WorldWideScience

Sample records for understanding vertical mixing

  1. LIDAR vertical profiles over the Oil Sands Region: an important tool in understanding atmospheric particulate matter transport, mixing and transformation

    Science.gov (United States)

    Strawbridge, K. B.

    2013-12-01

    LIDAR technology is an excellent tool to probe the complex vertical structure of the atmosphere at high spatial and temporal resolution. This provides the critical vertical context for the interpretation of ground-based chemistry measurements, airborne measurements and model verification and validation. In recent years, Environment Canada has designed an autonomous aerosol LIDAR system that can be deployed to remote areas such as the oil sands. Currently two autonomous LIDAR systems are making measurements in the oil sands region, one since December, 2012 and the other since July, 2013. The LIDAR transmitter emits two wavelengths (1064nm and 532nm) and the detector assembly collects four channels (1064nm backscatter, 532nm backscatter and 532nm depolarization, 607 nm nitrogen channel). Aerosol profiles from near ground to 20 km are collected every 10-60 s providing sufficient resolution to probe atmospheric dynamics, mixing and transport. The depolarization channel provides key information in identifying and discriminating the various aerosol layers aloft such as dust, forest fire plumes, industrial plume sources or ice crystals. The vertical resolution of the LIDAR can determine whether industrial plumes remain aloft or mix down to the surface and also provide estimates as to the concentration of the particulate at various altitudes. It operates 24 hours a day, seven days a week except during precipitation events. The system is operated remotely and the data are updated every hour to a website to allow near real-time capability. An intensive measurement campaign will be carried out in August and September of 2013 and will provide coincident airborne and ground-based measurements for the two LIDAR systems. The first results from this field study will be presented as well as some statistics on the frequency and evolution of plume events that were detected by the LIDARs.

  2. Aiding Vertical Guidance Understanding

    Science.gov (United States)

    Feary, Michael; McCrobie, Daniel; Alkin, Martin; Sherry, Lance; Polson, Peter; Palmer, Everett; McQuinn, Noreen

    1998-01-01

    A two-part study was conducted to evaluate modern flight deck automation and interfaces. In the first part, a survey was performed to validate the existence of automation surprises with current pilots. Results indicated that pilots were often surprised by the behavior of the automation. There were several surprises that were reported more frequently than others. An experimental study was then performed to evaluate (1) the reduction of automation surprises through training specifically for the vertical guidance logic, and (2) a new display that describes the flight guidance in terms of aircraft behaviors instead of control modes. The study was performed in a simulator that was used to run a complete flight with actual airline pilots. Three groups were used to evaluate the guidance display and training. In the training, condition, participants went through a training program for vertical guidance before flying the simulation. In the display condition, participants ran through the same training program and then flew the experimental scenario with the new Guidance-Flight Mode Annunciator (G-FMA). Results showed improved pilot performance when given training specifically for the vertical guidance logic and greater improvements when given the training and the new G-FMA. Using actual behavior of the avionics to design pilot training and FMA is feasible, and when the automated vertical guidance mode of the Flight Management System is engaged, the display of the guidance mode and targets yields improved pilot performance.

  3. Characterization of vertical mixing in oscillatory vegetated flows

    Science.gov (United States)

    Abdolahpour, M.; Ghisalberti, M.; Lavery, P.; McMahon, K.

    2016-02-01

    Seagrass meadows are primary producers that provide important ecosystem services, such as improved water quality, sediment stabilisation and trapping and recycling of nutrients. Most of these ecological services are strongly influenced by the vertical exchange of water across the canopy-water interface. That is, vertical mixing is the main hydrodynamic process governing the large-scale ecological and environmental impact of seagrass meadows. The majority of studies into mixing in vegetated flows have focused on steady flow environments whereas many coastal canopies are subjected to oscillatory flows driven by surface waves. It is known that the rate of mass transfer will vary greatly between unidirectional and oscillatory flows, necessitating a specific investigation of mixing in oscillatory canopy flows. In this study, we conducted an extensive laboratory investigation to characterise the rate of vertical mixing through a vertical turbulent diffusivity (Dt,z). This has been done through gauging the evolution of vertical profiles of concentration (C) of a dye sheet injected into a wave-canopy flow. Instantaneous measurement of the variance of the vertical concentration distribution ( allowed the estimation of a vertical turbulent diffusivity (). Two types of model canopies, rigid and flexible, with identical heights and frontal areas, were subjected to a wide and realistic range of wave height and period. The results showed two important mechanisms that dominate vertical mixing under different conditions: a shear layer that forms at the top of the canopy and wake turbulence generated by the stems. By allowing a coupled contribution of wake and shear layer mixing, we present a relationship that can be used to predict the rate of vertical mixing in coastal canopies. The results further showed that the rate of vertical mixing within flexible vegetation was always lower than the corresponding rigid canopy, confirming the impact of plant flexibility on canopy

  4. Topographic enhancement of vertical turbulent mixing in the Southern Ocean

    Science.gov (United States)

    Mashayek, A.; Ferrari, R.; Merrifield, S.; Ledwell, J. R.; St Laurent, L.; Garabato, A. Naveira

    2017-03-01

    It is an open question whether turbulent mixing across density surfaces is sufficiently large to play a dominant role in closing the deep branch of the ocean meridional overturning circulation. The diapycnal and isopycnal mixing experiment in the Southern Ocean found the turbulent diffusivity inferred from the vertical spreading of a tracer to be an order of magnitude larger than that inferred from the microstructure profiles at the mean tracer depth of 1,500 m in the Drake Passage. Using a high-resolution ocean model, it is shown that the fast vertical spreading of tracer occurs when it comes in contact with mixing hotspots over rough topography. The sparsity of such hotspots is made up for by enhanced tracer residence time in their vicinity due to diffusion toward weak bottom flows. The increased tracer residence time may explain the large vertical fluxes of heat and salt required to close the abyssal circulation.

  5. Understanding neutrino masses and mixings

    Indian Academy of Sciences (India)

    atmospheric neutrino observations, where there is a deficit of observed neutrinos compared to theoretical expectations. ... and reactor neutrinos as in the Kamland experiment have also shown deficits in their flux compared to ... In this brief overview, I wish to draw attention to some of the theoretical ideas for understanding ...

  6. Contribution of extreme meteorological forcing to vertical mixing in a small, shallow subtropical lake

    Directory of Open Access Journals (Sweden)

    Nobuaki Kimura

    2016-10-01

    Full Text Available Studying mixing processes in a stratified lake is important for understanding the biological, chemical and physical processes occurring there. Statistical analyses were performed of data from a small, shallow, stratified lake in a subtropical alpine region (Yuan-Yang Lake in Taiwan to determine the predominant physical factors in heavy-rainfall-induced mixing. This study focused on both vertical mixing in the entire water column and surface-layer mixing extending to the upper thermocline. The effects of meteorological driving forces, such as wind, heating/cooling and inflow on vertical mixing and surface layer mixing, were evaluated using the relationships between each driving force and the change in thermal stability between the pre-mixing and mixing periods. For surface layer mixing, a comparison between penetrative convection related to heating/cooling and wind-related friction velocity was conducted for each heavy rainfall event. A heat content parameter measuring thermal potential energy was introduced to further investigate inflow effects (e.g. effects of changes in discharge volume and temperature on vertical mixing during heavy rainfall events. Results show that wind input affected vertical mixing more significantly than did other meteorological forcing factors during storm-dominant events. Indeed, wind energy input in the surface layer was more pronounced than was energy of heating/cooling for surface layer mixing. Furthermore, inflow effect was shown to be crucial during large scale and extreme weather events (i.e. lower air pressure events in the vertical mixing process. Forcing by heating/cooling likely contributes less to mixing because it is likely less dynamic than the wind and inflow inputs with respect to internal response of the lake. In addition, a principal component analysis (PCA modified by partial correlation was performed to verify the results quantitatively. The first and second components, which accounted for more than

  7. Mixed multilayered vertical heterostructures utilizing strained monolayer WS2

    Science.gov (United States)

    Sheng, Yuewen; Xu, Wenshuo; Wang, Xiaochen; He, Zhengyu; Rong, Youmin; Warner, Jamie H.

    2016-01-01

    Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer of WS2, with Boron Nitride and Graphene. The 2D materials are all grown by CVD, enabling large area vertical heterostructures to be formed. WS2 monolayers grown by CVD directly on Si substrates with SiO2 surface are easily washed off by water and this makes aqueous based transfer methods challenging for creating vertical stacks on the growth substrate. 2D hexagonal Boron Nitride films are used to provide an insulating layer that limits interactions with a top graphene layer and preserve the strong photoluminescence from the WS2. This transfer method is suitable for layer by layer control of 2D material vertical stacks and is shown to be possible for all CVD grown samples, which opens up pathways for the rapid large scale fabrication of vertical heterostructure systems with atomic thickness depth control and large area coverage.Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer of WS2, with Boron Nitride and Graphene. The 2D materials are all grown by CVD, enabling large area vertical heterostructures to be formed. WS2 monolayers grown by

  8. VERTICAL CONTROL OF OVERBITE IN MIXED DENTITION BY TRAINER SYSTEM

    Directory of Open Access Journals (Sweden)

    Miroslava Dinkova

    2014-11-01

    Full Text Available Purpose. The purpose of this study is to follow-up the biometrical and skeletal vertical changes in patients with deep overbite in mixed dentition after a functional orthodontic treatment with Trainer System™ is conducted. Material and Methods. 32 patients (20 girls and 12 boys with deep overbite in mixed dentition were followed-up. An orthodontic treatment with Trainer System™, including Trainer for kids (T4K-blue, T4K-red and Myobrace was conducted. The recommended time for wearing the appliances was 8–12 hours, mostly at the night and 1–2 hours total time during the day. All the patients were photo-documented. Impressions, panoramic radiographs and lateral cephalograms were taken before the beginning of the treatment and at the end of every single step in relation with every change of appliances. Comparative biometrical and cephalometric analyses were made. The data was statistically processed. Results. The comparative biometrical analyses showed reduction of overbite with 2.5–3.5 mm after the end of the orthodontic treatment. 62% of cases showed relapse from 0.5 to 1mm. After the end of the orthodontic treatment an inclination of upper and lower incisors and changes with M/SN, М/F, ANB, SNA, SNB values were established. Conclusions. If untreated during the growing period, deep overbite leads to serious functional disorders, pathologic abrasion and myo-articular problems. Myofunctional Trainer System™ is successfully applied in the management of deep overbite in growing kids with early mixed dentition. The design of appliances helps the right positioning of tongue and jaws, removes bad habits, harmonizes tooth arches, corrects the vertical problems.

  9. Zooplankton structure and vertical migration: Using acoustics and biomass to compare stratified and mixed fjord systems

    Science.gov (United States)

    Díaz-Astudillo, Macarena; Cáceres, Mario A.; Landaeta, Mauricio F.

    2017-09-01

    The patterns of abundance, composition, biomass and vertical migration of zooplankton in short-time scales (ADCP device mounted on the hull of a ship were used to obtain vertical profiles of current velocity data and intensity of the backscattered acoustic signal, which was used to study the migratory strategies and to relate the echo intensity with zooplankton biomass. Repeated vertical profiles of temperature, salinity and density were obtained with a CTD instrument to describe the density patterns during both experiments. Zooplankton were sampled every 3 h using a Bongo net to determine abundance, composition and biomass. Migrations were diel in the stratified station, semi-diel in the mixed station, and controlled by light in both locations, with large and significant differences in zooplankton abundance and biomass between day and night samples. No migration pattern associated with the effect of tides was found. The depth of maximum backscatter strength showed differences of approximately 30 m between stations and was deeper in the mixed station. The relation between mean volume backscattering strength (dB) computed from echo intensity and log10 of total dry weight (mg m-3) of zooplankton biomass was moderate but significant in both locations. Biomass estimated from biological samples was higher in the mixed station and determined by euphausiids. Copepods were the most abundant group in both stations. Acoustic methods were a useful technique to understand the detailed patterns of migratory strategies of zooplankton and to help estimate zooplankton biomass and abundance in the inner waters of southern Chile.

  10. Effect of interannual variation in winter vertical mixing on CH4 dynamics in a subtropical reservoir

    Science.gov (United States)

    Itoh, Masayuki; Kobayashi, Yuki; Chen, Tzong-Yueh; Tokida, Takeshi; Fukui, Manabu; Kojima, Hisaya; Miki, Takeshi; Tayasu, Ichiro; Shiah, Fuh-Kwo; Okuda, Noboru

    2015-07-01

    Although freshwaters are considered to be substantial natural sources of atmospheric methane (CH4), in situ processes of CH4 production and consumption in freshwater ecosystems are poorly understood, especially in subtropical areas, leading to uncertainties in the estimation of global CH4 emissions. To improve our understanding of physical and biogeochemical factors affecting CH4 dynamics in subtropical lakes, we examined vertical and seasonal profiles of dissolved CH4 and its carbon isotope ratio (δ13C) and conducted incubation experiments to assess CH4 production and oxidation in the deep subtropical Fei-Tsui Reservoir (FTR; Taiwan). The mixing pattern of the FTR is essentially monomixis, but the intensity of winter vertical mixing changes with climatic conditions. In years with incomplete vertical mixing (does not reach the bottom) and subsequent strong thermal stratification resulting in profundal hypoxia, we observed increases in sedimentary CH4 production and thus profundal CH4 storage with the development of reducing conditions. In contrast, in years with strong winter vertical mixing to the bottom of the reservoir, CH4 production was suppressed under NO3--rich conditions, during which denitrifiers have the competitive advantage over methanogens. Diffusive emission from profundal CH4 storage appeared to be negligible due to the efficiency of CH4 oxidation during ascent through methane-oxidizing bacteria (MOB) activity. Most of the profundal CH4 was rapidly oxidized by MOB in both oxic and anoxic layers, as characterized by its carbon isotope signature. In contrast, aerobic CH4 production in the subsurface layer, which may be enhanced under high temperatures in summer, may account for a large portion of atmospheric CH4 emissions from this reservoir. Our CH4 profiling results provide valuable information for future studies predicting CH4 emissions from subtropical lakes with the progress of global warming.

  11. Impact of enhanced vertical mixing on marine biogeochemistry: lessons for geo-engineering and natural variability

    Directory of Open Access Journals (Sweden)

    S. Dutreuil

    2009-05-01

    Full Text Available Artificially enhanced vertical mixing has been suggested as a means by which to fertilize the biological pump with subsurface nutrients and thus increase the oceanic CO2 sink. We use an ocean general circulation and biogeochemistry model (OGCBM to examine the impact of artificially enhanced vertical mixing on biological productivity and atmospheric CO2, as well as the climatically significant gases nitrous oxide (N2O and dimethyl sulphide (DMS during simulations between 2000 and 2020. Overall, we find a large increase in the amount of organic carbon exported from surface waters, but an overall increase in atmospheric CO2 concentrations by 2020. We quantified the individual effect of changes in dissolved inorganic carbon (DIC, alkalinity and biological production on the change in pCO2 at characteristic sites and found the increased vertical supply of carbon rich subsurface water to be primarily responsible for the enhanced CO2 outgassing, although increased alkalinity and, to a lesser degree, biological production can compensate in some regions. While ocean-atmosphere fluxes of DMS do increase slightly, which might reduce radiative forcing, the oceanic N2O source also expands. Our study has implications for understanding how natural variability in vertical mixing in different ocean regions (such as that observed recently in the Southern Ocean can impact the ocean CO2 sink via changes in DIC, alkalinity and carbon export.

  12. Understanding and Improving Ocean Mixing Parameterizations for modeling Climate Change

    Science.gov (United States)

    Howard, A. M.; Fells, J.; Clarke, J.; Cheng, Y.; Canuto, V.; Dubovikov, M. S.

    2017-12-01

    Climate is vital. Earth is only habitable due to the atmosphere&oceans' distribution of energy. Our Greenhouse Gas emissions shift overall the balance between absorbed and emitted radiation causing Global Warming. How much of these emissions are stored in the ocean vs. entering the atmosphere to cause warming and how the extra heat is distributed depends on atmosphere&ocean dynamics, which we must understand to know risks of both progressive Climate Change and Climate Variability which affect us all in many ways including extreme weather, floods, droughts, sea-level rise and ecosystem disruption. Citizens must be informed to make decisions such as "business as usual" vs. mitigating emissions to avert catastrophe. Simulations of Climate Change provide needed knowledge but in turn need reliable parameterizations of key physical processes, including ocean mixing, which greatly impacts transport&storage of heat and dissolved CO2. The turbulence group at NASA-GISS seeks to use physical theory to improve parameterizations of ocean mixing, including smallscale convective, shear driven, double diffusive, internal wave and tidal driven vertical mixing, as well as mixing by submesoscale eddies, and lateral mixing along isopycnals by mesoscale eddies. Medgar Evers undergraduates aid NASA research while learning climate science and developing computer&math skills. We write our own programs in MATLAB and FORTRAN to visualize and process output of ocean simulations including producing statistics to help judge impacts of different parameterizations on fidelity in reproducing realistic temperatures&salinities, diffusivities and turbulent power. The results can help upgrade the parameterizations. Students are introduced to complex system modeling and gain deeper appreciation of climate science and programming skills, while furthering climate science. We are incorporating climate projects into the Medgar Evers college curriculum. The PI is both a member of the turbulence group at

  13. Role of vertical and horizontal mixing in the tape recorder signal near the tropical tropopause

    Science.gov (United States)

    Glanville, Anne A.; Birner, Thomas

    2017-03-01

    Nearly all air enters the stratosphere through the tropical tropopause layer (TTL). The TTL therefore exerts a control on stratospheric chemistry and climate. The hemispheric meridional overturning (Brewer-Dobson) circulation spreads this TTL influence upward and poleward. Stratospheric water vapor concentrations are set near the tropical tropopause and are nearly conserved in the lowermost stratosphere. The resulting upward propagating tracer transport signal of seasonally varying entry concentrations is known as the tape recorder signal. Here, we study the roles of vertical and horizontal mixing in shaping the tape recorder signal in the tropical lowermost stratosphere, focusing on the 80 hPa level. We analyze the tape recorder signal using data from satellite observations, a reanalysis, and a chemistry-climate model (CCM). By modifying past methods, we are able to capture the seasonal cycle of effective vertical transport velocity in the tropical lowermost stratosphere. Effective vertical transport velocities are found to be multiple times stronger than residual vertical velocities for the reanalysis and the CCM. We also study the tape recorder signal in an idealized 1-D transport model. By performing a parameter sweep, we test a range of different strengths of transport contributions by vertical advection, vertical mixing, and horizontal mixing. By introducing seasonality into the transport strengths, we find that the most successful simulation of the observed tape recorder signal requires vertical mixing at 80 hPa that is multiple times stronger compared to previous estimates in the literature. Vertical mixing is especially important during boreal summer when vertical advection is weak. Simulating the reanalysis tape recorder requires excessive amounts of vertical mixing compared to observations but also to the CCM, which hints at the role of spurious dispersion due to data assimilation. Contrasting the results between pressure and isentropic coordinates

  14. Experimental studies of vertical mixing patterns in open channel flow generated by two delta wings side-by-side

    Science.gov (United States)

    Vaughan, Garrett

    Open channel raceway bioreactors are a low-cost system used to grow algae for biofuel production. Microalgae have many promises when it comes to renewable energy applications, but many economic hurdles must be overcome to achieve an economic fuel source that is competitive with petroleum-based fuels. One way to make algae more competitive is to improve vertical mixing in algae raceway bioreactors. Previous studies show that mixing may be increased by the addition of mechanisms such as airfoils. The circulation created helps move the algae from the bottom to top surface for necessary photosynthetic exchange. This improvement in light utilization allowed a certain study to achieve 2.2-2.4 times the amount of biomass relative to bioreactors without airfoils. This idea of increasing mixing in open channel raceways has been the focus of the Utah State University (USU) raceway hydraulics group. Computational Fluid Dynamics (CFD), Acoustic Doppler Velocimetry (ADV), and Particle Image Velocimetry (PIV) are all methods used at USU to computationally and experimentally quantify mixing in an open channel raceway. They have also been used to observe the effects of using delta wings (DW) in increasing vertical mixing in the raceway. These efforts showed great potential in the DW in increasing vertical mixing in the open channel bioreactor. However, this research begged the question, does the DW help increase algae growth? Three algae growth experiments comparing growth in a raceway with and without DW were completed. These experiments were successful, yielding an average 27.1% increase in the biomass. The DW appears to be a promising method of increasing algae biomass production. The next important step was to quantify vertical mixing and understand flow patterns due to two DWs side-by-side. Raceway channels are wider as they increase in size; and arrays of DWs will need to be installed to achieve quality mixing throughout the bioreactor. Quality mixing was attained for

  15. Gold Mine or Minefield: Understanding Russian Law on Vertical Restraints

    Directory of Open Access Journals (Sweden)

    Valentina Rucker

    2015-02-01

    Full Text Available While the Russian Federation represents a significant opportunity for growth, that opportunity is coupled with serious risks. As it relates to managing product distribution, Russian vertical restraint law remains significantly more restrictive than that of the U.S. and, since unless a company is fully integrated, it must manage its distribution system by way of vertical agreements, presents a large problem for businesses seeking to conduct business in Russia. While Russia has made significant steps in the right direction, the lack of consistent application of economic analysis to evaluation of vertical restraints leaves companies exposed. Further, the sometimes inconsistent application of the laws also makes it hard to predict how any particular vertical agreement would be evaluated. Neither American nor Russian antitrust laws establish a list of possible vertical restraints. Thus, there is no exhaustive guidance regarding how these restraints should be treated. U.S. antitrust laws, however, generally place all vertical restraints into one of two categories, intrabrand restraints and interbrand restraints. Intrabrand restraints are those that restrain the downstream firm’s freedom with regard to the resale of the product at issue (distribution restrictions. Interbrand restraints are those that restrict a downstream or upstream firm’s freedom to deal with competitors of the firm imposing the restraint (interbrand restrictions. It should be noted that Russian law does not make this distinction.

  16. Gold Mine or Minefield: Understanding Russian Law on Vertical Restraints

    Directory of Open Access Journals (Sweden)

    Valentina Rucker

    2014-01-01

    Full Text Available While the Russian Federation represents a significant opportunity for growth, that opportunity is coupled with serious risks. As it relates to managing product distribution, Russian vertical restraint law remains significantly more restrictive than that of the U.S. and, since unless a company is fully integrated, it must manage its distribution system by way of vertical agreements, presents a large problem for businesses seeking to conduct business in Russia. While Russia has made significant steps in the right direction, the lack of consistent application of economic analysis to evaluation of vertical restraints leaves companies exposed. Further, the sometimes inconsistent application of the laws also makes it hard to predict how any particular vertical agreement would be evaluated. Neither American nor Russian antitrust laws establish a list of possible vertical restraints. Thus, there is no exhaustive guidance regarding how these restraints should be treated. U.S. antitrust laws, however, generally place all vertical restraints into one of two categories, intrabrand restraints and interbrand restraints. Intrabrand restraints are those that restrain the downstream firm’s freedom with regard to the resale of the product at issue (distribution restrictions. Interbrand restraints are those that restrict a downstream or upstream firm’s freedom to deal with competitors of the firm imposing the restraint (interbrand restrictions. It should be noted that Russian law does not make this distinction.

  17. Assessing ocean vertical mixing schemes for the study of climate change

    Science.gov (United States)

    Howard, A. M.; Lindo, F.; Fells, J.; Tulsee, V.; Cheng, Y.; Canuto, V.

    2014-12-01

    Climate change is a burning issue of our time. It is critical to know the consequences of choosing "business as usual" vs. mitigating our emissions for impacts e.g. ecosystem disruption, sea-level rise, floods and droughts. To make predictions we must model realistically each component of the climate system. The ocean must be modeled carefully as it plays a critical role, including transporting heat and storing heat and dissolved carbon dioxide. Modeling the ocean realistically in turn requires physically based parameterizations of key processes in it that cannot be explicitly represented in a global climate model. One such process is vertical mixing. The turbulence group at NASA-GISS has developed a comprehensive new vertical mixing scheme (GISSVM) based on turbulence theory, including surface convection and wind shear, interior waves and double-diffusion, and bottom tides. The GISSVM is tested in stand-alone ocean simulations before being used in coupled climate models. It is also being upgraded to more faithfully represent the physical processes. To help assess mixing schemes, students use data from NASA-GISS to create visualizations and calculate statistics including mean bias and rms differences and correlations of fields. These are created and programmed with MATLAB. Results with the commonly used KPP mixing scheme and the present GISSVM and candidate improved variants of GISSVM will be compared between stand-alone ocean models and coupled models and observations. This project introduces students to modeling of a complex system, an important theme in contemporary science and helps them gain a better appreciation of climate science and a new perspective on it. They also gain familiarity with MATLAB, a widely used tool, and develop skills in writing and understanding programs. Moreover they contribute to the advancement of science by providing information that will help guide the improvement of the GISSVM and hence of ocean and climate models and ultimately our

  18. Vertical Subsurface Flow Mixing and Horizontal Anisotropy in Coarse Fluvial Aquifers: Structural Aspects

    Science.gov (United States)

    Huggenberger, P.; Huber, E.

    2014-12-01

    Detailed descriptions of the subsurface heterogeneities in coarse fluvial aquifer gravel often lack in concepts to distinguish between the essence and the noise of a permeability structure and the ability to extrapolate site specific hydraulic information at the tens to several hundred meters scale. At this scale the heterogeneity strongly influences the anisotropies of the flow field and the mixing processes in groundwater. However, in many hydrogeological models the complexity of natural systems is oversimplified. Understanding the link between the dynamics of the surface processes of braided-river systems and the resulting subsurface sedimentary structures is the key to characterizing the complexity of horizontal and vertical mixing processes in groundwater. From the different depositional elements of coarse braided-river systems, the largest permeability contrasts can be observed in the scour-fills. Other elements (e.g. different types of gravel sheets) show much smaller variabilities and could be considered as a kind of matrix. Field experiments on the river Tagliamento (Northeast Italy) based on morphological observation and ground-penetrating radar (GPR) surveys, as well as outcrop analyses of gravel pit exposures (Switzerland) allowed us to define the shape, sizes, spatial distribution and preservation potential of scour-fills. In vertical sections (e.g. 2D GPR data, vertical outcrop), the spatial density of remnant erosional bounding surfaces of scours is an indicator for the dynamics of the braided-river system (lateral mobility of the active floodplain, rate of sediment net deposition and spatial distribution of the confluence scours). In case of combined low aggradation rate and low lateral mobility the deposits may be dominated by a complex overprinting of scour-fills. The delineation of the erosional bounding surfaces, that are coherent over the survey area, is based on the identification of angular discontinuities of the reflectors. Fence diagrams

  19. Deep circulation driven by strong vertical mixing in the Timor Basin

    Science.gov (United States)

    Cuypers, Yannis; Pous, Stephane; Sprintall, Janet; Atmadipoera, Agus; Madec, Gurvan; Molcard, Robert

    2017-02-01

    The importance of deep mixing in driving the deep part of the overturning circulation has been a long debated question at the global scale. Our observations provide an illustration of this process at the Timor Basin scale of ˜1000 km. Long-term averaged moored velocity data at the Timor western sill suggest that a deep circulation is present in the Timor Basin. An inflow transport of ˜0.15 Sv is observed between 1600 m and the bottom at 1890 m. Since the basin is closed on its eastern side below 1250 m depth, a return flow must be generated above 1600 m with a ˜0.15 Sv outflow. The vertical turbulent diffusivity is inferred from a heat and transport balance at the basin scale and from Thorpe scale analysis. Basin averaged vertical diffusivity is as large as 1 × 10-3 m2 s-1. Observations are compared with regional low-resolution numerical simulations, and the deep observed circulation is only recovered when a strong vertical diffusivity resulting from the parameterization of internal tidal mixing is considered. Furthermore, the deep vertical mixing appears to be strongly dependent on the choice of the internal tide mixing parameterization and also on the prescribed value of the mixing efficiency.

  20. Effect of viscous dissipation on mixed convection flow in a vertical ...

    African Journals Online (AJOL)

    papers on mixed convection in a parallel-plate vertical channel are available in the literature. Aung and Worku (1986) ..... in electric circuit analysis. This method constructs ... which implies that the concept of differential transform method is derived from Taylor series expansion, although this method is not able to evaluate the ...

  1. Mixed convective heat transfer from a vertical plate embedded in a ...

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 40; Issue 2. Mixed convective heat transfer from a vertical plate embedded in a saturated non-Darcy porous medium with concentration and melting effect. K Hemalatha Peri K Kameswaran M V D N S Madhavi. Mechanical Sciences Volume 40 Issue 2 April 2015 pp 455-465 ...

  2. Mixed convection flow and heat transfer in a vertical wavy channel ...

    African Journals Online (AJOL)

    Mixed convection flow and heat transfer in a vertical wavy channel filled with porous and fluid layers is studied analytically. The flow in the porous medium is modeled using Darcy-Brinkman equation. The coupled non-linear partial differential equations describing the conservation of mass, momentum and energy are solved ...

  3. Policy Integration and Multi-Level Governance: Dealing with the Vertical Dimension of Policy Mix Designs

    Directory of Open Access Journals (Sweden)

    Michael Howlett

    2017-05-01

    Full Text Available Multifaceted problems such as sustainable development typically involve complex arrangements of institutions and instruments and the subject of how best to design and operate such ‘mixes’, ‘bundles’ or ‘portfolios’ of policy tools is an ongoing issue in this area. One aspect of this question is that some mixes are more difficult to design and operate than others. The paper argues that, ceteris paribus, complex policy-making faces substantial risks of failure when horizontal or vertical dimensions of policy-making are not well integrated. The paper outlines a model of policy mix types which highlights the design problems associated with more complex arrangements and presents two case studies of similarly structured mixes in the areas of marine parks in Australia and coastal zone management in Europe—one a failure and the other a successful case of integration—to illustrate how such mixes can be better designed and managed more effectively.

  4. Mixed convective low flow pressure drop in vertical rod assemblies - I. Predictive model and design correlation

    International Nuclear Information System (INIS)

    Suh, K.Y.; Todreas, N.E.; Robsenow, W.M.

    1987-01-01

    An experimental study has been conducted to confirm and validate the predictive models and correlations for low flow frictional pressure loss in vertical rod bundle geometries under natural circulation conditions. An experimental procedure has been developed to measure low magnitude differential pressures under mixed convection conditions in 19 heated rod bare and wire-wrapped assemblies. The proposed model has been found to successfully predict the effects of wire wrapping, power skew, transition from laminar regime, developing and interacting global and local flow redistributions, and rod number on the mixed convection friction loss characteristics of rod bundles

  5. Vertical Mixed Use Communities: A Solution to Urban Sustainability? Review, Audit and Developer Perspectives

    OpenAIRE

    Simon Huston; Derlie Mateo-Babiano

    2013-01-01

    Purpose - We explore the growth patterns and development trends of vertical mixed use (VMU) developments in a variety of cities. VMUs are defined as structures with two or more revenue producing uses or land use activities on a single site. One view is that sustainable city development requires densification via VMU construction on brown field sites (within the existing inner city footprint). Design/methodology/approach - After a systematic review of the notion of VMU buildings, we conduct a ...

  6. Kinetic mixing between a Higgs boson and a nearly degenerate dark scalar: Oscillations and displaced vertices

    Science.gov (United States)

    Boyanovsky, Daniel; Chen, Junmou

    2017-11-01

    Extensions beyond the standard model allow for a gauge singlet scalar to be kinetically coupled with the Higgs. We consider kinetic mixing between a dark scalar gauge singlet nearly degenerate with the Higgs, focusing on the dynamical aspects of the mixing phenomena. The renormalization program is carried out by obtaining the one-loop effective action which yields an effective non-Hermitian Hamiltonian to study the dynamics of mixing. The scalar Higgs becomes a coherent superposition of the mass eigenstates, thus kinetic mixing leads to oscillations and common decay channels in striking similarity with neutral meson mixing. Near degeneracy yields an enhancement of the kinetic coupling. For small kinetic mixing we find that the mass eigenstates feature different lifetimes which result in a wide separation of time scales of evolution along with important coherence aspects from dark scalar-Higgs interference. The wide separation of scales is manifest as displaced decay vertices which could potentially be a telltale experimental signal of kinetic mixing.

  7. A role of vertical mixing on nutrient supply into the subsurface chlorophyll maximum in the shelf region of the East China Sea

    Science.gov (United States)

    Lee, Keunjong; Matsuno, Takeshi; Endoh, Takahiro; Ishizaka, Joji; Zhu, Yuanli; Takeda, Shigenobu; Sukigara, Chiho

    2017-07-01

    In summer, Changjiang Diluted Water (CDW) expands over the shelf region of the northern East China Sea. Dilution of the low salinity water could be caused by vertical mixing through the halocline. Vertical mixing through the pycnocline can transport not only saline water, but also high nutrient water from deeper layers to the surface euphotic zone. It is therefore very important to quantitatively evaluate the vertical mixing to understand the process of primary production in the CDW region. We conducted extensive measurements in the region during the period 2009-2011. Detailed investigations of the relative relationship between the subsurface chlorophyll maximum (SCM) and the nitracline suggested that there were two patterns relating to the N/P ratio. Comparing the depths of the nitracline and SCM, it was found that the SCM was usually located from 20 to 40 m and just above the nitracline, where the N/P ratio within the nitracline was below 15, whereas it was located from 10 to 30 m and within the nitracline, where the N/P ratio was above 20. The large value of the N/P ratio in the latter case suggests the influence of CDW. Turbulence measurements showed that the vertical flux of nutrients with vertical mixing was large (small) where the N/P ratio was small (large). A comparison with a time series of primary production revealed a consistency with the pattern of snapshot measurements, suggesting that the nutrient supply from the lower layer contributes considerably to the maintenance of SCM.

  8. Error characterization of CO2 vertical mixing in the atmospheric transport model WRF-VPRM

    Directory of Open Access Journals (Sweden)

    U. Karstens

    2012-03-01

    Full Text Available One of the dominant uncertainties in inverse estimates of regional CO2 surface-atmosphere fluxes is related to model errors in vertical transport within the planetary boundary layer (PBL. In this study we present the results from a synthetic experiment using the atmospheric model WRF-VPRM to realistically simulate transport of CO2 for large parts of the European continent at 10 km spatial resolution. To elucidate the impact of vertical mixing error on modeled CO2 mixing ratios we simulated a month during the growing season (August 2006 with different commonly used parameterizations of the PBL (Mellor-Yamada-Janjić (MYJ and Yonsei-University (YSU scheme. To isolate the effect of transport errors we prescribed the same CO2 surface fluxes for both simulations. Differences in simulated CO2 mixing ratios (model bias were on the order of 3 ppm during daytime with larger values at night. We present a simple method to reduce this bias by 70–80% when the true height of the mixed layer is known.

  9. CFD simulation of vertical linear motion mixing in anaerobic digester tanks.

    Science.gov (United States)

    Meroney, Robert N; Sheker, Robert E

    2014-09-01

    Computational fluid dynamics (CFD) was used to simulate the mixing characteristics of a small circular anaerobic digester tank (diameter 6 m) equipped sequentially with 13 different plunger type vertical linear motion mixers and two different type internal draft-tube mixers. Rates of mixing of step injection of tracers were calculated from which active volume (AV) and hydraulic retention time (HRT) could be calculated. Washout characteristics were compared to analytic formulae to estimate any presence of partial mixing, dead volume, short-circuiting, or piston flow. Active volumes were also estimated based on tank regions that exceeded minimum velocity criteria. The mixers were ranked based on an ad hoc criteria related to the ratio of AV to unit power (UP) or AV/UP. The best plunger mixers were found to behave about the same as the conventional draft-tube mixers of similar UP.

  10. Vertical mixing and elements of mesoscale dynamics over North Carolina shelf and contiguous Gulf Stream waters

    Science.gov (United States)

    Lozovatsky, Iossif; Planella-Morato, Jesus; Shearman, Kipp; Wang, Qing; Fernando, Harindra Joseph S.

    2017-06-01

    Results of microstructure measurements conducted in October-November of 2015 as a part of the Coupled Air Sea Processes and Electromagnetic Ducting Research (CASPER) project are discussed. The measurements were taken on the North Carolina shelf and across the Gulf Stream front. On the shelf, the oceanic stratification was influenced by highly variable surface salinity and along-bottom advection. Vertical mixing was mostly governed by variable winds. The vertical eddy diffusivity was estimated using the VMP-based dissipation measurements, and the diffusivity values obtained during calm periods and stormy winds were compared. Parameterization of the diffusivity for various mesoscale dynamical conditions is discussed in terms of shear instabilities and internal wave-generated turbulence based on data obtained in deep waters of the Gulf Stream and on the continental slope.

  11. Heat Transfer in MHD Mixed Convection Flow of a Ferrofluid along a Vertical Channel.

    Directory of Open Access Journals (Sweden)

    Aaiza Gul

    Full Text Available This study investigated heat transfer in magnetohydrodynamic (MHD mixed convection flow of ferrofluid along a vertical channel. The channel with non-uniform wall temperatures was taken in a vertical direction with transverse magnetic field. Water with nanoparticles of magnetite (Fe3O4 was selected as a conventional base fluid. In addition, non-magnetic (Al2O3 aluminium oxide nanoparticles were also used. Comparison between magnetic and magnetite nanoparticles were also conducted. Fluid motion was originated due to buoyancy force together with applied pressure gradient. The problem was modelled in terms of partial differential equations with physical boundary conditions. Analytical solutions were obtained for velocity and temperature. Graphical results were plotted and discussed. It was found that temperature and velocity of ferrofluids depend strongly on viscosity and thermal conductivity together with magnetic field. The results of the present study when compared concurred with published work.

  12. Mixed Convection Heat Transfer on the Outside of a Vertical Cylinder

    International Nuclear Information System (INIS)

    Bhattacharyya, A.

    1965-10-01

    An experimental study was made of turbulent heat transfer from a vertical cylinder placed in a square channel. The flow medium was water flowing upwards. Basic differential equations governing the mixed flow heat transfer phenomena in a vertical annulus are presented. A dimensional analysis is done to find the dimensionless variables affecting the relative magnitude of the effect of buoyancy on forced convection heat transfer. Dimensionless equations correlating the experimental data ana incorporating a buoyancy parameter of the form Gr/Re 2 are presented. Reynolds number range covered is 690 to 129,500 and the Rayleigh num- ber range covered is 10 9 to 4.2 x 10 13 . Effect of different length parameters, like hydraulic diameter and distance of the measuring point from the inlet of the test section, on dimensionless equations are studied

  13. Review of Mixed Convection Flow Regime Map of a Vertical pipe

    International Nuclear Information System (INIS)

    Chae, Myeong-Seon; Chung, Bum-Jin; Kang, Gyeong-Uk

    2015-01-01

    In a vertical pipe, the natural convective force due to buoyancy acts upward only, but forced convective force can be either upward or downward. This determines buoyancy-aided and buoyancy-opposed flows depending on the direction of forced flow with respect to the buoyancy forces. Furthermore, depending on the exchange mechanism, the flow condition is classified into laminar and turbulent. In laminar mixed convection, buoyancy-aided flow presents enhanced heat transfer compared to the pure forced convection and buoyancy-opposed flow shows impaired heat transfer as the flow velocity affected by the buoyancy forces. However, in turbulent mixed convection, buoyancy-aided flow shows an impairment of the heat transfer rate for small buoyancy, and a gradational enhancement for large buoyancy. In this study, the existing flow regime map on mixed convection in a vertical pipe was reviewed through an analysis of literatures. Using the investigated data and heat transfer correlations, the flow regime map was reconstructed independently, and compared with the existing one. This study reviewed the limitations of the classical mixed convection flow regime map. Using the existing data and heat transfer correlations by Martinelli and Boelter and Watzinger and Johnson, the flow regime map was reconstructed independently. The results revealed that the existing map used the data selectively among the experimental and theoretical results, and a detailed description for lines forming mixed convection and transition regime were not given. And the information about uncertainty analysis and the evidentiary data were given insufficiently. The flow regime map and investigator commonly used the diameter as the characteristic length for both Re and Gr in place of the height of the heated wall, though the buoyancy forces are proportional to the third power of the height of heated wall

  14. Northern Arabian Sea Circulation Autonomous Research (NASCar) DRI: A Study of Vertical Mixing Processes in the Northern Arabian Sea

    Science.gov (United States)

    2015-09-30

    energy that might otherwise radiate downward and drive subsurface mixing over a broader range of depths. As examined in Polton et al. (2008), the...duration or fetch- limited. Both monsoonal rains and diurnal shortwave heat fluxes at O(1) kW/m2 play a large role in modulating vertical mixing in the...mixed layer may marginally impact entrainment of the upper layer by trapping gravity wave energy at the interface between the two well-mixed layers

  15. The effect of wind mixing on the vertical distribution of buoyant plastic debris

    Science.gov (United States)

    Kukulka, T.; Proskurowski, G.; Morét-Ferguson, S.; Meyer, D. W.; Law, K. L.

