFF Research Database (Denmark)

    Larsen, Torben

    1995-01-01

    The design of marine outfalls is often based on environmental criteria for a minimum initial dilution. Accordingly advanced diffuser arrangement are designed to fulfil these requirements. A large number of examples of malfunction and blocking in sea outfalls have occurred around the world...... as a result of this uncompromising consent to environmental demands. Two examples of unconventional design are given in this paper. Both cases involved risk of blockage of the diffuser section because of wave and current induced sediment transport The paper also discusses how acceptable far field dilution...

  17. Modeling of Sediment Transport and Self-Cleansing in Sea Outfalls

    DEFF Research Database (Denmark)

    Larsen, Torben; Ibro, I.

    2011-01-01

    The paper describes an on-going project on modeling of sediment transport in outfalls with special focus on the self-cleansing problem occurring due to the daily flow variations seen in outfalls. The two central elements of the project is the development of the numerical model and a matching...... physical model in the laboratory. The numerical model covers both sediment transport over bed accumulations as well as transport over clean bottom. The physical modeling emphasizes on measurement of the non-steady removal and transport of welldefined and limited accumulations along the pipe. The paper...

  18. Relationships between tuna catch and variable frequency oceanographic conditions

    Directory of Open Access Journals (Sweden)

    F. I. Ormaza-González

    2016-08-01

    Full Text Available Skipjack (Katsuwunus pelamis, yellow fin (Thunnus albacares and albacore (Thunnus alulunga tunas landed in the Eastern Pacific Ocean (EPO countries and Ecuador were correlated to the Indexes Oceanic El Niño (ONI and Multivariate Enso Index (MEI. The temporal series 1983–2012, and 1977–1999 (warm Pacific Decadal Oscillation, PDO, and 2000–2012 (cold PDO were analyzed. Linear correlation showed that at least 11 % of the total landings were associated with the MEI, with a slightly negative gradient from cold to warm conditions. When non-linear regression (n  =  6, the R2 was higher up to 0.304 (MEI, r =  0.551. The correlation shows high spread from −0.5 to +0.5 for both MEI/ONI; the highest landings occurred at 0.34–0.45; both indexes suggested that at extreme values < −1.0 and > 1.1 total landings tend to decrease. Landings were associated up to 21.9 % (MEI in 2000–2012, 1983–1999 rendered lower R2 (< 0.09; i.e., during cold PDO periods there was a higher association between landings and oceanographic conditions. For the non-linear regression (n  =  6 a R2 of 0.374 (MEI and 0.408 (ONI were registered, for the 2000–2012, a higher R2 was observed in 1983–1999, 0.443 and 0.711 for MEI and ONI respectively, suggesting that is better to analyze split series (1983–1999, 2000–2012 than as a whole (1983–2012, due to noise produced by the transition from hot to cold PDOs. The highest landings were in the range −0.2 to 0.5 for MEI/ONI. The linear regression of skipjack landings in Ecuador gave an R2 of 0.140 (MEI and 0.066 (ONI and the non-linear were 0.440 and 0.183 respectively. Total landings in the EPO associated to oceanographic events of high and low frequencies could be used somehow as predictors of the high El Niño o La Niña. There is a clear evidence that tuna fish biomass are at higher levels when the PDO is on cold phase (2000–2030 and vice versa on warm phase (1980–1999. The

  19. Pollution from urban development and setback outfalls as a catchment management measure for river water quality improvement

    Science.gov (United States)

    Allen, Deonie; Haynes, Heather; Arthur, Scott

    2016-04-01

    Urban development causes an increase in fine sediment and heavy metal stormwater pollution. Pollution load estimation theorises that stormwater pollutant load and type are strongly, directly influenced by contributing catchment land use. The research presented investigates the validity of these assumptions using an extensive novel field data set of 53 catchments. This research has investigated the relationships between land use and pollutant concentrations (Cu, Zn, Pb, Ni, Ca, Ba, Sn, Mn) in urban stormwater outfall sediments. Cartographic and aerial photography data have been utilised to delineate the surface and subsurface contributing catchment land use. A zoned sub-catchment approach to catchment characterisation of stormwater pollutant concentration has been defined and tested. This method effectively describes the specific land use influence on pollutant concentrations at the stormwater outfall, showing strong dependency with road length, brake points, impervious area and open space. Road networks and open space are found to influence land use, and thus stormwater pollution, closer to stormwater outfall/receiving waterbody suggesting storage, treatment, assimilation, loss or dilution of the land use influence further away from stormwater outfall. An empirical description has been proposed with which to predict outfall pollutant contributions to the receiving urban waterbody based on catchment land use information. With the definition and quantification of contributing catchment specific fine sediment and urban heavy metal pollutants, the influence of urban stormwater outfall management on the receiving watercourse has been considered. The locations of stormwater outfalls, and their proximity to the receiving waterway, are known as key water quality and river health influences. Water quality benefits from the implementation of stormwater outfalls set back from the receiving waterway banks have been investigated using the catchment case study. Setback outfalls

  20. Acceptability of sewerage outfalls in accordance with the new water laws

    Energy Technology Data Exchange (ETDEWEB)

    Czychowski, M

    1980-01-01

    In more than one respect, sewerage outfalls must be seen in a different light since the fourth amendment to the water resources policy act was passed on April 24th 1976, which incorporated the sewerage taxation law of September 13th 1976 and its administrative by-laws. A review on the situation to date is given.

  1. [Estimate the abatement rate of septic tank sewage outfall soil on nitrogen pollutants of typical farmer household sewage].

    Science.gov (United States)

    Zhou, Feng; Wang, Wen-Lin; Wang, Guo-Xiang; Ma, Jiu-Yuan; Wan, Yin-Jing; Tang, Xiao-Yan; Liang, Bin; Ji, Bin

    2013-10-01

    The surface soil on sewage outfall and effluent of farmer household septic tank were collected in situ from the typical region of plain river network areas in Taihu Lake Basin, and the typical rainfall (summer 30 mm . times-1, winter 5 mm times -1), temperature (summer 27 degrees C, winter 5 degrees C ) condition and pollutant load were artificial simulated by indoor simulation soil column experiments for estimating nitrogen abatement rate of rural sewage treated by the outfall soil and exploring the abatement rule in different seasons and weather process (7 days before the rain, 3 rainy days, 7 days after the rain). Results showed that: there was the significant difference (P 0. 05). Therefore, the TN, NH+4 -N abatement rate, NO-3 -N increase rate need to be divided by seasons, TN abatement rate, NO-3 -N increase rate of summer need to be divided by the weather process, which were 38.5% , - 25.0% , 46. 0% and 478. 1%, 913.8%, 382. 0% , before the rain, in rainy day, after the rain, respectively; while the NH+4 -N abatement rate of summer and the TN, NH+4 -N abatement rate, NO-3 -N increase rate of winter do not need to be divided by weather process, were 91.7% , 50.4% , 85.5% and 276.0% , respectively. In the summer, the TN abatement rate in different weather processes was not correlated with NH+4 -N abatement rate, but significantly negative correlated with NO-3 -N increase rate. In the winter, the stable accumulation of TN in soil was an important reason of the TN abatement rate which had no significant difference and kept a high level among different weather processes, and it was closely related to the stable accumulation of NH+4 -N in soil.

  2. 13 CFR 120.214 - What conditions apply for variable interest rates?

    Science.gov (United States)

    2010-01-01

    ... interest rates? 120.214 Section 120.214 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Policies Specific to 7(a) Loans Maturities; Interest Rates; Loan and Guarantee Amounts § 120.214 What conditions apply for variable interest rates? A Lender may use a variable rate of interest...

  3. Variability in Second Language Learning: The Roles of Individual Differences, Learning Conditions, and Linguistic Complexity

    Science.gov (United States)

    Tagarelli, Kaitlyn M.; Ruiz, Simón; Vega, José Luis Moreno; Rebuschat, Patrick

    2016-01-01

    Second language learning outcomes are highly variable, due to a variety of factors, including individual differences, exposure conditions, and linguistic complexity. However, exactly how these factors interact to influence language learning is unknown. This article examines the relationship between these three variables in language learners.…

  4. Online optimal control of variable refrigerant flow and variable air volume combined air conditioning system for energy saving

    International Nuclear Information System (INIS)

    Zhu, Yonghua; Jin, Xinqiao; Du, Zhimin; Fang, Xing

    2015-01-01

    The variable refrigerant flow (VRF) and variable air volume (VAV) combined air conditioning system can solve the problem of the VRF system in outdoor air ventilation while taking advantage of its high part load energy efficiency. Energy performance of the combined air conditioning system can also be optimized by joint control of both the VRF and the VAV parts. A model-based online optimal control strategy for the combined air conditioning system is presented. Simplified adaptive models of major components of the combined air conditioning system are firstly developed for predicting system performances. And a cost function in terms of energy consumption and thermal comfort is constructed. Genetic algorithm is used to search for the optimal control sets. The optimal control strategy is tested and evaluated through two case studies based on the simulation platform. Results show that the optimal strategy can effectively reduce energy consumption of the combined air conditioning system while maintaining acceptable thermal comfort. - Highlights: • A VRF and VAV combined system is proposed. • A model-based online optimal control strategy is proposed for the combined system. • The strategy can reduce energy consumption without sacrificing thermal comfort. • Novel simplified adaptive models are firstly developed for the VRF system

  5. Benthic faunal sampling adjacent to the Barbers Point ocean outfall, Oahu, Hawaii, 1986-2010 (NODC Accession 9900098)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic fauna in the vicinity of the Barbers Point (Honouliuli) ocean outfall were sampled from 1986-2010. To assess the environmental quality, sediment grain size...

  6. Benthic faunal sampling adjacent to the Sand Island ocean outfall, Oahu, Hawaii, 1986-2010 (NODC Accession 9900088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic fauna in the vicinity of the Sand Island ocean outfall were sampled from 1986-2010. To assess the environmental quality, sediment grain size and sediment...

  7. Results of Toxicity Studies Conducted on Outfall X-08 and Its Contributing Waste Streams, November 1999 - June 2000

    International Nuclear Information System (INIS)

    Specht, W.L.

    2000-01-01

    This interim report summarizes the results of toxicity tests, Toxicity Identification Evaluations, and chemical analyses that have been conducted on SRS's NPDES Outfall X-08 and its contributing waste streams between November 1999 and June 2000

  8. BOD-DO modeling and water quality analysis of a waste water outfall off Kochi, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Babu, M.T.; Das, V.K.; Vethamony, P.

    Water quality scenarios around an offshore outfall off Kochi were simulated using MIKE21 water quality model, assuming a high Biochemical Oxygen Demand (BOD=50 mgl sup(-1)) effluent discharge. The discharge is introduced into the model through...

  9. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  10. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2007, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  11. National Pollution Discharge Elimination System (NPDES) Wastewater Treatment Plant Outfall Points, Region 9, 2011, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Point geospatial dataset representing locations of NPDES outfalls/dischargers for waste water treatment plants which generally represent the site of the discharge....

  12. CHRONIC ZINC SCREENING WATER EFFECT RATIO FOR THE H-12 OUTFALL, SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, D.; Looney, B.; Millings, M.

    2009-01-13

    In response to proposed Zn limits for the NPDES outfall H-12, a Zn screening Water Effects Ratio (WER) study was conducted to determine if a full site-specific WER is warranted. Using standard assumptions for relating the lab results to the stream, the screening WER data were consistent with the proposed Zn limit and suggest that a full WER would result in a similar limit. Addition of a humate amendment to the outfall water reduced Zn toxicity, but the toxicity reduction was relatively small and unlikely to impact proposed Zn limits. The screening WER data indicated that the time and expense required to perform a full WER for Zn is not warranted.

  13. Temperature optimum of algae living in the outfall of a power plant on Lake Monona

    International Nuclear Information System (INIS)

    Brock, T.D.; Hoffmann, J.

    1974-01-01

    Temperature optima for photosynthesis were measured for algal populations living in the outfall of a fossil-fuel electric power plant on Lake Monona and were compared with the temperature optima of algae living in a control area in the nearby Yahara River. The temperature of the power plant outfall averaged about 8 0 C higher than that of the Yahara River. In the winter, no differences in species composition between the two study areas could be detected, Cladophora and Ulothrix being the dominant algae. The temperature optima of the populations from the two locations were the same, around 27 0 C, although the habitat temperatures at both locations were considerably lower. The only difference in response to temperature seen between the two populations was that the population at the outfall was able to photosynthesize at higher temperature, still showing high photosynthesis at 35 0 C and detectable photosynthesis at 46 0 C, a temperature at which the population from the Yahara River showed no detectable photosynthesis. In the summer, the dominant algae at the power plant outfall were Stigeoclonium and filamentous blue-green algae (family Oscillatoriaceae), whereas at the Yahara River the algal population was almost exclusively Cladophora. The temperature optima of both summer populations were the same, 31.5 0 C, only slightly higher than the mid-winter optima. Again, the population from the power plant was able to photosynthesize at higher temperature than the control population, showing quite active photosynthesis at 42.5 0 C, a temperature at which the population from the Yahara River was completely inactive. (U.S.)

  14. Spectral Kurtosis Entropy and Weighted SaE-ELM for Bogie Fault Diagnosis under Variable Conditions

    Directory of Open Access Journals (Sweden)

    Zhipeng Wang

    2018-05-01

    Full Text Available Bogies are crucial for the safe operation of rail transit systems and usually work under uncertain and variable operating conditions. However, the diagnosis of bogie faults under variable conditions has barely been discussed until now. Thus, it is valuable to develop effective methods to deal with variable conditions. Besides, considering that the normal data for training are much more than the faulty data in practice, there is another problem in that only a small amount of data is available that includes faults. Concerning these issues, this paper proposes two new algorithms: (1 A novel feature parameter named spectral kurtosis entropy (SKE is proposed based on the protrugram. The SKE not only avoids the manual post-processing of the protrugram but also has strong robustness to the operating conditions and parameter configurations, which have been validated by a simulation experiment in this paper. In this paper, the SKE, in conjunction with variational mode decomposition (VMD, is employed for feature extraction under variable conditions. (2 A new learning algorithm named weighted self-adaptive evolutionary extreme learning machine (WSaE-ELM is proposed. WSaE-ELM gives each sample an extra sample weight to rebalance the training data and optimizes these weights along with the parameters of hidden neurons by means of the self-adaptive differential evolution algorithm. Finally, the hybrid method based on VMD, SKE, and WSaE-ELM is verified by using the vibration signals gathered from real bogies with speed variations. It is demonstrated that the proposed method of bogie fault diagnosis outperforms the conventional methods by up to 4.42% and 6.22%, respectively, in percentages of accuracy under variable conditions.

  15. A Second-Order Conditionally Linear Mixed Effects Model with Observed and Latent Variable Covariates

    Science.gov (United States)

    Harring, Jeffrey R.; Kohli, Nidhi; Silverman, Rebecca D.; Speece, Deborah L.

    2012-01-01

    A conditionally linear mixed effects model is an appropriate framework for investigating nonlinear change in a continuous latent variable that is repeatedly measured over time. The efficacy of the model is that it allows parameters that enter the specified nonlinear time-response function to be stochastic, whereas those parameters that enter in a…

  16. Impaired Behavior Regulation under Conditions of Concurrent Variable Schedules of Reinforcement in Children with ADHD

    Science.gov (United States)

    Taylor, David; Lincoln, Alan J.; Foster, Sharon L.

    2010-01-01

    Objective: To bridge theory of response inhibition and learning in children with ADHD. Method: Thirty ADHD and 30 non-ADHD children (ages 9-12) were compared under concurrent variable interval (VI-15 sec., VI-30 sec. and VI- 45 sec.) reinforcement schedules that required the child to switch between the three schedules under conditions of…

  17. Land agroecological quality assessment in conditions of high spatial soil cover variability at the Pereslavskoye Opolye.

    Science.gov (United States)

    Morev, Dmitriy; Vasenev, Ivan

    2015-04-01

    The essential spatial variability is mutual feature for most natural and man-changed soils at the Central region of European territory of Russia. The original spatial heterogeneity of forest soils has been further complicated by a specific land-use history and human impacts. For demand-driven land-use planning and decision making the quantitative analysis and agroecological interpretation of representative soil cover spatial variability is an important and challenging task that receives increasing attention from private companies, governmental and environmental bodies. Pereslavskoye Opolye is traditionally actively used in agriculture due to dominated high-quality cultivated soddy-podzoluvisols which are relatively reached in organic matter (especially for conditions of the North part at the European territory of Russia). However, the soil cover patterns are often very complicated even within the field that significantly influences on crop yield variability and have to be considered in farming system development and land agroecological quality evaluation. The detailed investigations of soil regimes and mapping of the winter rye yield have been carried in conditions of two representative fields with slopes sharply contrasted both in aspects and degrees. Rye biological productivity and weed infestation have been measured in elementary plots of 0.25 m2 with the following analysis the quality of the yield. In the same plot soil temperature and moisture have been measured by portable devices. Soil sampling was provided from three upper layers by drilling. The results of ray yield detailed mapping shown high differences both in average values and within-field variability on different slopes. In case of low-gradient slope (field 1) there is variability of ray yield from 39.4 to 44.8 dt/ha. In case of expressed slope (field 2) the same species of winter rye grown with the same technology has essentially lower yield and within-field variability from 20 to 29.6 dt/ha. The

  18. Potential electricity savings by variable speed control of compressor for air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Nasution, Henry [Bung Hatta University, Department of Mechanical Engineering, Faculty of Industrial Engineering, Padang, West Sumatera (Indonesia); Wan Hassan, Mat Nawi [Universiti Teknologi Malaysia, Faculty of Mechanical Engineering, Skudai, Johor Bahru-Darul Ta' zim (Malaysia)

    2006-05-15

    The potential of a variable-speed compressor running on a controller to provide enhanced load-matching capability, energy saving and thermal comfort for application in air-conditioning system is demonstrated. An air-conditioning system, originally operated on a constant speed mode, is retrofitted with an inverter and a PID controller. The system was installed to a thermal environmental room together with a data acquisition system to monitor energy consumption and temperature of the room. Measurements were taken 2 h daily at a time interval of 5 min for an on/off and an inverter variable-speed conditions. The results indicate that thermal comfort of the room together with energy saving can be obtained through a proper selection of K for the controller. At a temperature setting of 22 C, the energy saving for the system is estimated to reach 25.3% for PID controllers. (orig.)

  19. Real-time Continuous Assessment Method for Mental and Physiological Condition using Heart Rate Variability

    Science.gov (United States)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

  20. Water Quality Monitoring Around Submerged Wastewater Outfalls in Southern California: From Compliance Assessment to Impact of Climate Change

    Science.gov (United States)

    Nezlin, N. P.

    2016-02-01

    Routine monitoring near major submerged ocean outfalls in southern California is focused on the assessment of the effects of wastewater discharge on water-quality (WQ), including dissolved oxygen, pH, transmissivity, and phytoplankton biomass. The proposed WQ compliance assessment using DO as an indicator includes 1) identification of the area affected by effluent wastewater using Colored Dissolved Organic Matter (CDOM) as an effluent plume tracer, 2) selection of reference sampling sites representing `natural' conditions, and 3) comparison between DO profiles in the reference and plume-affected zones. This strategy is implemented as an interactive web-based tool including convenient data visualization options. At the same time, the data of WQ monitoring (regular quarterly observations starting 1998-present) provides an excellent platform to analyze the spatial and temporal (seasonal and interannual) variations in near-shore ocean ecosystem. An illustrative example is the trends in the depths of the euphotic layer and subsurface chlorophyll maximum layer (SCML), abruptly deepening during the most recent four-year period (2011-2014). These dramatic changes are associated with declining intensity of the North Pacific gyre circulation (NPGO index), decreasing upwelling and increasing transport of warm water from equatorial Pacific (PDO and ENSO cycles).

  1. Full scale evaluation of combined sewer overflows disinfection using performic acid in a sea-outfall pipe

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Flagstad, Rasmus; Sonne Munch, Ebbe

    2015-01-01

    methods are known and each has problems. This work evaluated for the first time the full-scale disinfection using performic acid by the removal of the two currently regulated indicator bacteria for bathing water quality, E. coli and Enterococcus. Experiments were performed at a sewage bypass through a sea......-outfall pipe with a minimum hydraulic retention time of 24 min. The disinfection efficiency in the field was measured by analyzing samples taken before and after the treatment. Samples were also treated with performic acid in the laboratory to measure the disinfection effectiveness and kinetic of degradation...... of performic acid. Doses of 1-8 ppm of performic acid achieved 1.0-3.5 log removal of E coli and 1.0-2.44 log removal of Enterococcus in the field, but were somewhat higher in laboratory conditions at 1.69-4.38 and 1.0-4.27 log units, respectively. Studies of the degradation of performic acid in collected real...

  2. Determination of diffusion parameters using radioactive tracers, aiming at a project of a submarine sewage outfall

    International Nuclear Information System (INIS)

    Santos, J.L. dos.

    1979-01-01

    Radioactive tracers technology is applied to pollutant dispersion studies in water bodies, for the project of submarine sewage outfall. The models proposed by Hansen/Harremoes and Okubo, respectively, for the prediction of physical dilution rates and determination of turbulent diffusion laws, are discussed. The methodology for field work as well as data processing is described. The results from field investigations carried out in Brazilian litoral waters for submarine release of sewage in Santos - Sao Vicente, Guaruja and Maceio, are presented and commented. (Author) [pt

  3. Offshore Variability in Critical Weather Conditions in Large-Scale Wind Based Danish Power System

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2013-01-01

    of the variability for the 2020 Danish power system, one can see that in the worst case, up to 1500 MW of power can be lost in 30 minutes. We present results showing how this issue is partially solved by the new High Wind Storm Controller presented by Siemens in the TWENTIES project.......Offshore wind power has a significant development potential, especially in North Europe. The geographical concentration of offshore wind power leads to increased variability and in the case of critical weather conditions it may lead to sudden and considerable loss of production. In this context......, the chances of losing several GW of wind power due to critical weather conditions in a very short time period could potentially jeopardize the whole system’s reliability and stability. Forecasting such events is not trivial and the results so far are not encouraging. When assessing the impact...

  4. Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil)

    KAUST Repository

    Roth, Florian; Lessa, G.C.; Wild, C.; Kikuchi, R.K.P.; Naumann, M.S.

    2016-01-01

    Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ13Corg and δ15N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6 km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality.

  5. Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil)

    KAUST Repository

    Roth, Florian

    2016-03-30

    Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ13Corg and δ15N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6 km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality.

  6. Premix fuels study applicable to duct burner conditions for a variable cycle engine

    Science.gov (United States)

    Venkataramani, K. S.

    1978-01-01

    Emission levels and performance of a premixing Jet-A/air duct burner were measured at reference conditions representative of take-off and cruise for a variable cycle engine. In a parametric variation sequence of tests, data were obtained at inlet temperatures of 400, 500 and 600K at equivalence ratios varying from 0.9 to the lean stability limit. Ignition was achieved at all the reference conditions although the CO levels were very high. Significant nonuniformity across the combustor was observed for the emissions at the take-off condition. At a reference Mach number of 0.117 and an inlet temperature of 600K, corresponding to a simulated cruise condition, the NOx emission level was approximately 1 gm/kg-fuel.

  7. Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

    Science.gov (United States)

    Verrot, Lucile; Destouni, Georgia

    2015-01-01

    Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

  8. Photoplethysmography pulse rate variability as a surrogate measurement of heart rate variability during non-stationary conditions

    International Nuclear Information System (INIS)

    Gil, E; Orini, M; Bailón, R; Laguna, P; Vergara, J M; Mainardi, L

    2010-01-01

    In this paper we assessed the possibility of using the pulse rate variability (PRV) extracted from the photoplethysmography signal as an alternative measurement of the HRV signal in non-stationary conditions. The study is based on analysis of the changes observed during a tilt table test in the heart rate modulation of 17 young subjects. First, the classical indices of HRV analysis were compared to the indices from PRV in intervals where stationarity was assumed. Second, the time-varying spectral properties of both signals were compared by time-frequency (TF) and TF coherence analysis. Third, the effect of replacing PRV with HRV in the assessment of the changes of the autonomic modulation of the heart rate was considered. Time-invariant HRV and PRV indices showed no statistically significant differences (p > 0.05) and high correlation (>0.97). Time-frequency analysis revealed that the TF spectra of both signals were highly correlated (0.99 ± 0.01); the difference between the instantaneous power, in the LF and HF bands, obtained from HRV and PRV was small (<10 −3 s −2 ) and their temporal patterns were highly correlated (0.98 ± 0.04 and 0.95 ± 0.06 in the LF and HF bands, respectively) and TF coherence in the LF and HF bands was high (0.97 ± 0.04 and 0.89 ± 0.08, respectively). Finally, the instantaneous power in the LF band was observed to significantly increase during head-up tilt by both HRV and PRV analysis. These results suggest that although some differences in the time-varying spectral indices extracted from HRV and PRV exist, mainly in the HF band associated with respiration, PRV could be used as a surrogate of HRV during non-stationary conditions, at least during the tilt table test

  9. Equivalent conditions of complete moment convergence for extended negatively dependent random variables

    Directory of Open Access Journals (Sweden)

    Qunying Wu

    2017-05-01

    Full Text Available Abstract In this paper, we study the equivalent conditions of complete moment convergence for sequences of identically distributed extended negatively dependent random variables. As a result, we extend and generalize some results of complete moment convergence obtained by Chow (Bull. Inst. Math. Acad. Sin. 16:177-201, 1988 and Li and Spătaru (J. Theor. Probab. 18:933-947, 2005 from the i.i.d. case to extended negatively dependent sequences.

  10. Fault Diagnosis for Rolling Bearings under Variable Conditions Based on Visual Cognition.

    Science.gov (United States)

    Cheng, Yujie; Zhou, Bo; Lu, Chen; Yang, Chao

    2017-05-25

    Fault diagnosis for rolling bearings has attracted increasing attention in recent years. However, few studies have focused on fault diagnosis for rolling bearings under variable conditions. This paper introduces a fault diagnosis method for rolling bearings under variable conditions based on visual cognition. The proposed method includes the following steps. First, the vibration signal data are transformed into a recurrence plot (RP), which is a two-dimensional image. Then, inspired by the visual invariance characteristic of the human visual system (HVS), we utilize speed up robust feature to extract fault features from the two-dimensional RP and generate a 64-dimensional feature vector, which is invariant to image translation, rotation, scaling variation, etc. Third, based on the manifold perception characteristic of HVS, isometric mapping, a manifold learning method that can reflect the intrinsic manifold embedded in the high-dimensional space, is employed to obtain a low-dimensional feature vector. Finally, a classical classification method, support vector machine, is utilized to realize fault diagnosis. Verification data were collected from Case Western Reserve University Bearing Data Center, and the experimental result indicates that the proposed fault diagnosis method based on visual cognition is highly effective for rolling bearings under variable conditions, thus providing a promising approach from the cognitive computing field.

  11. Robust Machine Learning Variable Importance Analyses of Medical Conditions for Health Care Spending.

    Science.gov (United States)

    Rose, Sherri

    2018-03-11

    To propose nonparametric double robust machine learning in variable importance analyses of medical conditions for health spending. 2011-2012 Truven MarketScan database. I evaluate how much more, on average, commercially insured enrollees with each of 26 of the most prevalent medical conditions cost per year after controlling for demographics and other medical conditions. This is accomplished within the nonparametric targeted learning framework, which incorporates ensemble machine learning. Previous literature studying the impact of medical conditions on health care spending has almost exclusively focused on parametric risk adjustment; thus, I compare my approach to parametric regression. My results demonstrate that multiple sclerosis, congestive heart failure, severe cancers, major depression and bipolar disorders, and chronic hepatitis are the most costly medical conditions on average per individual. These findings differed from those obtained using parametric regression. The literature may be underestimating the spending contributions of several medical conditions, which is a potentially critical oversight. If current methods are not capturing the true incremental effect of medical conditions, undesirable incentives related to care may remain. Further work is needed to directly study these issues in the context of federal formulas. © Health Research and Educational Trust.

  12. Comparison of winter wheat yield sensitivity to climate variables under irrigated and rain-fed conditions

    Science.gov (United States)

    Xiao, Dengpan; Shen, Yanjun; Zhang, He; Moiwo, Juana P.; Qi, Yongqing; Wang, Rende; Pei, Hongwei; Zhang, Yucui; Shen, Huitao

    2016-09-01

    Crop simulation models provide alternative, less time-consuming, and cost-effective means of determining the sensitivity of crop yield to climate change. In this study, two dynamic mechanistic models, CERES (Crop Environment Resource Synthesis) and APSIM (Agricultural Production Systems Simulator), were used to simulate the yield of wheat ( Triticum aestivum L.) under well irrigated (CFG) and rain-fed (YY) conditions in relation to different climate variables in the North China Plain (NCP). The study tested winter wheat yield sensitivity to different levels of temperature, radiation, precipitation, and atmospheric carbon dioxide (CO2) concentration under CFG and YY conditions at Luancheng Agro-ecosystem Experimental Stations in the NCP. The results from the CERES and APSIM wheat crop models were largely consistent and suggested that changes in climate variables influenced wheat grain yield in the NCP. There was also significant variation in the sensitivity of winter wheat yield to climate variables under different water (CFG and YY) conditions. While a temperature increase of 2°C was the threshold beyond which temperature negatively influenced wheat yield under CFG, a temperature rise exceeding 1°C decreased winter wheat grain yield under YY. A decrease in solar radiation decreased wheat grain yield under both CFG and YY conditions. Although the sensitivity of winter wheat yield to precipitation was small under the CFG, yield decreased significantly with decreasing precipitation under the rainfed YY treatment. The results also suggest that wheat yield under CFG linearly increased by ≈3.5% per 60 ppm (parts per million) increase in CO2 concentration from 380 to 560 ppm, and yield under YY increased linearly by ≈7.0% for the same increase in CO2 concentration.

  13. Global assessment of surfing conditions: seasonal, interannual and long-term variability

    Science.gov (United States)

    Espejo, A.; Losada, I.; Mendez, F.

    2012-12-01

    International surfing destinations owe a great debt to specific combinations of wind-wave, thermal conditions and local bathymetry. As surf quality depends on a vast number of geophysical variables, a multivariable standardized index on the basis of expert judgment is proposed to analyze surf resource in a worldwide domain. Data needed is obtained by combining several datasets (reanalyses): 60-year satellite-calibrated spectral wave hindcast (GOW, WaveWatchIII), wind fields from NCEP/NCAR, global sea surface temperature from ERSST.v3b, and global tides from TPXO7.1. A summary of the global surf resource is presented, which highlights the high degree of variability in surfable events. According to general atmospheric circulation, results show that west facing low to middle latitude coasts are more suitable for surfing, especially those in Southern Hemisphere. Month to month analysis reveals strong seasonal changes in the occurrence of surfable events, enhancing those in North Atlantic or North Pacific. Interannual variability is investigated by comparing occurrence values with global and regional climate patterns showing a great influence at both, global and regional scales. Analysis of long term trends shows an increase in the probability of surfable events over the west facing coasts on the planet (i.e. + 30 hours/year in California). The resulting maps provide useful information for surfers and surf related stakeholders, coastal planning, education, and basic research.; Figure 1. Global distribution of medium quality (a) and high quality surf conditions probability (b).

  14. Condition Monitoring for Roller Bearings of Wind Turbines Based on Health Evaluation under Variable Operating States

    Directory of Open Access Journals (Sweden)

    Lei Fu

    2017-10-01

    Full Text Available Condition monitoring (CM is used to assess the health status of wind turbines (WT by detecting turbine failure and predicting maintenance needs. However, fluctuating operating conditions cause variations in monitored features, therefore increasing the difficulty of CM, for example, the frequency-domain analysis may lead to an inaccurate or even incorrect prediction when evaluating the health of the WT components. In light of this challenge, this paper proposed a method for the health evaluation of WT components based on vibration signals. The proposed approach aimed to reduce the evaluation error caused by the impact of the variable operating condition. First, the vibration signal was decomposed into a set of sub-signals using variational mode decomposition (VMD. Next, the sub-signal energy and the probability distribution were obtained and normalized. Finally, the concept of entropy was introduced to evaluate the health condition of a monitored object to provide an effective guide for maintenance. In particular, the health evaluation for CM was based on a performance review over a range of operating conditions, rather than at a certain single operating condition. Experimental investigations were performed which verified the efficiency of the evaluation method, as well as a comparison with the previous method.

  15. The cross wavelet analysis of dengue fever variability influenced by meteorological conditions

    Science.gov (United States)

    Lin, Yuan-Chien; Yu, Hwa-Lung; Lee, Chieh-Han

    2015-04-01

    The multiyear variation of meteorological conditions induced by climate change causes the changing diffusion pattern of infectious disease and serious epidemic situation. Among them, dengue fever is one of the most serious vector-borne diseases distributed in tropical and sub-tropical regions. Dengue virus is transmitted by several species of mosquito and causing lots amount of human deaths every year around the world. The objective of this study is to investigate the impact of meteorological variables to the temporal variation of dengue fever epidemic in southern Taiwan. Several extreme and average indices of meteorological variables, i.e. temperature and humidity, were used for this analysis, including averaged, maximum and minimum temperature, and average rainfall, maximum 1-hr rainfall, and maximum 24-hr rainfall. This study plans to identify and quantify the nonlinear relationship of meteorological variables and dengue fever epidemic, finding the non-stationary time-frequency relationship and phase lag effects of those time series from 1998-2011 by using cross wavelet method. Results show that meteorological variables all have a significant time-frequency correlation region to dengue fever epidemic in frequency about one year (52 weeks). The associated phases can range from 0 to 90 degrees (0-13 weeks lag from meteorological factors to dengue incidences). Keywords: dengue fever, cross wavelet analysis, meteorological factor

  16. Diurnal variability of inner-shelf circulation in the lee of a cape under upwelling conditions

    Science.gov (United States)

    Lamas, L.; Peliz, A.; Dias, J.; Oliveira, P. B.; Angélico, M. M.; Castro, J. J.; Fernandes, J. N.; Trindade, A.; Cruz, T.

    2017-07-01

    The nearshore circulation in the lee of a cape under upwelling conditions was studied using in-situ data from 3 consecutive summers (2006-2008). Focus was given to a period between 20 July and 04 August 2006 to study the diurnal variability of the cross-shelf circulation. This period was chosen because it had a steady upwelling-favourable wind condition modulated by a diurnal cycle much similar to sea breeze. The daily variability of the observed cross-shelf circulation consisted of three distinct periods: a morning period with a 3-layer vertical structure with onshore velocities at mid-depth, a mid-day period where the flow is reversed and has a 2-layer structure with onshore velocities at the surface and offshore flow below, and, lastly, in the evening, a 2-layer period with intensified offshore velocities at the surface and onshore flow at the bottom. The observed cross-shelf circulation showed a peculiar vertical shape and diurnal variability different from several other systems described in literature. We hypothesize that the flow reversal of the cross-shelf circulation results as a response to the rapid change of the wind magnitude and direction at mid-day with the presence of the cape north of the mooring site influencing this response. A numerical modelling experiment exclusively forced by winds simulated successfully most of the circulation at the ADCP site, especially the mid-day reversal and the evening's upwelling-type structure. This supports the hypothesis that the cross-shelf circulation at diurnal timescales is mostly wind-driven. By analysing the 3D circulation in the vicinity of Cape Sines we came to the conclusion that the diurnal variability of the wind and the flow interaction with topography are responsible for the circulation variability at the ADCP site, though only a small region in the south of the cape showed a similar diurnal variability. The fact that the wind diurnally undergoes relaxation and intensification strongly affects the

  17. Necessity of Initial Dilution for Sea Outfall Diffusers in Respect to the European Directive on Municipal Discharges

    DEFF Research Database (Denmark)

    Larsen, Torben

    2000-01-01

    The European Directive on municipal discharges prescribes that discharges of sewage to the sea should at least be treated biologically. The author claims that this treatment is an argument for reducing the requirement for initial dilution for sea outfall diffusers. By reducing the costs...

  18. In-situ Kd values and geochemical behavior for inorganic and organic constituents of concern at the TNX Outfall Delta

    International Nuclear Information System (INIS)

    Kaplan, D.I.

    2000-01-01

    A series of tests were conducted to provide site-specific Kd values for constituents of concern at the TNX Outfall Delta Operable Unit. These Kd values can be used to calculate contaminant migration within the operable unit and are, at this time considered to be the most defensible values

  19. Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil)

    International Nuclear Information System (INIS)

    Roth, F.; Lessa, G.C.; Wild, C.; Kikuchi, R.K.P.; Naumann, M.S.

    2016-01-01

    Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ 13 C org and δ 15 N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6 km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality. - Highlights: •Pollution by untreated sewage discharge is evident at the outfall and in Salvador's coastal zone. •Seasonal wind- and tide-driven surface currents control advective transport of discharged sewage. •Water quality at Salvador's recreational beaches is impacted by a plume of untreated sewage.

  20. Results of toxicity tests and chemical analyses conducted on sediments collected from the TNX Outfall Delta Operable Unit, July 1999

    International Nuclear Information System (INIS)

    Specht, W.L.

    2000-01-01

    In order to provide unit specific toxicity data that will be used to address critical uncertainty in the ecological risk assessment (ERA) for the TNX Outfall Delta Operable Unit (TNXOD OU), sediments were collected from eight locations in the Inner Swamp portion of the operable unit and two unit specific background locations. These samples were analyzed for total mercury, total uranium, and sediment toxicity

  1. Feedback linearization based control of a variable air volume air conditioning system for cooling applications.

    Science.gov (United States)

    Thosar, Archana; Patra, Amit; Bhattacharyya, Souvik

    2008-07-01

    Design of a nonlinear control system for a Variable Air Volume Air Conditioning (VAVAC) plant through feedback linearization is presented in this article. VAVAC systems attempt to reduce building energy consumption while maintaining the primary role of air conditioning. The temperature of the space is maintained at a constant level by establishing a balance between the cooling load generated in the space and the air supply delivered to meet the load. The dynamic model of a VAVAC plant is derived and formulated as a MIMO bilinear system. Feedback linearization is applied for decoupling and linearization of the nonlinear model. Simulation results for a laboratory scale plant are presented to demonstrate the potential of keeping comfort and maintaining energy optimal performance by this methodology. Results obtained with a conventional PI controller and a feedback linearizing controller are compared and the superiority of the proposed approach is clearly established.

  2. Identification of voltage stability condition of a power system using measurements of bus variables

    Directory of Open Access Journals (Sweden)

    Durlav Hazarika

    2014-12-01

    Full Text Available Several online methods were proposed for investigating the voltage stability condition of an interconnected power system using the measurements of voltage and current phasors at a bus. For this purpose, phasor measurement units (PMUs are used. A PMU is a device which measures the electrical waves on an electrical network, using a common time source (reference bus for synchronisation. This study proposes a method for online monitoring of voltage stability condition of a power system using measurements of bus variables namely – (i real power, (ii reactive power and (iii bus voltage magnitude at a bus. The measurements of real power, reactive power and bus voltage magnitude could be extracted/captured from a smart energy meter. The financial involvement for implementation of the proposed method would significantly lower compared with the PMU-based method.

  3. Effects of dual-task conditions on cervical spine movement variability.

    Science.gov (United States)

    Niederer, Daniel; Vogt, Lutz; Vogel, Johanna; Banzer, Winfried

    2017-09-22

    The potential to accurately perform cervical movements during more challenging tasks might be of importance to prevent dysfunctional motion characteristics. Although sensorimotor function during dual-task conditions are of increasing interest in biomedical and rehabilitation research, effects of such conditions on movement consistency of the neck have not yet been investigated. In this crossover MiSpEx(Medicine in Spine Exercise)-diagnostic study, we aimed to explore differences between single and dual-task conditions on cervical movement variability. Nineteen healthy participants (9 male; 24.5 ± 3.3 y) performed 10 repetitive maximal cervical movements in (1) flexion/extension and (2) lateral flexion, during one single- and during two dual-task test conditions (cognitive, motor) in a randomised and cross-over sequence. Latter consisted of a working memory n-back task (n= 2) and a repetitive ankle movement task. Range of motion (RoM) was assessed using an external three-dimensional ultrasonic movement analysis system. Coefficient of variation (CV) for repetitive RoM was analysed for differences between conditions and controlled for variances in intra-individual movement characteristics. Friedman and post-hoc Bonferroni-adjusted confidence intervals for differences from single- to dual-task values revealed changes in CV in flexion/extension from single-task to motor dual-task (+0.02 ± 0.02 (97.5%CI: 0.01; 0.03); pdual-task condition (+0.01 ± 0.02 (97.5%CI: 0.003; 0.02)) nor for lateral flexion (p> 0.05). Pearson regression analyses revealed a linear negative (pdual-task (R=2 0.55). Results for lateral flexion are comparable, baseline CV negatively impacts differences to cognitive (R=2 0.2) and motor dual-task performance (R=2 0.76; pdual-task conditions while participants with a higher variability remained almost stable or showed a decrease. The results point toward a complex interrelationship of motion patterns and adaptation processes during challenging tasks

  4. The XRF spectrometer and the selection of analysis conditions (instrumental variables)

    International Nuclear Information System (INIS)

    Willis, J.P.

    2002-01-01

    Full text: This presentation will begin with a brief discussion of EDXRF and flat- and curved-crystal WDXRF spectrometers, contrasting the major differences between the three types. The remainder of the presentation will contain a detailed overview of the choice and settings of the many instrumental variables contained in a modern WDXRF spectrometer, and will discuss critically the choices facing the analyst in setting up a WDXRF spectrometer for different elements and applications. In particular it will discuss the choice of tube target (when a choice is possible), the kV and mA settings, tube filters, collimator masks, collimators, analyzing crystals, secondary collimators, detectors, pulse height selection, X-ray path medium (air, nitrogen, vacuum or helium), counting times for peak and background positions and their effect on counting statistics and lower limit of detection (LLD). The use of Figure of Merit (FOM) calculations to objectively choose the best combination of instrumental variables also will be discussed. This presentation will be followed by a shorter session on a subsequent day entitled - A Selection of XRF Conditions - Practical Session, where participants will be given the opportunity to discuss in groups the selection of the best instrumental variables for three very diverse applications. Copyright (2002) Australian X-ray Analytical Association Inc

  5. Proposed experiment for SnCl2 treatment of Outfall 200 for the purpose of mercury removal from East Fork Poplar Creek, Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Southworth, G.R.

    1997-03-01

    Identification and treatment/elimination of point sources of mercury (Hg) to East Fork Poplar Creek (EFPC) within the Y-12 Plant have reduced base flow mercury concentrations considerably; but, after all such actions are completed, nonpoint sources will continue to add mercury to the creek. Studies conducted in 1996 on the use of air stripping to remove elemental mercury from Outfall 51, a mercury-contaminated natural spring, demonstrated that the addition of trace concentrations of stannous chloride (SnCl 2 ) converted a large fraction of the dissolved mercury in the outfall to elemental mercury, which could subsequently be removed by air stripping. Dissolved mercury is the dominant form in EFPC at the north/south (N/S) pipes, where it emerges from the underground storm drain network. More than 50% of that mercury is capable of being rapidly reduced by the addition of a 3--5 fold molar excess of stannous chloride. Upon conversion to the volatile gaseous (elemental) form, mercury would be lost across the air-water interface through natural volatilization. EFPC within the Y-12 Plant is shallow, turbulent, and open to sunlight and wind, providing conditions that facilitate natural evasion of volatile chemicals from the water. Preliminary calculations estimate that 75% or more of the elemental mercury could be removed via evasion between the N/S pipes and the Y-l2 Plant boundary (Station 17). Alternatively, elemental mercury might be removed from EFPC in a short reach of stream below the N/S pipes by an in-situ air stripping system which bubbles air through the water column. The purpose of these proposed experiments is to test whether natural volatilization or in-situ air stripping may be used to further reduce baseflow concentrations of mercury in EFPC. Results of this experiment will be useful for understanding the transport and fate of other volatile chemicals in the upper reaches of EFPC

  6. Rainfall Downscaling Conditional on Upper-air Variables: Assessing Rainfall Statistics in a Changing Climate

    Science.gov (United States)

    Langousis, Andreas; Deidda, Roberto; Marrocu, Marino; Kaleris, Vassilios

    2014-05-01

    Due to its intermittent and highly variable character, and the modeling parameterizations used, precipitation is one of the least well reproduced hydrologic variables by both Global Climate Models (GCMs) and Regional Climate Models (RCMs). This is especially the case at a regional level (where hydrologic risks are assessed) and at small temporal scales (e.g. daily) used to run hydrologic models. In an effort to remedy those shortcomings and assess the effect of climate change on rainfall statistics at hydrologically relevant scales, Langousis and Kaleris (2013) developed a statistical framework for simulation of daily rainfall intensities conditional on upper air variables. The developed downscaling scheme was tested using atmospheric data from the ERA-Interim archive (http://www.ecmwf.int/research/era/do/get/index), and daily rainfall measurements from western Greece, and was proved capable of reproducing several statistical properties of actual rainfall records, at both annual and seasonal levels. This was done solely by conditioning rainfall simulation on a vector of atmospheric predictors, properly selected to reflect the relative influence of upper-air variables on ground-level rainfall statistics. In this study, we apply the developed framework for conditional rainfall simulation using atmospheric data from different GCM/RCM combinations. This is done using atmospheric data from the ENSEMBLES project (http://ensembleseu.metoffice.com), and daily rainfall measurements for an intermediate-sized catchment in Italy; i.e. the Flumendosa catchment. Since GCM/RCM products are suited to reproduce the local climatology in a statistical sense (i.e. in terms of relative frequencies), rather than ensuring a one-to-one temporal correspondence between observed and simulated fields (i.e. as is the case for ERA-interim reanalysis data), we proceed in three steps: a) we use statistical tools to establish a linkage between ERA-Interim upper-air atmospheric forecasts and

  7. A hybrid approach to fault diagnosis of roller bearings under variable speed conditions

    Science.gov (United States)

    Wang, Yanxue; Yang, Lin; Xiang, Jiawei; Yang, Jianwei; He, Shuilong

    2017-12-01

    Rolling element bearings are one of the main elements in rotating machines, whose failure may lead to a fatal breakdown and significant economic losses. Conventional vibration-based diagnostic methods are based on the stationary assumption, thus they are not applicable to the diagnosis of bearings working under varying speeds. This constraint limits the bearing diagnosis to the industrial application significantly. A hybrid approach to fault diagnosis of roller bearings under variable speed conditions is proposed in this work, based on computed order tracking (COT) and variational mode decomposition (VMD)-based time frequency representation (VTFR). COT is utilized to resample the non-stationary vibration signal in the angular domain, while VMD is used to decompose the resampled signal into a number of band-limited intrinsic mode functions (BLIMFs). A VTFR is then constructed based on the estimated instantaneous frequency and instantaneous amplitude of each BLIMF. Moreover, the Gini index and time-frequency kurtosis are both proposed to quantitatively measure the sparsity and concentration measurement of time-frequency representation, respectively. The effectiveness of the VTFR for extracting nonlinear components has been verified by a bat signal. Results of this numerical simulation also show the sparsity and concentration of the VTFR are better than those of short-time Fourier transform, continuous wavelet transform, Hilbert-Huang transform and Wigner-Ville distribution techniques. Several experimental results have further demonstrated that the proposed method can well detect bearing faults under variable speed conditions.

  8. A New Fault Diagnosis Algorithm for PMSG Wind Turbine Power Converters under Variable Wind Speed Conditions

    Directory of Open Access Journals (Sweden)

    Yingning Qiu

    2016-07-01

    Full Text Available Although Permanent Magnet Synchronous Generator (PMSG wind turbines (WTs mitigate gearbox impacts, they requires high reliability of generators and converters. Statistical analysis shows that the failure rate of direct-drive PMSG wind turbines’ generators and inverters are high. Intelligent fault diagnosis algorithms to detect inverters faults is a premise for the condition monitoring system aimed at improving wind turbines’ reliability and availability. The influences of random wind speed and diversified control strategies lead to challenges for developing intelligent fault diagnosis algorithms for converters. This paper studies open-circuit fault features of wind turbine converters in variable wind speed situations through systematic simulation and experiment. A new fault diagnosis algorithm named Wind Speed Based Normalized Current Trajectory is proposed and used to accurately detect and locate faulted IGBT in the circuit arms. It is compared to direct current monitoring and current vector trajectory pattern approaches. The results show that the proposed method has advantages in the accuracy of fault diagnosis and has superior anti-noise capability in variable wind speed situations. The impact of the control strategy is also identified. Experimental results demonstrate its applicability on practical WT condition monitoring system which is used to improve wind turbine reliability and reduce their maintenance cost.

  9. Thermogravimetric study of a Phase Change Slurry: Effect of variable conditions

    International Nuclear Information System (INIS)

    Giro-Paloma, J.; Valle-Zermeño, R. del; Fernández, A.I.; Chimenos, J.M.; Formosa, J.

    2016-01-01

    Highlights: • Dry or wet PCS present differences in their thermal behavior. • The optimum conditions of dry PCS were determined by TGA. • Type of atmosphere and heating rate were the variables under consideration. • T peak can be accurately determined at 1 °C·min −1 in N 2. • Fusion/latent heat can be best determined at 10 °C·min −1 . - Abstract: Microcapsules containing Phase Change Materials (MPCM) are widely used for passive systems in energy storage. When MPCM are mixed with a carrier fluid, Phase Change Slurries (PCS) are used for heat transfer fluids in active systems or heat transport systems. The thermal behavior of PCS can be measured as dry or wet basis, resulting in important differences in weight losses. This study explores the optimum conditions for analyzing the thermal behavior of dried PCS by thermogravimetric analysis (TGA) varying the parameter conditions for obtaining peak temperature and heat flow (latent heat). The factors that were taken into account were the atmosphere of study (air and nitrogen) and the heating rate (0.5, 1, 5, and 10 °C·min −1 ). The best conditions to determine peak temperature are at 1 °C·min −1 and in N 2 atmosphere, whereas the decomposition fusion/latent heat of the sample is improved at higher heating velocities towards 10 °C·min −1 .

  10. Seawater quality and microbial communities at a desalination plant marine outfall. A field study at the Israeli Mediterranean coast.

    Science.gov (United States)

    Drami, Dror; Yacobi, Yosef Z; Stambler, Noga; Kress, Nurit

    2011-11-01

    Global desalination quadrupled in the last 15 years and the relative importance of seawater desalination by reverse osmosis (SWRO) increased as well. While the technological aspects of SWRO plants are extensively described, studies on the environmental impact of brine discharge are lacking, in particular in situ marine environmental studies. The Ashqelon SWRO plant (333,000 m(3) d(-1) freshwater) discharges brine and backwash of the pre-treatment filters (containing ferric hydroxide coagulant) at the seashore, next to the cooling waters of a power plant. At the time of this study brine and cooling waters were discharged continuously and the backwash discharge was pulsed, with a frequency dependent on water quality at the intake. The effects of the discharges on water quality and neritic microbial community were identified, quantified and attributed to the different discharges. The mixed brine-cooling waters discharge increased salinity and temperature at the outfall, were positively buoyant, and dispersed at the surface up to 1340 m south of the outfall. Nutrient concentrations were higher at the outfall while phytoplankton densities were lower. Chlorophyll-a and picophytoplankton cell numbers were negatively correlated with salinity, but more significantly with temperature probably as a result of thermal pollution. The discharge of the pulsed backwash increased turbidity, suspended particulate matter and particulate iron and decreased phytoplankton growth efficiency at the outfall, effects that declined with distance from the outfall. The discharges clearly reduced primary production but we could not attribute the effect to a specific component of the discharge. Bacterial production was also affected but differently in the three surveys. The combined and possible synergistic effects of SWRO desalination along the Israeli shoreline should be taken into account when the three existing plants and additional ones are expected to produce 2 Mm(3) d(-1) freshwater by

  11. Measurement and evaluation of thermal effects in the intermixing zone at low power nuclear station outfall

    International Nuclear Information System (INIS)

    Kamath, P.R.; Gurg, R.P.; Bhat, I.S.; Vyas, P.V.

    1978-01-01

    Observations and evaluations of thermal effects in the lake near the RAPS-1 REACTOR, are reported. The coolant waters are drawn from the lake at a depth of 8-10 m below the surface and discharged through an open channel with a temperature rise of 10deg C. Temperature profiles and spread in the velocity of the outfall are mapped using in situ monitors. These studies show evidence of thermal stratification in the period following winter and the existence of a well established thermocline. Parasitism and eutrophication are also observed. The thermal effects are found to be accentuated by photosynthetic effects. Proposal to utilise waste heat for algal culture in the Kalpakkam nuclear site in South and mariculture (lobsters, prawns) in the heated effluents canal at the Tarapur Atomic Power Station near Bombay are discussed. (K.B.)

  12. Development in cooling water intake and outfall systems for atomic or steam power stations

    International Nuclear Information System (INIS)

    Wada, Akira

    1987-01-01

    The condenser cooling water channel, in its functional aspects, is an important structure for securing a stable supply of cooling water. In its design it is necessary to give a thorough-going study to a reduction of ranges affected by discharged warm water and minimizing the effect of discharged water on navigating ships, and in its functional aspects as a structure for power generation, avoiding the recirculation of discharged warm water as well as to maintaining the operation of power stations in case of abnormalities (concentration of dirts owing to typhoons and floods, outbreak of a large amount of jellyfishes, etc.), and all these aspects must be reflected in the design of cooling water channel systems. In this paper, the present situation relating to the design of cooling water intake and outfall systems in Japan is discussed. (author). 10 figs

  13. Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

    Science.gov (United States)

    Abessa, D.M.S.; Carr, R.S.; Rachid, B.R.F.; Sousa, E.C.P.M.; Hortelani, M.A.; Sarkis, J.E.

    2005-01-01

    The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the “Threshold Effect Level” values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted.

  14. Proof-of-Concept of the Phytoimmobilization Technology for TNX Outfall Delta: Final Report; FINAL

    International Nuclear Information System (INIS)

    Kaplan, D.I.

    2001-01-01

    A series of proof-of-principle studies was initiated to evaluate the soil remediation technology, phytoimmobilization, for application at the TNX Outfall Delta (TNX OD) operable unit. Phytoimmobilization involves two steps. The first step is entitled phytoextraction, and it takes place mostly during the spring and summer. During this step the plants extract contaminants from the sediment into the roots and then translocate the contaminants to the aboveground plant parts. The second step is referred to as sequestration and it takes place largely during the autumn and winter when annual plants senesce or deciduous trees drop their leaves. This step involves the immobilization of the contaminant once it leaches form the fallen leaves into a ''geomat,'' a geotextile embedded with mineral sequestering agents. This final report describes the results to date, including those reported in the status report (Kaplan et al. 2000a), those completed since the report was issued, and the preliminary calculations of the phytoimmobilization effectiveness

  15. Intakes and outfalls for seawater reverse-osmosis desalination facilities innovations and environmental impacts

    CERN Document Server

    Jones, Burton; Maliva, Robert

    2015-01-01

    The book assembles the latest research on new design techniques in water supplies using desalinated seawater. The authors examine the diverse issues related to the intakes and outfalls of these facilities. They clarify how and why these key components of the facilities impact the cost of operation and subsequently the cost of water supplied to the consumers. The book consists of contributed articles from a number of experts in the field who presented their findings at the “Desalination Intakes and Outfalls” workshop held at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia in October, 2013. The book integrates coverage relevant to a wide variety of researchers and professionals in the general fields of environmental engineering and sustainable development.

  16. PBDE and PCB accumulation in benthos near marine wastewater outfalls: The role of sediment organic carbon

    International Nuclear Information System (INIS)

    Dinn, Pamela M.; Johannessen, Sophia C.; Ross, Peter S.; Macdonald, Robie W.; Whiticar, Michael J.; Lowe, Christopher J.; Roodselaar, Albert van

    2012-01-01

    Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in sediments and benthic invertebrates near submarine municipal outfalls in Victoria and Vancouver, B.C., Canada, two areas with contrasting receiving environments. PBDE concentrations in wastewater exceeded those of the legacy PCBs by eight times at Vancouver and 35 times at Victoria. Total PBDE concentrations in benthic invertebrates were higher near Vancouver than Victoria, despite lower concentrations in sediments, and correlated with organic carbon-normalized concentrations in sediment. Principal Components Analysis indicated uptake of individual PBDE congeners was determined by sediment properties (organic carbon, grain size), while PCB congener uptake was governed by physico-chemical properties (octanol-water partitioning coefficient). Results suggest the utility of sediment quality guidelines for PBDEs and likely PCBs benefit if based on organic carbon-normalized concentrations. Also, where enhanced wastewater treatment increases the PBDEs to particulate organic carbon ratio in effluent, nearfield benthic invertebrates may face increased PBDE accumulation. - Highlights: ► Physical receiving environment affects PBDE bioaccumulation by benthic invertebrates. ► PBDE uptake is correlated with organic-carbon normalized sediment concentrations. ► PBDE and PCB congener uptake are governed by different properties. ► PBDE sediment quality guidelines may benefit by using organic carbon-normalized data. ► Enhanced wastewater treatment may mean increased benthic invertebrate PBDE bioaccumulation. - The physical receiving environment affects the accumulation of PBDEs by benthic invertebrates near submarine municipal outfalls, and uptake of PBDE congeners is governed by different properties than for PCB congeners.

  17. The tradeoff between signal detection and recognition rules auditory sensitivity under variable background noise conditions.

    Science.gov (United States)

    Lugli, Marco

    2015-12-07

    Animal acoustic communication commonly takes place under masked conditions. For instance, sound signals relevant for mating and survival are very often masked by background noise, which makes their detection and recognition by organisms difficult. Ambient noise (AN) varies in level and shape among different habitats, but also remarkable variations in time and space occurs within the same habitat. Variable AN conditions mask hearing thresholds of the receiver in complex and unpredictable ways, thereby causing distortions in sound perception. When communication takes place in a noisy environment, a highly sensitive system might confer no advantage to the receiver compared to a less sensitive one. The effects of noise masking on auditory thresholds and hearing-related functions are well known, and the potential role of AN in the evolution of the species' auditory sensitivity has been recognized by few authors. The mechanism of the underlying selection process has never been explored, however. Here I present a simple fitness model that seeks for the best sensitivity of a hearing system performing the detection and recognition of the sound under variable AN conditions. The model predicts higher sensitivity (i.e. lower hearing thresholds) as best strategy for species living in quiet habitats and lower sensitivity (i.e. higher hearing thresholds) as best strategy for those living in noisy habitats provided the cost of incorrect recognition is not low. The tradeoff between detection and recognition of acoustic signals appears to be a key factor determining the best level of hearing sensitivity of a species when acoustic communication is corrupted by noise. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  19. Understanding Hydrological Processes in Variable Source Areas in the Glaciated Northeastern US Watersheds under Variable Climate Conditions

    Science.gov (United States)

    Steenhuis, T. S.; Azzaino, Z.; Hoang, L.; Pacenka, S.; Worqlul, A. W.; Mukundan, R.; Stoof, C.; Owens, E. M.; Richards, B. K.

    2017-12-01

    The New York City source watersheds in the Catskill Mountains' humid, temperate climate has long-term hydrological and water quality monitoring data It is one of the few catchments where implementation of source and landscape management practices has led to decreased phosphorus concentration in the receiving surface waters. One of the reasons is that landscape measures correctly targeted the saturated variable source runoff areas (VSA) in the valley bottoms as the location where most of the runoff and other nonpoint pollutants originated. Measures targeting these areas were instrumental in lowering phosphorus concentration. Further improvements in water quality can be made based on a better understanding of the flow processes and water table fluctuations in the VSA. For that reason, we instrumented a self-contained upland variable source watershed with a landscape characteristic of a soil underlain by glacial till at shallow depth similar to the Catskill watersheds. In this presentation, we will discuss our experimental findings and present a mathematical model. Variable source areas have a small slope making gravity the driving force for the flow, greatly simplifying the simulation of the flow processes. The experimental data and the model simulations agreed for both outflow and water table fluctuations. We found that while the flows to the outlet were similar throughout the year, the discharge of the VSA varies greatly. This was due to transpiration by the plants which became active when soil temperatures were above 10oC. We found that shortly after the temperature increased above 10oC the baseflow stopped and only surface runoff occurred when rainstorms exceeded the storage capacity of the soil in at least a portion of the variable source area. Since plant growth in the variable source area was a major variable determining the base flow behavior, changes in temperature in the future - affecting the duration of the growing season - will affect baseflow and

  20. Instability of automotive air conditioning system with a variable displacement compressor. Part 1. Experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Changqing; Dou, Chunpeng; Yang, Xinjiang; Li, Xianting [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (People' s Republic of China)

    2005-11-01

    A test system is built first in order to investigate the instability of the automotive air conditioning (AAC) system with a variable displacement compressor (VDC), and hunting phenomena caused by the large external disturbance in the AAC system with a VDC and a thermal expansion valve, and in the AAC system with a VDC and a fixed-area throttling device are investigated experimentally in part 1 of this paper. The experimental results indicate that there also exist the hunting phenomena in the AAC system with a fixed-area throttling device. The system stability is found to be dependent on the direction of the external disturbance, and the system is apt to cause hunting when the condensing pressure decreases excessively since it may cause two-phase state at the throttling device inlet and make a large disturbance to the system. The piston stroke length will oscillate only when the oscillation amplitudes of forces acting on the wobble plate are great enough, otherwise the piston stroke length will be kept invariable, and then the system instability rule is also suitable for the AAC system with a fixed displacement compressor. From the experimental results, it is concluded that the two-phase flow at the throttling device inlet or at the evaporator outlet is the necessary condition but not sufficient condition for system hunting. Finally, a new concept, conservative stable region, is proposed based on the experimental results and theoretical analysis. (author)

  1. Extracting Archaeological Feautres from GPR Surveys Conducted with Variable Soil Moisture Conditions

    Science.gov (United States)

    Morris, I. M.; Glisic, B.; Gonciar, A.

    2017-12-01

    As a common tool for subsurface archaeological prospection, ground penetrating radar (GPR) is a useful method for increasing the efficiency of archaeological excavations. Archaeological sites are often temporally and financially constrained, therefore having limited ability to reschedule surveys compromised by weather. Furthermore, electromagnetic GPR surveys are especially sensitive to variations in water content, soil type, and site-specific interference. In this work, GPR scans of a partially excavated Roman villa consisting of different construction materials and phases (limestone, andesite, brick) in central Romania are compared. Surveys were conducted with a 500 MHz GPR antenna in both dry (pre-rain event) and wet (post-rain event) conditions. Especially in time or depth slices, wet surveys present additional archaeological features that are not present or clear in the standard dry conditions, while simultaneously masking the clutter present in those scans. When dry, the limestone has a similar dielectric constant to the soil and does not provide enough contrast in electromagnetic properties for strong reflections despite the significant difference in their physical properties. Following precipitation, however, the electromagnetic properties of these two materials is dominated by their respective water content and the contrast is enhanced. For this reason, the wet surveys are particularly necessary for revealing reflections from the limestone features often invisible in dry surveys. GPR surveys conducted in variable environmental conditions provide unique archaeological information, with potential near-surface geophysical applications in nondestructive material characterization and identification.

  2. Topic Correlation Analysis for Bearing Fault Diagnosis Under Variable Operating Conditions

    Science.gov (United States)

    Chen, Chao; Shen, Fei; Yan, Ruqiang

    2017-05-01

    This paper presents a Topic Correlation Analysis (TCA) based approach for bearing fault diagnosis. In TCA, Joint Mixture Model (JMM), a model which adapts Probability Latent Semantic Analysis (PLSA), is constructed first. Then, JMM models the shared and domain-specific topics using “fault vocabulary” . After that, the correlations between two kinds of topics are computed and used to build a mapping matrix. Furthermore, a new shared space spanned by the shared and mapped domain-specific topics is set up where the distribution gap between different domains is reduced. Finally, a classifier is trained with mapped features which follow a different distribution and then the trained classifier is tested on target bearing data. Experimental results justify the superiority of the proposed approach over the stat-of-the-art baselines and it can diagnose bearing fault efficiently and effectively under variable operating conditions.

  3. Modeling of water and solute transport under variably saturated conditions: state of the art

    International Nuclear Information System (INIS)

    Lappala, E.G.

    1980-01-01

    This paper reviews the equations used in deterministic models of mass and energy transport in variably saturated porous media. Analytic, quasi-analytic, and numerical solution methods to the nonlinear forms of transport equations are discussed with respect to their advantages and limitations. The factors that influence the selection of a modeling method are discussed in this paper; they include the following: (1) the degree of coupling required among the equations describing the transport of liquids, gases, solutes, and energy; (2) the inclusion of an advection term in the equations; (3) the existence of sharp fronts; (4) the degree of nonlinearity and hysteresis in the transport coefficients and boundary conditions; (5) the existence of complex boundaries; and (6) the availability and reliability of data required by the models

  4. Application of Peleg's equation to describe creep responses of potatoes under constant and variable storage conditions.

    Science.gov (United States)

    Solomon, W K; Jindal, V K

    2017-06-01

    The application of Peleg's equation to characterize creep behavior of potatoes during storage was investigated. Potatoes were stored at 25, 15, 5C, and variable (fluctuating) temperature for 16 or 26 weeks. The Peleg equation adequately described the creep response of potatoes during storage at all storage conditions (R 2  = .97to .99). Peleg constant k 1 exhibited a significant (p creep responses during storage or processing will be potentially helpful to better understand the phenomenon. The model parameters from such model could be used to relate rheological properties of raw and cooked potatoes. Moreover, the model parameters could be used to establish relationship between instrumental and sensory attributes which will help in the prediction of sensory attributes from instrumental data. © 2016 Wiley Periodicals, Inc.

  5. Can contrasting environmental conditions of mangroves induce morphological variability in Aratus pisonii (Crustacea: Brachyura: Sesarmidae?

    Directory of Open Access Journals (Sweden)

    Beatriz López-Sánchez

    2016-09-01

    Full Text Available Aratus pisonii is one of the most common crab species in Neotropical mangroves. It shows great plasticity in its life history traits, which makes it an interesting subject for comparative studies. This study evaluated the morphometric variability in five populations of A. pisonii inhabiting mangroves with different degrees of structural development under contrasting environmental conditions. Mangrove forests located on the northwest coast of Venezuela were studied during the rainy season in 2006. The results showed morphometric differences and interaction between sampling sites and sex (PERMANOVA, P=0.0001, as well as the presence of five morphological groups in males and four in females. The findings support the existence of sexual dimorphism. Females from the dwarf hypersaline mangrove showed a wide variability associated with the chelipeds. The differences in crab morphology between sites seem to be related to a combination of environmental factors that is unique for each habitat, leading to the formation of different morphological groups, in which the mangrove structural development (resource availability and salinity (which compromises the energy budget play an important role. The presence of more robust chelipeds in females from the dwarf hypersaline mangrove seems to reflect an adaptation to the biomechanical properties of the leaves (sclerophylly.

  6. On thermoeconomics of energy systems at variable load conditions: Integrated optimization of plant design and operation

    International Nuclear Information System (INIS)

    Piacentino, A.; Cardona, F.

    2007-01-01

    Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process and, separately, the cost fractions related to capital depreciation (which require additional distinctions with respect to plants in steady operation) and to exergy consumption. The relevant effects of the efficiency penalty due to off design operation on the exergetic cost of internal flows are also examined. An original algorithm is proposed for the integrated optimization of plant design and operation based on an analytical solution by the Lagrange multipliers method and on a multi-objective decision function, expressed either in terms of net cash flow or primary energy saving. The method is suitable for application in complex energy systems, such as 'facilities of components of a same product' connected to external networks for power or heat distribution. For demonstrative purposes, the proposed thermoeconomically aided optimization is performed for a grid connected trigeneration system to be installed in a large hotel

  7. GENETIC VARIABILITY OF CULTURED PLANT TISSUES UNDER NORMAL CONDITIONS AND UNDER STRESS

    Directory of Open Access Journals (Sweden)

    Dolgikh Yu.I.

    2012-08-01

    Full Text Available The genetic variability induced by in vitro conditions known as somaclonal variation is of practical interest due to its potential uses in plant breeding but, on the other hand, if clonal propagation or transformation is main goal, it becomes an unwelcome phenomenon. Thus, it is important to know frequency, the genomic distribution, the mechanisms and factors influencing somaclonal variation. We studied variability of PCR-based DNA markers of cultured tissues and regenerated plants of maize and bread wheat. The original A188 line of maize and the somaclones obtained were tested using 38 RAPD and 10 ISSR primers. None of the A188 plants showed variation in the RAPD and ISSR spectra for any of the primers used. However, the PCR spectra obtained from the somaclones demonstrated some variations, i.e., 22 RAPD primers and 6 ISSR primers differentiated at least one somaclonal variant from the progenitor line. Six SCAR markers were developed based on several RAPD and ISSR fragments. The inheritance of these SCAR markers was verified in the selfing progeny of each somaclone in the R1–R4 generations and in the hybrids, with A188 as the parental line in the F1 and F2 generations. These markers were sequenced and bioinformatic searches were performed to understand the molecular events that may underlie the variability observed in the somaclones. All changes were found in noncoding sequences and were induced by different molecular events, such as the insertion of long terminal repeat transposon, precise miniature inverted repeat transposable element (MITE excision, microdeletion, recombination, and a change in the pool of mitochondrial DNA. In two groups of independently produced somaclones, the same features (morphological, molecular were variable, which confirms the theory of ‘hot spots’ occurring in the genome. The presence of the same molecular markers in the somaclones and in different non-somaclonal maize variants suggests that in some cases

  8. Resting heart rate variability predicts safety learning and fear extinction in an interoceptive fear conditioning paradigm.

    Directory of Open Access Journals (Sweden)

    Meike Pappens

    Full Text Available This study aimed to investigate whether interindividual differences in autonomic inhibitory control predict safety learning and fear extinction in an interoceptive fear conditioning paradigm. Data from a previously reported study (N = 40 were extended (N = 17 and re-analyzed to test whether healthy participants' resting heart rate variability (HRV - a proxy of cardiac vagal tone - predicts learning performance. The conditioned stimulus (CS was a slight sensation of breathlessness induced by a flow resistor, the unconditioned stimulus (US was an aversive short-lasting suffocation experience induced by a complete occlusion of the breathing circuitry. During acquisition, the paired group received 6 paired CS-US presentations; the control group received 6 explicitly unpaired CS-US presentations. In the extinction phase, both groups were exposed to 6 CS-only presentations. Measures included startle blink EMG, skin conductance responses (SCR and US-expectancy ratings. Resting HRV significantly predicted the startle blink EMG learning curves both during acquisition and extinction. In the unpaired group, higher levels of HRV at rest predicted safety learning to the CS during acquisition. In the paired group, higher levels of HRV were associated with better extinction. Our findings suggest that the strength or integrity of prefrontal inhibitory mechanisms involved in safety- and extinction learning can be indexed by HRV at rest.

  9. Variability in the organic ligands released by Emiliania huxleyi under simulated ocean acidification conditions

    Directory of Open Access Journals (Sweden)

    Guillermo Samperio-Ramos

    2017-12-01

    Full Text Available The variability in the extracellular release of organic ligands by Emiliania huxleyi under four different pCO2 scenarios (225, 350, 600 and 900 μatm, was determined. Growth in the batch cultures was promoted by enriching them only with major nutrients and low iron concentrations. No chelating agents were added to control metal speciation. During the initial (IP, exponential (EP and steady (SP phases, extracellular release rates, normalized per cell and day, of dissolved organic carbon (DOCER, phenolic compounds (PhCER, dissolved combined carbohydrates (DCCHOER and dissolved uronic acids (DUAER in the exudates were determined. The growth rate decreased in the highest CO2 treatment during the IP (<48 h, but later increased when the exposure was longer (more than 6 days. DOCER did not increase significantly with high pCO2. Although no relationship was observed between DCCHOER and the CO2 conditions, DCCHO was a substantial fraction of the freshly released organic material, accounting for 18% to 37%, in EP, and 14% to 23%, in SP, of the DOC produced. Growth of E. huxleyi induced a strong response in the PhCER and DUAER. While in EP, PhCER were no detected, the DUAER remained almost constant for all CO2 treatments. Increases in the extracellular release of these organic ligands during SP were most pronounced under high pCO2 conditions. Our results imply that, during the final growth stage of E. huxleyi, elevated CO2 conditions will increase its excretion of acid polysaccharides and phenolic compounds, which may affect the biogeochemical behavior of metals in seawater.

  10. Community Structure of Fish and Macrobenthos at Selected Sites in the Vicinity of Mokapu Ocean Outfall, Oahu, Hawaii, 1998 (NODC Accession 0000173)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report provides the results of the first quantitative survey of the coral reef communities in the vicinity of the Mokapu Ocean Outfall in Kailua Bay, Oahu,...

  11. A Survey of Selected Coral and Fish Assemblages Near the Waianae Ocean Outfall, Oahu, Hawaii, 1990-1999 (NODC Accession 0000794)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1990-1999, coral growth and fish abundance were monitored at stations located at and in the vicinity of the Waianae Ocean Outfall. Comparisons of results with...

  12. Sediment monitoring and benthic faunal sampling adjacent to the Sand Island ocean outfall, Oahu, Hawaii, 1986-2010 (NODC Accession 9900088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic fauna and sediment in the vicinity of the Sand Island ocean outfall were sampled from 1986-2010. To assess the environmental quality, sediment grain size and...

  13. Sediment Monitoring and Benthic Faunal Sampling Adjacent to the Barbers Point Ocean Outfall, Oahu, Hawaii, 1986-2010 (NODC Accession 9900098)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic fauna and sediment in the vicinity of the Barbers Point (Honouliuli) ocean outfall were sampled from 1986-2010. To assess the environmental quality, sediment...

  14. Surveys of Selected Coral and Fish Assemblages Adjacent to the Waianae Ocean Outfall, Oahu, Hawaii, 2003-2010 (NODC Accession 0084515)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Since 1990, biota of the coral reef ecosystems have been annualy monitored at stations located at and in the vicinity of the Waianae Ocean Sewage Outfall. NODC...

  15. A survey of selected coral and fish assemblages near the Waianae Ocean Outfall, Oahu, Hawaii, 1990-1999 (NODC Accession 0000794)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1990-1999, coral growth and fish abundance were monitored at stations located at and in the vicinity of the Waianae Ocean Outfall. Comparisons of results with...

  16. Community Structure of Fish and Macrobenthos at Selected Shallow-water Sites in Relation to the Barber's Point Outfall, Oahu, Hawaii, 1991 - 1999 (NODC Accession 0000174)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report provides the results of the eight years of an annual quantitative monitoring of shallow marine communities inshore of the Barbers Point Ocean Outfall...

  17. Remaining Sites Verification Package for the 116-F-16, PNL Outfall and the 100-F-43, PNL Outfall Spillway. Attachment to Waste Site Reclassification Form 2006-039 and 2006-096

    International Nuclear Information System (INIS)

    Dittmer, L.M.

    2006-01-01

    The 116-F-16 waste site is the former Pacific National Laboratories (PNL) Outfall, used to discharge waste effluents from the 100-F Experimental Animal Farm. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  18. Study on variability of temperature and precipitation conditions in the South Eastern Bulgaria

    International Nuclear Information System (INIS)

    Koleva-Lizama, Ivanka; Lizama Rivas, Bernardo

    2004-01-01

    Freshwater resources are an essential component of the earth's hydrosphere and an indispensable part of all terrestrial ecosystems. The freshwater environment is characterized by the hydrological cycle. Global climate change and pollution could also have an impact on freshwater resources and their availability. There is now sufficient evidence, accepted by internationally respected scientists, that human activity is having an effect on the climate of the planet. The effects are mostly the result of greenhouse gas emissions, and are in addition to naturally occurring climate change. The impacts of climate change on water resources are displayed in every sector of water system. The temperature and precipitation are the most important factors, which affect on water resources. On the basis of meteorological data for more than 45 years from several gauging stations is made an analysis on the peculiarities of the climatic conditions in the southeastern Bulgaria. In order to trace the variability of historical precipitation and temperature series the analysis of trend and deviations from climate mean of recommended by WMO 'climate normal' period 1961-1990 was used. Precipitation over the southeastern Bulgaria has a significant variability over wide range of temporal and spatial scales. The annual precipitation data were examined for evidence of a secular trend by calculation of a linear best fit for the 1952 to 2000. The tendency of rainfall decrease was determined. The drought period in the studied region is noticeable during the summer. It should be concluded that temperature increase and precipitation decrease conduct to drought in the region and it may have more severe impacts on agriculture, water supply and society.(Author)

  19. Theoretical and numerical investigations of TAP experiments. New approaches for variable pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Senechal, U.; Breitkopf, C. [Technische Univ. Dresden (Germany). Inst. fuer Energietechnik

    2011-07-01

    Temporal analysis of products (TAP) is a valuable tool for characterization of porous catalytic structures. Established TAP-modeling requires a spatially constant diffusion coefficient and neglect convective flows, which is only valid in Knudsen diffusion regime. Therefore in experiments, the number of molecules per pulse must be chosen accordingly. New approaches for variable process conditions are highly required. Thus, a new theoretical model is developed for estimating the number of molecules per pulse to meet these requirements under any conditions and at any time. The void volume is calculated as the biggest sphere fitting between three pellets. The total number of pulsed molecules is assumed to fill the first void volume at the inlet immediately. Molecule numbers from these calculations can be understood as maximum possible molecules at any time in the reactor to be in Knudsen diffusion regime, i.e., above the Knudsen number of 2. Moreover, a new methodology for generating a full three-dimensional geometrical representation of beds is presented and used for numerical simulations to investigate spatial effects. Based on a freely available open-source game physics engine library (BULLET), beds of arbitrary-sized pellets can be generated and transformed to CFD-usable geometry. In CFD-software (ANSYS CFX registered) a transient diffusive transport equation with time-dependent inlet boundary conditions is solved. Three different pellet diameters were investigated with 1e18 molecules per pulse, which is higher than the limit from the theoretical calculation. Spatial and temporal distributions of transported species show regions inside the reactor, where non-Knudsen conditions exist. From this results, the distance from inlet can be calculated where the theoretical pressure limit (Knudsen number equals 2) is obtained, i.e., from this point to the end of the reactor Knudsen regime can be assumed. Due to linear dependency of pressure and concentration (assuming ideal

  20. Extreme conditions over Europe and North America: role of the Atlantic Multidecadal Variability

    Science.gov (United States)

    Ruprich-Robert, Yohan; Msadek, Rym; Delworth, Tom

    2016-04-01

    The Atlantic Multidecadal Variability (AMV) is the result and possibly the source of marked modulations of the climate over many areas of the globe. For instance, the relatively warm and dry climate of North America throughout the 30-yr interval of 1931-60, during which the Dust Bowl and the 1950's drought occurred, has been linked to the concomitant warm phase of the AMV. During this period relative warm and wet conditions prevailed over Europe. After 1960, the Atlantic began to cool, and for almost three decades the North American climate turned wetter and cooler whereas Europe experienced cooler and dryer conditions. However, the shortness of the historical observations compared to the AMV period suggested by longer proxy (~60-80yr) does not allow to firmly conclude on the causal effect of the AMV. We use a model approach to isolate the causal role of the AMV on the occurrence of extreme events over Europe and North America. We present experiments based on two GFDL global climate models, a low resolution version, CM2.1 and a higher resolution model for the atmospheric component, FLOR. In both model experiments sea surface temperatures in the North Atlantic sector are restored to the observed AMV pattern, while the other basins are left fully coupled. In order to explore and robustly isolate the AMV impacts on extreme events, we use large ensemble simulations (100 members for CM2.1 and 50 for FLOR) that we run for 20 years. We find that a positive phase of the AMV increases the frequency of occurrence of drought over North America and of extremely cold/warm conditions over Northern/Central Europe during winter/summer. Interestingly, we find that the AMV impacts on these extreme conditions are modulated by the Pacific response to the AMV itself. Members that develop a weak Pacific response show more extreme events over Europe whereas those that develop a strong Pacific response show more extreme events over North America.

  1. Distribution, abundance, and diversity of stream fishes under variable environmental conditions

    Science.gov (United States)

    Christopher M. Taylor; Thomas L. Holder; Richard A. Fiorillo; Lance R. Williams; R. Brent Thomas; Melvin L. Warren

    2006-01-01

    The effects of stream size and flow regime on spatial and temporal variability of stream fish distribution, abundance, and diversity patterns were investigated. Assemblage variability and species richness were each significantly associated with a complex environmental gradient contrasting smaller, hydrologically variable stream localities with larger localities...

  2. Variable structure TITO fuzzy-logic controller implementation for a solar air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Lygouras, J.N.; Pachidis, Th. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece); Kodogiannis, V.S. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London HA1 3TP (United Kingdom); Tarchanidis, K.N. [Department of Petroleum Technology, Technological Education Institute of Kavala, GR-65404, Kavala (Greece); Koukourlis, C.S. [Laboratory of Telecommunications, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece)

    2008-04-15

    The design and implementation of a Two-Input/Two-Output (TITO) variable structure fuzzy-logic controller for a solar-powered air-conditioning system is described in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. The first affects the temperature in the generator of the solar air-conditioner, while the second, the pressure in the power loop. The difficulty of Multi-Input/Multi-Output (MIMO) systems control is how to overcome the coupling effects among each degree of freedom. First, a traditional fuzzy-controller has been designed, its output being one of the components of the control signal for each DC motor driver. Secondly, according to the characteristics of the system's dynamics coupling, an appropriate coupling fuzzy-controller (CFC) is incorporated into a traditional fuzzy-controller (TFC) to compensate for the dynamic coupling among each degree of freedom. This control strategy simplifies the implementation problem of fuzzy control, but can also improve the control performance. This mixed fuzzy controller (MFC) can effectively improve the coupling effects of the systems, and this control strategy is easy to design and implement. Experimental results from the implemented system are presented. (author)

  3. Experimental study of the permeability of concrete under variable thermal and hydric conditions

    International Nuclear Information System (INIS)

    Chen, W.

    2011-01-01

    The main objective of this study is to evaluate the variable thermal and hydric effect, with fissuration effect on the hydraulic behaviour of two concretes. Many experimental tests (saturation and permeability measurements, uniaxial and triaxial compressions tests) were carried out in order to investigate the temperature and saturation influence on the behaviour hydraulic on sound and micro-cracked concrete. Moreover, an experimental device for permeability measurement on macro-cracked concrete was realized, it allows to study the behaviour of macro-cracked of concrete confined and subjected to dry gas flow or very moist air at different temperatures. Multiaxial mechanical tests are coupled to the permeability measurements of sound concrete and micro-cracked by freezing and thawing, which allow to measuring the permeability under deviatoric load-unload with the effect of pre-cracking under stress. We also effectuated a test of relative permeability of concrete as a function of water saturation, subjected to drying and re-saturation, conditioning by the different relative humidity imposed. (author)

  4. LoRa Performance under Variable Interference and Heavy-Multipath Conditions

    Directory of Open Access Journals (Sweden)

    Kamil Staniec

    2018-01-01

    Full Text Available LoRa (or LoRaWAN is by far the best known representative of narrowband communication systems designed for the Internet of Things. As a system dedicated specifically for long-range operations, it possesses a considerable processing gain for the energetic link budget improvement and a remarkable immunity to multipath and interference. The paper describes outcomes of measurement campaigns during which the LoRa performance was tested against these two factors, that is, a heavy-multipath propagation and a controlled, variable interference generated, respectively, in a reverberation chamber and an anechoic chamber. Results allow quantitative appraisal of the system behavior under these harsh conditions with respect to LoRa’s three major configurable parameters: the spreading factor, bandwidth, and code rate. They also allow dividing LoRa configurational space into three distinct sensitivity regions: in the white region it is immune to both interference and multipath propagation, in the light-grey region it is only immune to the multipath phenomenon but sensitive to interference, and in the dark grey region LoRa is vulnerable to both phenomena.

  5. Automated Bearing Fault Diagnosis Using 2D Analysis of Vibration Acceleration Signals under Variable Speed Conditions

    Directory of Open Access Journals (Sweden)

    Sheraz Ali Khan

    2016-01-01

    Full Text Available Traditional fault diagnosis methods of bearings detect characteristic defect frequencies in the envelope power spectrum of the vibration signal. These defect frequencies depend upon the inherently nonstationary shaft speed. Time-frequency and subband signal analysis of vibration signals has been used to deal with random variations in speed, whereas design variations require retraining a new instance of the classifier for each operating speed. This paper presents an automated approach for fault diagnosis in bearings based upon the 2D analysis of vibration acceleration signals under variable speed conditions. Images created from the vibration signals exhibit unique textures for each fault, which show minimal variation with shaft speed. Microtexture analysis of these images is used to generate distinctive fault signatures for each fault type, which can be used to detect those faults at different speeds. A k-nearest neighbor classifier trained using fault signatures generated for one operating speed is used to detect faults at all the other operating speeds. The proposed approach is tested on the bearing fault dataset of Case Western Reserve University, and the results are compared with those of a spectrum imaging-based approach.

  6. Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil).

    Science.gov (United States)

    Roth, F; Lessa, G C; Wild, C; Kikuchi, R K P; Naumann, M S

    2016-05-15

    Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ(13)Corg and δ(15)N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Study of dilution of effluent discharged through a sea outfall near Mangalore using radiotracer technique

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.

    1987-01-01

    The fate of effluent discharged into water bodies is a matter of concern from the point of view of environmental pollution. Radiotracer techniques have been successfully used to study the change in concentration of effluents while being mixed with large water bodies. The technique used is to add a known concentration of radioactive tracer into the effluent stream and to measure the dilutions at different locations near the effluent discharge point with radiation detectors. M/s Mangalore Chemicals and Fertilizers Ltd (MCF) at Mangalore on the west coast of India disposes off the treated and initially diluted effluent at the rate of about 360 m 3 /h into the sea near by through an outfall extending about 100 meters into the sea. The effluent mainly contains ammonia in the range of 40-50 ppm as the pollutant. It was desired to measure the extent of dilution occurring to the effluent at a few locations of known distances along the sea shore from the discharge point of the effluent. Radiotracers 82 Br as ammonium bromide solution and tritium as tritiated water were employed for the study. The concentration measurement was done at site for 82 Br and by estimation of samples in the laboratory in the case of tritium. Dilution of the order of 1000 was obtained at about 100 meters distance for a continuous injection of about 4 hours. (author). 3 tables, 3 figures

  8. Proof-of-Concept of the Phytoimmobilization Technology for TNX Outfall Delta: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.I.

    2001-06-04

    A series of proof-of-principle studies was initiated to evaluate the soil remediation technology, phytoimmobilization, for application at the TNX Outfall Delta (TNX OD) operable unit. Phytoimmobilization involves two steps. The first step is entitled phytoextraction, and it takes place mostly during the spring and summer. During this step the plants extract contaminants from the sediment into the roots and then translocate the contaminants to the aboveground plant parts. The second step is referred to as sequestration and it takes place largely during the autumn and winter when annual plants senesce or deciduous trees drop their leaves. This step involves the immobilization of the contaminant once it leaches form the fallen leaves into a ''geomat,'' a geotextile embedded with mineral sequestering agents. This final report describes the results to date, including those reported in the status report (Kaplan et al. 2000a), those completed since the report was issued, and the preliminary calculations of the phytoimmobilization effectiveness.

  9. Trace metal concentrations in mussels in the outfall zones of thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Krishna Kumar, P.T.; Sekimoto, Hiroshi

    2008-01-01

    Many trace elements (TE) like Mn, Fe, Cu, and Zn, occur naturally in marine environments and these TE accomplish decisive functions in humans to maintain good health. Living organisms like Mytilus galloprovincialis are a rich source of TE and are grown extensively near the industrial water outfalls. Some of these TE tend to be pollutants when their elevated levels produce deleterious effects on the ecological system. As chemical analysis for TE toxicity are expensive, organisms like Mytilus galloprovincialis can be used as monitors of environmental contamination. Most studies reported so far are directed towards the effect of a single environmental factor on marine bivalves. However in the areas receiving mixed effluents from various point and non-point sources, the studies on combined effect of two or more stresses would be a more practical approach. In this paper, We investigate the heavy metal concentrations of mercury, cadmium, lead, zinc, cooper, nickel, manganese, and chromium in Mytilus galloprovincialis to provide information on the pollution of water bodies by thermal and nuclear power plants for the choice of sites from where edible mussels can be harvested. We also propose a chemometric approach developed by us using information theory to mitigate trace element toxicity in the edible part of Mytilus galloprovincialis harvested in these sites. (author)

  10. A method for calorimetric analysis in variable conditions heating; Methode d'analyse calorimetrique en regime variable

    Energy Technology Data Exchange (ETDEWEB)

    Berthier, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    By the analysis of the thermal transition conditions given by the quenching of a sample in a furnace maintained at a high temperature, it is possible to study the thermal diffusivity of some materials and those of solid state structure transformation on a qualitative as well as a quantitative standpoint. For instance the transformation energy of {alpha}-quartz into {beta}-quartz and the Wigner energy stored within neutron-irradiated beryllium oxide have been measured. (author) [French] L'analyse du regime thermique transitoire, obtenu par la trempe d'un echantillon dans l'enceinte d'un four maintenu a tres haute temperature, peut permettre l'etude de la diffusivite thermique de certains materiaux et celle des transformations structurales en phase solide, tant du point de vue qualitatif que du point de vue quantitatif (mesure de l'energie de transformation du quartz {alpha} en quartz {beta} et determination de l'energie Wigner emmagasinee par l'oxyde de beryllium irradie aux neutrons). (auteur)

  11. Variability and condition of common minnow (Phoxinus phoxinus, Cyprinidae, Cypriniformes) on the Semipalatinsk range and out of its influence

    International Nuclear Information System (INIS)

    Mitrofanov, I.V.; Matmuratov, S.A.

    2003-01-01

    Populations of common minnow (Phoxinus phoxinus) from five rivers of Irtysh and Balkhash basins were investigated. Population from the Shagan river situated inside area of Semipalatinsk Range influence. This population has normal sexual structure and high growth rate. Condition factor of all fishes is high. Population from Semipalatinsk Range has increased variability of characteristics due to increasing of stochastic part of general variability. Abnormalities of external fish morphology are not observed in this area. Asymmetry of bilateral characteristics is low. (author)

  12. A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions

    Science.gov (United States)

    Thomas, Evan A.; Graf, John C.; Weislogel, Mark M.

    2010-01-01

    The invention, a static phase separator (SPS), uses airflow and capillary wetting characteristics to passively separate a two-phase (liquid and air) flow. The device accommodates highly variable liquid wetting characteristics. The resultant design allows for a range of wetting properties from about 0 to over 90 advancing contact angle, with frequent complete separation of liquid from gas observed when using appropriately scaled test conditions. Additionally, the design accommodates a range of air-to-liquid flow-rate ratios from only liquid flow to over 200:1 air-to-liquid flow rate. The SPS uses a helix input section with an ice-cream-cone-shaped constant area cross section (see figure). The wedge portion of the cross section is on the outer edge of the helix, and collects the liquid via centripetal acceleration. The helix then passes into an increasing cross-sectional area vane region. The liquid in the helix wedge is directed into the top of capillary wedges in the liquid containment section. The transition from diffuser to containment section includes a 90 change in capillary pumping direction, while maintaining inertial direction. This serves to impinge the liquid into the two off-center symmetrical vanes by the airflow. Rather than the airflow serving to shear liquid away from the capillary vanes, the design allows for further penetration of the liquid into the vanes by the air shear. This is also assisted by locating the air exit ports downstream of the liquid drain port. Additionally, any droplets not contained in the capillary vanes are re-entrained downstream by a third opposing capillary vane, which directs liquid back toward the liquid drain port. Finally, the dual air exit ports serve to slow the airflow down, and to reduce the likelihood of shear. The ports are stove-piped into the cavity to form an unfriendly capillary surface for a wetting fluid to carryover. The liquid drain port is located at the start of the containment region, allowing for

  13. Application of the Unity Rockfall Model to Variable Surface Material Conditions

    Science.gov (United States)

    Sala, Zac; Hutchinson, D. Jean; Ondercin, Matthew

    2017-04-01

    Rockfall is a geological process that poses risks to the safe operation of transportation infrastructure in mountainous environments world wide. The Unity rockfall model was created as a tool for 3D rockfall simulation as part of the Railway Ground Hazards Research Program, studying the impact of geotechnical hazards affecting Canadian railways [1]. The Unity rockfall model demonstrates the applicability of 3D video game engines for the development of realistic simulations, leveraging high-resolution site data collected using remote sensing techniques. Currently work is being done to further calibrate the model as an engineering tool for decision support. Calibration datasets include high-resolution terrestrial LiDAR and helicopter photogrammetry data collected as part of an ongoing rockfall monitoring program along the Thompson River Valley in south-central British Columbia, Canada. Change detection techniques developed as part of the program have been used to construct a database of rockfall event history and to develop magnitude-frequency relationships for rockfalls in the area [2][3]. Data collected as part of a controlled rock-rolling field program in Christchurch, New Zealand [4] is also being utilized for model calibration. Data on block dynamics for the artificially triggered rockfalls were collected through the use of embedded motion sensors and a sixteen camera setup. These experiments provide detailed information on block kinematics, and capture each impact point of the rockfall with the slope, thus offering a valuable dataset for comparison with modelling results. The research reported here explores the ability of the game engine based modelling technique to simulate rockfall under the variable slope conditions present at each of the sites where calibration data was collected. This includes steep natural rock slopes, with debris-talus cover, as well as shallower slopes with soil cover and vegetation. The varying slope conditions in each environment

  14. Remaining Sites Verification Package for the 116-F-16, PNL Outfall and the 100-F-43, PNL Outfall Spillway. Attachment to Waste Site Reclassification Form 2006-039 and 2006-046

    International Nuclear Information System (INIS)

    Dittmer, L.M.

    2006-01-01

    The 100-F-43 waste site is the portion of the former discharge spillway for the PNL Outfall formerly existing above the ordinary high water mark of the Columbia River. The spillway consisted of a concrete flume used to discharge waste effluents from the 100-F Experimental Animal Farm. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  15. Effect of weather data aggregation on regional crop simulation for different crops, production conditions, and response variables

    NARCIS (Netherlands)

    Zhao, Gang; Hoffmann, Holger; Bussel, Van L.G.J.; Enders, Andreas; Specka, Xenia; Sosa, Carmen; Yeluripati, Jagadeesh; Tao, Fulu; Constantin, Julie; Raynal, Helene; Teixeira, Edmar; Grosz, Balázs; Doro, Luca; Zhao, Zhigan; Nendel, Claas; Kiese, Ralf; Eckersten, Henrik; Haas, Edwin; Vanuytrecht, Eline; Wang, Enli; Kuhnert, Matthias; Trombi, Giacomo; Moriondo, Marco; Bindi, Marco; Lewan, Elisabet; Bach, Michaela; Kersebaum, Kurt Christian; Rötter, Reimund; Roggero, Pier Paolo; Wallach, Daniel; Cammarano, Davide; Asseng, Senthold; Krauss, Gunther; Siebert, Stefan

    2015-01-01

    We assessed the weather data aggregation effect (DAE) on the simulation of cropping systems for different crops, response variables, and production conditions. Using 13 processbased crop models and the ensemble mean, we simulated 30 yr continuous cropping systems for 2 crops (winter wheat and

  16. RESEARCH OF EXISTENCE OF RELATIONSHIP BETWEEN VARIABLES BY THE METHOD OF CONDITION-CONSEQUENCE DECOMPOSITION OF EVENTS

    Directory of Open Access Journals (Sweden)

    V. Dron'

    2014-04-01

    Full Text Available In the work an algorithm for establishing the existence of relationship between arbitrary socio-economic variables is given. The algorithm is based on the condition-consequence decomposition of events. It involves the construction of event-model and the using two classifications – types of interdependencies between events and types of relationships between their attributes.

  17. Joint variable frame rate and length analysis for speech recognition under adverse conditions

    DEFF Research Database (Denmark)

    Tan, Zheng-Hua; Kraljevski, Ivan

    2014-01-01

    This paper presents a method that combines variable frame length and rate analysis for speech recognition in noisy environments, together with an investigation of the effect of different frame lengths on speech recognition performance. The method adopts frame selection using an a posteriori signal......-to-noise (SNR) ratio weighted energy distance and increases the length of the selected frames, according to the number of non-selected preceding frames. It assigns a higher frame rate and a normal frame length to a rapidly changing and high SNR region of a speech signal, and a lower frame rate and an increased...... frame length to a steady or low SNR region. The speech recognition results show that the proposed variable frame rate and length method outperforms fixed frame rate and length analysis, as well as standalone variable frame rate analysis in terms of noise-robustness....