    2012-04-01

    Micro-plastic marine debris is widely distributed in vast regions of the subtropical gyres and has emerged as a major open ocean pollutant. The fate and transport of plastic marine debris is governed by poorly understood geophysical processes, such as ocean mixing within the surface boundary layer. Based on profile observations and a one-dimensional column model, we demonstrate that plastic debris is vertically distributed within the upper water column due to wind-driven mixing. These results suggest that total oceanic plastics concentrations are significantly underestimated by traditional surface measurements, requiring a reinterpretation of existing plastic marine debris data sets. A geophysical approach must be taken in order to properly quantify and manage this form of marine pollution.

  16. Homotopy simulation of axisymmetric laminar mixed convection nanofluid boundary layer flow over a vertical cylinder

    Directory of Open Access Journals (Sweden)

    Freidooni Mehr N.

    2012-01-01

    Full Text Available In this paper, the semi-analytical/numerical technique known as the homotopy analysis method (HAM is employed to derive solutions for the laminar axisymmetric mixed convection boundary-layer nanofluid flow past a vertical cylinder. The similarity solutions are employed to transform the parabolic partial differential conservation equations into system of nonlinear, coupled ordinary differential equations, subject to appropriate boundary conditions. A comparison has been done to verify the obtained results with the purely numerical results of Grosan and Pop (2011 with excellent correlation achieved. The effects of nanoparticle volume fraction, curvature parameter and mixed convection or buoyancy parameter on the dimensionless velocity and temperature distributions, skin friction and wall temperature gradients are illustrated graphically. HAM is found to demonstrate excellent potential for simulating nanofluid dynamics problems. Applications of the study include materials processing and also thermal enhancement of energy systems.

  17. Vertical mixing and coherent anticyclones in the ocean: the role of stratification

    Directory of Open Access Journals (Sweden)

    I. Koszalka

    2010-01-01

    Full Text Available The role played by wind-forced anticyclones in the vertical transport and mixing at the ocean mesoscale is investigated with a primitive-equation numerical model in an idealized configuration. The focus of this work is to determine how the stratification impacts such transport.

    The flows, forced only at the surface by an idealized wind forcing, are predominantly horizontal and, on average, quasigeostrophic. Inside vortex cores and intense filaments, however, the dynamics is strongly ageostrophic.

    Mesoscale anticyclones appear as "islands" of increased penetration of wind energy into the ocean interior and they represent the maxima of available potential energy. The amount of available potential energy is directly correlated with the degree of stratification.

    The wind energy injected at the surface is transferred at depth through the generation and subsequent straining effect of Vortex Rossby Waves (VRWs, and through near-inertial internal oscillations trapped inside anticyclonic vortices. Both these mechanisms are affected by stratification. Stronger transfer but larger confinement close to the surface is found when the stratification is stronger. For weaker stratification, vertical mixing close to the surface is less intense but below about 150 m attains substantially higher values due to an increased contribution of both VRWs, whose time scale is on the order of few days, and of near-inertial motions, with a time scale of few hours.

  18. Understanding the Mixing Phenomena - from Structural Stability to Chaos

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2011-01-01

    Full Text Available Nowadays, computational fluid dynamics (CFD becomes
    more and more mature. In the same time, it becomes more and more difficult to contribute fundamental research to it. Although the software tools in this area are increasing in importance, the way how CFD develops remain unpredictable, and it is part of what makes it an exciting and attractive discipline. The mixing phenomena - and the mixing theory - are using more and more CFD tools. This modern theory issued in the flow kinematics after hundred of years of stability study, has mathematical methods and techniques which are developing a continuous signi¯cant relation between turbulence and chaos. The turbulence is an important feature of dynamic systems with few freedom degrees, the so-called far from equilibrium systems. These are widespread between the models of excitable media. The present paper exhibits some recent results of the turbulent mixing study, based on computational tools of MAPLE11 soft. The data would be statistically analyzed, in order to construct a significant guideline in understanding the transition from stability to
    chaos in these excitable media.

  19. Lateral Mixing Mechanisms in Vertical and Horizontal Interconnected Subchannel Two-Phase Flows

    International Nuclear Information System (INIS)

    Gencay, Sarman; Teyssedou, Alberto; Tye, Peter

    2002-01-01

    A lateral mixing model based on equal volume exchange between two laterally interconnected subchannels is presented. The following mixing mechanisms are taken into account in this model: (a) diversion cross flow, caused by the lateral pressure difference between adjacent subchannels; (b) turbulent void diffusion, which is governed by the lateral void fraction difference between the subchannels; (c) void drift, responsible for the tendency of the vapor phase to drift toward unobstructed regions; and (d) buoyancy drift, which takes into account the effect of gravity in horizontal flows. Experimental two-phase air-water data obtained using two test sections having different geometries and orientations are used to determine the diffusion coefficients required by the mixing model. Under the absence of diversion crossflow, i.e., negligible lateral pressure difference between the subchannels, it is observed that the diffusion coefficient increases with increasing average void fraction in the subchannels. Moreover, for vertical flows turbulent void diffusion seems to be considerably affected by the geometry of the subchannels. For horizontal flows under nonsymmetric inlet void fraction conditions, even though the interconnected subchannels have the same geometry, different turbulent void diffusion and void drift coefficients are required to satisfy the conditions of hydrodynamic equilibrium. In the present study this condition is achieved by introducing a new void drift coefficient expressed as a correction term applied to the turbulent void drift term

  20. Mixed convective magnetohydrodynamic flow in a vertical channel filled with nanofluids

    Directory of Open Access Journals (Sweden)

    S. Das

    2015-06-01

    Full Text Available The fully developed mixed convection flow in a vertical channel filled with nanofluids in the presence of a uniform transverse magnetic field has been studied. Closed form solutions for the fluid temperature, velocity and induced magnetic field are obtained for both the buoyancy-aided and -opposed flows. Three different water-based nanofluids containing copper, aluminium oxide and titanium dioxide are taken into consideration. Effects of the pertinent parameters on the nanofluid temperature, velocity, and induced magnetic field as well as the shear stress and the rate of heat transfer at the channel wall are shown in figures and tables followed by a quantitative discussion. It is found that the magnetic field tends to enhance the nanofluid velocity in the channel. The induced magnetic field vanishes in the cental region of the channel. The critical Rayleigh number at onset of instability of flow is strongly dependent on the volume fraction of nanoparticles and the magnetic field.

  1. Experimental validation data for CFD of steady and transient mixed convection on a vertical flat plate

    Science.gov (United States)

    Lance, Blake W.

    Simulations are becoming increasingly popular in science and engineering. One type of simulation is Computation Fluid Dynamics (CFD) that is used when closed forms solutions are impractical. The field of Verification & Validation emerged from the need to assess simulation accuracy as they often contain approximations and calibrations. Validation involves the comparison of experimental data with simulation outputs and is the focus of this work. Errors in simulation predictions may be assessed in this way. Validation requires highly-detailed data and description to accompany these data, and uncertainties are very important. The purpose of this work is to provide highly complete validation data to assess the accuracy of CFD simulations. This aim is fundamentally different from the typical discovery experiments common in research. The measurement of these physics was not necessarily original but performed with modern, high-fidelity methods. Data were tabulated through an online database for direct use in Reynolds-Averaged Navier-Stokes simulations. Detailed instrumentation and documentation were used to make the data more useful for validation. This work fills the validation data gap for steady and transient mixed convection. The physics in this study included mixed convection on a vertical flat plate. Mixed convection is a condition where both forced and natural convection influence fluid momentum and heat transfer phenomena. Flow was forced over a vertical flat plate in a facility built for validation experiments. Thermal and velocity data were acquired for steady and transient flow conditions. The steady case included both buoyancy-aided and buoyancy-opposed mixed convection while the transient case was for buoyancy-opposed flow. The transient was a ramp-down flow transient, and results were ensemble-averaged for improved statistics. Uncertainty quantification was performed on all results with bias and random sources. An independent method of measuring heat flux was

  2. Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO

    Science.gov (United States)

    Reffray, G.; Bourdalle-Badie, R.; Calone, C.

    2015-01-01

    Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k+l from Blanke and Delecluse, 1993, and two equation models: generic length scale closures from Umlauf and Burchard, 2003) are able to correctly reproduce the classical test of Kato and Phillips (1969) under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a 1-year period (mid-2010 to mid-2011) at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between -2 and 2 °C during the stratified period (June to October). However, the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D) is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (PAPA">http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA). This package is a good starting point for further investigation of vertical processes.

  3. Turbulent mixed convection in vertical and inclined flat channels with aiding flows

    Energy Technology Data Exchange (ETDEWEB)

    Poskas, P.; Vilemas, J.; Adomaitis, J.E.; Bartkus, G.

    1995-09-01

    This paper presents an experimental study of turbulent mixed convection heat transfer for aiding flows in a vertical ({phi}=90{degrees}), inclined ({phi}=60{degrees},30{degrees}), and horizontal ({phi}=0{degrees}) flat channels with symmetrical heating and a ratio of height h to width b of about 1:10 and with length about 4 m (x/2h about 44). The study covered Re from 4x10{sup 3} to 5x10{sup 4} and Gr{sub q} from 5x10{sup 7}to 3x10{sup 10}. For the upper wall, a region of impaired heat transfer was found for all angular positions (from vertical to horizontal) and for bottom wall the augmentation of heat transfer in comparison to forced convection was revealed in the region of {phi}=0{degrees}-60{degrees}. Different characteristic buoyancy parameters were found for regions of impaired and enhanced heat transfer. General relations are suggested to predict the heat transfer for fully-developed-flow conditions and different angular positions.

  4. Effect of Induced Magnetic Field on MHD Mixed Convection Flow in Vertical Microchannel

    Science.gov (United States)

    Jha, B. K.; Aina, B.

    2017-08-01

    The present work presents a theoretical investigation of an MHD mixed convection flow in a vertical microchannel formed by two electrically non-conducting infinite vertical parallel plates. The influence of an induced magnetic field arising due to motion of an electrically conducting fluid is taken into consideration. The governing equations of the motion are a set of simultaneous ordinary differential equations and their exact solutions in dimensionless form have been obtained for the velocity field, the induced magnetic field and the temperature field. The expressions for the induced current density and skin friction have also been obtained. The effects of various non-dimensional parameters such as rarefaction, fluid wall interaction, the Hartmann number and the magnetic Prandtl number on the velocity, the induced magnetic field, the temperature, the induced current density, and skin friction have been presented in a graphical form. It is found that the effect of the Hartmann number and magnetic Prandtl number on the induced current density is found to have a decreasing nature at the central region of the microchannel.

  5. A Study on the Mixed Convection Heat Transfer in a Vertical Cylinder Using Electroplating System

    International Nuclear Information System (INIS)

    Ko, Bong Jin

    2008-02-01

    Hydrogen economy has drawn public attentions as a promising future energy source. Hydrogen is a non-petroleum-based, non-toxic, renewable and clean burning energy source. Hydrogen is the secondary energy, which means that it is produced by consuming the first energy such as coal, gas, petroleum etc. This again means that it is clean so long as it is produced by clean methods. One of the promising production methods of hydrogen is to use the heat from an HTGR(High Temperature Gas-cooled Reactor), a next generation nuclear reactor for a safe and reliable operation as well as for efficient and economic generation of energy. The knowledge of detailed heat transfer phenomena in gaseous phase emerges as an important factor for HTGR, where buoyancy effect plays a significant role. Large and expensive test facilities are to be constructed to assess the detailed mixed convection phenomena. However, using analogy concept, heat transfer system can be transformed to mass transfer system and vice versa. If a simple mass transfer system could be devised, and the experimental solution from that system could be obtained, then this could theoretically lead to a solution for a similar heat transfer system. In this study, a copper electroplating system was selected as the mass transfer system. A copper electroplating system with limiting current technique has a good advantage to simulate heat transfer system as mass transfer coefficient, analogous with heat transfer coefficient, can be directly obtained from the information of the bulk concentration and electric current between electrodes. This study simulated the mixed convective heat transfer phenomena in a vertical cylinder using copper electroplating system. The mixed convection phenomenon is observed when the forced and natural convections are of comparable magnitudes in one system. The mixed convection is classified as laminar and turbulent flows depending on the exchange mechanism and also as buoyancy aided and buoyancy

  6. Experimental Studies of Vertical Mixing Patterns in Open Channel Flow Generated by Two Delta Wings Side-by-Side

    OpenAIRE

    Vaughan, Garrett

    2013-01-01

    Open channel raceway bioreactors are a low-cost system used to grow algae for biofuel production. Microalgae have many promises when it comes to renewable energy applications, but many economic hurdles must be overcome to achieve an economic fuel source that is competitive with petroleum-based fuels. One way to make algae more competitive is to improve vertical mixing in algae raceway bioreactors. Previous studies show that mixing may be increased by the addition of mechanisms such as airf...

  7. Strong influence of deposition and vertical mixing on secondary organic aerosol concentrations in CMAQ and CAMx

    Science.gov (United States)

    Shu, Qian; Koo, Bonyoung; Yarwood, Greg; Henderson, Barron H.

    2017-12-01

    Differences between two air quality modeling systems reveal important uncertainties in model representations of secondary organic aerosol (SOA) fate. Two commonly applied models (CMAQ: Community Multiscale Air Quality; CAMx: Comprehensive Air Quality Model with extensions) predict very different OA concentrations over the eastern U.S., even when using the same source data for emissions and meteorology and the same SOA modeling approach. Both models include an option to output a detailed accounting of how each model process (e.g., chemistry, deposition, etc.) alters the mass of each modeled species, referred to as process analysis. We therefore perform a detailed diagnostic evaluation to quantify simulated tendencies (Gg/hr) of each modeled process affecting both the total model burden (Gg) of semi-volatile organic compounds (SVOC) in the gas (g) and aerosol (a) phases and the vertical structures to identify causes of concentration differences between the two models. Large differences in deposition (CMAQ: 69.2 Gg/d; CAMx: 46.5 Gg/d) contribute to significant OA bias in CMAQ relative to daily averaged ambient concentration measurements. CMAQ's larger deposition results from faster daily average deposition velocities (VD) for both SVOC (g) (VD,cmaq = 2.15 × VD,camx) and aerosols (VD,cmaq = 4.43 × Vd,camx). Higher aerosol deposition velocity would be expected to cause similar biases for inert compounds like elemental carbon (EC), but this was not seen. Daytime low-biases in EC were also simulated in CMAQ as expected but were offset by nighttime high-biases. Nighttime high-biases were a result of overly shallow mixing in CMAQ leading to a higher fraction of EC total atmospheric mass in the first layer (CAMx: 5.1-6.4%; CMAQ: 5.6-6.9%). Because of the opposing daytime and nighttime biases, the apparent daily average bias for EC is reduced. For OA, there are two effects of reduced vertical mixing: SOA and SVOC are concentrated near the surface, but SOA yields are reduced

  8. Stability and disease persistence in an age-structured SIS epidemic model with vertical transmission and proportionate mixing assumption

    International Nuclear Information System (INIS)

    El-Doma, M.

    2001-02-01

    The stability of the endemic equilibrium of an SIS age-structured epidemic model of a vertically as well as horizontally transmitted disease is investigated when the force of infection is of proportionate mixing assumption type. We also investigate the uniform weak disease persistence. (author)

  9. Implications for Particle Rotation and Vertical Mixing from Cassini CIRS Thermal Measurements of Saturn's Main Rings

    Science.gov (United States)

    Spilker, L. J.; Pilorz, S.; Pearl, J.; Altobelli, N.; Wallis, B.; Brooks, S.; Ferrari, C.; Showalter, M.; Flasar, M.

    2006-12-01

    The Cassini Composite Infrared Spectrometer (CIRS) obtained spatially resolved thermal infrared scans of Saturn's main rings (A, B and C, and Cassini Division) for both the lit and unlit faces of the rings over a variety of phase angles. The scans show ring temperatures decreasing with increasing solar phase angle. The largest ring temperatures are at a phase angle of zero degrees. These temperature differences with phase suggest that Saturn's main rings include a population of ring particles that spin slowly, possibly with a spin period greater than a few hours, given their low thermal inertia. For the B and A rings, the temperature is correlated with optical depth when viewed from the lit face, and anti- correlated when viewed from the unlit face. On the unlit face of the B ring, not only do the lowest temperatures correlate with the largest optical depths, but these temperatures are the same at both low and high phase angles, suggesting that little sunlight is penetrating these regions. The temperature differential from the lit to the unlit side of the rings is a strong, nearly linear, function of optical depth. This is consistent with the expectation that little sunlight penetrates to the dark side of the densest rings, but also suggests that little vertical mixing of ring particles is taking place in the A and B rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie".

  10. Effect of vertical mixing on short-term mycosporine-like amino acid synthesis in the Antarctic diatom, Thalasiossira sp.

    Directory of Open Access Journals (Sweden)

    Marcelo Pablo Hernando

    2011-12-01

    Full Text Available One of the adaptations whereby phytoplankton can alleviate damage induced by ultraviolet radiation (280-400 nm is the synthesis of mycosporine-like amino acids (MAAs. The synthesis of MAAs was studied after exposure of the Antarctic diatom Thalassiosira sp. isolated from Potter Cove (South Shetland Is., Antarctica to 2 treatments with a solar simulator: surface (Sfix and vertical mixing (Mix irradiance conditions. Light exposure was simulated in daily cycles with maximum irradiance at noon. Only 2 MAAs, Porphyra-334 (82-85% and Shinorine (15-18%, were identified. The concentration of the two compounds increased during experimental light exposure (50-55% and declined in the dark (10-15%. During the light period the synthesis rate of MAAs per unit of chlorophyll a was higher in the Sfix treatment (µ=0.17 h-1 than in the Mix treatment (µ=0.05 h-1. In spite of the higher MAA levels, low cell numbers were observed in the Sfix treatment, suggesting that the algae synthesized photoprotective compounds at the expense of growth. Our results document overlapping effects of both daily light cycles and vertical mixing affecting the synthesis of MAAs. This, and the high thermal dissipation of the ultraviolet B radiation energy (280-320 nm absorbed by these substances, suggest a rapid photoadaptive response of Thalasiossira sp. upon exposure to elevated irradiance in a stratified water column, as well as the complementary role of vertical mixing in photo-protection.

  11. Prefabricated Vertical Drain (PVD) and Deep Cement Mixing (DCM)/Stiffened DCM (SDCM) techniques for soft ground improvement

    Science.gov (United States)

    Bergado, D. T.; Long, P. V.; Chaiyaput, S.; Balasubramaniam, A. S.

    2018-04-01

    Soft ground improvement techniques have become most practical and popular methods to increase soil strength, soil stiffness and reduce soil compressibility including the soft Bangkok clay. This paper focuses on comparative performances of prefabricated vertical drain (PVD) using surcharge, vacuum and heat preloading as well as the cement-admixed clay of Deep Cement Mixing (DCM) and Stiffened DCM (SDCM) methods. The Vacuum-PVD can increase the horizontal coefficient of consolidation, Ch, resulting in faster rate of settlement at the same magnitudes of settlement compared to Conventional PVD. Several field methods of applying vacuum preloading are also compared. Moreover, the Thermal PVD and Thermal Vacuum PVD can increase further the coefficient of horizontal consolidation, Ch, with the associated reduction of kh/ks values by reducing the drainage retardation effects in the smear zone around the PVD which resulted in faster rates of consolidation and higher magnitudes of settlements. Furthermore, the equivalent smear effect due to non-uniform consolidation is also discussed in addition to the smear due to the mechanical installation of PVDs. In addition, a new kind of reinforced deep mixing method, namely Stiffened Deep Cement Mixing (SDCM) pile is introduced to improve the flexural resistance, improve the field quality control, and prevent unexpected failures of the Deep Cement Mixing (DCM) pile. The SDCM pile consists of DCM pile reinforced with the insertion of precast reinforced concrete (RC) core. The full scale test embankment on soft clay improved by SDCM and DCM piles was also analysed. Numerical simulations using the 3D PLAXIS Foundation finite element software have been done to understand the behavior of SDCM and DCM piles. The simulation results indicated that the surface settlements decreased with increasing lengths of the RC cores, and, at lesser extent, increasing sectional areas of the RC cores in the SDCM piles. In addition, the lateral movements

  12. Turbulent Mixing and Vertical Heat Transfer in the Surface Mixed Layer of the Arctic Ocean: Implication of a Cross-Pycnocline High-Temperature Anomaly

    Science.gov (United States)

    Kawaguchi, Yusuke; Takeda, Hiroki

    2017-04-01

    This study focuses on the mixing processes in the vicinity of surface mixed layer (SML) of the Arctic Ocean. Turbulence activity and vertical heat transfer are quantitatively characterized in the Northwind Abyssal Plain, based on the RV Mirai Arctic cruise, during the transition from late summer to early winter 2014. During the cruise, noticeable storm events were observed, which came over the ship's location and contributed to the deepening of the SML. According to the ship-based microstructure observation, within the SML, the strong wind events produced enhanced dissipation rates of turbulent kinetic energy in the order of magnitude of ɛ = 10-6-10-4W kg-1. On thermal variance dissipation rate, χ increases toward the base of SML, reaching O(10-7) K2 s-1, resulting in vertical heat flux of O(10) W m-2. During the occasional energetic mixing events, the near-surface warm water was transferred downward and penetrated through the SML base, creating a cross-pycnocline high-temperature anomaly (CPHTA) at approximately 20-30 m depth. Near CPHTA, the vertical heat flux was anomalously magnified to O(10-100) W m-2. Following the fixed-point observation, in the regions of marginal and thick ice zones, the SML heat content was monitored using an autonomous drifting buoy, UpTempO. During most of the ice-covered period, the ocean-to-ice turbulent heat flux was dominant, rather than the diapycnal heat transfer across the SML bottom interface.

  13. The understanding and experience of mixed emotions in 3-5-year-old children.

    Science.gov (United States)

    Smith, Joshua P; Glass, Daniel J; Fireman, Gary

    2015-01-01

    The term mixed emotions refers to the presence of two opposite-valence emotions toward a single target. Identifying when children begin to report experiencing and understanding mixed emotions is critical in identifying how skills such as adaptive functioning, coping strategies, environmental understanding, and socioemotional competence emerge. Prior research has shown that children as young as 5 years old can understand and experience mixed emotion, but perhaps appropriately sensitive methodologies can reveal these abilities in younger children. The present study evaluated 57 children between 3 and 5 years old for mixed emotion experience and understanding using an animated video clip in which a character experiences a mixed emotional episode. Ordinal logistic regression was utilized to examine the relation of gender, attention, and understanding of content to experience and understanding of mixed emotion. While only 12% of children reported experiencing mixed emotion while watching the clip, 49% of children-some as young as 3 years old-were able to recognize the mixed emotional experience of the character. Thus, mixed emotion understanding emerges earlier than previously identified and the expression of understanding may develop independently of the ability to report mixed emotion experience. These findings are discussed in relation to cognitive and developmental considerations.

  14. Mixed convection flow and heat transfer in a vertical wavy channel ...

    African Journals Online (AJOL)

    user

    forced convective flow in a fluid saturated porous medium channel bounded by two vertical parallel plates was presented by. Prathap Kumar ... width of the channel) vertical wavy and parallel flat wall. ...... In view of Eqs. (25) to (28) the boundary and interface conditions as defined in Eqs. (20) and (21) can be split as follows,.

  15. Single-Phase Crossflow Mixing in a Vertical Tube Bundle Geometry : An Experimental Study

    NARCIS (Netherlands)

    Mahmood, A.

    2011-01-01

    The vertical rod/tube bundle geometry has a wide variety of industrial applications. Typical examples are the core of light water nuclear reactors (LWR) and vertical tube steam generators. In the core of a LWR, primarily coolant flows upward but their also exist a flow in lateral direction, called

  16. Soret and Dufour effects on mixed convection from a vertical plate in power-law fluid saturated porous medium

    Directory of Open Access Journals (Sweden)

    Srinivasacharya D.

    2013-01-01

    Full Text Available Mixed convection heat and mass transfer along a vertical plate embedded in a power-law fluid saturated Darcy porous medium with Soret and Dufour effects is studied. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically using shooting method. The effect of Soret and Dufour parameters, power law index and mixed convection parameter on non-dimensional velocity, temperature and concentration fields are discussed. The variation of different parameters on heat and mass transfer rates is presented in tabular form.

  17. Vertical mixing in the marginal ice zone of the northern Barents Sea—Results from numerical model experiments

    Science.gov (United States)

    Sundfjord, Arild; Ellingsen, Ingrid; Slagstad, Dag; Svendsen, Harald

    2008-10-01

    Numerical ocean model simulations of the marginal ice zone (MIZ) of the Barents Sea have been made for the years 2003-2005. As part of a project studying carbon cycling in the northern Barents Sea MIZ, the model simulations provide a pre-history and context for interpretation of physical, biological and chemical field data collected during the annual project cruises in this period. Large-scale features as well as the temporal evolution of stratification and vertical mixing, from well-mixed winter conditions to the end of the ice-free season, are described. Modelled ice concentration at the times of the annual project cruises is in agreement with that inferred from satellite data. The simulated seasonal development of mixing and stratification in the MIZ, from winter via the melting period and through the productive summer season, is described. Turbulent mixing forced by tidal currents and wind episodes is examined, and resulting hydrographical conditions and diffusivities are compared with previously published measurements from the project cruises. The vertical and temporal extent to which such variable mixing influences the water column is realistically modelled, but the strength of mixing appears to be inaccurately distributed. Most importantly, differences in modelled and observed water-column stratification are identified. Enhanced near-surface mixing appears to protrude too deeply in the model, and the water column is excessively homogenized below the pycnocline. Experiments with the Mellor-Yamada Level 2.5 turbulence scheme are compared with those from the Richardson number scheme routinely used in the model. Some important differences between the schemes are identified, but both have similar problems with respect to resulting hydrography. Simulations with horizontal grid resolution increased from 4×4 km to 800×800 m allows for processes inducing significantly more energetic frontal mixing at the MIZ edge to be resolved.

  18. Teaching the Mixed Model Design: A Flowchart to Facilitate Understanding.

    Science.gov (United States)

    Mills, Jamie D.

    2005-01-01

    The Mixed Model (MM) design, sometimes known as a Split-Plot design, is very popular in educational research. This model can be used to examine the effects of several independent variables on a dependent variable and it offers a more powerful alternative to the completely randomized design. The MM design considers both a between-subjects factor,…

  19. Thermohaline circulation below the Ross Ice Shelf - A consequence of tidally induced vertical mixing and basal melting

    Science.gov (United States)

    Macayeal, D. R.

    1984-01-01

    The warmest water below parts of the Ross Ice Shelf resides in the lowest portion of the water column because of its high salinity. Vertical mixing caused by tidal stirring can thus induce ablation by lifting the warm but dense water into contact with the ice shelf. A numerical tidal simulation indicates that vertically well-mixed conditions predominate in the southeastern part of the sub-ice shelf cavity, where the water column thickness is small. Basal melting in this region is expected to be between 0.05 and 0.5 m/yr and will drive a thermohaline circulation having the following characteristics: high salinity shelf water (at - 1.8 C), formed by winter sea ice production in the open Ross Sea, flows along the seabed toward the tidal mixing fronts below the ice shelf; and meltwater (at -2.2 C), produced in the well-mixed region, flows out of the sub-ice shelf cavity along the ice shelf bottom. Sensitivity of this ablation process to climatic change is expected to be small because high salinity shelf water is constrained to have the sea surface freezing temperature.

  20. Some aspects of estimation of mixing height using vertical sodar records

    Energy Technology Data Exchange (ETDEWEB)

    Walczewski, J. [Inst. for Meteorology and Water Management, Cracow (Poland)

    1997-10-01

    The changes of the vertical range of sodar, depending on technical parameters, were illustrated by resulting changes of the height distribution of convective and elevated layers echoes. The extent of the difference`s in vertical range may be compartively large. In analyzed case, the maximal heights of convective plumes recorded at the same site with use of 3 types of sodar, were like 1:1.35:1.96. The relations of mean centers of gravity of frequency distributions were like 1:1.4:2.4. (au)

  1. Mixed convective heat transfer from a vertical plate embedded in a ...

    Indian Academy of Sciences (India)

    Abstract. The effect of melting and solute dispersion on heat and mass transfer in non-Darcy fluid flow over a vertical surface has been studied numerically in the present article. The flow is assumed to be laminar and steady state. Using similarity transformations, the governing boundary layer equations are transformed into ...

  2. Estimates of vertical mixings during a Lagrangian experiment off the Galician coast

    NARCIS (Netherlands)

    Lamy, F.; Sherwin, T.; Soetaert, K.E.R.; Herman, P.M.J.; Torres, R.

    2001-01-01

    An adjoint 1-D model was used to determine vertical diffusivity coefficients from temperature profiles collected within a filament escaping from the Galician coast following an upwelling event. The optimisation scheme ended with relatively high diffusivity values within the thermocline (9 x 10(-1)

  3. MHD mixed convection in a vertical annulus filled with Al2O3–water nanofluid considering nanoparticle migration

    International Nuclear Information System (INIS)

    Malvandi, A.; Safaei, M.R.; Kaffash, M.H.; Ganji, D.D.

    2015-01-01

    In the current study, an MHD mixed convection of alumina/water nanofluid inside a vertical annular pipe is investigated theoretically. The model used for the nanofluid mixture involves Brownian motion and thermophoretic diffusivities in order to take into account the effects of nanoparticle migration. Since the thermophoresis is the main mechanism of the nanoparticle migration, different temperature gradients have been imposed using the asymmetric heating. Considering hydrodynamically and thermally fully developed flow, the governing equations have been reduced to two-point ordinary boundary value differential equations and they have been solved numerically. It is revealed that the imposed thermal asymmetry would change the direction of nanoparticle migration and distorts the velocity, temperature and nanoparticle concentration profiles. Moreover, it is shown that the advantage of nanofluids in heat transfer enhancement is reduced in the presence of a magnetic field. - Highlights: • MHD mixed convection of alumina/water nanofluid inside a vertical annulus. • The effects of nanoparticle migration on rheological and thermophysical characteristics. • The effects of asymmetric heating on nanoparticle migration. • The effects of asymmetric heating on the heat transfer enhancement. • Inclusion of nanoparticles in presence of a magnetic field has a negative effect on performance

  4. Changes in viability of two Antarctic marine bacteria exposed to solar radiation in the water column: influence of vertical mixing

    International Nuclear Information System (INIS)

    Hernandez, E.A.

    2007-01-01

    The effect of UV radiation on two Antarctic marine bacterial strains (UVps and UVvi) was studied in the water column of Potter Cove (South Shetland, Antarctica). Quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. Assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between UVA and UVB, were performed. In other assays, a vertical mixing of 4 m/h was simulated. Both strains showed a significant decrease in viability (expressed as colony - forming units) when exposed to a surface UVB dose of 8.4 kJ m -2 . Studies with interferential filters showed a significant decrease at 0 and 1 m depth under both UV treatments. The UVps strain appeared to be more sensitive to UVB than to UVA. Damage produced by UVB was attenuated by the vertical mixing when the surface UVB dose was 4.8 kJ m -2 . This effect was not observed when surface UVB dose was 7.7 kJ m -2 . These results show that the negative effect caused by UVB radiation on the bacterio plankton would be significant only in the first meter of water column of the Antarctic coastal waters with high levels of suspended particulate material. (author) [es

  5. Vertical structure of pore pressure under surface gravity waves on a steep, megatidal, mixed sand-gravel-cobble beach

    Science.gov (United States)

    Guest, Tristan B.; Hay, Alex E.

    2017-01-01

    The vertical structure of surface gravity wave-induced pore pressure is investigated within the intertidal zone of a natural, steeply sloping, megatidal, mixed sand-gravel-cobble beach. Results from a coherent vertical array of buried pore pressure sensors are presented in terms of signal phase lag and attenuation as functions of oscillatory forcing frequency and burial depth. Comparison of the observations with the predictions of a theoretical poro-elastic bed response model indicates that the large observed phase lags and attenuation are attributable to interstitial trapped air. In addition to the dependence on entrapped air volume, the pore pressure phase and attenuation are shown to be sensitive to the hydraulic conductivity of the sediment, to the changing mean water depth during the tidal cycle, and to the redistribution/rearrangement of beach face material by energetic wave action during storm events. The latter result indicates that the effects on pore pressure of sediment column disturbance during instrument burial can persist for days to weeks, depending upon wave forcing conditions. Taken together, these results raise serious questions as to the practicality of using pore pressure measurements to estimate the kinematic properties of surface gravity waves on steep, mixed sand-gravel beaches.

  6. Mixed convective heat transfer from a vertical plate embedded in a ...

    Indian Academy of Sciences (India)

    In problems dealing with porous media, the effect of melting, radiation is important in indus- tries and technologies. The applications are found in situation such as geothermal systems, heating and cooling chamber, fossil fuel combustion, energy processes and Astro-physical flows. The effects of non-Darcy mixed convection ...

  7. Mixed convective heat transfer from a vertical plate embedded in a ...

    Indian Academy of Sciences (India)

    thermal radiaiton in a non-Darcy porous medium. J. Porous Media 8(5): 1–9. Prasad B D C N and Hemalatha K 2010 Non-Darcy mixed convection with thermal dispersion-Radiation in a saturated porous medium. The Open Transport Phenomena J. 2: 109–115. Sparrow E M, Patankar S V and Ramadhyani S 1977 Analysis ...

  8. Scrutiny of mixed convection flow of a nanofluid in a vertical channel

    Directory of Open Access Journals (Sweden)

    M. Fakour

    2014-11-01

    Full Text Available The laminar fully developed nanofluid flow and heat transfer in a vertical channel are investigated. By means of a new set of similarity variables, the governing equations are reduced to a set of three coupled equations with an unknown constant, which are solved along with the corresponding boundary conditions and the mass flux conservation relation by the homotopy perturbation method (HPM. We have tried to show reliability and performance of the present method compared with the numerical method (Runge–Kutta fourth-rate to solve this problem. The effects of the Grashof number (Gr, Prandtl number (Pr and Reynolds number (Re on the nanofluid flows are then investigated successively. The effects of the Brownian motion parameter (Nb, the thermophoresis parameter (Nt, and the Lewis number (Le on the temperature and nanoparticle concentration distributions are discussed. The current analysis shows that the nanoparticles can improve the heat transfer characteristics significantly for this flow problem.

  9. Variable-property effects in laminar aiding and opposing mixed convection of air in vertical tubes

    International Nuclear Information System (INIS)

    Nesreddine, H.; Galanis, N.; Nguyen, C.T.

    1997-01-01

    Mixed convection flow in tubes is encountered in many engineering applications, such as solar collectors, nuclear reactors, and compact heat exchangers. Here, a numerical investigation has been conducted in order to determine the effects of variable properties on the flow pattern and heat transfer performances in laminar developing ascending flow with mixed convection for two cases: in case 1 the fluid is heated, and in case 2 it is cooled. Calculations are performed for air at various Grashof numbers with a fixed entrance Reynolds number of 500 using both the Boussinesq approximation (constant-property model) and a variable-property model. In the latter case, the fluid viscosity and thermal conductivity are allowed to vary with absolute temperature according to simple power laws, while the density varies linearly with the temperature, and the heat capacity is assumed to be constant. The comparison between constant- and variable-property models shows a substantial difference in the temperature and velocity fields when the Grashof number |Gr| is increased. The friction factor is seen to be underpredicted by the Boussinesq approximation when the fluid is heated (case 1), while it is overpredicted for the cooling case (case 2). However, the effects on the heat transfer performance remain negligible except for cases with reverse flow. On the whole, the variable-property model predicts flow reversal at lower values of |Gr|, especially for flows with opposing buoyancy forces. The deviation in results is associated to the difference between the fluid bulk and the wall temperature

  10. Thermal fatigue analysis of vertical annulus with inner rotating cylinder induced by two temperature fluid mixing

    International Nuclear Information System (INIS)

    Miyano, Hiroshi; Narabayashi, Tadashi

    2011-01-01

    Mechanical seal for nuclear reactor coolant recirculation pump must purge the cold water supply from the outside. The cold purge water is flowing into the hot water zone in the pump through a narrow gap between pump shaft and casing over. On the mixing region of the cold purge water and hot water in the narrow gap, the random level temperature fluctuation occurs on the structural metal surface of casing cover and pump shaft. Then it could lead to cyclic thermal stress and fatigue damage. The experiments and analysis have done, made clear the mechanism of generation of temperature fluctuations. Also, it was studied how to measure the structure of the mixing zone temperature control and how to prevent the occurrence of a large temperature fluctuation. In addition, it is proposed the method of evaluating a random temperature fluctuation by using the envelope curve and its fatigue by OOR counting to applying to the evaluation of the similar random fluid temperature fluctuation problems. (author)

  11. Experimental study of mixed convection heat transfer in a vertical duct filled with metallic porous structures

    International Nuclear Information System (INIS)

    Venugopal, G.; Balaji, C.; Venkateshan, S.P.

    2010-01-01

    This paper reports the results of an experimental investigation to examine the potential of a simple and inexpensive porous insert developed specifically for augmenting heat transfer from the heated wall of a vertical duct under forced flow conditions. The porous insert used in the study consists of a stack of metallic perforated plates filled inside the duct. The characteristic features of the porous medium model on the hydrodynamic and heat transfer behavior have been investigated. The porous medium model developed in the present study shows thermo- hydrodynamic performance similar to those seen in metal foams. A correlation has been developed for predicting the Nusselt number from the geometry under consideration. The key novelty in the present work is the development of a new correlation for the Nusselt number that does not require any information from hydrodynamic studies. Over the range of parameters considered, the largest increase in the average Nusselt number of 4.52 times that for clear flow is observed with a porous material of porosity of 0.85. (authors)

  12. Mixed convection flow due to a vertical plate in the presence of heat source and chemical reaction

    Directory of Open Access Journals (Sweden)

    Rajeswari Seshadri

    2016-06-01

    Full Text Available In this paper, the hydromagnetic heat and mass transfer by mixed convection flow due to a vertical flat plate is considered for analysis. The governing equations are solved both analytically and numerically. The analytical solutions are obtained using the Homotopy Analysis Method (HAM while the numerical solutions are computed using Keller–Box method (K–B. Convergence of the Homotopy solutions for the governing non-dimensional equations are derived. A detailed error analysis is done to compute the average squared residual errors for flow, temperature and concentration. The optimal values of the convergence control parameter are computed for velocity and temperature. This study includes the effects of various parameters such as magnetic parameter, Grashof number, chemical reaction parameter, heat source parameter and Biot number on skin friction, heat and mass transfer rates as well on velocity, temperature and concentration profiles. Comparison of the HAM and K–B methods shows a very good agreement.

  13. Mixed convection boundary layer flow over a moving vertical flat plate in an external fluid flow with viscous dissipation effect.

    Directory of Open Access Journals (Sweden)

    Norfifah Bachok

    Full Text Available The steady boundary layer flow of a viscous and incompressible fluid over a moving vertical flat plate in an external moving fluid with viscous dissipation is theoretically investigated. Using appropriate similarity variables, the governing system of partial differential equations is transformed into a system of ordinary (similarity differential equations, which is then solved numerically using a Maple software. Results for the skin friction or shear stress coefficient, local Nusselt number, velocity and temperature profiles are presented for different values of the governing parameters. It is found that the set of the similarity equations has unique solutions, dual solutions or no solutions, depending on the values of the mixed convection parameter, the velocity ratio parameter and the Eckert number. The Eckert number significantly affects the surface shear stress as well as the heat transfer rate at the surface.

  14. Group method analysis of mixed convection stagnation-point flow of non-Newtonian nanofluid over a vertical stretching surface

    Science.gov (United States)

    Nabwey, Hossam A.; Boumazgour, Mohamed; Rashad, A. M.

    2017-07-01

    The group method analysis is applied to study the steady mixed convection stagnation-point flow of a non-Newtonian nanofluid towards a vertical stretching surface. The model utilized for the nanofluid incorporates the Brownian motion and thermophoresis effects. Applying the one-parameter transformation group which reduces the number of independent variables by one and thus, the system of governing partial differential equations has been converted to a set of nonlinear ordinary differential equations, and these equations are then computed numerically using the implicit finite-difference scheme. Comparison with previously published studies is executed and the results are found to be in excellent agreement. Results for the velocity, temperature, and the nanoparticle volume fraction profiles as well as the local skin-friction coefficient and local Nusselt number are presented in graphical and tabular forms, and discussed for different values of the governing parameters to show interesting features of the solutions.