  18. Accommodating Binary and Count Variables in Mediation: A Case for Conditional Indirect Effects

    Science.gov (United States)

    Geldhof, G. John; Anthony, Katherine P.; Selig, James P.; Mendez-Luck, Carolyn A.

    2018-01-01

    The existence of several accessible sources has led to a proliferation of mediation models in the applied research literature. Most of these sources assume endogenous variables (e.g., M, and Y) have normally distributed residuals, precluding models of binary and/or count data. Although a growing body of literature has expanded mediation models to…

  19. Photophysiological variability of microphytobenthic diatoms after growth in different types of culture conditions

    NARCIS (Netherlands)

    Forster, R.M.; Martin-Jézéquel, V.R.

    2005-01-01

    Microphytobenthic diatoms have great ecological importance in estuarine and coastal marine ecosystenis, yet many aspects of their physiology have not been investigated under controlled conditions. This work describes patterns in growth rates and photosynthesis in different types of culture for

  20. The Kernel Mixture Network: A Nonparametric Method for Conditional Density Estimation of Continuous Random Variables

    OpenAIRE

    Ambrogioni, Luca; Güçlü, Umut; van Gerven, Marcel A. J.; Maris, Eric

    2017-01-01

    This paper introduces the kernel mixture network, a new method for nonparametric estimation of conditional probability densities using neural networks. We model arbitrarily complex conditional densities as linear combinations of a family of kernel functions centered at a subset of training points. The weights are determined by the outer layer of a deep neural network, trained by minimizing the negative log likelihood. This generalizes the popular quantized softmax approach, which can be seen ...

  1. Moving from laboratory to real life conditions: Influence on the assessment of variability and stability of gait.

    Science.gov (United States)

    Tamburini, Paola; Storm, Fabio; Buckley, Chris; Bisi, Maria Cristina; Stagni, Rita; Mazzà, Claudia

    2018-01-01

    The availability of wearable sensors allows shifting gait analysis from the traditional laboratory settings, to daily life conditions. However, limited knowledge is available about whether alterations associated to different testing environment (e.g. indoor or outdoor) and walking protocols (e.g. free or controlled), result from actual differences in the motor behaviour of the tested subjects or from the sensitivity to these changes of the indexes adopted for the assessment. In this context, it was hypothesized that testing environment and walking protocols would not modify motor control stability in the gait of young healthy adults, who have a mature and structured gait pattern, but rather the variability of their motor pattern. To test this hypothesis, data from trunk and shank inertial sensors were collected from 19 young healthy participants during four walking tasks in different environments (indoor and outdoor) and in both controlled (i.e. following a predefined straight path) and free conditions. Results confirmed what hypothesized: variability indexes (Standard deviation, Coefficient of variation and Poincaré plots) were significantly influenced by both environment and walking conditions. Stability indexes (Harmonic ratio, Short term Lyapunov exponents, Recurrence quantification analysis and Sample entropy), on the contrary, did not highlight any change in the motor control. In conclusion, this study highlighted an influence of environment and testing condition on the assessment of specific characteristics of gait (i.e. variability and stability). In particular, for young healthy adults, both environment and testing conditions affect gait variability indexes, whereas neither affect gait stability indexes. Copyright © 2017. Published by Elsevier B.V.

  2. Radiometric ratio characterization for low-to-mid CPV modules operating in variable irradiance conditions

    Science.gov (United States)

    Vorndran, Shelby; Russo, Juan; Zhang, Deming; Gordon, Michael; Kostuk, Raymond

    2012-10-01

    In this work, a concentrating photovoltaic (CPV) design methodology is proposed which aims to maximize system efficiency for a given irradiance condition. In this technique, the acceptance angle of the system is radiometrically matched to the angular spread of the site's average irradiance conditions using a simple geometric ratio. The optical efficiency of CPV systems from flat-plate to high-concentration is plotted at all irradiance conditions. Concentrator systems are measured outdoors in various irradiance conditions to test the methodology. This modeling technique is valuable at the design stage to determine the ideal level of concentration for a CPV module. It requires only two inputs: the acceptance angle profile of the system and the site's average direct and diffuse irradiance fractions. Acceptance angle can be determined by raytracing or testing a fabricated prototype in the lab with a solar simulator. The average irradiance conditions can be found in the Typical Metrological Year (TMY3) database. Additionally, the information gained from this technique can be used to determine tracking tolerance, quantify power loss during an isolated weather event, and do more sophisticated analysis such as I-V curve simulation.

  3. Independent University Study to Assess the Performance of a Humate Amendment for Copper Detoxification at the H-12 Outfall at Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Harmon, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-06

    The overarching objective of this study was to evaluate the effectiveness of the copper detoxification process that is in place at the Savannah River Site H-12 Outfall. The testing was performed in two phases; Phase 1 assessed the safety and potential for intrinsic toxicity of the humate amendment being used at the H-12 Outfall, Borregro HA-1, as well as an alternative amendment sodium humic acid. The second phase assessed the effectiveness of Borregro HA-1 in mitigating and reducing toxic effects of copper.

  4. Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls.

    Science.gov (United States)

    Staley, Zachery R; Grabuski, Josey; Sverko, Ed; Edge, Thomas A

    2016-11-01

    Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log 10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log 10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log 10 CFU/100 ml, and 7.65 log 10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can

  5. Method for signal conditioning and data acquisition system, based on variable amplification and feedback technique

    Energy Technology Data Exchange (ETDEWEB)

    Conti, Livio, E-mail: livio.conti@uninettunouniversity.net [Facoltà di Ingegneria, Università Telematica Internazionale Uninettuno, Corso Vittorio Emanuele II 39, 00186 Rome, Italy INFN Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Sgrigna, Vittorio [Dipartimento di Matematica e Fisica, Università Roma Tre, 84 Via della Vasca Navale, I-00146 Rome (Italy); Zilpimiani, David [National Institute of Geophysics, Georgian Academy of Sciences, 1 M. Alexidze St., 009 Tbilisi, Georgia (United States); Assante, Dario [Facoltà di Ingegneria, Università Telematica Internazionale Uninettuno, Corso Vittorio Emanuele II 39, 00186 Rome, Italy INFN Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2014-08-21

    An original method of signal conditioning and adaptive amplification is proposed for data acquisition systems of analog signals, conceived to obtain a high resolution spectrum of any input signal. The procedure is based on a feedback scheme of the signal amplification with aim at maximizing the dynamic range and resolution of the data acquisition system. The paper describes the signal conditioning, digitization, and data processing procedures applied to an a priori unknown signal in order to enucleate its amplitude and frequency content for applications in different environments: on the ground, in space, or in the laboratory. An electronic board of the conditioning module has also been constructed and described. In the paper are also discussed the main fields of application and advantages of the method with respect to those known today.

  6. [Corrective effect of aromatherapy on indices of heart rate variability in students under exam stress conditions].

    Science.gov (United States)

    Abrahamyan, H T; Minasyan, S M

    2016-01-01

    There were investigated changes in indices of the activity of regulatory mechanisms of heart rhythm in student under exam stress conditions and the possibility of their correction with aid of aromatherapy. The examination stress was established to be accompanied by pronounced shifts of integral and spectral indices of heart rhythm in students, indicating to the activation of the sympathetic circuit of Autonomic Nervous System in conditions of examination stress. A positive, relaxation impact of the essential oil of orange on the investigated indices was also recorded. The latter is expressed by weakly pronounced changes or lack of them in data of integral and spectral heart rate indices in students from the experimental group, that indicates to the stabilizing effect of used ethereal oil on the psycho-physiological state of students in conditions of exam stress

  7. Method for signal conditioning and data acquisition system, based on variable amplification and feedback technique

    International Nuclear Information System (INIS)

    Conti, Livio; Sgrigna, Vittorio; Zilpimiani, David; Assante, Dario

    2014-01-01

    An original method of signal conditioning and adaptive amplification is proposed for data acquisition systems of analog signals, conceived to obtain a high resolution spectrum of any input signal. The procedure is based on a feedback scheme of the signal amplification with aim at maximizing the dynamic range and resolution of the data acquisition system. The paper describes the signal conditioning, digitization, and data processing procedures applied to an a priori unknown signal in order to enucleate its amplitude and frequency content for applications in different environments: on the ground, in space, or in the laboratory. An electronic board of the conditioning module has also been constructed and described. In the paper are also discussed the main fields of application and advantages of the method with respect to those known today

  8. On the initial conditions for a universe with variable G and c

    International Nuclear Information System (INIS)

    Gomide, F.M.; Uehara, M.

    1978-01-01

    Initial conditions are discussed for a closed universe with matter injection process and with time varying G and c. It is shown that the usual interpretation for the cosmic microwave background radiation can be accepted for this model universe, provided a certain initial condition is imposed on the Pryce-Hoyle field. The time varying c is responsible for two red-shift laws one for wave-length and the other for the frequency. If radiation temperature obeys the red-shift law for frequency, the primordial Planck spectrum can be reproduced along cosmic expansion [pt

  9. Toxicities of sediments below 10 effluent outfalls to near-coastal areas of the Gulf of Mexico

    International Nuclear Information System (INIS)

    Lewis, M.; Weber, D.; Stanley, R.

    1995-01-01

    The chemical quality and toxicities of sediments collected in the receiving waters below 10 wastewater outfalls to Northwest Florida coastal areas were evaluated at multiple stations during 1994--1996. Eight types of toxicity tests using 11 test species were used to assess acute and chronic toxicity of the sediments collected below industrial, municipal, power generation and pulp mill outfalls. The primary objectives of the study were to evaluate the relative ability of different assessment procedures to detect toxicity and to provide some much-needed perspective on the impact of major point sources on sediment quality in Gulf of Mexico estuaries. The major chemical contaminants were heavy metals and PAHs. Acute and chronic toxicities were noted. Results of tests with sediment collected at the same location but several months later often differed. The most sensitive species were mysids and an estuarine amphipod. The least sensitive species were fish and macrophyte seedlings. There was poor correlation of effluent toxicity to sediment toxicity in the receiving water. Toxicity of the effluents was greater than that of the sediments. Overall, the unavailability of relevant chronic toxicity methods, uncertain criteria for choice of control stations, lack of guidance on frequency of testing and the dynamic physical and chemical characteristics of sediments are factors that need consideration if sediment monitoring is to be part of the NPDES regulatory process

  10. Spatial Variability in Condition of Southern Rock Lobsters (Jasus edwardsii) at the Start of the Tasmanian Fishing Season.

    Science.gov (United States)

    Mendo, Tania; Simon, Cedric; Green, Bridget; Gardner, Caleb

    2016-01-01

    The southern rock lobster (Jasus edwardsii) industry in Australia favours red lobsters, which are usually caught in shallow waters, over paler (brindle) lobsters. This preference is driven partly by the Chinese market, where red is associated with luck and prosperity, and additionally, by the widely held perception within the industry that brindles have greater mortality rates during out of water transport than reds. Limited scientific evidence supports these industry observations; however, these studies did not evaluate the initial condition of lobsters. This study aimed first, to determine which variables better describe condition in J. edwardsii and second, to compare condition among lobsters in several sites around Tasmania at the typical time of high transport mortality. Male lobsters were collected from the South West, South East, East and North coast of Tasmania in late November/December 2014, which correspond to the start of the Tasmanian fishing season. A comprehensive condition assessment was applied by measuring tissue proximal composition, Brix index, Total Haemocyte Count, pH, haemocyanin and another 16 haemolymph parameters of interest. A useful framework to compare condition in J. edwardsii was established by first, using Brix index as a measure of nutritional condition, second, using pH, magnesium, and bicarbonate to evaluate differences in physiological condition and finally, using THC counts as a proxy for lobster health condition. Lobsters from different sites had different nutritional, physiological and health condition, consistent with industry observations, however our results indicate that some red shallow water lobsters exhibited poorer nutritional and health condition, while some deep water brindle lobsters were in good condition. Differences in condition could not be directly associated to catch depth of lobsters and was related to other spatially discrete factors which sometimes vary over distances <3 km.

  11. Effects of sodium intake on cardiovascular variables in humans during posture changes and ambulatory conditions

    DEFF Research Database (Denmark)

    Damgaard, M.; Gabrielsenm A.; Heer, M.

    2002-01-01

    and controlled laboratory conditions at the end of two consecutive 5-day periods with sodium intakes of 70 (low) and 250 (high) mmol/24 h or vice versa, respectively. Comparing high and low sodium intake, plasma volume and plasma protein concentrations were 9 and 8% higher in the seated and the supine position...

  12. Seed mass, viability, and germination of Japanese stiltgrass (Microstegium vimineum) under variable light and moisture conditions

    Science.gov (United States)

    Cynthia D. Huebner

    2011-01-01

    The success of Japanese stiltgrass as an invader may be due to its ability to respond to stochastic events (e.g., by sexual reproduction via chasmogamous [CH] flowers) and to maintain a beneficial genetic make-up (e.g., by self-fertilizing via cleistogamous [CL] flowers) when conditions are stable. This paper evaluates the importance of Japanese stiltgrass seed type (...

  13. Assessing the Risk Relevance of Accounting Variables in Diverse Economic conditions

    NARCIS (Netherlands)

    Brimble, M.; Hodgson, A.

    2005-01-01

    This paper examines the association between accounting information and systematic (beta) risk. We extend previous research by using an updated data set, a range of risk measures that adjust for different market and time-varying conditions, and by examining whether the long-run association has

  14. Sequential Fuzzy Diagnosis Method for Motor Roller Bearing in Variable Operating Conditions Based on Vibration Analysis

    Directory of Open Access Journals (Sweden)

    Yi Cao

    2013-06-01

    Full Text Available A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD and the relative crossing information (RCI methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO clustering algorithm, the synthesizing symptom parameters (SSP for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP, and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well.

  15. Gear fault diagnosis under variable conditions with intrinsic time-scale decomposition-singular value decomposition and support vector machine

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Zhanqiang; Qu, Jianfeng; Chai, Yi; Tang, Qiu; Zhou, Yuming [Chongqing University, Chongqing (China)

    2017-02-15

    The gear vibration signal is nonlinear and non-stationary, gear fault diagnosis under variable conditions has always been unsatisfactory. To solve this problem, an intelligent fault diagnosis method based on Intrinsic time-scale decomposition (ITD)-Singular value decomposition (SVD) and Support vector machine (SVM) is proposed in this paper. The ITD method is adopted to decompose the vibration signal of gearbox into several Proper rotation components (PRCs). Subsequently, the singular value decomposition is proposed to obtain the singular value vectors of the proper rotation components and improve the robustness of feature extraction under variable conditions. Finally, the Support vector machine is applied to classify the fault type of gear. According to the experimental results, the performance of ITD-SVD exceeds those of the time-frequency analysis methods with EMD and WPT combined with SVD for feature extraction, and the classifier of SVM outperforms those for K-nearest neighbors (K-NN) and Back propagation (BP). Moreover, the proposed approach can accurately diagnose and identify different fault types of gear under variable conditions.

  16. Observations from borehole dilution logging experiments in fractured crystalline rock under variable hydraulic conditions

    Science.gov (United States)

    Harte, Philip T.; Anderson, Alton; Williams, John H.

    2014-01-01

    Identifying hydraulically active fractures in low permeability, crystalline-bedrock aquifers requires a variety of geophysical and hydrogeophysical borehole tools and approaches. One such approach is Single Borehole Dilution Tests (SBDT), which in some low flow cases have been shown to provide greater resolution of borehole flow than other logging procedures, such as vertical differential Heat Pulse Flowmeter (HPFM) logging. Because the tools used in SBDT collect continuous profiles of water quality or dye changes, they can identify horizontal flow zones and vertical flow. We used SBDT with a food grade blue dye as a tracer and dual photometer-nephelometer measurements to identify low flow zones.SBDT were conducted at seven wells with open boreholes (exceeding 300 ft). At most of the wells HPFM logs were also collected. The seven wells are set in low-permeability, fractured granite and gneiss rocks underlying a former tetrachloroeythylene (PCE) source area at the Savage Municipal Well Superfund site in Milford, NH. Time series SBDT logs were collected at each of the seven wells under three distinct hydraulic conditions: (1) ambient conditions prior to a pump test at an adjacent well, (2) mid test, after 2-3 days of the start of the pump test, and (3) at the end of the test, after 8-9 days of the pump test. None of the SBDT were conducted under pumping conditions in the logged well. For each condition, wells were initially passively spiked with blue dye once and subsequent time series measurements were made.Measurement accuracy and precision of the photometer tool is important in SBDT when attempting to detect low rates of borehole flow. Tests indicate that under ambient conditions, none of the wells had detectable flow as measured with HPFM logging. With SBDT, 4 of the 7 showed the presence of some very low flow. None of 5 (2 of the 7 wells initially logged with HPFM under ambient conditions were not re-logged) wells logged with the HPFM during the pump test had

  17. Crosswinds Effect on the Thermal Performance of Wet Cooling Towers Under Variable Operating Conditions

    Science.gov (United States)

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

    2018-01-01

    In order to quantitatively analyze the influence of the variable operating parameters on the cooling performance of natural draft wet cooling towers (NDWCTs), a hot model test system was set up with adjustable ambient temperature and humidity, circulating water flowrate and temperature. In order to apply the hot model test results to the real tower, the crosswind Froude number is defined. The results show that the crosswind has a negative effect on the thermal performance of the cooling tower, and there is a critical crosswind velocity corresponding to the lowest cooling efficiency. According to the crosswind Froude number similarity, when the ambient temperature decreases, or the circulating water flowrate and temperature increase, the cooling tower draft force will increase, and the critical crosswind velocity will increase correspondingly.

  18. Transfer of skill engendered by complex task training under conditions of variable priority.

    Science.gov (United States)

    Boot, Walter R; Basak, Chandramallika; Erickson, Kirk I; Neider, Mark; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Voss, Michelle W; Prakash, Ruchika; Lee, HyunKyu; Low, Kathy A; Kramer, Arthur F

    2010-11-01

    We explored the theoretical underpinnings of a commonly used training strategy by examining issues of training and transfer of skill in the context of a complex video game (Space Fortress, Donchin, 1989). Participants trained using one of two training regimens: Full Emphasis Training (FET) or Variable Priority Training (VPT). Transfer of training was assessed with a large battery of cognitive and psychomotor tasks ranging from basic laboratory paradigms measuring reasoning, memory, and attention to complex real-world simulations. Consistent with previous studies, VPT accelerated learning and maximized task mastery. However, the hypothesis that VPT would result in broader transfer of training received limited support. Rather, transfer was most evident in tasks that were most similar to the Space Fortress game itself. Results are discussed in terms of potential limitations of the VPT approach. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. The idiosyncrasies of streams: local variability mitigates vulnerability of trout to changing conditions

    Science.gov (United States)

    Andrea Watts; Brooke Penaluna; Jason Dunham

    2016-01-01

    Land use and climate change are two key factors with the potential to affect stream conditions and fish habitat. Since the 1950s, Washington and Oregon have required forest practices designed to mitigate the effects of timber harvest on streams and fish. Yet questions remain about the extent to which these practices are effective. Add in the effects of climate change—...

  20. On patterns of conditional independences and covariance signs among binary variables

    Czech Academy of Sciences Publication Activity Database

    Matúš, František

    Roč. 154, č. 2 ( 2018 ), s. 511-524 ISSN 0236-5294 R&D Projects: GA ČR(CZ) GA16-12010S Institutional support: RVO:67985556 Keywords : conditional independence * covariance * correlation Subject RIV: BA - General Mathematics OBOR OECD: Statistics and probability Impact factor: 0.583, year: 2016 http://library.utia.cas.cz/separaty/ 2018 /MTR/matus-0488279.pdf

  1. Robust RNA silencing-mediated resistance to Plum pox virus under variable abiotic and biotic conditions.

    Science.gov (United States)

    Di Nicola, Elisa; Tavazza, Mario; Lucioli, Alessandra; Salandri, Laura; Ilardi, Vincenza

    2014-10-01

    Some abiotic and biotic conditions are known to have a negative impact on post-transcriptional gene silencing (PTGS), thus representing a potential concern for the production of stable engineered virus resistance traits. However, depending on the strategy followed to achieve PTGS of the transgene, different responses to external conditions can be expected. In the present study, we utilized the Nicotiana benthamiana–Plum pox virus (PPV) pathosystem to evaluate in detail the stability of intron-hairpin(ihp)-mediated virus resistance under conditions known to adversely affect PTGS. The ihp plants grown at low or high temperatures were fully resistant to multiple PPV challenges, different PPV inoculum concentrations and even to a PPV isolate differing from the ihp construct by more than 28% at the nucleotide level. In addition, infections of ihp plants with viruses belonging to Cucumovirus, Potyvirus or Tombusvirus, all known to affect PTGS at different steps, were not able to defeat PPV resistance. Low temperatures did not affect the accumulation of transgenic small interfering RNAs (siRNAs), whereas a clear increase in the amount of siRNAs was observed during infections sustained by Cucumber mosaic virus and Potato virus Y. Our results show that the above stress factors do not represent an important concern for the production,through ihp-PTGS technology, of transgenic plants having robust virus resistance traits.

  2. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    Energy Technology Data Exchange (ETDEWEB)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl [Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States)

    2014-09-15

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  3. Do climate variables and human density affect Achatina fulica (Bowditch) (Gastropoda: Pulmonata) shell length, total weight and condition factor?

    Science.gov (United States)

    Albuquerque, F S; Peso-Aguiar, M C; Assunção-Albuquerque, M J T; Gálvez, L

    2009-08-01

    The length-weight relationship and condition factor have been broadly investigated in snails to obtain the index of physical condition of populations and evaluate habitat quality. Herein, our goal was to describe the best predictors that explain Achatina fulica biometrical parameters and well being in a recently introduced population. From November 2001 to November 2002, monthly snail samples were collected in Lauro de Freitas City, Bahia, Brazil. Shell length and total weight were measured in the laboratory and the potential curve and condition factor were calculated. Five environmental variables were considered: temperature range, mean temperature, humidity, precipitation and human density. Multiple regressions were used to generate models including multiple predictors, via model selection approach, and then ranked with AIC criteria. Partial regressions were used to obtain the separated coefficients of determination of climate and human density models. A total of 1.460 individuals were collected, presenting a shell length range between 4.8 to 102.5 mm (mean: 42.18 mm). The relationship between total length and total weight revealed that Achatina fulica presented a negative allometric growth. Simple regression indicated that humidity has a significant influence on A. fulica total length and weight. Temperature range was the main variable that influenced the condition factor. Multiple regressions showed that climatic and human variables explain a small proportion of the variance in shell length and total weight, but may explain up to 55.7% of the condition factor variance. Consequently, we believe that the well being and biometric parameters of A. fulica can be influenced by climatic and human density factors.

  4. Do climate variables and human density affect Achatina fulica (Bowditch (Gastropoda: Pulmonata shell length, total weight and condition factor?

    Directory of Open Access Journals (Sweden)

    FS. Albuquerque

    Full Text Available The length-weight relationship and condition factor have been broadly investigated in snails to obtain the index of physical condition of populations and evaluate habitat quality. Herein, our goal was to describe the best predictors that explain Achatina fulica biometrical parameters and well being in a recently introduced population. From November 2001 to November 2002, monthly snail samples were collected in Lauro de Freitas City, Bahia, Brazil. Shell length and total weight were measured in the laboratory and the potential curve and condition factor were calculated. Five environmental variables were considered: temperature range, mean temperature, humidity, precipitation and human density. Multiple regressions were used to generate models including multiple predictors, via model selection approach, and then ranked with AIC criteria. Partial regressions were used to obtain the separated coefficients of determination of climate and human density models. A total of 1.460 individuals were collected, presenting a shell length range between 4.8 to 102.5 mm (mean: 42.18 mm. The relationship between total length and total weight revealed that Achatina fulica presented a negative allometric growth. Simple regression indicated that humidity has a significant influence on A. fulica total length and weight. Temperature range was the main variable that influenced the condition factor. Multiple regressions showed that climatic and human variables explain a small proportion of the variance in shell length and total weight, but may explain up to 55.7% of the condition factor variance. Consequently, we believe that the well being and biometric parameters of A. fulica can be influenced by climatic and human density factors.

  5. Remaining useful life estimation in heterogeneous fleets working under variable operating conditions

    International Nuclear Information System (INIS)

    Al-Dahidi, Sameer; Di Maio, Francesco; Baraldi, Piero; Zio, Enrico

    2016-01-01

    The availability of condition monitoring data for large fleets of similar equipment motivates the development of data-driven prognostic approaches that capitalize on the information contained in such data to estimate equipment Remaining Useful Life (RUL). A main difficulty is that the fleet of equipment typically experiences different operating conditions, which influence both the condition monitoring data and the degradation processes that physically determine the RUL. We propose an approach for RUL estimation from heterogeneous fleet data based on three phases: firstly, the degradation levels (states) of an homogeneous discrete-time finite-state semi-markov model are identified by resorting to an unsupervised ensemble clustering approach. Then, the parameters of the discrete Weibull distributions describing the transitions among the states and their uncertainties are inferred by resorting to the Maximum Likelihood Estimation (MLE) method and to the Fisher Information Matrix (FIM), respectively. Finally, the inferred degradation model is used to estimate the RUL of fleet equipment by direct Monte Carlo (MC) simulation. The proposed approach is applied to two case studies regarding heterogeneous fleets of aluminium electrolytic capacitors and turbofan engines. Results show the effectiveness of the proposed approach in predicting the RUL and its superiority compared to a fuzzy similarity-based approach of literature. - Highlights: • The prediction of the remaining useful life for heterogeneous fleets is addressed. • A data-driven prognostics approach based on a Markov model is proposed. • The proposed approach is applied to two different heterogeneous fleets. • The results are compared with those obtained by a fuzzy similarity-based approach.

  6. REVEAL II: Seasonality and spatial variability of particle and visibility conditions in the Fraser Valley

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.

    2000-01-01

    This paper presents data collected during a year-long field experiment (REVEAL II) in the Fraser Valley, British Columbia. The data are used to provide information regarding ambient visibility conditions and fine particle concentrations in the valley. Although average fine mass measured during RE...... taken at a number of sites during REVEAL II are used to evaluate a simple method for obtaining (classed) quantitative estimates of visual range from this medium without requiring access to specialized instrumentation. (C) 2000 Elsevier Science B.V. All rights reserved....

  7. Flatfish recruitment response to decadal climatic variability and ocean conditions in the eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, T. K.; Hollowed, A. B.; Ingraham, W. J.; Spencer, P. D.; Conners, M. E.; Bond, N. A.; Walters, G. E.

    2002-10-01

    This paper provides a retrospective analysis of the relationship of physical oceanography and biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole ( Hippoglossoides elassodon), northern rock sole ( Lepidopsetta polyxystra), and arrowtooth flounder ( Atheresthes stomias) for the period 1978-1996. Temporal trends in flatfish production in the Eastern Bering Sea are consistent with the hypothesis that decadal scale climate variability influences marine survival during the early life history period. Density-dependence (spawning stock size) is statistically significant in a Ricker model of flatfish recruitment, which includes environmental terms. Wind-driven advection of flatfish larvae to favorable nursery grounds was also found to coincide with years of above-average recruitment through the use of an ocean surface current simulation model (OSCURS). Ocean forcing of Bristol Bay surface waters during springtime was mostly shoreward (eastward) during the 1980s and seaward (westerly) during the 1990s, corresponding with periods of good and poor recruitment. Distance from shore and water depth at the endpoint of 90-day drift periods (estimated time of settlement) were also found to correspond with flatfish productivity.

  8. Reliability and risk evaluation of a port oil pipeline transportation system in variable operation conditions

    International Nuclear Information System (INIS)

    Soszynska, Joanna

    2010-01-01

    The semi-Markov model of the system operation processes is proposed and its selected characteristics are determined. A system composed on multi-state components is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the port oil pipeline transportation system. The pipeline system is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the pipeline system operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The piping different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the pipeline lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found.

  9. Reliability and risk evaluation of a port oil pipeline transportation system in variable operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Soszynska, Joanna, E-mail: joannas@am.gdynia.p [Department of Mathematics, Gdynia Maritime University, ul. Morska 83, 81-225 Gdynia (Poland)

    2010-02-15

    The semi-Markov model of the system operation processes is proposed and its selected characteristics are determined. A system composed on multi-state components is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the port oil pipeline transportation system. The pipeline system is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the pipeline system operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The piping different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the pipeline lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found.

  10. Control-limit preventive maintenance policies for components subject to imperfect preventive maintenance and variable operational conditions

    International Nuclear Information System (INIS)

    You Mingyi; Li Hongguang; Meng Guang

    2011-01-01

    This paper develops two component-level control-limit preventive maintenance (PM) policies for systems subject to the joint effect of partial recovery PM acts (imperfect PM acts) and variable operational conditions, and investigates the properties of the proposed policies. The extended proportional hazards model (EPHM) is used to model the system failure likelihood influenced by both factors. Several numerical experiments are conducted for policy property analysis, using real lifetime and operational condition data and typical characterization of imperfect PM acts and maintenance durations. The experimental results demonstrate the necessity of considering both factors when they do exist, characterize the joint effect of the two factors on the performance of an optimized PM policy, and explore the influence of the loading sequence of time-varying operational conditions on the performance of an optimized PM policy. The proposed policies extend the applicability of PM optimization techniques.

  11. Anthropogenic modifications to drainage conditions on streamflow variability in the Wabash River basin, Indiana

    Science.gov (United States)

    Chiu, C.; Bowling, L. C.

    2011-12-01

    The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.

  12. Monsoon variability in the Himalayas under the condition of global warming

    International Nuclear Information System (INIS)

    Duan Keqin; Yao Tandong

    2003-01-01

    An ice core-drilling program was carried out at the accumulation area of Dasuopu glacier (28deg23'N, 85deg43'E, 7100 m a.s.l.) in the central Himalayas in 1997. The ice core was analyzed continuously for stable isotopes (δ 18 O), and major ions throughout the core. Cycles indicated by δ 18 O, cations were identified and counted as seasonal fluctuations as annual increment from maximum to maximum values. Reconstructed 300-year annual net accumulation (water equivalent) from the core, with a good correlation to Indian monsoon, reflects a major precipitation trend in the central Himalayas. The accumulation trend, separated from the time series, shows a strong negative correlation to Northern Hemisphere temperature. Generally, as northern hemisphere temperature increases 0.1degC, the accumulation decreases about 80 mm, reflecting monsoon rainfall in the central Himalayas has decreased over the past decades in the condition of global warming. (author)

  13. General conditions for maximal violation of non-contextuality in discrete and continuous variables

    International Nuclear Information System (INIS)

    Laversanne-Finot, A; Ketterer, A; Coudreau, T; Keller, A; Milman, P; Barros, M R; Walborn, S P

    2017-01-01

    The contextuality of quantum mechanics can be shown by the violation of inequalities based on measurements of well chosen observables. An important property of such observables is that their expectation value can be expressed in terms of probabilities for obtaining two exclusive outcomes. Examples of such inequalities have been constructed using either observables with a dichotomic spectrum or using periodic functions obtained from displacement operators in phase space. Here we identify the general conditions on the spectral decomposition of observables demonstrating state independent contextuality of quantum mechanics. Our results not only unify existing strategies for maximal violation of state independent non-contextuality inequalities but also lead to new scenarios enabling such violations. Among the consequences of our results is the impossibility of having a state independent maximal violation of non-contextuality in the Peres–Mermin scenario with discrete observables of odd dimensions. (paper)

  14. Identification of two-phase flow regimes under variable gravity conditions

    International Nuclear Information System (INIS)

    Kamiel S Gabriel; Huawei Han

    2005-01-01

    Full text of publication follows: Two-phase flow is becoming increasingly important as we move into new and more aggressive technologies in the twenty-first century. Some of its many applications include the design of efficient heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers and energy transport systems. Two-phase flow has many applications in reduced gravity environments experienced in orbiting spacecraft and earth observation satellites. Examples are heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers. A concave parallel plate capacitance sensor has been developed to measure void fraction for the purpose of objectively identifying flow regimes. The sensor has been used to collect void-fraction data at microgravity conditions aboard the NASA and ESA zero-gravity aircraft. It is shown that the flow regimes can be objectively determined from the probability density functions of the void fraction signals. It was shown that under microgravity conditions four flow regimes exist: bubbly flow, characterized by discrete gas bubbles flowing in the liquid; slug flow, consisting of Taylor bubbles separated by liquid slugs which may or may not contain several small gas bubbles; transitional flow, characterized by the liquid flowing as a film at the tube wall, and the gas phase flowing in the center with the frequent appearance of chaotic, unstable slugs; and annular flow in which the liquid flows as a film along the tube wall and the gas flows uninterrupted through the center. Since many two-phase flow models are flow regime dependent, a method that can accurately and objectively determine flow regimes is required. (authors)

  15. Identification of two-phase flow regimes under variable gravity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kamiel S Gabriel [University of Ontario Institute of Technology 2000 Simcoe Street North, Oshawa, ON L1H 7K4 (Canada); Huawei Han [Mechanical Engineering Department, University of Saskatchewan 57 Campus Dr., Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2005-07-01

    Full text of publication follows: Two-phase flow is becoming increasingly important as we move into new and more aggressive technologies in the twenty-first century. Some of its many applications include the design of efficient heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers and energy transport systems. Two-phase flow has many applications in reduced gravity environments experienced in orbiting spacecraft and earth observation satellites. Examples are heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers. A concave parallel plate capacitance sensor has been developed to measure void fraction for the purpose of objectively identifying flow regimes. The sensor has been used to collect void-fraction data at microgravity conditions aboard the NASA and ESA zero-gravity aircraft. It is shown that the flow regimes can be objectively determined from the probability density functions of the void fraction signals. It was shown that under microgravity conditions four flow regimes exist: bubbly flow, characterized by discrete gas bubbles flowing in the liquid; slug flow, consisting of Taylor bubbles separated by liquid slugs which may or may not contain several small gas bubbles; transitional flow, characterized by the liquid flowing as a film at the tube wall, and the gas phase flowing in the center with the frequent appearance of chaotic, unstable slugs; and annular flow in which the liquid flows as a film along the tube wall and the gas flows uninterrupted through the center. Since many two-phase flow models are flow regime dependent, a method that can accurately and objectively determine flow regimes is required. (authors)

  16. Characterization Activities to Determine the Extent of DNAPL in the Vadose Zone at the A-014 Outfall of A/M Area

    International Nuclear Information System (INIS)

    Jackson, D.G.

    2000-01-01

    The purpose of this investigation was to perform characterization activities necessary to confirm the presence and extent of DNAPL in the shallow vadose zone near the headwaters of the A-014 Outfall. Following the characterization, additional soil vapor extraction wells and vadose monitoring probes were installed to promote and monitor remediation activities in regions of identified DNAPL

  17. Use of energy-dispersive x-ray microanalysis as a rapid method for demarcating areas around marine outfalls that may be influenced by effluent: a case study

    CSIR Research Space (South Africa)

    Gregory, MA

    2005-01-01

    Full Text Available Surveys that monitor pollution in a marine environment often include the measurement of heavy metals and other trace elements in sediments obtained from multiple stations near marine outfalls. This study investigates the use of energy-dispersive x...

  18. Genetic Loci Governing Grain Yield and Root Development under Variable Rice Cultivation Conditions

    Directory of Open Access Journals (Sweden)

    Margaret Catolos

    2017-10-01

    Full Text Available Drought is the major abiotic stress to rice grain yield under unpredictable changing climatic scenarios. The widely grown, high yielding but drought susceptible rice varieties need to be improved by unraveling the genomic regions controlling traits enhancing drought tolerance. The present study was conducted with the aim to identify quantitative trait loci (QTLs for grain yield and root development traits under irrigated non-stress and reproductive-stage drought stress in both lowland and upland situations. A mapping population consisting of 480 lines derived from a cross between Dular (drought-tolerant and IR64-21 (drought susceptible was used. QTL analysis revealed three major consistent-effect QTLs for grain yield (qDTY1.1, qDTY1.3, and qDTY8.1 under non-stress and reproductive-stage drought stress conditions, and 2 QTLs for root traits (qRT9.1 for root-growth angle and qRT5.1 for multiple root traits, i.e., seedling-stage root length, root dry weight and crown root number. The genetic locus qDTY1.1 was identified as hotspot for grain yield and yield-related agronomic and root traits. The study identified significant positive correlations among numbers of crown roots and mesocotyl length at the seedling stage and root length and root dry weight at depth at later stages with grain yield and yield-related traits. Under reproductive stage drought stress, the grain yield advantage of the lines with QTLs ranged from 24.1 to 108.9% under upland and 3.0–22.7% under lowland conditions over the lines without QTLs. The lines with QTL combinations qDTY1.3+qDTY8.1 showed the highest mean grain yield advantage followed by lines having qDTY1.1+qDTY8.1 and qDTY1.1+qDTY8.1+qDTY1.3, across upland/lowland reproductive-stage drought stress. The identified QTLs for root traits, mesocotyl length, grain yield and yield-related traits can be immediately deployed in marker-assisted breeding to develop drought tolerant high yielding rice varieties.

  19. The Karush–Kuhn–Tucker optimality conditions in minimum weight design of elastic rotating disks with variable thickness and density

    Directory of Open Access Journals (Sweden)

    Sanaz Jafari

    2011-10-01

    Full Text Available Rotating discs work mostly at high angular velocity. High speed results in large centrifugal forces in discs and induces large stresses and deformations. Minimizing weight of such disks yields various benefits such as low dead weights and lower costs. In order to attain a certain and reliable analysis, disk with variable thickness and density is considered. Semi-analytical solutions for the elastic stress distribution in rotating annular disks with uniform and variable thicknesses and densities are obtained under plane stress assumption by authors in previous works. The optimum disk profile for minimum weight design is achieved by the Karush–Kuhn–Tucker (KKT optimality conditions. Inequality constrain equation is used in optimization to make sure that maximum von Mises stress is always less than yielding strength of the material of the disk.

  20. Influence of experimental conditions on data variability in the liver comet assay.

    Science.gov (United States)

    Guérard, M; Marchand, C; Plappert-Helbig, U

    2014-03-01

    The in vivo comet assay has increasingly been used for regulatory genotoxicity testing in recent years. While it has been demonstrated that the experimental execution of the assay, for example, electrophoresis or scoring, can have a strong impact on the results; little is known on how initial steps, that is, from tissue sampling during necropsy up to slide preparation, can influence the comet assay results. Therefore, we investigated which of the multitude of steps in processing the liver for the comet assay are most critical. All together eight parameters were assessed by using liver samples of untreated animals. In addition, two of those parameters (temperature and storage time of liver before embedding into agarose) were further investigated in animals given a single oral dose of ethyl methanesulfonate at dose levels of 50, 100, and 200 mg/kg, 3 hr prior to necropsy. The results showed that sample cooling emerged as the predominant influence factor, whereas variations in other elements of the procedure (e.g., size of the liver piece sampled, time needed to process the liver tissue post-mortem, agarose temperature, or time of lysis) seem to be of little relevance. Storing of liver samples of up to 6 hr under cooled conditions did not cause an increase in tail intensity. In contrast, storing the tissue at room temperature, resulted in a considerable time-dependent increase in comet parameters. Copyright © 2013 Wiley Periodicals, Inc.

  1. Neural dynamics of audiovisual speech integration under variable listening conditions: an individual participant analysis.

    Science.gov (United States)

    Altieri, Nicholas; Wenger, Michael J

    2013-01-01

    Speech perception engages both auditory and visual modalities. Limitations of traditional accuracy-only approaches in the investigation of audiovisual speech perception have motivated the use of new methodologies. In an audiovisual speech identification task, we utilized capacity (Townsend and Nozawa, 1995), a dynamic measure of efficiency, to quantify audiovisual integration. Capacity was used to compare RT distributions from audiovisual trials to RT distributions from auditory-only and visual-only trials across three listening conditions: clear auditory signal, S/N ratio of -12 dB, and S/N ratio of -18 dB. The purpose was to obtain EEG recordings in conjunction with capacity to investigate how a late ERP co-varies with integration efficiency. Results showed efficient audiovisual integration for low auditory S/N ratios, but inefficient audiovisual integration when the auditory signal was clear. The ERP analyses showed evidence for greater audiovisual amplitude compared to the unisensory signals for lower auditory S/N ratios (higher capacity/efficiency) compared to the high S/N ratio (low capacity/inefficient integration). The data are consistent with an interactive framework of integration, where auditory recognition is influenced by speech-reading as a function of signal clarity.

  2. Modeling Time-Dependent Behavior of Concrete Affected by Alkali Silica Reaction in Variable Environmental Conditions.

    Science.gov (United States)

    Alnaggar, Mohammed; Di Luzio, Giovanni; Cusatis, Gianluca

    2017-04-28

    Alkali Silica Reaction (ASR) is known to be a serious problem for concrete worldwide, especially in high humidity and high temperature regions. ASR is a slow process that develops over years to decades and it is influenced by changes in environmental and loading conditions of the structure. The problem becomes even more complicated if one recognizes that other phenomena like creep and shrinkage are coupled with ASR. This results in synergistic mechanisms that can not be easily understood without a comprehensive computational model. In this paper, coupling between creep, shrinkage and ASR is modeled within the Lattice Discrete Particle Model (LDPM) framework. In order to achieve this, a multi-physics formulation is used to compute the evolution of temperature, humidity, cement hydration, and ASR in both space and time, which is then used within physics-based formulations of cracking, creep and shrinkage. The overall model is calibrated and validated on the basis of experimental data available in the literature. Results show that even during free expansions (zero macroscopic stress), a significant degree of coupling exists because ASR induced expansions are relaxed by meso-scale creep driven by self-equilibriated stresses at the meso-scale. This explains and highlights the importance of considering ASR and other time dependent aging and deterioration phenomena at an appropriate length scale in coupled modeling approaches.

  3. Review of Oceanographic and Geochemical Data Collected in Massachusetts Bay during a Large Discharge of Total Suspended Solids from Boston's Sewage-Treatment System and Ocean Outfall in August 2002

    Science.gov (United States)

    Bothner, Michael H.; Butman, Bradford; Casso, Michael A.

    2010-01-01

    During the period August 14-23, 2002, the discharge of total suspended solids (TSS) from the Massachusetts Water Resources Authority sewage-treatment plant ranged from 32 to 132 milligrams per liter, causing the monthly average discharge to exceed the limit specified in the National Pollution Discharge Elimination System permit. Time-series monitoring data collected by the U.S. Geological Survey in western Massachusetts Bay were examined to evaluate changes in environmental conditions during and after this exceedance event. The rate of sediment trapping and the concentrations of near-bottom suspended sediment measured near the outfall in western Massachusetts Bay increased during this period. Because similar increases in sediment-trapping rate were observed in the summers of 2003 and 2004, however, the increase in 2002 cannot be definitively attributed to the increased TSS discharge. Concentrations of copper and silver in trapped sediment collected 10 and 20 days following the 2002 TSS event were elevated compared to those in pre-event samples. Maximum concentrations were less than 50 percent of toxicity guidelines. Photographs of surficial bottom sediments obtained before and after the TSS event do not show sediment accumulation on the sea floor. Concentrations of silver, Clostridium perfringens, and clay in surficial bottom sediments sampled 10 weeks after the discharge event at a depositional site 3 kilometers west of the outfall were unchanged from those in samples obtained before the event. Simulation of the TSS event by using a coupled hydrodynamic-wave-sediment-transport model could enhance understanding of these observations and of the effects of the exceedance on the local marine environment.

  4. Variable gene dispersal conditions and spatial deforestation patterns can interact to affect tropical tree conservation outcomes.

    Directory of Open Access Journals (Sweden)

    Yamini Kashimshetty

    Full Text Available Tropical lowland rain forest (TLRF biodiversity is under threat from anthropogenic factors including deforestation which creates forest fragments of different sizes that can further undergo various internal patterns of logging. Such interventions can modify previous equilibrium abundance and spatial distribution patterns of offspring recruitment and/or pollen dispersal. Little is known about how these aspects of deforestation and fragmentation might synergistically affect TLRF tree recovery demographics and population genetics in newly formed forest fragments. To investigate these TLRF anthropogenic disturbance processes we used the computer program NEWGARDEN (NG, which models spatially-explicit, individual-based plant populations, to simulate 10% deforestation in six different spatial logging patterns for the plant functional type of a long-lived TLRF canopy tree species. Further, each logging pattern was analyzed under nine varying patterns of offspring versus pollen dispersal distances that could have arisen post-fragmentation. Results indicated that gene dispersal condition (especially via offspring had a greater effect on population growth and genetic diversity retention (explaining 98.5% and 88.8% of the variance respectively than spatial logging pattern (0.2% and 4.7% respectively, with 'Near' distance dispersal maximizing population growth and genetic diversity relative to distant dispersal. Within logged regions of the fragment, deforestation patterns closer to fragment borders more often exhibited lower population recovery rates and founding genetic diversity retention relative to more centrally located logging. These results suggest newly isolated fragments have populations that are more sensitive to the way in which their offspring and pollen dispersers are affected than the spatial pattern in which subsequent logging occurs, and that large variation in the recovery rates of different TLRF tree species attributable to altered gene

  5. Variable gene dispersal conditions and spatial deforestation patterns can interact to affect tropical tree conservation outcomes.

    Science.gov (United States)

    Kashimshetty, Yamini; Pelikan, Stephan; Rogstad, Steven H

    2015-01-01

    Tropical lowland rain forest (TLRF) biodiversity is under threat from anthropogenic factors including deforestation which creates forest fragments of different sizes that can further undergo various internal patterns of logging. Such interventions can modify previous equilibrium abundance and spatial distribution patterns of offspring recruitment and/or pollen dispersal. Little is known about how these aspects of deforestation and fragmentation might synergistically affect TLRF tree recovery demographics and population genetics in newly formed forest fragments. To investigate these TLRF anthropogenic disturbance processes we used the computer program NEWGARDEN (NG), which models spatially-explicit, individual-based plant populations, to simulate 10% deforestation in six different spatial logging patterns for the plant functional type of a long-lived TLRF canopy tree species. Further, each logging pattern was analyzed under nine varying patterns of offspring versus pollen dispersal distances that could have arisen post-fragmentation. Results indicated that gene dispersal condition (especially via offspring) had a greater effect on population growth and genetic diversity retention (explaining 98.5% and 88.8% of the variance respectively) than spatial logging pattern (0.2% and 4.7% respectively), with 'Near' distance dispersal maximizing population growth and genetic diversity relative to distant dispersal. Within logged regions of the fragment, deforestation patterns closer to fragment borders more often exhibited lower population recovery rates and founding genetic diversity retention relative to more centrally located logging. These results suggest newly isolated fragments have populations that are more sensitive to the way in which their offspring and pollen dispersers are affected than the spatial pattern in which subsequent logging occurs, and that large variation in the recovery rates of different TLRF tree species attributable to altered gene dispersal

  6. Response time variability under slow and fast-incentive conditions in children with ASD, ADHD and ASD+ADHD.

    Science.gov (United States)

    Tye, Charlotte; Johnson, Katherine A; Kelly, Simon P; Asherson, Philip; Kuntsi, Jonna; Ashwood, Karen L; Azadi, Bahare; Bolton, Patrick; McLoughlin, Gráinne

    2016-12-01

    Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) show significant behavioural and genetic overlap. Both ADHD and ASD are characterised by poor performance on a range of cognitive tasks. In particular, increased response time variability (RTV) is a promising indicator of risk for both ADHD and ASD. However, it is not clear whether different indices of RTV and changes to RTV according to task conditions are able to discriminate between the two disorders. Children with ASD (n = 19), ADHD (n = 18), ASD + ADHD (n = 29) and typically developing controls (TDC; n = 26) performed a four-choice RT task with slow-baseline and fast-incentive conditions. Performance was characterised by mean RT (MRT), standard deviation of RT (SD-RT), coefficient of variation (CV) and ex-Gaussian distribution measures of Mu, Sigma and Tau. In the slow-baseline condition, categorical diagnoses and trait measures converged to indicate that children with ADHD-only and ASD + ADHD demonstrated increased MRT, SD-RT, CV and Tau compared to TDC and ASD-only. Importantly, greater improvement in MRT, SD-RT and Tau was demonstrated in ADHD and ASD + ADHD from slow-baseline to fast-incentive conditions compared to TDC and ASD-only. Slower and more variable RTs are markers of ADHD compared to ASD and typically developing controls during slow and less rewarding conditions. Energetic factors and rewards improve task performance to a greater extent in children with ADHD compared to children with ASD. These findings suggest that RTV can be distinguished in ASD, ADHD and ASD + ADHD based on the indices of variability used and the conditions in which they are elicited. Further work identifying neural processes underlying increased RTV is warranted, in order to elucidate disorder-specific and disorder-convergent aetiological pathways. © 2016 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for

  7. Hydraulic conditions of flood flows in a Polish Carpathian river subjected to variable human impacts

    Science.gov (United States)

    Radecki-Pawlik, Artur; Czech, Wiktoria; Wyżga, Bartłomiej; Mikuś, Paweł; Zawiejska, Joanna; Ruiz-Villanueva, Virginia

    2016-04-01

    Channel morphology of the Czarny Dunajec River, Polish Carpathians, has been considerably modified as a result of channelization and gravel-mining induced channel incision, and now it varies from a single-thread, incised or regulated channel to an unmanaged, multi-thread channel. We investigated effects of these distinct channel morphologies on the conditions for flood flows in a study of 25 cross-sections from the middle river course where the Czarny Dunajec receives no significant tributaries and flood discharges increase little in the downstream direction. Cross-sectional morphology, channel slope and roughness of particular cross-section parts were used as input data for the hydraulic modelling performed with the 1D steady-flow HEC-RAS model for discharges with recurrence interval from 1.5 to 50 years. The model for each cross-section was calibrated with the water level of a 20-year flood from May 2014, determined shortly after the flood on the basis of high-water marks. Results indicated that incised and channelized river reaches are typified by similar flow widths and cross-sectional flow areas, which are substantially smaller than those in the multi-thread reach. However, because of steeper channel slope in the incised reach than in the channelized reach, the three river reaches differ in unit stream power and bed shear stress, which attain the highest values in the incised reach, intermediate values in the channelized reach, and the lowest ones in the multi-thread reach. These patterns of flow power and hydraulic forces are reflected in significant differences in river competence between the three river reaches. Since the introduction of the channelization scheme 30 years ago, sedimentation has reduced its initial flow conveyance by more than half and elevated water stages at given flood discharges by about 0.5-0.7 m. This partly reflects a progressive growth of natural levees along artificially stabilized channel banks. By contrast, sediments of natural

  8. Single walled carbon nanotubes on MHD unsteady flow over a porous wedge with thermal radiation with variable stream conditions

    Directory of Open Access Journals (Sweden)

    R. Kandasamy

    2016-03-01

    Full Text Available The objective of the present work was to investigate theoretically the effect of single walled carbon nanotubes (SWCNTs in the presence of water and seawater with variable stream condition due to solar radiation energy. The conclusion is drawn that the flow motion and the temperature field for SWCNTs in the presence of base fluid are significantly influenced by magnetic field, convective radiation and thermal stratification. Thermal boundary layer of SWCNTs-water is compared to that of Cu-water, absorbs the incident solar radiation and transits it to the working fluid by convection.

  9. Assessment of metals bioaccumulation and bioavailability in mussels Mytilus galloprovincialis exposed to outfalls pollution in coastal areas of Casablanca.

    Science.gov (United States)

    Mejdoub, Zineb; Zaid, Younes; Hmimid, Fouzia; Kabine, Mostafa

    2018-07-01

    The present work aims to study the metallic contamination of four sampling sites located nearby major sewage outfalls of the Casablanca coast (Morocco), using indigenous mussels Mytilus galloprovincialis as bioindicators of pollution. This research offered the opportunity to study trace metals bioaccumulation mechanisms, which represent a major factor in assessment processes of the pollution effects in coastal ecosystem health. The bioavailability and the bioaccumulation of trace metals (Cu, Zn, Ni, Pb) were evaluated in order to compare the metallic contamination in mussels' tissues and find a possible correlation with physiological parameters of this filter feeding species. Our results showed a significant spatiotemporal variation of bioaccumulation, compared to control. A significant correlation coefficient between metals (Zn and Pb) bioavailability and physiological index (CI) was revealed in mussels from the most polluted location. The seasonal variation of trace metal accumulation was also raised; the highest values recorded during the dry period. Copyright © 2018 Elsevier GmbH. All rights reserved.

  10. Variable coupling between sap-flow and transpiration in pine trees under drought conditions

    Science.gov (United States)

    Preisler, Yakir; Tatarinov, Fyodor; Rohatyn, Shani; Rotenberg, Eyal; Grunzweig, Jose M.; Yakir, Dan

    2016-04-01

    Changes in diurnal patterns in water transport and physiological activities in response to changes in environmental conditions are important adjustments of trees to drought. The rate of sap flow (SF) in trees is expected to be in agreement with the rate of tree-scale transpiration (T) and provides a powerful measure of water transport in the soil-plant-atmosphere system. The aim of this five-years study was to investigate the temporal links between SF and T in Pinus halepensis exposed to extreme seasonal drought in the Yatir forest in Israel. We continuously measured SF (20 trees), the daily variations in stem diameter (ΔDBH, determined with high precision dendrometers; 8 trees), and ecosystem evapotranspiration (ET; eddy covariance), which were complemented with short-term campaigns of leaf-scale measurements of H2O and CO2 gas exchange, water potentials, and hydraulic conductivity. During the rainy season, tree SF was well synchronized with ecosystem ET, reaching maximum rates during midday in all trees. However, during the dry season, the daily SF trends greatly varied among trees, allowing a classification of trees into three classes: 1) Trees that remain with SF maximum at midday, 2) trees that advanced their SF peak to early morning, and 3) trees that delayed their SF peak to late afternoon hours. This classification remained valid for the entire study period (2010-2015), and strongly correlated with tree height and DBH, and to a lower degree with crown size and competition index. In the dry season, class 3 trees (large) tended to delay the timing of SF maximum to the afternoon, and to advance their maximum diurnal DBH to early morning, while class 2 trees (smaller) advanced their SF maximum to early morning and had maximum daily DBH during midday and afternoon. Leaf-scale transpiration (T), measurements showed a typical morning peak in all trees, irrespective of classification, and a secondary peak in the afternoon in large trees only. Water potential and

  11. Dietary fat affects heat production and other variables of equine performance, under hot and humid conditions.

    Science.gov (United States)

    Kronfeld, D S

    1996-07-01

    Does dietary fat supplementation during conditioning improve athletic performance, especially in the heat? Fat adaptation has been used to increase energy density, decrease bowel bulk and faecal output and reduce health risks associated with hydrolysable carbohydrate overload. It may also reduce spontaneous activity and reactivity (excitability), increase fatty acid oxidation, reduce CO2 production and associated acidosis, enhance metabolic regulation of glycolysis, improve both aerobic and anaerobic performance and substantially reduce heat production. A thermochemical analysis of ATP generation showed the least heat release during the direct oxidation of long chain fatty acids, which have a 3% advantage over glucose and 20 to 30% over short chain fatty acids and amino acids. Indirect oxidation via storage as triglyceride increased heat loss during ATP generation by 3% for stearic acid, 65% for glucose and 174% for acetic acid. Meal feeding and nutrient storage, therefore, accentuates the advantage of dietary fat. A calorimetric model was based on initial estimates of net energy for competitive work (10.76 MJ for the Endurance Test of an Olympic level 3-day-event), other work (14.4 MJ/day) and maintenance (36 MJ), then applied estimates of efficiencies to derive associated heat productions for the utilisation of 3 diets, Diet A: hay (100), Diet B: hay and oats (50:50) and Diet C: hay, oats and vegetable oil (45:45:10), the difference between the last 2 diets representing fat adaptation. During a 90.5 min speed and stamina test, heat production was estimated as 37, 35.4 and 34.6 MJ for the 3 diets, respectively, an advantage 0.8 MJ less heat load for the fat adapted horse, which would reduce water needed for evaporation by 0.33 kg and reduce body temperature increase by about 0.07 degree C. Total estimated daily heat production was 105, 93 and 88 MJ for the 3 diets, respectively, suggesting a 5 MJ advantage for the fat adapted horse (Diet C vs. Diet B). Estimated

  12. Increasing Juniperus virginiana L. pollen in the Tulsa atmosphere: long-term trends, variability, and influence of meteorological conditions

    Science.gov (United States)

    Flonard, Michaela; Lo, Esther; Levetin, Estelle

    2018-02-01

    In the Tulsa area, the Cupressaceae is largely represented by eastern red cedar ( Juniperus virginiana L.). The encroachment of this species into the grasslands of Oklahoma has been well documented, and it is believed this trend will continue. The pollen is known to be allergenic and is a major component of the Tulsa atmosphere in February and March. This study examined airborne Cupressaceae pollen data from 1987 to 2016 to determine long-term trends, pollen seasonal variability, and influence of meteorological variables on airborne pollen concentrations. Pollen was collected through means of a Burkard sampler and analyzed with microscopy. Daily pollen concentrations and yearly pollen metrics showed a high degree of variability. In addition, there were significant increases over time in the seasonal pollen index and in peak concentrations. These increases parallel the increasing population of J. virginiana in the region. Pollen data were split into pre- and post-peak categories for statistical analyses, which revealed significant differences in correlations of the two datasets when analyzed with meteorological conditions. While temperature and dew point, among others were significant in both datasets, other factors, like relative humidity, were significant only in one dataset. Analyses using wind direction showed that southerly and southwestern winds contributed to increased pollen concentrations. This study confirms that J. virginiana pollen has become an increasing risk for individuals sensitive to this pollen and emphasizes the need for long-term aerobiological monitoring in other areas.

  13. Effects from influent boundary conditions on tracer migration and spatial variability features in intermediate-scale experiments

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Springer, E.P.

    1987-04-01

    In previous unsaturated transport studies at Los Alamos dispersion coefficients were estimated to be higher close to the tracer source than at greater distances from the source. Injection of tracers through discrete influent outlets could have accounted for those higher dispersions. Also, a lack of conservation of mass of the tracers was observed and suspected to be due to spatial variability in transport. In the present study experiments were performed under uniform influent (ponded) conditions in which breakthrough of tracers was monitored at four locations at each of four depths. All other conditions were similar to those of the unsaturated transport experiments. A comparison of results from these two sets of experiments indicates differences in the parameter estimates. Estimates were made for the dispersion coefficient and the retardation factor by the one-dimensional steady flow computer code, CFITIM. Estimates were also made for mass and for velocity and the dispersion coefficient by the method of moments. The dispersion coefficient decreased with depth under discrete influent application and increased with depth under ponded influent application. Retardation was predicted better under the discrete influent application than under ponded influent application. Differences in breakthroughs and in estimated parameters among locations at the same depth were observed under ponded influent application. Those differences indicate that there is a lack of conservation of mass as well as significant spatial variability across the experimental domain. 14 refs., 9 figs., 8 tabs

  14. Analysis of wall-embedded Langmuir probe signals in different conditions on the Tokamak à Configuration Variable

    Science.gov (United States)

    Février, O.; Theiler, C.; De Oliveira, H.; Labit, B.; Fedorczak, N.; Baillod, A.

    2018-05-01

    This paper presents the current wall-embedded Langmuir probe system installed on the Tokamak à Configuration Variable (TCV), as well as the analysis tool chain used to interpret the current-voltage characteristic obtained when the probes are operated in swept-bias conditions. The analysis is based on a four-parameter fit combined with a minimum temperature approach. In order to reduce the effect of plasma fluctuations and measurement noise, several current-voltage characteristics are usually averaged before proceeding to the fitting. The impact of this procedure on the results is investigated, as well as the possible role of finite resistances in the circuitry, which could lead to an overestimation of the temperature. We study the application of the procedure in a specific regime, the plasma detachment, where results from other diagnostics indicate that the electron temperature derived from the Langmuir probes might be overestimated. To address this issue, we explore other fitting models and, in particular, an extension of the asymmetric double probe fit, which features effects of sheath expansion. We show that these models yield lower temperatures (up to approximately 60%) than the standard analysis in detached conditions, particularly for a temperature peak observed near the plasma strike point, but a discrepancy with other measurements remains. We explore a possible explanation for this observation, the presence of a fast electron population, and assess how robust the different methods are in such conditions.

  15. Microcontroller Based Proportional Derivative Plus Conditional Integral Controller for Electro-Mechanical Dual Acting Pulley Continuously Variable Transmission Ratio Control

    International Nuclear Information System (INIS)

    Budianto, A; Tawi, K B; Hussein, M; Supriyo, B; Kob, M S Che; Zulkifli, Mohd Ezlamy; Khairuldean A K; Daraoh, Aishah; Ariyono, S

    2012-01-01

    Electro-Mechanical Dual Acting Pulley (EMDAP) Continuously Variable Transmission (CVT) is a transmission utilized by electro-mechanical actuated system. It has a potential to reduce energy consumption because it only needs power during changing CVT ratio and no power is needed to maintain CVT ratio due to self lock mechanism design. This paper proposed simple proportional derivative plus conditional integral (PDCI) controller to control EMDAP CVT ratio which can be simply implemented on a microcontroller. This proposed controller used Astrom-Hagglund method and Ziegler-Nichols formula to tune PDCI gain. The Proportional Derivative controller is directly activated from the start but Integral controller is only activated when the error value reaches error value setting point. Simulation using Matlab/Simulink software was conducted to evaluate PDCI system performance. The simulation results showed PDCI controller has ability to perform maximum overshoot 0.1%, 0.001 steady state error and 0.5s settling time. For clamping condition, settling time is about 11.46s during changing ratio from 2.0 to 0.7, while for release condition, settling time is about 8.33s during changing ratio from 0.7 to 2.0.

  16. ANALYSES OF GENETIC VARIABILITY IN LENTINULA EDODES THROUGH MYCELIA RESPONSES TO DIFFERENT ABIOTIC CONDITIONS AND RAPD MOLECULAR MARKERS

    Directory of Open Access Journals (Sweden)

    Maki Cristina Sayuri

    2001-01-01

    Full Text Available The growth of thirty-four Lentinula edodes strains submitted to different mycelial cultivation conditions (pH and temperature was evaluated and strain variability was assessed by RAPD molecular markers. The growth at three pH values (5, 6 and 7 and four different temperatures (16, 25, 28 and 37ºC was measured using the in vitro mycelial development rate and water retention as parameters. Mycelial cultivation was successful at all pH tested, while the ideal temperature for mycelial cultivation ranged between 25 and 28ºC. The water content was lower in strains grown at 37ºC. Among 20 OPA primers (Operon Technologies, Inc. used for the RAPD analyses, seventeen presented good polymorphism (OPA01 to OPA05, OPA07 to OPA14, OPA17 to OPA20. The clustering based on similarity coefficients allowed the separation of strain in two groups with different geographic origins.

  17. Variability of morphological conditions of the Vistula river channel in the section Czerwińsk-Kępa Polska

    Directory of Open Access Journals (Sweden)

    Popek Zbigniew

    2015-03-01

    Full Text Available Variability of morphological conditions of the Vistula river channel in the section Czerwińsk-Kępa Polska. The paper presents an assessment of morphological changes that occurred in the Vistula river channel in selected section of about 33 km long, located in the middle of the Vistula river course between Czerwińsk and Kępa Polska (km 576–609. Based on the analysis of archival material from 1972–2009, a characteristics of river channel changes, taking primarily into account the horizontal layout (shape in the plan, was obtained. An attempt was made to estimate the trends and rate of transformation of the following parameters in the river channel: width, length, and position of the riverbanks, abundance and size of islands and fluvial deposits, as well as their percentage in the total area of the main river channel and the floodplain area between levees.

  18. Variability of contrail formation conditions and the implications for policies to reduce the climate impacts of aviation

    International Nuclear Information System (INIS)

    Williams, Victoria; Noland, Robert B.

    2005-01-01

    This paper describes an approach to balance the climate benefits of contrail reduction against the penalties incurred when cruise altitudes are restricted. Altitude restrictions are targeted by selecting, for each 6-h period, the altitude that provides the greatest reduction in contrail for the lowest increase in carbon dioxide emission. Calculations are for western Europe. This paper discusses the variability in contrail formation conditions in the region and presents contrail reductions and carbon dioxide emission increases obtained with this optimised approach, which compare favourably with fixed altitude restrictions. A new method is also developed to estimate contrail fractions within three-dimensional grids. Conclusions discuss potential operational issues associated with a varying altitude restriction policy. (Author)

  19. Smearing model and restoration of star image under conditions of variable angular velocity and long exposure time.

    Science.gov (United States)

    Sun, Ting; Xing, Fei; You, Zheng; Wang, Xiaochu; Li, Bin

    2014-03-10

    The star tracker is one of the most promising attitude measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.

  20. Regression-based season-ahead drought prediction for southern Peru conditioned on large-scale climate variables

    Science.gov (United States)

    Mortensen, Eric; Wu, Shu; Notaro, Michael; Vavrus, Stephen; Montgomery, Rob; De Piérola, José; Sánchez, Carlos; Block, Paul

    2018-01-01

    Located at a complex topographic, climatic, and hydrologic crossroads, southern Peru is a semiarid region that exhibits high spatiotemporal variability in precipitation. The economic viability of the region hinges on this water, yet southern Peru is prone to water scarcity caused by seasonal meteorological drought. Meteorological droughts in this region are often triggered during El Niño episodes; however, other large-scale climate mechanisms also play a noteworthy role in controlling the region's hydrologic cycle. An extensive season-ahead precipitation prediction model is developed to help bolster the existing capacity of stakeholders to plan for and mitigate deleterious impacts of drought. In addition to existing climate indices, large-scale climatic variables, such as sea surface temperature, are investigated to identify potential drought predictors. A principal component regression framework is applied to 11 potential predictors to produce an ensemble forecast of regional January-March precipitation totals. Model hindcasts of 51 years, compared to climatology and another model conditioned solely on an El Niño-Southern Oscillation index, achieve notable skill and perform better for several metrics, including ranked probability skill score and a hit-miss statistic. The information provided by the developed model and ancillary modeling efforts, such as extending the lead time of and spatially disaggregating precipitation predictions to the local level as well as forecasting the number of wet-dry days per rainy season, may further assist regional stakeholders and policymakers in preparing for drought.

  1. Permafrost hydrology in changing climatic conditions: seasonal variability of stable isotope composition in rivers in discontinuous permafrost

    International Nuclear Information System (INIS)

    Streletskiy, Dmitry A; Shiklomanov, Nikolay I; Nyland, Kelsey E; Tananaev, Nikita I; Opel, Thomas; Streletskaya, Irina D; Tokarev, Igor’; Shiklomanov, Alexandr I

    2015-01-01

    Role of changing climatic conditions on permafrost degradation and hydrology was investigated in the transition zone between the tundra and forest ecotones at the boundary of continuous and discontinuous permafrost of the lower Yenisei River. Three watersheds of various sizes were chosen to represent the characteristics of the regional landscape conditions. Samples of river flow, precipitation, snow cover, and permafrost ground ice were collected over the watersheds to determine isotopic composition of potential sources of water in a river flow over a two year period. Increases in air temperature over the last forty years have resulted in permafrost degradation and a decrease in the seasonal frost which is evident from soil temperature measurements, permafrost and active-layer monitoring, and analysis of satellite imagery. The lowering of the permafrost table has led to an increased storage capacity of permafrost affected soils and a higher contribution of ground water to river discharge during winter months. A progressive decrease in the thickness of the layer of seasonal freezing allows more water storage and pathways for water during the winter low period making winter discharge dependent on the timing and amount of late summer precipitation. There is a substantial seasonal variability of stable isotopic composition of river flow. Spring flooding corresponds to the isotopic composition of snow cover prior to the snowmelt. Isotopic composition of river flow during the summer period follows the variability of precipitation in smaller creeks, while the water flow of larger watersheds is influenced by the secondary evaporation of water temporarily stored in thermokarst lakes and bogs. Late summer precipitation determines the isotopic composition of texture ice within the active layer in tundra landscapes and the seasonal freezing layer in forested landscapes as well as the composition of the water flow during winter months. (letter)

  2. Determining the Variability of Lesion Size Measurements from CT Patient Data Sets Acquired under “No Change” Conditions

    Directory of Open Access Journals (Sweden)

    Michael F. McNitt-Gray

    2015-02-01

    Full Text Available PURPOSE: To determine the variability of lesion size measurements in computed tomography data sets of patients imaged under a “no change” (“coffee break” condition and to determine the impact of two reading paradigms on measurement variability. METHOD AND MATERIALS: Using data sets from 32 non-small cell lung cancer patients scanned twice within 15 minutes (“no change”, measurements were performed by five radiologists in two phases: (1 independent reading of each computed tomography dataset (timepoint: (2 a locked, sequential reading of datasets. Readers performed measurements using several sizing methods, including one-dimensional (1D longest in-slice dimension and 3D semi-automated segmented volume. Change in size was estimated by comparing measurements performed on both timepoints for the same lesion, for each reader and each measurement method. For each reading paradigm, results were pooled across lesions, across readers, and across both readers and lesions, for each measurement method. RESULTS: The mean percent difference (±SD when pooled across both readers and lesions for 1D and 3D measurements extracted from contours was 2.8 ± 22.2% and 23.4 ± 105.0%, respectively, for the independent reads. For the locked, sequential reads, the mean percent differences (±SD reduced to 2.52 ± 14.2% and 7.4 ± 44.2% for the 1D and 3D measurements, respectively. CONCLUSION: Even under a “no change” condition between scans, there is variation in lesion size measurements due to repeat scans and variations in reader, lesion, and measurement method. This variation is reduced when using a locked, sequential reading paradigm compared to an independent reading paradigm.

  3. Community structure of fish and macrobenthos at selected sites fronting Sand Island, Oahu, Hawaii in relation to the Sand Island Deep Ocean Sewage Outfall, 1990 - 1998 (NODC Accession 0000177)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report provides the results of nine years of an annual quantitative monitoring of shallow marine communities inshore of the Sand Island Ocean Outfall, Oahu,...

  4. Interrater and intrarater agreements of magnetic resonance imaging findings in the lumbar spine: significant variability across degenerative conditions.

    Science.gov (United States)

    Fu, Michael C; Buerba, Rafael A; Long, William D; Blizzard, Daniel J; Lischuk, Andrew W; Haims, Andrew H; Grauer, Jonathan N

    2014-10-01

    agreement. However, when stratified by condition, absolute interrater agreement ranged from 65.1% to 92.0%. Disc hydration, disc space height, and bone marrow changes exhibited the lowest absolute interrater agreements. The absolute intrarater agreement had a narrower range, from 74.5% to 91.5%. Fleiss kappa coefficients ranged from fair-to-substantial agreement (0.282-0.618). Even in a study using standardized evaluation criteria, there was significant variability in the interrater and intrarater agreements of MRI in assessing different degenerative conditions of the lumbar spine. Clinicians should be aware of the condition-specific diagnostic limitations of MRI interpretation. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Environmental monitoring near the Macaulay Point and Clover Point marine sewage outfalls at Victoria, British Columbia in 1989 and 1990. Regional data report No. DR 92-14

    Energy Technology Data Exchange (ETDEWEB)

    Colodey, A G; Salmon, R A; Lim, P G

    1992-01-01

    The marine environment surrounding the Capital Region district (CRD) of British Columbia that includes the City of Victoria has been monitored by municipal, provincial, and federal authorities over the past 20 years to determine the impact of wastewater discharges. This report presents data from limited sampling conducted near the main CRD deep-water outfalls at Clover and Macaulay Points, the Canadian Department of National Defence septic tank outfall off Belmont and Esquimault Lagoon, and reference locations on Constance Bank and Discovery Island. Samples for this study were collected in April and October 1989, and April 1990. Parameters investigated were sediment and biota trace metals, sediment particle size, sediment volatile residues, visual descriptions of sediment, bacterial counts, water conductivity, temperature, salinity, and dissolved oxygen.

  6. Effects of formulation variables on viability of L. casei loaded in whey protein-Ca alginate microparticles in simulated in vivo conditions

    OpenAIRE

    Smilkov, Katarina; Petrusevska Tozi, Lidija; Petreska Ivanovska, Tanja; Geskovski, Nikola; Petkovska, Rumenka; Glavas Dodov, Marija; Baceva, Katerina; Dimitrovski, Dejan; Mladenovska, Kristina

    2011-01-01

    The objective of this work was to assess the influence of formulation variables of L. casei loaded whey protein-Ca-alginate microparticles on probiotic survival under different conditions, representing simulated in vivo environment.

  7. Short and long term variability of the interrupter technique under field and standardised conditions in 3-6 year old children

    NARCIS (Netherlands)

    Beelen, RMJ; Smit, HA; van Strien, RT; Koopman, LP; Brussee, JE; Brunekreef, B; Gerritsen, J; Merkus, PJFM

    2003-01-01

    Background: The short and long term variability of the interrupter technique was assessed to determine whether interrupter resistance is a stable individual characteristic over time. The effect of field and standardised measurement conditions on the within-subject variability of the interrupter

  8. Short-term heart rate variability in asthmatic obese children: effect of exhaustive exercise and different humidity conditions.

    Science.gov (United States)

    Rezvan, K; Dabidi Roshan, V; Mahmudi, S A

    2015-11-01

    Asthmatic obese children experience changes in functional capacity and autonomic control. Previous heart rate variability (HRV) studies were based on 24-hour recordings, little research has been conducted on the short-term HRV in asthmatic obese children, primarily during physical effort indifferent environmental humidity conditions. The aim of this study was to evaluate the effect of aerobic activity on short-term HRV in asthmatic obese children under two different environmental humidity conditions. Ten obese boys with mild asthma as experimental group and 15 obese healthy boys with the same conditions were involved as a control group. Protocol included progressive and exhaustive aerobic activities on a calibrated ergometer pedal bicycle in two various environmental humidity 35±5% and 65±5%. HRV was measured by PADSY MEDSET Holter monitoring device during three phases; pre-test, mid-test and post-test. Then, short-term HRV was assessed from calculation of the mean R-R interval measured on HRV at each phases. HRV significantly decreased at mid-test and post-test among asthmatic and health children. However, the aforesaid changes were significantly higher in the asthmatic than health children following. Moreover, decrease of short-term HRV was significantly greater in the 35±5% than 65±5% environmental humidity. Our findings suggest from the autonomic standpoint, asthmatic and non-asthmatic children respond differently to exhaustive exercise induced stress. Aerobic exercise at an environment with high humidity compared with the low humidity appears to have additional benefits on short-term HRV in that it enhances the parasympathetic and autonomic modulation of the heart in asthmatic obese children.

  9. MODEL-ASSISTED ESTIMATION OF THE GENETIC VARIABILITY IN PHYSIOLOGICAL PARAMETERS RELATED TO TOMATO FRUIT GROWTH UNDER CONTRASTED WATER CONDITIONS

    Directory of Open Access Journals (Sweden)

    Dario Constantinescu

    2016-12-01

    Full Text Available Drought stress is a major abiotic stres threatening plant and crop productivity. In case of fleshy fruits, understanding Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fleshy fruits, understanding mechanisms governing water and carbon accumulations and identifying genes, QTLs and phenotypes, that will enable trade-offs between fruit growth and quality under Water Deficit (WD condition is a crucial challenge for breeders and growers. In the present work, 117 recombinant inbred lines of a population of Solanum lycopersicum were phenotyped under control and WD conditions. Plant water status, fruit growth and composition were measured and data were used to calibrate a process-based model describing water and carbon fluxes in a growing fruit as a function of plant and environment. Eight genotype-dependent model parameters were estimated using a multiobjective evolutionary algorithm in order to minimize the prediction errors of fruit dry and fresh mass throughout fruit development. WD increased the fruit dry matter content (up to 85 % and decreased its fresh weight (up to 60 %, big fruit size genotypes being the most sensitive. The mean normalized root mean squared errors of the predictions ranged between 16-18 % in the population. Variability in model genotypic parameters allowed us to explore diverse genetic strategies in response to WD. An interesting group of genotypes could be discriminated in which i the low loss of fresh mass under WD was associated with high active uptake of sugars and low value of the maximum cell wall extensibility, and ii the high dry matter content in control treatment (C was associated with a slow decrease of mass flow. Using 501 SNP markers genotyped across the genome, a QTL analysis of model parameters allowed to detect three main QTLs related to xylem and phloem conductivities, on chromosomes 2, 4 and 8. The model was then applied to design ideotypes with high dry matter

  10. Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

    International Nuclear Information System (INIS)

    Murphy, J.M.; Mason, C.F.V.; Boak, J.M.; Longmire, P.A.

    1996-01-01

    Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site

  11. Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.M.; Mason, C.F.V.; Boak, J.M.; Longmire, P.A.

    1996-04-01

    Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site.

  12. Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

    Science.gov (United States)

    Li, Yongkang; Yang, Yang; He, Changyan

    2018-06-01

    Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

  13. Decadal variability of drought conditions over the southern part of Europe based on Principal Oscillation Pattern Analysis

    Science.gov (United States)

    Ionita-Scholz, Monica; Tallaksen, Lena M.; Scholz, Patrick

    2017-04-01

    This study introduces a novel method of estimating the decay time, mean period and forcing statistics of drought conditions over large spatial domains, demonstrated here for southern part of Europe (10°E - 40°E, 35°N - 50°N). It uses a two-dimensional stochastically forced damped linear oscillator model with the model parameters estimated from a Principal Oscillation Pattern (POP) analysis and associated observed power spectra. POP is a diagnostic technique that aims to derive the space-time characteristics of a data set objectively. This analysis is performed on an extended observational time series of 114 years (1902 - 2015) of the Standardized Precipitation Evapotranspiration Index for an accumulation period of 12 months (SPEI12), based on the Climate Research Unit (CRU TS v. 3.24) data set. The POP analysis reveals four exceptionally stable modes of variability, which together explain more than 62% of the total explained variance. The most stable POP mode, which explains 16.3% of the total explained variance, is characterized by a period of oscillation of 14 years and a decay time of 31 years. The real part of POP1 is characterized by a monopole-like structure with the highest loadings over Portugal, western part of Spain and Turkey. The second stable mode, which explains 15.9% of the total explained variance, is characterized by a period of oscillation of 20 years and a decay time of 26.4 years. The spatial structure of the real part of POP2 has a dipole-like structure with the highest positive loadings over France, southern Germany and Romania and negative loadings over southern part of Spain. The third POP mode, in terms of stability, explains 14.0% of the total variance and is characterized by a period of oscillation of 33 years and a decay time of 43.5 years. The real part of POP3 is characterized by negative loadings over the eastern part of Europe and positive loadings over Turkey. The fourth stable POP mode, explaining 15.5% of the total variance

  14. Short seed longevity, variable germination conditions, and infrequent establishment events provide a narrow window for Yucca brevifolia (Agavaceae) recruitment

    Science.gov (United States)

    Bryant, M.; Reynolds, J.; DeFalco, Lesley A.; Esque, Todd C.

    2012-01-01

    PREMISE OF THE STUDY: The future of long-lived stand-forming desert plants such as Yucca brevifolia (Joshua tree) has come into question in light of climate variation and landscape-scale disturbances such as wildfire. Understanding plant establishment dynamics is important for mitigating the impacts of disturbances and promoting revegetation. • METHODS: We placed Y. brevifolia seeds in shallow caches and manipulated granivore access, nurse shrub effects, and the season of cache placement to determine conditions for seed germination and seedling establishment. • KEY RESULTS: Greatest seedling emergence occurred during spring and summer, when increased soil moisture was accompanied by warm soil temperatures. Late winter-spring emergence for cached seeds was enhanced beneath shrub canopies, but seedling survival declined beneath shrubs as temperatures increased in spring. Germinability of seed remaining in the soil was reduced from 50-68% after 12 mo residence time in soil and declined to germinability, imposing substantial losses of potential germinants. • CONCLUSIONS: Specific germination and establishment requirements impose stringent limits on recruitment rates for Y. brevifolia. Coupled with infrequent seed availability, the return rates to prefire densities and demographic structure may require decades to centuries, especially in light of potential changes to regional desert climate in combination with the potential for fire recurrence. Demographic patterns are predicted to vary spatially in response to environmental variability that limits recruitment and may already be apparent among extant populations.

  15. Analysis of vegetation condition and its relationship with meteorological variables in the Yarlung Zangbo River Basin of China

    Directory of Open Access Journals (Sweden)

    X. Han

    2018-06-01

    Full Text Available The Yarlung Zangbo River Basin is located in the southwest border of China, which is of great significance to the socioeconomic development and ecological environment of Southwest China. Normalized Difference Vegetation Index (NDVI is an important index for investigating the change of vegetation cover, which is widely used as the representation value of vegetation cover. In this study, the NDVI is adopted to explore the vegetation condition in the Yarlung Zangbo River Basin during the recent 17 years, and the relationship between NDVI and meteorological variables has also been discussed. The results show that the annual maximum value of NDVI usually appears from July to September, in which August occupies a large proportion. The minimum value of NDVI appears from January to March, in which February takes up most of the percentage. The higher values of NDVI are generally located in the lower elevation area. When the altitude is higher than 3250 m, NDVI began to decline gradually, and the NDVI became gradual stabilization as the elevation is up to 6000 m. The correlation coefficient between NDVI and precipitation in the Yarlung Zangbo River Basin is greater than that with temperature. The Hurst index of the whole basin is 0.51, indicating that the NDVI of the Yarlung Zangbo River Basin shows a weak sustainability.

  16. Comparative study of the reliability of MPPT algorithms for the crystalline silicon photovoltaic modules in variable weather conditions

    Directory of Open Access Journals (Sweden)

    Abraham Dandoussou

    2017-05-01

    Full Text Available The crystalline silicon photovoltaic modules are widely used as power supply sources in the tropical areas where the weather conditions change abruptly. Fortunately, many MPPT algorithms are implemented to improve their performance. In the other hand, it is well known that these power supply sources are nonlinear dipoles and so, their intrinsic parameters may vary with the irradiance and the temperature. In this paper, the MPPT algorithms widely used, i.e. Perturb and Observe (P&O, Incremental Conductance (INC, Hill-Climbing (HC, are implemented using Matlab®/Simulink® model of a crystalline silicon photovoltaic module whose intrinsic parameters were extracted by fitting the I(V characteristic to experimental points. Comparing the simulation results, it is obvious that the variable step size INC algorithm has the best reliability than both HC and P&O algorithms for the near to real Simulink® model of photovoltaic modules. With a 60 Wp photovoltaic module, the daily maximum power reaches 50.76 W against 34.40 W when the photovoltaic parameters are fixed. Meanwhile, the daily average energy is 263 Wh/day against 195 Wh/day.

  17. Investigation on output capacity control strategy of variable refrigerant flow air conditioning system with multi-compressor

    International Nuclear Information System (INIS)

    Tu, Qiu; Zou, Deqiu; Deng, Chenmian; Zhang, Jie; Hou, Lifeng; Yang, Min; Nong, Guicai; Feng, Yuhai

    2016-01-01

    Highlights: • The control model of compressor output capacity has been built. • The control strategy of compressor switching has been presented. • The switching process of standard compressor has been described. • The characteristics of EER and noise have been presented. • The control strategy and model have been proved by experiments. - Abstract: A set of 14 HP variable refrigerant flow air conditioning system (VRF AC) with multi-compressor has been designed, and the output capacity control strategy of compressor(s) including the switching control model of standard compressor has been built. In the output capacity control model, a certain suction pressure is used as the pressure control target to adjust the output capacity of compressors, and a little pressure fluctuation is taken into account to amend the target pressure. Furthermore, in the compressor switching control model, the most favorable operation frequency region is determined on base of the energy efficiency characteristic and noise characteristic of the compressor. And, in order to solve the large fluctuation problem of the system running and frequent ON-OFF action of the standard compressor, the equal output capacity switching principle can be used to determine the thermo-on and thermo-off switched frequency points, and control the switching process of the compressor. Experiments demonstrate the feasibility of this control strategy to ensure the stability and reliability, improve the energy efficiency and reduce the compressor noise.

  18. Short seed longevity, variable germination conditions, and infrequent establishment events provide a narrow window for Yucca brevifolia (Agavaceae) recruitment

    Science.gov (United States)

    Bryant, M.; Reynolds, J.; DeFalco, Lesley A.; Esque, Todd C.

    2012-01-01

    PREMISE OF THE STUDY: The future of long-lived stand-forming desert plants such as Yucca brevifolia (Joshua tree) has come into question in light of climate variation and landscape-scale disturbances such as wildfire. Understanding plant establishment dynamics is important for mitigating the impacts of disturbances and promoting revegetation. • METHODS: We placed Y. brevifolia seeds in shallow caches and manipulated granivore access, nurse shrub effects, and the season of cache placement to determine conditions for seed germination and seedling establishment. • KEY RESULTS: Greatest seedling emergence occurred during spring and summer, when increased soil moisture was accompanied by warm soil temperatures. Late winter-spring emergence for cached seeds was enhanced beneath shrub canopies, but seedling survival declined beneath shrubs as temperatures increased in spring. Germinability of seed remaining in the soil was reduced from 50-68% after 12 mo residence time in soil and declined to parent plants, seeds are either removed by granivores or lose germinability, imposing substantial losses of potential germinants. • CONCLUSIONS: Specific germination and establishment requirements impose stringent limits on recruitment rates for Y. brevifolia. Coupled with infrequent seed availability, the return rates to prefire densities and demographic structure may require decades to centuries, especially in light of potential changes to regional desert climate in combination with the potential for fire recurrence. Demographic patterns are predicted to vary spatially in response to environmental variability that limits recruitment and may already be apparent among extant populations.

  19. Inter-Labeler and Intra-Labeler Variability of Condition Severity Classification Models Using Active and Passive Learning Methods

    Science.gov (United States)

    Nissim, Nir; Shahar, Yuval; Boland, Mary Regina; Tatonetti, Nicholas P; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

    2018-01-01

    Background and Objectives Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers’ learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. Methods We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by

  20. Inter-labeler and intra-labeler variability of condition severity classification models using active and passive learning methods.

    Science.gov (United States)

    Nissim, Nir; Shahar, Yuval; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

    2017-09-01

    Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers' learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by using the labels provided by seven

  1. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Directory of Open Access Journals (Sweden)

    Asif Mahmood

    Full Text Available Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2-water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary. Keywords: Solar energy, Thermal collectors, Maxwell-nanofluid, Thermal radiation, Partial slip, Variable thermal conductivity

  2. Numerical simulation of water flow and Nitrate transport through variably saturated porous media in laboratory condition using HYDRUS 2D

    Science.gov (United States)

    Jahangeer, F.; Gupta, P. K.; Yadav, B. K.

    2017-12-01

    Due to the reducing availability of water resources and the growing competition for water between residential, industrial, and agricultural users, increasing irrigation efficiency, by several methods like drip irrigation, is a demanding concern for agricultural experts. The understanding of the water and contaminants flow through the subsurface is needed for the sustainable irrigation water management, pollution assessment, polluted site remediation and groundwater recharge. In this study, the Windows-based computer software package HYDRUS-2D, which numerically simulates water and solute movement in two-dimensional, variably-saturated porous media, was used to evaluate the distribution of water and Nitrate in the sand tank. The laboratory and simulation experiments were conducted to evaluate the role of drainage, recharge flux, and infiltration on subsurface flow condition and subsequently, on nitrate movement in the subsurface. The water flow in the unsaturated zone model by Richards' equation, which was highly nonlinear and its parameters were largely dependent on the moisture content and pressure head of the partially saturated zone. Following different cases to be considered to evaluate- a) applying drainage and recharge flux to study domains, b) transient infiltration in a vertical soil column and c) subsequently, nitrate transport in 2D sand tank setup. A single porosity model was used for the simulation of water and nitrate flow in the study domain. The results indicate the transient water table position decreases as the time increase significantly by applying drainage flux at the bottom. Similarly, the water table positions in study domains increasing in the domain by applying recharge flux. Likewise, the water flow profile shows the decreasing water table elevation with increasing water content in the vertical domain. Moreover, the nitrate movement was dominated by advective flux and highly affected by the recharge flux in the vertical direction. The

  3. Radioisotope studies on the paradox in dispersion and agglomeration of sewage greases discharged from ocean outfalls

    International Nuclear Information System (INIS)

    Davison, A.; Easy, J.F.; Seatonberry, B.W.

    1981-04-01

    Experiments have been undertaken in the ocean off Sydney, Australia to monitor the movement and the dispersion of sewage solids. These solids were labelled with a radioisotope, gold-198 prior to ocean discharge. The labelled material was followed at sea using submersible scintillation detectors. Lateral and vertical dispersion coefficients were determined. The experiments showed that under some conditions the labelled sewage grease dispersed and under others the grease agglomerated. This variation is explained in terms of non-conservative processes

  4. Water quality monitoring of river Ravi from Mehmood buti bund road to downstream Sanda main outfall, Lahore

    International Nuclear Information System (INIS)

    Tahir, S.; Ayub, M.; Tabinda, A.B.

    2005-01-01

    Water quality of River Ravi was monitored at six different sites on a stretch from Mehmood Buti Bund Road to Sanda Main Outfall Lahore for different physico-chemical parameters and heavy metals. Different water quality parameters at different sites ranged as under. Temperature ranged between 19.5 to 22.3 deg. C. pH was between 7.8 to 8.1, and maximum at Mehmood Buti Bund. Dissolved oxygen ranged between 1.71 and 9.52 mg/L, minimum at main out fall and total dissolved solids were between 40 and 213 mg/L, conductivity was between 298 to 1146 Mmhos/Cm, total alkalinity was between 111 and 463 mg/L, minimum at Mehmood Buti Bund and maximum at main out fall, total hardness was between 116 and 287 mg/L minimum at Mehmood Buti Bund and maximum at old bridge, chloride values were between 51.5 to 174 mg/L minimum near Baradari and maximum at Mehmood Buti Bund. Concentrations of Chromium, Cadmium, Nickel and Zinc ranged between 0.01 and 2.78 mg/L, 0.4 and 1.72 mg/L, 0.97 and 1.38 mg/L, 0.09 and 2.89 mg/L respectively. Minimum metal concentrations were at Mehmood Buti Bund while maximum values were at down stream of main out fall indicating more deterioration of water quality of River Ravi down streams main out fall by addition of different types of untreated industrial effluents and domestic wastewater from different operations by inhabitants of Lahore City. (author)

  5. Hydraulic considerations in deigning an oil spill control system for stormwater outfall

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.; Chui, J. [Ryerson University, Dept. of Civil Engineering, Toronto, ON (Canada)

    2004-09-01

    An oil spill control system, consisting of an on-line triangular lateral diversion channel and an off-line tilted-plate oil-water separator, installed in the Humber Creek sub-watershed in Toronto, Ontario, is described. The area, which rims the shore of Lake Ontario from the Niagara Peninsula to Oshawa, is heavily industrialized, and is home to some 5.6 million people. During the 1990s an estimated average of 1050 litre/day of petroleum products have escaped into the environment; soil contamination occurred in 55 per cent of the cases, and water-course pollution in 31 per cent. A physical model study was conducted at the National Water Research Institute's Hydraulic Laboratory in Burlington, Ontario, to investigate the hydraulic behaviour of the spill control system under different flow conditions. Results of the investigation confirmed the design conveyance capacity of the lateral diversion channel; it also confirmed that floating objects and settleable solids could be trapped inside the oil-water separator under various flow conditions. Because the angled diversion channel was observed to cause a vortex action inside the first and second chambers of the separator and increase the potential for trapped oil to be flushed out, it is recommended that the final design of the spill control system pay special attention to the vortex problem. One potential solution for this problem may be the installation of baffles at the second chamber of the oil-water separator. It was further recommended that the design should also address the flushing of trapped oil during wet weather conditions. 23 refs., 2 tabs., 10 figs.

  6. Reconstructing paleoceanographic conditions in the westernmost Mediterranean during the last 4.000 yr: tracking rapid climate variability

    Science.gov (United States)

    Nieto-Moreno, V.; Martínez-Ruiz, F.; Jiménez-Espejo, F. J.; Gallego-Torres, D.; Rodrigo-Gámiz, M.; Sakamoto, T.; Böttcher, M.; García-Orellana, J.; Ortega-Huertas, M.

    2009-04-01

    The westernmost Mediterranean (Alboran Sea basin) is a key location for paleoceanographic and paleoclimatic reconstructions since high sedimentation rates provide ultra high-resolution records at centennial and millennial scales. Here, we present a paleoenvironmental reconstruction for the last 4000 yr, which is based on a multi-proxy approach that includes major and trace element-content fluctuations and mineral composition of marine sediments. The investigated materials correspond to several gravity and box cores recovered in the Alboran Sea basin during different oceanographic cruises (TTR-14 and TTR-17), which have been sampled at very high resolution. Comparative analysis of these cores allows establishing climate oscillations at centennial to millennial scales. Although relatively more attention have been devoted to major climate changes during the last glacial cycle, such as the Last Glacial Maximun, deglaciation and abrupt cooling events (Heinrich and Younger Dryas), the late Holocene has also been punctuated by significant rapid climate variability including polar cooling, aridity and changes in the intensity of the atmospheric circulation. These climate oscillations coincide with significant fluctuations in chemical and mineral composition of marine sediments. Thus, bulk and clay mineralogy, REE composition and Rb/Al, Zr/Al, La/Lu ratios provide information on the sedimentary regime (eolian-fluvial input and source areas), Ba-based proxies on fluctuations in marine productivity and redox sensitive elements on oxygen conditions at time of deposition. A decrease in fluvial-derived elements/minerals (e.g., Rb, detrital mica) takes places during the so-called Late Bronze Age-Iron Age, Dark Age, and Little Ice Age Period. Meanwhile an increase is evidenced during the Medieval Warm Period and the Roman Humid Period. This last trend runs parallel to a decline of element/minerals of typical eolian source (Zr, kaolinite) with the exception of the Roman Humid

  7. Developmental Exposure to Mild Variable Stress: Adult Offspring Performance in Trace Fear Conditioning after Prenatal and Postnatal Stress

    Science.gov (United States)

    In utero exposure to mild variable stress has been reported to influence learning and memory formation in offspring. Our research aims to examine whether nonchemical environmental stressors will exacerbate effects to chemical exposure. This study utilized a varying stress parad...

  8. Tidal Flushing Characteristics of Municipal and Industrial Waste in the Karachi Coastal Waters and Simulation of Waste Field Dilution at Sewage Outfall

    International Nuclear Information System (INIS)

    Khan, T. M. A.; Abid, K.; Jaffery, S.; Ali, I.; Zakai, H. M. A.

    2015-01-01

    The deterioration of Karachi coast and the marine environment near to it cannot be ignored. Effluents from industries and untreated sewage discharge into the coastal waters through Malir and Lyari Rivers and this ultimately have a negative impact on marine life and also to human health. The toxicants present in the industrial wastewater play a vital role in declining the marine population and also cause contamination. The knowledge of flushing and residence times of estuaries and creeks is very important. However, the estimated flushing time by using the freshwater fraction method ranges 15-20 days at both sites. The freshwater fraction method is considered to be a reasonable estimation method as in this method salinity variation in the estuary and open sea are also incorporated in the calculation. Discharging the effluents in the estuary results the destruction of the ecosystem of the area. Thus the discharge of polluted water directly in the deep offshore water certainly improves the quality of life in the coastal areas. Therefore, submarine outfall construction is an effective way to discharge the sewage far away from the coast where diffusion, dispersion and dilution are enhanced. This paper deals with the estimation of flushing time scales and marine environmental parameters in the offshore waters of HawkesBay and Gizri creek/DHA coastlines. The outfall model, DESCAR, is used to determine the spreading and dilution of pollutants under different oceanographic and meteorological forcing. The other outfall parameters such as Initial dilution and Froude numbers and return back travel time are also estimated by using USEPA spread sheet and the ocean-atmosphere archived data. (author)

  9. Results of Toxicity Identification Evaluations (TIE'S) conducted on the A-01 outfall and its contributory waste streams, July 1996 - February 1997

    International Nuclear Information System (INIS)

    Specht, W.L.