  15. A Note on the Effect of Wind Waves on Vertical Mixing in Franks Tract, Sacramento–San Joaquin Delta, California

    Directory of Open Access Journals (Sweden)

    Nicole L. Jones

    2008-06-01

    Full Text Available A one-dimensional numerical model that simulates the effects of whitecapping waves was used to investigate the importance of whitecapping waves to vertical mixing at a 3-meter-deep site in Franks Tract in the Sacramento-San Joaquin Delta over an 11-day period. Locally-generated waves of mean period approximately 2 s were generated under strong wind conditions; significant wave heights ranged from 0 to 0.3 m. A surface turbulent kinetic energy flux was used to model whitecapping waves during periods when wind speeds > 5 m s-1 (62% of observations. The surface was modeled as a wind stress log-layer for the remaining 38% of the observations. The model results demonstrated that under moderate wind conditions (5–8 m s-1 at 10 m above water level, and hence moderate wave heights, whitecapping waves provided the dominant source of turbulent kinetic energy to only the top 10% of the water column. Under stronger wind (> 8 m s-1, and hence larger wave conditions, whitecapping waves provided the dominant source of turbulent kinetic energy over a larger portion of the water column; however, this region extended to the bottom half of the water column for only 7% of the observation period. The model results indicated that phytoplankton concentrations close to the bed were unlikely to be affected by the whitecapping of waves, and that the formation of concentration boundary layers due to benthic grazing was unlikely to be disrupted by whitecapping waves. Furthermore, vertical mixing of suspended sediment was unlikely to be affected by whitecapping waves under the conditions experienced during the 11-day experiment. Instead, the bed stress provided by tidal currents was the dominant source of turbulent kinetic energy over the bottom half of the water column for the majority of the 11-day period.

  16. A Nonlinear Model of Mix Coil Spring – Rubber for Vertical Suspension of Railway Vehicle

    Directory of Open Access Journals (Sweden)

    Dumitriu Mădălina

    2016-03-01

    Full Text Available The paper focuses on a nonlinear model to represent the mechanical behaviour of a mix coil spring - rubber used in the secondary suspension of passenger rail vehicles. The principle of the model relies on overlapping of the forces corresponding to three components - the elastic component, the viscous component and the dry friction component. The model has two sources on non-linearity, in the elastic force and the friction force, respectively. The main attributes of the model are made visible by its response to an imposed displacement-type harmonic excitation. The results thus obtained from the applications of numerical simulation show a series of basic properties of the model, namely the dependence on amplitude and the excitation frequency of the model response, as well as of its stiffness and damping.

  17. Mixed convective low flow pressure drop in vertical rod assemblies - II. Experimental validation

    International Nuclear Information System (INIS)

    Suh, K.Y.; Todreas, N.E.; Rohsenow, W.M.

    1987-01-01

    A predictive theory has been developed for the rod bundle frictional pressure drop characteristics under natural circulation conditions on the basis of the intra-assembly and intra-subchannel flow redistribution due to buoyancy for a wide spectrum of radial power profiles and for the geometric arrangements of practical design interest. Both the individual subchannel correlations and overall bundle design correlation have been formulated as the products of the buoyancy multipliers and the isothermal friction factors at the same Reynolds numbers. Two types of subchannel friction factors have been obtained: the standard one to be used with spatial average density and the modified one to be used with bulk mean density. A correlating procedure has been proposed to assess the local, global and skew buoyancy effects. The effects of interacting subchannel flows, developing mixed convective flow, wire wrapping, radial power skew and transition from laminar flow regime have been taken into account

  18. A single-column particle-resolved model for simulating the vertical distribution of aerosol mixing state: WRF-PartMC-MOSAIC-SCM v1.0

    Science.gov (United States)

    Curtis, Jeffrey H.; Riemer, Nicole; West, Matthew

    2017-11-01

    The PartMC-MOSAIC particle-resolved aerosol model was previously developed to predict the aerosol mixing state as it evolves in the atmosphere. However, the modeling framework was limited to a zero-dimensional box model approach without resolving spatial gradients in aerosol concentrations. This paper presents the development of stochastic particle methods to simulate turbulent diffusion and dry deposition of aerosol particles in a vertical column within the planetary boundary layer. The new model, WRF-PartMC-MOSAIC-SCM, resolves the vertical distribution of aerosol mixing state. We verified the new algorithms with analytical solutions for idealized test cases and illustrate the capabilities with results from a 2-day urban scenario that shows the evolution of black carbon mixing state in a vertical column.

  19. Mixing rates and vertical heat fluxes north of Svalbard from Arctic winter to spring

    Science.gov (United States)

    Meyer, Amelie; Fer, Ilker; Sundfjord, Arild; Peterson, Algot K.

    2017-06-01

    Mixing and heat flux rates collected in the Eurasian Basin north of Svalbard during the N-ICE2015 drift expedition are presented. The observations cover the deep Nansen Basin, the Svalbard continental slope, and the shallow Yermak Plateau from winter to summer. Mean quiescent winter heat flux values in the Nansen Basin are 2 W m-2 at the ice-ocean interface, 3 W m-2 in the pycnocline, and 1 W m-2 below the pycnocline. Large heat fluxes exceeding 300 W m-2 are observed in the late spring close to the surface over the Yermak Plateau. The data consisting of 588 microstructure profiles and 50 days of high-resolution under-ice turbulence measurements are used to quantify the impact of several forcing factors on turbulent dissipation and heat flux rates. Wind forcing increases turbulent dissipation seven times in the upper 50 m, and doubles heat fluxes at the ice-ocean interface. The presence of warm Atlantic Water close to the surface increases the temperature gradient in the water column, leading to enhanced heat flux rates within the pycnocline. Steep topography consistently enhances dissipation rates by a factor of four and episodically increases heat flux at depth. It is, however, the combination of storms and shallow Atlantic Water that leads to the highest heat flux rates observed: ice-ocean interface heat fluxes average 100 W m-2 during peak events and are associated with rapid basal sea ice melt, reaching 25 cm/d.

  20. Effects of thermophoresis and variable properties on mixed convection along a vertical wavy surface in a fluid saturated porous medium

    Directory of Open Access Journals (Sweden)

    Darbhasayanam Srinivasacharya

    2016-06-01

    Full Text Available This paper investigates the influence of thermophoresis on mixed convection heat and mass transfer flow over a vertical wavy surface in a porous medium with variable properties, namely variable viscosity and variable thermal conductivity. The effect of wavy surface is incorporated into non-dimensional equations by using suitable transformations and then transformed into non-linear ordinary differential equations by employing the similarity transformations and then solved numerically. The transport process of flow, heat and mass transfer in the boundary layer for aiding and opposing flow cases is discussed. The structure of flow, temperature and concentration fields in the Darcy porous media are more pronounced by complex interactions among variable viscosity, variable thermal conductivity, mixed convective parameter, thermophoresis and amplitude of the wavy surface. Increasing thermophoresis parameter enhances velocity profile, concentration distribution and Sherwood number while reduces Nusselt number. As increase in variable viscosity, temperature and concentration distributions are enhanced while velocity profile, Nusselt number and Sherwood numbers are reduced. This study finds applications in aerosol Technology, space technology and processes involving high temperatures.

  1. Interferometric and numerical study of free-, forced-, and mixed-convection heat transfer from heated vertical cylinders

    International Nuclear Information System (INIS)

    Choi, T.

    1985-01-01

    An external forced-, free-, and mixed convection heat transfer, with opposing buoyant and inertial forces from heated vertical cylinders, was experimentally and numerically investigated. A Mach-Zehnder interferometer was used for the experiment, and a discretization method with Patankar's algorithm SIMPLER was used for the numerical analysis. The mixed-convection behavior which appears during the transition from downward forced flow to free convection was simulated by quasi-unsteady state conditions. Forced downward flow is commonly used in gas-cooled nuclear reactors. The results of this study have a bearing on gas-cooled reactor safety. The transition was characterized by five distinctive heat and flow regimes. They are free-, suppressed-, vortex-, unsteady-, and forced-convection regimes. Local and average heat transfer coefficients were determined at forced flow rates from 30 to 130 cm/sec., over a temperature difference of 85 to 130 K with heater diameters of 12.7, 19.05, and 25.4 mm

  2. [Understanding what is lived by the being-couple in face of the prophylaxis of vertical HIV transmission].

    Science.gov (United States)

    Langendorf, Tassiane Ferreira; Padoin, Stela Maris de Mello; Paula, Cristiane Cardoso de; Souza, Ivis Emília de Oliveira

    2015-01-01

    To understand the couple's perspective, the experience of prevention care against the vertical transmission of HIV. Heidegger's phenomenological research conducted with 14 participants, through interviews from December / 2011 to February / 2012 in a hospital in the countryside of Rio Grande do Sul, Brazil. Analysis performed with Martin Heidegger's framework. RESULTS the being-couple unveiled the sense of fear, initially in the variation of dread when terrified due to the HIV infection discovery, and later in the horror variation when treatment was needed during gestation and finally in the terror variation when considering the chances of viral transmission to their child. Health care attention that enables the couple to assume a leading role in the prophylaxis of vertical transmission is recommended, which will reflect positively on the health of pregnant women and in reducing neonatal and infant mortality as a result from AIDS.

  3. Vertical Mixing of Desalination Reject Brine that Accumulates in Local Depressions in a Tidal Environment

    Science.gov (United States)

    Chow, A.; Shrivastava, I.; Adams, E. E.

    2016-02-01

    Environmental impacts from coastal desalination discharges are usually studied in the near field (region within 100 m of the outfall where dilution is caused mainly by discharge momentum) and/or the far field (region 10s of km or more from the outfall where mixing is affected mainly by large scale circulation). Here we consider an "intermediate field" scenario in which brine accumulates in local depressions within 1 km of the outfall, forming "puddles" on an otherwise flat bathymetry. Such puddles are hard to resolve with numerical far field models, but can impact benthic marine life, e.g., by allowing contaminants to accumulate or respiration of organic matter in the sediments to deplete dissolved oxygen. We model the puddle and the overlying water as a two layer system, with a stationary, dense, bottom layer containing diluted brine, and a top layer comprising ambient seawater that moves with the tidal current. Mass exchange between the two layers is modeled using formulations from the literature expressing the rate of entrainment from the bottom to the top layer as a function of Richardson number. Using idealized bathymetry, we investigate the evolution of the brine puddle as a function of the discharge flow rate and density difference relative to ambient, the near field dilution, and periodic tidal velocities. We study the periodic variation of the puddle volume and area, and determine the criteria for which the puddle might completely erode during a portion of the tidal cycle. Additionally we bookkeep the fate of passive tracers (salt, metals, dissolved oxygen) within the puddle, assuming they obey simple (zero or first order) kinetics. Finally we discuss the implications on benthic organisms living in the puddle and their exposures to prolonged periods of excess salinity, heavy metals, and lowered dissolved oxygen levels.

  4. Understanding the nanoscale local buckling behavior of vertically aligned MWCNT arrays with van der Waals interactions.

    Science.gov (United States)

    Li, Yupeng; Kim, Hyung-ick; Wei, Bingqing; Kang, Junmo; Choi, Jae-boong; Nam, Jae-Do; Suhr, Jonghwan

    2015-09-14

    The local buckling behavior of vertically aligned carbon nanotubes (VACNTs) has been investigated and interpreted in the view of a collective nanotube response by taking van der Waals interactions into account. To the best of our knowledge, this is the first report on the case of collective VACNT behavior regarding van der Waals force among nanotubes as a lateral support effect during the buckling process. The local buckling propagation and development of VACNTs were experimentally observed and theoretically analyzed by employing finite element modeling with lateral support from van der Waals interactions among nanotubes. Both experimental and theoretical analyses show that VACNTs buckled in the bottom region with many short waves and almost identical wavelengths, indicating a high mode buckling. Furthermore, the propagation and development mechanism of buckling waves follow the wave damping effect.

  5. Laminar mixed convection heat transfer in a vertical circular tube under buoyancy-assisted and opposed flows

    International Nuclear Information System (INIS)

    Mohammed, Hussein A.

    2008-01-01

    Laminar mixed convection heat transfer for assisted and opposed air flows in the entrance region of a vertical circular tube with the using of a uniform wall heat flux boundary condition has been experimentally investigated. The experimental setup was designed for determining the effect of flow direction and the effect of tube inclination on the surface temperature, local and average Nusselt numbers with Reynolds number ranged from 400 to 1600 and Grashof number from 2.0 x 10 5 to 6.2 x 10 6 . It was found that the circumferential surface temperature along the dimensionless tube length for opposed flow would be higher than that both of assisted flow and horizontal tube [Mohammed HA, Salman YK. Experimental investigation of combined convection heat transfer for thermally developing flow in a horizontal circular cylinder. Appl Therm Eng 2007;27(8-9):1522-33] due to the stronger free convective currents within the cross-section. The Nusselt number values would be lower for opposed flow than that for assisted flow. It was inferred that the behaviour of Nu x for opposed flow to be strongly dependent on the combination of Re and Gr numbers. Empirical equations expressing the average Nusselt numbers in terms of Grashof and Reynolds numbers were proposed for both assisted and opposed flow cases. The average heat transfer results were compared with previous literature and showed similar trend and satisfactory agreement

  6. Unsteady mixed convection flow of a micro-polar fluid near the stagnation point on a vertical surface

    Energy Technology Data Exchange (ETDEWEB)

    Lok, Y.Y. [Center for Academic Services, Kolej Universiti Teknikal Kebangsaan Malaysia, 75450 Ayer Keroh, Melaka (Malaysia); Amin, N. [Department of Mathematics, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Pop, I. [Faculty of Mathematics, University of Cluj, R-3400 Cluj, CP 253 (Romania)

    2006-12-15

    The unsteady mixed convection boundary-layer flow of a micro-polar fluid near the region of the stagnation point on a double-infinite vertical flat plate is studied. It is assumed that the unsteadiness is caused by the impulsive motion of the free stream velocity and by sudden increase or sudden decrease in the surface temperature from the uniform ambient temperature. The problem is reduced to a system of non-dimensional partial differential equations, which is solved numerically using the Keller-box method. This method may present well-behaved solutions for the transient (small time) solution and those of the steady-state flow (large time) solution. It was found that there is a smooth transition from the small-time solution (initial unsteady-state flow) to the large-time solution (final steady-state flow). Further, it is shown that for both assisting and opposing cases and a fixed value of the Prandtl number, the reduced steady-state skin friction and the steady-state heat transfer from the wall (or Nusselt number) decrease with the increase of the material parameter. On the other hand, it is shown that with the increase of the Prandtl number and a fixed value of the material parameter, the reduced steady-state skin friction decreases when the flow is assisting and it increases when the flow is opposing. (author)

  7. Seasonality in molecular and cytometric diversity of marine bacterioplankton: the reshuffling of bacterial taxa by vertical mixing

    KAUST Repository

    García, Francisca C.

    2015-07-17

    The ’cytometric diversity’ of phytoplankton communities has been studied based on single-cell properties, but the applicability of this method to characterize bacterioplankton has been unexplored. Here, we analysed seasonal changes in cytometric diversity of marine bacterioplankton along a decadal time-series at three coastal stations in the Southern Bay of Biscay. Shannon-Weaver diversity estimates and Bray-Curtis similarities obtained by cytometric and molecular (16S rRNA tag sequencing) methods were significantly correlated in samples from a 3.5-year monthly time-series. Both methods showed a consistent cyclical pattern in the diversity of surface bacterial communities with maximal values in winter. The analysis of the highly resolved flow cytometry time-series across the vertical profile showed that water column mixing was a key factor explaining the seasonal changes in bacterial composition and the winter increase in bacterial diversity in coastal surface waters. Due to its low cost and short processing time as compared to genetic methods, the cytometric diversity approach represents a useful complementary tool in the macroecology of aquatic microbes.

  8. Mixed Convective Fully Developed Flow in a Vertical Channel in the Presence of Thermal Radiation and Viscous Dissipation

    Directory of Open Access Journals (Sweden)

    Prasad K.V.

    2017-02-01

    Full Text Available The effect of thermal radiation and viscous dissipation on a combined free and forced convective flow in a vertical channel is investigated for a fully developed flow regime. Boussinesq and Roseseland approximations are considered in the modeling of the conduction radiation heat transfer with thermal boundary conditions (isothermal-thermal, isoflux-thermal, and isothermal-flux. The coupled nonlinear governing equations are also solved analytically using the Differential Transform Method (DTM and regular perturbation method (PM. The results are analyzed graphically for various governing parameters such as the mixed convection parameter, radiation parameter, Brinkman number and perturbation parameter for equal and different wall temperatures. It is found that the viscous dissipation enhances the flow reversal in the case of a downward flow while it counters the flow in the case of an upward flow. A comparison of the Differential Transform Method (DTM and regular perturbation method (PM methods shows the versatility of the Differential Transform Method (DTM. The skin friction and the wall temperature gradient are presented for different values of the physical parameters and the salient features are analyzed.

  9. Primary Student-Teachers' Conceptual Understanding of the Greenhouse Effect: A mixed method study

    Science.gov (United States)

    Ratinen, Ilkka Johannes

    2013-04-01

    The greenhouse effect is a reasonably complex scientific phenomenon which can be used as a model to examine students' conceptual understanding in science. Primary student-teachers' understanding of global environmental problems, such as climate change and ozone depletion, indicates that they have many misconceptions. The present mixed method study examines Finnish primary student-teachers' understanding of the greenhouse effect based on the results obtained via open-ended and closed-form questionnaires. The open-ended questionnaire considers primary student-teachers' spontaneous ideas about the greenhouse effect depicted by concept maps. The present study also uses statistical analysis to reveal respondents' conceptualization of the greenhouse effect. The concept maps and statistical analysis reveal that the primary student-teachers' factual knowledge and their conceptual understanding of the greenhouse effect are incomplete and even misleading. In the light of the results of the present study, proposals for modifying the instruction of climate change in science, especially in geography, are presented.

  10. Subkilometer-scale motions in the tropical tropopause layer from aircraft measurements: characterization and impact on vertical mixing

    Science.gov (United States)

    Podglajen, A.; Pfister, L.; Jensen, E. J.; Alexander, M. J.; Karcher, B.; Randel, W. J.; Bui, T. V.; Dean-Day, J. M.

    2016-12-01

    The El Niño-driven fire season in Indonesia, 2015, is recorded to have the most severe fire emissions since NASA's Earth Observation System (EOS) satellites started making observations of tropospheric pollutants from space. Carbon monoxide (CO), one of the major pollutants emitted during the fire season, has direct impacts on chemistry in the troposphere as a precursor to ozone O3 and carbon dioxide (CO2) and through interactions with the hydroxyl radical (OH) that increase the lifetime of methane (CH4). The relatively long chemical lifetime of CO (weeks to months) enables long-range transport as well as vertical transport into the upper troposphere and lower stratosphere (UTLS) region. In this study, measurements of CO from the Terra/MOPITT (Measurement of Pollution in the Troposphere) and Aura/MLS (Microwave Limb Sounder) are used to characterize the global impact of high CO emitted during the 2015 Indonesian fire season. The MOPITT and MLS instruments together provide a powerful tool for exploring global distributions of CO with overlap in the UTLS region. Simulations of CO from the Community Atmosphere Model with Chemistry (CAM-chem) are used to better understand transport pathways of CO from the surface into the lower stratosphere. We find that high concentrations of CO from the September-October 2015 Indonesian fires persisted in the UTLS throughout 2016, much longer than previous years with significant fire emissions.

  11. Chemical reaction and radiation effects on mixed convection heat and mass transfer over a vertical plate in power-law fluid saturated porous medium

    Directory of Open Access Journals (Sweden)

    D. Srinivasacharya

    2016-01-01

    Full Text Available Mixed convection heat and mass transfer along a vertical plate embedded in a power-law fluid saturated Darcy porous medium with chemical reaction and radiation effects is studied. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically using shooting method. A parametric study of the physical parameters involved in the problem is conducted and a representative set of numerical results is illustrated graphically.

  12. Understanding The Marketing Mix Of Smartphone Market From The Consumer Point Of View

    Directory of Open Access Journals (Sweden)

    Rahul Kumar Singh

    2015-08-01

    Full Text Available The purpose of this article to understand the marketing mix of the smartphone from consumers point of view that is consumers expectations from a smartphone. This article would help the producers understand the needs and wants of the customers regarding smartphones. The smartphone industry has lot of potential in it and we will witness more technological boom in the near future. And just coming up with a brilliant design will not serve the purpose but solving a particular problem would be more beneficial. So to solve this problem the producers need to understand what a customer wants from hisher smartphone now that is more specifications a better design a mid-range device etc. The articles centralize on the fact about creating awareness among the producers about the utility of the customers regarding smartphones so that the producers could make changes which could satisfy the demand and expectations of the customers regarding smartphones. The article will give you a preview of the competitors and their activity in the market at present. This article would be a great help to the smartphone companies to understand their customers and their needs in a better way.

  13. Cross diffusion effect on MHD mixed convection flow of nonlinear radiative heat and mass transfer of Casson fluid over a vertical plate

    Directory of Open Access Journals (Sweden)

    K. Ganesh Kumar

    2018-03-01

    Full Text Available A study on magnetohydrodynamic mixed convection flow of Casson fluid over a vertical plate has been modelled in the presence of Cross diffusion effect and nonlinear thermal radiation. The governing partial differential equations are remodelled into ordinary differential equations by using similarity transformation. The accompanied differential equations are resolved numerically by using Runge–Kutta–Fehlberg forth-fifth order along with shooting method (RKF45 Method. The results of various physical parameters on velocity and temperature profiles are given diagrammatically. The numerical values of the local skin friction coefficient, local Nusselt number and local Sherwood number also are shown in a tabular form. It is found that, effect of Dufour and Soret parameter increases the temperature and concentration component correspondingly. Keywords: Casson fluid, Nonlinear thermal radiation, Magnetic field, Cross diffusion effect, Vertical surface

  14. Understanding fuel magnetization and mix using secondary nuclear reactions in magneto-inertial fusion.

    Science.gov (United States)

    Schmit, P F; Knapp, P F; Hansen, S B; Gomez, M R; Hahn, K D; Sinars, D B; Peterson, K J; Slutz, S A; Sefkow, A B; Awe, T J; Harding, E; Jennings, C A; Chandler, G A; Cooper, G W; Cuneo, M E; Geissel, M; Harvey-Thompson, A J; Herrmann, M C; Hess, M H; Johns, O; Lamppa, D C; Martin, M R; McBride, R D; Porter, J L; Robertson, G K; Rochau, G A; Rovang, D C; Ruiz, C L; Savage, M E; Smith, I C; Stygar, W A; Vesey, R A

    2014-10-10

    Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs.

  15. Investigating Effect of Ignoring Hierarchical Data Structures on Accuracy of Vertical Scaling Using Mixed-Effects Rasch Model

    Science.gov (United States)

    Wang, Shudong; Jiao, Hong; Jin, Ying; Thum, Yeow Meng

    2010-01-01

    The vertical scales of large-scale achievement tests created by using item response theory (IRT) models are mostly based on cluster (or correlated) educational data in which students usually are clustered in certain groups or settings (classrooms or schools). While such application directly violated assumption of independent sample of person in…

  16. The positively phototactic reaction of daphnia magna straus: A contribution to the understanding of diurnal vertical migration

    NARCIS (Netherlands)

    Ringelberg, J.

    1964-01-01

    The present investigation was aimed at gaining more insight into the physiological mechanism underlying the diurnal vertical migration of planktonic animals. The experiments were carried out on Daphnia magna. Only reactions to decreases in light intensity were studied. Kinetical

  17. The Coupled Mars Dust and Water Cycles: Understanding How Clouds Affect the Vertical Distribution and Meridional Transport of Dust and Water.

    Science.gov (United States)

    Kahre, M. A.

    2015-01-01

    The dust and water cycles are crucial to the current Martian climate, and they are coupled through cloud formation. Dust strongly impacts the thermal structure of the atmosphere and thus greatly affects atmospheric circulation, while clouds provide radiative forcing and control the hemispheric exchange of water through the modification of the vertical distributions of water and dust. Recent improvements in the quality and sophistication of both observations and climate models allow for a more comprehensive understanding of how the interaction between the dust and water cycles (through cloud formation) affects the dust and water cycles individually. We focus here on the effects of clouds on the vertical distribution of dust and water, and how those vertical distributions control the net meridional transport of water. For this study, we utilize observations of temperature, dust and water ice from the Mars Climate Sounder (MCS) on the Mars Reconnaissance Orbiter (MRO) combined with the NASA ARC Mars Global Climate Model (MGCM). We demonstrate that the magnitude and nature of the net meridional transport of water between the northern and southern hemispheres during NH summer is sensitive to the vertical structure of the simulated aphelion cloud belt. We further examine how clouds influence the atmospheric thermal structure and thus the vertical structure of the cloud belt. Our goal is to identify and understand the importance of radiative/dynamic feedbacks due to the physical processes involved with cloud formation and evolution on the current climate of Mars.

  18. Who Is Overeducated and Why? Probit and Dynamic Mixed Multinomial Logit Analyses of Vertical Mismatch in East and West Germany

    Science.gov (United States)

    Boll, Christina; Leppin, Julian Sebastian; Schömann, Klaus

    2016-01-01

    Overeducation potentially signals a productivity loss. With Socio-Economic Panel data from 1984 to 2011 we identify drivers of educational mismatch for East and West medium and highly educated Germans. Addressing measurement error, state dependence and unobserved heterogeneity, we run dynamic mixed multinomial logit models for three different…

  19. Mixed

    Directory of Open Access Journals (Sweden)

    Pau Baya

    2011-05-01

    Full Text Available Remenat (Catalan (Mixed, "revoltillo" (Scrambled in Spanish, is a dish which, in Catalunya, consists of a beaten egg cooked with vegetables or other ingredients, normally prawns or asparagus. It is delicious. Scrambled refers to the action of mixing the beaten egg with other ingredients in a pan, normally using a wooden spoon Thought is frequently an amalgam of past ideas put through a spinner and rhythmically shaken around like a cocktail until a uniform and dense paste is made. This malleable product, rather like a cake mixture can be deformed pulling it out, rolling it around, adapting its shape to the commands of one’s hands or the tool which is being used on it. In the piece Mixed, the contortion of the wood seeks to reproduce the plasticity of this slow heavy movement. Each piece lays itself on the next piece consecutively like a tongue of incandescent lava slowly advancing but with unstoppable inertia.

  20. The effect of UV radiation on photosynthesis in an Antarctic diatom (Thalassiosira sp.): does vertical mixing matter?

    International Nuclear Information System (INIS)

    Hernando, Marcelo P.; Ferreyra, Gustavo A.

    2004-01-01

    Full text: The reduction of the Antarctic stratospheric ozone resulted in significant increases in ultraviolet B radiation (UVBR, 280-320 nm) reaching the surface of the ocean. A series of laboratory and field experiments were conducted at Potter Cove (25 de Mayo Is., South Shetland Is., Antarctica) to study the effects of UVBR on photosynthesis of a typical Antarctic bloom forming diatom (Thalassiosira sp.) in fixed and moving incubations. There were three irradiance treatments: PART (with only photosynthetic active radiation, PAR, 400- 700 nm), UVAT (with PAR and ultraviolet A radiation, UVAR, 320-400 nm) and UVBT (with PAR, UVAR and UVBR). The three treatments were incubated in the field and laboratory with a solar simulator (SOLSI) in fixed frames at 0.5 and 5 m depth (S fix and B fix , respectively), while for the moving incubations were done within 6 h cycles (Mix). Considering the field and laboratory pooled data, results suggest an overall 45-50 % photosynthesis inhibition of S fix incubations in relation with Mix ones. During SOLSI experiments no significant differences were found between irradiance treatments under normal and medium ozone concentrations. Under low ozone conditions, a 40 % reduction in photosynthesis was observed in the UVBT for S fix . In contrast, no significant differences were observed between the irradiance treatments for Mix. Field experiment showed results similar to the laboratory ones, but in this case not only S fix but Mix incubations presented a significant reduction in photosynthesis under low ozone. The differences between laboratory and field experiments are discussed in terms of the relative significance of UVBR dose and dose rate on both types of experiments. (author)

  1. Understanding Factors that Shape Gender Attitudes in Early Adolescence Globally: A Mixed-Methods Systematic Review.

    Science.gov (United States)

    Kågesten, Anna; Gibbs, Susannah; Blum, Robert Wm; Moreau, Caroline; Chandra-Mouli, Venkatraman; Herbert, Ann; Amin, Avni

    2016-01-01

    Early adolescence (ages 10-14) is a period of increased expectations for boys and girls to adhere to socially constructed and often stereotypical norms that perpetuate gender inequalities. The endorsement of such gender norms is closely linked to poor adolescent sexual and reproductive and other health-related outcomes yet little is known about the factors that influence young adolescents' personal gender attitudes. To explore factors that shape gender attitudes in early adolescence across different cultural settings globally. A mixed-methods systematic review was conducted of the peer-reviewed literature in 12 databases from 1984-2014. Four reviewers screened the titles and abstracts of articles and reviewed full text articles in duplicate. Data extraction and quality assessments were conducted using standardized templates by study design. Thematic analysis was used to synthesize quantitative and qualitative data organized by the social-ecological framework (individual, interpersonal and community/societal-level factors influencing gender attitudes). Eighty-two studies (46 quantitative, 31 qualitative, 5 mixed-methods) spanning 29 countries were included. Ninety percent of studies were from North America or Western Europe. The review findings indicate that young adolescents, across cultural settings, commonly express stereotypical or inequitable gender attitudes, and such attitudes appear to vary by individual sociodemographic characteristics (sex, race/ethnicity and immigration, social class, and age). Findings highlight that interpersonal influences (family and peers) are central influences on young adolescents' construction of gender attitudes, and these gender socialization processes differ for boys and girls. The role of community factors (e.g. media) is less clear though there is some evidence that schools may reinforce stereotypical gender attitudes among young adolescents. The findings from this review suggest that young adolescents in different cultural

  2. Understanding Factors that Shape Gender Attitudes in Early Adolescence Globally: A Mixed-Methods Systematic Review.

    Directory of Open Access Journals (Sweden)

    Anna Kågesten

    Full Text Available Early adolescence (ages 10-14 is a period of increased expectations for boys and girls to adhere to socially constructed and often stereotypical norms that perpetuate gender inequalities. The endorsement of such gender norms is closely linked to poor adolescent sexual and reproductive and other health-related outcomes yet little is known about the factors that influence young adolescents' personal gender attitudes.To explore factors that shape gender attitudes in early adolescence across different cultural settings globally.A mixed-methods systematic review was conducted of the peer-reviewed literature in 12 databases from 1984-2014. Four reviewers screened the titles and abstracts of articles and reviewed full text articles in duplicate. Data extraction and quality assessments were conducted using standardized templates by study design. Thematic analysis was used to synthesize quantitative and qualitative data organized by the social-ecological framework (individual, interpersonal and community/societal-level factors influencing gender attitudes.Eighty-two studies (46 quantitative, 31 qualitative, 5 mixed-methods spanning 29 countries were included. Ninety percent of studies were from North America or Western Europe. The review findings indicate that young adolescents, across cultural settings, commonly express stereotypical or inequitable gender attitudes, and such attitudes appear to vary by individual sociodemographic characteristics (sex, race/ethnicity and immigration, social class, and age. Findings highlight that interpersonal influences (family and peers are central influences on young adolescents' construction of gender attitudes, and these gender socialization processes differ for boys and girls. The role of community factors (e.g. media is less clear though there is some evidence that schools may reinforce stereotypical gender attitudes among young adolescents.The findings from this review suggest that young adolescents in different

  3. Understanding Factors that Shape Gender Attitudes in Early Adolescence Globally: A Mixed-Methods Systematic Review

    Science.gov (United States)

    Gibbs, Susannah; Blum, Robert Wm; Moreau, Caroline; Chandra-Mouli, Venkatraman; Herbert, Ann; Amin, Avni

    2016-01-01

    Background Early adolescence (ages 10–14) is a period of increased expectations for boys and girls to adhere to socially constructed and often stereotypical norms that perpetuate gender inequalities. The endorsement of such gender norms is closely linked to poor adolescent sexual and reproductive and other health-related outcomes yet little is known about the factors that influence young adolescents’ personal gender attitudes. Objectives To explore factors that shape gender attitudes in early adolescence across different cultural settings globally. Methods A mixed-methods systematic review was conducted of the peer-reviewed literature in 12 databases from 1984–2014. Four reviewers screened the titles and abstracts of articles and reviewed full text articles in duplicate. Data extraction and quality assessments were conducted using standardized templates by study design. Thematic analysis was used to synthesize quantitative and qualitative data organized by the social-ecological framework (individual, interpersonal and community/societal-level factors influencing gender attitudes). Results Eighty-two studies (46 quantitative, 31 qualitative, 5 mixed-methods) spanning 29 countries were included. Ninety percent of studies were from North America or Western Europe. The review findings indicate that young adolescents, across cultural settings, commonly express stereotypical or inequitable gender attitudes, and such attitudes appear to vary by individual sociodemographic characteristics (sex, race/ethnicity and immigration, social class, and age). Findings highlight that interpersonal influences (family and peers) are central influences on young adolescents’ construction of gender attitudes, and these gender socialization processes differ for boys and girls. The role of community factors (e.g. media) is less clear though there is some evidence that schools may reinforce stereotypical gender attitudes among young adolescents. Conclusions The findings from this

  4. Direct and indirect effects of vertical mixing, nutrients and ultraviolet radiation on the bacterioplankton metabolism in high-mountain lakes from southern Europe

    Science.gov (United States)

    Durán, C.; Medina-Sánchez, J. M.; Herrera, G.; Villar-Argaiz, M.; Villafañe, V. E.; Helbling, E. W.; Carrillo, P.

    2014-05-01

    As a consequence of global change, modifications in the interaction among abiotic stressors on aquatic ecosystems have been predicted. Among other factors, UVR transparency, nutrient inputs and shallower epilimnetic layers could alter the trophic links in the microbial food web. Currently, there are some evidences of higher sensitiveness of aquatic microbial organisms to UVR in opaque lakes. Our aim was to assess the interactive direct and indirect effects of UVR (through the excretion of organic carbon - EOC - by algae), mixing regime and nutrient input on bacterial metabolism. We performed in situ short-term experiments under the following treatments: full sunlight (UVR + PAR, >280 nm) vs. UVR exclusion (PAR only, >400 nm); ambient vs. nutrient addition (phosphorus (P; 30 μg PL-1) and nitrogen (N; up to final N : P molar ratio of 31)); and static vs. mixed regime. The experiments were conducted in three high-mountain lakes of Spain: Enol [LE], Las Yeguas [LY] and La Caldera [LC] which had contrasting UVR transparency characteristics (opaque (LE) vs. clear lakes (LY and LC)). Under ambient nutrient conditions and static regimes, UVR exerted a stimulatory effect on heterotrophic bacterial production (HBP) in the opaque lake but not in the clear ones. Under UVR, vertical mixing and nutrient addition HBP values were lower than under the static and ambient nutrient conditions, and the stimulatory effect that UVR exerted on HBP in the opaque lake disappeared. By contrast, vertical mixing and nutrient addition increased HBP values in the clear lakes, highlighting for a photoinhibitory effect of UVR on HBP. Mixed regime and nutrient addition resulted in negative effects of UVR on HBP more in the opaque than in the clear lakes. Moreover, in the opaque lake, bacterial respiration (BR) increased and EOC did not support the bacterial carbon demand (BCD). In contrast, bacterial metabolic costs did not increase in the clear lakes and the increased nutrient availability even

  5. Numerical simulations of natural or mixed convection in vertical channels: comparisons of level-set numerical schemes for the modeling of immiscible incompressible fluid flows

    International Nuclear Information System (INIS)

    Li, R.

    2012-01-01

    The aim of this research dissertation is at studying natural and mixed convections of fluid flows, and to develop and validate numerical schemes for interface tracking in order to treat incompressible and immiscible fluid flows, later. In a first step, an original numerical method, based on Finite Volume discretizations, is developed for modeling low Mach number flows with large temperature gaps. Three physical applications on air flowing through vertical heated parallel plates were investigated. We showed that the optimum spacing corresponding to the peak heat flux transferred from an array of isothermal parallel plates cooled by mixed convection is smaller than those for natural or forced convections when the pressure drop at the outlet keeps constant. We also proved that mixed convection flows resulting from an imposed flow rate may exhibit unexpected physical solutions; alternative model based on prescribed total pressure at inlet and fixed pressure at outlet sections gives more realistic results. For channels heated by heat flux on one wall only, surface radiation tends to suppress the onset of re-circulations at the outlet and to unify the walls temperature. In a second step, the mathematical model coupling the incompressible Navier-Stokes equations and the Level-Set method for interface tracking is derived. Improvements in fluid volume conservation by using high order discretization (ENO-WENO) schemes for the transport equation and variants of the signed distance equation are discussed. (author)

  6. How Do Children Who Understand Mixed Emotion Represent Them in Freehand Drawings of Themselves and Others?

    Science.gov (United States)

    Burkitt, Esther; Watling, Dawn

    2016-01-01

    This research is the first to assess children's representation of mixed emotion using a freehand drawing task. Two hundred and forty-one 5--11-year olds completed a drawing and a colour preference task. Children heard a condition appropriate vignette about themselves or a protagonist designed to evoke mixed emotion, and were asked to draw the self…

  7. Understanding discharge communication behaviours in a pediatric emergency care context: a mixed methods observation study protocol.

    Science.gov (United States)

    Curran, Janet A; Bishop, Andrea; Plint, Amy; MacPhee, Shannon; Zemek, Roger; Chorney, Jill; Jabbour, Mona; Porter, Stephen; Sawyer, Scott

    2017-04-17

    One of the most important transitions in the continuum of care for children is discharge to home. Optimal discharge communication between healthcare providers and caregivers (e.g., parents or other guardians) who present to the emergency department (ED) with their children is not well understood. The lack of policies and considerable variation in practice regarding discharge communication in pediatric EDs pose a quality and safety risk for children and their parents. The aim of this mixed methods study is to better understand the process and structure of discharge communication in a pediatric ED context to contribute to the design and development of discharge communication interventions. We will use surveys, administrative data and real-time video observation to characterize discharge communication for six common illness presentations in a pediatric ED: (1) asthma, (2) bronchiolitis, (3) abdominal pain, (4) fever, (5) diarrhea and vomiting, and (6) minor head injury. Participants will be recruited from one of two urban pediatric EDs in Canada. Video recordings will be analyzed using Observer XT. We will use logistic regression to identify potential demographic and visit characteristic cofounders and multivariate logistic regression to examine association between verbal and non-verbal behaviours and parent recall and comprehension. Video recording of discharge communication will provide an opportunity to capture important data such as temporality, sequence and non-verbal behaviours that might influence the communication process. Given the importance of better characterizing discharge communication to identify potential barriers and enablers, we anticipate that the findings from this study will contribute to the development of more effective discharge communication policies and interventions.

  8. Flow reversal in combined laminar mixed convection heat and mass transfer with phase change in a vertical channel

    International Nuclear Information System (INIS)

    Oulaid, Othmane; Benhamou, Brahim; Galanis, Nicolas

    2010-01-01

    This paper, deals with a numerical study of the effects of buoyancy forces on an upward, steady state, laminar flow of humid air in a vertical parallel-plate channel. The plates are wetted by a thin liquid water film and maintained at a constant temperature which is lower than that of the air entering the channel. A 2D fully elliptical model, associated with the Boussinesq assumption, is used to take into account axial diffusion. The solution of this mathematical model is based on the finite volume method and the velocity-pressure coupling is handled by the SIMPLER algorithm. Numerical results show that buoyancy forces have a significant effect on the hydrodynamic, thermal and mass fraction fields. Additionally, these forces induce flow reversal for high air temperatures and mass fractions at the channel entrance. It is established that heat transfer associated with phase change is, sometimes, more significant than sensible heat transfer. Furthermore, this importance depends on the mass fraction gradient. The conditions for the existence of flow reversal are presented in charts and analytical expressions specifying the critical thermal Grashof number as a function of the Reynolds number for different values of the solutal Grashof number and different aspect ratios of the channel.

  9. Cross diffusion effect on MHD mixed convection flow of nonlinear radiative heat and mass transfer of Casson fluid over a vertical plate

    Science.gov (United States)

    Ganesh Kumar, K.; Archana, M.; Gireesha, B. J.; Krishanamurthy, M. R.; Rudraswamy, N. G.

    2018-03-01

    A study on magnetohydrodynamic mixed convection flow of Casson fluid over a vertical plate has been modelled in the presence of Cross diffusion effect and nonlinear thermal radiation. The governing partial differential equations are remodelled into ordinary differential equations by using similarity transformation. The accompanied differential equations are resolved numerically by using Runge-Kutta-Fehlberg forth-fifth order along with shooting method (RKF45 Method). The results of various physical parameters on velocity and temperature profiles are given diagrammatically. The numerical values of the local skin friction coefficient, local Nusselt number and local Sherwood number also are shown in a tabular form. It is found that, effect of Dufour and Soret parameter increases the temperature and concentration component correspondingly.

  10. Vertical mixing as a determinant of trophic status in deep lakes: a case study from two lakes south of the Alps (Lake Garda and Lake Iseo

    Directory of Open Access Journals (Sweden)

    Paolo CORDELLA

    2003-09-01

    Full Text Available The identification of the factors and mechanisms determining a particular lake’s typology is crucial for the correct interpretation of trophic evolution. Nutrient concentrations are not the only properties which determine the trophic characteristics of lakes; others, such as morphometry, hydrology and climatic conditions, also have a major influence on the development of algal biomass and species composition. Large, deep lakes belong to a well defined typology. Their trophic status depends not only on algal nutrient loads, but also on the extent of the spring vertical mixing and renewal time. These factors are closely interrelated, for the actual renewal time approaches the theoretical renewal time only during the complete overturn. This paper compares the influence of different circulation patterns on the trophic status of two deep subalpine lakes with contrasting mixing characteristics. Lake Garda is the largest lake in Italy (S=368 km2, V=49 km3, Zmax=350 m. It is characterised by irregular circulation events (oligomixis; during the 1990s, complete homogenisation of the water column occurred in 1991 and 1999-2000. The years between these episodes showed an increase of hypolimnetic temperatures and a progressive vertical stratification of nutrients. Full overturn episodes were characterised by a sudden decrease of temperature and complete homogenisation of the chemical and physical variables along the water column, with a corresponding increase of nutrients and algal biomasses at the surface. In contrast, the last mixing involving the deepest waters in Lake Iseo (S= 60,9 km2, V=7,6 km3, Zmax=251 m occurred at the beginning of the 1980s, after which the reduced water renewal and the high trophic level resulted in a marked decrease in oxygen concentrations and in the establishment of conditions of anoxia during the 1990s. At present the lake is meromictic. In 1999 and 2000, when a complete overturn was observed in lakes Maggiore and Como as

  11. Understanding urban practitioners' perspectives on social-mix policies in Amsterdam: the importance of design and social space

    NARCIS (Netherlands)

    Lawton, P.

    2013-01-01

    Throughout recent decades, socially-mixed neighbourhoods have become a key element of urban policy and debate. This paper argues, with Amsterdam as an empirical case, that the design, layout and everyday use of social space—including public and private space—is of key importance in understanding the

  12. Final Report of the Grant: ''Vertical Transport and Mixing in Complex Terrain Airsheds''

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Joseph Harindra [Arizona State Univ., Tempe, AZ (United States); Anderson, James [Arizona State Univ., Tempe, AZ (United States); Boyer, Don [Arizona State Univ., Tempe, AZ (United States); Berman, Neil [Arizona State Univ., Tempe, AZ (United States)

    2004-12-29

    Stable stratification associated with nocturnal thermal circulation in areas of complex terrain leads to interesting and important phenomena that govern local meteorology and contaminant dispersion. Given that most urban areas are in complex topography, understanding and prediction of such phenomena are of immediate practical importance. This project dealt with theoretical, laboratory, numerical and field experimental studies aimed at understanding stratified flow and turbulence phenomena in urban areas, with particular emphasis on flow, turbulence and contaminant transport and diffusion in such flows. A myriad of new results were obtained and some of these results were used to improve the predictive capabilities of the models.

  13. Tritium, carbon-14, and iodine-129 as indicators for localized vertical recharge along an anticline in the Columbia River Basalts using a decay-corrected mixing model

    International Nuclear Information System (INIS)

    Hall, S.H.; Johnson, V.G.; Early, T.O.

    1987-11-01

    Tritium, 14 C, and 129 I in groundwater samples are used to demonstrate vertical recharge and measure flow velocity in the fractured and faulted Umtanum Ridge-Gable Mountain acticline, within the Columbia River Basalts, at a sampling site about 6 mi northeast of the proposed high-level nuclear waste repository at the Hanford Site, Washington State. Mixing model calculations yield an apparent downward migration rate of 15 to 19 ft/yr through a sequence of aquifers in the Wanapum Basalt that range in depth from 698 to 1373 ft. Estimates of the vertical flow rate in the overlying Saddle Mountains Basalt are somewhat higher. Hydrographs from neighboring wells, hydrostatic heads, pump test data, and the chemical composition of groundwater samples from the sampling well are consistent with interaquifer communication. Some hydrologic evidence from aquifers in this region suggests that, in the past, flow may have been upward. This possible reversal of flow may be associated with water table mounding in the unconfined aquifer, caused by waste disposal activities at the Hanford Site since World War II. 17 refs., 12 figs., 3 tabs

  14. Time Dependent MHD Nano-Second Grade Fluid Flow Induced by Permeable Vertical Sheet with Mixed Convection and Thermal Radiation.

    Science.gov (United States)

    Ramzan, Muhammad; Bilal, Muhammad

    2015-01-01

    The aim of present paper is to study the series solution of time dependent MHD second grade incompressible nanofluid towards a stretching sheet. The effects of mixed convection and thermal radiation are also taken into account. Because of nanofluid model, effects Brownian motion and thermophoresis are encountered. The resulting nonlinear momentum, heat and concentration equations are simplified using appropriate transformations. Series solutions have been obtained for velocity, temperature and nanoparticle fraction profiles using Homotopy Analysis Method (HAM). Convergence of the acquired solution is discussed critically. Behavior of velocity, temperature and concentration profiles on the prominent parameters is depicted and argued graphically. It is observed that temperature and concentration profiles show similar behavior for thermophoresis parameter Νt but opposite tendency is noted in case of Brownian motion parameter Νb. It is further analyzed that suction parameter S and Hartman number Μ depict decreasing behavior on velocity profile.

  15. Time Dependent MHD Nano-Second Grade Fluid Flow Induced by Permeable Vertical Sheet with Mixed Convection and Thermal Radiation.

    Directory of Open Access Journals (Sweden)

    Muhammad Ramzan

    Full Text Available The aim of present paper is to study the series solution of time dependent MHD second grade incompressible nanofluid towards a stretching sheet. The effects of mixed convection and thermal radiation are also taken into account. Because of nanofluid model, effects Brownian motion and thermophoresis are encountered. The resulting nonlinear momentum, heat and concentration equations are simplified using appropriate transformations. Series solutions have been obtained for velocity, temperature and nanoparticle fraction profiles using Homotopy Analysis Method (HAM. Convergence of the acquired solution is discussed critically. Behavior of velocity, temperature and concentration profiles on the prominent parameters is depicted and argued graphically. It is observed that temperature and concentration profiles show similar behavior for thermophoresis parameter Νt but opposite tendency is noted in case of Brownian motion parameter Νb. It is further analyzed that suction parameter S and Hartman number Μ depict decreasing behavior on velocity profile.

  16. Understanding Older People's Readiness for Receiving Telehealth: Mixed-Method Study.

    Science.gov (United States)

    van Houwelingen, Cornelis Tm; Ettema, Roelof Ga; Antonietti, Michelangelo Gef; Kort, Helianthe Sm

    2018-04-06

    The Dutch Ministry of Health has formulated ambitious goals concerning the use of telehealth, leading to subsequent changes compared with the current health care situation, in which 93% of care is delivered face-to-face. Since most care is delivered to older people, the prospect of telehealth raises the question of whether this population is ready for this new way of receiving care. To study this, we created a theoretical framework consisting of 6 factors associated with older people's intention to use technology. The objective of this study was to understand community-dwelling older people's readiness for receiving telehealth by studying their intention to use videoconferencing and capacities for using digital technology in daily life as indicators. A mixed-method triangulation design was used. First, a cross-sectional survey study was performed to investigate older people's intention to use videoconferencing, by testing our theoretical framework with a multilevel path analysis (phase 1). Second, for deeper understanding of older people's actual use of digital technology, qualitative observations of older people executing technological tasks (eg, on a computer, cell phone) were conducted at their homes (phase 2). In phase 1, a total of 256 people aged 65 years or older participated in the survey study (50.0% male; median age, 70 years; Q1-Q3: 67-76). Using a significance level of .05, we found seven significant associations regarding older people's perception of videoconferencing. Older people's (1) intention to use videoconferencing was predicted by their performance expectancy (odds ratio [OR] 1.26, 95% CI 1.13-1.39), effort expectancy (OR 1.23, 95% CI 1.07-1.39), and perceived privacy and security (OR 1.30, 95% CI 1.17-1.43); (2) their performance expectancy was predicted by their effort expectancy (OR 1.38, 95% CI 1.24-1.52); and (3) their effort expectancy was predicted by their self-efficacy (OR 1.55, 95% CI 1.42-1.68). In phase 2, a total of 6 men and 9

  17. Assessing and understanding sedentary behaviour in office-based working adults: a mixed-method approach

    Directory of Open Access Journals (Sweden)

    Clarice N. Waters

    2016-04-01

    Full Text Available Abstract Background Sedentary behaviours (SB can be characterized by low energy expenditure in a reclining position (e.g., sitting often associated with work and transport. Prolonged SB is associated with increased risk for chronic conditions, and due to technological advances, the working population is in office settings with high occupational exposure to SB. This study aims to assess SB among office workers, as well as barriers and strategies towards reducing SB in the work setting. Methods Using a mixed-methods approach guided by the socio-ecological framework, non-academic office workers from a professional school in a large public university were recruited. Of 180 eligible office workers, 40 enrolled and completed all assessments. Self-reported and objectively measured SB and activity levels were captured. Focus group discussion (FGD were conducted to further understand perceptions, barriers, and strategies to reducing workplace SB. Environmental factors were systematically evaluated by trained research staff using an adapted version of the Checklist for Health Promotion Environments at Worksites (CHEW. Thematic analysis of FGD was conducted and descriptive analysis of quantitative data was performed. Results The sample was mostly Chinese (n = 33, 80 % with a total of 24 (60 % female participants. Most participants worked five days a week for about 9.5(0.5 hrs/day. Accelerometer data show that participants spend the majority of their days in sedentary activities both on workdays (76.9 % and non-workdays (69.5 %. Self-report data confirm these findings with median sitting time of 420(180 minutes at work. From qualitative analyses, major barriers to reducing SB emerged, including the following themes: workplace social and cultural norms, personal factors, job scope, and physical building/office infrastructure. CHEW results confirm a lack of support from the physical infrastructure and information environment to reducing SB

  18. Assessing and understanding sedentary behaviour in office-based working adults: a mixed-method approach.

    Science.gov (United States)

    Waters, Clarice N; Ling, Er Pei; Chu, Anne H Y; Ng, Sheryl H X; Chia, Audrey; Lim, Yee Wei; Müller-Riemenschneider, Falk

    2016-04-27

    Sedentary behaviours (SB) can be characterized by low energy expenditure in a reclining position (e.g., sitting) often associated with work and transport. Prolonged SB is associated with increased risk for chronic conditions, and due to technological advances, the working population is in office settings with high occupational exposure to SB. This study aims to assess SB among office workers, as well as barriers and strategies towards reducing SB in the work setting. Using a mixed-methods approach guided by the socio-ecological framework, non-academic office workers from a professional school in a large public university were recruited. Of 180 eligible office workers, 40 enrolled and completed all assessments. Self-reported and objectively measured SB and activity levels were captured. Focus group discussion (FGD) were conducted to further understand perceptions, barriers, and strategies to reducing workplace SB. Environmental factors were systematically evaluated by trained research staff using an adapted version of the Checklist for Health Promotion Environments at Worksites (CHEW). Thematic analysis of FGD was conducted and descriptive analysis of quantitative data was performed. The sample was mostly Chinese (n = 33, 80 %) with a total of 24 (60 %) female participants. Most participants worked five days a week for about 9.5(0.5) hrs/day. Accelerometer data show that participants spend the majority of their days in sedentary activities both on workdays (76.9 %) and non-workdays (69.5 %). Self-report data confirm these findings with median sitting time of 420(180) minutes at work. From qualitative analyses, major barriers to reducing SB emerged, including the following themes: workplace social and cultural norms, personal factors, job scope, and physical building/office infrastructure. CHEW results confirm a lack of support from the physical infrastructure and information environment to reducing SB. There is high SB among office workers in this sample. We

  19. Validation of mixing height determined from vertical profiles of wind and temperature from the DMI-HIRLAM NWP model in comparison with readiosoundings

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, A.; Soerensen, J.H.; Nielsen, N.W. [Danish Meteorological Inst., DMI, Copenhagen (Denmark)

    1997-10-01

    A sensitivity study is performed of vertical profiles from the numerical weather prediction model DMI-HIRLAM (DMI-HIgh Resolution Limited Area Model). The study involves profiles of horizontal wind, temperature and humidity in the lower troposphere up to 2500 meter. Detailed comparisons of analysed as well as forecast profiles are made with measured data from several radio-sonde stations throughout Europe. Methods for estimating the Mixing Height (MH) based on a bulk Richardson number method, the Vogelezang and Holtslag method and parcel methods are also studied. The methods are inter-compared, and MH based on data from DMI-HIRLAM are compared with the corresponding MH based on radiosonde data. For convective conditions the MH estimates are also compared with subjective estimates of the MH. In this paper preliminary results mainly based on data from Jaegersborg (Copenhagen) are presented. Results based on data from 1994-95 show that the resemblance between measured profiles and the DMI-HIRLAM profiles is fairly good in general. Also the estimates of the MH based on DMI-HIRLAM data is in general of nearly the same quality as estimations based on observed data. However, especially in convective conditions there is a tendency by DMI-HIRLAM to underestimate the strength of the mixing and thereby relatively large errors in the estimates of the MH can occur. (au)

  20. The double mass hierarchy pattern: Simultaneously understanding quark and lepton mixing

    Science.gov (United States)

    Hollik, Wolfgang Gregor; Saldaña Salazar, Ulises Jesús

    2015-03-01

    The charged fermion masses of the three generations exhibit the two strong hierarchies m3 ≫m2 ≫m1. We assume that also neutrino masses satisfy mν3 >mν2 >mν1 and derive the consequences of the hierarchical spectra on the fermionic mixing patterns. The quark and lepton mixing matrices are built in a general framework with their matrix elements expressed in terms of the four fermion mass ratios, mu /mc, mc /mt, md /ms and ms /mb, and me /mμ, mμ /mτ, mν1 /mν2 and mν2 /mν3, for the quark and lepton sector, respectively. In this framework, we show that the resulting mixing matrices are consistent with data for both quarks and leptons, despite the large leptonic mixing angles. The minimal assumption we take is the one of hierarchical masses and minimal flavor symmetry breaking that strongly follows from phenomenology. No special structure of the mass matrices has to be assumed that cannot be motivated by this minimal assumption. This analysis allows us to predict the neutrino mass spectrum and set the mass of the lightest neutrino well below 0.01 eV. The method also gives the 1σ allowed ranges for the leptonic mixing matrix elements. Contrary to the common expectation, leptonic mixing angles are found to be determined solely by the four leptonic mass ratios without any relation to symmetry considerations as commonly used in flavor model building. Still, our formulae can be used to build up a flavor model that predicts the observed hierarchies in the masses - the mixing follows then from the procedure which is developed in this work.

  1. Understanding the desensitizing mechanism of olefin in explosives: shear slide of mixed HMX-olefin systems.

    Science.gov (United States)

    Zhang, Chaoyang; Cao, Xia; Xiang, Bin

    2012-04-01

    We simulated the shear slide behavior of typical mixed HMX-olefin systems and the effect of thickness of olefin layers (4-22 Å) on the behavior at a molecular level by considering two cases: bulk shear and interfacial shear. The results show that: (1) the addition of olefin into HMX can reduce greatly the shear sliding barriers relative to the pure HMX in the two cases, suggesting that the desensitizing mechanism of olefin is controlled dominantly by its good lubricating property; (2) the change of interaction energy in both systoles of shear slide is strongly dominated by van der Waals interaction; and (3) the thickness of olefin layers in the mixed explosives can influence its desensitizing efficiency. That is, the excessive thinness of olefin layers in the mixed explosive systems, for example, several angstroms, can lead to very high sliding barriers.

  2. Progress in understanding turbulent mixing induced by Rayleigh-Taylor and Richtmyer-Meshkov instabilities

    International Nuclear Information System (INIS)

    Zhou Ye; Remington, B.A.; Robey, H.F.; Cook, A.W.; Glendinning, S.G.; Dimits, A.; Buckingham, A.C.; Zimmerman, G.B.; Burke, E.W.; Peyser, T.A.; Cabot, W.; Eliason, D.

    2003-01-01

    Turbulent hydrodynamic mixing induced by the Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities occurs in settings as varied as exploding stars (supernovae), inertial confinement fusion (ICF) capsule implosions, and macroscopic flows in fluid dynamics facilities such as shock tubes. Turbulence theory and modeling have been applied to RT and RM induced flows and developed into a quantitative description of turbulence from the onset to the asymptotic end-state. The treatment, based on a combined approach of theory, direct numerical simulation (DNS), and experimental data analysis, has broad generality. Three areas of progress will be reported. First, a robust, easy to apply criteria will be reported for the mixing transition in a time-dependent flow. This allows an assessment of whether flows, be they from supernova explosions or ICF experiments, should be mixed down to the molecular scale or not. Second, through DNS, the structure, scaling, and spectral evolution of the RT instability induced flow will be inspected. Finally, using these new physical insights, a two-scale, dynamic mix model has been developed that can be applied to simulations of ICF experiments and astrophysics situations alike

  3. Creating Rich Portraits: A Mixed-Methods Approach to Understanding Profiles of Intrinsic and Extrinsic Motivations

    Science.gov (United States)

    Corpus, Jennifer Henderlong; Wormington, Stephanie V.; Haimovitz, Kyla

    2016-01-01

    A person-centered, mixed-methods approach (self-report surveys, semistructured interviews, school records) was used to characterize and evaluate profiles of intrinsic and extrinsic motivations among 243 third- through eighth-grade students. Cluster analysis suggested four distinct profiles: high quantity (high intrinsic, high extrinsic), primarily…

  4. Understanding the Impact of School Factors on School Counselor Burnout: A Mixed-Methods Study

    Science.gov (United States)

    Bardhoshi, Gerta; Schweinle, Amy; Duncan, Kelly

    2014-01-01

    This mixed-methods study investigated the relationship between burnout and performing noncounseling duties among a national sample of professional school counselors, while identifying school factors that could attenuate this relationship. Results of regression analyses indicate that performing noncounseling duties significantly predicted burnout…

  5. Understanding Student Stress and Coping in Elementary School: A Mixed-Method, Longitudinal Study

    Science.gov (United States)

    Sotardi, Valerie A.

    2016-01-01

    This mixed-method, longitudinal study examined daily school stress and coping strategies of elementary schoolchildren in the United States. Students (n = 65) between the ages of 7 and 11 years reported daily school stress measures for 8 weeks and completed individual stress and coping interviews. Results highlight critical relations between…

  6. Understanding University Students' Thoughts and Practices about Digital Citizenship: A Mixed Methods Study

    Science.gov (United States)

    Kara, Nuri

    2018-01-01

    The purpose of this study was to investigate university students' thoughts and practices concerning digital citizenship. An explanatory mixed methods design was used, and it involved collecting qualitative data after a quantitative phase in order to follow up on the quantitative data in more depth. In the first quantitative phase of the study, a…

  7. The Politics of Culture: Understanding Local Political Resistance to Detracking in Racially Mixed Schools.

    Science.gov (United States)

    Wells, Amy Stuart; Serna, Irene

    1996-01-01

    A 3-year study of 10 racially mixed schools implementing detracking shows how elite parents undermine the reforms by threatening flight, co-opting those educators who have power and authority, obtaining support of the "not-quite elite," and using bribes. (SK)

  8. Vertical distribution of microphysical properties of Arctic springtime low-level mixed-phase clouds over the Greenland and Norwegian seas

    Science.gov (United States)

    Mioche, Guillaume; Jourdan, Olivier; Delanoë, Julien; Gourbeyre, Christophe; Febvre, Guy; Dupuy, Régis; Monier, Marie; Szczap, Frédéric; Schwarzenboeck, Alfons; Gayet, Jean-François

    2017-10-01

    This study aims to characterize the microphysical and optical properties of ice crystals and supercooled liquid droplets within low-level Arctic mixed-phase clouds (MPCs). We compiled and analyzed cloud in situ measurements from four airborne spring campaigns (representing 18 flights and 71 vertical profiles in MPCs) over the Greenland and Norwegian seas mainly in the vicinity of the Svalbard archipelago. Cloud phase discrimination and representative vertical profiles of the number, size, mass and shape of ice crystals and liquid droplets are established. The results show that the liquid phase dominates the upper part of the MPCs. High concentrations (120 cm-3 on average) of small droplets (mean values of 15 µm), with an averaged liquid water content (LWC) of 0.2 g m-3 are measured at cloud top. The ice phase dominates the microphysical properties in the lower part of the cloud and beneath it in the precipitation region (mean values of 100 µm, 3 L-1 and 0.025 g m-3 for diameter, particle concentration and ice water content (IWC), respectively). The analysis of the ice crystal morphology shows that the majority of ice particles are irregularly shaped or rimed particles; the prevailing regular habits found are stellars and plates. We hypothesize that riming and diffusional growth processes, including the Wegener-Bergeron-Findeisen (WBF) mechanism, are the main growth mechanisms involved in the observed MPCs. The impact of larger-scale meteorological conditions on the vertical profiles of MPC properties was also investigated. Large values of LWC and high concentration of smaller droplets are possibly linked to polluted situations and air mass origins from the south, which can lead to very low values of ice crystal size and IWC. On the contrary, clean situations with low temperatures exhibit larger values of ice crystal size and IWC. Several parameterizations relevant for remote sensing or modeling studies are also determined, such as IWC (and LWC) - extinction

  9. Understanding experiences and outcomes in treatment of binge eating disorder and obesity: A mixed method study

    DEFF Research Database (Denmark)

    Meyer, Lene; Tjørnhøj-Thomsen, Tine; Lau, Marianne Engelbrecht

    Background: Binge eating disorder (BED) has recently been recognized as a diagnosis in the DSM-5 (Diagnostic Manual of Mental Disorders). BED is a severe eating disorder with physical, social and psychological consequences. The prevalence of BED is 2-3% and the majority develop weight problems...... and obesity. Treatment is found effective in reducing eating disorder symptomatology, but rarely leads to weight loss. It is still unknown how the issue of obesity can be addressed in BED treatment without increasing the risk of binge eating relapse. Objectives: The study is an explorative investigation...... of the outcome of a newly developed group based treatment that combines psychotherapy and either weight loss or well-being components for patients with binge eating disorders and obesity. Methods: The study uses a convergent mixed methods design. Qualitative and quantitative data are gathered using in...

  10. Understanding non-adherence in chronic heart failure: A mixed-method case study

    NARCIS (Netherlands)

    M. Oertle (M.); R.A. Bal (Roland)

    2010-01-01

    textabstractObjectives: Understanding non-adherence to guidelines in patients with co-morbidities by supplementing quantitative data through patient-centred qualitative research. It is hypothesised that clinical constraints and patient-related factors explain the vast proportion of non-adherence.

  11. Toward a More Nuanced Understanding of Intercoupling: Second-Generation Mixed Couples in Southern California

    Science.gov (United States)

    Morgan, Charlie V.

    2012-01-01

    Distinguishing between interethnic and interracial coupling offers new understandings about family diversity, as well as the assimilation of immigrants and their children. An analysis of the Children of Immigrants Longitudinal Study, a survey (N = 1,480) of the children of Asian and Latin American immigrants who live in Southern California, finds…

  12. A Mixed-Methods Approach to Understanding Loneliness and Depression in Older Adults

    Science.gov (United States)

    Barg, Frances K.; Huss-Ashmore, Rebecca; Wittink, Marsha N.; Murray, Genevra F.; Bogner, Hillary R.; Gallo, Joseph J.

    2009-01-01

    Objectives Depression in late life may be difficult to identify, and older adults often do not accept depression treatment offered. This article describes the methods by which we combined an investigator-defined definition of depression with a person-derived definition of depression in order to understand how older adults and their primary care providers overlapped and diverged in their ideas about depression. Methods We recruited a purposive sample of 102 persons aged 65 years and older with and without significant depressive symptoms on a standardized assessment scale (Center for Epidemiologic Studies–Depression scale) from primary care practices and interviewed them in their homes. We applied methods derived from anthropology and epidemiology (consensus analysis, semi-structured interviews, and standardized assessments) in order to understand the experience and expression of late-life depression. Results Loneliness was highly salient to older adults whom we asked to describe a depressed person or themselves when depressed. Older adults viewed loneliness as a precursor to depression, as self-imposed withdrawal, or as an expectation of aging. In structured interviews, loneliness in the week prior to interview was highly associated with depressive symptoms, anxiety, and hopelessness. Discussion An improved understanding of how older adults view loneliness in relation to depression, derived from multiple methods, may inform clinical practice. PMID:17114313

  13. Understanding the exercise habits of residents and attending physicians: a mixed methodology study.

    Science.gov (United States)

    Williams, Amy S; Williams, Casey D; Cronk, Nikole J; Kruse, Robin L; Ringdahl, Erika N; Koopman, Richelle J

    2015-02-01

    Although the benefits of exercise are well known, rates of exercise among residents are much lower than those of attendings or medical students. Little is known about the barriers that prevent residents from exercising regularly. This mixed methodology study identifies and compares these barriers for resident and attending physicians practicing in the same setting. We conducted three focus groups with first-year and senior residents and attending physicians in the University of Missouri Department of Family and Community Medicine from April to August 2013. We also administered a survey inquiring about exercise rates and habits to 110 resident and attending physicians in the same department using both paper and electronic versions. During both inpatient and non-inpatient rotations, residents reported exercising less than attending physicians. No residents exercised more than 150 minutes/week during inpatient rotations compared to 18.42% of attendings. Only 6.9% of residents exercised more than 150 minutes/week during non-inpatient rotations, compared to 25% of attendings. Residents and attendings reported different barriers to regular exercise. Residents reported lack of time for a traditional structured workout as a major barrier, which leads to an adversarial relationship between work and exercise. Residency programs can help residents overcome exercise barriers by reframing exercise expectations to include more frequent but brief periods of exercise during the workday and by developing a supportive exercise culture. Changing worksite environments to support physician exercise may improve physician wellness.

  14. Mixed quantum-classical electrodynamics: Understanding spontaneous decay and zero-point energy

    Science.gov (United States)

    Li, Tao E.; Nitzan, Abraham; Sukharev, Maxim; Martinez, Todd; Chen, Hsing-Ta; Subotnik, Joseph E.

    2018-03-01

    The dynamics of an electronic two-level system coupled to an electromagnetic field are simulated explicitly for one- and three-dimensional systems through semiclassical propagation of the Maxwell-Liouville equations. We consider three flavors of mixed quantum-classical dynamics: (i) the classical path approximation (CPA), (ii) Ehrenfest dynamics, and (iii) symmetrical quasiclassical (SQC) dynamics. Our findings are as follows: (i) The CPA fails to recover a consistent description of spontaneous emission, (ii) a consistent "spontaneous" emission can be obtained from Ehrenfest dynamics, provided that one starts in an electronic superposition state, and (iii) spontaneous emission is always obtained using SQC dynamics. Using the SQC and Ehrenfest frameworks, we further calculate the dynamics following an incoming pulse, but here we find very different responses: SQC and Ehrenfest dynamics deviate sometimes strongly in the calculated rate of decay of the transient excited state. Nevertheless, our work confirms the earlier observations by Miller [J. Chem. Phys. 69, 2188 (1978), 10.1063/1.436793] that Ehrenfest dynamics can effectively describe some aspects of spontaneous emission and highlights interesting possibilities for studying light-matter interactions with semiclassical mechanics.

  15. A microcosm approach on the potential effects of the vertical mixing of water masses over the primary productivity and phytoplankton biomass in the southern Brazilian coastal region

    Directory of Open Access Journals (Sweden)

    Flávia Marisa Prado Saldanha-Corrêa

    2004-12-01

    Full Text Available The vertical mixing between South Atlantic Central Water (SACW and Coastal Water (CW was simulated through microcosm experiments using the autochthonous phytoplankton community (fraction 20°C and oligotrophic. The phytoplankton growth potential of SACW, CW and an equivalent mixture of both (SACW+CW was compared, under 100, 30 and 10% of sunlight, at surface seawater temperature, in winter and summer conditions. Results demonstrate the importance of SACW as a natural eutrophication agent for the mixing layer, allowing the occurrence of new production by nutrient input, and also as a biological seeder through the development of its autochthonous phytoplankton community when it reaches the euphotic zone. The time lag for phytoplankton development during winter was around 4-5 days, against 1-2 days in summer. The hypothesis of physiological differences between surface and bottom phytoplankton populations from a deep (80 m and thermally homogeneous water column (common winter feature was also tested through the microcosm experiments. Results obtained clearly demonstrate that bottom water presented higher phytoplankton growth potential than the surface one.A mistura vertical entre a Água Central do Atlântico Sul (ACAS e a Água Costeira (AC foi simulada através de experimentos tipo microcosmos, com o fitoplâncton autóctone (fração 20°C e oligotrófica. O potencial trófico dessas águas e de uma mistura equivalente de ambas (ACAS+AC foi comparado a 100, 30 e 10% da luz solar, sob temperatura da água do mar na superfície, em condições de inverno e verão. Os resultados demonstram a importância da ACAS como agente fertilizador da camada de mistura tanto por introduzir nutrientes, favorecendo a ocorrência de produção nova, como pelo incremento da biomassa fitoplanctônica autóctone ao atingir a zona eufótica. A fase de adaptação observada no inverno foi de 4-5 dias enquanto no verão foi de 1-2 dias. A hipótese da existência de

  16. Understanding Factors Contributing to Inappropriate Critical Care: A Mixed-Methods Analysis of Medical Record Documentation.

    Science.gov (United States)

    Neville, Thanh H; Tarn, Derjung M; Yamamoto, Myrtle; Garber, Bryan J; Wenger, Neil S

    2017-11-01

    Factors leading to inappropriate critical care, that is treatment that should not be provided because it does not offer the patient meaningful benefit, have not been rigorously characterized. We explored medical record documentation about patients who received inappropriate critical care and those who received appropriate critical care to examine factors associated with the provision of inappropriate treatment. Medical records were abstracted from 123 patients who were assessed as receiving inappropriate treatment and 66 patients who were assessed as receiving appropriate treatment but died within six months of intensive care unit (ICU) admission. We used mixed methods combining qualitative analysis of medical record documentation with multivariable analysis to examine the relationship between patient and communication factors and the receipt of inappropriate treatment, and present these within a conceptual model. One academic health system. Medical records revealed 21 themes pertaining to prognosis and factors influencing treatment aggressiveness. Four themes were independently associated with patients receiving inappropriate treatment according to physicians. When decision making was not guided by physicians (odds ratio [OR] 3.76, confidence interval [95% CI] 1.21-11.70) or was delayed by patient/family (OR 4.52, 95% CI 1.69-12.04), patients were more likely to receive inappropriate treatment. Documented communication about goals of care (OR 0.29, 95% CI 0.10-0.84) and patient's preferences driving decision making (OR 0.02, 95% CI 0.00-0.27) were associated with lower odds of receiving inappropriate treatment. Medical record documentation suggests that inappropriate treatment occurs in the setting of communication and decision-making patterns that may be amenable to intervention.

  17. Influences of Dam Operations in Groundwater-Surface Water Mixing Zones: Towards Multiscale Understanding

    Science.gov (United States)

    Stegen, J.; Scheibe, T. D.; Chen, X.; Huang, M.; Arntzen, E.; Garayburu-Caruso, V. A.; Graham, E.; Johnson, T. C.; Strickland, C. E.

    2017-12-01

    The installation and operation of dams have myriad influences on ecosystems, from direct effects on hydrographs to indirect effects on marine biogeochemistry and terrestrial food webs. With > 50000 existing and > 3700 planned large dams world-wide there is a pressing need for holistic understanding of dam impacts. Such understanding is likely to reveal unrecognized opportunities to modify dam operations towards beneficial outcomes. One of the most dramatic influences of daily dam operations is the creation of `artificial intertidal zones' that emerge from short-term increases and decreases in discharge due to hydroelectric power demands; known as hydropeaking. There is a long history of studying the influences of hydropeaking on macrofauna such as fish and invertebrates, but only recently has significant attention been paid to the hydrobiogeochemical effects of hydropeaking. Our aim here is to develop an integrated conceptual model of the hydrobiogeochemical influences of hydropeaking. To do so we reviewed available literature focusing on hydrologic and/or biogeochemical influences of hydropeaking. Results from these studies were collated into a single conceptual model that integrates key physical (e.g., sediment transport, hydromorphology) and biological (e.g., timescale of microbiome response) processes. This conceptual model highlights non-intuitive impacts of hydropeaking, the presence of critical thresholds, and strong interactions among processes. When examined individually these features suggest context dependency, but when viewed through an integrated conceptual model, common themes emerge. We will further discuss a critical next step, which is the local to regional to global evaluation of this conceptual model, to enable multiscale understanding. We specifically propose a global `hydropeaking network' of researchers using common methods, data standards, and analysis techniques to quantify the hydrobiogeochemical effects of hydropeaking across biomes. We

  18. Understanding the patient experience through the power of film: A mixed method qualitative research study.

    Science.gov (United States)

    Ogston-Tuck, Sherri; Baume, Kath; Clarke, Chris; Heng, Simon

    2016-11-01

    For decades film has proved to be a powerful form of communication. Whether produced as entertainment, art or documentary, films have the capacity to inform and move us. Films are a highly attractive teaching instrument and an appropriate teaching method in health education. It is a valuable tool for studying situations most transcendental to human beings such as pain, disease and death. The objectives were to determine how this helps students engage with their role as health care professionals; to determine how they view the personal experience of illness, disease, disability or death; and to determine how this may impact upon their provision of patient care. The project was underpinned by the film selection determined by considerate review, intensive scrutiny, contemplation and discourse by the research team. 7 films were selected, ranging from animation; foreign, documentary, biopic and Hollywood drama. Each film was shown discretely, in an acoustic lecture theatre projected onto a large screen to pre-registration student nurses (adult, child and mental health) across each year of study from different cohorts (n=49). A mixed qualitative method approach consisted of audio-recorded 5-minute reactions post film screening; coded questionnaires; and focus group. Findings were drawn from the impact of the films through thematic analysis of data sets and subjective text condensation categorised as: new insights looking through patient eyes; evoking emotion in student nurses; spiritual care; going to the moves to learn about the patient experience; self discovery through films; using films to link theory to practice. Deeper learning through film as a powerful medium was identified in meeting the objectives of the study. Integration of film into pre registration curriculum, pedagogy, teaching and learning is recommended. The teaching potential of film stems from the visual process linked to human emotion and experience. Its impact has the power to not only help in

  19. Understanding students' readiness for interprofessional learning in an Asian context: a mixed-methods study.

    Science.gov (United States)

    Lestari, Endang; Stalmeijer, Renée E; Widyandana, Doni; Scherpbier, Albert

    2016-07-15

    Healthcare is generally provided by various health professionals acting together. Unfortunately, poor communication and collaboration within such healthcare teams often prevent its members from actively engaging in collaborative decision-making. Interprofessional education (IPE) which prepares health professionals for their collaborative role in the healthcare system may partially address this problem. This study aimed to investigate: 1) students' readiness for IPE in an Asian context, 2) the most important factors influencing students' perceptions of IPE, 3) the reasons underlying such perceptions, and 4) the factors mitigating or promoting their sense of readiness. To identify students' perceptions of IPE, we administered the Readiness for Interprofessional Learning Scale (RIPLS) to 398 in approximately 470 students from a range of health professions (medicine, nursing, midwifery and dentistry). The questionnaire included factors that could potentially influence readiness for IPE as found in the literature (GPA, etc.). To enhance our understanding of the responses to the RIPLS and to explore the reasons underlying them, we conducted 4 mono-professional focus group discussions (FGDs). We ran a statistical analysis on the quantitative data, while performing a thematic content analysis of the qualitative data using ATLAS.ti (version 7). Medical students seemed to be the most prepared for IPE. Students' perceptions of IPE were conditioned by the study programme they took, their GPA, intrinsic motivation and engagement in the student council connoting experience of working with students from different programmes. Focus groups further revealed that: 1) early exposure to clinical practice triggered both positive and negative perceptions of IPE and of its importance to learning communication and leadership skills, 2) medical students caused insecurity and disengagement in other students, 3) medical students felt pressured to be leaders, and 4) there was a need to clarify

  20. Understanding the Models of Community Hospital rehabilitation Activity (MoCHA): a mixed-methods study.

    Science.gov (United States)

    Gladman, John; Buckell, John; Young, John; Smith, Andrew; Hulme, Clare; Saggu, Satti; Godfrey, Mary; Enderby, Pam; Teale, Elizabeth; Longo, Roberto; Gannon, Brenda; Holditch, Claire; Eardley, Heather; Tucker, Helen

    2017-02-27

    To understand the variation in performance between community hospitals, our objectives are: to measure the relative performance (cost efficiency) of rehabilitation services in community hospitals; to identify the characteristics of community hospital rehabilitation that optimise performance; to investigate the current impact of community hospital inpatient rehabilitation for older people on secondary care and the potential impact if community hospital rehabilitation was optimised to best practice nationally; to examine the relationship between the configuration of intermediate care and secondary care bed use; and to develop toolkits for commissioners and community hospital providers to optimise performance. 4 linked studies will be performed. Study 1: cost efficiency modelling will apply econometric techniques to data sets from the National Health Service (NHS) Benchmarking Network surveys of community hospital and intermediate care. This will identify community hospitals' performance and estimate the gap between high and low performers. Analyses will determine the potential impact if the performance of all community hospitals nationally was optimised to best performance, and examine the association between community hospital configuration and secondary care bed use. Study 2: a national community hospital survey gathering detailed cost data and efficiency variables will be performed. Study 3: in-depth case studies of 3 community hospitals, 2 high and 1 low performing, will be undertaken. Case studies will gather routine hospital and local health economy data. Ward culture will be surveyed. Content and delivery of treatment will be observed. Patients and staff will be interviewed. Study 4: co-designed web-based quality improvement toolkits for commissioners and providers will be developed, including indicators of performance and the gap between local and best community hospitals performance. Publications will be in peer-reviewed journals, reports will be distributed

  1. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    Science.gov (United States)

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All

  2. Vertical Bisimulation

    NARCIS (Netherlands)

    Rensink, Arend; Gorrieri, Roberto

    We investigate criteria to relate specifications and implementations belonging to conceptually different abstraction levels, and propose vertical bisimulation as a candidate relation for this purpose. Vertical bisimulation is indexed by a function mapping abstract actions onto concrete processes,

  3. Toward a Simple Framework for Understanding the Influence of Litter Quality on Vertical and Horizontal Patterns of Soil Organic Matter Pools

    Science.gov (United States)

    Craig, M.; Phillips, R.

    2016-12-01

    Decades of research have revealed that plant litter quality fundamentally influences soil organic matter (SOM) properties. Yet we lack the predictive frameworks necessary to up-scale our understanding of these dynamics in biodiverse systems. Given that ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) plants are thought to differ in their litter quality, we ask whether this dichotomy represents a framework for understanding litter quality effects on SOM in temperate forests. To do this, we sampled soils from 250 spatially referenced locations within a 25-Ha plot where 28,000 trees had been georeferenced, and analyzed spatial patterns of plant and SOM properties. We then examined the extent to which the dominance of AM- versus EM-trees relates to 1) the quality of litter inputs to forest soils and 2) the horizontal and vertical distribution of SOM fractions. We found that leaf litters produced by EM-associated trees were generally of lower quality, having a lower concentration of soluble compounds and higher C:N. Concomitant with this, we observed higher soil C:N under EM trees. Interestingly, this reflected greater N storage in AM-dominated soils rather than greater C storage in EM-dominated soils. These patterns were driven by the storage of SOM in N-rich fractions in AM-dominated soils. Specifically, trees with high litter quality were associated with greater amounts of deep and mineral-associated SOM; pools that are generally considered stable. Our results support the recent contention that high-quality plant inputs should lead to the formation of stable SOM and suggest that the AM-EM framework may provide a way forward for representing litter quality effects on SOM in earth system models.

  4. Doppler Lidar Vertical Velocity Statistics Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-07-01

    Accurate height-resolved measurements of higher-order statistical moments of vertical velocity fluctuations are crucial for improved understanding of turbulent mixing and diffusion, convective initiation, and cloud life cycles. The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates coherent Doppler lidar systems at several sites around the globe. These instruments provide measurements of clear-air vertical velocity profiles in the lower troposphere with a nominal temporal resolution of 1 sec and height resolution of 30 m. The purpose of the Doppler lidar vertical velocity statistics (DLWSTATS) value-added product (VAP) is to produce height- and time-resolved estimates of vertical velocity variance, skewness, and kurtosis from these raw measurements. The VAP also produces estimates of cloud properties, including cloud-base height (CBH), cloud frequency, cloud-base vertical velocity, and cloud-base updraft fraction.