    1997-03-01

    Toxicity tests were conducted at nine locations during the summer of 1996. The results indicated that A-01B, A-01C, A-03, A-04, A-05 and A-01 were toxic to the test species, Ceriodaphnia dubia, while A-01A, A-06, and WE-01 were not toxic. Beginning in August 1996, Toxicity Identification Evaluations (TIE's) were initiated on all toxic outfalls in order to identify the toxicants responsible for the observed toxicity. A complete TIE was performed on A-01 because it is the regulatory compliance point for all of the combined waste streams that were tested. Only the portions of a TIE that are related to metal and chlorine toxicity were performed on the remaining locations because existing data indicated that metals and chlorine were present in potentially toxic quantities at these locations, and there was no evidence that other toxicants would be expected to be present in toxic amounts. The results of the TIE's indicate that metals are responsible for most of the toxicity at all of the outfalls that were toxic and that chlorine contributed to the toxicity at two of the outfalls. Specifically, the toxicity at A-01B, A-01C, and A-01 was due to copper; the toxicity at A-03 was due to primarily to copper, although zinc also contributed to the toxicity; the toxicity at A-04 was due primarily to copper, with residual chlorine and zinc contributing to the toxicity; and the toxicity at A-05 was due primarily to copper, with residual chlorine contributing to the toxicity. A-03 was the most toxic outfall, with 100% mortality occurring at concentrations as low as 12.5% effluent. A-03 was found to have concentrations of copper, lead, and zinc that exceeded EPA water quality criteria by approximately two orders of magnitude. The metal concentrations at A-01 and WE-01, which is located approximately 0.5 miles downstream from A-01 were similar. However, A-01 was toxic, while WE-01 was not

  10. College education and wages in the UK : Estimating conditional average structural functions in nonadditive models with binary endogenous variables

    NARCIS (Netherlands)

    Klein, T.J.

    2013-01-01

    Recent studies debate how the unobserved dependence between the monetary return to college education and selection into college can be characterised. This paper examines this question using British data. We develop a semiparametric local instrumental variables estimator for identified features of a

  11. Comparison of two systems for long-term heart rate variability monitoring in free-living conditions - a pilot study

    DEFF Research Database (Denmark)

    Kristiansen, Jesper; Korshoj, Mette; Skotte, Jorgen H

    2011-01-01

    Actiheart and Holter recorders, and signals were processed to RR-interval time series. Segments of 5-minute duration were sampled every 30 minutes, and spectral components of the heart rate variability were calculated. Actiheart and Holter values were compared using Deming regression analysis and Bland...

  12. Hospitalizations for ambulatory care sensitive conditions and quality of primary care: their relation with socioeconomic and health care variables in the Madrid regional health service (Spain).

    Science.gov (United States)

    Magán, Purificación; Alberquilla, Angel; Otero, Angel; Ribera, José Manuel

    2011-01-01

    Hospitalizations for ambulatory care sensitive conditions (ACSH) have been proposed as an indirect indicator of the effectiveness and quality of care provided by primary health care. To investigate the association of ACSH rates with population socioeconomic factors and with characteristics of primary health care. Cross-sectional, ecologic study. Using hospital discharge data, ACSH were selected from the list of conditions validated for Spain. All 34 health districts in the Region of Madrid, Spain. Individuals aged 65 years or older residing in the region of Madrid between 2001 and 2003, inclusive. Age- and gender-adjusted ACSH rates in each health district. The adjusted ACSH rate per 1000 population was 35.37 in men and 20.45 in women. In the Poisson regression analysis, an inverse relation was seen between ACSH rates and the socioeconomic variables. Physician workload was the only health care variable with a statistically significant relation (rate ratio of 1.066 [95% CI; 1.041-1.091]). These results were similar in the analyses disaggregated by gender. In the multivariate analyses that included health care variables, none of the health care variables were statistically significant. ACSH may be more closely related with socioeconomic variables than with characteristics of primary care activity. Therefore, other factors outside the health system must be considered to improve health outcomes in the population.

  13. Remaining Sites Verification Package for the 116-F-8, 1904-F Outfall Structure and the 100-F-42, 1904-F Spillway. Attachment to Waste Site Reclassification Form 2006-038 and 2006-045

    International Nuclear Information System (INIS)

    Dittmer, L.M.

    2006-01-01

    The 100-F-42 waste site is the portion of the former emergency overflow spillway for the 1904-F Outfall Structure formerly existing above the ordinary high water mark of the Columbia River. The spillway consisted of a concrete flume designed to discharge effluent from the 107-F Retention Basin in the event that flows could not be completely discharged via the river outfall pipelines. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  14. Experimental Determination of Effect of Variable Resistance on Lead ZirconateTitanate (PZT-5A4Eunder various Thermal and Frequency Conditions

    Directory of Open Access Journals (Sweden)

    Hassan Elahi

    2014-12-01

    Full Text Available A specially designed apparatus and circuit working on the principle of inverse piezoelectricity due to the effect of polarization was used to find the relationship between resistance and peak to peak voltage of Lead Zirconate Titanate (PZT-5A4E by shocking it at variable frequencies and at variable resistances under various thermal conditions within Curie temperature limit using equivalent circuit method. It was found that by increasing temperature, peak to peak voltage increases and similarly by increasing frequency, peak to peak voltage decreases and with the increase in resistance peak to peak voltage decreases.

  15. Variability of thermal and precipitation conditions in the growing season in Poland in the years 1966-2015

    Science.gov (United States)

    Tomczyk, Arkadiusz M.; Szyga-Pluta, Katarzyna

    2018-03-01

    The aim of the study was to identify the thermal and precipitation conditions and their changes in the growing season in Poland in the years 1966-2015. Data on average daily air temperature and daily precipitation totals for 30 stations from the period of 1966-2015 were used. The data were obtained from the collections of the Institute of Meteorology and Water Management—National Research Institute. The growing season was defined as the period of average daily air temperature ≥ 5 °C. The mathematical formulas proposed by Gumiński (1948) were used to determine its start and end dates. In the growing season in Poland in the years 1966-2015, there were more significant changes in the thermal conditions than there were in the precipitation conditions. In terms of long-term trends over the study period, thermal conditions during the growing season are characterised by an increase in mean air temperature, an increase in the sum of air temperatures and an increasing occurrence of seasons classified as above-normal seasons. Precipitation conditions of the growing season show large temporal and spatial variations in precipitation and a predominance of normal conditions. The changes in precipitation were not statistically significant, except for Świnoujście.

  16. High Variability in Cellular Stoichiometry of Carbon, Nitrogen, and Phosphorus Within Classes of Marine Eukaryotic Phytoplankton Under Sufficient Nutrient Conditions.

    Science.gov (United States)

    Garcia, Nathan S; Sexton, Julie; Riggins, Tracey; Brown, Jeff; Lomas, Michael W; Martiny, Adam C

    2018-01-01

    Current hypotheses suggest that cellular elemental stoichiometry of marine eukaryotic phytoplankton such as the ratios of cellular carbon:nitrogen:phosphorus (C:N:P) vary between phylogenetic groups. To investigate how phylogenetic structure, cell volume, growth rate, and temperature interact to affect the cellular elemental stoichiometry of marine eukaryotic phytoplankton, we examined the C:N:P composition in 30 isolates across 7 classes of marine phytoplankton that were grown with a sufficient supply of nutrients and nitrate as the nitrogen source. The isolates covered a wide range in cell volume (5 orders of magnitude), growth rate (temperature (2-24°C). Our analysis indicates that C:N:P is highly variable, with statistical model residuals accounting for over half of the total variance and no relationship between phylogeny and elemental stoichiometry. Furthermore, our data indicated that variability in C:P, N:P, and C:N within Bacillariophyceae (diatoms) was as high as that among all of the isolates that we examined. In addition, a linear statistical model identified a positive relationship between diatom cell volume and C:P and N:P. Among all of the isolates that we examined, the statistical model identified temperature as a significant factor, consistent with the temperature-dependent translation efficiency model, but temperature only explained 5% of the total statistical model variance. While some of our results support data from previous field studies, the high variability of elemental ratios within Bacillariophyceae contradicts previous work that suggests that this cosmopolitan group of microalgae has consistently low C:P and N:P ratios in comparison with other groups.

  17. 2D simulation and performance evaluation of bifacial rear local contact c-Si solar cells under variable illumination conditions

    KAUST Repository

    Katsaounis, Theodoros

    2017-09-18

    A customized 2D computational tool has been developed to simulate bifacial rear local contact PERC type PV structures based on the numerical solution of the transport equations through the finite element method. Simulations were performed under various device material parameters and back contact geometry configurations in order to optimize bifacial solar cell performance under different simulated illumination conditions. Bifacial device maximum power output was also compared with the monofacial equivalent one and the industrial standard Al-BSF structure. The performance of the bifacial structure during highly diffused irradiance conditions commonly observed in the Middle East region due to high concentrations of airborne dust particles was also investigated. Simulation results demonstrated that such conditions are highly favorable for the bifacial device because of the significantly increased diffuse component of the solar radiation which enters the back cell surface.

  18. 2D simulation and performance evaluation of bifacial rear local contact c-Si solar cells under variable illumination conditions

    KAUST Repository

    Katsaounis, Theodoros; Kotsovos, Konstantinos; Gereige, Issam; Al-Saggaf, Ahmed; Tzavaras, Athanasios

    2017-01-01

    A customized 2D computational tool has been developed to simulate bifacial rear local contact PERC type PV structures based on the numerical solution of the transport equations through the finite element method. Simulations were performed under various device material parameters and back contact geometry configurations in order to optimize bifacial solar cell performance under different simulated illumination conditions. Bifacial device maximum power output was also compared with the monofacial equivalent one and the industrial standard Al-BSF structure. The performance of the bifacial structure during highly diffused irradiance conditions commonly observed in the Middle East region due to high concentrations of airborne dust particles was also investigated. Simulation results demonstrated that such conditions are highly favorable for the bifacial device because of the significantly increased diffuse component of the solar radiation which enters the back cell surface.

  19. The Theory of Thermodynamic Systems with Internal Variables of State: Necessary and Sufficient Conditions for Compliance with the Second Law of Thermodynamics

    Science.gov (United States)

    Shnip, A. I.

    2018-01-01

    Based on the entropy-free thermodynamic approach, a generalized theory of thermodynamic systems with internal variables of state is being developed. For the case of nonlinear thermodynamic systems with internal variables of state and linear relaxation, the necessary and sufficient conditions have been proved for fulfillment of the second law of thermodynamics in entropy-free formulation which, according to the basic theorem of the theory, are also necessary and sufficient for the existence of a thermodynamic potential. Moreover, relations of correspondence between thermodynamic systems with memory and systems with internal variables of state have been established, as well as some useful relations in the spaces of states of both types of systems.

  20. Stability of Marangoni Convection in a Fluid Layer with Variable Viscosity and deformable Free Surface under Free-Slip condition

    Directory of Open Access Journals (Sweden)

    Nurul Hafizah Zainal Abidin

    2009-01-01

    Full Text Available The steady marangoni convection is investigated in ahorizontal layer of fluid with a free-slip bottom heated frombelow and cooled from above. Since the viscosity is temperaturedependentthe consequences of relaxing oberbeck-boussinesqapproximation and free surface deformability are theoreticallyexamined by means of small disturbance analysis. Prediction forthe onset of convection are obtained from the analysis bynumerical technique. The effect of variable viscosity and surfacedeformation on the onset of fluid motion is investigated in detail.It is shown that the critical values of marangoni and wavenumber depend strongly on the viscosity variation and surfacedeformation.

  1. Genetic variability in uptake of nitrogen at various growth stages of barley and wheat under dryland conditions

    International Nuclear Information System (INIS)

    Della, A.; Hadjichristodoulou, A.

    1976-01-01

    Protein and dry matter in a number of high protein and commercial varieties of barley and wheat were tested at various growth stages and at two locations. Large genetic variability was found in uptake of nitrogen, which was taken up generally before heading. High protein yields were not associated with high protein content but with higher dry matter yields. Nitrogen fertilization increased protein content and protein yield at a low protein location only. It was concluded that it is possible to breed for both high grain and high straw protein varieties. (author)

  2. Automatization of the measurement to the environmental gamma dose rate and of meteorological variables that condition it

    International Nuclear Information System (INIS)

    Dominguez, O.; Alonso, D.; Capote, E.; Ramos, E.O.; Carrazana, J. A.; Prendes, M.; Manzano, J. F.; Tomas, J.; Kalbert, O.; Ledo, L.M.; Guibert, R.; Leyva, J.C.; Montalvan, A.; Fabelo, O.; Cartas, H.

    2004-01-01

    The National Network of Environmental Radiological Surveillance of the Republic of Cuba has strengthened its detection and answer capacity regarding its constant monitoring of the National atmospheric means. 4 type A posts of that network measure the gamma dose rate and the data are being received in real time. The CPHR as head Center receives the information of the remaining posts at a relatively short time, for a series of computer tools, has been developed for that purpose. On the other hand, in the radiological post of our center the wind speed and its direction monitoring have been automated, the information on these meteorological variables is collected in real time

  3. Gastric adenocarcinoma in common variable immunodeficiency: features of cancer and associated gastritis may be characteristic of the condition.

    Science.gov (United States)

    De Petris, Giovanni; Dhungel, Bal M; Chen, Longwen; Chang, Yu-Hui H

    2014-10-01

    Common variable immunodeficiency (CVID) is associated with an increased risk of gastric cancer. The aim of the study was to determine the morphological features of CVID-associated gastric adenocarcinoma (CAGA) and of the background gastritis. The population of gastric cancer patients with CVID of Mayo Clinic in the period 2000-2010 was studied; 6 cases of CVID (2 males, 4 females, average age 47 years, age range 26-71 years) were found in 5793 patients with gastric cancer in the study period. Each patient underwent gastric resection for which histology slides were reviewed. Chronic gastritis variables, CVID-related findings, and features of the adenocarcinoma were recorded. CAGA was of intestinal type, with high number of intratumoral lymphocytes (ITLs). Cancer was diagnosed in younger patients than in the overall population of gastric cancer. Severe atrophic metaplastic pangastritis with extensive dysplasia was present in the background in 4 cases, with features of lymphocytic gastritis in 2 cases. Features of CVID (plasma cells paucity in 4 of 6 cases, lymphoid nodules prominent in four cases) could be detected. In summary, gastric adenocarcinoma at young age with ITLs, accompanied by atrophic metaplastic pangastritis, should alert the pathologist of the possibility of CAGA. It follows that, in presence of those characteristics, the search of CVID-associated abnormalities should be undertaken in the nonneoplastic tissues. © The Author(s) 2014.

  4. Physiological age at harvest regulates the variability in postharvest ripening, sensory and nutritional characteristics of mango (Mangifera indica L.) cv. Coghshall due to growing conditions.

    Science.gov (United States)

    Joas, Jacques; Vulcain, Emmanuelle; Desvignes, Claire; Morales, Emeline; Léchaudel, Mathieu

    2012-04-01

    Climacteric fruits are harvested at the green-mature stage and ripen during their marketing cycle. However, growing conditions induce variability into the maturity stage of mangoes at harvest, with an impact on their final quality. Assuming that the physiological age can be correctly evaluated by a criterion based on the variable chlorophyll fluorescence of the skin (F(v)) and that differences in physiological age depend on growing conditions, controlled stress experiments were carried out on mango fruit by manipulating either the leaf/fruit ratio or the light environment. Delays from 9 to 30 days were observed, depending on stress level and harvest stage, to obtain the same F(v) value. For moderate stress, fruit composition after ripening was partially compensated for, with little or no difference in sugar, dry matter, carotenoid and aroma contents. For more pronounced stress, the major metabolites were not particularly affected, but the synthesis capacity of carotenoids and aromas was lower after maturity. The ripening ability of a fruit is acquired on the tree and defines its postharvest changes. Control of the physiological age at harvest can minimise the variability observed under natural conditions and guarantee fruit batches whose postharvest changes will be relatively homogeneous. Copyright © 2011 Society of Chemical Industry.

  5. Dental, periodontal and salivary conditions in diabetic children associated with metabolic control variables and nutritional plan adherence.

    Science.gov (United States)

    Díaz Rosas, C Y; Cárdenas Vargas, E; Castañeda-Delgado, J E; Aguilera-Galaviz, L A; Aceves Medina, M C

    2018-06-01

    Diabetes mellitus is a chronic disease that has manifestations other than alterations in endocrine regulation or in metabolic pathways. Several diseases of the oral cavity have been associated with diabetes mellitus type 1 and 2 in young people according to their evolution. Scarce information exists regarding the role of diabetes and its association with the oral health status in paediatric diabetic patients. The aims of the study were to assess the quality of saliva, saliva acidogenicity, dental caries experience, fluorosis and periodontal status in diabetic patients and to evaluate their relationship with metabolic control variables and nutritional plan adherence. The study population consisted of 60 paediatric patients with both types of diabetes mellitus. Saliva testing included stimulated flow, pH (using pH indicator strips), buffer capacity and Snyder's Test. DMFT/dmft and dental caries experience were determined on the basis of ICDAS II codes. The periodontal status was assessed by PI and GI and fluorosis by FI. Nutritional plan adherence was established from the subscale "Dietary Control" of the Diabetes Self-Management Profile questionnaire. Medical Data was retrieved from the clinical registers in the Diabetic Clinic. We describe the main characteristics of the oral cavity related variables of our population that might guide the clinical practice in similar settings; we found a dmft/DMFT of 1.71 ± 1.74 and 0.64 ± 1.03, PI of 1.91 ± 0.75, GI of 0.50 ± 0.56 and a fluorosis prevalence of 61%. We identified several correlated variables, which indicate strong associations between the nutritional habits of the patients and co-occurrence of oral cavity physiopathological alterations. Several correlations were found between acidogenic activity of the saliva (Snyder Test) and the percentage of adherence to the nutritional plan and to the dmft index. Furthermore, a significant correlation between the buffering capacity of the saliva and the glycemic control of

  6. Punctuated Holocene climate of Vestfirðir, Iceland, linked to internal/external variables and oceanographic conditions

    Science.gov (United States)

    Harning, David J.; Geirsdóttir, Áslaug; Miller, Gifford H.

    2018-06-01

    Emerging Holocene paleoclimate datasets point to a non-linear response of Icelandic climate against a background of steady orbital cooling. The Vestfirðir peninsula (NW Iceland) is an ideal target for continued climate reconstructions due to the presence of a small ice cap (Drangajökull) and numerous lakes, which provide two independent means to evaluate existing Icelandic climate records and to constrain the forcing mechanisms behind centennial-scale cold anomalies. Here, we present new evidence for Holocene expansions of Drangajökull based on 14C dates from entombed dead vegetation as well as two continuous Holocene lake sediment records. Lake sediments were analyzed for both bulk physical (MS) and biological (%TOC, δ13C, C/N, and BSi) parameters. Composite BSi and C/N records from the two lakes yield a sub-centennial qualitative perspective on algal (diatom) productivity and terrestrial landscape stability, respectively. The Vestfirðir lake proxies suggest initiation of the Holocene Thermal Maximum by ∼8.8 ka with subsequent and pronounced cooling not apparent until ∼3 ka. Synchronous periods of reduced algal productivity and accelerated landscape instability point to cold anomalies centered at ∼8.2, 6.6, 4.2, 3.3, 2.3, 1.8, 1, and 0.25 ka. Triggers for cold anomalies are linked to variable combinations of freshwater pulses, low total solar irradiance, explosive and effusive volcanism, and internal modes of climate variability, with cooling likely sustained by ocean/sea-ice feedbacks. The climate evolution reflected by our glacial and organic proxy records corresponds closely to marine records from the North Iceland Shelf.

  7. Reproduction rates under variable food conditions and starvation in Mnemiopsis leidyi: significance for the invasion success of a ctenophore

    DEFF Research Database (Denmark)

    Jaspers, Cornelia; Møller, Lene Friis; Kiørboe, Thomas

    2015-01-01

    Europe. Furthermore, starved animals continue to produce eggs for up to 12 days after cessation of feeding with high overall hatching success of 65–90%. These life history traits allow M. leidyi to thrive and reproduce in environments with varying food conditions and give it a competitive advantage under...... on the reproduction of laboratory-reared and field-caught animals during starvation. Our results show that the half-saturation zooplankton prey concentration for egg production is reached at food levels of 12–23 µgC L−1, which is below the average summer food concentration encountered in invaded areas of northern...... unfavourable conditions. This may explain why recurrent population blooms are observed and sustained in localized areas in invaded northern Europe, where water exchange is limited and zooplankton food resources are quickly depleted by M. leidyi. We suggest that these reproductive life history traits are key...

  8. Analytical constraints on layered gas trapping and smoothing of atmospheric variability in ice under low-accumulation conditions

    Directory of Open Access Journals (Sweden)

    K. Fourteau

    2017-12-01

    Full Text Available We investigate for the first time the loss and alteration of past atmospheric information from air trapping mechanisms under low-accumulation conditions through continuous CH4 (and CO measurements. Methane concentration changes were measured over the Dansgaard–Oeschger event 17 (DO-17,  ∼  60 000 yr BP in the Antarctic Vostok 4G-2 ice core. Measurements were performed using continuous-flow analysis combined with laser spectroscopy. The results highlight many anomalous layers at the centimeter scale that are unevenly distributed along the ice core. The anomalous methane mixing ratios differ from those in the immediate surrounding layers by up to 50 ppbv. This phenomenon can be theoretically reproduced by a simple layered trapping model, creating very localized gas age scale inversions. We propose a method for cleaning the record of anomalous values that aims at minimizing the bias in the overall signal. Once the layered-trapping-induced anomalies are removed from the record, DO-17 appears to be smoother than its equivalent record from the high-accumulation WAIS Divide ice core. This is expected due to the slower sinking and densification speeds of firn layers at lower accumulation. However, the degree of smoothing appears surprisingly similar between modern and DO-17 conditions at Vostok. This suggests that glacial records of trace gases from low-accumulation sites in the East Antarctic plateau can provide a better time resolution of past atmospheric composition changes than previously expected. We also developed a numerical method to extract the gas age distributions in ice layers after the removal of the anomalous layers based on comparison with a weakly smoothed record. It is particularly adapted for the conditions of the East Antarctic plateau, as it helps to characterize smoothing for a large range of very low-temperature and low-accumulation conditions.

  9. Optimal design of structures with multiple design variables per group and multiple loading conditions on the personal computer

    Science.gov (United States)

    Nguyen, D. T.; Rogers, J. L., Jr.

    1986-01-01

    A finite element based programming system for minimum weight design of a truss-type structure subjected to displacement, stress, and lower and upper bounds on design variables is presented. The programming system consists of a number of independent processors, each performing a specific task. These processors, however, are interfaced through a well-organized data base, thus making the tasks of modifying, updating, or expanding the programming system much easier in a friendly environment provided by many inexpensive personal computers. The proposed software can be viewed as an important step in achieving a 'dummy' finite element for optimization. The programming system has been implemented on both large and small computers (such as VAX, CYBER, IBM-PC, and APPLE) although the focus is on the latter. Examples are presented to demonstrate the capabilities of the code. The present programming system can be used stand-alone or as part of the multilevel decomposition procedure to obtain optimum design for very large scale structural systems. Furthermore, other related research areas such as developing optimization algorithms (or in the larger level: a structural synthesis program) for future trends in using parallel computers may also benefit from this study.

  10. Gene expression in response to Cotton Leaf Curl Virus infection in Gossypium hirsutum under variable environmental conditions

    Directory of Open Access Journals (Sweden)

    Rehman Iqra

    2017-01-01

    Full Text Available Cotton Leaf Curl Disease (CLCuD is one of the threatening constrains of cotton production in Pakistan for which no adequate remedy is available until now. Local variety of Gossypium hirsutum (FH-142 was grown in field and infected naturally by CLCuV under variable range of temperature and humidity. Plants showed thickening of veins in lower leaf surface at 34°C and 60% relative humidity at 15days post infection (dpi and curling of leaf margins at 33°C with 58% relative humidity at 30dpi. Remarkable leaf darkening was observed with reduced boll formation at 45dpi at 26°C and 41% relative humidity. Enation developed, severe thickening and curling of leaves intensified and plants showed dwarf growth at 60dpi at 24°C with 52% relative humidity. PCR amplification of Rep associated gene confirmed the presence of CLCuD-associated begomovirus in the infected samples. Quantitative RT-PCR confirmed the amplification and differential expression of a number of pathogen stress responsive genes at different levels of temperature and humidity. This observation predicts that Cotton Leaf Curl Virus (CLCuV interacts with several host genes that are upregulated to make plants susceptible or suppress other genes to overcome host defense responses.

  11. Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

    Science.gov (United States)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

  12. Improvement in simulation of Eurasian winter climate variability with a realistic Arctic sea ice condition in an atmospheric GCM

    International Nuclear Information System (INIS)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988–2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to ∼0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated. (letter)

  13. Competition between autotrophic and heterotrophic microbial plankton for inorganic nutrients induced by variability in estuarine biophysicochemical conditions

    Science.gov (United States)

    Williams, A.; Quigg, A.

    2016-02-01

    Competition for inorganic nutrients between autotrophic and heterotrophic fractions of microbial plankton (0.2-20μm) was investigated at two stations in a sub-tropical estuary, Galveston Bay, Texas. Competition potential between these groups is enhanced because individuals are similar in size, reducing variability among their nutrient uptake efficiencies. Further, in estuaries, allochthonous supplements to autochthonous carbon may satisfy heterotrophic requirements, allowing alternative factors to limit abundance. The relative abundance of autotrophs and heterotrophs stained with SYBR Green I and enumerated on a Beckman Coulter Gallios flow cytometer were evaluated monthly during a year-long study. Shifts in the relative in situ abundance were significantly related to temperature, dissolved inorganic nitrogen (DIN), phosphorous (Pi), and total organic carbon (TOC) concentrations revealing opposing gradients of limitation by different abiotic factors. In corresponding in vitro nutrient enrichment bioassays the relative contribution of autotrophic or heterotrophic microbial plankton to significant enrichment responses varied. Only during macro- (>20μm) phytoplankton blooms do autotrophic microbial plankton respond to nutrient enrichment. Contrastingly, the heterotrophic microbial plankton responded to nutrient enrichment primarily when temperature limitation was alleviated. Therefore, the potential for autotrophic and heterotrophic microbial plankton competition for limiting nutrients is highest when autotrophic microbial plankton are also competing with larger phytoplankton during bloom events. Based on this evidence, we hypothesize that the autotrophic microbial fraction has a competitive advantage over the heterotrophs for inorganic nutrients in Galveston Bay. The observed microbial competition during estuarine phytoplankton blooms may have important consequences on biogeochemical processes including carbon and nutrient cycling.

  14. Updated analysis of flatfish recruitment response to climate variability and ocean conditions in the Eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, Thomas; Stockhausen, William; Bond, Nicholas

    2013-10-01

    This study provides a retrospective analysis of the relationship between physical oceanography, biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole (Hippoglossoides elassodon), northern rock sole (Lepidopsetta polyxystra), and arrowtooth flounder (Atheresthes stomias) during the period 1978-2005. Stock assessment model estimates of recruitment and spawning stock size indicate that temporal patterns in productivity are consistent with decadal scale (or shorter) patterns in climate variability, which may influence marine survival during the early life history phases. Density-dependence (through spawning stock size) was statistically significant in a Ricker stock-recruit model of flatfish recruitment that included environmental terms. Wind-driven advection of northern rock sole and flathead sole larvae to favorable nursery grounds was found to coincide with years of above-average recruitment. Ocean forcing of Bristol Bay surface waters during springtime was mostly on-shelf (eastward) during the 1980s and again in the early 2000s, but was off-shelf (westerly) during the 1990s, corresponding with periods of good and poor recruitment, respectively. Finally, the Arctic Oscillation was found to be an important indicator of arrowtooth flounder productivity. Model results were applied to IPCC (Intergovernmental Panel on Climate Change) future springtime wind scenarios to predict the future impact of climate on northern rock sole productivity and indicated that a moderate future increase in recruitment might be expected because the climate trends favor on-shelf transport but that density-dependence will dampen this effect such that northern rock sole abundance will not be substantially affected by climate change.

  15. Assessment of process variables on the use of macauba pulp oil as feedstock for the continuous production of ethyl esters under pressurized conditions

    Directory of Open Access Journals (Sweden)

    T. A. da S. Colonelli

    Full Text Available ABSTRACT This study evaluated the potential of macauba pulp oil (MPO as a feedstock for continuous ester production using ethanol under pressurized conditions. Experiments were performed in order to obtain data for the effect of process variables on ethyl ester (FAEE and free fatty acid (FFA conversion in a catalyst-free process. From the results, it appears that the MPO to ethanol mass ratio and the pressure were the variables with more favorable effect on the evaluated response variables. The addition of n-hexane caused an increase in the production of esters; however, this had a negative effect on FFA conversion. The addition of water was unfavorable for oil processing with high acidity. In this process, esterification and transesterification occur simultaneously, and the high FFA content in MPO provides high yields (85 wt% of esters; 93% FFA conversion at low temperature, since the esterification reaction rate is higher than the transesterification. The decomposition of fatty acids was evaluated and levels <5% were observed under the evaluated experimental conditions.

  16. Summary report of bioassays for the city of Hollywood water plant membrane reject water as it mixed with WWTP effluent in an ocean outfall environment

    Energy Technology Data Exchange (ETDEWEB)

    Fergen, R.E.; Vinci, P.; Bloetscher, F.

    1999-07-01

    A special bioassay study was conducted to review the impact of the City of Hollywood's Membrane Softening Water Treatment Plant (WRP) reject water as it mixes with the City's Wastewater Treatment Plant (WWTP) effluent. Three sampling periods occurred during 1997. The purpose of this study was to determine potential toxicity of the WTP reject water, pre-chlorinated effluent, and combined effluent, and to demonstrate if the combined effluent was acceptable for ocean discharge on the basis of no potential toxicity. Effluent was acceptable for ocean discharge on the basis of no potential toxicity. Effluent samples were collected at six sampling points; three were in the plant, while the other three were along the outfall pipeline. Definitive, static renewal bioassay tests were performed using Mysidopsis bahia and Menidia beryllina as indicators of potential toxicity. The bioassay tests at 30% effluent concentration indicate that there is not potential toxicity for the pre-chlorinated WTP effluent, WTP reject water, dechlorinate combined effluent at the plant, and chlorinated combined effluent at Holland Park, the riser, and the terminus. The results indicate that the WTP reject water (100%) is not toxic to Menidia beryllina but was toxic to Mysidopsis bahia. When combined with the WWRP effluent, the reject water's impact on the potential toxicity of the commingled effluent was insignificant. All of the tests indicate the combined effluents are not toxic to the species tested at the 30% effluent level. Therefore, potential toxicity concerns were not demonstrated for this outfall discharge and did not prevent FDEP from issuing a permit to the City of Hollywood for the disposal of the combined effluent. Furthermore, these results, in combination with the previous results, indicated that individual bioassay testing for the reject water for regulatory compliance is not required.

  17. Diurnal Variability of the inner-shelf circulation in the lee of a cape under upwelling conditions

    Science.gov (United States)

    Lamas, Luisa; Peliz, Álvaro; Marchesiello, Patrick

    2013-04-01

    The circulation over the inner-shelf is a key component of shelf dynamics and an important mechanism for cross-shore exchange on most shelves. Yet our understanding of the cross-shore circulation and how it depends on different forcing conditions, bathymetry and stratification remains poor due in part to sparse observations and the difficulty of resolving spatial and temporal scales within the inner-shelf. Most studies of cross-shore transport on the inner-shelf consider only a 2D circulation, due to coastal upwelling or downwelling and assume along-shore uniformity. However, divergence in the along-shore and cross-shore flows may occur with the presence of complex coastline topography or subtle bathymetric features, and can drive substantial horizontal cross-shore exchange, with same order of magnitude as coastal upwelling and downwelling. A recent study using observational data collected near cape Sines, Portugal, showed that not only wind, waves and tides are important forcing mechanisms of the inner-shelf circulation, but also that the along-shore pressure gradient plays a major role on driving cross-shore exchange. A modeling study was conducted in order to study the complexity of the inner-shelf dynamics, in the presence of a cape. A simplified configuration was used in order to isolate the effects of individual processes: wind, heat fluxes, tides and waves. The preliminary results of the effects of these processes on the inner-shelf circulation will be presented.

  18. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Mahmood, Asif; Aziz, Asim; Jamshed, Wasim; Hussain, Sajid

    Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2 -water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary.

  19. The Impact of Different Habitat Conditions on the Variability of Wild Populations of a Medicinal Plant Betonica officinalis L.

    Directory of Open Access Journals (Sweden)

    Kinga Kostrakiewicz-Gierałt

    2015-06-01

    Full Text Available Plants are important source of beneficial bioactive compounds which may find various applications as functional ingredients, such as components of food supplements, cosmetics, and pharmaceuticals. One such medicinal plant is Betonica officinalis, populations of which were investigated in 2012‒13. The studies were conducted in patches of Molinietum caeruleae dominated by: small meadow taxa (patch I; the shrub willow Salix repens ssp. rosmarinifolia (patch II; large tussock grasses Deschampsia caespitosa and Molinia caerulaea (patch III; tall-growing macroforbs Filipendula ulmaria and Solidago canadensis (patch IV. Over successive patches, the average height of plant cover increased, as did soil moisture, while light availability at ground level decreased. Much greater abundance and density of the Betonica officinalis population were found in patches I, III and IV, while lower values for these parameters were noted in patch II. Individuals in pre-reproductive stages were absent during whole study period in all study plots, vegetative ramet clusters were observed in plots situated in patches I and III in the first year of observations, while only generative ramet clusters occurred in plots set in patches II and IV. The number of rosettes per ramet cluster, number and dimensions of rosette leaves, height of flowering stems, number of cauline leaves, length of inflorescences, as well as number and length of flowers increased gradually over successive patches, whereas the number of generative stems per ramet cluster did not differ remarkably among populations. On the basis of the performed studies it might be concluded that the condition of populations deteriorated from patches overgrown by large-tussock grasses and characterized by considerable share of native and alien tall-growing macroforbs, via patch dominated by small meadow taxa, to patch prevailed by shrub willows.

  20. Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

    Science.gov (United States)

    Siddon, Elizabeth Calvert; Kristiansen, Trond; Mueter, Franz J; Holsman, Kirstin K; Heintz, Ron A; Farley, Edward V

    2013-01-01

    Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included local predator and prey energy densities, and (2) an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting recruitment variability.

  1. Month-to-month variability of Indian summer monsoon rainfall in 2016: role of the Indo-Pacific climatic conditions

    Science.gov (United States)

    Chowdary, Jasti S.; Srinivas, G.; Du, Yan; Gopinath, K.; Gnanaseelan, C.; Parekh, Anant; Singh, Prem

    2018-03-01

    -Western Pacific circulation anomalies in August 2016 are well predicted when the coupled model is initiated with initial conditions from end of July and beginning of August compared to May. This analysis suggests the importance of the WNP circulation in forcing strong sub-seasonal/month to month rainfall variations over India.

  2. Analysis of Direct Outdoor Air Cooling Efficency for Combined Variable Air Volume Air-conditioning System in Stores in Cold Climates of China

    OpenAIRE

    Luo, Zhiwen

    2006-01-01

    Direct outdoor air cooling contributes a lot not only to the improvement of the indoor air quality but also to the energy saving. Its full use will reduce the water chiller’s running time especially in some stores where cooling load keeps much higher and longer than that in other buildings. A novel air-conditioning system named Combined Variable Air Volume system (CVAV), combining a normal AHU with a separate outdoor air supply system, was proposed firstly by the authors. The most attractive ...

  3. Influence of Variable Thermal Conductivity on MHD Boundary Layer Slip Flow of Ethylene-Glycol Based Cu Nanofluids over a Stretching Sheet with Convective Boundary Condition

    Directory of Open Access Journals (Sweden)

    N. Bhaskar Reddy

    2014-01-01

    Full Text Available An analysis is carried out to investigate the influence of variable thermal conductivity and partial velocity slip on hydromagnetic two-dimensional boundary layer flow of a nanofluid with Cu nanoparticles over a stretching sheet with convective boundary condition. Using similarity transformation, the governing boundary layer equations along with the appropriate boundary conditions are transformed to a set of ordinary differential equations. Employing Runge-kutta fourth-order method along with shooting technique, the resultant system of equations is solved. The influence of various pertinent parameters such as nanofluid volume fraction parameter, the magnetic parameter, radiation parameter, thermal conductivity parameter, velocity slip parameter, Biot number, and suction or injection parameter on the velocity of the flow field and heat transfer characteristics is computed numerically and illustrated graphically. The present results are compared with the existing results for the case of regular fluid and found an excellent agreement.

  4. Temporal variability of the quality of Taraxacum officinale seed progeny from the East-Ural radioactive trace: is there an interaction between low level radiation and weather conditions?

    Science.gov (United States)

    Pozolotina, Vera N; Antonova, Elena V

    2017-03-01

    The multiple stressors, in different combinations, may impact differently upon seed quality, and low-level doses of radiation may enhance synergistic or antagonistic effects. During 1991-2014 we investigated the quality of the dandelion (Taraxacum officinale s.l.) seed progeny growing under low-level radiation exposure at the East-Ural Radioactive Trace (EURT) area (result of the Kyshtym accident, Russia), and in plants from areas exposed to background radiation. The viability of the dandelion seed progeny was assessed according to chronic radiation exposure, accounting for the variability of weather conditions among years. Environmental factors (temperature, precipitation, and their ratio in different months) can modify the radiobiological effects. We found a wide range of possible responses to multiple stressors: inhibition, stimulation, and indifferent effects in different seasons. The intraspecific variability of the quality of dandelion seed progeny was greatly increased under conditions of low doses of chronic irradiation. Temperature was the most significant factor for seed progeny formation in the EURT zone, whereas the sums of precipitation and ratios of precipitation to temperature dominantly affected organisms from the background population.

  5. Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

    International Nuclear Information System (INIS)

    Wang, P.-Y.; Hou, S.-S.

    2005-01-01

    In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

  6. Leaf area index estimation in a pine plantation with LAI-2000 under direct sunlight conditions: relationship with inventory and hydrologic variables

    International Nuclear Information System (INIS)

    Molina, A.; Campo, A. D. del

    2011-01-01

    LAI is a key factor in light and rainfall interception processes in forest stands and, for this reason, is called to play an important role in global change adaptive silviculture. Therefore, it is necessary to develop practical and operative methodologies to measure this parameter as well as simple relationships with other silviculture variables. This work has studied 1) the feasibility of LAI-2000 sensor in estimating LAI-stand when readings are taken under direct sunlight conditions; and 2) the ability of LAI in studying rainfall partitioned into throughfall (T) in an Aleppo pine stand after different thinning intensities, as well as its relationships to basal area, (G), cover (FCC), and tree density (D). Results showed that the angular correction scheme applied to LAI-2000 direct-sunlight readings stabilized them for different solar angles, allowing a better operational use of LAI-2000 in Mediterranean areas, where uniform overcast conditions are difficult to meet and predict. Forest cover showed the highest predictive ability of LAI (R 2 = 0.98; S = 0.28), then G (R 2 = 0.96; S = 0.43) and D (R 2 = 0.50; S = 0.28). In the hydrological plane, T increased with thinning intensity, being G the most explanatory variable (R 2 = 0.81; S = 3.07) and LAI the one that showed the poorest relation with it (R 2 = 0.69; S = 3.95). These results open a way for forest hydrologic modeling taking LAI as an input variable either estimated form LAI-2000 or deducted from inventory data. (Author) 36 refs.

  7. Effect modification of the association between meteorological variables and mortality by urban climatic conditions in the tropical city of Kaohsiung, Taiwan

    Directory of Open Access Journals (Sweden)

    William B. Goggins

    2013-11-01

    Full Text Available A deeper understanding of extreme hot weather are needed in cities sensitive to heat effects, an investigation was done in the tropical town of Kaohsiung in Taiwan. Its 11 districts were divided into three climatic classes varying from high urban heat, low levels of green space and lack of proximity to water bodies to low urban heat, adequate green space and proximity to water bodies. Daily data on natural mortality, meteorological variables, and pollutants from May-October 1999-2008 were analysed using generalised additive models for the time-series data. Subgroup analyses were conducted, stratifying decedents according to the level of planning activity required in order to mitigate adverse heat effects in their residential areas, classifying districts as “level 1” for those requiring a high level of mitigation action; “level 2” for those requiring some action; and “level 3” for those that need only preserve existing conditions. Stratified analyses showed that mortality increases per 1 °C rise on average, either on the same day or in the previous 4 days (lags 0-4, were associated with 2.8%, 2.3% and -1.3% for level 1, 2 and 3 districts, respectively. The slope describing the association between temperature and mortality was higher above 29.0 °C resulting in corresponding increases of 4.2%, 5.0% and 0.3% per per 1 °C rise in temperature, respectively. Other meteorological variables were not significantly associated with mortality. It is concluded that hot season mortality in Kaohsiung is only sensitive to heat effects in districts classified as having unfavourably climatic conditions and requiring mitigation efforts in city planning. Urban planning measures designed to improve climatic conditions could reduce excess mortality resulting from extreme hot weather.

  8. Interannual variability in the extent and intensity of tropical dry forest deciduousness in the Mexican Yucatan (2000-2016): Drivers and Links to Regional Atmospheric Conditions

    Science.gov (United States)

    Cuba, Nicholas Joseph

    The dry topical forests of the southern Yucatan Peninsula experience multiple natural and anthropogenic disturbances, as well as substantial interannual climate variability that can result in stark interannual differences in vegetation phenology. Dry season deciduousness is a typical response to limit tree water loss during prolonged periods of hot and dry conditions, and this behavior has both direct implications for ecosystem functioning, and the potential to indicate climate conditions when observed using remotely-sensed data. The first research paper of this dissertation advances methods to assess the accuracy of remotely-sensed measurements of canopy conditions using in-situ observations. Linear regression models show the highest correlation (R2 = 0.751) between in-situ canopy gap fraction and Landsat NDWISWIR2. MODIS time series NDWISWIR2 are created for the period March 2000-February 2011, and exhibit stronger correlation with time series of TRMM precipitation data than do MODIS EVI time series (R2= 0.48 vs. R2 = 0.43 in deciduous forest areas). The second paper examines differences between the deciduous phenology of young forest stands and older forest stands. Land-cover maps are overlaid to determine whether forested areas are greater than or less than 22 years old in 2010, and metrics related to deciduous phenology are derived from MODIS EVI2 time series in three years, 2008 to 2011. Statistical tests that compare matched pairs of young (12-22 years) and older (>22 years) forest stand age class samples are used to detect significant differences in metrics related to the intensity and timing of deciduousness. In all three years, younger forests exhibit significantly more intense deciduousness, measured as total seasonal change of EVI2 normalized by annual maximum EVI2 (pmediating environmental factors that drive the spatial and temporal variability in the intensity of deciduousness, and point toward analyzing deciduousness to reveal information about other

  9. Model aerodynamic test results for two variable cycle engine coannular exhaust systems at simulated takeoff and cruise conditions. [Lewis 8 by 6-foot supersonic wind tunnel tests

    Science.gov (United States)

    Nelson, D. P.

    1980-01-01

    Wind tunnel tests were conducted to evaluate the aerodynamic performance of a coannular exhaust nozzle for a proposed variable stream control supersonic propulsion system. Tests were conducted with two simulated configurations differing primarily in the fan duct flowpaths: a short flap mechanism for fan stream control with an isentropic contoured flow splitter, and an iris fan nozzle with a conical flow splitter. Both designs feature a translating primary plug and an auxiliary inlet ejector. Tests were conducted at takeoff and simulated cruise conditions. Data were acquired at Mach numbers of 0, 0.36, 0.9, and 2.0 for a wide range of nozzle operating conditions. At simulated supersonic cruise, both configurations demonstrated good performance, comparable to levels assumed in earlier advanced supersonic propulsion studies. However, at subsonic cruise, both configurations exhibited performance that was 6 to 7.5 percent less than the study assumptions. At take off conditions, the iris configuration performance approached the assumed levels, while the short flap design was 4 to 6 percent less.

  10. Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Aziz, Asim; Jamshed, Wasim; Aziz, Taha

    2018-04-01

    In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The non-Newtonian Maxwell nanofluid model is utilized for the working fluid along with slip and convective boundary conditions and comprehensive analysis of entropy generation in the system is also observed. The effect of thermal radiation and variable thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for Cu-water and TiO2-water nanofluids. Results are presented for the velocity, temperature and entropy generation profiles, skin friction coefficient and Nusselt number. The discussion is concluded on the effect of various governing parameters on the motion, temperature variation, entropy generation, velocity gradient and the rate of heat transfer at the boundary.

  11. Remaining Sites Verification Package for the 116-F-8, 1904-F Outfall Structure and the 100-F-42, 1904-F Spillway. Attachment to Waste Site Reclassification Form 2006-038 and 2006-045

    International Nuclear Information System (INIS)

    Dittmer, L.M.

    2006-01-01

    The 116-F-8 waste site is the former 1904-F Outfall Structure used to discharge reactor cooling water effluent from the 107-F Retention Basin to the Columbia River. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  12. Magnetic studies of archaeological obsidian: Variability of eruptive conditions within obsidian flows is key to high-resolution artifact sourcing (Invited)

    Science.gov (United States)

    Feinberg, J. M.; Frahm, E.; Muth, M.

    2013-12-01

    Previous studies have endeavored to use petrophysical traits of obsidian, particularly its magnetic properties, as an alternative to conventional geochemical sourcing, one of the greatest successes in archaeological science. Magnetic approaches, however, have not seen widespread application due to their mixed success. In a time when geochemical analyses can be conducted non-destructively, in the field, and in a minute or two, magnetic measurements of obsidian must offer novel archaeological insights to be worthwhile, not merely act as a less successful version of geochemistry. To this end, we report the findings of a large-scale study of obsidian magnetism, which includes 912 geological obsidian specimens and 97 artifacts measured for six simple magnetic parameters. Based on these results, we propose, rather than using magnetic properties to source artifacts to a particular obsidian flow (inter-flow sourcing), these properties are best used to differentiate quarrying sites within an individual flow (intra-flow sourcing). The magnetic properties within an individual flow are highly variable, due to the fact that a single flow experiences a wide array of cooling rates, absolute temperatures, viscosities, deformation, and oxidation. These conditions affect the concentrations, compositions, size distributions, shapes, and spatial arrangements of magnetic grains within an obsidian specimen and, thus, its intrinsic magnetic properties. This variability decreases dramatically at spatial scales of individual outcrops, and decreases even further at scales of hand samples. Thus, magnetic data appear to shift the scale of obsidian sourcing from flows to quarries and, in turn, enable new insights into raw-material procurement strategies, group mobility, lithic technology, and the organization of space and production. From a geologic perspective, the magnetic variability of obsidian can be broadly interpreted within the context of the igneous processes that were active during

  13. Effect of beam condition in variable-shaped electron-beam direct writing for 0.25 μm and below

    International Nuclear Information System (INIS)

    Hirasawa, S.; Nakajima, K.; Tamura, T.; Aizaki, N.

    1993-01-01

    The effect of incident electron-beam conditions, which are acceleration voltage and beam blur of variable-shaped electron-beam direct writing, is investigated using the deposited energy distribution to realize a fine pattern of ≤0.25 μm in trilayer resist process. The deposited energy distribution is calculated using a three-dimensional Monte Carlo method. In a trilayer resist system, a thin bottom resist layer can be used, because the contrast value derived from the Monte Carlo calculation is independent of the bottom layer thickness. The beam blur of 0.05 μm does not degrade 0.25 μm line-and-space (L/S) patterns, but seriously degrades 0.1 μm L/S patterns. Higher acceleration voltage is effective for improving the contrast. At lower acceleration voltage, the slope of the deposited energy profile defined at the resist bottom is mainly influenced by electron scattering. On the other hand, at higher acceleration voltage, the slope of deposited energy profile mainly depends on the beam blur. The 0.1 μm L/S patterns are expected to be resolved at 30 kV when there is less than 0.02 μm beam blur with trilayer resist system. The possibility of using a single layer resist process for 0.1 μm L/S pattern will be barely realized at the conditions of 50 kV and 0.02 μm beam blur

  14. Distinguishing the impacts of human activities and climate variability on runoff and sediment load change based on paired periods with similar weather conditions

    NARCIS (Netherlands)

    Wang, Fei; Hessel, Rudi; Mu, Xingmin; Maroulis, Jerry; Zhao, Guangju; Geissen, Violette; Ritsema, Coen

    2015-01-01

    Runoff and sediment loads from river basin are largely affected by the interplay of climate variability and human activities within the basin. However, distinguishing the impacts of climate variability and human activities would vastly improve our knowledge of water resources, climate variability

  15. Study of Stage-wise Pressure Pulsation in an Electric Submersible Pump under Variable Frequency Operation at Shut-off Condition

    Science.gov (United States)

    Dhanasekaran, A.; Kumaraswamy, S.

    2018-01-01

    Pressure pulsation causes vibration in the Electric Submersible Pump (ESP) and affects the life and performance of its system. ESP systems are installed at depths ranging from a few meters to several hundred meters. Unlike pumps used on the surface, once they are installed they become inaccessible for maintenance or for any kind of diagnostic measurement that might be taken directly on them. Therefore a detailed knowledge of mean and fluctuating pressures is required to achieve an optimal pressure distribution inside the ESP. This paper presents the results of an experimental investigation of the stage-wise pulsating pressure in ESP at shut-off condition at different speeds. Experiments were conducted on a pump having five stages. A variable frequency drive was used to operate the pump at five different speeds. Piezoresistive transducers were mounted at each stage of ESP to capture the unsteady pressure signals. Fast Fourier Transformation was carried out on the pressure signals to convert into frequency domain and the spectra of pressure pulsation signals were analyzed. The obtained results indicated the existence of fundamental frequency corresponding to the speed of rotation times the number of impeller blades and of the whole series of harmonics of higher frequencies.

  16. Variability of the morphometric features of Calliphora vicina (Diptera, Calliphoridae under the varying and constant micro-climatic condi-tions

    Directory of Open Access Journals (Sweden)

    L. I. Faly

    2013-03-01

    Full Text Available Variability of the main morphometric features of imago flies Calliphora vicina R.-D. (Diptera, Calliphoridae of two samples was studied. First sample consists of individuals caught in the wild (park ecosystems of Dnipropetrovsk, the second one – specimens cultured in the laboratory under the constant temperature and humidity. Possible using of C. vicina R.-D. as a bioindicator of anthropogenic factors is analysed. Environmental factors may act as the stimulators of adaptive changes in physiological functions, as the constraints that cause impossibility of the existence of certain species in particular conditions, and as modifiers that determine the morpho- anatomical and physiological changes in organisms. The most significant differences between studied samples were found for the width (“laboratory” individuals are characterized by larger head size and for the length of limbs segments. The fluctuating range of the head width in specimens collected in the wild is much wider, due to the heterogeneity of the micro-climatic conditions of the larvae development and trophic resources. Maximal negative asymmetry of the head width is observed in individuals C. vicina R.-D. of the “natural” sample as compared with “laboratory” individuals. Among imagoes caught in the wild the individuals with a relatively wide head are dominated, as evidenced by the large positive value of kurtosis. At the same time, the distribution of values in “laboratory” individuals is almost normal. In adults bred in the laboratory the shortening of segments of the leg pair I is observed in comparison with the individuals of “natural” sample. Similar results were recorded for other insect groups cultivated in a laboratory. For most other linear measurements of the C. vicina R.-D. body the differences between samples are not registered. Ephemeral existence of the substrate of blow flies leads to higher prevailing evolutionary adaptation of species to varying

  17. Conservadorismo condicional: estudo a partir de variáveis econômicas Conditional conservatism: a study based on economic variables

    Directory of Open Access Journals (Sweden)

    Rafael de Lacerda Moreira

    2010-12-01

    usefulness of that information. Conditional Conservatism is linked to the trend for accounting to require a higher degree of good news verification before disclosing it in the income when compared with the degree of bad news verification. In view of concerns with accounting information quality, this article aims to review the reflection of Conditional Conservatism in accounting income, based on economic variables. The study uses the Reverse Model of Associated Profit to Returns (BASU, 1997 and the model proposed by Kahn and Watts (2009, which examine the relation between accounting profit variables and economic return, using positive and negative returns as a proxy for good and bad news, and other variables widely accepted for the evaluation of conservatism. Therefore, statistical models were estimated for a sample of 96 companies from 2005 to 2007, based on annual information available in Economática® and data reported in explanatory notes. To select an economic event that may influence the asymmetric recognition of economic income, the researchers decided to compare results between companies listed on Bovespa's governance levels and other companies. The obtained results confirm the hypothesis on the use of conditional conservatism among sample companies for income measurement purposes. The positive differences in the degree of conservatism for companies adhering to governance levels are not conclusive, as the models showed scattered results. The economic variables offer advantages when the bad news may not be as clearly visible in the financial statements, which may reduce expected future results.

  18. Assessing temporal and spatial variability of phytoplankton composition in a large reservoir in the Brazilian northeastern region under intense drought conditions

    Directory of Open Access Journals (Sweden)

    Hortência de Souza Barroso

    2017-11-01

    Full Text Available The present study was carried out in Castanhão Reservoir, a large aquatic system in the Brazilian semi-arid region that serves multiples uses as water drinking supply and intensive fish-cage aquaculture site. In order to understand the effects of environmental conditions on the spatial and temporal variability of the phytoplankton functional groups (FG and the main ‘characterizing taxa’, sub-superficial water samples were collected from March 2012 to August 2013, a period distinguished by the continuous drop in reservoir volume due to rainfall shortage. Eighteen functional groups and 102 total phytoplankton taxa were found in the Castanhão reservoir during the study. No significant differences were observed relative to spatial variation of total phytoplankton composition throughout the reservoir (PERMANOVA, P>0.05. On the other hand, according to cluster analysis results, three temporal phases have been identified (Similarity Profile, P<0.05, based on 102 phytoplankton taxa. The ‘characterizing taxa’ was found using the Similarity Percentage procedure (cut-off 90%, being thus defined as those taxa that contributed the most to the similarity within each temporal phase. Nineteen ‘characterizing taxa’ described the Castanhão reservoir, with predominance of those typical of mixing and turbidity conditions. Cyanobacteria dominated through the three temporal phases. According to the redundancy analysis, nutrient availability and water transparency were found to influence the phytoplankton temporal dynamics. The phase I (rainy season was most represented by Planktolyngbya minor/Pl. limnetica (FG = S1, which reached best performance under strongly decreased phosphate-P concentrations and low water transparency. In phase II (dry season, Romeria victoriae (FG = ? outcompeted other cyanobacteria probably due the increase in water transparency and decrease in ammonium-N. Finally, in phase III (rainy season the decrease of water transparency

  19. 变温环境室空调系统实验研究%Experimental Study on Air Conditioning System of Variable Temperature Ambient Chamber

    Institute of Scientific and Technical Information of China (English)

    张柱; 吴蔚兰

    2017-01-01

    This paper introduces experimental facilities on air conditioning system of variable temperature ambient chamber.Researching and analysis the operating parameters of temperature distribution,compressor start-stop cycle and cooling capacity and COP changes.The results showed that the closer chamber controlled temperature is located to the ambient temperature,the smaller the temperature fluctuations is,temperature difference is also smaller;compared with the theoretical value,with ambient chamber temperature rising,compressor cooling capacity and COP rise;theoretical cooling capacity is more than the actual cooling capacity and compression of the start-stop,regardless of the theoretical value or experimental values,showed a downward trend from low to high,but the low temperature test values close to the theoretical value,when the high temperature is lower than the theoretical value.%介绍了变温环境室空调系统实验装置,研究分析了不同工况下室内温度分布、压缩机启停周期、制冷量及COP等运行参数的变化情况.实验结果表明:室内控制温度越接近坐落环境温度,温度波动幅度越小,不同位置的温差也越小;与理论值相比,压缩机的制冷量及COP随环境室温度升高而升高,理论制冷量大于实际制冷量;而压缩机启停比,无论理论值还是实验值,均呈现从低温到高温下降的趋势,但低温时实验值接近于理论值,高温时低于理论值.

  20. Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.

    Directory of Open Access Journals (Sweden)

    Ralf Lauterbach

    Full Text Available Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008-2010 in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming.

  1. V S30, slope, H 800 and f 0: performance of various site-condition proxies in reducing ground-motion aleatory variability and predicting nonlinear site response

    Science.gov (United States)

    Derras, Boumédiène; Bard, Pierre-Yves; Cotton, Fabrice

    2017-09-01

    The aim of this paper is to investigate the ability of various site-condition proxies (SCPs) to reduce ground-motion aleatory variability and evaluate how SCPs capture nonlinearity site effects. The SCPs used here are time-averaged shear-wave velocity in the top 30 m ( V S30), the topographical slope (slope), the fundamental resonance frequency ( f 0) and the depth beyond which V s exceeds 800 m/s ( H 800). We considered first the performance of each SCP taken alone and then the combined performance of the 6 SCP pairs [ V S30- f 0], [ V S30- H 800], [ f 0-slope], [ H 800-slope], [ V S30-slope] and [ f 0- H 800]. This analysis is performed using a neural network approach including a random effect applied on a KiK-net subset for derivation of ground-motion prediction equations setting the relationship between various ground-motion parameters such as peak ground acceleration, peak ground velocity and pseudo-spectral acceleration PSA ( T), and M w, R JB, focal depth and SCPs. While the choice of SCP is found to have almost no impact on the median ground-motion prediction, it does impact the level of aleatory uncertainty. V S30 is found to perform the best of single proxies at short periods ( T < 0.6 s), while f 0 and H 800 perform better at longer periods; considering SCP pairs leads to significant improvements, with particular emphasis on [ V S30- H 800] and [ f 0-slope] pairs. The results also indicate significant nonlinearity on the site terms for soft sites and that the most relevant loading parameter for characterising nonlinear site response is the "stiff" spectral ordinate at the considered period.[Figure not available: see fulltext.

  2. Quantifying human disturbance in watersheds: Variable selection and performance of a GIS-based disturbance index for predicting the biological condition of perennial streams

    Science.gov (United States)

    Falcone, James A.; Carlisle, Daren M.; Weber, Lisa C.

    2010-01-01

    Characterizing the relative severity of human disturbance in watersheds is often part of stream assessments and is frequently done with the aid of Geographic Information System (GIS)-derived data. However, the choice of variables and how they are used to quantify disturbance are often subjective. In this study, we developed a number of disturbance indices by testing sets of variables, scoring methods, and weightings of 33 potential disturbance factors derived from readily available GIS data. The indices were calibrated using 770 watersheds located in the western United States for which the severity of disturbance had previously been classified from detailed local data by the United States Environmental Protection Agency (USEPA) Environmental Monitoring and Assessment Program (EMAP). The indices were calibrated by determining which variable or variable combinations and aggregation method best differentiated between least- and most-disturbed sites. Indices composed of several variables performed better than any individual variable, and best results came from a threshold method of scoring using six uncorrelated variables: housing unit density, road density, pesticide application, dam storage, land cover along a mainstem buffer, and distance to nearest canal/pipeline. The final index was validated with 192 withheld watersheds and correctly classified about two-thirds (68%) of least- and most-disturbed sites. These results provide information about the potential for using a disturbance index as a screening tool for a priori ranking of watersheds at a regional/national scale, and which landscape variables and methods of combination may be most helpful in doing so.

  3. Seasonal and diurnal variability of essential oil and its components in Origanum onites L. grown in the ecological conditions of Çukurova

    Directory of Open Access Journals (Sweden)

    Kirpik, Muzaffer

    2005-12-01

    Full Text Available Turkish Oregano ( Origanum onites L. is one of the most commonly collected from nature as well as cultivated Origanum species in Turkey . In addition, Turkish Oregano is the most exported Origanum species from Turkey to the entire World. In this study, the seasonal and diurnal variability of the essential oil content in Origanum onites L. grown in the ecological conditions of Çukurova was studied from September 2000-August 2001. Monthly variability of the essential oil composition was also studied. The plant cuttings collected from the region were rooted in the greenhouse and transferred to the field in a split plot design with three replications. One year later from transplanting, fresh leaves from the top shoots were collected every week three times a day on Monday (at 08.00, 12.00 and 16.00 o'clock throughout the year. The content and composition of the essential oil were analysed in fresh leaf samples by hydrodistillation. The essential oil content changed according to the seasons and the hour of day. The highest essential oil content (% 1.92 was found in the post-flowering -at the beginning of the seed formation period in the afternoon harvests during the second half of June (40th week. The essential oil composition varied monthly and the highest value (% 73.65 of carvacrol, the main component of the essential oil, was obtained from the flowering period in MayEl orégano turco ( Origanum onites L. es uno de los más recolectados de la naturaleza así como la especie de orégano más cultivada en Turquía. Además es la especie de orégano más exportada desde Turquía a todo el mundo. En este trabajo se estudió la variabilidad estacional y diurna del contenido de aceite esencial de Origanum onites L. cultivado en las condiciones ecológicas de Çukurova desde Septiembre de 2000 a Agosto de 2001. Se estudió también la variabilidad mensual de la composición del aceite esencial. Los plantones recogidos en la región fueron plantados en un

  4. College Education and Wages in the U.K. : Estimating Conditional Average Structural Functions in Nonadditive Models with Binary Endogenous Variables

    NARCIS (Netherlands)

    Klein, T.J.

    2009-01-01

    Recent studies debate how the unobserved dependence between the monetary return to college education and selection into college can be characterized. This paper examines this question using British data. We develop a semiparametric local instrumental variables estimator for identified features of a

  5. A study of probabilistic fatigue crack propagation models in Mg Al Zn alloys under different specimen thickness conditions by using the residual of a random variable

    International Nuclear Information System (INIS)

    Choi, Seon Soon

    2012-01-01

    The primary aim of this paper was to evaluate several probabilistic fatigue crack propagation models using the residual of a random variable, and to present the model fit for probabilistic fatigue behavior in Mg Al Zn alloys. The proposed probabilistic models are the probabilistic Paris Erdogan model, probabilistic Walker model, probabilistic Forman model, and probabilistic modified Forman models. These models were prepared by applying a random variable to the empirical fatigue crack propagation models with these names. The best models for describing fatigue crack propagation models with these names. The best models for describing fatigue crack propagation models with these names. The best models for describing fatigue crack propagation models with these names. The best models vor describing fatigue crack propagation behavior in Mg Al Zn alloys were generally the probabilistic Paris Erdogan and probabilistic Walker models. The probabilistic Forman model was a good model only for a specimen with a thickness of 9.45mm

  6. Fluctuations in the large-scale atmospheric circulation and ocean conditions associated with the dominant modes of wintertime precipitation variability for the contiguous United States

    International Nuclear Information System (INIS)

    Mitchell, T.P.; Blier, W.

    1994-01-01

    The historical Climatic Division record of monthly- and seasonal-mean wintertime precipitation totals are analyzed to document the dominant patterns of precipitation variability for the contiguous United States. The analysis technique employed is the Rotated Principal Component analysis. Time series for the leading patterns are related to global sea-surface temperatures (SSTs), and to gridded surface and upper-air analyses for the Northern Hemisphere

  7. Analysis of morpho-agronomic and climatic variables in successive agricultural years provides novel information regarding the phenological cycle of Jatropha in conditions of the Brazilian cerrado.

    Science.gov (United States)

    Domiciano, Gisele P; Alves, Alexandre A; Laviola, Bruno G; Albrecht, Julio C

    2014-12-01

    Phenological studies can provide information that enables the understanding of the dynamics of plants and how these dynamics are related to the biotic and abiotic environment. In order to study the phenological phases of Jatropha during two agricultural years, agronomic and climatic variables, such as temperature and rainfall, were evaluated. Data for each variable in each year and each genotype were subjected to analysis of variance (ANOVA) and the differences were tested at 5% probability by F test. In addition, the correlation of growth behavior and reproductive development of two Jatropha accessions (CNPAE-102 and CNPAE-169) as a function of time elapsed after the start of the phenological cycle with climatic variables were analyzed through Pearson's correlation. It was found that: (i) the resuming of plant growth by producing new branches and flowers of both genotypes coincides with the start of the rainy season, (ii) the flowering may be related to the increase in temperature and rainfall; (iii) the number of inflorescences per plant and number of female flowers determine the number of green fruits, (iv) the environmental changes are responsible for the delimitation of phenophases; and finally that (v) the responses to phenological changes are genotype-dependent.

  8. Analysis of morpho-agronomic and climatic variables in successive agricultural years provides novel information regarding the phenological cycle of Jatropha in conditions of the Brazilian cerrado

    Directory of Open Access Journals (Sweden)

    GISELE P. DOMICIANO

    2014-12-01

    Full Text Available Phenological studies can provide information that enables the understanding of the dynamics of plants and how these dynamics are related to the biotic and abiotic environment. In order to study the phenological phases of Jatropha during two agricultural years, agronomic and climatic variables, such as temperature and rainfall, were evaluated. Data for each variable in each year and each genotype were subjected to analysis of variance (ANOVA and the differences were tested at 5% probability by F test. In addition, the correlation of growth behavior and reproductive development of two Jatropha accessions (CNPAE-102 and CNPAE-169 as a function of time elapsed after the start of the phenological cycle with climatic variables were analyzed through Pearson's correlation. It was found that: (i the resuming of plant growth by producing new branches and flowers of both genotypes coincides with the start of the rainy season, (ii the flowering may be related to the increase in temperature and rainfall; (iii the number of inflorescences per plant and number of female flowers determine the number of green fruits, (iv the environmental changes are responsible for the delimitation of phenophases; and finally that (v the responses to phenological changes are genotype-dependent.

  9. Determinants of endogenous analgesia magnitude in a diffuse noxious inhibitory control (DNIC) paradigm: do conditioning stimulus painfulness, gender and personality variables matter?

    Science.gov (United States)

    Granot, Michal; Weissman-Fogel, Irit; Crispel, Yonathan; Pud, Dorit; Granovsky, Yelena; Sprecher, Elliot; Yarnitsky, David

    2008-05-01

    Descending modulation of pain can be demonstrated psychophysically by dual pain stimulation. This study evaluates in 31 healthy subjects the association between parameters of the conditioning stimulus, gender and personality, and the endogenous analgesia (EA) extent assessed by diffuse noxious inhibitory control (DNIC) paradigm. Contact heat pain was applied as the test stimulus to the non-dominant forearm, with stimulation temperature at a psychophysical intensity score of 60 on a 0-100 numerical pain scale. The conditioning stimulus was a 60s immersion of the dominant hand in cold (12, 15, 18 degrees C), hot (44 and 46.5 degrees C), or skin temperature (33 degrees C) water. The test stimulus was repeated on the non-dominant hand during the last 30s of the conditioning immersion. EA extent was calculated as the difference between pain scores of the two test stimuli. State and trait anxiety and pain catastrophizing scores were assessed prior to stimulation. EA was induced only for the pain-generating conditioning stimuli at 46.5 degrees C (p=0.011) and 12 degrees C (p=0.003). EA was independent of conditioning pain modality, or personality, but a significant gender effect was found, with greater EA response in males. Importantly, pain scores of the conditioning stimuli were not correlated with EA extent. The latter is based on both our study population, and on additional 82 patients, who participated in another study, in which EA was induced by immersion at 46.5 degrees C. DNIC testing, thus, seems to be relatively independent of the stimulation conditions, making it an easy to apply tool, suitable for wide range applications in pain psychophysics.

  10. Existence of solutions for a fourth order eigenvalue problem ] {Existence of solutions for a fourth order eigenvalue problem with variable exponent under Neumann boundary conditions

    Directory of Open Access Journals (Sweden)

    Khalil Ben Haddouch

    2016-04-01

    Full Text Available In this work we will study the eigenvalues for a fourth order elliptic equation with $p(x$-growth conditions $\\Delta^2_{p(x} u=\\lambda |u|^{p(x-2} u$, under Neumann boundary conditions, where $p(x$ is a continuous function defined on the bounded domain with $p(x>1$. Through the Ljusternik-Schnireleman theory on $C^1$-manifold, we prove the existence of infinitely many eigenvalue sequences and $\\sup \\Lambda =+\\infty$, where $\\Lambda$ is the set of all eigenvalues.

  11. Damage detection methodology under variable load conditions based on strain field pattern recognition using FBGs, nonlinear principal component analysis, and clustering techniques

    Science.gov (United States)

    Sierra-Pérez, Julián; Torres-Arredondo, M.-A.; Alvarez-Montoya, Joham

    2018-01-01

    Structural health monitoring consists of using sensors integrated within structures together with algorithms to perform load monitoring, damage detection, damage location, damage size and severity, and prognosis. One possibility is to use strain sensors to infer structural integrity by comparing patterns in the strain field between the pristine and damaged conditions. In previous works, the authors have demonstrated that it is possible to detect small defects based on strain field pattern recognition by using robust machine learning techniques. They have focused on methodologies based on principal component analysis (PCA) and on the development of several unfolding and standardization techniques, which allow dealing with multiple load conditions. However, before a real implementation of this approach in engineering structures, changes in the strain field due to conditions different from damage occurrence need to be isolated. Since load conditions may vary in most engineering structures and promote significant changes in the strain field, it is necessary to implement novel techniques for uncoupling such changes from those produced by damage occurrence. A damage detection methodology based on optimal baseline selection (OBS) by means of clustering techniques is presented. The methodology includes the use of hierarchical nonlinear PCA as a nonlinear modeling technique in conjunction with Q and nonlinear-T 2 damage indices. The methodology is experimentally validated using strain measurements obtained by 32 fiber Bragg grating sensors bonded to an aluminum beam under dynamic bending loads and simultaneously submitted to variations in its pitch angle. The results demonstrated the capability of the methodology for clustering data according to 13 different load conditions (pitch angles), performing the OBS and detecting six different damages induced in a cumulative way. The proposed methodology showed a true positive rate of 100% and a false positive rate of 1.28% for a

  12. Variabilidade espacial de atributos físicos do solo sob diferentes usos e manejos Spatial variability of physical attributes of soil under different use and management conditions

    Directory of Open Access Journals (Sweden)

    Eloiza G. S. Cavalcante

    2011-03-01

    Full Text Available O preparo de solo e as espécies vegetais têm expressivo efeito na variabilidade espacial do solo. Portanto, objetivou-se com este trabalho estudar a variabilidade espacial de alguns atributos físicos de um Latossolo Vermelho do cerrado do Mato Grosso do Sul, sob diferentes usos e manejos. O solo foi amostrado em uma malha, com intervalos regulares de 2,0 m, perfazendo o total de 64 pontos, nas profundidades de 0-0,10 m e 0,10-0,20 m para densidade do solo e nas profundidades de 0-0,15 m; 0,15-0,30 m; 0,30-0,45 m e 0,45-0,60 m para resistência do solo à penetração e teor de água no solo, em áreas com vegetação natural (cerrado, plantio direto, preparo convencional e pastagem. O maior coeficiente de variação e efeito pepita ocorreram para a resistência do solo à penetração. O sistema plantio direto apresentou maior alcance quando comparado com o do cerrado, preparo convencional e área com pastagem. As formas de uso e de manejo empregadas induziram, em ordem crescente, plantio direto, preparo convencional e pastagem à degradação dos atributos físicos do solo em relação ao cerrado.The soil tillage and the vegetable species have expressive effect on spatial variability of soil. The objective of this work was to study the spatial variability of some physical attributes of savannah soil (Oxisol of Mato Grosso do Sul, Brazil, under different management. The soil samples were collected in a grid, with regular intervals of 2.0 m, total of 64 points, in the depths of 0-0.10 m and 0.10-0.20 m for bulk density and in the depths 0-0.15 m; 0.15-0.30 m; 0.30-0.45 m and 0.45-0.60 m for the soil resistance to the penetration and soil water content, in the areas with native vegetation (savannah, no-tillage, conventional system and pasture. The greatest variability measured through the variation coefficient and nugget effect was observed for the soil resistance to penetration. The no-tillage showed major range when compared to native

  13. Exact solution for a two-phase Stefan problem with variable latent heat and a convective boundary condition at the fixed face

    Science.gov (United States)

    Bollati, Julieta; Tarzia, Domingo A.

    2018-04-01

    Recently, in Tarzia (Thermal Sci 21A:1-11, 2017) for the classical two-phase Lamé-Clapeyron-Stefan problem an equivalence between the temperature and convective boundary conditions at the fixed face under a certain restriction was obtained. Motivated by this article we study the two-phase Stefan problem for a semi-infinite material with a latent heat defined as a power function of the position and a convective boundary condition at the fixed face. An exact solution is constructed using Kummer functions in case that an inequality for the convective transfer coefficient is satisfied generalizing recent works for the corresponding one-phase free boundary problem. We also consider the limit to our problem when that coefficient goes to infinity obtaining a new free boundary problem, which has been recently studied in Zhou et al. (J Eng Math 2017. https://doi.org/10.1007/s10665-017-9921-y).

  14. The influence of variable operating conditions on the design and exploitation of fly ash pneumatic transport systems in thermal power plants

    Directory of Open Access Journals (Sweden)

    M. Stanojević

    2008-12-01

    Full Text Available The efficiency of an air-slide pneumatic conveying system depends, first of all, on several basic elements chosen or calculated during the design of a plant: air-slide design parameters, air mover characteristics, as well as the physical and chemical properties of the material to be transported. However, during the exploitation of this type of system which is used for handling ash in thermal-power plants, either gradual and/or sudden changes in the operating conditions can arise. This may be due to changes both in the proportion of ash content, and in the flow characteristics of the porous membrane. The consequences of changes in these conditions on the performance of the ash handling system are analyzed, based upon the results of the experimental work carried out on the test rig at the Faculty of Mechanical Engineering in Belgrade, and upon the on-site measurements at the thermal-power plant "Nikola Tesla B".

  15. Model aerodynamic test results for two variable cycle engine coannular exhaust systems at simulated takeoff and cruise conditions. Comprehensive data report. Volume 2: Tabulated aeroynamic data book 1

    Science.gov (United States)

    Nelson, D. P.

    1981-01-01

    Tabulated data from wind tunnel tests conducted to evaluate the aerodynamic performance of an advanced coannular exhaust nozzle for a future supersonic propulsion system are presented. Tests were conducted with two test configurations: (1) a short flap mechanism for fan stream control with an isentropic contoured flow splitter, and (2) an iris fan nozzle with a conical flow splitter. Both designs feature a translating primary plug and an auxiliary inlet ejector. Tests were conducted at takeoff and simulated cruise conditions. Data were acquired at Mach numbers of 0, 0.36, 0.9, and 2.0 for a wide range of nozzle operating conditions. At simulated supersonic cruise, both configurations demonstrated good performance, comparable to levels assumed in earlier advanced supersonic propulsion studies. However, at subsonic cruise, both configurations exhibited performance that was 6 to 7.5 percent less than the study assumptions. At takeoff conditions, the iris configuration performance approached the assumed levels, while the short flap design was 4 to 6 percent less. Data are provided through test run 25.

  16. Efficiency improvement of a spark-ignition engine at full load conditions using exhaust gas recirculation and variable geometry turbocharger – Numerical study

    International Nuclear Information System (INIS)

    Sjerić, Momir; Taritaš, Ivan; Tomić, Rudolf; Blažić, Mislav; Kozarac, Darko; Lulić, Zoran

    2016-01-01

    Highlights: • A cylinder model was calibrated according to experimental results. • A full cycle simulation model of turbocharged spark-ignition engine was made. • Engine performance with high pressure exhaust gas recirculation was studied. • Cooled exhaust gas recirculation lowers exhaust temperature and knock occurrence. • Leaner mixtures enable fuel consumption improvement of up to 11.2%. - Abstract: The numerical analysis of performance of a four cylinder highly boosted spark-ignition engine at full load is described in this paper, with the research focused on introducing high pressure exhaust gas recirculation for control of engine limiting factors such as knock, turbine inlet temperature and cyclic variability. For this analysis the cycle-simulation model which includes modeling of the entire engine flow path, early flame kernel growth, mixture stratification, turbulent combustion, in-cylinder turbulence, knock and cyclic variability was applied. The cylinder sub-models such as ignition, turbulence and combustion were validated by using the experimental results of a naturally aspirated multi cylinder spark-ignition engine. The high load operation, which served as a benchmark value, was obtained by a standard procedure used in calibration of engines, i.e. operation with fuel enrichment and without exhaust gas recirculation. By introducing exhaust gas recirculation and by optimizing other engine operating parameters, the influence of exhaust gas recirculation on engine performance is obtained. The optimum operating parameters, such as spark advance, intake pressure, air to fuel ratio, were found to meet the imposed requirements in terms of fuel consumption, knock occurrence, exhaust gas temperature and variation of indicated mean effective pressure. By comparing the results of the base point with the results that used exhaust gas recirculation the improvement in fuel consumption of 8.7%, 11.2% and 1.5% at engine speeds of 2000 rpm, 3500 rpm and 5000

  17. Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life.

    Science.gov (United States)

    Sant'Ana, Anderson S; Barbosa, Matheus S; Destro, Maria Teresa; Landgraf, Mariza; Franco, Bernadette D G M

    2012-06-15

    Growth potential (δ) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of δ of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the δ of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7°C) and abuse temperature (15°C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L. monocytogenes was able to grow (δ≥0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L. monocytogenes. The highest δ values were obtained when the RTE vegetables were stored 15°C/6days in collard greens (δ=3.3) and arugula (δ=3.2) (L. monocytogenes) and arugula (δ=4.1) and escarole (δ=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (pvegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L. monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Geoffroy's side-necked turtle [Phrynops geoffroanus (Schweigger, 1812), Testudines: Chelidae] as a model for evolutionary ecotoxicology: relationship between environmental contamination, conditions and genetic variability.

    Science.gov (United States)

    Venancio, L P R; Zuccari, D A P C; Bonini-Domingos, C R

    2013-12-19

    The objective of this study was to evaluate the role of human activity factors, such as environmental contamination and habitat changes, as drivers for changing the physiological, biochemical, and genetic diversity of Geoffroy's side-necked turtle populations in one of the most impacted watersheds in southeastern Brazil. The impact of chemical and organic contamination was determined by ecotoxicological analyses to assess the action of some of the major components involved in protection against oxidative stress, phase I and II detoxification metabolism, and antioxidant capacity. The results indicated the influence of domestic and industrial effluents on detoxification metabolism and oxidative stress. However, in spite of increased activity and effect of EROD (CYP1A1) and glutathione S-transferase (GST) activity, GST average values in the urban area agreed with those expected for hypoxic conditions according to the literature. This observation suggests that increased GST in response to ROS production due to the presence of pollutants increases the antioxidant defense network, controlling the oxidative damage caused by hypoxia and reperfusion. To determine the conditions that are reflected in individual ability (fitness), we evaluated the mathematical relationship between weight and length, and found that changes in body shape and weight increase, allowing inferences about animal health and welfare. The data obtained indicate differences in conditions that are associated with the area, but also with sex and reproductive period, and contamination gradient, indicating a strong influence of environmental stressors on the physiology of the specimens. The evaluation of genetic structure among populations of Preto River and Felicidade Stream, based on microsatellites, demonstrated that there was no genetic differentiation, due to extensive gene flow between the areas and high genetic diversity. However, after analysis of intrapopulation structure, we observed the existence

  19. Model aerodynamic test results for two variable cycle engine coannular exhaust systems at simulated takeoff and cruise conditions. Comprehensive data report. Volume 3: Graphical data book 1

    Science.gov (United States)

    Nelson, D. P.

    1981-01-01

    A graphical presentation of the aerodynamic data acquired during coannular nozzle performance wind tunnel tests is given. The graphical data consist of plots of nozzle gross thrust coefficient, fan nozzle discharge coefficient, and primary nozzle discharge coefficient. Normalized model component static pressure distributions are presented as a function of primary total pressure, fan total pressure, and ambient static pressure for selected operating conditions. In addition, the supersonic cruise configuration data include plots of nozzle efficiency and secondary-to-fan total pressure pumping characteristics. Supersonic and subsonic cruise data are given.

  20. Production dynamics and life cycle of dominant chironomids (diptera, chironomidae) in a subtropical stream in China: adaptation to variable flow conditions in summer and autumn

    Science.gov (United States)

    Yan, Yunjun; Li, Xiaoyu

    2007-07-01

    The production dynamics and trophic basis of 7 dominant species of chironomids were investigated in the area of a second-order river of the Hanjiang River basin, in central China from June 2003 to June 2004. The results showed that Tvetenia discoloripes was by far the most abundant chironomid, dominating the overall standing stock of the taxa. In terms of lif ecycle, Chaetocladius sp., Eukiefferiella potthasti and T. discoloripes developed 1 generation a year, whereas Microtendipes sp. and Pagastia sp. developed two, while Pentaneura sp. and Polypedilum sp. developed three. T. discoloripes was the most productive chironomid with 120.305 8 g/m2. a, Pentaneura sp. and E. potthasti had relatively high production values of >17 g/m2.a, and the rest were 0.5), especially for filter-collectors Microtendipes sp., Chaetocladius sp., Chaetocladius sp., T. discoloripes and Pagastia sp. All species except Pentaneura sp. consumed a large portion of amorphous detritus, constituting more than 90% of their diets, and contributing nearly 90% to their secondary production. All the 7 chironomids represent obvious adaptation to local highly variable climate in summer and autumn in life cycle pattern, production dynamics, and food type.

  1. The influence of variable operating conditions on the design and exploitation of fly ash pneumatic transport systems in thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Stanojevic, M.; Radic, D.; Jovovic, A. (and others) [University of Belgrade, Belgrade (Serbia). Dept. of Processing Engineering

    2008-10-15

    The efficiency of an air-slide pneumatic conveying system depends, first of all, on several basic elements chosen or calculated during the design of a plant: air-slide design parameters, air mover characteristics, as well as the physical and chemical properties of the material to be transported. However, during the exploitation of this type of system which is used for handling ash in thermal-power plants, either gradual and/or sudden changes in the operating conditions can arise. This may be due to changes both in the proportion of ash content and in the flow characteristics of the porous membrane. The consequences of changes in these conditions on the performance of the ash handling system are analyzed, based upon the results of the experimental work carried out on the test rig at the Faculty of Mechanical Engineering in Belgrade, and upon the on-site measurements at the thermal-power plant 'Nikola Tesla B'. 5 refs., 8 figs., 4 tabs.

  2. Influence of PAHs among other coastal environmental variables on total and PAH-degrading bacterial communities.

    Science.gov (United States)

    Sauret, Caroline; Tedetti, Marc; Guigue, Catherine; Dumas, Chloé; Lami, Raphaël; Pujo-Pay, Mireille; Conan, Pascal; Goutx, Madeleine; Ghiglione, Jean-François

    2016-03-01

    We evaluated the relative impact of anthropogenic polycyclic aromatic hydrocarbons (PAHs) among biogeochemical variables on total, metabolically active, and PAH bacterial communities in summer and winter in surface microlayer (SML) and subsurface seawaters (SSW) across short transects along the NW Mediterranean coast from three harbors, one wastewater effluent, and one nearshore observatory reference site. At both seasons, significant correlations were found between dissolved total PAH concentrations and PAH-degrading bacteria that formed a gradient from the shore to nearshore waters. Accumulation of PAH degraders was particularly high in the SML, where PAHs accumulated. Harbors and wastewater outfalls influenced drastically and in a different way the total and active bacterial community structure, but they only impacted the communities from the nearshore zone (PAH concentrations on the spatial and temporal dynamic of total and active communities in this area, but this effect was putted in perspective by the importance of other biogeochemical variables.

  3. Experimental investigation of a low-temperature organic Rankine cycle (ORC) engine under variable heat input operating at both subcritical and supercritical conditions

    International Nuclear Information System (INIS)

    Kosmadakis, George; Manolakos, Dimitris; Papadakis, George

    2016-01-01

    Highlights: • Small-scale ORC engine with converted scroll expander is installed at laboratory. • Design suitable for supercritical operation. • ORC engine tested at temperature equal to 95 °C. • Focus is given on expansion and thermal efficiency. • Supercritical operation showed some promising performance. - Abstract: The detailed experimental investigation of an organic Rankine cycle (ORC) is presented, which is designed to operate at supercritical conditions. The net capacity of this engine is almost 3 kW and the laboratory testing of the engine includes the variation of the heat input and of the hot water temperature. The maximum heat input is 48 kW_t_h, while the hot water temperature ranges from 65 up to 100°C. The tests are conducted at the laboratory and the heat source is a controllable electric heater, which can keep the hot water temperature constant, by switching on/off its electrical resistances. The expansion machine is a modified scroll compressor with major conversions, in order to be able to operate with safety at high pressure (or even supercritical at some conditions). The ORC engine is equipped with a dedicated heat exchanger of helical coil design, suitable for such applications. The speeds of the expander and ORC pump are regulated with frequency inverters, in order to control the cycle top pressure and heat input. The performance of all components is evaluated, while special attention is given on the supercritical heat exchanger and the scroll expander. The performance tests examined here concern the variation of the heat input, while the hot water temperature is equal to 95 °C. The aim is to examine the engine performance at the design conditions, as well as at off-design ones. Especially the latter ones are very important, since this engine will be coupled with solar collectors at the final configuration, where the available heat is varied to a great extent. The engine has been measured at the laboratory, where a thermal

  4. Short-term variability of primary production and inorganic nitrogen uptake related to the environmental conditions in a shallow coastal area (Gulf of Trieste, N Adriatic Sea)

    OpenAIRE

    Cantoni, C; Cozzi, S; Pecchiar, I; Cabrini, M; Mozeti, P; Catalano, G; Umani, Sf

    2003-01-01

    La production primaire et l’assimilation de nitrates et d’ammonium ont été mesurées en même temps que les facteurs du milieu entre octobre 1999 et février 2001 dans le golfe de Trieste. La variabilité est élevée en raison de l’action combinée des conditions météorologiques, de la circulation et des apports des rivières. La production primaire varie entre 0,2 et 15,9 μmol C dm–3 j–1 alors que l’assimilation de nitrates va de 0,8 à 442 nmol N dm–3 j–1, montrant une tendance identique au carbone...

  5. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    . Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...

  6. Variabilidade de parâmetros eletromiográficos e cinemáticos em diferentes condições de marcha em idosos Electromyographic and kinematic parameters variability in different conditions of motion in the elderly

    Directory of Open Access Journals (Sweden)

    Camilla Zamfolini Hallal

    2013-03-01

    Full Text Available O objetivo deste estudo foi investigar a influência do medo de cair e da dupla tarefa sobre a variabilidade de parâmetros eletromiográficos e cinemáticos da marcha de idosas. Dezessete universitárias (21,47 ± 2,06 anos e dezoito idosas (65,33 ± 3,14 anos, fisicamente ativas, realizaram teste de marcha em três condições: velocidade de preferência; medo de cair; e dupla tarefa. A atividade eletromiográfica dos músculos do membro inferior dominante e o comprimento e tempo de passada foram registrados. Utilizou-se o teste ANOVA Two-Way (pThe main goal of this study was to investigate the influence of fear of fall and dual task on electromyographic and kinematic variability parameters on the gait of older females. Seventeen college students (21,47 ± 2,06 years old and eighteen older female adults, both groups were physically fit and performed the gait test on three different conditions: walking at self-select speed, fear of fall and dual task. Electromyographic activity was measured on muscles of dominant leg and stride time was recorded. ANOVA two-way (p<0.05 was used. Electromyographic and kinematic gait variability were higher in older adult groups. However, for the comparison between gait conditions was only found significant difference for electromyographic variability. In line with this, the higher EMG and kinematic variability in older adults suggest that aging contributes for a higher motor challenge while walking, which may be predispose these individuals a higher risk of fall.

  7. The scale effect on soil erosion. A plot approach to understand connectivity on slopes under cultivation at variable plot sizes and under Mediterranean climatic conditions

    Science.gov (United States)

    Cerdà, Artemi; Bagarello, Vicenzo; Ferro, Vito; Iovino, Massimo; Borja, Manuel Estaban Lucas; Francisco Martínez Murillo, Juan; González Camarena, Rafael

    2017-04-01

    Sediment Yield at Catchment Scale using Connectivity Components. Land Degradation and Development 27 (4): 933-945. doi:10.1002/ldr.2512. Parsons, A.J., Abrahams, A.D., Luk, S.H. 1990. Hydraulics of interrill overland flow on a semi-arid hillslope, southern Arizona. Journal of Hydrology, 117(1), 255-273. Parsons, A.J., Abrahams, A. D., Wainwright, J. 1996. Responses of interrill runoff and erosion rates to vegetation change in southern Arizona. Geomorphology, 14(4), 311-317. Parsons A.J., Bracken L., Peoppl , R., Wainwright J., Keesstra, S.D., 2015. Editorial: Introduction to special issue on connectivity in water and sediment dynamics. In press in Earth Surface Processes and Landforms. DOI: 10.1002/esp.3714 Poeppl, R.,E. Maroulis, J., Keesstra, S.D., 2016. Geomorphology. A conceptual connectivity framework for understanding geomorphic change in human-impacted fluvial systems. http://dx.doi.org/10.1016/j.geomorph.2016.07.033 Sadeghi, S.H.R., Gholami, L., Sharifi, E., Khaledi Darvishan, A., Homaee, M. Scale effect on runoff and soil loss control using rice straw mulch under laboratory conditions. (2015) Solid Earth, 6 (1), pp. 1-8.. DOI: http://dx.doi.org/10.5194/se-6-1-2015 Wainwright, J., Parsons, A.J., Schlesinger, W.H., Abrahams, A.D. 2002. Hydrology-vegetation interactions in areas of discontinuous flow on a semi-arid bajada, southern New Mexico. Journal of Arid Environments, 51(3), 319-338.

  8. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  9. Study of the impact on PSA success criteria of the variability of the initial liquid level in case of the loss of the RHR system accident scenario under mid-loop operating conditions

    International Nuclear Information System (INIS)

    Villanueva, J.F.; Carlos, S.; Martorell, S.; Serradell, V.; Pelayo, F.; Mendizabal, R.; Cirauqui, C.; Sol, I.

    2005-01-01

    Probabilistic safety assessment (PSA) is recognized nowadays as an important tool to support risk-informed decision-making aimed at providing both operational flexibility and plant safety [1]. Experience of current PSA studies shows the importance of some risky scenarios with the plant at low power and shutdown conditions as compared to the accident scenarios with the plant operating at full power. In particular, current low power and shutdown PSA (LPSA) studies shows that the loss of the Residual Heat Removal System (RHRS) transient is one of the most risk-significant events under low power conditions [2]. This accident type is supposed to occur for various plant operating states, of which mid-loop operation represents one of the main contributors [3]. LPSA has widely used methods for thermal-hydraulic analysis that play an important role in determining success criteria of safety-related functions involved to mitigate the severity of accident scenarios with the plant operating in such conditions. Various best estimate thermal-hydraulic analysis codes have been used to analyze the loss of the RHRS during low power and shutdown conditions [4, 5]. It is known that RELAP code can give good results as derived after a number of benchmark exercises using results from experiments at research facilities (e.g. ROSA-IV, BETHSY, PKL). [6] Previous research has shown how thermal-hydraulic phenomena after the loss of the RHRS, e.g. peak reactor coolant system pressure, are sensitive to the initial liquid level at the time of loss of the RHRS [2]. This paper presents the results of the study of the thermalhydraulic analysis of the accident scenarios after the loss of the RHRS under mid-loop conditions paying particular attention to the analysis of the effect of the variability of the initial liquid level on the success criteria of the safety-related functions considered in a typical LPSA [3]. (author)

  10. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  11. Pantanal of Cáceres: granulometric composition of bottom sediments in the Paraguay River between the outfall of the Cabaçal River and the city of Cáceres, Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Roberto dos Santos Leandro

    2012-08-01

    Full Text Available The objective of the study was to verify the granulometric composition of bottom sediments along the longitudinal profile of the Paraguay River between the outfall of the Cabaçal River and the city of Cáceres, Mato Grosso, comprised by the geographic coordinates 15°58’00’’ and 16°50’00’’ South Latitude and 57°40’00’’ and 57°44’00’’ West Longitude. Work activity was conducted to characterize the sites and sediments collection with Van Veen sediment sampler (seven samples; textural analysis of the sediments by the pipetting and sieving method (the method uses a combination of sieving and sedimentation. The Paraguay River exhibits a meandering style with two distinct periods (periodic flooding regime and drought that associated with of bottom sediments alternate processes of erosion, transport and deposition from the discernible changes in the complex landscaping. Thus, the concentration of sand in the bed load transported in the channel (five samples is related to environmental elements and land use. The fine sediments are transferred to the features (bays and ponds and flood plain; the intense fluvial dynamics and the course (alluvial deposition areas contribute to changes in channel and morphologic features (capacity transport and sediment depositions.

  12. Leaf area index estimation in a pine plantation with LAI-2000 under direct sunlight conditions: relationship with inventory and hydrologic variables; Estimacion del indice de area foliar en pinares de repolacion con LAI-2000 bajo radiacion solar directa: relacion con variables de inventario e hidrologicas

    Energy Technology Data Exchange (ETDEWEB)

    Molina, A.; Campo, A. D. del

    2011-07-01

    LAI is a key factor in light and rainfall interception processes in forest stands and, for this reason, is called to play an important role in global change adaptive silviculture. Therefore, it is necessary to develop practical and operative methodologies to measure this parameter as well as simple relationships with other silviculture variables. This work has studied 1) the feasibility of LAI-2000 sensor in estimating LAI-stand when readings are taken under direct sunlight conditions; and 2) the ability of LAI in studying rainfall partitioned into throughfall (T) in an Aleppo pine stand after different thinning intensities, as well as its relationships to basal area, (G), cover (FCC), and tree density (D). Results showed that the angular correction scheme applied to LAI-2000 direct-sunlight readings stabilized them for different solar angles, allowing a better operational use of LAI-2000 in Mediterranean areas, where uniform overcast conditions are difficult to meet and predict. Forest cover showed the highest predictive ability of LAI (R{sup 2} = 0.98; S = 0.28), then G (R{sup 2} = 0.96; S = 0.43) and D (R{sup 2} = 0.50; S = 0.28). In the hydrological plane, T increased with thinning intensity, being G the most explanatory variable (R{sup 2} = 0.81; S = 3.07) and LAI the one that showed the poorest relation with it (R{sup 2} = 0.69; S = 3.95). These results open a way for forest hydrologic modeling taking LAI as an input variable either estimated form LAI-2000 or deducted from inventory data. (Author) 36 refs.

  13. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.

    2007-01-01

    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...... of a discrete random variable....

  14. Contribution to the electrothermal simulation in power electronics. Development of a simulation methodology applied to switching circuits under variable operating conditions; Contribution a la simulation electrothermique en electronique de puissance. Developpement d`une methode de simulation pour circuits de commutation soumis a des commandes variables

    Energy Technology Data Exchange (ETDEWEB)

    Vales, P.

    1997-03-19

    In modern hybrid or monolithic integrated power circuits, electrothermal effects can no longer be ignored. A methodology is proposed in order to simulate electrothermal effects in power circuits, with a significant reduction of the computation time while taking into account electrical and thermal time constants which are usually widely different. A supervising program, written in Fortran, uses system call sequences and manages an interactive dialog between a fast thermal simulator and a general electrical simulator. This explicit coupling process between two specific simulators requires a multi-task operating system. The developed software allows for the prediction of the electrothermal power dissipation drift in the active areas of components, and the prediction of thermally-induced coupling effects between adjacent components. An application to the study of hard switching circuits working under variable operating conditions is presented

  15. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  16. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  17. Investigations of Spatial and Temporal Variability of Ocean and Ice Conditions in and Near the Marginal Ice Zone. The “Marginal Ice Zone Observations and Processes Experiment” (MIZOPEX) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    DeMott, P. J. [Colorado State Univ., Fort Collins, CO (United States); Hill, T. C.J. [Colorado State Univ., Fort Collins, CO (United States)

    2016-02-01

    Despite the significance of the marginal ice zones of the Arctic Ocean, basic parameters such as sea surface temperature (SST) and a range of sea-ice characteristics are still insufficiently understood in these areas, and especially so during the summer melt period. The field campaigns summarized here, identified collectively as the “Marginal Ice Zone Ocean and Ice Observations and Processes Experiment” (MIZOPEX), were funded by U.S. National Aeronautic and Space Administration (NASA) with the intent of helping to address these information gaps through a targeted, intensive observation field campaign that tested and exploited unique capabilities of multiple classes of unmanned aerial systems (UASs). MIZOPEX was conceived and carried out in response to NASA’s request for research efforts that would address a key area of science while also helping to advance the application of UASs in a manner useful to NASA for assessing the relative merits of different UASs. To further exercise the potential of unmanned systems and to expand the science value of the effort, the field campaign added further challenges such as air deployment of miniaturized buoys and coordinating missions involving multiple aircraft. Specific research areas that MIZOPEX data were designed to address include relationships between ocean skin temperatures and subsurface temperatures and how these evolve over time in an Arctic environment during summer; variability in sea-ice conditions such as thickness, age, and albedo within the marginal ice zone (MIZ); interactions of SST, salinity, and ice conditions during the melt cycle; and validation of satellite-derived SST and ice concentration fields provided by satellite imagery and models.