  5. The development of a balloonborne radiosonde to measure extremely low mixing ratios of nitric oxide in the atmosphere up to the altitude of 40 km first measured and stratospheric vertical profiles

    International Nuclear Information System (INIS)

    Weiler, K.H.

    1979-01-01

    Vertical profiles of NO were measured at midlatitudes by means of a balloonborne payload using the chemiluminescent principle. A newly developed pressure dependent turbofan enables sufficient main flow even under near vacuum conditions, as low as 3 mb a flight duration of 20 hours. The data are continuously transmitted via a PCM-system to the ground station. The whole instrument was sealed prior to the flight and opened above the clouds by telecommand in order to avoid contamination by water vapour. Extensive laboratory and in situ calibration procedures led for the first time to overall errors of less than +-5% for the midday mean value between 3 to 10 mb and +- 25% at 150 mb. The resolving power is better than 20 pptsub(v) (10 -11 ) depending on the actual temperature, maniflow, and pressure. At about 25 mb, the reduction in NO with the setting of the sun was observed. A very slow decrease in the mixing ratio was found, which agrees with measurements of other workers but not with present model predictions. The mixing ratio between 7 and 10 mb was between 3 and 4 ppbsub(v) (10 -9 ). The minimum mixing ratio of about 0.07 ppbsub(v) was observed at about 60 mb. Also a hysteresis between ascent and descent was observed. It is concluded that the different diurnal variations of NO are strongly dependent on vertical exchange processes, scattering processes, and the surface albedo. (orig.) [de

  6. Understanding Smart Home Sensor Data for Ageing in Place Through Everyday Household Routines: A Mixed Method Case Study.

    Science.gov (United States)

    van Kasteren, Yasmin; Bradford, Dana; Zhang, Qing; Karunanithi, Mohan; Ding, Hang

    2017-06-13

    An ongoing challenge for smart homes research for aging-in-place is how to make sense of the large amounts of data from in-home sensors to facilitate real-time monitoring and develop reliable alerts. The objective of our study was to explore the usefulness of a routine-based approach for making sense of smart home data for the elderly. Maximum variation sampling was used to select three cases for an in-depth mixed methods exploration of the daily routines of three elderly participants in a smart home trial using 180 days of power use and motion sensor data and longitudinal interview data. Sensor data accurately matched self-reported routines. By comparing daily movement data with personal routines, it was possible to identify changes in routine that signaled illness, recovery from bereavement, and gradual deterioration of sleep quality and daily movement. Interview and sensor data also identified changes in routine with variations in temperature and daylight hours. The findings demonstrated that a routine-based approach makes interpreting sensor data easy, intuitive, and transparent. They highlighted the importance of understanding and accounting for individual differences in preferences for routinization and the influence of the cyclical nature of daily routines, social or cultural rhythms, and seasonal changes in temperature and daylight hours when interpreting information based on sensor data. This research has demonstrated the usefulness of a routine-based approach for making sense of smart home data, which has furthered the understanding of the challenges that need to be addressed in order to make real-time monitoring and effective alerts a reality. ©Yasmin van Kasteren, Dana Bradford, Qing Zhang, Mohan Karunanithi, Hang Ding. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 13.06.2017.

  7. An Exploratory Sequential Mixed Methods Approach to Understanding Researchers’ Data Management Practices at UVM: Findings from the Qualitative Phase

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Berman

    2017-03-01

    Full Text Available This is the first in a series of articles reporting on a study of researcher data management practices and data services at the University of Vermont. The objective of this article is to report on the first qualitative phase of an exploratory sequential mixed methods research design focused on researcher data management practices and related institutional research data services. The aim of this study is to understand data management behaviors of faculty at the University of Vermont (UVM, a higher-research activity Research University, in order to guide the development of campus research data management services. The population of study was all faculty who received National Science Foundation (NSF grants between 2011 and 2014 who were required to submit a data management plan (DMP; qualitative data was collected in two forms: (1 semi-structured interviews and (2 document analysis of data management plans. From a population of 47 researchers, six were included in the interview sample, representing a broad range of disciplines and NSF Directorates, and 35 data management plans were analyzed. Three major themes were identified through triangulation of qualitative data sources: data management activities, including data dissemination and data sharing; institutional research support and infrastructure barriers; and perceptions of data management plans and attitudes towards data management planning. The themes articulated in this article will be used to design a survey for the second quantitative phase of the study, which will aim to more broadly generalize data management activities at UVM across all disciplines.

  8. Understanding transitions in care from hospital to homeless shelter: a mixed-methods, community-based participatory approach.

    Science.gov (United States)

    Greysen, S Ryan; Allen, Rebecca; Lucas, Georgina I; Wang, Emily A; Rosenthal, Marjorie S

    2012-11-01

    Coordinated transitions from hospital to shelter for homeless patients may improve outcomes, yet patient-centered data to guide interventions are lacking. To understand patients' experiences of transitions from hospital to a homeless shelter, and determine aspects of these experiences associated with perceived quality of these transitions. Mixed methods with a community-based participatory research approach, in partnership with personnel and clients from a homeless shelter. Ninety-eight homeless individuals at a shelter who reported at least one acute care visit to an area hospital in the last year. Using semi-structured interviews, we collected quantitative and qualitative data about transitions in care from the hospital to the shelter. We analyzed qualitative data using the constant comparative method to determine patients' perspectives on the discharge experience, and we analyzed quantitative data using frequency analysis to determine factors associated with poor outcomes from patients' perspective. Using qualitative analysis, we found homeless participants with a recent acute care visit perceived an overall lack of coordination between the hospital and shelter at the time of discharge. They also described how expectations of suboptimal coordination exacerbate delays in seeking care, and made three recommendations for improvement: 1) Hospital providers should consider housing a health concern; 2) Hospital and shelter providers should communicate during discharge planning; 3) Discharge planning should include safe transportation. In quantitative analysis of recent hospital experiences, 44 % of participants reported that housing status was assessed and 42 % reported that transportation was discussed. Twenty-seven percent reported discharge occurred after dark; 11 % reported staying on the streets with no shelter on the first night after discharge. Homeless patients in our community perceived suboptimal coordination in transitions of care from the hospital to the

  9. An Exploratory Sequential Mixed Methods Approach to Understanding Researchers’ Data Management Practices at UVM: Findings from the Quantitative Phase

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Berman

    2017-03-01

    Full Text Available This is the second in a series of articles reporting on a study of researcher data management practices and data services at the University of Vermont. This article reports on the second quantitative phase of an exploratory sequential mixed methods research design focused on researcher data management practices and related institutional support and services. The study aims to understand data management activities and challenges of faculty at the University of Vermont (UVM, a higher research activity Research University, in order to develop appropriate research data services (RDS. Data was collected via a survey, built on themes from the initial qualitative data analysis from the first phase of this study. The survey was distributed to a nonrandom census sample of full-time UVM faculty and researchers (P=1,190; from this population, a total of 319 participants completed the survey for a 26.8% response rate. The survey collected information on five dimensions of data management: data management activities; data management plans; data management challenges; data management support; and attitudes and behaviors towards data management planning. Frequencies, cross tabulations, and chi-square tests of independence were calculated using demographic variables including gender, rank, college, and discipline. Results from the analysis provide a snapshot of research data management activities at UVM, including types of data collected, use of metadata, short- and long-term storage of data, and data sharing practices. The survey identified key challenges to data management, including data description (metadata and sharing data with others; this latter challenge is particular impacted by confidentiality issues and lack of time, personnel, and infrastructure to make data available. Faculty also provided insight to RDS that they think UVM should support, as well as RDS they were personally interested in. Data from this study will be integrated with data from the

  10. Understanding the Impact of Childhood Sexual Abuse on Men's Risk Behavior: Protocol for a Mixed-Methods Study.

    Science.gov (United States)

    Downing, Martin J; Brown, Dominique; Steen, Jeffrey; Benoit, Ellen

    2018-02-26

    Childhood sexual abuse (CSA) remains a critical public health issue among black and Latino men who have sex with men (MSM), as it is associated with multiple negative outcomes including substance misuse, poor mental health, revictimization, and high-risk sexual behavior. Most CSA research with MSM relies on quantitative assessment that often precludes consideration of cultural variations in how formative sexual experiences are understood and is based on inconsistent or overly restrictive definitions of abuse, and therefore may fail to detect certain abusive experiences (eg, those involving female perpetrators), which can have harmful health consequences if they remain unrecognized. The objective of this study is to overcome existing limitations in the literature by drawing on perspectives of black and Latino MSM and men who have sex with men and women (MSMW), as well as relevant service providers to better understand the role of, and the need to include, sexual abuse histories (eg, CSA) in treatment and counseling settings, with the long-term goal of improving assessment and health outcomes. We will conduct mixed-methods interviews, framed by an intersectionality approach, with 80 black and Latino men (40 MSM and 40 MSMW) in New York City (NYC), exploring appraisals of their formative sexual experiences, including those described as consensual but meeting criteria for CSA. We will also interview 30 local service providers representing substance abuse treatment, mental health care, and HIV prevention and outreach. The study was launched in May 2017. This formative research will inform testable approaches to assessing and incorporating sexual abuse history into substance abuse treatment and other health and mental health services used by men with such histories. ©Martin J Downing Jr, Dominique Brown, Jeffrey Steen, Ellen Benoit. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 26.02.2018.

  11. Metric of the 2–6 day sea-surface temperature response to wind stress in the Tropical Pacific and its sensitivity to the K-Profile Parameterization of vertical mixing

    KAUST Repository

    Wagman, Benjamin M.

    2014-05-04

    Uncertainty in wind forcing has long hampered direct tests of ocean model output against observations for the purpose of refining the boundary layer K-Profile Parameterization (KPP) of oceanic vertical mixing. Considered here is a short-term metric that could be sensitive to the ways in which the KPP directly affects the adjustment of sea surface temperatures for a given change in wind stress. In particular a metric is developed based on the lagged correlation between the 2–6 day filtered wind stress and sea surface temperature. The metric is normalized by estimated observational and model uncertainties such that the significance of differences may be assessed. For this purpose multiple wind reanalysis products and their blended combinations were used to represent the range of forcing uncertainty, while perturbed KPP parameter model runs explore the sensitivity of the metric to the parameterization of vertical mixing. The correlation metric is sensitive to perturbations to most KPP parameters, in ways that accord with expectations, although only a few parameters show a sensitivity on the same order as the sensitivity to switching between wind products. This suggests that uncertainties in wind forcing continue to be a significant limitation for applying direct observational tests of KPP physics. Moreover, model correlations are biased high, suggesting that the model lacks or does not resolve sources of variability on the 2–6 day time scale.

  12. Understanding the Influence Career Paths Have on Community and Technical College Chief Business Officers' Satisfaction with Their Position: A Mixed Method Investigation

    Science.gov (United States)

    File, Carter L.

    2013-01-01

    This study was undertaken to understand whether a community or technical college chief business officer's career line influenced the lived experience of job satisfaction. This mixed method study was conducted in a two-phase approach using the Explanatory Design: Participant Selection Model variant. An initial quantitative survey was conducted from…

  13. A Note on Variable Viscosity and Chemical Reaction Effects on Mixed Convection Heat and Mass Transfer Along a Semi-Infinite Vertical Plate

    Directory of Open Access Journals (Sweden)

    Mostafa A. A. Mahmoud

    2007-01-01

    Full Text Available In the present study, an analysis is carried out to study the variable viscosity and chemical reaction effects on the flow, heat, and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by using the shooting method. The effects of different parameters on the dimensionless velocity, temperature, and concentration profiles are shown graphically. In addition, tabulated results for the local skin-friction coefficient, the local Nusselt number, and the local Sherwood number are presented and discussed.

  14. How does interannual trophic variability caused by vertical water mixing affect reproduction and population density of Daphnia longispina group in Lake Iseo, a deep stratifying lake in Italy?

    NARCIS (Netherlands)

    Leoni, B.; Garibaldi, L.; Gulati, R.D.

    2014-01-01

    Lake Iseo is a deep meromictic lake located in Italy. During the past 20 years (1993–2013), the lake has experienced complete mixing of the water column only in spring 2005 and 2006. The full overturn episodes in these 2 years resulted in an increase in nutrients in both years, but an increase in

  15. Comparison of the GOSAT TANSO-FTS TIR CH volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations

    Directory of Open Access Journals (Sweden)

    K. S. Olsen

    2017-10-01

    Full Text Available The primary instrument on the Greenhouse gases Observing SATellite (GOSAT is the Thermal And Near infrared Sensor for carbon Observations (TANSO Fourier transform spectrometer (FTS. TANSO-FTS uses three short-wave infrared (SWIR bands to retrieve total columns of CO2 and CH4 along its optical line of sight and one thermal infrared (TIR channel to retrieve vertical profiles of CO2 and CH4 volume mixing ratios (VMRs in the troposphere. We examine version 1 of the TANSO-FTS TIR CH4 product by comparing co-located CH4 VMR vertical profiles from two other remote-sensing FTS systems: the Canadian Space Agency's Atmospheric Chemistry Experiment FTS (ACE-FTS on SCISAT (version 3.5 and the European Space Agency's Michelson Interferometer for Passive Atmospheric Sounding (MIPAS on Envisat (ESA ML2PP version 6 and IMK-IAA reduced-resolution version V5R_CH4_224/225, as well as 16 ground stations with the Network for the Detection of Atmospheric Composition Change (NDACC. This work follows an initial inter-comparison study over the Arctic, which incorporated a ground-based FTS at the Polar Environment Atmospheric Research Laboratory (PEARL at Eureka, Canada, and focuses on tropospheric and lower-stratospheric measurements made at middle and tropical latitudes between 2009 and 2013 (mid-2012 for MIPAS. For comparison, vertical profiles from all instruments are interpolated onto a common pressure grid, and smoothing is applied to ACE-FTS, MIPAS, and NDACC vertical profiles. Smoothing is needed to account for differences between the vertical resolution of each instrument and differences in the dependence on a priori profiles. The smoothing operators use the TANSO-FTS a priori and averaging kernels in all cases. We present zonally averaged mean CH4 differences between each instrument and TANSO-FTS with and without smoothing, and we examine their information content, their sensitive altitude range, their correlation, their a priori dependence, and the

  16. Heat and mass transfer effects on the mixed convective flow of chemically reacting nanofluid past a moving/stationary vertical plate

    Directory of Open Access Journals (Sweden)

    B. Mahanthesh

    2016-03-01

    Full Text Available The problem of conjugate effects of heat and mass transfer over a moving/stationary vertical plate has been studied under the influence of applied magnetic field, thermal radiation, internal heat generation/absorption and first order chemical reaction. The fluid is assumed to be electrically conducting water based Cu-nanofluid. The Tiwari and Das model is used to model the nanofluid, whereas Rosseland approximation is used for thermal radiation effect. Unified closed form solutions are obtained for the governing equations using Laplace transform method. The velocity, temperature and concentration profiles are expressed graphically for different flow pertinent parameters. The physical quantities of engineering interest such as skin friction, Nusselt number and Sherwood number are also computed. The obtained analytical solutions satisfy all imposed initial and boundary conditions and they can be reduced to known previous results in some limiting cases. It is found that, by varying nanoparticle volume fraction, the flow and heat transfer characteristics could be controlled.

  17. Transmisión vertical del VIH: Comprendiendo el sentimiento de los padres por la técnica proyectiva HIV Vertical Transmission: Understanding the parents' feelings through the projective technique

    Directory of Open Access Journals (Sweden)

    Janie Maria de Almeida

    2009-06-01

    Full Text Available Estudio cualitativo realizado con padres de lactantes expuestos al VIH, cuya madre está inscrita en el Programa Transmisión Vertical Cero, Sorocaba, SP. El objetivo es identificar sentimientos relacionados con la fe religiosa de estos padres ante la indefinición del diagnóstico para el VIH del lactante. La investigación fue aprobada por un Comité de Ética en Investigación y siguió la Resolución 196/96. Para la recolección de datos se empleó la técnica proyectiva con montaje elaborada a partir de la pregunta "¿como ha sido para ustedes vivir el día-a-día esperando el resultado final de la prueba antiVIH del bebé?". La narrativa sobre su significado fue el paso siguiente. Se verificó que esta técnica fue eficiente para desencadenar el pensamiento de los participantes, para conducir y sustentar sus relatos. De los datos emergieron cinco temas, de los cuales destacamos religiosidad y espiritualidad que muestran que tienen fe y esperanza en un futuro saludable para el hijo expuesto al VIH.Qualitative study carried out with parents of newborn babies exposed to HIV whose mothers are registered at the Zero Vertical Transmission Program in Sorocaba, SP. The study aimed to identify feelings concerning the parents' religious faith while the baby seropositivity diagnosis for HIV is not defined yet. The research was approved by the Ethical Committee in Research according to Resolution 196/96. The projective technique was used for data collection in order to get answers for the following question: "how do you feel living your daily routine while you wait for your baby anti HIV test final result?" Speaking about its meaning was the next step. This technique has proved to be efficient in triggering the participants' thoughts and also in leading and supporting their reports. Five topics came up from the data collection; we highlighted two topics, religiosity and spirituality, which showed that having faith means being hopeful about the exposed

  18. Vertical Distribution of Water at Phoenix

    Science.gov (United States)

    Tamppari, L. K.; Lemmon, M. T.

    2011-01-01

    Phoenix results, combined with coordinated observations from the Mars Reconnaissance Orbiter of the Phoenix lander site, indicate that the water vapor is nonuniform (i.e., not well mixed) up to a calculated cloud condensation level. It is important to understand the mixing profile of water vapor because (a) the assumption of a well-mixed atmosphere up to a cloud condensation level is common in retrievals of column water abundances which are in turn used to understand the seasonal and interannual behavior of water, (b) there is a long history of observations and modeling that conclude both that water vapor is and is not well-mixed, and some studies indicate that the water vapor vertical mixing profile may, in fact, change with season and location, (c) the water vapor in the lowest part of the atmosphere is the reservoir that can exchange with the regolith and higher amounts may have an impact on the surface chemistry, and (d) greater water vapor abundances close to the surface may enhance surface exchange thereby reducing regional transport, which in turn has implications to the net transport of water vapor over seasonal and annual timescales.

  19. A Framework for Understanding Community Colleges' Organizational Capacity for Data Use: A Convergent Parallel Mixed Methods Study

    Science.gov (United States)

    Kerrigan, Monica Reid

    2014-01-01

    This convergent parallel design mixed methods case study of four community colleges explores the relationship between organizational capacity and implementation of data-driven decision making (DDDM). The article also illustrates purposive sampling using replication logic for cross-case analysis and the strengths and weaknesses of quantitizing…

  20. Understanding the Experiences of Women, Graduate Student Stress, and Lack of Marital/Social Support: A Mixed Method Inquiry

    Science.gov (United States)

    Williams-Tolliver, Sarah D.

    2010-01-01

    The purpose of this study was to explore how women attending graduate degree programs in public universities in Virginia were affected by such issues as stress and lack of marital/social support. Utilizing a mixed method approach for data collection, 23 participants completed demographic data, an essay response, and the PSS-10 Stress Scale; 8 were…

  1. Diel vertical migrat..

    African Journals Online (AJOL)

    2002-01-24

    Jan 24, 2002 ... Ringelberg 11964 The positively photo tactic reaction of Daphnia magna. Straus: A contribution to the understanding of diurnal vertical migration. Netherlands Journal of. Sea Research 2: 319—406. Ringelberg J 1980 Introductory remarks: causal and teleological aspects of diurnal migration. ~ In: Kerfoot,.

  2. Vertical Implementation

    NARCIS (Netherlands)

    Rensink, Arend; Gorrieri, Roberto

    2001-01-01

    We investigate criteria to relate specifications and implementations belonging to conceptually different levels of abstraction. For this purpose, we introduce the generic concept of a vertical implementation relation, which is a family of binary relations indexed by a refinement function that maps

  3. Understanding low uptake of contraceptives in resource-limited settings: a mixed-methods study in rural Burundi

    OpenAIRE

    Ndayizigiye, M.; Fawzi, M. C. Smith; Lively, C. Thompson; Ware, N.C.

    2017-01-01

    Background: Family planning can reduce deaths, improve health, and facilitate economic development in resource-limited settings. Yet, modern contraceptive methods are often underused. This mixed-methods study, conducted in rural Burundi, sought to explain low uptake of contraceptives by identifying utilization barriers. Results may inform development of family planning interventions in Burundi and elsewhere. Methods: We investigated uptake of contraceptives among women of reproductive age in ...

  4. An Approach to Understanding Cohesive Slurry Settling, Mobilization, and Hydrogen Gas Retention in Pulsed Jet Mixed Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Wells, Beric E.; Fort, James A.; Meyer, Perry A.

    2009-05-22

    The Hanford Waste Treatment and Immobilization Plant (WTP) is being designed and built to pretreat and vitrify a large portion of the waste in Hanford’s 177 underground waste storage tanks. Numerous process vessels will hold waste at various stages in the WTP. Some of these vessels have mixing-system requirements to maintain conditions where the accumulation of hydrogen gas stays below acceptable limits, and the mixing within the vessels is sufficient to release hydrogen gas under normal conditions and during off-normal events. Some of the WTP process streams are slurries of solid particles suspended in Newtonian fluids that behave as non-Newtonian slurries, such as Bingham yield-stress fluids. When these slurries are contained in the process vessels, the particles can settle and become progressively more concentrated toward the bottom of the vessels, depending on the effectiveness of the mixing system. One limiting behavior is a settled layer beneath a particle-free liquid layer. The settled layer, or any region with sufficiently high solids concentration, will exhibit non-Newtonian rheology where it is possible for the settled slurry to behave as a soft solid with a yield stress. In this report, these slurries are described as settling cohesive slurries.

  5. Understanding the effects of bulk mixing on the determination of the affinity index: consequences for process operation and design.

    Science.gov (United States)

    Arnaldos, Marina; Rehman, Usman; Naessens, Wouter; Amerlinck, Youri; Nopens, Ingmar

    2018-02-01

    The main objective of this study is to demonstrate the importance of mixing conditions as a source of inconsistencies between half-saturation indices in comparable systems (e.g. conventional activated sludge, membrane bioreactor) when operated at different conditions or different scales. As proof-of-principle, an exemplary system consisting of the second vessel of a hybrid respirometer has been studied. The system has been modeled both using an integrated computational fluid dynamics (CFD)-biokinetic model (assumed to represent the physical system) and a tanks-in-series, completely stirred tank reactor biokinetic model (representing the applied model). The results show that different mixing conditions cause deviations in the half-saturation indices calculated when matching the applied model to the physical system performance. Additionally, sensor location has been shown to impact the calculation of half-saturation indices in the respirometric system. This will only become more pronounced at larger scales. Thus, mixing conditions clearly affect operation and design of wastewater treatment reactors operated at low substrate concentrations. Both operation and design can be improved with the development and application of integrated CFD-biokinetic or compartmental models.

  6. Spectral analysis of the efficiency of vertical mixing in the deep ocean due to interaction of tidal currents with a ridge running down a continental slope

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimov, Ranis N.; Tartakovsky, Alexandre M.

    2014-10-29

    Efficiency of mixing, resulting from the reflection of an internal wave field imposed on the oscillatory background flow with a three-dimensional bottom topography, is investigated using a linear approximation. The radiating wave field is associated with the spectrum of the linear model, which consists of those mode numbers n and slope values α, for which the solution represents the internal waves of frequencies ω = nω0 radiating upwrad of the topography, where ω0 is the fundamental frequency at which internal waves are generated at the topography. The effects of the bottom topography and the earth’s rotation on the spectrum is analyzed analytically and numerically in the vicinity of the critical slope, which is a slope with the same angle to the horizontal as the internal wave characteristic. In this notation, θ is latitude, f is the Coriolis parameter and N is the buoyancy frequency, which is assumed to be a constant, which corresponds to the uniform stratification.

  7. Understanding the Effect of Stratification on Vertical and Temporal Heterogenieties of Cyanobacteria Blooms in Lakes Using a Long Term in-situ Monitoring Station

    Science.gov (United States)

    Wilkinson, A.; Guala, M.; Hondzo, M.

    2017-12-01

    Harmful Algal Blooms (HAB) are made up of potentially toxic freshwater microorganisms called cyanobacteria, because of this they are a ecological and public health hazard. The occurrences of toxic HAB are unpredictable and highly spatially and temporary variable in freshwater ecosystems. To study the abiotic drivers for toxic HAB, a floating research station has been deployed in a hyper-eutrophic lake in Madison Lake, Minnesota, from June-October 2016. This research station provides full depth water quality (hourly) and meteorological monitoring (5 minutes). Water quality monitoring is performed by an autonomously traversed water quality sonde that provides chemical, physical and biological measurements; including phycocyanin, a photosynthetic pigment distinct to cyanobacteria. A bloom of cyanobacteria recorded in the epiliminion in mid-July was driven by prolonged strong thermal stratification in the water column, high surface water temperatures and high phosphate concentrations in the epiliminion. The high biovolume (BV) persisted until late September and was sustained below the surface after stratification weakened, when the thermocline did not confine cyanobacteria-rich layers any more, and cyanobacteria vertical heterogeneities decayed in the water column. High correlations among BV stratification, surface water temperature, and stratification stability informed the development of a quantitative relationship to determine how BV heterogeneities vary with thermal structure in the water column. The BV heterogeneity decreased with thermal stratification stability and surface water temperature, and the dynamic lake stability described by the Lake Number. Finally the location of maximum BV accumulation showed diurnal patterns ie. BV peaks were observed at 1 m depth during the day and deeper layers during the night, which followed patterns in light penetration and thermocline depth. These findings capture cyanobacteria vertical and temporal heterogeneities on a on

  8. Fine Root Growth and Vertical Distribution in Response to Elevated CO2, Warming and Drought in a Mixed Heathland–Grassland

    DEFF Research Database (Denmark)

    Arndal, Marie Frost; Tolver, Anders; Larsen, Klaus Steenberg

    2018-01-01

    Belowground plant responses have received much less attention in climate change experiments than aboveground plant responses, thus hampering a holistic understanding of climate change effects on plants and ecosystems. In addition, responses of plant roots to climate change have mostly been studied...... production from ingrowth cores, but decreased fine root number and length in minirhizotrons, whereas there were no significant main effects of drought. Across all treatments and soil depths, CO2 stimulated both the total fine root length (+44%) and the number of roots observed (+39%), with highest relative...

  9. Experimental study on the effects of channel gap size on mixed convection heat transfer characteristics in vertical rectangular channels heated from both sides

    International Nuclear Information System (INIS)

    Sudo, Y.; Kaminaga, M.

    1990-01-01

    The effects of channel gap size on mixed forced and free convective heat transfer characteristics were experimentally investigated for water flowing near atmospheric pressure in a 750 mm long and 50 mm wide channel heated from both sides. The channel gap sizes investigated were 2.5, 6, 18 and 50 mm. Experiments were carried out for both aiding and opposing forced convective flows with a Reynolds number Re x of 4x10 to 6x10 6 and a Grashof number Gr x of 2x10 4 to 6x10 11 , where the distance x from the inlet of the channel is adopted as the characteristic length in Re x and Gr x . As for the results, the following were revealed for the parameters ranges investigated in this study. (1) When the dimensionless parameter, Gr x /Re x 21/8 Pr 1/2 is less than 10 -4 , the flow shows the nature of forced convective heat transfer for a channel with any channel gap size in both aiding and opposing flows. (2) When Gr x /Re x 21/8 Pr 1/2 is larger than 10 -2 , the flow shows the nature of free convective heat transfer for a channel with any channel gap size in both aiding and opposing flows. (3) When Gr x /Re x 21/8 Pr 1/2 is between 10 -4 and 10 -2 for the channel with a channel gap size equal to or larger than 6 mm, the heat transfer coefficients in both aiding and opposing flows become, on the average, higher than those predicted by the previous correlations for either the pure turbulent forced convection or the pure free convection, and can be expressed in simple forms with a combination of Gr x /Re x 21/8 Pr 1/2 and the previous correlation for either the pure turbulent forced convection or the free convection along a flat plate. (4) When Gr x /Re x 21/8 Pr 1/2 is between 10 -4 and 10 -2 for the channel with a channel gap size of 2.5 mm, the heat transfer coefficients in both aiding and opposing flows also become, on the average, higher than those predicted by the previous correlations for either the pure turbulent forced convection or the pure free convection. (orig./GL)

  10. Understanding low uptake of contraceptives in resource-limited settings: a mixed-methods study in rural Burundi.

    Science.gov (United States)

    Ndayizigiye, M; Fawzi, M C Smith; Lively, C Thompson; Ware, N C

    2017-03-15

    Family planning can reduce deaths, improve health, and facilitate economic development in resource-limited settings. Yet, modern contraceptive methods are often underused. This mixed-methods study, conducted in rural Burundi, sought to explain low uptake of contraceptives by identifying utilization barriers. Results may inform development of family planning interventions in Burundi and elsewhere. We investigated uptake of contraceptives among women of reproductive age in two rural districts of Burundi, using an explanatory sequential, mixed-methods research design. We first assessed availability and utilization rates of modern contraceptives through a facility-based survey in 39 health clinics. Barriers to uptake of contraceptives were then explored through qualitative interviews (N = 10) and focus groups (N = 7). Contraceptives were generally available in the 39 clinics studied, yet uptake of family planning averaged only 2.96%. Greater uptake was positively associated with the number of health professionals engaged and trained in family planning service provision, and with the number of different types of contraceptives available. Four uptake barriers were identified: (1) lack of providers to administer contraception, (2) lack of fit between available and preferred contraceptive methods, (3) a climate of fear surrounding contraceptive use, and (4) provider refusal to offer family planning services. Where resources are scarce, availability of modern contraceptives alone will likely not ensure uptake. Interventions addressing multiple uptake barriers simultaneously have the greatest chance of success. In rural Burundi, examples are community distribution of contraceptive methods, public information campaigns, improved training for health professionals and community health workers, and strengthening of the health infrastructure.

  11. Understanding Chemical Equilibrium: The Role of Gas Phases and Mixing Contributions in the Minimum of Free Energy Plots

    Science.gov (United States)

    Tomba, J. Pablo

    2017-01-01

    The use of free energy plots to understand the concept of thermodynamic equilibrium has been shown to be of great pedagogical value in materials science. Although chemical equilibrium is also amenable to this kind of analysis, it is not part of the agenda of materials science textbooks. Something similar is found in chemistry branches, where free…

  12. Effect of the 5E Model on Prospective Teachers' Conceptual Understanding of Diffusion and Osmosis: A Mixed Method Approach

    Science.gov (United States)

    Artun, Huseyin; Costu, Bayram

    2013-01-01

    The aim of this study was to explore a group of prospective primary teachers' conceptual understanding of diffusion and osmosis as they implemented a 5E constructivist model and related materials in a science methods course. Fifty prospective primary teachers' ideas were elicited using a pre- and post-test and delayed post-test survey consisting…

  13. An Exploratory Mixed Method Assessment of Low Income, Pregnant Hispanic Women's Understanding of Gestational Diabetes and Dietary Change

    Science.gov (United States)

    Rhoads-Baeza, Maria Elena; Reis, Janet

    2012-01-01

    Objective: To describe and assess low income, healthy, pregnant Hispanic women's understanding of gestational diabetes (GDM) and willingness to change aspects of their diet. Design: One-on-one, in-person interviews conducted in Spanish with 94 women (primarily Mexican). Setting: Federal Qualified Community Health Center's prenatal clinic. Method:…

  14. Motivations, barriers and ethical understandings of healthcare student volunteers on a medical service trip: a mixed methods study.

    Science.gov (United States)

    Rovers, John; Japs, Kelsey; Truong, Erica; Shah, Yogesh

    2016-03-22

    The motivation to volunteer on a medical service trip (MST) may involve more than a simple desire for philanthropy. Some volunteers may be motivated by an intrinsic interest in volunteering in which the context of the volunteer activity is less important. Others may volunteer because the context of their volunteering is more important than their intrinsic interest in volunteering. Furthermore, MSTs may pose a variety of ethical problems that volunteers should consider prior to engaging in a trip. This study evaluated the motivations and barriers for graduate health care students volunteering for an MST to either the Dominican Republic or Mississippi. Volunteers' understanding of some of the ethical issues associated with MSTs was also assessed. Thirty-five graduate health professions students who volunteered on an MST were asked to complete an online survey. Students' motivations and barriers for volunteering were assessed using a 5-point Likert scale and Fisher's exact test. Ethical understanding of issues in volunteering was assessed using thematic analysis. Students' motivations for volunteering appeared to be related to the medical context of their service more than an inherent desire for volunteer work. Significant differences were seen in motivations and barriers for some student groups, especially those whose volunteer work had less opportunity for clinical service. Thematic analysis revealed two major themes and suggested that students had an empirical understanding that volunteer work could have both positive and negative effects. An understanding of students' motivations for volunteering on an MST may allow faculty to design trips with activities that effectively address student motivations. Although students had a basic understanding of some of the ethical issues involved, they had not considered the impact of a service group on the in-country partners they work with.

  15. Understanding Usage of a Hybrid Website and Smartphone App for Weight Management: A Mixed-Methods Study

    Science.gov (United States)

    Hargood, Charlie; Lin, Sharon Xiaowen; Dennison, Laura; Joseph, Judith; Hughes, Stephanie; Michaelides, Danius T; Johnston, Derek; Johnston, Marie; Michie, Susan; Little, Paul; Smith, Peter WF; Weal, Mark J; Yardley, Lucy

    2014-01-01

    Background Advancements in mobile phone technology offer huge potential for enhancing the timely delivery of health behavior change interventions. The development of smartphone-based health interventions (apps) is a rapidly growing field of research, yet there have been few longitudinal examinations of how people experience and use these apps within their day-to-day routines, particularly within the context of a hybrid Web- and app-based intervention. Objective This study used an in-depth mixed-methods design to examine individual variation in (1) impact on self-reported goal engagement (ie, motivation, self-efficacy, awareness, effort, achievement) of access to a weight management app (POWeR Tracker) when provided alongside a Web-based weight management intervention (POWeR) and (2) usage and views of POWeR Tracker. Methods Thirteen adults were provided access to POWeR and were monitored over a 4-week period. Access to POWeR Tracker was provided in 2 alternate weeks (ie, weeks 1 and 3 or weeks 2 and 4). Participants’ goal engagement was measured daily via self-report. Mixed effects models were used to examine change in goal engagement between the weeks when POWeR Tracker was and was not available and whether the extent of change in goal engagement varied between individual participants. Usage of POWeR and POWeR Tracker was automatically recorded for each participant. Telephone interviews were conducted and analyzed using inductive thematic analysis to further explore participants’ experiences using POWeR and POWeR Tracker. Results Access to POWeR Tracker was associated with a significant increase in participants’ awareness of their eating (β1=0.31, P=.04) and physical activity goals (β1=0.28, P=.03). The level of increase varied between individual participants. Usage data showed that participants used the POWeR website for similar amounts of time during the weeks when POWeR Tracker was (mean 29 minutes, SD 31 minutes) and was not available (mean 27 minutes

  16. Understanding usage of a hybrid website and smartphone app for weight management: a mixed-methods study.

    Science.gov (United States)

    Morrison, Leanne G; Hargood, Charlie; Lin, Sharon Xiaowen; Dennison, Laura; Joseph, Judith; Hughes, Stephanie; Michaelides, Danius T; Johnston, Derek; Johnston, Marie; Michie, Susan; Little, Paul; Smith, Peter Wf; Weal, Mark J; Yardley, Lucy

    2014-10-22

    Advancements in mobile phone technology offer huge potential for enhancing the timely delivery of health behavior change interventions. The development of smartphone-based health interventions (apps) is a rapidly growing field of research, yet there have been few longitudinal examinations of how people experience and use these apps within their day-to-day routines, particularly within the context of a hybrid Web- and app-based intervention. This study used an in-depth mixed-methods design to examine individual variation in (1) impact on self-reported goal engagement (ie, motivation, self-efficacy, awareness, effort, achievement) of access to a weight management app (POWeR Tracker) when provided alongside a Web-based weight management intervention (POWeR) and (2) usage and views of POWeR Tracker. Thirteen adults were provided access to POWeR and were monitored over a 4-week period. Access to POWeR Tracker was provided in 2 alternate weeks (ie, weeks 1 and 3 or weeks 2 and 4). Participants' goal engagement was measured daily via self-report. Mixed effects models were used to examine change in goal engagement between the weeks when POWeR Tracker was and was not available and whether the extent of change in goal engagement varied between individual participants. Usage of POWeR and POWeR Tracker was automatically recorded for each participant. Telephone interviews were conducted and analyzed using inductive thematic analysis to further explore participants' experiences using POWeR and POWeR Tracker. Access to POWeR Tracker was associated with a significant increase in participants' awareness of their eating (β1=0.31, P=.04) and physical activity goals (β1=0.28, P=.03). The level of increase varied between individual participants. Usage data showed that participants used the POWeR website for similar amounts of time during the weeks when POWeR Tracker was (mean 29 minutes, SD 31 minutes) and was not available (mean 27 minutes, SD 33 minutes). POWeR Tracker was mostly

  17. Understanding the effects of time on collaborative learning processes in problem based learning: a mixed methods study.

    Science.gov (United States)

    Hommes, J; Van den Bossche, P; de Grave, W; Bos, G; Schuwirth, L; Scherpbier, A

    2014-10-01

    Little is known how time influences collaborative learning groups in medical education. Therefore a thorough exploration of the development of learning processes over time was undertaken in an undergraduate PBL curriculum over 18 months. A mixed-methods triangulation design was used. First, the quantitative study measured how various learning processes developed within and over three periods in the first 1,5 study years of an undergraduate curriculum. Next, a qualitative study using semi-structured individual interviews focused on detailed development of group processes driving collaborative learning during one period in seven tutorial groups. The hierarchic multilevel analyses of the quantitative data showed that a varying combination of group processes developed within and over the three observed periods. The qualitative study illustrated development in psychological safety, interdependence, potency, group learning behaviour, social and task cohesion. Two new processes emerged: 'transactive memory' and 'convergence in mental models'. The results indicate that groups are dynamic social systems with numerous contextual influences. Future research should thus include time as an important influence on collaborative learning. Practical implications are discussed.

  18. Understanding Uncertainties in the Economic Feasibility of Transportation Fuel Production using Biomass Gasification and Mixed Alcohol Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Longwen [Department of Mechanical Engineering, Iowa State University, Ames IA 50010 USA; Li, Boyan [Department of Mechanical Engineering, Iowa State University, Ames IA 50010 USA; Dang, Qi [Department of Mechanical Engineering, Iowa State University, Ames IA 50010 USA; Bioeconomy Institute, Iowa State University, Ames IA 50012 USA; Jones, Susanne [Pacific Northwest National Laboratory, Richland WA 99352 USA; Brown, Robert [Department of Mechanical Engineering, Iowa State University, Ames IA 50010 USA; Bioeconomy Institute, Iowa State University, Ames IA 50012 USA; Wright, Mark M. [Department of Mechanical Engineering, Iowa State University, Ames IA 50010 USA; Bioeconomy Institute, Iowa State University, Ames IA 50012 USA

    2016-01-29

    This analysis evaluates uncertainties of previously conducted techno-economic analysis of transportation fuel production via biomass gasification and mixed alcohol synthesis. Two scenarios are considered: a state-of-technology scenario utilizing existing technologies and a target scenario representing future advancements in related technologies. Uncertainties of more than ten parameters are investigated, including feedstock price, internal rate of return (IRR), etc. Historical price data of these parameters are fitted with the most appropriate distribution and datasets are generated for each parameter accordingly. These data sets are then utilized to run a Monte-Carlo simulation. The results yield minimum fuel selling prices of $7.02/gal with a standard deviation of 0.49 for the state-of-technology scenario and $4.33/gal with a standard deviation of 0.42 for the target scenario respectively. Feedstock price and IRR have significant impact on the minimum fuel selling price in both scenarios. These findings are indicative of the reduction in biofuel cost and uncertainty achievable with increasing technology maturity.

  19. Understanding variations in the use of hypofractionated radiotherapy and its specific indications for breast cancer: A mixed-methods study.