  18. Variabilidade espacial de MO, P, K e CTC do solo sob diferentes usos e manejos Spatial variability of MO, P, K and CTC of soil under different use and management conditions

    Directory of Open Access Journals (Sweden)

    Eloiza Gomes Silva Cavalcante

    2007-04-01

    Full Text Available O estudo da variabilidade espacial dos atributos químicos dos solos é particularmente importante em áreas onde o solo está submetido a diferentes manejos. O trabalho foi desenvolvido em Selvíria (MS, com o objetivo de avaliar a variabilidade espacial da matéria orgânica (MO, o fósforo (P, do potássio (K e a capacidade de troca catiônica (CTC em um Latossolo Vermelho distrófico sob diferentes usos e manejos. Os solos foram amostrados em uma malha, com intervalos regulares de 2m, perfazendo um total de 64 pontos, nas profundidades de 0,0-0,1m e 0,1-0,2m, nas seguintes áreas: vegetação natural (cerrado, plantio direto, plantio convencional e pastagem. O sistema de plantio direto apresentou acúmulo significativo de matéria orgânica, fósforo, potássio e elevação da CTC em relação aos demais sistemas estudados, além da melhoria nas condições químicas do solo. A matéria orgânica foi maior em relação ao sistema natural. As maiores variabilidades medidas por meio do coeficiente de variação foram observadas para o fósforo e o potássio, sendo que a matéria orgânica e a CTC apresentaram coeficiente de variação médio nos diferentes usos e manejos do solo.The study of the spatial variability of the chemical attributes of the soils is particularly important in areas where the soil is submitted to different management. This work was developed in Selvíria (MS with the objective of evaluating the spatial variability of the organic matter (MO, phosphorus (P, potassium (K and cation exchange capacity (CEC in a oxisol under different use and management conditions. The soils were collected in a grid, with regular intervals of 2m, total of 64 points, in the depths of 0,0-0,1m and 0,1-0,2m, in the use and management were: native vegetation (savannah, no-tillage, conventional system and pasture. The system of no-tillage presented significant accumulation of organic matter, phosphorus, potassium and elevation of CEC in relation to

  19. Quantifying the effect of nighttime interactions between roots and canopy physiology and their control of water and carbon cycling on feedbacks between soil moisture and terrestrial climatology under variable environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Domec, Jean-Christophe [North Carolina State Univ., Raleigh, NC (United States); Palmroth, Sari [Duke Univ., Durham, NC (United States); Oren, Ram [Duke Univ., Durham, NC (United States); Swenson, Jennifer [Duke Univ., Durham, NC (United States); King, John S. [North Carolina State Univ., Raleigh, NC (United States); Noormets, Asko [North Carolina State Univ., Raleigh, NC (United States)

    2016-04-01

    The primary objective of this project is to characterize and quantify how the temporal variability of hydraulic redistribution (HR) and its physiological regulation in unmanaged and complex forests is affecting current water and carbon exchange and predict how future climate scenarios will affect these relationships and potentially feed back to the climate. Specifically, a detailed study of ecosystem water uptake and carbon exchange in relation to root functioning was proposed in order to quantify the mechanisms controlling temporal variability of soil moisture dynamic and HR in three active AmeriFlux sites, and to use published data of two other inactive AmeriFlux sites. Furthermore, data collected by our research group at the Duke Free Air CO2 enrichment (FACE) site was also being utilized to further improve our ability to forecast future environmental impacts of elevated CO2 concentration on soil moisture dynamic and its effect on carbon sequestration and terrestrial climatology. The overarching objective being to forecast, using a soil:plant:atmosphere model coupled with a biosphere:atmosphere model, the impact of root functioning on land surface climatology. By comparing unmanaged sites to plantations, we also proposed to determine the effect of land use change on terrestrial carbon sequestration and climatology through its effect on soil moisture dynamic and HR. Our simulations of HR by roots indicated that in some systems HR is an important mechanism that buffers soil water deficit, affects energy and carbon cycling; thus having significant implications for seasonal climate. HR maintained roots alive and below 70% loss of conductivity and our simulations also showed that the increased vapor pressure deficit at night under future conditions was sufficient to drive significant nighttime transpiration at all sites, which reduced HR. This predicted reduction in HR under future climate conditions played an important regulatory role in land atmosphere interactions

  20. Confounding of three binary-variables counterfactual model

    OpenAIRE

    Liu, Jingwei; Hu, Shuang

    2011-01-01

    Confounding of three binary-variables counterfactual model is discussed in this paper. According to the effect between the control variable and the covariate variable, we investigate three counterfactual models: the control variable is independent of the covariate variable, the control variable has the effect on the covariate variable and the covariate variable affects the control variable. Using the ancillary information based on conditional independence hypotheses, the sufficient conditions...

  1. Surfing wave climate variability

    Science.gov (United States)

    Espejo, Antonio; Losada, Iñigo J.; Méndez, Fernando J.

    2014-10-01

    International surfing destinations are highly dependent on specific combinations of wind-wave formation, thermal conditions and local bathymetry. Surf quality depends on a vast number of geophysical variables, and analyses of surf quality require the consideration of the seasonal, interannual and long-term variability of surf conditions on a global scale. A multivariable standardized index based on expert judgment is proposed for this purpose. This index makes it possible to analyze surf conditions objectively over a global domain. A summary of global surf resources based on a new index integrating existing wave, wind, tides and sea surface temperature databases is presented. According to general atmospheric circulation and swell propagation patterns, results show that west-facing low to middle-latitude coasts are more suitable for surfing, especially those in the Southern Hemisphere. Month-to-month analysis reveals strong seasonal variations in the occurrence of surfable events, enhancing the frequency of such events in the North Atlantic and the North Pacific. Interannual variability was investigated by comparing occurrence values with global and regional modes of low-frequency climate variability such as El Niño and the North Atlantic Oscillation, revealing their strong influence at both the global and the regional scale. Results of the long-term trends demonstrate an increase in the probability of surfable events on west-facing coasts around the world in recent years. The resulting maps provide useful information for surfers, the surf tourism industry and surf-related coastal planners and stakeholders.

  2. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  3. An evaluation of FIA's stand age variable

    Science.gov (United States)

    John D. Shaw

    2015-01-01

    The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume,...

  4. The practical outfall of DOE compliance agreements

    International Nuclear Information System (INIS)

    Smith, Leanne; Henrie, Gregory O.

    1992-01-01

    Perhaps the significant regulatory issue facing the Department of Energy (DOE or the Department) is the compliant treatment, storage, and disposal of mixed (radioactive and hazardous) waste. Since DOE'S By-Product Rulemaking in 1987, when the Department acknowledged that the Resource Conservation and Recovery Act (RCRA) applied to the hazardous component of mixed waste, DOE has repeatedly communicated to the Environmental Protection Agency (EPA) and host States that, for mixed waste, DOE is not always able to strictly comply with RCRA standards and that bringing treatment on-line in an expeditious manner is proving very difficult. One of the most effective methods used between DOE and its regulators to address mixed waste management issues is the negotiation of compliance agreements. These agreements establish formal mile stones for bringing DOE sites into compliance. The milestones are not completed without overcoming technical roadblocks and a struggle for funding. However, agreements can establish technically attainable compliance methods that take into account the special problems radiation introduces into RCRA waste management. Compliance agreements help promote a cooperative relationship within the Department and between DOE and its regulators in that all parties have reached agreement and have a stake in attaining the same goal. Where agreements exist, mixed waste compliance efforts can proceed in a situation where all parties have a full understanding of each other's needs and expectations. (author)

  5. Variable collimator

    International Nuclear Information System (INIS)

    Richey, J.B.; McBride, T.R.; Covic, J.

    1979-01-01

    This invention describes an automatic variable collimator which controls the width and thickness of X-ray beams in X-ray diagnostic medical equipment, and which is particularly adapted for use with computerized axial tomographic scanners. A two-part collimator is provided which shapes an X-ray beam both prior to its entering an object subject to radiographic analysis and after the attenuated beam has passed through the object. Interposed between a source of radiation and the object subject to radiographic analysis is a first or source collimator. The source collimator causes the X-ray beam emitted by the source of radiation to be split into a plurality of generally rectangular shaped beams. Disposed within the source collimator is a movable aperture plate which may be used to selectively vary the thickness of the plurality of generally rectangular shaped beams transmitted through the source collimator. A second or receiver collimator is interposed between the object subject to radiographic analysis and a series of radiation detectors. The receiver collimator is disposed to receive the attenuated X-ray beams passing through the object subject to radiographic analysis. Located within the receiver collimator are a plurality of movable aperture plates adapted to be displaced relative to a plurality of fixed aperture plates for the purpose of varying the width and thickness of the attenuated X-ray beams transmitted through the object subject to radiographic analysis. The movable aperture plates of the source and receiver collimators are automatically controlled by circuitry which is provided to allow remote operation of the movable aperture plates

  6. Variable cycle engine

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.P.; Sprunger, E.V.

    1980-09-16

    A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relatively small high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

  7. Seasonal variability of the parameters of the Ball-Berry model of stomatal conductance in maize (Zea mays L.) and sunflower (Helianthus annuus L.) under well-watered and water-stressed conditions.

    Science.gov (United States)

    Miner, Grace L; Bauerle, William L

    2017-09-01

    The Ball-Berry (BB) model of stomatal conductance (g s ) is frequently coupled with a model of assimilation to estimate water and carbon exchanges in plant canopies. The empirical slope (m) and 'residual' g s (g 0 ) parameters of the BB model influence transpiration estimates, but the time-intensive nature of measurement limits species-specific data on seasonal and stress responses. We measured m and g 0 seasonally and under different water availability for maize and sunflower. The statistical method used to estimate parameters impacted values nominally when inter-plant variability was low, but had substantial impact with larger inter-plant variability. Values for maize (m = 4.53 ± 0.65; g 0  = 0.017 ± 0.016 mol m -2 s -1 ) were 40% higher than other published values. In maize, we found no seasonal changes in m or g 0 , supporting the use of constant seasonal values, but water stress reduced both parameters. In sunflower, inter-plant variability of m and g 0 was large (m = 8.84 ± 3.77; g 0  = 0.354 ± 0.226 mol m -2 s -1 ), presenting a challenge to clear interpretation of seasonal and water stress responses - m values were stable seasonally, even as g 0 values trended downward, and m values trended downward with water stress while g 0 values declined substantially. © 2017 John Wiley & Sons Ltd.

  8. Bioequivalence of two lansoprazole delayed release capsules 30 mg in healthy male volunteers under fasting, fed and fasting-applesauce conditions: a partial replicate crossover study design to estimate the pharmacokinetics of highly variable drugs.

    Science.gov (United States)

    Thota, S; Khan, S M; Tippabhotla, S K; Battula, R; Gadiko, C; Vobalaboina, V

    2013-11-01

    An open-label, 2-treatment, 3-sequence, 3-period, single-dose, partial replicate crossover studies under fasting (n=48), fed (n=60) and fasting-applesauce (n=48) (sprinkled on one table spoonful of applesauce) modalities were conducted in healthy adult male volunteers to evaluate bioequivalence between 2 formulations of lansoprazole delayed release capsules 30 mg. In all the 3 studies, as per randomization, either test or reference formulations were administered in a crossover manner with a required washout period of at least 7 days. Blood samples were collected adequately (0-24 h) to determine lansoprazole plasma concentrations using a validated LC-MS/MS analytical method. To characterize the pharmacokinetic parameters (Cmax, AUC0-t, AUC0-∞, Tmax, Kel and T1/2) of lansoprazole, non-compartmental analysis and ANOVA was applied on ln-transformed values. The bioequivalence was tested based on within-subject variability of the reference formulation. In fasting and fed studies (within-subject variability>30%) bioequivalence was evaluated with scaled average bioequivalence, hence for the pharmacokinetic parameters Cmax, AUC0-t and AUC0-∞, the 95% upper confidence bound for (μT-μR)2-θσ2 WR was ≤0, and the point estimates (test-to-reference ratio) were within the regulatory acceptance limit 80.00-125.00%. In fasting-applesauce study (within-subject variability<30%) bioequivalence was evaluated with average bioequivalence, the 90% CI of ln-transformed data of Cmax, AUC0-t and AUC0-∞ were within the regulatory acceptance limit 80.00-125.00%. Based on these aforesaid statistical inferences, it was concluded that the test formulation is bioequivalent to reference formulation. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Investigation of load reduction for a variable speed, variable pitch, and variable coning wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, K. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A two bladed, variable speed and variable pitch wind turbine was modeled using ADAMS{reg_sign} to evaluate load reduction abilities of a variable coning configuration as compared to a teetered rotor, and also to evaluate control methods. The basic dynamic behavior of the variable coning turbine was investigated and compared to the teetered rotor under constant wind conditions as well as turbulent wind conditions. Results indicate the variable coning rotor has larger flap oscillation amplitudes and much lower root flap bending moments than the teetered rotor. Three methods of control were evaluated for turbulent wind simulations. These were a standard IPD control method, a generalized predictive control method, and a bias estimate control method. Each control method was evaluated for both the variable coning configuration and the teetered configuration. The ability of the different control methods to maintain the rotor speed near the desired set point is evaluated from the RMS error of rotor speed. The activity of the control system is evaluated from cycles per second of the blade pitch angle. All three of the methods were found to produce similar results for the variable coning rotor and the teetered rotor, as well as similar results to each other.

  10. Uranium tetrafluoride reduction closed bomb. Part I: Reduction process general conditions; Reduccion del tetrafluoruro de uranio en bomba cerrada. Part I. estudio de las variables generales del proceso de reduccion

    Energy Technology Data Exchange (ETDEWEB)

    Anca Abati, R; Lopez Rodriguez, M

    1961-07-01

    General conditions about the metallo thermic reduction in small bombs (250 and 800 gr. of uranium) has been investigated. Factors such as kind and granulometry of the magnesium used, magnesium excess and preheating temperature, which affect yields and metal quality have been considered. magnesium excess increased yields in a 15% in the small bomb, about the preheating temperature, there is a range between which yields and metal quality does not change. All tests have been made with graphite linings. (Author) 18 refs.

  11. The method of the gas-dynamic centrifugal compressor stage characteristics recalculation for variable rotor rotational speeds and the rotation angle of inlet guide vanes blades if the kinematic and dynamic similitude conditions are not met

    Science.gov (United States)

    Vanyashov, A. D.; Karabanova, V. V.

    2017-08-01

    A mathematical description of the method for obtaining gas-dynamic characteristics of a centrifugal compressor stage is proposed, taking into account the control action by varying the rotor speed and the angle of rotation of the guide vanes relative to the "basic" characteristic, if the kinematic and dynamic similitude conditions are not met. The formulas of the correction terms for the non-dimensional coefficients of specific work, consumption and efficiency are obtained. A comparative analysis of the calculated gas-dynamic characteristics of a high-pressure centrifugal stage with experimental data is performed.

  12. Sufficiency of Bell's conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gutkowski, D; Masotto, G [Istituto di Matematica della Universita di Palermo (Italy); Valdes, M V

    1979-04-11

    It is shown that, if the results of measurements of spin components of two-spin one-half particles coupled to a singlet state with respect to n=3 directions satisfy Bell's conditions, then these results are compatible with a local hidden-variable theory. The previous statement is extended to the case n=4.

  13. Chromosomal Conditions

    Science.gov (United States)

    ... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Chromosomal conditions Chromosomal conditions ... Disorders See also: Genetic counseling , Your family health history Last reviewed: February, 2013 ... labor & premature birth The newborn intensive care unit (NICU) Birth defects & ...

  14. Classification and prediction of port variables

    Energy Technology Data Exchange (ETDEWEB)

    Molina Serrano, B.

    2016-07-01

    Many variables are included in planning and management of port terminals. They can beeconomic, social, environmental and institutional. Agent needs to know relationshipbetween these variables to modify planning conditions. Use of Bayesian Networks allowsfor classifying, predicting and diagnosing these variables. Bayesian Networks allow forestimating subsequent probability of unknown variables, basing on know variables.In planning level, it means that it is not necessary to know all variables because theirrelationships are known. Agent can know interesting information about how port variablesare connected. It can be interpreted as cause-effect relationship. Bayesian Networks can beused to make optimal decisions by introduction of possible actions and utility of theirresults.In proposed methodology, a data base has been generated with more than 40 port variables.They have been classified in economic, social, environmental and institutional variables, inthe same way that smart port studies in Spanish Port System make. From this data base, anetwork has been generated using a non-cyclic conducted grafo which allows for knowingport variable relationships - parents-children relationships-. Obtained network exhibits thateconomic variables are – in cause-effect terms- cause of rest of variable typologies.Economic variables represent parent role in the most of cases. Moreover, whenenvironmental variables are known, obtained network allows for estimating subsequentprobability of social variables.It has been concluded that Bayesian Networks allow for modeling uncertainty in aprobabilistic way, even when number of variables is high as occurs in planning andmanagement of port terminals. (Author)

  15. Interplanetary variability recorded by the sled instrument aboard the Phobos spacecraft during that period of solar cycle 22 characterized by a transition from solar minimum- to solar maximum-dominated conditions

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S.M.P. (Saint Patrick' s Coll., Maynooth (Ireland)); Afonin, V.V.; Gringauz, K.I. (AN SSSR, Moscow (USSR). Space Research Inst.) (and others)

    Twin telescope particle detector systems SLED-1 and SLED-2, with the capability of monitoring electron and ion fluxes within an energy range spanning approximately 30 keV to a few megaelectron volts, were individually launched on the two spacecraft (Phobos-2 and Phobos-1, respectively) of the Soviet Phobos Mission to Mars and its moons in July 1988. A short description of the SLED instrument and a preliminary account of representative solar-related particle enhancements recorded by SLED-1 and SLED-2 during the Cruise Phase, and by SLED-1 in the near Martian environment (within the interval 25 July 1988-26 March 1989) are presented. These observations were made while the interplanetary medium was in the course of changing over from solar minimum- to solar maximum-dominated conditions and examples are presented of events associated with each of these phenomenological states. (author).

  16. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  17. Partitioning soil CO2 fluxes by tree-girdling in a Mediterranean (Pinus pinaster) ecosystem reveals a different response of autotrophic and heterotrophic components to environmental variables and photosynthesis under drought conditions

    Science.gov (United States)

    Matteucci, M.; Cescatti, A.; Gruening, C.; Ballarin, I. G.; Guenther, S.; Magnani, F.; Nali, C.; Lorenzini, G.

    2012-04-01

    The response of ecosystems to environmental factors, such as temperature and rainfall, is crucial to understand the impact of climate change on the terrestrial C cycle. Forest soil respiration represents the main pathway by which photosynthetically assimilated C is released to atmosphere; its intensity depends not only on soil environmental conditions, but also on the availability of organic substrates respired by roots and microorganisms. Several techniques have been applied to partition the autotrophic and heterotrophic components of soil respiration in boreal and temperate forests; there is a general lack of information, on the contrary, on the dynamics of soil CO2 efflux in Mediterranean ecosystems. The IPCC A1B scenario highlighted the importance of the Mediterranean area since it is expected to experience a temperature increase (from 2.2 °C to 5.1 °C) and a rainfall reduction ranging from -4 to -27% on annual basis. We used the tree-girdling technique together with periodic chamber-based measurements to study the partitioning of total soil respiration (Rs) into its autotrophic (Ra) and heterotrophic (Rh) components in a 60-year old forest in Central Italy (San Rossore) dominated by Pinus pinaster. This technique has been extensively used to block the flux of photosynthates from leaves to roots, thus stopping the autotrophic root respiration in the soil. We found that two weeks after the treatment soil respiration in the girdled plots decreased by 29% and remained stable over the period of analysis, suggesting that Rh dominates total soil respiration. The anomalous low rainfall regimen of May to October 2011 (102 mm cumulated rain) associated with average air temperatures (with a mean value of 19,6 °C over the period) gave us the opportunity to investigate the decoupled response of soil respiration to water and temperature. Time series analysis performed under this severe drought conditions showed overall low values of soil respiration with three clear

  18. Learning conditional Gaussian networks

    DEFF Research Database (Denmark)

    Bøttcher, Susanne Gammelgaard

    This paper considers conditional Gaussian networks. The parameters in the network are learned by using conjugate Bayesian analysis. As conjugate local priors, we apply the Dirichlet distribution for discrete variables and the Gaussian-inverse gamma distribution for continuous variables, given...... a configuration of the discrete parents. We assume parameter independence and complete data. Further, to learn the structure of the network, the network score is deduced. We then develop a local master prior procedure, for deriving parameter priors in these networks. This procedure satisfies parameter...... independence, parameter modularity and likelihood equivalence. Bayes factors to be used in model search are introduced. Finally the methods derived are illustrated by a simple example....

  19. Miscellaneous conditions

    International Nuclear Information System (INIS)

    Berquist, T.H.; Hoffman, A.D.

    1989-01-01

    This paper reports on numerous conditions (systemic diseases, metabolic diseases, etc.) that may also affect the foot and ankle. In many cases, imaging of the foot and ankle is not performed for primary diagnostic purposes. However, radiographic changes do occur with these conditions. Therefore, it is important to be aware of radiographic abnormalities that these diseases may cause in the foot and ankle

  20. Measuring variability in trophic status in the Lake Waco/Bosque River Watershed

    Directory of Open Access Journals (Sweden)

    Rodriguez Angela D

    2008-01-01

    Full Text Available Abstract Background Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal in situ variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment. Methods We used the passive diffusion periphytometer to measure in-situ nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll a production in the periphytometers was used as an indicator of baseline chlorophyll a productivity and of maximum primary productivity (MPP in response to nutrient enrichment (nitrogen and phosphorus. We evaluated the lotic ecosystem trophic status index (LETSI using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site. Results The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02 located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05 were the next most enriched sites. Trophic class varied for enriched sites over seasons. Conclusion Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring in situ responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show

  1. Learning dynamic Bayesian networks with mixed variables

    DEFF Research Database (Denmark)

    Bøttcher, Susanne Gammelgaard

    This paper considers dynamic Bayesian networks for discrete and continuous variables. We only treat the case, where the distribution of the variables is conditional Gaussian. We show how to learn the parameters and structure of a dynamic Bayesian network and also how the Markov order can be learned...

  2. Quantification of variability in bedform geometry

    NARCIS (Netherlands)

    van der Mark, C.F.; Blom, Astrid; Hulscher, Suzanne J.M.H.

    2008-01-01

    We analyze the variability in bedform geometry in laboratory and field studies. Even under controlled steady flow conditions in laboratory flumes, bedforms are irregular in size, shape, and spacing, also in case of well-sorted sediment. Our purpose is to quantify the variability in bedform geometry.

  3. Hidden variables and locality in quantum theory

    International Nuclear Information System (INIS)

    Shiva, Vandana.

    1978-12-01

    The status of hidden variables in quantum theory has been debated since the 1920s. The author examines the no-hidden-variable theories of von Neumann, Kochen, Specker and Bell, and finds that they all share one basic assumption: averaging over the hidden variables should reproduce the quantum mechanical probabilities. Von Neumann also makes a linearity assumption, Kochen and Specker require the preservation of certain functional relations between magnitudes, and Bell proposes a locality condition. It has been assumed that the extrastatistical requirements are needed to serve as criteria of success for the introduction of hidden variables because the statistical condition is trivially satisfied, and that Bell's result is based on a locality condition that is physically motivated. The author shows that the requirement of weak locality, which is not physically motivated, is enough to give Bell's result. The proof of Bell's inequality works equally well for any pair of commuting magnitudes satisfying a condition called the degeneracy principle. None of the no-hidden-variable proofs apply to a class of hidden variable theories that are not phase-space reconstructions of quantum mechanics. The author discusses one of these theories, the Bohm-Bub theory, and finds that hidden variable theories that re all the quantum statistics, for single and sequential measurements, must introduce a randomization process for the hidden variables after each measurement. The philosophical significance of this theory lies in the role it can play in solving the conceptual puzzles posed by quantum theory

  4. Ecosystem variability in west Greenland waters

    DEFF Research Database (Denmark)

    Buch, E.; Pedersen, Søren Anker; Ribergaard, M. H.

    2004-01-01

    A review of the climate conditions off West Greenland during the past 50 years shows large variability in the atmospheric, oceanographic and sea-ice variables, as well as in fish stocks. A positive relationship is found between water temperature and the recruitment of cod and redfish, whereas the...

  5. Contextuality is about identity of random variables

    International Nuclear Information System (INIS)

    Dzhafarov, Ehtibar N; Kujala, Janne V

    2014-01-01

    Contextual situations are those in which seemingly ‘the same’ random variable changes its identity depending on the conditions under which it is recorded. Such a change of identity is observed whenever the assumption that the variable is one and the same under different conditions leads to contradictions when one considers its joint distribution with other random variables (this is the essence of all Bell-type theorems). In our Contextuality-by-Default approach, instead of asking why or how the conditions force ‘one and the same’ random variable to change ‘its’ identity, any two random variables recorded under different conditions are considered different ‘automatically.’ They are never the same, nor are they jointly distributed, but one can always impose on them a joint distribution (probabilistic coupling). The special situations when there is a coupling in which these random variables are equal with probability 1 are considered noncontextual. Contextuality means that such couplings do not exist. We argue that the determination of the identity of random variables by conditions under which they are recorded is not a causal relationship and cannot violate laws of physics. (paper)

  6. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  7. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  8. Hysteresis compensation of smart actuators under variable stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, A. [DII, Seconda Universita degli Studi di Napoli, via Roma 29, 81031 Aversa (Italy); Davino, D. [DING, Universita degli Studi del Sannio, piazza Roma, 82100 Benevento (Italy); De Maria, G.; Natale, C.; Pirozzi, S. [DII, Seconda Universita degli Studi di Napoli, via Roma 29, 81031 Aversa (Italy); Visone, C. [DING, Universita degli Studi del Sannio, piazza Roma, 82100 Benevento (Italy)], E-mail: visone@unisannio.it

    2008-02-01

    A new model able to describe magnetostriction for slowly varying mechanical load is presented. The model and its pseudo-compensator exploit the formalism of the classical Preisach model and is therefore easy to implement and well behaved. Experimental results showing the encouraging performances of the approach are provided.

  9. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  10. Aquatic conditions

    Science.gov (United States)

    Warren E. Heilman

    1999-01-01

    This publication provides citizens, private and public organizations, scientists, and others with information about the aquatic conditions in or near national forests in the Ozark-Ouachita Highlands: the Mark Twain in Missouri, the Ouachita in Arkansas and Oklahoma, and the Ozark-St. Francis National Forests in Arkansas. This report includes water quality analyses...

  11. Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Duncan, Joanne P.

    2003-02-28

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  12. Evolution of the sensor fish device for measuring physical conditions in sever hydraulic environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Duncan, J. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2003-03-01

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new “fish-friendly” turbines, and spillway designs and operations, Pacific Northwest National Laboratory (PNNL) scientists have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. This report discusses the development and field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River, which have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  13. Cataclysmic Variable Stars

    Science.gov (United States)

    Hellier, Coel

    2001-01-01

    Cataclysmic variable stars are the most variable stars in the night sky, fluctuating in brightness continually on timescales from seconds to hours to weeks to years. The changes can be recorded using amateur telescopes, yet are also the subject of intensive study by professional astronomers. That study has led to an understanding of cataclysmic variables as binary stars, orbiting so closely that material transfers from one star to the other. The resulting process of accretion is one of the most important in astrophysics. This book presents the first account of cataclysmic variables at an introductory level. Assuming no previous knowledge of the field, it explains the basic principles underlying the variability, while providing an extensive compilation of cataclysmic variable light curves. Aimed at amateur astronomers, undergraduates, and researchers, the main text is accessible to those with no mathematical background, while supplementary boxes present technical details and equations.

  14. Understanding Brown Dwarf Variability

    Science.gov (United States)

    Marley, Mark S.

    2013-01-01

    Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

  15. The nebular variables

    CERN Document Server

    Glasby, John S

    1974-01-01

    The Nebular Variables focuses on the nebular variables and their characteristics. Discussions are organized by type of nebular variable, namely, RW Aurigae stars, T Orionis stars, T Tauri stars, and peculiar nebular objects. Topics range from light variations of the stars to their spectroscopic and physical characteristics, spatial distribution, interaction with nebulosity, and evolutionary features. This volume is divided into four sections and consists of 25 chapters, the first of which provides general information on nebular variables, including their stellar associations and their classifi

  16. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  17. Reconnection conditions for a coaxial plasma gun

    International Nuclear Information System (INIS)

    Berk, H.L.; Hammer, J.H.; Shearer, J.W.

    1982-01-01

    A fluid model for the flow conditions necessary to form a compact torus from the plasma ejected by a coaxial plasma gun is developed. This is done by finding the conditions for which the steady-flow equations break down. Results are found for two cases; variable external flux and variable outer-wall radius

  18. Maximum Likelihood Learning of Conditional MTE Distributions

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2009-01-01

    We describe a procedure for inducing conditional densities within the mixtures of truncated exponentials (MTE) framework. We analyse possible conditional MTE specifications and propose a model selection scheme, based on the BIC score, for partitioning the domain of the conditioning variables....... Finally, experimental results demonstrate the applicability of the learning procedure as well as the expressive power of the conditional MTE distribution....

  19. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  20. Collective variables and dissipation

    International Nuclear Information System (INIS)

    Balian, R.

    1984-09-01

    This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory

  1. Variability: A Pernicious Hypothesis.

    Science.gov (United States)

    Noddings, Nel

    1992-01-01

    The hypothesis of greater male variability in test results is discussed in its historical context, and reasons feminists have objected to the hypothesis are considered. The hypothesis acquires political importance if it is considered that variability results from biological, rather than cultural, differences. (SLD)

  2. Reinforcing Saccadic Amplitude Variability

    Science.gov (United States)

    Paeye, Celine; Madelain, Laurent

    2011-01-01

    Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

  3. POVMs and hidden variables

    International Nuclear Information System (INIS)

    Stairs, Allen

    2007-01-01

    Recent results by Paul Busch and Adan Cabello claim to show that by appealing to POVMs, non-contextual hidden variables can be ruled out in two dimensions. While the results of Busch and Cabello are mathematically correct, interpretive problems render them problematic as no hidden variable proofs

  4. Interdependence Among Organizational Variables

    Science.gov (United States)

    Knowles, M. C.

    1975-01-01

    The interrelationship between a set of organizational variables was investigated at 14 work organizations within a company. The variables were production, quality, costs, job satisfaction of operatives, job satisfaction of supervisors, work anxiety, accidents, absence, labor turnover, and industrial unrest. (Author)

  5. Climatological variability in regional air pollution

    International Nuclear Information System (INIS)

    Shannon, J.D.; Trexler, E.C. Jr.

    1995-01-01

    Although some air pollution modeling studies examine events that have already occurred (e.g., the Chernobyl plume) with relevant meteorological conditions largely known, most pollution modeling studies address expected or potential scenarios for the future. Future meteorological conditions, the major pollutant forcing function other than emissions, are inherently uncertain although much relevant information is contained in past observational data. For convenience in our discussions of regional pollutant variability unrelated to emission changes, we define meteorological variability as short-term (within-season) pollutant variability and climatological variability as year-to-year changes in seasonal averages and accumulations of pollutant variables. In observations and in some of our simulations the effects are confounded because for seasons of two different years both the mean and the within-season character of a pollutant variable may change. Effects of climatological and meteorological variability on means and distributions of air pollution parameters, particularly those related to regional visibility, are illustrated. Over periods of up to a decade climatological variability may mask or overstate improvements resulting from emission controls. The importance of including climatological uncertainties in assessing potential policies, particularly when based partly on calculated source-receptor relationships, is highlighted

  6. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  7. Time, rate, and conditioning.

    Science.gov (United States)

    Gallistel, C R; Gibbon, J

    2000-04-01

    The authors draw together and develop previous timing models for a broad range of conditioning phenomena to reveal their common conceptual foundations: First, conditioning depends on the learning of the temporal intervals between events and the reciprocals of these intervals, the rates of event occurrence. Second, remembered intervals and rates translate into observed behavior through decision processes whose structure is adapted to noise in the decision variables. The noise and the uncertainties consequent on it have both subjective and objective origins. A third feature of these models is their timescale invariance, which the authors argue is a very important property evident in the available experimental data. This conceptual framework is similar to the psychophysical conceptual framework in which contemporary models of sensory processing are rooted. The authors contrast it with the associative conceptual framework.

  8. Eternity Variables to Simulate Specifications

    NARCIS (Netherlands)

    Hesselink, WH; Boiten, EA; Moller, B

    2002-01-01

    Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward

  9. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  10. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  11. Variable-Rate Premiums

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — These interest rates are used to value vested benefits for variable rate premium purposes as described in PBGC's regulation on Premium Rates (29 CFR Part 4006) and...

  12. Variable Pricing Feasibility Assessment

    National Research Council Canada - National Science Library

    2004-01-01

    ...) and Willard Bishop Consulting (Barrington, IL) to evaluate the practicality of using a variable pricing system within DeCA to maintain an average of 30 percent customer savings and lower appropriated fund costs...

  13. Evolution of variable stars

    International Nuclear Information System (INIS)

    Becker, S.A.

    1986-08-01

    Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

  14. Calculus of one variable

    CERN Document Server

    Grossman, Stanley I

    1986-01-01

    Calculus of One Variable, Second Edition presents the essential topics in the study of the techniques and theorems of calculus.The book provides a comprehensive introduction to calculus. It contains examples, exercises, the history and development of calculus, and various applications. Some of the topics discussed in the text include the concept of limits, one-variable theory, the derivatives of all six trigonometric functions, exponential and logarithmic functions, and infinite series.This textbook is intended for use by college students.

  15. Software Testing Requires Variability

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2003-01-01

    Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability....

  16. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  17. Continuous-variable quantum homomorphic signature

    Science.gov (United States)

    Li, Ke; Shang, Tao; Liu, Jian-wei

    2017-10-01

    Quantum cryptography is believed to be unconditionally secure because its security is ensured by physical laws rather than computational complexity. According to spectrum characteristic, quantum information can be classified into two categories, namely discrete variables and continuous variables. Continuous-variable quantum protocols have gained much attention for their ability to transmit more information with lower cost. To verify the identities of different data sources in a quantum network, we propose a continuous-variable quantum homomorphic signature scheme. It is based on continuous-variable entanglement swapping and provides additive and subtractive homomorphism. Security analysis shows the proposed scheme is secure against replay, forgery and repudiation. Even under nonideal conditions, it supports effective verification within a certain verification threshold.

  18. Hardness variability in commercial technologies

    International Nuclear Information System (INIS)

    Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G.

    1994-01-01

    The radiation hardness of commercial Floating Gate 256K E 2 PROMs from a single diffusion lot was observed to vary between 5 to 25 krad(Si) when irradiated at a low dose rate of 64 mrad(Si)/s. Additional variations in E 2 PROM hardness were found to depend on bias condition and failure mode (i.e., inability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E 2 PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SRAMs from each manufacturer varied by less than 20%, but differences between manufacturers are significant. The Qualified Manufacturer's List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies

  19. hmF2 variability over Havana

    International Nuclear Information System (INIS)

    Lazo, B.; Alazo, K.; Rodriguez, M.; Calzadilla, A.

    2003-01-01

    The hmF2 variability over Havana station (Geo. Latitude 23 deg. N, Geo Longitude 278 deg. E; Dip 54.6 deg. N; Modip: 44.8 deg. N) is presented. In this study different solar and seasonal conditions are considered. The results show that, in general, standard deviation of hmF2 is quite irregular and reaches its values at nighttimes hours. Lower and upper quartiles variability has a similar behaviour to IQ variability, showing its higher values at nighttimes too. (author)

  20. Variable selection by lasso-type methods

    Directory of Open Access Journals (Sweden)

    Sohail Chand

    2011-09-01

    Full Text Available Variable selection is an important property of shrinkage methods. The adaptive lasso is an oracle procedure and can do consistent variable selection. In this paper, we provide an explanation that how use of adaptive weights make it possible for the adaptive lasso to satisfy the necessary and almost sufcient condition for consistent variable selection. We suggest a novel algorithm and give an important result that for the adaptive lasso if predictors are normalised after the introduction of adaptive weights, it makes the adaptive lasso performance identical to the lasso.

  1. Visual variability affects early verb learning.

    Science.gov (United States)

    Twomey, Katherine E; Lush, Lauren; Pearce, Ruth; Horst, Jessica S

    2014-09-01

    Research demonstrates that within-category visual variability facilitates noun learning; however, the effect of visual variability on verb learning is unknown. We habituated 24-month-old children to a novel verb paired with an animated star-shaped actor. Across multiple trials, children saw either a single action from an action category (identical actions condition, for example, travelling while repeatedly changing into a circle shape) or multiple actions from that action category (variable actions condition, for example, travelling while changing into a circle shape, then a square shape, then a triangle shape). Four test trials followed habituation. One paired the habituated verb with a new action from the habituated category (e.g., 'dacking' + pentagon shape) and one with a completely novel action (e.g., 'dacking' + leg movement). The others paired a new verb with a new same-category action (e.g., 'keefing' + pentagon shape), or a completely novel category action (e.g., 'keefing' + leg movement). Although all children discriminated novel verb/action pairs, children in the identical actions condition discriminated trials that included the completely novel verb, while children in the variable actions condition discriminated the out-of-category action. These data suggest that - as in noun learning - visual variability affects verb learning and children's ability to form action categories. © 2014 The British Psychological Society.

  2. Heart rate variability in newborns.

    Science.gov (United States)

    Javorka, K; Lehotska, Z; Kozar, M; Uhrikova, Z; Kolarovszki, B; Javorka, M; Zibolen, M

    2017-09-22

    Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympathetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain revealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by changes in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants.

  3. Large errors and severe conditions

    CERN Document Server

    Smith, D L; Van Wormer, L A

    2002-01-01

    Physical parameters that can assume real-number values over a continuous range are generally represented by inherently positive random variables. However, if the uncertainties in these parameters are significant (large errors), conventional means of representing and manipulating the associated variables can lead to erroneous results. Instead, all analyses involving them must be conducted in a probabilistic framework. Several issues must be considered: First, non-linear functional relations between primary and derived variables may lead to significant 'error amplification' (severe conditions). Second, the commonly used normal (Gaussian) probability distribution must be replaced by a more appropriate function that avoids the occurrence of negative sampling results. Third, both primary random variables and those derived through well-defined functions must be dealt with entirely in terms of their probability distributions. Parameter 'values' and 'errors' should be interpreted as specific moments of these probabil...

  4. Cartas de control para monitorear variables multinomiales

    Directory of Open Access Journals (Sweden)

    Luz Marcela Restrepo-Tamayo

    2014-07-01

    Full Text Available Background: The control as a tool for monitoring the quality of a product, allows to study the stability of processes over time, contrasting two hypothesis, which states that the process is in stable condition and the other denies it. Its use has been massive for continuous variables but not for categorical variables, why it is imperative to design such tools for such variables. Objective: To propose two (2 control charts for variables multinomial processes based on the p-value test result for homogeneity of proportions using the chi square test for uniform processing variables and approximation Wilson - Hilferty for variables chi square. Methods: The performance of proposed charts via simulation is estimated considering a Phase II process and considering the first category increments of 2%, 4% and 6% in the control stage. Results: The multinomial control chart using Wilson-Hilferty approximation for variables chi square, from the transformation of value-p, has poor performance compared to the control charts using p-value processing and using chi-square p-value, as they have less ability to detect small changes. Conclusion: We propose two control charts to monitor multinomial variables and once studied via simulation, based on the average run length (ARL and the probability of rejecting the null hypothesis of equal proportions, we recommend the control chart using value-p, or equivalently, the control chart processing using chi square p-value.

  5. Variational Infinite Hidden Conditional Random Fields

    NARCIS (Netherlands)

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin

    2015-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of

  6. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  7. Variable stator radial turbine

    Science.gov (United States)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  8. [Blood pressure variability: clinical interest or simple curiosity?].

    Science.gov (United States)

    Ciaroni, Stefano

    2007-03-14

    Blood pressure variability is a physiological phenomenon influenced by many internal and external factors. This variability could be also influenced by pathological conditions such as arterial hypertension. Two forms must be mainly distinguished: the blood pressure variability at long and short-term. The latter could only be studied by continuous recordings. In this article will be analysed the interest of measuring blood pressure variability, its cardiovascular prognosis and the therapeutic tools when it is increased.

  9. Internal variables in thermoelasticity

    CERN Document Server

    Berezovski, Arkadi

    2017-01-01

    This book describes an effective method for modeling advanced materials like polymers, composite materials and biomaterials, which are, as a rule, inhomogeneous. The thermoelastic theory with internal variables presented here provides a general framework for predicting a material’s reaction to external loading. The basic physical principles provide the primary theoretical information, including the evolution equations of the internal variables. The cornerstones of this framework are the material representation of continuum mechanics, a weak nonlocality, a non-zero extra entropy flux, and a consecutive employment of the dissipation inequality. Examples of thermoelastic phenomena are provided, accompanied by detailed procedures demonstrating how to simulate them.

  10. Resiliencia y variables sociodemograficas

    OpenAIRE

    Calero Martinez, Edgar David

    2015-01-01

    En el presente trabajo se aborda la definición de una de las variables dentro de lo que se denomina Capital psicológico positivo, la Resiliencia, sus principales características y algunas de las variables socio demográficas que en el estudio pretenden ver el nivel de relación existente entre cada una de ellas (indirecta o directamente) en el proceso resiliente de una persona para posteriores discusiones y su implicación dentro de la gestión empresarial y sus direcciones futuras.

  11. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  12. A novel variable selection approach that iteratively optimizes variable space using weighted binary matrix sampling.

    Science.gov (United States)

    Deng, Bai-chuan; Yun, Yong-huan; Liang, Yi-zeng; Yi, Lun-zhao

    2014-10-07

    In this study, a new optimization algorithm called the Variable Iterative Space Shrinkage Approach (VISSA) that is based on the idea of model population analysis (MPA) is proposed for variable selection. Unlike most of the existing optimization methods for variable selection, VISSA statistically evaluates the performance of variable space in each step of optimization. Weighted binary matrix sampling (WBMS) is proposed to generate sub-models that span the variable subspace. Two rules are highlighted during the optimization procedure. First, the variable space shrinks in each step. Second, the new variable space outperforms the previous one. The second rule, which is rarely satisfied in most of the existing methods, is the core of the VISSA strategy. Compared with some promising variable selection methods such as competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MCUVE) and iteratively retaining informative variables (IRIV), VISSA showed better prediction ability for the calibration of NIR data. In addition, VISSA is user-friendly; only a few insensitive parameters are needed, and the program terminates automatically without any additional conditions. The Matlab codes for implementing VISSA are freely available on the website: https://sourceforge.net/projects/multivariateanalysis/files/VISSA/.

  13. INTER-EXAMINER VARIABILITY

    African Journals Online (AJOL)

    Objective: To establish whether inter-examiner variability is still a significant factor for the undergraduate orthopaedic clinical ... D. The scores for each student were tabulated and the range, mean, and pass rate determined for each of the examiners. ... has not the heart to reject the man”, consistently gave higher scores (1).

  14. Several real variables

    CERN Document Server

    Kantorovitz, Shmuel

    2016-01-01

    This undergraduate textbook is based on lectures given by the author on the differential and integral calculus of functions of several real variables. The book has a modern approach and includes topics such as: •The p-norms on vector space and their equivalence •The Weierstrass and Stone-Weierstrass approximation theorems •The differential as a linear functional; Jacobians, Hessians, and Taylor's theorem in several variables •The Implicit Function Theorem for a system of equations, proved via Banach’s Fixed Point Theorem •Applications to Ordinary Differential Equations •Line integrals and an introduction to surface integrals This book features numerous examples, detailed proofs, as well as exercises at the end of sections. Many of the exercises have detailed solutions, making the book suitable for self-study. Several Real Variables will be useful for undergraduate students in mathematics who have completed first courses in linear algebra and analysis of one real variable.

  15. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  16. All Those Independent Variables.

    Science.gov (United States)

    Meacham, Merle L.

    This paper presents a case study of a sixth grade remedial math class which illustrates the thesis that only the "experimental attitude," not the "experimental method," is appropriate in the classroom. The thesis is based on the fact that too many independent variables exist in a classroom situation to allow precise measurement. The case study…

  17. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  18. Tides and Decadal Variability

    Science.gov (United States)

    Ray, Richard D.

    2003-01-01

    This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

  19. An Assessment of the Spatial and Temporal Variability of Biological Responses to Municipal Wastewater Effluent in Rainbow Darter (Etheostoma caeruleum) Collected along an Urban Gradient

    Science.gov (United States)

    Bragg, Leslie M.; Tetreault, Gerald R.; Bahamonde, Paulina A.; Tanna, Rajiv N.; Bennett, Charles J.; McMaster, Mark E.; Servos, Mark R.

    2016-01-01

    Municipal wastewater effluent (MWWE) and its constituents, such as chemicals of emerging concern, pose a potential threat to the sustainability of fish populations by disrupting key endocrine functions in aquatic organisms. While studies have demonstrated changes in biological markers of exposure of aquatic organisms to groups of chemicals of emerging concern, the variability of these markers over time has not been sufficiently described in wild fish species. The aim of this study was to assess the spatial and temporal variability of biological markers in response to MWWE exposure and to test the consistency of these responses between seasons and among years. Rainbow darter (Etheostoma caeruleum) were collected in spring and fall seasons over a 5-year period in the Grand River, Ontario, Canada. In addition to surface water chemistry (nutrients and selected pharmaceuticals), measures were taken across levels of biological organization in rainbow darter. The measurements of hormone production, gonad development, and intersex severity were temporally consistent and suggested impaired reproduction in male fish collected downstream of MWWE outfalls. In contrast, ovarian development and hormone production in females appeared to be influenced more by urbanization than MWWE. Measures of gene expression and somatic indices were highly variable between sites and years, respectively, and were inconclusive in terms of the impacts of MWWE overall. Robust biomonitoring programs must consider these factors in both the design and interpretation of results, especially when spatial and temporal sampling of biological endpoints is limited. Assessing the effects of contaminants and other stressors on fish in watersheds would be greatly enhanced by an approach that considers natural variability in the endpoints being measured. PMID:27776151

  20. An Assessment of the Spatial and Temporal Variability of Biological Responses to Municipal Wastewater Effluent in Rainbow Darter (Etheostoma caeruleum Collected along an Urban Gradient.

    Directory of Open Access Journals (Sweden)

    Meghan L M Fuzzen

    Full Text Available Municipal wastewater effluent (MWWE and its constituents, such as chemicals of emerging concern, pose a potential threat to the sustainability of fish populations by disrupting key endocrine functions in aquatic organisms. While studies have demonstrated changes in biological markers of exposure of aquatic organisms to groups of chemicals of emerging concern, the variability of these markers over time has not been sufficiently described in wild fish species. The aim of this study was to assess the spatial and temporal variability of biological markers in response to MWWE exposure and to test the consistency of these responses between seasons and among years. Rainbow darter (Etheostoma caeruleum were collected in spring and fall seasons over a 5-year period in the Grand River, Ontario, Canada. In addition to surface water chemistry (nutrients and selected pharmaceuticals, measures were taken across levels of biological organization in rainbow darter. The measurements of hormone production, gonad development, and intersex severity were temporally consistent and suggested impaired reproduction in male fish collected downstream of MWWE outfalls. In contrast, ovarian development and hormone production in females appeared to be influenced more by urbanization than MWWE. Measures of gene expression and somatic indices were highly variable between sites and years, respectively, and were inconclusive in terms of the impacts of MWWE overall. Robust biomonitoring programs must consider these factors in both the design and interpretation of results, especially when spatial and temporal sampling of biological endpoints is limited. Assessing the effects of contaminants and other stressors on fish in watersheds would be greatly enhanced by an approach that considers natural variability in the endpoints being measured.