    Science.gov (United States)

    Prades, Joan; Algara, Manel; Espinàs, Josep A; Farrús, Blanca; Arenas, Meritxell; Reyes, Victoria; García-Reglero, Virginia; Cambra, Maria Josep; Rubio, Esther; Anglada, Lluis; Eraso, Arantxa; Pedro, Agustí; Fuentes-Raspall, Maria J; Tuset, Victòria; Solà, Judit; Borras, Josep M

    2017-04-01

    Radiation oncology guidelines favour hypofractionated whole-breast radiotherapy (HWBRT) over more conventional schemes in the conservative treatment of breast cancer, but its adoption still varies in clinical practice. This study assessed the patterns of HWBRT adoption in Catalonia (Spain). We used a mixed-methods approach based on an explanatory sequential design, first collecting and analysing quantitative data on HWBRT use (>2.5Gy per fraction) in 11 public radiotherapy centres (2005-2015) and then performing 25 semi-structured interviews with all department heads and reference radiation oncologist/s. Of the 34,859 patients fulfiling the study criteria over the study period, just 12% were hypofractionated, reaching a percentage of 29% in 2015 (p<0.001). Our analysis showed a narrowing age gap between patients receiving conventional fractionation and hypofractionation in centres leading adoption. However, there were important differences in clinicians' interpretation of evidence (e.g. regarding the perceived risk of long-term toxicity) and selection of patients for specific indications, both within and between departments. Differences observed in the rate of adoption of HWBRT could not be tackled only using a rational, evidence-based approach. Factors related to the management of radiotherapy departments play a major role in the diffusion of therapeutic strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Cambios en la viabilidad de dos bacterias marinas antárticas expuestas a la radiación solar en la columna de agua: influencia de la mezcla vertical Changes in viability of two Antarctic marine bacteria exposed to solar radiation in the water column: influence of vertical mixing

    Directory of Open Access Journals (Sweden)

    E. A. Hernández

    2007-09-01

    Full Text Available Se estudió el efecto de la radiación ultravioleta (RUV sobre dos cepas bacterianas marinas antárticas (UVps y UVvi en la columna de agua de la caleta Potter (Shetland del Sur, Antártida. Frascos de cuarzo con las cepas en estudio fueron expuestos a la radiación solar en superficie, a 1 m y a 3 m de profundidad. Se realizaron ensayos con exposición directa y con filtros interferenciales que discriminaron la radiación UVA y la UVB. En otros ensayos se simuló una mezcla vertical de 4 m/h. Ambas cepas mostraron una disminución significativa del número de unidades formadoras de colonias, tanto en superficie como a 1 m de profundidad, luego de exponerlas a dosis superficiales de UVB de 8,4 kJ m-2. El estudio con filtros interferenciales mostró una disminución significativa de la viabilidad en ambos tratamientos UV en superficie y a 1 m. La cepa UVps mostró mayor sensibilidad a la UVB que a la UVA. La mezcla vertical amortiguó el daño causado por la UVB cuando la dosis en superficie fue de 4,8 kJ m-2. Este efecto amortiguador no se observó cuando la dosis en superficie fue de 7,7 kJ m-2. Estos resultados muestran que el efecto negativo de la RUV sobre el bacterioplancton sería particularmente importante en el primer metro de profundidad de las aguas costeras antárticas con abundante material particulado en suspensión.The effect of UV radiation on two Antarctic marine bacterial strains (UVps and UVvi was studied in the water column of Potter Cove (South Shetland, Antarctica. Quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. Assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between UVA and UVB, were performed. In other assays, a vertical mixing of 4 m/h was simulated. Both strains showed a significant decrease in viability (expressed as colony - forming units when exposed to a surface

  1. Use of Correlation Relationships to Enhance Understanding of Pedogenic Processes and Use Potential of Vertisols and Vertic Inceptisols of the Bale Mountain Area of Ethiopia

    Directory of Open Access Journals (Sweden)

    Verdoodt, A.

    2009-01-01

    Full Text Available Five Vertisols and two Vertic Inceptisols developed from basalt and alluvial materials were characterized for physical and chemical properties. Correlative statistical relationships were established among physical and chemical properties including cation exchange capacity (CEC, percent total clay, electrical conductivity (EC, base saturation % (BS, pH-H2O, pH-KCl, CaCO3 equivalent, organic carbon (OC, total nitrogen (TN, P-Bray and P-Olsen. Correlative relationships were established among parameters for all horizons of the soils studied as well as among parameters within individual horizons. P-Olsen was highly correlated with OC and TN; simple coefficients of determination (r2 were 0.81 and 0.69, respectively. CaCO3 was highly correlated with pH-H2O and pH-KCl; r2 values were 0.68 and 0.60, respectively. Similar correlations were obtained for pHKCl vs pH-H2O and pH-KCl vs EC, with r2 values of 0.92 and 0.70, respectively. Total nitrogen was also very highly correlated with OC (r2= 0.88. Base saturation was highly correlated with pH-KCl and pH-H2O giving r2 values of 0.62 and 0.64, respectively. When correlative relationships were carried out among parameters within individual horizons very high correlation coefficients were obtained for OC vs TN (r= 0.98 - 1.00, OC vs P-Olsen (r= 0.96 - 0.99, BS vs pH-KCl (r= 0.82 - 1.00, BS vs pH-H2O (r= 0.86 - 1.00. Most of the simple correlation coefficients obtained for EC with pH-KCl and pH-H2O were > 0.81. High correlation coefficients (0.80 - 1.00 were obtained for % clay vs total CEC for most soils studied. Regression relationships developed constitute useful predictive indices for estimating agronomic properties from existing physical and chemical data and soil survey reports of the Bale Mountain area of Ethiopia. This study has demonstrated that statistical correlation can be used to cross-check the quality of analytical data both among horizons of different soil profiles and within individual soil

  2. Understanding the Essential Meaning of Measured Changes in Weight and Body Composition Among Women During and After Adjuvant Treatment for Breast Cancer: A Mixed-Methods Study.

    Science.gov (United States)

    Pedersen, Birgith; Groenkjaer, Mette; Falkmer, Ursula; Delmar, Charlotte

    Changes in weight and body composition among women during and after adjuvant antineoplastic treatment for breast cancer may influence long-term survival and quality of life. Research on factual weight changes is diverse and contrasting, and their influence on women's perception of body and self seems to be insufficiently explored. The aim of this study was to expand the understanding of the association between changes in weight and body composition and the women's perception of body and selves. A mixed-methods research design was used. Data consisted of weight and body composition measures from 95 women with breast cancer during 18 months past surgery. Twelve women from this cohort were interviewed individually at 12 months. Linear mixed model and logistic regression were used to estimate changes of repeated measures and odds ratio. Interviews were analyzed guided by existential phenomenology. Joint displays and integrative mixed-methods interpretation demonstrated that even small weight gains, extended waist, and weight loss were associated with fearing recurrence of breast cancer. Perceiving an ambiguous transforming body, the women moved between a unified body subject and the body as an object dissociated in "I" and "it" while fighting against or accepting the body changes. Integrating findings demonstrated that factual weight changes do not correspond with the perceived changes and may trigger existential threats. Transition to a new habitual body demand health practitioners to enter a joint narrative work to reveal how the changes impact on the women's body and self-perception independent of how they are displayed quantitatively.

  3. A Pilot Study Using Mixed GPS/Narrative Interview Methods to Understand Geospatial Behavior in Homeless Populations.

    Science.gov (United States)

    North, Carol S; Wohlford, Sarah E; Dean, Denis J; Black, Melissa; Balfour, Margaret E; Petrovich, James C; Downs, Dana L; Pollio, David E

    2017-08-01

    Tracking the movements of homeless populations presents methodological difficulties, but understanding their movements in space and time is needed to inform optimal placement of services. This pilot study developed, tested, and refined methods to apply global positioning systems (GPS) technology paired with individual narratives to chronicle the movements of homeless populations. Detail of methods development and difficulties encountered and addressed, and geospatial findings are provided. A pilot sample of 29 adults was recruited from a low-demand homeless shelter in the downtown area of Fort Worth, Texas. Pre- and post-deployment interviews provided participant characteristics and planned and retrospectively-reported travels. Only one of the first eight deployments returned with sufficient usable data. Ultimately 19 participants returned the GPS device with >20 h of usable data. Protocol adjustments addressing methodological difficulties achieved 81 % of subsequent participants returning with sufficient usable data. This study established methods and demonstrated feasibility for tracking homeless population travels.

  4. Vertically resolved characteristics of air pollution during two severe winter haze episodes in urban Beijing, China

    Science.gov (United States)

    Wang, Qingqing; Sun, Yele; Xu, Weiqi; Du, Wei; Zhou, Libo; Tang, Guiqian; Chen, Chen; Cheng, Xueling; Zhao, Xiujuan; Ji, Dongsheng; Han, Tingting; Wang, Zhe; Li, Jie; Wang, Zifa

    2018-02-01

    We conducted the first real-time continuous vertical measurements of particle extinction (bext), gaseous NO2, and black carbon (BC) from ground level to 260 m during two severe winter haze episodes at an urban site in Beijing, China. Our results illustrated four distinct types of vertical profiles: (1) uniform vertical distributions (37 % of the time) with vertical differences less than 5 %, (2) higher values at lower altitudes (29 %), (3) higher values at higher altitudes (16 %), and (4) significant decreases at the heights of ˜ 100-150 m (14 %). Further analysis demonstrated that vertical convection as indicated by mixing layer height, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles. Particularly, the formation of type 4 was strongly associated with the stratified layer that was formed due to the interactions of different air masses and temperature inversions. Aerosol composition was substantially different below and above the transition heights with ˜ 20-30 % higher contributions of local sources (e.g., biomass burning and cooking) at lower altitudes. A more detailed evolution of vertical profiles and their relationship with the changes in source emissions, mixing layer height, and aerosol chemistry was illustrated by a case study. BC showed overall similar vertical profiles as those of bext (R2 = 0.92 and 0.69 in November and January, respectively). While NO2 was correlated with bext for most of the time, the vertical profiles of bext / NO2 varied differently for different profiles, indicating the impact of chemical transformation on vertical profiles. Our results also showed that more comprehensive vertical measurements (e.g., more aerosol and gaseous species) at higher altitudes in the megacities are needed for a better understanding of the formation mechanisms and evolution of severe haze episodes in China.

  5. Vertical allometry: fact or fiction?

    Science.gov (United States)

    Mahmood, Iftekhar; Boxenbaum, Harold

    2014-04-01

    In pharmacokinetics, vertical allometry is referred to the clearance of a drug when the predicted human clearance is substantially higher than the observed human clearance. Vertical allometry was initially reported for diazepam based on a 33-fold higher human predicted clearance than the observed human clearance. In recent years, it has been found that many other drugs besides diazepam, can be classified as drugs which exhibit vertical allometry. Over the years, many questions regarding vertical allometry have been raised. For example, (1) How to define and identify the vertical allometry? (2) How much difference should be between predicted and observed human clearance values before a drug could be declared 'a drug which follows vertical allometry'? (3) If somehow one can identify vertical allometry from animal data, how this information can be used for reasonably accurate prediction of clearance in humans? This report attempts to answer the aforementioned questions. The concept of vertical allometry at this time remains complex and obscure but with more extensive works one can have better understanding of 'vertical allometry'. Published by Elsevier Inc.

  6. Understanding barriers to fruit and vegetable intake in the Australian Longitudinal Study of Indigenous Children: a mixed-methods approach.

    Science.gov (United States)

    Thurber, Katherine Ann; Banwell, Cathy; Neeman, Teresa; Dobbins, Timothy; Pescud, Melanie; Lovett, Raymond; Banks, Emily

    2017-04-01

    To identify barriers to fruit and vegetable intake for Indigenous Australian children and quantify factors related to these barriers, to help understand why children do not meet recommendations for fruit and vegetable intake. We examined factors related to carer-reported barriers using multilevel Poisson models (robust variance); a key informant focus group guided our interpretation of findings. Eleven diverse sites across Australia. Australian Indigenous children and their carers (N 1230) participating in the Longitudinal Study of Indigenous Children. Almost half (45 %; n 555/1230) of carers reported barriers to their children's fruit and vegetable intake. Dislike of fruit and vegetables was the most common barrier, reported by 32·9 % of carers; however, we identified few factors associated with dislike. Carers were more than ten times less likely to report barriers to accessing fruit and vegetables if they lived large cities v. very remote areas. Within urban and inner regional areas, child and carer well-being, financial security, suitable housing and community cohesion promoted access to fruit and vegetables. In this national Indigenous Australian sample, almost half of carers faced barriers to providing their children with a healthy diet. Both remote/outer regional carers and disadvantaged urban/inner regional carers faced problems accessing fruit and vegetables for their children. Where vegetables were accessible, children's dislike was a substantial barrier. Nutrition promotion must address the broader family, community, environmental and cultural contexts that impact nutrition, and should draw on the strengths of Indigenous families and communities.

  7. Understanding Private Sector Antimalarial Distribution Chains: A Cross-Sectional Mixed Methods Study in Six Malaria-Endemic Countries

    Science.gov (United States)

    Palafox, Benjamin; Patouillard, Edith; Tougher, Sarah; Goodman, Catherine; Hanson, Kara; Kleinschmidt, Immo; Rueda, Sergio Torres; Kiefer, Sabine; O’Connell, Kathryn A.; Zinsou, Cyprien; Phok, Sochea; Akulayi, Louis; Arogundade, Ekundayo; Buyungo, Peter; Mpasela, Felton; Chavasse, Desmond

    2014-01-01

    antimalarial supply sources. Conclusions The structure and characteristics of antimalarial distribution chains vary across countries; therefore, understanding the wholesalers that comprise them should inform efforts aiming to improve access to quality treatment through the private sector. PMID:24699934

  8. Understanding private sector antimalarial distribution chains: a cross-sectional mixed methods study in six malaria-endemic countries.

    Directory of Open Access Journals (Sweden)

    Benjamin Palafox

    .The structure and characteristics of antimalarial distribution chains vary across countries; therefore, understanding the wholesalers that comprise them should inform efforts aiming to improve access to quality treatment through the private sector.

  9. The stable isotopic composition of water vapour above Corsica during the HyMeX SOP1 campaign: insight into vertical mixing processes from lower-tropospheric survey flights

    Science.gov (United States)

    Sodemann, Harald; Aemisegger, Franziska; Pfahl, Stephan; Bitter, Mark; Corsmeier, Ulrich; Feuerle, Thomas; Graf, Pascal; Hankers, Rolf; Hsiao, Gregor; Schulz, Helmut; Wieser, Andreas; Wernli, Heini

    2017-05-01

    Stable isotopes of water vapour are powerful indicators of meteorological processes on a broad range of scales, reflecting evaporation, condensation, and air mass mixing processes. With the recent advent of fast laser-based spectroscopic methods, it has become possible to measure the stable isotopic composition of atmospheric water vapour in situ at a high temporal resolution. Here we present results from such comprehensive airborne spectroscopic isotope measurements in water vapour over the western Mediterranean at a high spatial and temporal resolution. Measurements have been acquired by a customized Picarro L2130-i cavity-ring down spectrometer deployed onboard the Dornier 128 D-IBUF aircraft together with a meteorological flux measurement package during the HyMeX SOP1 (Hydrological cycle in Mediterranean Experiment special observation period 1) field campaign in Corsica, France, during September and October 2012. Taking into account memory effects of the air inlet pipe, the typical time resolution of the measurements was about 15-30 s, resulting in an average horizontal resolution of about 1-2 km. Cross-calibration of the water vapour measurements from all humidity sensors showed good agreement under most flight conditions but the most turbulent ones. In total 21 successful stable isotope flights with 59 flight hours have been performed. Our data provide quasi-climatological autumn average conditions and vertical profiles of the stable isotope parameters δD, δ18O, and d-excess during the study period. A d-excess minimum in the overall average profile is reached in the region of the boundary-layer top, possibly caused by precipitation evaporation. This minimum is bracketed by higher d-excess values near the surface caused by non-equilibrium fractionation, and a maximum above the boundary layer related to the increasing d-excess in very depleted and dry high-altitude air masses. Repeated flights along the same pattern reveal pronounced day-to-day variability

  10. Understanding Older Adult's Technology Adoption and Withdrawal for Elderly Care and Education: Mixed Method Analysis from National Survey.

    Science.gov (United States)

    Chiu, Ching-Ju; Liu, Chia-Wen

    2017-11-03

    affected by health barriers (26.0%, 39/150 vs 15.9%, 22/138; P=.004) and anthropic factors or accidental barriers (7.3%, 11/150 vs 2.9%, 4/138; P=.02). Our findings that the need to keep up with the world associated with Internet adoption, and gender differences in reasons behind Internet withdrawal, such that women reported more health and anthropic factors or accidental barriers than man, may provide a new perspective that help health educators understand strategies that encourage older adults to keep learning, an important component of active aging. ©Ching-Ju Chiu, Chia-Wen Liu. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 03.11.2017.

  11. Establishment of a Subsidence Superstation in the Mississippi Delta: Integrating sediment core, SET, GPS and vertical strainmeter data to understand subsidence

    Science.gov (United States)

    Steckler, M. S.; Allison, M. A.; Bridgeman, J.; Dixon, T. H.; Hatfield, W.; A Karegar, M.; Tornqvist, T. E.; Zumberge, M. A.; Wyatt, F. K.

    2017-12-01

    There is a great need for coordinated efforts to monitor and better understand subsidence rates in low-elevation coastal zones by integrating different, complementary techniques at carefully selected sites. We present recent efforts to establish a subsidence superstation in the Mississippi Delta. The site is 2 km from the river near Myrtle Grove, Louisiana, at a CRMS (Coastwide Reference Monitoring System) site. The CRMS site consists of a surface elevation table (SET) and marker horizon established in 2008. The surface elevation relative to a rod driven to refusal (26 m) and the sedimentation above the marker horizon is measured semiannually. Adjacent to this site we have added three borehole optical fiber strainmeters that have been providing continuous records of displacement between the near-surface and depths of 10, 26, and 42 m. The instruments provide unprecedented resolution for compaction studies (see Hatfield et al. abstract). We regularly record teleseismic events with amplitudes <1 μm. The records also show a number of days-long compaction and rebound events of less than 1 mm, resulting from changes in the weather and water level. We have attached GPS to each of the wells. For the deepest well, the GPS is anchored to the bottom of the well with the base of the optical strainmeter. For the other two wells, the GPS is anchored to the upper casing of the well. While drilling the wells, a 5" diameter continuous core was collected reaching the Pleistocene boundary at 37 m depth (see Bridgeman et al. abstract). The silty uppermost 10 m, comprised of proximal overbank deposits, reveal up to 5-6 m of subsidence over the past 3000 years. In contrast, the surficial sediments ( 70 cm) are almost entirely organic matter and show little subsidence. The SET shows only 0.4 mm/yr for a 7.4 yr time window. Over the first year, the strainmeters show no long-term compaction or extension greater than ± 0.5 mm. Precise processing of the available GPS data indicates the

  12. Emotional Abilities in Children with Oppositional Defiant Disorder (ODD): Impairments in Perspective-Taking and Understanding Mixed Emotions are Associated with High Callous-Unemotional Traits.

    Science.gov (United States)

    O'Kearney, Richard; Salmon, Karen; Liwag, Maria; Fortune, Clare-Ann; Dawel, Amy

    2017-04-01

    Most studies of emotion abilities in disruptive children focus on emotion expression recognition. This study compared 74 children aged 4-8 years with ODD to 45 comparison children (33 healthy; 12 with an anxiety disorder) on behaviourally assessed measures of emotion perception, emotion perspective-taking, knowledge of emotions causes and understanding ambivalent emotions and on parent-reported cognitive and affective empathy. Adjusting for child's sex, age and expressive language ODD children showed a paucity in attributing causes to emotions but no other deficits relative to the comparison groups. ODD boys with high levels of callous-unemotional traits (CU) (n = 22) showed deficits relative to low CU ODD boys (n = 25) in emotion perspective-taking and in understanding ambivalent emotions. Low CU ODD boys did not differ from the healthy typically developing boys (n = 12). Impairments in emotion perceptive-taking and understanding mixed emotions in ODD boys are associated with the presence of a high level of CU.

  13. Understanding and Improving Health Education Among First-time Parents of Infants With Sickle Cell Anemia in Alabama: A Mixed Methods Approach

    Science.gov (United States)

    Lebensburger, Jeffrey D.; Grosse, Scott D.; Altice, Jessica L.; Thierry, JoAnn M.; Ivankova, Nataliya V.

    2015-01-01

    Summary With the increase in access to medical information, parents can acquire health information from multiple sources. An understanding of parents' reactions to a newborn infant's diagnosis of sickle cell anemia and how they acquire knowledge can identify parent beliefs and preferences about the process of sickle cell education. This study utilized a sequential exploratory mixed methods design. First, qualitative interviews were conducted with 8 parents of infants with sickle cell anemia to understand the process of health education. Second, quantitative surveys were conducted with 22 other parents to test qualitative findings. Parents of infants with sickle cell anemia expressed a high level of fear at the time of notification of a positive screen. Parents desired an understanding of how to identify acute complications of disease and how sickle cell will alter their child's life. Parents actively sought information at the time they were told their child had sickle cell disease. Sickle cell education should begin at time of notification of positive newborn screening results and address identified parent concerns. Health care providers should build trust with parents and provide them with immediate access to educational materials. Hematologists should work with primary care providers to develop complementary educational programs and resources. PMID:25072367

  14. An Exploratory Sequential Mixed Methods Approach to Understanding Researchers’ Data Management Practices at UVM: Integrated Findings to Develop Research Data Services

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Berman

    2017-03-01

    Full Text Available This is the third in a series of articles reporting on a study of researcher data management practices and data services at the University of Vermont. This article reports on the integrated findings of an exploratory sequential mixed methods research design aimed to understand data management behaviors and challenges of faculty at the University of Vermont (UVM in order to develop relevant research data services. The exploratory sequential mixed methods design is characterized by an initial qualitative phase of data collection and analysis, followed by a phase of quantitative data collection and analysis, with a final phase of integration or linking of data from the two separate strands of data. A joint display was used to integrate data focused on the three primary research questions: How do faculty at UVM manage their research data, in particular how do they share and preserve data in the long-term?; What challenges or barriers do UVM faculty face in effectively managing their research data?; and What institutional data management support or services are UVM faculty interested in? As a result of the analysis, this study suggests four major areas of research data services for UVM to address: infrastructure, metadata, data analysis and statistical support, and informational research data services. The implementation of these potential areas of research data services is underscored by the need for cross-campus collaboration and support.

  15. Understanding neutrino masses and mixings

    Indian Academy of Sciences (India)

    that all the above data can be understood in terms of oscillations of the three known neutrinos, i.e., among themselves. since the ... are expressed in terms of the mass eigenstates. ( = 1 2 3) as follows: « = И ... down by one order of magnitude. 1.1.4 Н 3. The reactor experiments CHOOZ and PALO VERDE imply that Н 3 ≤.

  16. Understanding the causes and consequences of injuries to adolescents growing up in poverty in Ethiopia, Andhra Pradesh (India), Vietnam and Peru: a mixed method study.

    Science.gov (United States)

    Morrow, Virginia; Barnett, Inka; Vujcich, Daniel

    2014-01-01

    The World Health Organization estimates that almost half of all premature deaths among 15- to 19-year olds can be attributed to injuries with most (95%) fatal injuries occurring in low- and middle-income countries. Yet the evidence base for adolescent injuries in low-income countries is poor. This article uses a mixed method approach to gain an understanding of patterns, causes and consequences of unintentional injuries among adolescents aged between 14 and 16 years in four low-income country settings. Survey data collected in 2009 in Ethiopia, India (Andhra Pradesh), Peru and Vietnam (from ~900 adolescents in each country) were integrated with qualitative research (conducted between 2007 and 2011) with a nested sample of older cohort children in Ethiopia (n = 25) and India (n = 25) using an iterative process. Logistic regression models were fitted to examine potential risk factors for injuries. Injuries were a concern for adolescents in all countries and occurred during work, recreation and sports or transportation. Being male was associated with an increased risk for all types of injuries, whereas being poor was only significantly associated with work injuries. Area of residence (urban vs rural) made a difference in some countries and for some kinds of injuries as did perceived health status. Qualitative findings highlight the consequences of injuries not only for the adolescents but also for the social and economic status of the entire household. Injury prevention programmes need to be specific to cultural and environmental settings, expectations of adolescent's responsibilities and responsive to the context of poverty.

  17. EBT Payment for Online Grocery Orders: a Mixed-Methods Study to Understand Its Uptake among SNAP Recipients and the Barriers to and Motivators for Its Use.

    Science.gov (United States)

    Martinez, Olivia; Tagliaferro, Barbara; Rodriguez, Noemi; Athens, Jessica; Abrams, Courtney; Elbel, Brian

    2018-04-01

    To examine Supplemental Nutrition Assistance Program (SNAP) recipients' use of the first online supermarket accepting Electronic Benefit Transfer (EBT) payment. In this mixed-methods study, the authors collected EBT purchase data from an online grocer and attempted a randomized controlled trial in the South Bronx, New York City, followed by focus groups with SNAP beneficiaries aged ≥18 years. Participants were randomized to shop at their usual grocery store or an online supermarket for 3 months. Focus groups explored barriers and motivators to online EBT redemption. Few participants made online purchases, even when incentivized in the randomized controlled trial. Qualitative findings highlighted a lack of perceived control over the online food selection process as a key barrier to purchasing food online. Motivators included fast, free shipping and discounts. Electronic Benefit Transfer for online grocery purchases has the potential to increase food access among SNAP beneficiaries, but challenges exist to this new food buying option. Understanding online food shopping barriers and motivators is critical to the success of policies targeting the online expansion of SNAP benefits. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  18. Primary Radiation Damage in Materials. Review of Current Understanding and Proposed New Standard Displacement Damage Model to Incorporate in Cascade Defect Production Efficiency and Mixing Effects

    International Nuclear Information System (INIS)

    Nordlund, Kai; Sand, Andrea E.; Granberg, Fredric; Zinkle, Steven J.; Stoller, Roger; Averback, Robert S.; Suzudo, Tomoaki; Malerba, Lorenzo; Banhart, Florian; Weber, William J.; Willaime, Francois; Dudarev, Sergei; Simeone, David

    2015-01-01

    Under the auspices of the NEA Nuclear Science Committee (NSC), the Working Party on Multi-scale Modelling of Fuels and Structural Materials for Nuclear Systems (WPMM) was established in 2008 to assess the scientific and engineering aspects of fuels and structural materials, aiming at evaluating multi-scale models and simulations as validated predictive tools for the design of nuclear systems, fuel fabrication and performance. The WPMM's objective is to promote the exchange of information on models and simulations of nuclear materials, theoretical and computational methods, experimental validation, and related topics. It also provides member countries with up-to-date information, shared data, models and expertise. The WPMM Expert Group on Primary Radiation Damage (PRD) was established in 2009 to determine the limitations of the NRT-dpa standard, in the light of both atomistic simulations and known experimental discrepancies, to revisit the NRT-dpa standard and to examine the possibility of proposing a new improved standard of primary damage characteristics. This report reviews the current understanding of primary radiation damage from neutrons, ions and electrons (excluding photons, atomic clusters and more exotic particles), with emphasis on the range of validity of the 'displacement per atom' (dpa) concept in all major classes of materials with the exception of organics. The report also introduces an 'athermal recombination-corrected dpa' (arc-dpa) relation that uses a relatively simple functional to address the well-known issue that 'displacement per atom' (dpa) overestimates damage production in metals under energetic displacement cascade conditions, as well as a 'replacements-per-atom' (rpa) equation, also using a relatively simple functional, that accounts for the fact that dpa is understood to severely underestimate actual atom relocation (ion beam mixing) in metals. (authors)

  19. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    Science.gov (United States)

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-03

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length.

  20. Building a progressive vertical integration

    International Nuclear Information System (INIS)

    Charette, D.

    2008-01-01

    AAER Inc. is a Quebec-based company that manufactures turbines using proven European designs. This presentation discussed the company's business model. The company places an emphasis on identifying strategic and key components currently available for its turbines. Market analyses are performed in order to determine ideal suppliers and define business strategies and needs. The company invests in long-term relationships with its suppliers. Business partners for AAER are of a similar size and have a mutual understanding and respect for the company's business practices. Long-term agreements with suppliers are signed in order to ensure reliability and control over costs. Progressive vertical integration has been achieved by progressively manufacturing key components and integrating a North American supply chain. The company's secure supply chain and progressive vertical integration has significantly reduced financial costs and provided better quality control. It was concluded that vertical integration has also allowed AAER to provide better customer service and reduce transportation costs. tabs., figs

  1. Global Vertical Reference Frame

    Czech Academy of Sciences Publication Activity Database

    Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.

    2004-01-01

    Roč. 33, - (2004), s. 404-407 ISSN 1436-3445 Institutional research plan: CEZ:AV0Z1003909 Keywords : geopotential WO * vertical systems * global vertical frame Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  2. Vertical axis wind turbines

    Science.gov (United States)

    Krivcov, Vladimir [Miass, RU; Krivospitski, Vladimir [Miass, RU; Maksimov, Vasili [Miass, RU; Halstead, Richard [Rohnert Park, CA; Grahov, Jurij [Miass, RU

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  3. Mixing Over Rough Topography

    Science.gov (United States)

    2017-10-25

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Mixing Over Rough Topography Michael C. Gregg APL/UW...OBJECTIVES To understand mixing over rough topography. APPROACH To supplement NRL’s Mixing Over Rough Topography (MORT) measurements over ...to 1) Assess hydraulic control along lines crossing the bank, and 2) Measure turbulent dissipation rates over the bank. WORK COMPLETED The

  4. Measurement of the partial branching fraction for inclusive semileptonic B meson decays to light hadrons B → Xulv and an improved determination of the quark-mixing matrix element vertical stroke Vub

    International Nuclear Information System (INIS)

    Volk, Alexei

    2009-01-01

    This thesis presents an analysis of inclusive semileptonic B→ X u e anti ν e decays using approximately 454 million Υ(4S)→B anti B decays collected during the years 1999 to 2008 with the BABAR detector. The electron energy, E e , and the invariant mass squared of the electron-neutrino pair, q 2 , are reconstructed, where the neutrino kinematics is deduced from the decay products of both B mesons. The final hadronic state, X u , consists of a sum of many hadronic channels, each of which contains at least one u quark. The variables q 2 and E e are then combined to compute the maximum kinematically allowed invariant mass squared of the hadronic system, s h max . Using these kinematic quantities, the partial branching fraction, ΔB(B → X u lv), unfolded for detector effects, is measured to be ΔB(E e >2.0 GeV, s h max 2 ) (3.33±0.18±0.21) x 10 -4 in the Υ(4S) and ΔB(E e >1.9 GeV, s h max 2 )= (4.57±0.24±0.32) x 10 -4 in the B meson rest frames. The quoted errors are statistical and systematic, respectively. The CKM matrix element vertical stroke V ub vertical stroke is determined from the measured ΔB using theoretical calculation based on Heavy Quark Expansion. The result is vertical stroke V ub vertical stroke =(4.19±0.18 -0.20-0.25 +0.26+0.26 ) x 10 -3 , where the errors represent experimental uncertainties, uncertainties from HQE parameters and theoretical uncertainties, respectively. (orig.)

  5. Transcending the Quantitative-Qualitative Divide with Mixed Methods Research: A Multidimensional Framework for Understanding Congruence and Completeness in the Study of Values

    Science.gov (United States)

    McLafferty, Charles L., Jr.; Slate, John R.; Onwuegbuzie, Anthony J.

    2010-01-01

    Quantitative research dominates published literature in the helping professions. Mixed methods research, which integrates quantitative and qualitative methodologies, has received a lukewarm reception. The authors address the iterative separation that infuses theory, praxis, philosophy, methodology, training, and public perception and propose a…

  6. Offset vertical radar profiling

    Science.gov (United States)

    Witten, A.; Lane, J.

    2003-01-01

    Diffraction tomography imaging was applied to VRP data acquired by vertically moving a receiving antenna in a number of wells. This procedure simulated a vertical downhole receiver array. Similarly, a transmitting antenna was sequentially moved along a series of radial lines extending outward from the receiver wells. This provided a sequence of multistatic data sets and, from each data set, a two-dimensional vertical cross-sectional image of spatial variations in wave speed was reconstructed.

  7. Mixed marriages

    Directory of Open Access Journals (Sweden)

    Crnić-Pejović Marija

    2005-01-01

    Full Text Available Until the II World War, the population of the Boka Kotorska Bay was a mixture of Orthodox and Catholic confessions: approximately two thirds of the population was Orthodox, while one third belonged to the Catholics. In spite of the religious affiliation, mixed marriages were relatively often between these two groups. Based on a research in archives, this paper deals with such mixed marriages, formed mostly in 18th and 19th century, in the area of Herceg Novi. The second half of 19th century witnessed 639 of marriages, or 12,78 marriages per year, out of which 72 were mixed or 8,87%. In this particular period, 64 Catholic males married Orthodox females, while only 8 Orthodox males married Catholic females. The Church influence on the society was significant, including issues related to marriage, which sometimes created troubles for mixed marriages; however, positive civil and church regulations supported mixed marriages. Marriages between people of a different religious confession thus created wider kinship affiliations, which in turn enhanced religious tolerance, intertwining of different cultures and customs, and acceptance of different political and social views. The tolerance therefore affected political and social turmoil especially in troubled times, which made many issues easier: troubled issues were solved more rationally, and there were not so many persecutions based on someone’s religious affiliation. We need a wider perspective and a broader research on the Boka Kotorska Bay in order to understand how marriages and kinship ties affected a way of life and intertwining of cultural models of the East and West.

  8. Measurement of the partial branching fraction for inclusive semileptonic B meson decays to light hadrons B {yields} X{sub u}lv and an improved determination of the quark-mixing matrix element vertical stroke V{sub ub} vertical stroke

    Energy Technology Data Exchange (ETDEWEB)

    Volk, Alexei

    2009-07-01

    This thesis presents an analysis of inclusive semileptonic B{yields} X{sub u}e anti {nu}{sub e} decays using approximately 454 million {upsilon}(4S){yields}B anti B decays collected during the years 1999 to 2008 with the BABAR detector. The electron energy, E{sub e}, and the invariant mass squared of the electron-neutrino pair, q{sup 2}, are reconstructed, where the neutrino kinematics is deduced from the decay products of both B mesons. The final hadronic state, X{sub u}, consists of a sum of many hadronic channels, each of which contains at least one u quark. The variables q{sup 2} and E{sub e} are then combined to compute the maximum kinematically allowed invariant mass squared of the hadronic system, s{sub h}{sup max}. Using these kinematic quantities, the partial branching fraction, {delta}B(B {yields} X{sub u}lv), unfolded for detector effects, is measured to be {delta}B(E{sub e}>2.0 GeV, s{sub h}{sup max}<3.52 GeV{sup 2}) (3.33{+-}0.18{+-}0.21) x 10{sup -4} in the {upsilon}(4S) and {delta}B(E{sub e}>1.9 GeV, s{sub h}{sup max}<3.5 GeV{sup 2})= (4.57{+-}0.24{+-}0.32) x 10{sup -4} in the B meson rest frames. The quoted errors are statistical and systematic, respectively. The CKM matrix element vertical stroke V{sub ub} vertical stroke is determined from the measured {delta}B using theoretical calculation based on Heavy Quark Expansion. The result is vertical stroke V{sub ub} vertical stroke =(4.19{+-}0.18{sub -0.20-0.25}{sup +0.26+0.26}) x 10{sup -3}, where the errors represent experimental uncertainties, uncertainties from HQE parameters and theoretical uncertainties, respectively. (orig.)

  9. Mixed segmentation

    DEFF Research Database (Denmark)

    Hansen, Allan Grutt; Bonde, Anders; Aagaard, Morten

    This book is about using recent developments in the fields of data analytics and data visualization to frame new ways of identifying target groups in media communication. Based on a mixed-methods approach, the authors combine psychophysiological monitoring (galvanic skin response) with textual...... content analysis and audience segmentation in a single-source perspective. The aim is to explain and understand target groups in relation to, on the one hand, emotional response to commercials or other forms of audio-visual communication and, on the other hand, living preferences and personality traits...

  10. Vertical pump assembly

    International Nuclear Information System (INIS)

    Dohnal, M.; Rosel, J.; Skarka, V.

    1988-01-01

    The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig

  11. Analytical Aerodynamic Simulation Tools for Vertical Axis Wind Turbines

    International Nuclear Information System (INIS)

    Deglaire, Paul

    2010-01-01

    Wind power is a renewable energy source that is today the fastest growing solution to reduce CO 2 emissions in the electric energy mix. Upwind horizontal axis wind turbine with three blades has been the preferred technical choice for more than two decades. This horizontal axis concept is today widely leading the market. The current PhD thesis will cover an alternative type of wind turbine with straight blades and rotating along the vertical axis. A brief overview of the main differences between the horizontal and vertical axis concept has been made. However the main focus of this thesis is the aerodynamics of the wind turbine blades. Making aerodynamically efficient turbines starts with efficient blades. Making efficient blades requires a good understanding of the physical phenomena and effective simulations tools to model them. The specific aerodynamics for straight bladed vertical axis turbine flow are reviewed together with the standard aerodynamic simulations tools that have been used in the past by blade and rotor designer. A reasonably fast (regarding computer power) and accurate (regarding comparison with experimental results) simulation method was still lacking in the field prior to the current work. This thesis aims at designing such a method. Analytical methods can be used to model complex flow if the geometry is simple. Therefore, a conformal mapping method is derived to transform any set of section into a set of standard circles. Then analytical procedures are generalized to simulate moving multibody sections in the complex vertical flows and forces experienced by the blades. Finally the fast semi analytical aerodynamic algorithm boosted by fast multipole methods to handle high number of vortices is coupled with a simple structural model of the rotor to investigate potential aeroelastic instabilities. Together with these advanced simulation tools, a standard double multiple streamtube model has been developed and used to design several straight bladed

  12. Optimizing the strategic patient mix

    NARCIS (Netherlands)

    Vanberkel, P.T.; Boucherie, Richardus J.; Hans, Elias W.; Hurink, Johann L.

    In this paper we address the decision of choosing a patient mix for a hospital that leads to the most beneficial treatment case mix. We illustrate how capacity, case mix and patient mix decisions are interrelated and how understanding this complex relationship is crucial for achieving the maximum

  13. Tropospheric Vertical Profiles of Aerosol Optical, Microphysical and Concentration Properties in the Frame of the Hygra-CD Campaign (Athens, Greece 2014: A Case Study of Long-Range Transport of Mixed Aerosols

    Directory of Open Access Journals (Sweden)

    Papayannis Alexandros

    2016-01-01

    Full Text Available Combined multi-wavelength aerosol Raman lidar and sun photometry measurements were performed during the HYGRA-CD campaign over Athens, Greece during May-June 2014. The retrieved aerosol optical properties (3 aerosol backscatter at 355-532-1064 nm and 2 aerosol extinction profiles at 355-532 nm were used as input to an inversion code to retrieve the aerosol microphysical properties (effective radius reff and number concentration N using regularization techniques. Additionally, the volume concentration profile was derived for fine particles using the LIRIC code. In this paper we selected a complex case study of long-range transport of mixed aerosols (biomass burning particles mixed with dust arriving over Athens between 10-12 June 2014 in the 1.5-4 km height. Between 2-3 km height we measured mean lidar ratios (LR ranging from 45 to 58 sr (at 355 and 532 nm, while the Ångström exponent (AE aerosol extinction-related values (355nm/532nm ranged between 0.8-1.3. The retrieved values of reff and N ranged from 0.19±0.07 to 0.22±0.07 μm and 460±230 to 2200±2800 cm-3, respectively. The aerosol linear depolarization ratio (δ at 532 nm was lower than 5-7% (except for the Saharan dust cases, where δ~10-15%.

  14. Advancing Understanding of the Surface Water Quality Regime of Contemporary Mixed-Land-Use Watersheds: An Application of the Experimental Watershed Method

    Directory of Open Access Journals (Sweden)

    Elliott Kellner

    2017-06-01

    Full Text Available A representative watershed was instrumented with five gauging sites (n = 5, partitioning the catchment into five nested-scale sub-watersheds. Four physiochemical variables were monitored: water temperature, pH, total dissolved solids (TDS, and dissolved oxygen (DO. Data were collected four days per week from October 2010–May 2014 at each gauging site. Statistical analyses indicated significant differences (p < 0.05 between nearly every monitoring site pairing for each physiochemical variable. The water temperature regime displayed a threshold/step-change condition, with an upshifted and more variable regime attributable to the impacts of urban land uses. TDS, pH, and DO displayed similar spatiotemporal trends, with increasing median concentrations from site #1 (agriculture to #3 (mixed-use urban and decreasing median concentrations from site #3 to #5 (suburban. Decreasing concentrations and increasing streamflow volume with stream distance, suggest the contribution of dilution processes to the physiochemical regime of the creek below urban site #3. DO concentrations exceeded water quality standards on an average of 31% of observation days. Results showed seasonal trends for each physiochemical parameter, with higher TDS, pH, and DO during the cold season (November–April relative to the warm season (May–October. Multivariate modeling results emphasize the importance of the pH/DO relationship in these systems, and demonstrate the potential utility of a simple two factor model (water temperature and pH in accurately predicting DO. Collectively, results highlight the interacting influences of natural (autotrophic photosynthesis, organic detritus loading and anthropogenic (road salt application factors on the physiochemical regime of mixed-land-use watersheds.

  15. Vertical sleeve gastrectomy

    Science.gov (United States)

    ... clots , infection Risks for vertical sleeve gastrectomy are: Gastritis (inflamed stomach lining), heartburn, or stomach ulcers Injury ... of the work. To lose weight and avoid complications from the procedure, you will need to follow ...

  16. Coordination in vertical jumping

    NARCIS (Netherlands)

    Bobbert, Maarten F.; van Ingen Schenau, Gerrit Jan

    1988-01-01

    The present study was designed to investigate for vertical jumping the relationships between muscle actions, movement pattern and jumping achievement. Ten skilled jumpers performed jumps with preparatory countermovement. Ground reaction forces and cinematographic data were recorded. In addition,

  17. Hybrid vertical cavity laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide.......A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide....

  18. 'New to me': changing patient understanding of psoriasis and identifying mechanisms of change. The Pso Well®patient materials mixed-methods feasibility study.

    Science.gov (United States)

    Nelson, P A; Kane, K; Pearce, C J; Bundy, C; Chisholm, A; Hilton, R; Thorneloe, R; Young, H; Griffiths, C E M; Cordingley, L

    2017-09-01

    Psoriasis is an inflammatory long-term condition involving comorbidities, unhealthy lifestyle and significant life impact. Patients' understanding of psoriasis is limited and support lacking. The Common-Sense Model of Self-Regulation of Health and Illness emphasizes the role of illness and treatment beliefs on coping and self-management. New 'Pso Well ® ' patient materials informed by the model, addressed psoriasis as a long-term condition, medication management and lifestyle behaviours. To investigate whether Pso Well ® materials (i) broaden understanding of psoriasis without increasing anxiety; (ii) are acceptable; and (iii) comprise features that appear to effect change. The Revised Illness Perceptions Questionnaire (IPQ-R modified) and the Hospital Anxiety and Depression Scale (HADS) were administered in patients before and after intervention. Numerical rating scales assessed perceptions of change in understanding and anxiety resulting from engagement with the materials. Qualitative interviews explored acceptability and perceived 'active ingredients'. Fifty-five patients completed pre- and postintervention questionnaires (56% female; median age 59 years). Postintervention, a large effect size was indicated in two IPQ-R domains - illness coherence [t(55) = -3·48, P = 0·001 (two-tailed), η 2  = 0·19] and personal control [t(55) = -2·98, P = 0·004 (two-tailed), η 2  = 0·14] - and a medium effect in one, treatment control [t(55) = -2·08, P = 0·042 (two-tailed), η 2  = 0·08]. HADS scores did not change. For numerical rating scales, 80% of participants reported increased understanding of psoriasis and none reported increased anxiety. Interviews with 19 patients indicated the materials were acceptable and usable. Factors reported to broaden understanding and promote engagement with self-management included linking of related disease aspects, personally relevant content and high-quality design. High-quality, theory-based psoriasis

  19. Understanding cancer survivors' information needs and information-seeking behaviors for complementary and alternative medicine from short- to long-term survival: a mixed-methods study.

    Science.gov (United States)

    Scarton, Lou Ann; Del Fiol, Guilherme; Oakley-Girvan, Ingrid; Gibson, Bryan; Logan, Robert; Workman, T Elizabeth

    2018-01-01

    The research examined complementary and alternative medicine (CAM) information-seeking behaviors and preferences from short- to long-term cancer survival, including goals, motivations, and information sources. A mixed-methods approach was used with cancer survivors from the "Assessment of Patients' Experience with Cancer Care" 2004 cohort. Data collection included a mail survey and phone interviews using the critical incident technique (CIT). Seventy survivors from the 2004 study responded to the survey, and eight participated in the CIT interviews. Quantitative results showed that CAM usage did not change significantly between 2004 and 2015. The following themes emerged from the CIT: families' and friends' provision of the initial introduction to a CAM, use of CAM to manage the emotional and psychological impact of cancer, utilization of trained CAM practitioners, and online resources as a prominent source for CAM information. The majority of participants expressed an interest in an online information-sharing portal for CAM. Patients continue to use CAM well into long-term cancer survivorship. Finding trustworthy sources for information on CAM presents many challenges such as reliability of source, conflicting information on efficacy, and unknown interactions with conventional medications. Study participants expressed interest in an online portal to meet these needs through patient testimonials and linkage of claims to the scientific literature. Such a portal could also aid medical librarians and clinicians in locating and evaluating CAM information on behalf of patients.

  20. Breakwaters with Vertical and Inclined Concrete Walls

    DEFF Research Database (Denmark)

    Burcharth, Hans Falk

    Following the PIANC PTC II working group on Analyses of Rubble Mound Breakwaters it was, in 1991, decided to form Working Group (WG) n° 28 on "Breakwaters with vertical and inclined concrete walls" The scope of the work was to achieve a better understanding of the overall safety aspects in the de......Following the PIANC PTC II working group on Analyses of Rubble Mound Breakwaters it was, in 1991, decided to form Working Group (WG) n° 28 on "Breakwaters with vertical and inclined concrete walls" The scope of the work was to achieve a better understanding of the overall safety aspects...

  1. Vertical and horizontal subsidiarity

    Directory of Open Access Journals (Sweden)

    Ivan V. Daniluk

    2016-02-01

    Full Text Available This article makes an attempt to analyze the principle of subsidiarity in its two main manifestations, namely vertical and horizontal, to outline the principles of relations between the state and regions within the vertical subsidiarity, and features a collaboration of the government and civil society within the horizontal subsidiarity. Scientists identify two types, or two levels of the subsidiarity principle: vertical subsidiarity and horizontal subsidiarity. First, vertical subsidiarity (or territorial concerning relations between the state and other levels of subnational government, such as regions and local authorities; second, horizontal subsidiarity (or functional concerns the relationship between state and citizen (and civil society. Vertical subsidiarity expressed in the context of the distribution of administrative responsibilities to the appropriate higher level lower levels relative to the state structure, ie giving more powers to local government. However, state intervention has subsidiary-lower action against local authorities in cases of insolvency last cope on their own, ie higher organisms intervene only if the duties are less authority is insufficient to achieve the goals. Horizontal subsidiarity is within the relationship between power and freedom, and is based on the assumption that the concern for the common good and the needs of common interest community, able to solve community members (as individuals and citizens’ associations and role of government, in accordance horizontal subsidiarity comes to attracting features subsidiarity assistance, programming, coordination and possibly control.

  2. Variation of vertical atmospheric stability by means of radon measurements and of sodar monitoring

    International Nuclear Information System (INIS)

    Guedalia, D.; Druilhet, A.; Fontan, J.; N'tsila, A.

    1980-01-01

    Continuous measurements of radon at ground level are used to infer variations in equivalent mixing height and atmospheric vertical stability. Simultaneous determinations of the height of the inversion layer, when present, permit, with the use of sodar techniques, the estimation of radon flux from the ground and of the vertical diffusion coefficient. The two sets of data often indicate similar variations in mixing height

  3. Using spatial-stream-network models and long-term data to understand and predict dynamics of faecal contamination in a mixed land-use catchment.

    Science.gov (United States)

    Neill, Aaron James; Tetzlaff, Doerthe; Strachan, Norval James Colin; Hough, Rupert Lloyd; Avery, Lisa Marie; Watson, Helen; Soulsby, Chris

    2018-01-15

    An 11year dataset of concentrations of E. coli at 10 spatially-distributed sites in a mixed land-use catchment in NE Scotland (52km 2 ) revealed that concentrations were not clearly associated with flow or season. The lack of a clear flow-concentration relationship may have been due to greater water fluxes from less-contaminated headwaters during high flows diluting downstream concentrations, the importance of persistent point sources of E. coli both anthropogenic and agricultural, and possibly the temporal resolution of the dataset. Point sources and year-round grazing of livestock probably obscured clear seasonality in concentrations. Multiple linear regression models identified potential for contamination by anthropogenic point sources as a significant predictor of long-term spatial patterns of low, average and high concentrations of E. coli. Neither arable nor pasture land was significant, even when accounting for hydrological connectivity with a topographic-index method. However, this may have reflected coarse-scale land-cover data inadequately representing "point sources" of agricultural contamination (e.g. direct defecation of livestock into the stream) and temporal changes in availability of E. coli from diffuse sources. Spatial-stream-network models (SSNMs) were applied in a novel context, and had value in making more robust catchment-scale predictions of concentrations of E. coli with estimates of uncertainty, and in enabling identification of potential "hot spots" of faecal contamination. Successfully managing faecal contamination of surface waters is vital for safeguarding public health. Our finding that concentrations of E. coli could not clearly be associated with flow or season may suggest that management strategies should not necessarily target only high flow events or summer when faecal contamination risk is often assumed to be greatest. Furthermore, we identified SSNMs as valuable tools for identifying possible "hot spots" of contamination which

  4. Understanding the link between leadership style, employee satisfaction, and absenteeism: a mixed methods design study in a mental health care institution

    Directory of Open Access Journals (Sweden)

    Elshout R

    2013-06-01

    Full Text Available Rachelle Elshout,1 Evelien Scherp,2 Christina M van der Feltz-Cornelis31Management of Cultural Diversity, Tilburg University, Tilburg, The Netherlands; 2Communication and Information Sciences, Tilburg University, Tilburg, The Netherlands; 3Tilburg School of Social and Behavioral Sciences, Tilburg University, Tilburg, The NetherlandsBackground: In service oriented industries, such as the health care sector, leadership styles have been suggested to influence employee satisfaction as well as outcomes in terms of service delivery. However, how this influence comes into effect has not been widely explored. Absenteeism may be a factor in this association; however, no studies are available on this subject in the mental health care setting, although this setting has been under a lot of strain lately to provide their services at lower costs. This may have an impact on employers, employees, and the delivery of services, and absenteeism due to illness of employees tends to already be rather high in this particular industry. This study explores the association between leadership style, absenteeism, and employee satisfaction in a stressful work environment, namely a post-merger specialty mental health care institution (MHCI in a country where MHCIs are under governmental pressure to lower their costs (The Netherlands.Methods: We used a mixed methods design with quantitative as well as qualitative research to explore the association between leadership style, sickness absence rates, and employee satisfaction levels in a specialty MHCI. In depth, semi-structured interviews were conducted with ten key informants and triangulated with documented research and a contrast between four departments provided by a factor analysis of the data from the employee satisfaction surveys and sickness rates. Data was analyzed thematically by means of coding and subsequent exploration of patterns. Data analysis was facilitated by qualitative analysis software

  5. Understanding the link between leadership style, employee satisfaction, and absenteeism: a mixed methods design study in a mental health care institution

    Science.gov (United States)

    Elshout, Rachelle; Scherp, Evelien; van der Feltz-Cornelis, Christina M

    2013-01-01

    Background In service oriented industries, such as the health care sector, leadership styles have been suggested to influence employee satisfaction as well as outcomes in terms of service delivery. However, how this influence comes into effect has not been widely explored. Absenteeism may be a factor in this association; however, no studies are available on this subject in the mental health care setting, although this setting has been under a lot of strain lately to provide their services at lower costs. This may have an impact on employers, employees, and the delivery of services, and absenteeism due to illness of employees tends to already be rather high in this particular industry. This study explores the association between leadership style, absenteeism, and employee satisfaction in a stressful work environment, namely a post-merger specialty mental health care institution (MHCI) in a country where MHCIs are under governmental pressure to lower their costs (The Netherlands). Methods We used a mixed methods design with quantitative as well as qualitative research to explore the association between leadership style, sickness absence rates, and employee satisfaction levels in a specialty MHCI. In depth, semi-structured interviews were conducted with ten key informants and triangulated with documented research and a contrast between four departments provided by a factor analysis of the data from the employee satisfaction surveys and sickness rates. Data was analyzed thematically by means of coding and subsequent exploration of patterns. Data analysis was facilitated by qualitative analysis software. Results Quantitative analysis revealed sickness rates of 5.7% in 2010, which is slightly higher than the 5.2% average national sickness rate in The Netherlands in 2010. A general pattern of association between low employee satisfaction, high sickness rates, and transactional leadership style in contrast to transformational leadership style was established. The

  6. Understanding the link between leadership style, employee satisfaction, and absenteeism: a mixed methods design study in a mental health care institution.

    Science.gov (United States)

    Elshout, Rachelle; Scherp, Evelien; van der Feltz-Cornelis, Christina M

    2013-01-01

    In service oriented industries, such as the health care sector, leadership styles have been suggested to influence employee satisfaction as well as outcomes in terms of service delivery. However, how this influence comes into effect has not been widely explored. Absenteeism may be a factor in this association; however, no studies are available on this subject in the mental health care setting, although this setting has been under a lot of strain lately to provide their services at lower costs. This may have an impact on employers, employees, and the delivery of services, and absenteeism due to illness of employees tends to already be rather high in this particular industry. This study explores the association between leadership style, absenteeism, and employee satisfaction in a stressful work environment, namely a post-merger specialty mental health care institution (MHCI) in a country where MHCIs are under governmental pressure to lower their costs (The Netherlands). We used a mixed methods design with quantitative as well as qualitative research to explore the association between leadership style, sickness absence rates, and employee satisfaction levels in a specialty MHCI. In depth, semi-structured interviews were conducted with ten key informants and triangulated with documented research and a contrast between four departments provided by a factor analysis of the data from the employee satisfaction surveys and sickness rates. Data was analyzed thematically by means of coding and subsequent exploration of patterns. Data analysis was facilitated by qualitative analysis software. Quantitative analysis revealed sickness rates of 5.7% in 2010, which is slightly higher than the 5.2% average national sickness rate in The Netherlands in 2010. A general pattern of association between low employee satisfaction, high sickness rates, and transactional leadership style in contrast to transformational leadership style was established. The association could be described best

  7. Vertical Profiles of Aerosol Optical and Microphysical Properties During a Rare Case of Long-range Transport of Mixed Biomass Burning-polluted Dust Aerosols from the Russian Federation-kazakhstan to Athens, Greece

    Directory of Open Access Journals (Sweden)

    Papayannis Alexandros

    2016-01-01

    Full Text Available Multi-wavelength aerosol Raman lidar measurements with elastic depolarization at 532 nm were combined with sun photometry during the HYGRA-CD campaign over Athens, Greece, on May-June 2014. We retrieved the aerosol optical [3 aerosol backscatter profiles (baer at 355-532-1064 nm, 2 aerosol extinction (aaer profiles at 355-532 nm and the aerosol linear depolarization ratio (δ at 532 nm] and microphysical properties [effective radius (reff, complex refractive index (m, single scattering albedo (ω]. We present a case study of a long distance transport (~3.500-4.000 km of biomass burning particles mixed with dust from the Russian Federation-Kazakhstan regions arriving over Athens on 21-23 May 2014 (1.7-3.5 km height. On 23 May, between 2-2.75 km we measured mean lidar ratios (LR of 35 sr (355 nm and 42 sr (532 nm, while the mean Ångström exponent (AE aerosol backscatter-related values (355nm/532nm and 532nm/1064nm were 2.05 and 1.22, respectively; the mean value of δ at 532 nm was measured to be 9%. For that day the retrieved mean aerosol microphysical properties at 2-2.75 km height were: reff=0.26 μm (fine mode, reff=2.15 μm (coarse mode, m=1.36+0.00024i, ω=0.999 (355 nm, fine mode, ω=0.992(355 nm, coarse mode, ω=0.997 (532 nm, fine mode, and ω=0.980 (532 nm, coarse mode.

  8. Mixed and Mixing Systems Worldwide

    African Journals Online (AJOL)

    Sean.Donlan

    MIXED AND MIXING SYSTEMS WORLDWIDE: A PREFACE. 2012 VOLUME 15 No 3 ... dissenters, Mixed Jurisdictions Worldwide galvanised scholarship on mixed systems, especially for jurists in those ... Comparative Law, the International Association of Legal Science and numerous law faculties across the classical ...

  9. On the vertical structure of wind gusts

    DEFF Research Database (Denmark)

    Suomi, I.; Gryning, Sven-Erik; Floors, Rogier Ralph

    2015-01-01

    The increasing size of wind turbines, their height and the area swept by their blades have revised the need for understanding the vertical structure of wind gusts. Information is needed for the whole profile. In this study, we analyzed turbulence measurements from a 100m high meteorological mast...

  10. Vertical market participation

    DEFF Research Database (Denmark)

    Schrader, Alexander; Martin, Stephen

    1998-01-01

    Firms that operate at both levels of vertically related Cournot oligopolies will purchase some input supplies from independent rivals, even though they can produce the good at a lower cost, driving up input price for nonintegrated firms at the final good level. Foreclosure, which avoids this stra...... this strategic behavior, yields better market performance than Cournot beliefs...

  11. Global Vertical Reference Frame

    Czech Academy of Sciences Publication Activity Database

    Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.

    -, č. 5 (2009), s. 53-63 ISSN 1801-8483 R&D Projects: GA ČR GA205/08/0328 Institutional research plan: CEZ:AV0Z10030501 Keywords : sea surface topography * satellite altimetry * vertical frames Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  12. Vertical organic transistors

    Science.gov (United States)

    Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

    2015-11-01

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted.

  13. Vertical activity estimation using 2D radar | Hakl | Scientia Militaria ...

    African Journals Online (AJOL)

    Understanding airspace activity is essential for airspace control. Being able to detect vertical activity in aircraft allows prediction of aircraft intent, thereby allowing more accurate situation awareness and correspondingly more appropriate airspace control response. The method for qualitative vertical activity estimation as ...

  14. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  15. Digital Microfluidic System with Vertical Functionality

    Directory of Open Access Journals (Sweden)

    Brian F. Bender

    2015-11-01

    Full Text Available Digital (droplet microfluidics (DµF is a powerful platform for automated lab-on-a-chip procedures, ranging from quantitative bioassays such as RT-qPCR to complete mammalian cell culturing. The simple MEMS processing protocols typically employed to fabricate DµF devices limit their functionality to two dimensions, and hence constrain the applications for which these devices can be used. This paper describes the integration of vertical functionality into a DµF platform by stacking two planar digital microfluidic devices, altering the electrode fabrication process, and incorporating channels for reversibly translating droplets between layers. Vertical droplet movement was modeled to advance the device design, and three applications that were previously unachievable using a conventional format are demonstrated: (1 solutions of calcium dichloride and sodium alginate were vertically mixed to produce a hydrogel with a radially symmetric gradient in crosslink density; (2 a calcium alginate hydrogel was formed within the through-well to create a particle sieve for filtering suspensions passed from one layer to the next; and (3 a cell spheroid formed using an on-chip hanging-drop was retrieved for use in downstream processing. The general capability of vertically delivering droplets between multiple stacked levels represents a processing innovation that increases DµF functionality and has many potential applications.

  16. Occlusal vertical dimension. Review article

    OpenAIRE

    Alvítez Temoche, Daniel Augusto; Facultad de Odontología de la Universidad Nacional Mayor de San Marcos.

    2016-01-01

    Modication of occlusal vertical dimension is a procedure that is often necessary for complex oral reha-bilitation treatments to get a functional occlusal for patients. is literature review was made on databases: Medline (PubMed), Scopus, Scielo, BSV (Bireme), ISI (Web of science) and Lilacs using the keywords “occlusal vertical dimension”,”altered vertical dimension”, “temporomandibular joint”, and “masticatory muscles”. It can be said that the management of occlusal vertical dimension is a s...

  17. Vertical mixing at intermediate depths in the Arctic boundary current

    OpenAIRE

    Lenn, Y. D.; Wiles, P. J.; Torres-Valdes, S.; Abrahamsen, E. P.; Rippeth, T. P.; Simpson, J. H.; Bacon, S.; Laxon, S. W.; Polyakov, I.; Ivanov, V.; Kirillov, S.

    2009-01-01

    Microstructure and hydrographic observations, during September 2007 in the boundary current on the East Siberian continental slope, document upper ocean stratification and along-stream water mass changes. A thin warm surface layer overrides a shallow halocline characterized by a similar to 40-m thick temperature minimum layer beginning at similar to 30 m depth. Below the halocline, well-defined thermohaline diffusive staircases extended downwards to warm Atlantic Water intrusions found at 200...

  18. Effects of Mixed Layer Shear on Vertical Heat Flux

    Science.gov (United States)

    2016-12-01

    0704–0188 Public reporting burden for this collection of information is estimated to average 1 hour per response , including the time for reviewing...you too all my classmates—Mike, Geoff, Colleen, Brian, Dave, Rich , and Sulleyman. It has been a pleasure. xiv THIS PAGE INTENTIONALLY LEFT BLANK...1 I. INTRODUCTION A. ARCTIC ENVIRONMENT The Arctic environment is of great interest to modern researchers in studying global climate change

  19. Vertical axis wind turbine

    International Nuclear Information System (INIS)

    Obretenov, V.; Tsalov, T.; Chakarov, T.

    2012-01-01

    In recent years, the interest in wind turbines with vertical axis noticeably increased. They have some important advantages: low cost, relatively simple structure, reliable packaging system of wind aggregate long period during which require no maintenance, low noise, independence of wind direction, etc.. The relatively low efficiency, however, makes them applicable mainly for small facilities. The work presents a methodology and software for approximately aerodynamic design of wind turbines of this type, and also analyzed the possibility of improving the efficiency of their workflow

  20. Vertical vector face lift.

    Science.gov (United States)

    Somoano, Brian; Chan, Joanna; Morganroth, Greg

    2011-01-01

    Facial rejuvenation using local anesthesia has evolved in the past decade as a safer option for patients seeking fewer complications and minimal downtime. Mini- and short-scar face lifts using more conservative incision lengths and extent of undermining can be effective in the younger patient with lower face laxity and minimal loose, elastotic neck skin. By incorporating both an anterior and posterior approach and using an incision length between the mini and more traditional face lift, the Vertical Vector Face Lift can achieve longer-lasting and natural results with lesser cost and risk. Submentoplasty and liposuction of the neck and jawline, fundamental components of the vertical vector face lift, act synergistically with superficial musculoaponeurotic system plication to reestablish a more youthful, sculpted cervicomental angle, even in patients with prominent jowls. Dramatic results can be achieved in the right patient by combining with other procedures such as injectable fillers, chin implants, laser resurfacing, or upper and lower blepharoplasties. © 2011 Wiley Periodicals, Inc.

  1. Carbon export by vertically migrating zooplankton

    DEFF Research Database (Denmark)

    Hansen, Agnethe Nøhr; Visser, André W.

    2016-01-01

    Through diel vertical migration (DVM), zooplankton add an active transport to the otherwise passive sinking of detrital material that constitutes the biological pump. This active transport has proven difficult to quantify. We present a model that estimates both the temporal and depth characterist...... is transported than at either equatorial or boreal latitudes. We estimate that the amount of carbon transported below the mixed layer by migrating zooplankton in the North Atlantic Ocean constitutes 27% (16–30%) of the total export flux associated with the biological pump in that region...

  2. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  3. Near-inertial waves and deep ocean mixing

    International Nuclear Information System (INIS)

    Shrira, V I; Townsend, W A

    2013-01-01

    For the existing pattern of global oceanic circulation to exist, there should be sufficiently strong turbulent mixing in the abyssal ocean, the mechanisms of which are not well understood as yet. The review discusses a plausible mechanism of deep ocean mixing caused by near-inertial waves in the abyssal ocean. It is well known how winds in the atmosphere generate near-inertial waves in the upper ocean, which then propagate downwards losing their energy in the process; only a fraction of the energy at the surface reaches the abyssal ocean. An open question is whether and, if yes, how these weakened inertial motions could cause mixing in the deep. We review the progress in the mathematical description of a mechanism that results in an intense breaking of near-inertial waves near the bottom of the ocean and thus enhances the mixing. We give an overview of the present state of understanding of the problem covering both the published and the unpublished results; we also outline the key open questions. For typical ocean stratification, the account of the horizontal component of the Earth's rotation leads to the existence of near-bottom wide waveguides for near-inertial waves. Due to the β-effect these waveguides are narrowing in the poleward direction. Near-inertial waves propagating poleward get trapped in the waveguides; we describe how in the process these waves are focusing more and more in the vertical direction, while simultaneously their group velocity tends to zero and wave-induced vertical shear significantly increases. This causes the development of shear instability, which is interpreted as wave breaking. Remarkably, this mechanism of local intensification of turbulent mixing in the abyssal ocean can be adequately described within the framework of linear theory. The qualitative picture is similar to wind wave breaking on a beach: the abyssal ocean always acts as a surf zone for near-inertial waves. (paper)

  4. Vertical Scope, Turbulence, and the Benefits of Commitment and Flexibility

    DEFF Research Database (Denmark)

    Claussen, Jörg; Kretschmer, Tobias; Stieglitz, Nils

    2015-01-01

    We address the contested state of theory and the mixed empirical evidence on the relationship between turbulence and vertical scope by studying how turbulence affects the benefits of commitment from integrated development of components and the benefits of flexibility from sourcing components...

  5. Physical characteristics of the coastal waters between Navapur and Umbharat, West coast of India. Part 2. Vertical homogeneity of temperature and salinity

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Sarma, R.V.

    and seasonal changes in these parameters, the vertical distribution was remarkably uniform on a seasonal basis at these stations having strong tidal currents during most part of the year, suggesting efficient mixing of the water layers. However, the vertical...

  6. Modelling the Diel Vertical Movement of Swordfish (Xiphias gladius Linnaeus, 1758 Based on Temperature and Depth Recorder Data

    Directory of Open Access Journals (Sweden)

    Bram Setyadji

    2016-03-01

    Full Text Available Understanding the vertical distribution of large pelagic fish, swordfish in particular, could improve our knowledge on its fisheries strategy, management and resource conservation. However the methods often require expensive tools and resources, which probably most scientists from the development countries couldn’t afford. Thus developing model on the diel vertical movement behavior of swordfish using number of hook between float (HBF and complete-set temperature and depth recorder (TDR data could be an alternative. In general context, capture depth distributions are a good indicator of the natural depth distribution of the fish if the entire depth range of the species is targeted by longline gear. The proposed sinusoidal model suggested that swordfish showed a diel pattern in depth distribution, marked by remained in the surface and mixed layer waters at night and dived into deeper waters during the day. Keywords: swordfish, behavior, HBF, TDR, sinusoidal model

  7. Semi-idealized modeling of lightning initiation related to vertical air motion and cloud microphysics

    Science.gov (United States)

    Wang, Fei; Zhang, Yijun; Zheng, Dong; Xu, Liangtao; Zhang, Wenjuan; Meng, Qing

    2017-10-01

    A three-dimensional charge-discharge numerical model is used, in a semi-idealized mode, to simulate a thunder-storm cell. Characteristics of the graupel microphysics and vertical air motion associated with the lightning initiation are revealed, which could be useful in retrieving charge strength during lightning when no charge-discharge model is available. The results show that the vertical air motion at the lightning initiation sites ( W ini) has a cubic polynomial correlation with the maximum updraft of the storm cell ( W cell-max), with the adjusted regression coefficient R 2 of approximately 0.97. Meanwhile, the graupel mixing ratio at the lightning initiation sites ( q g-ini) has a linear correlation with the maximum graupel mixing ratio of the storm cell ( q g-cell-max) and the initiation height ( z ini), with the coefficients being 0.86 and 0.85, respectively. These linear correlations are more significant during the middle and late stages of lightning activity. A zero-charge zone, namely, the area with very low net charge density between the main positive and negative charge layers, appears above the area of q g-cell-max and below the upper edge of the graupel region, and is found to be an important area for lightning initiation. Inside the zero-charge zone, large electric intensity forms, and the ratio of q ice (ice crystal mixing ratio) to q g (graupel mixing ratio) illustrates an exponential relationship to q g-ini. These relationships provide valuable clues to more accurately locating the high-risk area of lightning initiation in thunderstorms when only dual-polarization radar data or outputs from numerical models without charging/discharging schemes are available. The results can also help understand the environmental conditions at lightning initiation sites.

  8. Cubic interaction vertices for fermionic and bosonic arbitrary spin fields

    Science.gov (United States)

    Metsaev, R. R.

    2012-06-01

    Using the light-cone gauge approach to relativistic field dynamics, we study arbitrary spin fermionic and bosonic fields propagating in flat space of dimension greater than or equal to four. Generating functions of parity invariant cubic interaction vertices for totally symmetric and mixed-symmetry massive and massless fields are obtained. For the case of totally symmetric fields, we derive restrictions on the allowed values of spins and the number of derivatives. These restrictions provide a complete classification of parity invariant cubic interaction vertices for totally symmetric fermionic and bosonic fields. As an example of application of the light-cone formalism, we obtain simple expressions for the Yang-Mills and gravitational interactions of massive arbitrary spin fermionic fields. For some particular cases, using our light-cone cubic vertices, we discuss the corresponding manifestly Lorentz invariant and on-shell gauge invariant cubic vertices.

  9. Mixed parentage

    DEFF Research Database (Denmark)

    Bang Appel, Helene; Singla, Rashmi

    2016-01-01

    Despite an increase in cross border intimate relationships and children of mixed parentage, there is little mention or scholarship about them in the area of childhood and migrancy in the Nordic countries. The international literature implies historical pathologisation, contestation and current...... complex paradigms regarding these children. This chapter explores how children of mixed parentage negotiate their identities in the Danish context, where statistically and socially there are no widely acceptable terms for categorizing them. To this purpose, an empirical qualitative in...

  10. Vertical propagation of baroclinic Kelvin waves along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nethery, D.; Shankar, D.

    , this paper is intended to provide the motivation for studying the vertical propagation of coastal Kelvin waves with a general circulation model, allowing the influence of density variations, basin geometry, and mixing processes to be examined...

  11. The mixing of fluids

    International Nuclear Information System (INIS)

    Ottino, J.M.

    1989-01-01

    What do the eruption of Krakatau, the manufacture of puff pastry and the brightness of stars have in common? Each involves some aspect of mixing. Mixing also plays a critical role in modern technology. Chemical engineers rely on mixing to ensure that substances react properly, to produce polymer blends that exhibit unique properties and to disperse drag-reducing agents in pipelines. Yet in spite of its of its ubiquity in nature and industry, mixing is only imperfectly under-stood. Indeed, investigators cannot even settle on a common terminology: mixing is often referred to as stirring by oceanographers and geophysicists, as blending by polymer engineers and as agitation by process engineers. Regardless of what the process is called, there is little doubt that it is exceedingly complex and is found in a great variety of systems. In constructing a theory of fluid mixing, for example, one has to take into account fluids that can be miscible or partially miscible and reactive or inert, and flows that are slow and orderly or very fast and turbulent. It is therefore not surprising that no single theory can explain all aspect of mixing in fluids and that straightforward computations usually fail to capture all the important details. Still, both physical experiments and computer simulations can provide insight into the mixing process. Over the past several years the authors and his colleague have taken both approaches in an effort to increase understanding of various aspect of the process-particularly of mixing involving slow flows and viscous fluids such as oils

  12. How the "Understanding Research Evidence" Web-Based Video Series From the National Collaborating Centre for Methods and Tools Contributes to Public Health Capacity to Practice Evidence-Informed Decision Making: Mixed-Methods Evaluation.

    Science.gov (United States)

    Chan, Linda; Mackintosh, Jeannie; Dobbins, Maureen

    2017-09-28

    The National Collaborating Centre for Methods and Tools (NCCMT) offers workshops and webinars to build public health capacity for evidence-informed decision-making. Despite positive feedback for NCCMT workshops and resources, NCCMT users found key terms used in research papers difficult to understand. The Understanding Research Evidence (URE) videos use plain language, cartoon visuals, and public health examples to explain complex research concepts. The videos are posted on the NCCMT website and YouTube channel. The first four videos in the URE web-based video series, which explained odds ratios (ORs), confidence intervals (CIs), clinical significance, and forest plots, were evaluated. The evaluation examined how the videos affected public health professionals' practice. A mixed-methods approach was used to examine the delivery mode and the content of the videos. Specifically, the evaluation explored (1) whether the videos were effective at increasing knowledge on the four video topics, (2) whether public health professionals were satisfied with the videos, and (3) how public health professionals applied the knowledge gained from the videos in their work. A three-part evaluation was conducted to determine the effectiveness of the first four URE videos. The evaluation included a Web-based survey, telephone interviews, and pretest and posttests, which evaluated public health professionals' experience with the videos and how the videos affected their public health work. Participants were invited to participate in this evaluation through various open access, public health email lists, through informational flyers and posters at the Canadian Public Health Association (CPHA) conference, and through targeted recruitment to NCCMT's network. In the Web-based surveys (n=46), participants achieved higher scores on the knowledge assessment questions from watching the OR (P=.04), CI (P=.04), and clinical significance (P=.05) videos but not the forest plot (P=.12) video, as

  13. How the “Understanding Research Evidence” Web-Based Video Series From the National Collaborating Centre for Methods and Tools Contributes to Public Health Capacity to Practice Evidence-Informed Decision Making: Mixed-Methods Evaluation

    Science.gov (United States)

    Chan, Linda; Mackintosh, Jeannie

    2017-01-01

    Background The National Collaborating Centre for Methods and Tools (NCCMT) offers workshops and webinars to build public health capacity for evidence-informed decision-making. Despite positive feedback for NCCMT workshops and resources, NCCMT users found key terms used in research papers difficult to understand. The Understanding Research Evidence (URE) videos use plain language, cartoon visuals, and public health examples to explain complex research concepts. The videos are posted on the NCCMT website and YouTube channel. Objective The first four videos in the URE web-based video series, which explained odds ratios (ORs), confidence intervals (CIs), clinical significance, and forest plots, were evaluated. The evaluation examined how the videos affected public health professionals’ practice. A mixed-methods approach was used to examine the delivery mode and the content of the videos. Specifically, the evaluation explored (1) whether the videos were effective at increasing knowledge on the four video topics, (2) whether public health professionals were satisfied with the videos, and (3) how public health professionals applied the knowledge gained from the videos in their work. Methods A three-part evaluation was conducted to determine the effectiveness of the first four URE videos. The evaluation included a Web-based survey, telephone interviews, and pretest and posttests, which evaluated public health professionals’ experience with the videos and how the videos affected their public health work. Participants were invited to participate in this evaluation through various open access, public health email lists, through informational flyers and posters at the Canadian Public Health Association (CPHA) conference, and through targeted recruitment to NCCMT’s network. Results In the Web-based surveys (n=46), participants achieved higher scores on the knowledge assessment questions from watching the OR (P=.04), CI (P=.04), and clinical significance (P=.05) videos but

  14. Protected Vertices in Motzkin trees

    OpenAIRE

    Van Duzer, Anthony

    2017-01-01

    In this paper we find recurrence relations for the asymptotic probability a vertex is $k$ protected in all Motzkin trees. We use a similar technique to calculate the probabilities for balanced vertices of rank $k$. From this we calculate upper and lower bounds for the probability a vertex is balanced and upper and lower bounds for the expected rank of balanced vertices.

  15. The School Library Vertical File.

    Science.gov (United States)

    Smallwood, Carol

    1990-01-01

    Discusses the maintenance of vertical files in the school library. Topics covered include circulation, weeding, using materials for special displays, acquiring materials, policies on advertising and controversial issues, cross-references, subject headings, introducing students to vertical files, beginning a collection, and preservation. (MES)

  16. Analysis of vertical stability limits and vertical displacement event behavior on NSTX-U

    Science.gov (United States)

    Boyer, Mark; Battaglia, Devon; Gerhardt, Stefan; Menard, Jonathan; Mueller, Dennis; Myers, Clayton; Sabbagh, Steven; Smith, David

    2017-10-01

    The National Spherical Torus Experiment Upgrade (NSTX-U) completed its first run campaign in 2016, including commissioning a larger center-stack and three new tangentially aimed neutral beam sources. NSTX-U operates at increased aspect ratio due to the larger center-stack, making vertical stabilization more challenging. Since ST performance is improved at high elongation, improvements to the vertical control system were made, including use of multiple up-down-symmetric flux loop pairs for real-time estimation, and filtering to remove noise. Similar operating limits to those on NSTX (in terms of elongation and internal inductance) were achieved, now at higher aspect ratio. To better understand the observed limits and project to future operating points, a database of vertical displacement events and vertical oscillations observed during the plasma current ramp-up on NSTX/NSTX-U has been generated. Shots were clustered based on the characteristics of the VDEs/oscillations, and the plasma parameter regimes associated with the classes of behavior were studied. Results provide guidance for scenario development during ramp-up to avoid large oscillations at the time of diverting, and provide the means to assess stability of target scenarios for the next campaign. Results will also guide plans for improvements to the vertical control system. Work supported by U.S. D.O.E. Contract No. DE-AC02-09CH11466.

  17. Applying normalization process theory to understand implementation of a family violence screening and care model in maternal and child health nursing practice: a mixed method process evaluation of a randomised controlled trial.

    Science.gov (United States)

    Hooker, Leesa; Small, Rhonda; Humphreys, Cathy; Hegarty, Kelsey; Taft, Angela

    2015-03-28

    In Victoria, Australia, Maternal and Child Health (MCH) services deliver primary health care to families with children 0-6 years, focusing on health promotion, parenting support and early intervention. Family violence (FV) has been identified as a major public health concern, with increased prevalence in the child-bearing years. Victorian Government policy recommends routine FV screening of all women attending MCH services. Using Normalization Process Theory (NPT), we aimed to understand the barriers and facilitators of implementing an enhanced screening model into MCH nurse clinical practice. NPT informed the process evaluation of a pragmatic, cluster randomised controlled trial in eight MCH nurse teams in metropolitan Melbourne, Victoria, Australia. Using mixed methods (surveys and interviews), we explored the views of MCH nurses, MCH nurse team leaders, FV liaison workers and FV managers on implementation of the model. Quantitative data were analysed by comparing proportionate group differences and change within trial arm over time between interim and impact nurse surveys. Qualitative data were inductively coded, thematically analysed and mapped to NPT constructs (coherence, cognitive participation, collective action and reflexive monitoring) to enhance our understanding of the outcome evaluation. MCH nurse participation rates for interim and impact surveys were 79% (127/160) and 71% (114/160), respectively. Twenty-three key stakeholder interviews were completed. FV screening work was meaningful and valued by participants; however, the implementation coincided with a significant (government directed) change in clinical practice which impacted on full engagement with the model (coherence and cognitive participation). The use of MCH nurse-designed FV screening/management tools in focussed women's health consultations and links with FV services enhanced the participants' work (collective action). Monitoring of FV work (reflexive monitoring) was limited. The use of

  18. Trade Liberalisation and Vertical Integration

    DEFF Research Database (Denmark)

    Bache, Peter Arendorf; Laugesen, Anders

    We build a three-country model of international trade in final goods and intermediate inputs and study the relation between different types of trade liberalisation and vertical integration. Firms are heterogeneous with respect to both productivity and factor intensity as observed in data. Final......-good producers face decisions on exporting, vertical integration of intermediate-input production, and whether the intermediate-input production should be offshored to a low-wage country. We find that the fractions of final-good producers that pursue either vertical integration, offshoring, or exporting are all...... increasing when intermediate-input or final-goods trade is liberalised and when the fixed cost of vertical integration is reduced. At the same time, one observes firms that shift away from either vertical integration, offshoring, or exporting. Further, we provide guidance for testing the open...

  19. Vertical quantum dot with a vertically coupled charge detector

    International Nuclear Information System (INIS)

    Zaitsu, Koichiro; Kitamura, Yosuke; Ono, Keiji; Tarucha, Seigo

    2008-01-01

    We fabricated a vertical quantum dot equipped with a charge detector. The dot current flows vertically between the top and bottom contacts. The charge detector is formed at the bottom contact layer with a current channel constricted to the region just under the dot. This channel current is reduced by addition of an extra electron onto the dot due to the electrostatic coupling to the dot. The charge state of the vertical dot was detected, starting from zero electrons. The sensitivity of the charge detector was comparable to that previously reported for lateral dots with nearby quantum point contacts

  20. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear......Mixed Movements is a research project engaged in performance-based architectural drawing. Architectonic implementation questions relations between the human body and a body of architecture by the different ways we handle drawing materials. A drawing may explore architectonic problems at other...

  1. Can Earthworm "mix up" Soil Carbon Budgets in Temperate Forests Under Elevated Carbon Dioxide?

    Science.gov (United States)

    Sánchez-de León, Y.; González-Meler, M.; Sturchio, N. C.; Wise, D. H.; Norby, R. J.