  1. Examining Impulse-Variability in Kicking.

    Science.gov (United States)

    Chappell, Andrew; Molina, Sergio L; McKibben, Jonathon; Stodden, David F

    2016-07-01

    This study examined variability in kicking speed and spatial accuracy to test the impulse-variability theory prediction of an inverted-U function and the speed-accuracy trade-off. Twenty-eight 18- to 25-year-old adults kicked a playground ball at various percentages (50-100%) of their maximum speed at a wall target. Speed variability and spatial error were analyzed using repeated-measures ANOVA with built-in polynomial contrasts. Results indicated a significant inverse linear trajectory for speed variability (p < .001, η2= .345) where 50% and 60% maximum speed had significantly higher variability than the 100% condition. A significant quadratic fit was found for spatial error scores of mean radial error (p < .0001, η2 = .474) and subject-centroid radial error (p < .0001, η2 = .453). Findings suggest variability and accuracy of multijoint, ballistic skill performance may not follow the general principles of impulse-variability theory or the speed-accuracy trade-off.

  2. Fully conditional specification in multivariate imputation

    NARCIS (Netherlands)

    van Buuren, S.; Brand, J. P.L.; Groothuis-Oudshoorn, C. G.M.; Rubin, D. B.

    2006-01-01

    The use of the Gibbs sampler with fully conditionally specified models, where the distribution of each variable given the other variables is the starting point, has become a popular method to create imputations in incomplete multivariate data. The theoretical weakness of this approach is that the

  3. Adapting AIC to conditional model selection

    NARCIS (Netherlands)

    T. van Ommen (Thijs)

    2012-01-01

    textabstractIn statistical settings such as regression and time series, we can condition on observed information when predicting the data of interest. For example, a regression model explains the dependent variables $y_1, \\ldots, y_n$ in terms of the independent variables $x_1, \\ldots, x_n$.

  4. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  5. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  6. Technological Capability's Predictor Variables

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2011-03-01

    Full Text Available The aim of this study was to identify the factors that influence in configuration of the technological capability of companies in sectors with medium-low technological intensity. To achieve the goal proposed in this article a survey was carried out. Based on the framework developed by Lall (1992 which classifies firms in basic, intermediate and advanced level of technological capability; it was found that the predominant technological capability is intermediate, with 83.7% of respondent companies (plastics companies in Brazil. It is believed that the main contribution of this study is the finding that the dependent variable named “Technological Capability” can be explained at a rate of 65% by six variables: development of new processes; selection of the best equipment supplier; sales of internally developed new technology to third parties; design and manufacture of equipment; study of the work methods and perform inventory control; and improvement of product quality.

  7. Variable Kernel Density Estimation

    OpenAIRE

    Terrell, George R.; Scott, David W.

    1992-01-01

    We investigate some of the possibilities for improvement of univariate and multivariate kernel density estimates by varying the window over the domain of estimation, pointwise and globally. Two general approaches are to vary the window width by the point of estimation and by point of the sample observation. The first possibility is shown to be of little efficacy in one variable. In particular, nearest-neighbor estimators in all versions perform poorly in one and two dimensions, but begin to b...

  8. TEC variability over Havana

    International Nuclear Information System (INIS)

    Lazo, B.; Alazo, K.; Rodriguez, M.; Calzadilla, A.

    2003-01-01

    The variability of total electron content (TEC) measured over Havana using ATS-6, SMS-1 and GOES-3 geosynchronous satellite signals has been investigated for low, middle and high solar activity periods from 1974 to 1982. The obtained results show that standard deviation is smooth during nighttime hours and maximum at noon or postnoon hours. Strong solar activity dependence of standard deviation with a maximum values during HSA has been found. (author)

  9. Short timescale variability in the faint sky variability survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V-band variability analysis of the Faint Sky Variability Survey (FSVS). The FSVS combines colour and time variability information, from timescales of 24 minutes to tens of days, down to V = 24. We find that �1% of all point sources are variable along the main sequence reaching �3.5%

  10. Articulatory variability in cluttering.

    Science.gov (United States)

    Hartinger, Mariam; Mooshammer, Christine

    2008-01-01

    In order to investigate the articulatory processes of the hasty and mumbled speech in cluttering, the kinematic variability was analysed by means of electromagnetic midsagittal articulography. In contrast to persons with stuttering, those with cluttering improve their intelligibility by concentrating on their speech task. Variability has always been an important criterion in comparable studies of stuttering and is discussed in terms of the stability of the speech motor system. The aim of the current study was to analyse the spatial and temporal variability in the speech of three persons with cluttering (PWC) and three control speakers. All participants were native speakers of German. The speech material consisted of repetitive CV syllables and loan words such as 'emotionalisieren', because PWC have the severest problems with long words with a complex syllable structure. The results showed a significantly higher coefficient of variation for PWC in loan word production, both in the temporal and in the spatial domain, whereas the means of displacements and durations did not differ between groups. These findings were discussed in terms of the effects of the linguistic complexity, since for the syllable repetition task, no significant differences between PWC and controls were found. Copyright 2008 S. Karger AG, Basel.

  11. Impact of Subsurface Temperature Variability on Meteorological Variability: An AGCM Study

    Science.gov (United States)

    Mahanama, S. P.; Koster, R. D.; Liu, P.

    2006-05-01

    Anomalous atmospheric conditions can lead to surface temperature anomalies, which in turn can lead to temperature anomalies deep in the soil. The deep soil temperature (and the associated ground heat content) has significant memory -- the dissipation of a temperature anomaly may take weeks to months -- and thus deep soil temperature may contribute to the low frequency variability of energy and water variables elsewhere in the system. The memory may even provide some skill to subseasonal and seasonal forecasts. This study uses two long-term AGCM experiments to isolate the contribution of deep soil temperature variability to variability elsewhere in the climate system. The first experiment consists of a standard ensemble of AMIP-type simulations, simulations in which the deep soil temperature variable is allowed to interact with the rest of the system. In the second experiment, the coupling of the deep soil temperature to the rest of the climate system is disabled -- at each grid cell, the local climatological seasonal cycle of deep soil temperature (as determined from the first experiment) is prescribed. By comparing the variability of various atmospheric quantities as generated in the two experiments, we isolate the contribution of interactive deep soil temperature to that variability. The results show that interactive deep soil temperature contributes significantly to surface temperature variability. Interactive deep soil temperature, however, reduces the variability of the hydrological cycle (evaporation and precipitation), largely because it allows for a negative feedback between evaporation and temperature.

  12. Globally exponential stability and periodic solutions of CNNS with variable coefficients and variable delays

    International Nuclear Information System (INIS)

    Liu Haifei; Wang Li

    2006-01-01

    In this Letter, by using the inequality method and the Lyapunov functional method, we analyze the globally exponential stability and the existence of periodic solutions of a class of cellular neutral networks with delays and variable coefficients. Some simple and new sufficient conditions ensuring the existence and uniqueness of globally exponential stability of periodic solutions for cellular neutral networks with variable coefficients and delays are obtained. In addition, one example is also worked out to illustrate our theory

  13. Globally exponential stability and periodic solutions of CNNS with variable coefficients and variable delays

    Energy Technology Data Exchange (ETDEWEB)

    Liu Haifei [School of Management and Engineering, Nanjing University, Nanjing 210093 (China)]. E-mail: hfliu80@126.com; Wang Li [School of Management and Engineering, Nanjing University, Nanjing 210093 (China)

    2006-09-15

    In this Letter, by using the inequality method and the Lyapunov functional method, we analyze the globally exponential stability and the existence of periodic solutions of a class of cellular neutral networks with delays and variable coefficients. Some simple and new sufficient conditions ensuring the existence and uniqueness of globally exponential stability of periodic solutions for cellular neutral networks with variable coefficients and delays are obtained. In addition, one example is also worked out to illustrate our theory.

  14. Weighting Mean and Variability during Confidence Judgments

    Science.gov (United States)

    de Gardelle, Vincent; Mamassian, Pascal

    2015-01-01

    Humans can not only perform some visual tasks with great precision, they can also judge how good they are in these tasks. However, it remains unclear how observers produce such metacognitive evaluations, and how these evaluations might be dissociated from the performance in the visual task. Here, we hypothesized that some stimulus variables could affect confidence judgments above and beyond their impact on performance. In a motion categorization task on moving dots, we manipulated the mean and the variance of the motion directions, to obtain a low-mean low-variance condition and a high-mean high-variance condition with matched performances. Critically, in terms of confidence, observers were not indifferent between these two conditions. Observers exhibited marked preferences, which were heterogeneous across individuals, but stable within each observer when assessed one week later. Thus, confidence and performance are dissociable and observers’ confidence judgments put different weights on the stimulus variables that limit performance. PMID:25793275

  15. About hidden influence of predictor variables: Suppressor and mediator variables

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2013-01-01

    Full Text Available In this paper procedure for researching hidden influence of predictor variables in regression models and depicting suppressor variables and mediator variables is shown. It is also shown that detection of suppressor variables and mediator variables could provide refined information about the research problem. As an example for applying this procedure, relation between Atlantic atmospheric centers and air temperature and precipitation amount in Serbia is chosen. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  16. Ocean outfall off Mangalore, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Chandramohan, P.; Raju, N.S.N.; Pathak, K.C.

    Various industries like refineries, petrochemicals, thermal power, iron and steel, copper smelter, nylon and resins, etc. are coming up along the coastal belt of India. They generally intend to discharge the effluent, brine and warm water from...

  17. Physical oceanographic investigation procedure for a sea - Outfall project

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.

    to the ocean and other resources in a way which negates their destruction but permits maximum utilization. Even though the coastal water body is the most utilized medium for waste disposal, the behaviour of all pollutants is not adequately understood...

  18. Use of tracers for locating and designing sea outfalls

    International Nuclear Information System (INIS)

    Gauthier, M.; Quetin, B.

    1976-01-01

    Various tracers are used for investigating the propagation of substances in solution or suspension (radioactive, biological, chemical substances and floats). Floats and dyes are the most employed. The main problems associated with the use of such tracers and data interpretation are discussed and it is shown how effective quantitative data can be obtained, especially as regards estimation of turbulent diffusion parameters and identification of suitable dispersion methods for purposes of determining pollutant concentration and areas affected thereby [fr

  19. Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

    Science.gov (United States)

    Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

    2017-09-13

    Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects

  20. Variability of the Wind Turbine Power Curve

    Directory of Open Access Journals (Sweden)

    Mahesh M. Bandi

    2016-09-01

    Full Text Available Wind turbine power curves are calibrated by turbine manufacturers under requirements stipulated by the International Electrotechnical Commission to provide a functional mapping between the mean wind speed v ¯ and the mean turbine power output P ¯ . Wind plant operators employ these power curves to estimate or forecast wind power generation under given wind conditions. However, it is general knowledge that wide variability exists in these mean calibration values. We first analyse how the standard deviation in wind speed σ v affects the mean P ¯ and the standard deviation σ P of wind power. We find that the magnitude of wind power fluctuations scales as the square of the mean wind speed. Using data from three planetary locations, we find that the wind speed standard deviation σ v systematically varies with mean wind speed v ¯ , and in some instances, follows a scaling of the form σ v = C × v ¯ α ; C being a constant and α a fractional power. We show that, when applicable, this scaling form provides a minimal parameter description of the power curve in terms of v ¯ alone. Wind data from different locations establishes that (in instances when this scaling exists the exponent α varies with location, owing to the influence of local environmental conditions on wind speed variability. Since manufacturer-calibrated power curves cannot account for variability influenced by local conditions, this variability translates to forecast uncertainty in power generation. We close with a proposal for operators to perform post-installation recalibration of their turbine power curves to account for the influence of local environmental factors on wind speed variability in order to reduce the uncertainty of wind power forecasts. Understanding the relationship between wind’s speed and its variability is likely to lead to lower costs for the integration of wind power into the electric grid.

  1. Gaussian Mixture Model of Heart Rate Variability

    Science.gov (United States)

    Costa, Tommaso; Boccignone, Giuseppe; Ferraro, Mario

    2012-01-01

    Heart rate variability (HRV) is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters. PMID:22666386

  2. Contextuality in canonical systems of random variables

    Science.gov (United States)

    Dzhafarov, Ehtibar N.; Cervantes, Víctor H.; Kujala, Janne V.

    2017-10-01

    Random variables representing measurements, broadly understood to include any responses to any inputs, form a system in which each of them is uniquely identified by its content (that which it measures) and its context (the conditions under which it is recorded). Two random variables are jointly distributed if and only if they share a context. In a canonical representation of a system, all random variables are binary, and every content-sharing pair of random variables has a unique maximal coupling (the joint distribution imposed on them so that they coincide with maximal possible probability). The system is contextual if these maximal couplings are incompatible with the joint distributions of the context-sharing random variables. We propose to represent any system of measurements in a canonical form and to consider the system contextual if and only if its canonical representation is contextual. As an illustration, we establish a criterion for contextuality of the canonical system consisting of all dichotomizations of a single pair of content-sharing categorical random variables. This article is part of the themed issue `Second quantum revolution: foundational questions'.

  3. Understanding Solar Cycle Variability

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2017-07-10

    The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

  4. Punctors: A Pragmatic Variable.

    Science.gov (United States)

    Vincent, Diane; Sankoff, David

    1992-01-01

    Analysis of the distribution of punctors, a class of markers commonly classified as nervous tics, fillers, or signs of hesitation, in one corpus of French is presented. Some aspects of their conditioning are explained in terms of the interaction of etymological, discursive, syntactic, and social constraints. (Author/MSE)

  5. Climate variability and change

    International Nuclear Information System (INIS)

    Manton, M.

    2006-01-01

    When Australia's climate should not be definite barrier to the population reaching 30 million by 2050, it is recognised that our climate has limited the development of the nation over the past 200 years. Indeed in 1911, based on a comparison of the climate and development between the US and Australia. Griffith Taylor predicted that Australia's population would be 19 million at the end of the 20th century, which is a pretty good 90-year forecast. The climate constraint is not only due to much of the country being semi-arid with an annual rainfall below 400 millimetres, but also due to the large year-to-year variability of rainfall across the country

  6. The effect of virtual reality on gait variability.

    Science.gov (United States)

    Katsavelis, Dimitrios; Mukherjee, Mukul; Decker, Leslie; Stergiou, Nicholas

    2010-07-01

    Optic Flow (OF) plays an important role in human locomotion and manipulation of OF characteristics can cause changes in locomotion patterns. The purpose of the study was to investigate the effect of the velocity of optic flow on the amount and structure of gait variability. Each subject underwent four conditions of treadmill walking at their self-selected pace. In three conditions the subjects walked in an endless virtual corridor, while a fourth control condition was also included. The three virtual conditions differed in the speed of the optic flow displayed as follows--same speed (OFn), faster (OFf), and slower (OFs) than that of the treadmill. Gait kinematics were tracked with an optical motion capture system. Gait variability measures of the hip, knee and ankle range of motion and stride interval were analyzed. Amount of variability was evaluated with linear measures of variability--coefficient of variation, while structure of variability i.e., its organization over time, were measured with nonlinear measures--approximate entropy and detrended fluctuation analysis. The linear measures of variability, CV, did not show significant differences between Non-VR and VR conditions while nonlinear measures of variability identified significant differences at the hip, ankle, and in stride interval. In response to manipulation of the optic flow, significant differences were observed between the three virtual conditions in the following order: OFn greater than OFf greater than OFs. Measures of structure of variability are more sensitive to changes in gait due to manipulation of visual cues, whereas measures of the amount of variability may be concealed by adaptive mechanisms. Visual cues increase the complexity of gait variability and may increase the degrees of freedom available to the subject. Further exploration of the effects of optic flow manipulation on locomotion may provide us with an effective tool for rehabilitation of subjects with sensorimotor issues.

  7. Statistical variability of hydro-meteorological variables as indicators ...

    African Journals Online (AJOL)

    Statistical variability of hydro-meteorological variables as indicators of climate change in north-east Sokoto-Rima basin, Nigeria. ... water resources development including water supply project, agriculture and tourism in the study area. Key word: Climate change, Climatic variability, Actual evapotranspiration, Global warming ...

  8. Search for rapid variability of 53 Cam

    International Nuclear Information System (INIS)

    Zverko, J.

    1982-01-01

    Photoelectric observations of magnetic Ap star 53 Cam made at the Skalnate Pleso Observatory in 1978 and 1979 are analyzed from the point of view of rapid variability. The observations were made with an intermediate passband filter, effective wavelength 526 nm. Besides the differences msub(53Cam)-msub(Comp), the behaviour was also investigated of the deflections for the comparison star during the observation runs. A strong correlation between the behaviour of the comparison and variable star light curve was found and the appearance differs from night to night depending on atmospheric conditions. Each observation run is analyzed in detail and it was concluded that all observed variations are only apparent and due to the variability of atmospheric extinction above the observation site. (author)

  9. Variable Speed Limit (VSL) - Best Management Practice [Summary

    Science.gov (United States)

    2012-01-01

    In variable speed limit (VSL) zones, the speed : limit changes in response to traffic congestion, : adverse weather, or road conditions. VSL zones are : often highly automated and have been employed : successfully in several U.S. and European : locat...

  10. Examining impulse-variability in overarm throwing.

    Science.gov (United States)

    Urbin, M A; Stodden, David; Boros, Rhonda; Shannon, David

    2012-01-01

    The purpose of this study was to examine variability in overarm throwing velocity and spatial output error at various percentages of maximum to test the prediction of an inverted-U function as predicted by impulse-variability theory and a speed-accuracy trade-off as predicted by Fitts' Law Thirty subjects (16 skilled, 14 unskilled) were instructed to throw a tennis ball at seven percentages of their maximum velocity (40-100%) in random order (9 trials per condition) at a target 30 feet away. Throwing velocity was measured with a radar gun and interpreted as an index of overall systemic power output. Within-subject throwing velocity variability was examined using within-subjects repeated-measures ANOVAs (7 repeated conditions) with built-in polynomial contrasts. Spatial error was analyzed using mixed model regression. Results indicated a quadratic fit with variability in throwing velocity increasing from 40% up to 60%, where it peaked, and then decreasing at each subsequent interval to maximum (p < .001, η2 = .555). There was no linear relationship between speed and accuracy. Overall, these data support the notion of an inverted-U function in overarm throwing velocity variability as both skilled and unskilled subjects approach maximum effort. However, these data do not support the notion of a speed-accuracy trade-off. The consistent demonstration of an inverted-U function associated with systemic power output variability indicates an enhanced capability to regulate aspects of force production and relative timing between segments as individuals approach maximum effort, even in a complex ballistic skill.

  11. A geometric model for magnetizable bodies with internal variables

    Directory of Open Access Journals (Sweden)

    Restuccia, L

    2005-11-01

    Full Text Available In a geometrical framework for thermo-elasticity of continua with internal variables we consider a model of magnetizable media previously discussed and investigated by Maugin. We assume as state variables the magnetization together with its space gradient, subjected to evolution equations depending on both internal and external magnetic fields. We calculate the entropy function and necessary conditions for its existence.

  12. Variability in yield of faba beans (Vicia faba L.)

    NARCIS (Netherlands)

    Grashoff, C.

    1992-01-01

    Yield variability is one of the major problems in growing faba beans. In this thesis, the effect of water supply pattern on yield variability of the crop is studied with experiments in the field and under controlled conditions, and with a simulation model. In a series of field experiments,

  13. Assessment of genetic variability of maize inbred lines and their ...

    African Journals Online (AJOL)

    Assessment of genetic variability of maize inbred lines and their hybrids under normal and drought conditions. ... Nigeria Agricultural Journal ... Analysis of variance revealed significant differences for most of the characters under study which indicates the presence of sufficient amount of variability offering ample scope for ...

  14. Quantum walk with one variable absorbing boundary

    International Nuclear Information System (INIS)

    Wang, Feiran; Zhang, Pei; Wang, Yunlong; Liu, Ruifeng; Gao, Hong; Li, Fuli

    2017-01-01

    Quantum walks constitute a promising ingredient in the research on quantum algorithms; consequently, exploring different types of quantum walks is of great significance for quantum information and quantum computation. In this study, we investigate the progress of quantum walks with a variable absorbing boundary and provide an analytical solution for the escape probability (the probability of a walker that is not absorbed by the boundary). We simulate the behavior of escape probability under different conditions, including the reflection coefficient, boundary location, and initial state. Moreover, it is also meaningful to extend our research to the situation of continuous-time and high-dimensional quantum walks. - Highlights: • A novel scheme about quantum walk with variable boundary is proposed. • The analytical results of the survival probability from the absorbing boundary. • The behavior of survival probability under different boundary conditions. • The influence of different initial coin states on the survival probability.

  15. Condition Indicators for Gearbox Condition Monitoring Systems

    Directory of Open Access Journals (Sweden)

    P. Večeř

    2005-01-01

    Full Text Available Condition monitoring systems for manual transmissions based on vibration diagnostics are widely applied in industry. The systems deal with various condition indicators, most of which are focused on a specific type of gearbox fault. Frequently used condition indicators (CIs are described in this paper. The ability of a selected condition indicator to describe the degree of gearing wear was tested using vibration signals acquired during durability testing of manual transmission with helical gears. 

  16. The Performance of Variable Annuities

    OpenAIRE

    Michael J. McNamara; Henry R. Oppenheimer

    1991-01-01

    Variable annuities have become increasingly important in retirement plans. This paper provides an examination of the investment performance of variable annuities for the period year-end 1973 to year-end 1988. Returns, risk, and selectivity measures are analyzed for the sample of annuities, for individual variable annuities, and for subsamples of annuities with similar portfolio size and turnover. While the investment returns of variable annuities were greater than inflation over the period, t...

  17. Preservice Teachers' Understanding of Variable

    Science.gov (United States)

    Brown, Sue; Bergman, Judy

    2013-01-01

    This study examines the research on middle school students' understanding of variables and explores preservice elementary and middle school teachers' knowledge of variables. According to research studies, middle school students have limited understanding of variables. Many studies have examined the performance of middle school students and offered…

  18. Determination of Correlation for Extreme Metocean Variables

    Directory of Open Access Journals (Sweden)

    Nizamani Zafarullah

    2017-01-01

    Full Text Available Metocean environmental load includes wind, wave and currents. Offshore structures are designed for two environmental load design conditions i.e. extreme and operational load conditions of environmental loads are evaluated. The ccorrelation between load variables using Joint probability distribution, Pearson correlation coefficient and Spearman’s rank correlation coefficients methods in Peninsular Malaysia (PM, Sabah and Sarawak are computed. Joint probability distribution method is considered as a reliable method among three different methods to determine the relationship between load variables. The PM has good correlation between the wind-wave and wave-current; Sabah has both strong relationships of wind-wave and wind-current with 50 year return period; Sarawak has good correlation between wind and current in both 50 years and 100 years return period. Since Sabah has good correlation between the associated load variables, no matter in 50 years or 100 years of return period of load combination. Thus, method 1 of ISO 19901-1, specimen provides guideline for metocean loading conditions, can be adopted for design for offshore structure in Sabah. However, due to weak correlations in PM and Sarawak, this method cannot be applied and method 2, which is current practice in offshore industry, should continueto be used.

  19. Visual cues and listening effort: individual variability.

    Science.gov (United States)

    Picou, Erin M; Ricketts, Todd A; Hornsby, Benjamin W Y

    2011-10-01

    To investigate the effect of visual cues on listening effort as well as whether predictive variables such as working memory capacity (WMC) and lipreading ability affect the magnitude of listening effort. Twenty participants with normal hearing were tested using a paired-associates recall task in 2 conditions (quiet and noise) and 2 presentation modalities (audio only [AO] and auditory-visual [AV]). Signal-to-noise ratios were adjusted to provide matched speech recognition across audio-only and AV noise conditions. Also measured were subjective perceptions of listening effort and 2 predictive variables: (a) lipreading ability and (b) WMC. Objective and subjective results indicated that listening effort increased in the presence of noise, but on average the addition of visual cues did not significantly affect the magnitude of listening effort. Although there was substantial individual variability, on average participants who were better lipreaders or had larger WMCs demonstrated reduced listening effort in noise in AV conditions. Overall, the results support the hypothesis that integrating auditory and visual cues requires cognitive resources in some participants. The data indicate that low lipreading ability or low WMC is associated with relatively effortful integration of auditory and visual information in noise.

  20. Conspicuous plumage colours are highly variable.

    Science.gov (United States)

    Delhey, Kaspar; Szecsenyi, Beatrice; Nakagawa, Shinichi; Peters, Anne

    2017-01-25

    Elaborate ornamental traits are often under directional selection for greater elaboration, which in theory should deplete underlying genetic variation. Despite this, many ornamental traits appear to remain highly variable and how this essential variation is maintained is a key question in evolutionary biology. One way to address this question is to compare differences in intraspecific variability across different types of traits to determine whether high levels of variation are associated with specific trait characteristics. Here we assess intraspecific variation in more than 100 plumage colours across 55 bird species to test whether colour variability is linked to their level of elaboration (indicated by degree of sexual dichromatism and conspicuousness) or their condition dependence (indicated by mechanism of colour production). Conspicuous colours had the highest levels of variation and conspicuousness was the strongest predictor of variability, with high explanatory power. After accounting for this, there were no significant effects of sexual dichromatism or mechanisms of colour production. Conspicuous colours may entail higher production costs or may be more sensitive to disruptions during production. Alternatively, high variability could also be related to increased perceptual difficulties inherent to discriminating highly elaborate colours. Such psychophysical effects may constrain the exaggeration of animal colours. © 2017 The Author(s).

  1. Variable angle correlation spectroscopy

    International Nuclear Information System (INIS)

    Lee, Y.K.; Lawrence Berkeley Lab., CA

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13 C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system

  2. Integration i flere variable

    DEFF Research Database (Denmark)

    Markvorsen, Steen

    2010-01-01

    Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum-integraler. Udgangspu......Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum......-integralerne. Undervejs introduceres \\texttt{Integrator8}. Det er en pakke med Maple procedurer, som er udviklet specielt med henblik på eksempelbaseret visuel læring af de indledende integrationsbegreber og deres mangfoldige anvendelser. Vi giver eksempler på, hvordan integration i flere variable anvendes til beregning...... og forståelse af rumfang, vægt, massemidtpunkter, inertimomenter, kraftmomenter, etc. Flowkurverne for et givet vektorfelt i rummet kan findes og visualiseres med \\texttt{Integrator8}. De vigtige begreber divergens og rotation for et vektorfelt fremtræder derved som naturlige størrelser til...

  3. Climate variability and climate change

    International Nuclear Information System (INIS)

    Rind, D.

    1990-01-01

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century

  4. Climate variability and climate change

    International Nuclear Information System (INIS)

    Rind, D.

    1991-01-01

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century. 19 refs.; 3 figs.; 2 tabs

  5. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  6. Study of the electron density variability at fixed heights over San Juan and Tucuman

    International Nuclear Information System (INIS)

    Ezquer, R.G.; Mosert, M.; Radicella, S.M.; Jadur, C.A.

    2002-01-01

    The electron density (N) variability at fixed heights in the bottomside N profile over two Argentinean stations is presented. In this first study different solar conditions and some seasons are considered. The NHPC and CARP programs were used. The results show that, in general, for nighttime conditions the variability increases above 250 km. By noon the variability decreases with increasing the solar activity. At fixed heights, in general, the variability is larger by night than by day above 220 km. (author)

  7. Variable operator technique and the min-max theorem

    Indian Academy of Sciences (India)

    We investigate a variation method where the trial function is generated from the application of a variable operator on a reference function. Two conditions are identified, one for obtaining a maximum and another for a minimum. Although the conditions are easy to understand, the overall formulation is somewhat unusual as ...

  8. Promoting Response Variability and Stimulus Generalization in Martial Arts Training

    Science.gov (United States)

    Harding, Jay W.; Wacker, David P.; Berg, Wendy K.; Rick, Gary; Lee, John F.

    2004-01-01

    The effects of reinforcement and extinction on response variability and stimulus generalization in the punching and kicking techniques of 2 martial arts students were evaluated across drill and sparring conditions. During both conditions, the students were asked to demonstrate different techniques in response to an instructor's punching attack.…

  9. Skin Condition Finder

    Science.gov (United States)

    ... SKIN CONDITIONS HEALTH TOPICS FOR PROFESSIONALS Rash and Skin Condition Finder 1 Select Age Group Infant Child ... Toe Toe Webspace Toe Nail CLOSE About the Skin Condition Finder Have a health question or concern? ...

  10. Benchmarking Variable Selection in QSAR.

    Science.gov (United States)

    Eklund, Martin; Norinder, Ulf; Boyer, Scott; Carlsson, Lars

    2012-02-01

    Variable selection is important in QSAR modeling since it can improve model performance and transparency, as well as reduce the computational cost of model fitting and predictions. Which variable selection methods that perform well in QSAR settings is largely unknown. To address this question we, in a total of 1728 benchmarking experiments, rigorously investigated how eight variable selection methods affect the predictive performance and transparency of random forest models fitted to seven QSAR datasets covering different endpoints, descriptors sets, types of response variables, and number of chemical compounds. The results show that univariate variable selection methods are suboptimal and that the number of variables in the benchmarked datasets can be reduced with about 60 % without significant loss in model performance when using multivariate adaptive regression splines MARS and forward selection. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Saddlepoint Approximations in Conditional Inference

    Science.gov (United States)

    1990-06-11

    Then the inverse transform can be written as (%, Y) = (T, q(T, Z)) for some function q. When the transform is not one to one, the domain should be...general regularity conditions described at the beginning of this section hold and that the solution t1 in (9) exists. Denote the inverse transform by (X, Y...density hn(t 0 l z) are desired. Then the inverse transform (Y, ) = (T, q(T, Z)) exists and the variable v in the cumulant generating function K(u, v

  12. HOW NORMAL IS VARIABLE, OR HOW VARIABLE IS NORMAL

    NARCIS (Netherlands)

    TOUWEN, BCL

    Variability is an important property of the central nervous system, and it shows characteristic changes during infancy and childhood. The large amount of variations in the performance of sensomotor functions in infancy is called indiscriminate or primary variability. During toddling age the child

  13. Photometric Variability in the Faint Sky Variability Survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2005-01-01

    The Faint Sky Variability Survey (FSVS) is aimed at finding photometric and/or astrometric variable objects between 16th and 24th mag on time-scales between tens of minutes and years with photometric precisions ranging from 3 millimag to 0.2 mag. An area of ~23 deg2, located at mid and

  14. How well do financial and macroeconomic variables predict stock returns

    DEFF Research Database (Denmark)

    Rasmussen, Anne-Sofie Reng

    Recent evidence of mean reversion in stock returns has led to an explosion in the development of forecasting variables. This paper evaluates the relative performance of these many variables in both time-series and cross-sectional setups. We collect the different measures and compare their forecas......Recent evidence of mean reversion in stock returns has led to an explosion in the development of forecasting variables. This paper evaluates the relative performance of these many variables in both time-series and cross-sectional setups. We collect the different measures and compare...... their forecasting ability for stock returns, and we examine the forecasting variables' ability to reduce pricing errors in the conditional C-CAPM. A key result of the analysis is that the traditional pricedividend ratio performs surprisingly well compared to the many new forecasting variables. We also find...

  15. High efficiency, variable geometry, centrifugal cryogenic pump

    International Nuclear Information System (INIS)

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-01-01

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions

  16. Conditional Density Approximations with Mixtures of Polynomials

    DEFF Research Database (Denmark)

    Varando, Gherardo; López-Cruz, Pedro L.; Nielsen, Thomas Dyhre

    2015-01-01

    Mixtures of polynomials (MoPs) are a non-parametric density estimation technique especially designed for hybrid Bayesian networks with continuous and discrete variables. Algorithms to learn one- and multi-dimensional (marginal) MoPs from data have recently been proposed. In this paper we introduce...... two methods for learning MoP approximations of conditional densities from data. Both approaches are based on learning MoP approximations of the joint density and the marginal density of the conditioning variables, but they differ as to how the MoP approximation of the quotient of the two densities...

  17. Bedform response to flow variability

    Science.gov (United States)

    Nelson, J.M.; Logan, B.L.; Kinzel, P.J.; Shimizu, Y.; Giri, S.; Shreve, R.L.; McLean, S.R.

    2011-01-01

    Laboratory observations and computational results for the response of bedform fields to rapid variations in discharge are compared and discussed. The simple case considered here begins with a relatively low discharge over a flat bed on which bedforms are initiated, followed by a short high-flow period with double the original discharge, during which the morphology of the bedforms adjusts, followed in turn by a relatively long period of the original low discharge. For the grain size and hydraulic conditions selected, the Froude number remains subcritical during the experiment, and sediment moves predominantly as bedload. Observations show rapid development of quasi-two-dimensional bedforms during the initial period of low flow with increasing wavelength and height over the initial low-flow period. When the flow increases, the bedforms rapidly increase in wavelength and height, as expected from other empirical results. When the flow decreases back to the original discharge, the height of the bedforms quickly decreases in response, but the wavelength decreases much more slowly. Computational results using an unsteady two-dimensional flow model coupled to a disequilibrium bedload transport model for the same conditions simulate the formation and initial growth of the bedforms fairly accurately and also predict an increase in dimensions during the high-flow period. However, the computational model predicts a much slower rate of wavelength increase, and also performs less accurately during the final low-flow period, where the wavelength remains essentially constant, rather than decreasing. In addition, the numerical results show less variability in bedform wavelength and height than the measured values; the bedform shape is also somewhat different. Based on observations, these discrepancies may result from the simplified model for sediment particle step lengths used in the computational approach. Experiments show that the particle step length varies spatially and

  18. Phenotypic Variability in the Coccolithophore Emiliania huxleyi.

    Science.gov (United States)

    Blanco-Ameijeiras, Sonia; Lebrato, Mario; Stoll, Heather M; Iglesias-Rodriguez, Debora; Müller, Marius N; Méndez-Vicente, Ana; Oschlies, Andreas

    2016-01-01

    Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3) containing traces of other elements (i.e. Sr and Mg). Their associated carbon export from the euphotic zone to the oceans' interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean.

  19. Phenotypic Variability in the Coccolithophore Emiliania huxleyi.

    Directory of Open Access Journals (Sweden)

    Sonia Blanco-Ameijeiras

    Full Text Available Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3 containing traces of other elements (i.e. Sr and Mg. Their associated carbon export from the euphotic zone to the oceans' interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean.

  20. Nurse working conditions and patient safety outcomes.

    Science.gov (United States)

    Stone, Patricia W; Mooney-Kane, Cathy; Larson, Elaine L; Horan, Teresa; Glance, Laurent G; Zwanziger, Jack; Dick, Andrew W

    2007-06-01

    System approaches, such as improving working conditions, have been advocated to improve patient safety. However, the independent effect of many working condition variables on patient outcomes is unknown. To examine effects of a comprehensive set of working conditions on elderly patient safety outcomes in intensive care units. Observational study, with patient outcome data collected using the National Nosocomial Infection Surveillance system protocols and Medicare files. Several measures of health status and fixed setting characteristics were used to capture distinct dimensions of patient severity of illness and risk for disease. Working condition variables included organizational climate measured by nurse survey; objective measures of staffing, overtime, and wages (derived from payroll data); and hospital profitability and magnet accreditation. The sample comprised 15,846 patients in 51 adult intensive care units in 31 hospitals depending on the outcome analyzed; 1095 nurses were surveyed. Central line associated bloodstream infections (CLBSI), ventilator-associated pneumonia, catheter-associated urinary tract infections, 30-day mortality, and decubiti. Units with higher staffing had lower incidence of CLBSI, ventilator-associated pneumonia, 30-day mortality, and decubiti (P working conditions were associated with all outcomes measured. Improving working conditions will most likely promote patient safety. Future researchers and policymakers should consider a broad set of working condition variables.

  1. Eliciting conditional and unconditional rank correlations from conditional probabilities

    International Nuclear Information System (INIS)

    Morales, O.; Kurowicka, D.; Roelen, A.

    2008-01-01

    Causes of uncertainties may be interrelated and may introduce dependencies. Ignoring these dependencies may lead to large errors. A number of graphical models in probability theory such as dependence trees, vines and (continuous) Bayesian belief nets [Cooke RM. Markov and entropy properties of tree and vine-dependent variables. In: Proceedings of the ASA section on Bayesian statistical science, 1997; Kurowicka D, Cooke RM. Distribution-free continuous Bayesian belief nets. In: Proceedings of mathematical methods in reliability conference, 2004; Bedford TJ, Cooke RM. Vines-a new graphical model for dependent random variables. Ann Stat 2002; 30(4):1031-68; Kurowicka D, Cooke RM. Uncertainty analysis with high dimensional dependence modelling. New York: Wiley; 2006; Hanea AM, et al. Hybrid methods for quantifying and analyzing Bayesian belief nets. In: Proceedings of the 2005 ENBIS5 conference, 2005; Shachter RD, Kenley CR. Gaussian influence diagrams. Manage Sci 1998; 35(5) .] have been developed to capture dependencies between random variables. The input for these models are various marginal distributions and dependence information, usually in the form of conditional rank correlations. Often expert elicitation is required. This paper focuses on dependence representation, and dependence elicitation. The techniques presented are illustrated with an application from aviation safety

  2. CADDIS Volume 4. Data Analysis: Advanced Analyses - Controlling for Natural Variability

    Science.gov (United States)

    Methods for controlling natural variability, predicting environmental conditions from biological observations method, biological trait data, species sensitivity distributions, propensity scores, Advanced Analyses of Data Analysis references.

  3. CADDIS Volume 4. Data Analysis: Advanced Analyses - Controlling for Natural Variability: SSD Plot Diagrams

    Science.gov (United States)

    Methods for controlling natural variability, predicting environmental conditions from biological observations method, biological trait data, species sensitivity distributions, propensity scores, Advanced Analyses of Data Analysis references.

  4. Maximal Inequalities for Dependent Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jorgensen, Jorgen

    2016-01-01

    Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

  5. Soil variability in mountain areas

    OpenAIRE

    Zanini, E.; Freppaz, M.; Stanchi, S.; Bonifacio, E.; Egli, M.

    2015-01-01

    The high spatial variability of soils is a relevant issue at local and global scales, and determines the complexity of soil ecosystem functions and services. This variability derives from strong dependencies of soil ecosystems on parent materials, climate, relief and biosphere, including human impact. Although present in all environments, the interactions of soils with these forming factors are particularly striking in mountain areas.

  6. Speed control variable rate irrigation

    Science.gov (United States)

    Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

  7. Delta Scuti variables. Lecture 6

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    The class of variables near or on the upper main sequence, the delta Scuti variables, are not only the usual ones about the masses, radii, and luminosities, but also the age, rotation, element diffusion to change the surface layer composition, the occurance of convection and the presence of radial and nonradial pulsation modes

  8. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  9. THE VARIABILITY OF INTERLANGUAGE USE

    African Journals Online (AJOL)

    www

    Variability is evident in the interlanguage grammars of all L2 learners, irrespective of their levels of proficiency; their interlanguage use is characterised by the variable occurrence of target L2 forms, and the .... instruction and negative feedback to discover that their hypotheses about the L2 are incorrect. 4.1. Krashen's view.

  10. Independent SU(2)-loop variables

    International Nuclear Information System (INIS)

    Loll, R.

    1991-04-01

    We give a reduction procedure for SU(2)-trace variables and introduce a complete set of indepentent, gauge-invariant and almost local loop variables for the configuration space of SU(2)-lattice gauge theory in 2+1 dimensions. (orig.)

  11. Operant Variability: Procedures and Processes

    Science.gov (United States)

    Machado, Armando; Tonneau, Francois

    2012-01-01

    Barba's (2012) article deftly weaves three main themes in one argument about operant variability. From general theoretical considerations on operant behavior (Catania, 1973), Barba derives methodological guidelines about response differentiation and applies them to the study of operant variability. In the process, he uncovers unnoticed features of…

  12. Betting on conditionals

    OpenAIRE

    Politzer , Guy; Over , David P; Baratgin , Jean

    2010-01-01

    A study is reported testing two hypotheses about a close parallel relation between indicative conditionals, if A then B, and conditional bets, I bet you that if A then B. The first is that both the indicative conditional and the conditional bet are related to the conditional probability, P(B|A). The second is that de Finetti's three-valued truth table has psychological reality for both types of conditional – true, false, or void for indicative conditionals and win, lose or void for conditiona...

  13. Modeling conditional correlations of asset returns

    DEFF Research Database (Denmark)

    Silvennoinen, Annastiina; Teräsvirta, Timo

    2015-01-01

    In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM-test is d......In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM......-test is derived to test the constancy of correlations and LM- and Wald tests to test the hypothesis of partially constant correlations. Analytical expressions for the test statistics and the required derivatives are provided to make computations feasible. An empirical example based on daily return series of five...

  14. Cryotherapy, Sensation, and Isometric-Force Variability

    Science.gov (United States)

    Denegar, Craig R.; Buckley, William E.; Newell, Karl M.

    2003-01-01

    Objective: To determine the changes in sensation of pressure, 2-point discrimination, and submaximal isometric-force production variability due to cryotherapy. Design and Setting: Sensation was assessed using a 2 × 2 × 2 × 3 repeated-measures factorial design, with treatment (ice immersion or control), limb (right or left), digit (finger or thumb), and sensation test time (baseline, posttreatment, or postisometric-force trials) as independent variables. Dependent variables were changes in sensation of pressure and 2-point discrimination. Isometric-force variability was tested with a 2 × 2 × 3 repeated-measures factorial design. Treatment condition (ice immersion or control), limb (right or left), and percentage (10, 25, or 40) of maximal voluntary isometric contraction (MVIC) were the independent variables. The dependent variables were the precision or variability (the standard deviation of mean isometric force) and the accuracy or targeting error (the root mean square error) of the isometric force for each percentage of MVIC. Subjects: Fifteen volunteer college students (8 men, 7 women; age = 22 ± 3 years; mass = 72 ± 21.9 kg; height = 183.4 ± 11.6 cm). Measurements: We measured sensation in the distal palmar aspect of the index finger and thumb. Sensation of pressure and 2-point discrimination were measured before treatment (baseline), after treatment (15 minutes of ice immersion or control), and at the completion of isometric testing (final). Variability (standard deviation of mean isometric force) of the submaximal isometric finger forces was measured by having the subjects exert a pinching force with the thumb and index finger for 30 seconds. Subjects performed the pinching task at the 3 submaximal levels of MVIC (10%, 25%, and 40%), with the order of trials assigned randomly. The subjects were given a target representing the submaximal percentage of MVIC and visual feedback of the force produced as they pinched the testing device. The force exerted

  15. On the explaining-away phenomenon in multivariate latent variable models.

    Science.gov (United States)

    van Rijn, Peter; Rijmen, Frank

    2015-02-01

    Many probabilistic models for psychological and educational measurements contain latent variables. Well-known examples are factor analysis, item response theory, and latent class model families. We discuss what is referred to as the 'explaining-away' phenomenon in the context of such latent variable models. This phenomenon can occur when multiple latent variables are related to the same observed variable, and can elicit seemingly counterintuitive conditional dependencies between latent variables given observed variables. We illustrate the implications of explaining away for a number of well-known latent variable models by using both theoretical and real data examples. © 2014 The British Psychological Society.

  16. Analysis of suspension with variable stiffness and variable damping force for automotive applications

    Directory of Open Access Journals (Sweden)

    Lalitkumar Maikulal Jugulkar

    2016-05-01

    Full Text Available Passive shock absorbers are designed for standard load condition. These give better vibration isolation performance only for the standard load condition. However, if the sprung mass is lesser than the standard mass, comfort and road holding ability is affected. It is demonstrated that sprung mass acceleration increases by 50%, when the vehicle mass varies by 100 kg. In order to obtain consistent damping performance from the shock absorber, it is essential to vary its stiffness and damping properties. In this article, a variable stiffness system is presented, which comprises of two helical springs and a variable fluid damper. Fluid damper intensity is changed in four discrete levels to achieve variable stiffness of the prototype. Numerical simulations have been performed with MATLAB Simscape and Simulink which have been with experimentation on a prototype. Furthermore, the numerical model of the prototype is used in design of real size shock absorber with variable stiffness and damping. Numerical simulation results on the real size model indicate that the peak acceleration will improve by 15% in comparison to the conventional passive solution, without significant deterioration of road holding ability. Arrangement of sensors and actuators for incorporating the system in a vehicle suspension has also been discussed.

  17. Natural Variability of Mexican Forest Fires

    Science.gov (United States)

    Velasco-Herrera, Graciela; Velasco Herrera, Victor Manuel; Kemper-Valverdea, N.

    The purpose of this paper was 1) to present a new algorithm for analyzing the forest fires, 2) to discuss the present understanding of the natural variability at different scales with special emphasis on Mexico conditions since 1972, 3) to analyze the internal and external factors affecting forest fires for example ENSO and Total Solar Irradiance, and 4) to discuss the implications of this knowledge, on research and on restoration and management methods, which purpose is to enhance forest biodiversity conservation. 5) We present an estimate of the Mexican forest fires for the next decade. These results may be useful to minimize human and economic losses.

  18. Xeroderma Pigmentosum: Variable Expressions among Three Siblings

    Directory of Open Access Journals (Sweden)

    M Srinivasa Raju

    2010-01-01

    Full Text Available Xeroderma pigmentosum is a rare disorder transmitted in an autosomal recessive manner. It is characterized by photosensitivity, pigmentary changes, premature skin aging, and malignant tumor development. The frequency of this disorder is approximately 1 case per 250.000 population. Two important causes of mortality are metastatic malignant melanoma and squamous cell carcinoma. Here xeroderma pigmentosum in three siblings presenting with variable expressions is reported. The seventy of the condition was more in one of the more sun exposed sibling and had more signs of malignant lesions. Intraoral pigmentation was also present in all the three siblings.

  19. Imaging Variable Stars with HST

    Science.gov (United States)

    Karovska, M.

    2012-06-01

    (Abstract only) The Hubble Space Telescope (HST) observations of astronomical sources, ranging from objects in our solar system to objects in the early Universe, have revolutionized our knowledge of the Universe its origins and contents. I highlight results from HST observations of variable stars obtained during the past twenty or so years. Multiwavelength observations of numerous variable stars and stellar systems were obtained using the superb HST imaging capabilities and its unprecedented angular resolution, especially in the UV and optical. The HST provided the first detailed images probing the structure of variable stars including their atmospheres and circumstellar environments. AAVSO observations and light curves have been critical for scheduling of many of these observations and provided important information and context for understanding of the imaging results of many variable sources. I describe the scientific results from the imaging observations of variable stars including AGBs, Miras, Cepheids, semiregular variables (including supergiants and giants), YSOs and interacting stellar systems with a variable stellar components. These results have led to an unprecedented understanding of the spatial and temporal characteristics of these objects and their place in the stellar evolutionary chains, and in the larger context of the dynamic evolving Universe.

  20. Low-Frequency Temporal Variability in Mira and Semiregular Variables

    Science.gov (United States)

    Templeton, Matthew R.; Karovska, M.; Waagen, E. O.

    2012-01-01

    We investigate low-frequency variability in a large sample of Mira and semiregular variables with long-term visual light curves from the AAVSO International Database. Our aim is to determine whether we can detect and measure long-timescale variable phenomena in these stars, for example photometric variations that might be associated with supergranular convection. We analyzed the long-term light curves of 522 variable stars of the Mira and SRa, b, c, and d classes. We calculated their low-frequency time-series spectra to characterize rednoise with the power density spectrum index, and then correlate this index with other observable characteristics such as spectral type and primary pulsation period. In our initial analysis of the sample, we see that the semiregular variables have a much broader range of spectral index than the Mira types, with the SRb subtype having the broadest range. Among Mira variables we see that the M- and S-type Miras have similarly wide ranges of index, while the C-types have the narrowest with generally shallower slopes. There is also a trend of steeper slope with larger amplitude, but at a given amplitude, a wide range of slopes are seen. The ultimate goal of the project is to identify stars with strong intrinsic red noise components as possible targets for resolved surface imaging with interferometry.