    2008-12-01

    The effects of global change on earthworms and their associated feedbacks on soil and ecosystem processes have been largely overlooked. We studied how the responses of a temperate deciduous forest to elevated carbon dioxide atmospheric concentrations (e[CO2]) influence earthworms and the soil processes affected by them. Our objectives were to: i) identify soil layers of active soil mixing under e[CO2] and current carbon dioxide atmospheric concentrations (c[CO2]) using fallout cesium (137Cs), ii) study how e[CO2] affects earthworm populations, iii) understand the relationship between soil mixing and earthworms at our study site, and iv) identify the implications of earthworm-mediated soil mixing for the carbon budget of a temperate forest. To study soil mixing, we measured vertical 137Cs activity in soil cores (0-24 cm depth) collected in replicated e[CO2] and c[CO2] sweetgum (Liquidambar styraciflua) plots (n = 2) in a Free Air CO2 Enrichment (FACE) ecosystem experiment at Oak Ridge National Laboratory. We measured earthworm density and fresh weight in the plots in areas adjacent to where soil cores were taken. Preliminary results on the vertical distribution of 137Cs in the c[CO2] treatments showed that higher 137Cs activity was located from 8-16 cm depth and no 137Cs activity was measured below 20 cm. In contrast, in the e[CO2] treatment, peak 137Cs activity was slightly deeper (10-18 cm), and 137Cs activity was still measured below 22 cm. Mean earthworm density was higher in e[CO2] than c[CO2] treatments (168 m-2 and 87 m-2, respectively; p = 0.046); earthworm fresh weights, however, did not differ significantly between treatments (32 g m-2 and 18 g m-2, respectively; p = 0.182). The 137Cs vertical distribution suggest that soil mixing occurs deeper in e[CO2] than in c[CO2] treatments, which is consistent with higher earthworm densities in e[CO2] than in c[CO2] treatments. Mixing deeper low carbon content soil with shallower high carbon soil may result in a

  2. Salt balance and mixing in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    ), National Institute of Oceanography, Dona Paula, Goa for the purpose of evaluating the profiles of mixing, both vertical and horizontal. The surface salinity field is found to be controlled primarily by the circulation in the surface layer. The coastal...

  3. Mixing lengths scaling in a gravity flow

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory; Rivera, Micheal [Los Alamos National Laboratory; Chen, Jun [Los Alamos National Laboratory; Ecke, Robert E [Los Alamos National Laboratory

    2009-01-01

    We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model [1]: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadraticatly with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing length, approximately constant over the mixing zone of the stratified shear layer. We show in this paper how, in different flow configurations, this length can be related to the shear length of the flow {radical}({var_epsilon}/{partial_derivative}{sub z}u{sup 3}).

  4. The Vertical Dust Profile Over Gale Crater, Mars

    Science.gov (United States)

    Guzewich, Scott D.; Newman, C. E.; Smith, M. D.; Moores, J. E.; Smith, C. L.; Moore, C.; Richardson, M. I.; Kass, D.; Kleinböhl, A.; Mischna, M.; Martín-Torres, F. J.; Zorzano-Mier, M.-P.; Battalio, M.

    2017-12-01

    We create a vertically coarse, but complete, profile of dust mixing ratio from the surface to the upper atmosphere over Gale Crater, Mars, using the frequent joint atmospheric observations of the orbiting Mars Climate Sounder (MCS) and the Mars Science Laboratory Curiosity rover. Using these data and an estimate of planetary boundary layer (PBL) depth from the MarsWRF general circulation model, we divide the vertical column into three regions. The first region is the Gale Crater PBL, the second is the MCS-sampled region, and the third is between these first two. We solve for a well-mixed dust mixing ratio within this third (middle) layer of atmosphere to complete the profile. We identify a unique seasonal cycle of dust within each atmospheric layer. Within the Gale PBL, dust mixing ratio maximizes near southern hemisphere summer solstice (Ls = 270°) and minimizes near winter solstice (Ls = 90-100°) with a smooth sinusoidal transition between them. However, the layer above Gale Crater and below the MCS-sampled region more closely follows the global opacity cycle and has a maximum in opacity near Ls = 240° and exhibits a local minimum (associated with the "solsticial pause" in dust storm activity) near Ls = 270°. With knowledge of the complete vertical dust profile, we can also assess the frequency of high-altitude dust layers over Gale. We determine that 36% of MCS profiles near Gale Crater contain an "absolute" high-altitude dust layer wherein the dust mixing ratio is the maximum in the entire vertical column.

  5. The Vertical Structure of Urban Soils and Their Convergence Across Cities

    Science.gov (United States)

    The theoretical patterns for vertical soil structure (e.g., A-B-C ordering of horizons) are a basis for research methods and our understanding of ecosystem structure and function in general. A general understanding of how urban soils differ from non-urban soils vertically is need...

  6. The vertical geography of urban soils and its convergence across cities

    Science.gov (United States)

    The theoretical patterns for vertical soil structure (e.g., A-B-C ordering of horizons) are a basis for research methods and our understanding of ecosystem structure and function in general. A general understanding of how urban soils differ from non-urban soils vertically is need...

  7. Vertical axis wind turbine airfoil

    Science.gov (United States)

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  8. Trade Liberalisation and Vertical Integration

    DEFF Research Database (Denmark)

    Bache, Peter Arendorf; Laugesen, Anders Rosenstand

    We build a three-country model of international trade in final goods and intermediate inputs and study the relation between four different types of trade liberalisation and vertical integration. Firms are heterogeneous with respect to both productivity and factor (headquarter) intensity. Final......-good producers face decisions on exporting, vertical integration of intermediate-input production, and whether the intermediate-input production should be offshored to a low-wage country. We find that the fractions of final-good producers that pursue either vertical integration, offshoring, or exporting are all...... increasing when intermediate-input trade or final-goods trade is liberalised. Finally, we provide guidance for testing the open-economy property rights theory of the firm using firm-level data and surprisingly show that the relationship between factor (headquarter) intensity and the likelihood of vertical...

  9. Diagnosis of hydrometeor profiles from area-mean vertical-velocity data

    Science.gov (United States)

    Braun, Scott A.; Houze, Robert A., Jr.

    1995-01-01

    A simple one-dimensional microphysical retrieval model is developed for estimating vertical profiles of liquid and frozen hydrometeor mixing ratios from observed vertical profiles of area-mean vertical velocity in regions of convective and/or stratiform precipitation. The mean vertical-velocity profiles can be obtained from Doppler radar (single and dual) or other means. The one-dimensional results are shown to be in good agreement with two-dimensional microphysical fields from a previous study. Sensitivity tests are performed.

  10. Reduction of vertical transport in two-dimensional stably stratified forced shear flows

    Science.gov (United States)

    Toqué, Nathalie; Lignières, François; Vincent, Alain

    2006-04-01

    The effect of stable stratification on the vertical transport of passive contaminants in forced, stationary, two-dimensional (2D) and inhomogeneous shear turbulence is investigated numerically. The mean flow consists of several superimposed parallel sheared layers in a stably stratified medium. We find that, as stratification increases, the vertical transport decreases much faster than predicted by mixing length estimates. For the highest stratification, particles vertical dispersion nearly vanishes. The proposed interpretation emphasizes the role of weakly sheared layers where the relative increase of the mean horizontal velocity with respect to the root-mean-square (rms) vertical velocity causes the decrease of the Lagrangian correlation timescale.

  11. The TEXT upgrade vertical interferometer

    International Nuclear Information System (INIS)

    Hallock, G.A.; Gartman, M.L.; Li, W.; Chiang, K.; Shin, S.; Castles, R.L.; Chatterjee, R.; Rahman, A.S.

    1992-01-01

    A far-infrared interferometer has been installed on TEXT upgrade to obtain electron density profiles. The primary system views the plasma vertically through a set of large (60-cm radialx7.62-cm toroidal) diagnostic ports. A 1-cm channel spacing (59 channels total) and fast electronic time response is used, to provide high resolution for radial profiles and perturbation experiments. Initial operation of the vertical system was obtained late in 1991, with six operating channels

  12. Cellular heterogeneity in vertical growth phase melanoma.

    Science.gov (United States)

    Laga, Alvaro C; Murphy, George F

    2010-12-01

    Melanoma growing as a tumorigenic nodule is one of the most virulent neoplasms to which the flesh is heir. At a considerably small tumor size, it incurs significant risk for widespread metastatic dissemination. There are no effective means of surgical intervention, chemical therapy, or immunologic therapy for advanced and metastatic melanoma. To review the literature and highlight recent cardinal advances in the understanding of melanoma vertical growth, with specific emphasis on how its recognition and characterization may be applied to diagnostic practice and development of novel investigative approaches. Literature review, archival material, personal experience, and research collaborators. The study of tumorigenic melanoma, both in primary lesions and in metastases, is the key to the eventual eradication of this highly virulent neoplasm that may disseminate widely when only occupying the volume of a grain of rice. Morphology often provides the first insight into structure and function. A growing database using meticulous and inclusive criteria to define tumor stem cells in the context of clinically relevant models now indicates that the key to melanoma heterogeneity may reside in a small subpopulation with the ability to self-renew and form tumors despite most cells present being significantly less virulent. Hopefully, from these insights into melanoma tumor progression from radial growth phase to heterogeneous and tumorigenic vertical growth phase will come additional answers to how smart therapies may be developed that specifically target those vertical growth phase cells that most pertain to patient survival.

  13. Assessing the impacts of seasonal and vertical atmospheric conditions on air quality over the Pearl River Delta region

    Science.gov (United States)

    Tong, Cheuk Hei Marcus; Yim, Steve Hung Lam; Rothenberg, Daniel; Wang, Chien; Lin, Chuan-Yao; Chen, Yongqin David; Lau, Ngar Cheung

    2018-05-01

    Air pollution is an increasingly concerning problem in many metropolitan areas due to its adverse public health and environmental impacts. Vertical atmospheric conditions have strong effects on vertical mixing of air pollutants, which directly affects surface air quality. The characteristics and magnitude of how vertical atmospheric conditions affect surface air quality, which are critical to future air quality projections, have not yet been fully understood. This study aims to enhance understanding of the annual and seasonal sensitivities of air pollution to both surface and vertical atmospheric conditions. Based on both surface and vertical meteorological characteristics provided by 1994-2003 monthly dynamic downscaling data from the Weather and Research Forecast Model, we develop generalized linear models (GLMs) to study the relationships between surface air pollutants (ozone, respirable suspended particulates, and sulfur dioxide) and atmospheric conditions in the Pearl River Delta (PRD) region. Applying Principal Component Regression (PCR) to address multi-collinearity, we study the contributions of various meteorological variables to pollutants' concentration levels based on the loading and model coefficient of major principal components. Our results show that relatively high pollutant concentration occurs under relatively low mid-level troposphere temperature gradients, low relative humidity, weak southerly wind (or strong northerly wind) and weak westerly wind (or strong easterly wind). Moreover, the correlations vary among pollutant species, seasons, and meteorological variables at various altitudes. In general, pollutant sensitivity to meteorological variables is found to be greater in winter than in other seasons, and the sensitivity of ozone to meteorology differs from that of the other two pollutants. Applying our GLMs to anomalous air pollution episodes, we find that meteorological variables up to mid troposphere (∼700 mb) play an important role in

  14. Frontogenesis and turbulent mixing

    Science.gov (United States)

    Zhang, S.; Chen, F.; Shang, Q.

    2017-12-01

    A hydrological investigation was conducted in the shelf of eastern Hainan island during July 2012. With the in-situ measurements from four cross-shelf sections and satellite data, the submesoscale process of the fronts are discussed in this paper, the seasonal variation characteristics of thermal front, the three-dimensional structure, dynamic characteristics of frontal and mixed characteristics in the shelf sea of eastern Hainan island. It's obviously that the thermal front has a seasonal variation: the front is strongest in winter, and decreased gradually in spring and summer. However, it fade and disappear in fall. The core region of the front also changes with the seasons, it moved southward gradually from mainly distributed in the upwelling zone and the front center is not obvious in summer. it is a typical upwelling front in summer, the near shore is compensated with the underlying low-temperature and high-sale water , while the offshore is the high-temperature and low-salinity shelf water. The thermal front distribution is located in the 100m isobaths. The frontal intensity is reduced with increasing depth, and position goes to offshore. Subsurface temperature front is significantly higher in the surface of the sea, which may cause by the heating of nearshore sea surface water and lead to the weakening horizontal temperature gradient. Dynamic characteristics of the front has a great difference in both sides. The O(1) Rossby number is positive on the dense side and negative on the light side. The maximum of along-frontal velocity is 0.45m/s and the stretching is strengthened by strong horizontal shear, also is the potential vorticity, which can trace the cross front Ekman transport. We obtained the vertical velocity with by quasi-geostrophic omega equation and grasped the ageostrophic secondary circulation. The magnitude of frontal vertical velocity is O(10-5) and causes downwelling on the dense side and upwelling on the light side, which constitute the

  15. Influence of quartz particles on wear in vertical roller mills

    DEFF Research Database (Denmark)

    Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling

    2010-01-01

    The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...... in an increased concentration of abrasive particles in the grinding bed ðR2 > 0:99Þ. The present study shows that the quartz concentration in the grinding bed is determining the wear rate....

  16. Neglected locked vertical patellar dislocation

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Gupta

    2012-01-01

    Full Text Available Patellar dislocations occurring about the vertical and horizontal axis are rare and irreducible. The neglected patellar dislocation is still rarer. We describe the clinical presentation and management of a case of neglected vertical patellar dislocation in a 6 year-old boy who sustained an external rotational strain with a laterally directed force to his knee. Initially the diagnosis was missed and 2 months later open reduction was done. The increased tension generated by the rotation of the lateral extensor retinaculum kept the patella locked in the lateral gutter even with the knee in full extension. Traumatic patellar dislocation with rotation around a vertical axis has been described earlier, but no such neglected case has been reported to the best of our knowledge.

  17. Vertical distribution of the sound-scattering layer in the Amundsen Sea, Antarctica

    Science.gov (United States)

    Lee, Hyungbeen; La, Hyoung Sul; Kang, Donhyug; Lee, SangHoon

    2018-03-01

    Mid-trophic level at high-latitude coastal water in the Southern Ocean reside unique geographical condition with sea ice, coastal polynya, and ice shelf. To investigate the regional differences in their vertical distribution during summer, we examined acoustic backscatter data from scientific echo sounder, collected in the three representative regions in the Amundsen Sea: pack ice zone, coastal polynya zone, and ice shelf zone. The weighted mean depths (WMDs) representing zooplankton were calculated with the high resolution acoustic backscatter (1-m depth) to identify the vertical variability of the sound-scattering layer (SSL). WMDs were mainly distributed between 50 and 130 m exhibiting clear regional differences. The WMDs were detected in the shallow depth ranged between 48 and 84 m within the pack ice and coastal polynya, whereas they were observed at deeper depths around near ice shelf ranged between 117 and 126 m. WMDs varied with changing the stratification of water column structure representing strong linear relationship with the mixed layer depth (r = 0.69). This finding implies that understanding the essential forcing of zooplankton behavior will improve our ability to assess the coastal ecosystem in the Southern Ocean facing dramatic change.

  18. Photo polymerization-induced vertical phase separation and homeotropic alignment in liquid crystal and polymer mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyo [Samsung Advanced Institute of Technology, Yongin (Korea, Republic of); Joo, Sangwoo; Kang, Daeseung [Soongsil Univ., Seoul (Korea, Republic of)

    2012-04-15

    We presented a novel method for the homeotropic alignment of LC by using the irradiation of UV light on the LC/NOA65 mixture cell, in which the photo-initiated-polymerization-induced phase separation lowers the surface energy. When the amount of polymer content is sufficiently small, the gravel and network patterns were formed at the substrates via the vertical phase separation. We found that surface roughness plays an important role in the formation of the homeotropic alignment of LC. We also observed the alignment transition of the cells by varying the mixing ratio of LC/NOA65 or the UV radiation time. Furthermore, the present proposed method has great potential for application in display devices. For decades, studies on the alignment of liquid crystal (LC) molecules have been of significant interest due to their immediate applications for display devices and the intriguing physiochemical properties they exhibit at the surface of mixtures. Usually, homeotropic (or vertical) alignment, in which the long axes of the LC molecules are oriented in a direction perpendicular to the surface, is achieved by using surfactants such as lecithin, silanes or polyimide. Recently homeotropic alignment of liquid crystal molecules was achieved by irradiating photosensitive polymers, by doping nanoparticles into LC, by utilizing nano/micro patterns, or by incorporating self-assembled monolayers (SAMs). However, a clear understanding about the alignment mechanism is still elusive. In this paper, we report a novel method for homeotropic alignment of LC by utilizing the phase separation of LC/polymer mixtures.

  19. Photo polymerization-induced vertical phase separation and homeotropic alignment in liquid crystal and polymer mixtures

    International Nuclear Information System (INIS)

    Kang, Hyo; Joo, Sangwoo; Kang, Daeseung

    2012-01-01

    We presented a novel method for the homeotropic alignment of LC by using the irradiation of UV light on the LC/NOA65 mixture cell, in which the photo-initiated-polymerization-induced phase separation lowers the surface energy. When the amount of polymer content is sufficiently small, the gravel and network patterns were formed at the substrates via the vertical phase separation. We found that surface roughness plays an important role in the formation of the homeotropic alignment of LC. We also observed the alignment transition of the cells by varying the mixing ratio of LC/NOA65 or the UV radiation time. Furthermore, the present proposed method has great potential for application in display devices. For decades, studies on the alignment of liquid crystal (LC) molecules have been of significant interest due to their immediate applications for display devices and the intriguing physiochemical properties they exhibit at the surface of mixtures. Usually, homeotropic (or vertical) alignment, in which the long axes of the LC molecules are oriented in a direction perpendicular to the surface, is achieved by using surfactants such as lecithin, silanes or polyimide. Recently homeotropic alignment of liquid crystal molecules was achieved by irradiating photosensitive polymers, by doping nanoparticles into LC, by utilizing nano/micro patterns, or by incorporating self-assembled monolayers (SAMs). However, a clear understanding about the alignment mechanism is still elusive. In this paper, we report a novel method for homeotropic alignment of LC by utilizing the phase separation of LC/polymer mixtures

  20. Impact of different vertical transport representations on simulating processes in the tropical tropopause layer (TTL)

    Energy Technology Data Exchange (ETDEWEB)

    Ploeger, Felix

    2011-07-06

    The chemical and dynamical processes in the tropical tropopause layer (TTL) control the amount of radiatively active species like water vapour and ozone in the stratosphere, and hence turn out to be crucial for atmospheric trends and climate change. Chemistry transport models and chemistry climate models are suitable tools to understand these processes. But model results are subject to uncertainties arising from the parametrization of model physics. In this thesis the sensitivity of model predictions to the choice of the vertical transport representation will be analysed. Therefore, backtrajectories are calculated in the TTL, based on different diabatic and kinematic transport representations using ERA-Interim and operational ECMWF data. For diabatic transport on potential temperature levels, the vertical velocity is deduced from the ERA-Interim diabatic heat budget. For kinematic transport on pressure levels, the vertical wind is used as vertical velocity. It is found that all terms in the diabatic heat budget are necessary to cause transport from the troposphere to the stratosphere. In particular, clear-sky heating rates alone miss very important processes. Many characteristics of transport in the TTL turn out to depend very sensitively on the choice of the vertical transport representation. Timescales for tropical troposphere-to-stratosphere transport vary between one and three months, with respect to the chosen representation. Moreover, for diabatic transport ascent is found throughout the upper TTL, whereas for kinematic transport regions of mean subsidence occur, particularly above the maritime continent. To investigate the sensitivity of simulated trace gas distributions in the TTL to the transport representation, a conceptual approach is presented to predict water vapour and ozone concentrations from backtrajectories, based on instantaneous freeze-drying and photochemical ozone production. It turns out that ozone predictions and vertical dispersion of the

  1. Experiments in mixed reality

    Science.gov (United States)

    Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

    2010-01-01

    As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

  2. Vertical dimension of occlusion in implant dentistry: significance and approach.

    Science.gov (United States)

    Gittelson, Glenn L

    2002-01-01

    Understanding the principles of occlusion as they relate to managing bite forces on implants is extremely important to maintain the longevity of dental implant prostheses. Specifically, altering vertical dimension of occlusion (VDO) scientifically and predictably is critical to the creation of proper tooth form and guidance when fabricating a full-arch implant-supported prosthesis.

  3. Hybrid Vertical-Cavity Laser

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a light source (2) for light circuits on a silicon platform (3). A vertical laser cavity is formed by a gain region (101) arranged between a top mirror (4) and a bottom grating-mirror (12) in a grating region (11) in a silicon layer (10) on a substrate. A waveguide ...

  4. Esthetic factors of smile in vertical dimensions: A comparative evaluation

    Directory of Open Access Journals (Sweden)

    Divyaroop Rai

    2015-01-01

    Full Text Available Introduction: The variations in aesthetic perception among the professionals and the laypersons were compared, to understand the association of various skeletal and dental factors in vertical dimension, which alter the soft-tissue characteristics during posed/social smile, among young adults. Methods: Images of the posed smile were captured with a digital camera from the 60 nonorthodontic treated young adults (30 girls, 30 boys. Determinants of the "pleasing smile" were identified from the results of a Visual Analog Scale. Quantitative measurements of the soft- and hard-tissue were made by using the smile images and cephalometric radiographs. The esthetics of the smile was correlated with specific skeletal, dental, and soft-tissue structures in the anteroposterior and vertical dimensions. Results: Three factors formed significant components of a pleasant smile, for orthodontists (incisogingival display, upper lip, and buccal corridor and three for laypersons (upper lip, lower lip, and smile arc. A strong positive correlation was seen among skeletal and dental vertical dimensions and incisor show. The vertical thickness of the upper lip had a significant positive correlation with the position of the maxillary incisor. Conclusion: Incisogingival display, upper lip, lower lip and buccal corridor proved to be the most influential variables in smile esthetics. The significant relationship of incisor protrusion with the vertical thickness of the vermilion border of the upper lip shows that skeletal and dental vertical dimensions for incisal display must be considered when planning orthodontic treatment.

  5. Mixed cryoglobulinemia

    Directory of Open Access Journals (Sweden)

    Ferri Clodoveo

    2008-09-01

    Full Text Available Abstract Mixed cryoglobulinemia (MC, type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1, but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers, chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome

  6. Influence of clogging and resting processes on flow patterns in vertical flow constructed wetlands.

    Science.gov (United States)

    Hua, Guofen; Kong, Jun; Ji, Yuyu; Li, Man

    2018-04-15

    Vertical flow constructed wetlands are widely used for removing pollutants from wastewater. Substrate clogging is an operational challenge of constructed wetlands, which can result in impeded water flow and finally a significant decline in the ability of the system to treat the wastewater. The entire clogging process in a vertical flow constructed wetland (VFCW) was quantitatively analyzed by measurements of hydraulic conductivity. Tracer tests and model simulations were carried out to investigate internal flow patterns during the clogging and resting processes. This analysis revealed that hydraulic conductivity gradually decreased with operation time. Further, the distribution time of the flow field was different under different degrees of clogging. Non-uniformity in water flow was primarily observed in the first 400min after adding the tracer (NaCl) in the early clogging stage, as opposed to the last 400min in the late clogging stage. Variation in water flow divergence was closely correlated with piston flow; the reaction efficiency was highest in the early stages of clogging. In the later stages, stronger flow mixing was observed. Resting operations can reduce the dispersion of internal flow and improve reaction efficiency. After resting for approximately 15days, tracer concentration fluctuations decreased and internal flow back-mixing was alleviated. A simulation further described the internal flow pattern and elaborated and validated the tracer experiment. The outcomes of this study will assist in understanding how internal flow behavior varies in response to the clogging process and reveal details of the internal clogging mechanism in VFCWs. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Understanding Carbohydrates

    Science.gov (United States)

    ... Size: A A A Listen En Español Understanding Carbohydrates How much and what type of carbohydrate foods ... glucose levels in your target range. Explore: Understanding Carbohydrates Glycemic Index and Diabetes Learn about the glycemic ...

  8. Intuitive Mechanics: Inferences of Vertical Projectile Motion

    Directory of Open Access Journals (Sweden)

    Milana Damjenić

    2016-07-01

    Full Text Available Our intuitive knowledge of physics mechanics, i.e. knowledge defined through personal experience about velocity, acceleration, motion causes, etc., is often wrong. This research examined whether similar misconceptions occur systematically in the case of vertical projectiles launched upwards. The first experiment examined inferences of velocity and acceleration of the ball moving vertically upwards, while the second experiment examined whether the mass of the thrown ball and force of the throw have an impact on the inference. The results showed that more than three quarters of the participants wrongly assumed that maximum velocity and peak acceleration did not occur at the initial launch of the projectile. There was no effect of object mass or effect of the force of the throw on the inference relating to the velocity and acceleration of the ball. The results exceed the explanatory reach of the impetus theory, most commonly used to explain the naive understanding of the mechanics of object motion. This research supports that the actions on objects approach and the property transmission heuristics may more aptly explain the dissidence between perceived and actual implications in projectile motion.

  9. Granular boycott effect: How to mix granulates

    Science.gov (United States)

    Duran, J.; Mazozi, T.

    1999-11-01

    Granular material can display the basic features of the Boycott effect in sedimentation. A simple experiment shows that granular material falls faster in an inclined tube than in a vertical tube, in analogy with the Boycott effect. As long as the inclination of the tube is above the avalanche threshold, descent of granular material in the tube causes internal convection which in turn results in an efficient mixture of the granular components. By contrast, as in analogous experiments in two dimensions, a vertical fall of granular material occurs via successive block fragmentation, resulting in poor mixing.

  10. Supracardiac total anomalous pulmonary venous connection with a descending vertical vein.

    Science.gov (United States)

    Shah, Sejal; Singh, Mukesh; John, Colin; Maheshwari, Sunita

    2009-10-01

    The commonly used Darling classification for total anomalous pulmonary venous connection (TAPVC) consists of supracardiac, cardiac, infracardiac, and mixed types (Craig et al., Lab Invest 6:44-64, 1967). In supracardiac TAPVC, the common pulmonary vein drains superiorly into the left innominate vein, the superior vena cava, or the azygos vein by way of an ascending vertical vein. We describe a case of supracardiac TAPVC draining into the azygos vein atypically by way of a descending vertical vein.

  11. Assessing and Upgrading Ocean Mixing for the Study of Climate Change

    Science.gov (United States)

    Howard, A. M.; Fells, J.; Lindo, F.; Tulsee, V.; Canuto, V.; Cheng, Y.; Dubovikov, M. S.; Leboissetier, A.

    2016-12-01

    Climate is critical. Climate variability affects us all; Climate Change is a burning issue. Droughts, floods, other extreme events, and Global Warming's effects on these and problems such as sea-level rise and ecosystem disruption threaten lives. Citizens must be informed to make decisions concerning climate such as "business as usual" vs. mitigating emissions to keep warming within bounds. Medgar Evers undergraduates aid NASA research while learning climate science and developing computer&math skills. To make useful predictions we must realistically model each component of the climate system, including the ocean, whose critical role includes transporting&storing heat and dissolved CO2. We need physically based parameterizations of key ocean processes that can't be put explicitly in a global climate model, e.g. vertical&lateral mixing. The NASA-GISS turbulence group uses theory to model mixing including: 1) a comprehensive scheme for small scale vertical mixing, including convection&shear, internal waves & double-diffusion, and bottom tides 2) a new parameterization for the lateral&vertical mixing by mesoscale eddies. For better understanding we write our own programs. To assess the modelling MATLAB programs visualize and calculate statistics, including means, standard deviations and correlations, on NASA-GISS OGCM output with different mixing schemes and help us study drift from observations. We also try to upgrade the schemes, e.g. the bottom tidal mixing parameterizations' roughness, calculated from high resolution topographic data using Gaussian weighting functions with cut-offs. We study the effects of their parameters to improve them. A FORTRAN program extracts topography data subsets of manageable size for a MATLAB program, tested on idealized cases, to visualize&calculate roughness on. Students are introduced to modeling a complex system, gain a deeper appreciation of climate science, programming skills and familiarity with MATLAB, while furthering climate

  12. Kinematic Fitting of Detached Vertices

    Energy Technology Data Exchange (ETDEWEB)

    Mattione, Paul [Rice Univ., Houston, TX (United States)

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  13. INTERNATIONAL SPECIALIZATION AND VERTICAL DIFFERENTIATION

    Directory of Open Access Journals (Sweden)

    Furia Donatella

    2010-07-01

    Full Text Available During the last decades, market segmentation and intra-industry trade have become increasingly relevant. The underlying hypothesis of our work is that distinct articles have heterogeneous potential for vertical differentiation, implying that different patterns of international specialization should be identifiable. We carry out an analysis on revealed comparative advantage (through the Lafay Index in specific sectors of interest. Then we highlight the emergence of diverse degrees of product quality differentiation among sectors (through the Relative Quality Index. Results confirm our hypothesis. Indeed it appears that only certain goods, for which the pace of either creative or technological innovation (or both is particularly fast, present a high degree of vertical differentiation and market segmentation. This allows countries to specialize in a particular product variety and gain market power position for that variety. These findings should be taken in due consideration when designing trade policies.

  14. Vertical seismic response of overhead crane

    International Nuclear Information System (INIS)

    Otani, Akihito; Nagashima, Keisuke; Suzuki, Junya

    2002-01-01

    Vertical seismic response behavior is an important issue for the seismic design of equipments. The equipment, which is comparatively soft and unrestrained vertically, may resonate and its response is significantly magnified under vertical seismic excitation. Overhead crane is an example of equipment that is unrestrained vertically. The dynamic behavior of an 150-ton-capacity overhead crane under vertical seismic excitation was investigated by scale model excitation test and nonlinear time history analysis. The excitation tests were performed with several input levels and the vertical response with each input level was obtained. The simulation analysis approximately corresponded to the results of the excitation test

  15. Coexistence of Strategic Vertical Separation and Integration

    DEFF Research Database (Denmark)

    Jansen, Jos

    2003-01-01

    This paper gives conditions under which vertical separation is chosen by some upstream firms, while vertical integration is chosen by others in the equilibrium of a symmetric model. A vertically separating firm trades off fixed contracting costs against the strategic benefit of writing a (two......-part tariff, exclusive dealing) contract with its retailer. Coexistence emerges when more than two vertical Cournot oligopolists supply close substitutes. When vertical integration and separation coexist, welfare could be improved by reducing the number of vertically separating firms. The scope...

  16. Vertical Launch System Loadout Planner

    Science.gov (United States)

    2015-03-01

    United States Navy USS United States’ Ship VBA Visual Basic for Applications VLP VLS Loadout Planner VLS Vertical Launch System...mathematically complex and require training to operate the software. A Visual Basic for Applications ( VBA ) Excel (Microsoft Corporation, 2015...lockheed/data/ms2/documents/laun chers/MK41 VLS factsheet.pdf Microsoft Excel version 14.4.3, VBA computer software. (2011). Redmond, WA: Microsoft

  17. Strategic Inventories in Vertical Contracts

    OpenAIRE

    Krishnan Anand; Ravi Anupindi; Yehuda Bassok

    2008-01-01

    Classical reasons for carrying inventory include fixed (nonlinear) production or procurement costs, lead times, nonstationary or uncertain supply/demand, and capacity constraints. The last decade has seen active research in supply chain coordination focusing on the role of incentive contracts to achieve first-best levels of inventory. An extensive literature in industrial organization that studies incentives for vertical controls largely ignores the effect of inventories. Does the ability to ...

  18. Poligonación Vertical

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

    Full Text Available La poligonación vertical es un método de medición de diferencias de altura que aprovecha las posibilidades de las estaciones totales. Se presta fundamentalmente para líneas de nivelación entre nodos formando red. El nombre se debe a que las visuales sucesivas se proyectan sobre aristas verticales en lugar de un plano horizontal, como ocurre en la poligonación convencional.

  19. NASA-Ames vertical gun

    Science.gov (United States)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  20. vertical conveyor as Wood construction

    OpenAIRE

    Kluge, Patrick; Penno, Eric; Eichhorn, Sven; Müller, Christoph

    2017-01-01

    Es wird aufbauend auf einen Vertikalförderer in Metallbauweise die konstruktive Umsetzung eines Vertikalförderers in Holzbauweise beschrieben und dessen Schwingungs- und Auslenkungsverhalten in labormäßigen Untersuchungen analysiert und bewertet. Ein Vergleich der Holz- und Metallbauweise hinsichtlich technischer (Gewicht), ökonomischer (Kosten) und ökologischer Kriterien Primärenergiebedarf, Treibhauspotential) ordnet die Holzbauweise in den Stand der Technik ein. Based on a vertical c...

  1. Prophylaxis of vertical HBV infection.

    Science.gov (United States)

    Pawlowska, Malgorzata; Pniewska, Anna; Pilarczyk, Malgorzata; Kozielewicz, Dorota; Domagalski, Krzysztof

    2016-10-01

    An appropriate management of HBV infection is the best strategy to finally reduce the total burden of HBV infection. Mother-to-child transmission (MTCT) is responsible for more than one third of chronic HBV infections worldwide. Because HBV infection in infancy or early childhood often leads to chronic infection, appropriate prophylaxis and management of HBV in pregnancy is crucial to prevent MTCT. The prevention of HBV vertical transmission is a complex task and includes: universal HBV screening of pregnant women, administration of antivirals in the third trimester of pregnancy in women with high viral load and passive-active HBV immunoprophylaxis with hepatitis B vaccine and hepatitis B immune globulin in newborns of all HBV infected women. Universal screening of pregnant women for HBV infection, early identification of HBV DNA level in HBV-infected mothers, maternal treatment with class B according to FDA antivirals and passive/active anti-HBV immunoprophylaxis to newborns of HBV-positive mothers are crucial strategies for reducing vertical HBV transmission rates. Consideration of caesarean section in order to reduce the risk of vertical HBV transmission should be recommend in HBV infected pregnant women with high viral load despite antiviral therapy or when the therapy in the third trimester of pregnancy is not available.

  2. Mixing of solids

    CERN Document Server

    Weinekötter, Ralf

    2000-01-01

    This book is a welcome edition to the Particle Technology Series, formerly Powder Technology Series. It is the second book in the series which describes powder mixing and we make no excuses for that. The topic of powder mixing is fundamental to powder technology and is one which always aroses interest. That will not change. As powder products become more complex they will pose new mixing problems. The solutions lie in the intelligent use of equipment, an understanding of powder properties and a good knowledge of basic statistics. The authors of this book have presented those three ingredients with great clarity. The book is based on long experience and deep thought, I have enjoyed reading it and am pleased to recommend it. Delft University of Technology, NL-Delft, July 1999 Brian Scarlett, Series Editor IX VII Foreword to the English Edition In response to many enquiries from industrial organisations and institutes involved with the technology of processing bulk materials, we are pleased to present the Englis...

  3. Glacier winds in the Rongbuk Valley, north of Mount Everest: 2. Their role in vertical exchange processes

    Science.gov (United States)

    Cai, Xuhui; Song, Yu; Zhu, Tong; Lin, Weili; Kang, Ling

    2007-06-01

    High ozone concentrations, combined with low humidity and strong, persistent glacier winds, were found at the surface of Rongbuk Valley, north of Mount Everest, with sharply increased ozone concentrations in their vertical profiles. Glacier winds and their roles in vertical exchange of the atmosphere were investigated numerically to understand the phenomena. A Lagrangian particle dispersion model was used to carry out numerical experiments (forward-in-time simulations) and footprint analysis (backward-in-time simulations). The meteorological data inputs for these experiments were derived from the Advanced Regional Prediction System. Results showed that glacier winds may lead to significant downward transport of 1.5-2 km during the daytime from the northern slopes of Mount Everest. Glacier winds could advance down through the valley, with strong upward motions shown as a rolling up in front of their leading edge. Combining with upslope winds at two sidewalls of the valley or up-valley winds of tributaries, the lifting flows produced strong mixing of the atmosphere to a depth of approximately 3 km. Three-dimensional footprints derived from the particle dispersion model for the observational site, Rongbuk Monastery, clearly show influence from the mountainside of Mount Everest and from the southern part of the valley. The vertical extension of influence was as much as 2-3 km. Good correlation was found between the influence height and the ozone concentration. All the simulation results strongly indicate that the glacier winds and their related vertical exchange processes "pump down" ozone-rich air from upper levels to the surface of the valley.

  4. Efficient Extraction of High Centrality Vertices in Distributed Graphs

    Energy Technology Data Exchange (ETDEWEB)

    Kumbhare, Alok [Univ. of Southern California, Los Angeles, CA (United States); Frincu, Marc [Univ. of Southern California, Los Angeles, CA (United States); Raghavendra, Cauligi S. [Univ. of Southern California, Los Angeles, CA (United States); Prasanna, Viktor K. [Univ. of Southern California, Los Angeles, CA (United States)

    2014-09-09

    Betweenness centrality (BC) is an important measure for identifying high value or critical vertices in graphs, in variety of domains such as communication networks, road networks, and social graphs. However, calculating betweenness values is prohibitively expensive and, more often, domain experts are interested only in the vertices with the highest centrality values. In this paper, we first propose a partition-centric algorithm (MS-BC) to calculate BC for a large distributed graph that optimizes resource utilization and improves overall performance. Further, we extend the notion of approximate BC by pruning the graph and removing a subset of edges and vertices that contribute the least to the betweenness values of other vertices (MSL-BC), which further improves the runtime performance. We evaluate the proposed algorithms using a mix of real-world and synthetic graphs on an HPC cluster and analyze its strengths and weaknesses. The experimental results show an improvement in performance of upto 12x for large sparse graphs as compared to the state-of-the-art, and at the same time highlights the need for better partitioning methods to enable a balanced workload across partitions for unbalanced graphs such as small-world or power-law graphs.

  5. How does tooth eruption relate to vertical mandibular growth displacement?

    Science.gov (United States)

    Liu, Sean Shih-Yao; Buschang, Peter H

    2011-06-01

    Our objectives were to investigate the eruptive patterns of the mandibular teeth and assess their associations with mandibular growth displacements. Cephalograms for a mixed-longitudinal sample of 124 French-Canadian girls were evaluated between 10 and 15 years of age. Vertical mandibular displacement and mandibular eruption were evaluated by using cranial and mandibular superimpositions, respectively. Multilevel modeling procedures were used to estimate each subject's growth change over time. Stepwise multiple regressions were used to determine the amount and relative magnitudes of variations in mandibular eruption explained by mandibular growth displacement, controlling for vertical maxillary tooth movements. Cubic polynomial models explained between 91% and 98% of the variations in eruption and vertical growth displacement. All curves showed acceleration of eruption until approximately 12 years of age, after which eruption decelerated. The eruption of the mandibular teeth demonstrated greater relative variability than did vertical mandibular growth displacements. Independent of the overall movements of the maxillary molars, inferior mandibular growth displacement explained approximately 54% of the variation in mandibular molar eruption between 10.5 and 14.5 years of age. Inferior mandibular growth displacement and dental eruption followed similar patterns of change during adolescence. Based on their associations and the differences in variability identified, mandibular eruption appears to compensate for or adapt to growth displacements. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  6. A compact dilution refrigerator with vertical heat exchangers for operation to 2 mK

    International Nuclear Information System (INIS)

    Bunkov, Yu.M.; Guenault, A.M.; Hayward, D.J.; Jackson, D.A.; Kennedy, C.J.; Nichols, T.R.; Miller, I.E.; Pickett, G.R.; Ward, M.G.

    1991-01-01

    A compactly designed dilution refrigerator with closely packed, vertical heat exchangers is described. The refrigerator reaches a temperature of 2 mK and is easily constructed, since the sintered heat exchangers are straight units. Vibrating wire resonators are employed in the mixing chamber as diagnostic tools, which may act as both thermometers and phase-boundary level indicators. There is a design problem in the vertical arrangement, namely, the sumps on the concentrated phase side that can slowly fill with dilute phase and degrade the performance. The problem is solved by draining the superfluid 4 He component in any collected dilute phase through superleaks into the mixing chamber

  7. Cephalometric approach to the occlusal vertical dimension reestablishment.

    Science.gov (United States)

    Zielak, João César; Gulin Neto, David; da Cunha, Leonardo Fernandes; Deliberador, Tatiana Miranda; Giovanini, Allan Fernando

    2014-01-01

    The occlusal vertical dimension (OVD) refers to the length of the face as determined by the amount of separation of the jaws. Its determination is important for the manufacture of restorations. However, defining the correct occlusal vertical dimension for edentulous patients is one of the most important steps for function and esthetics rehabilitation. Cephalometry is a standardized method of assessing dental and facial proportions and their interrelation. Additionally, cephalometric analysis of the facial vertical dimension can establish an individual pattern for each patient. This analysis should become a permanent part of each patient's record. Hence, this study presented a case report with the use of cephalometry as an auxiliary tool in the rehabilitation of OVD. Clinical relevance showed that cephalometric analysis can be an accurate and convenient instrument to treatment planning and prognostic of oral rehabilitation. The reader should understand the clinical implications of using cephalometry as a tool in the rehabilitation of OVD.

  8. Cephalometric Approach to the Occlusal Vertical Dimension Reestablishment

    Directory of Open Access Journals (Sweden)

    João César Zielak

    2014-01-01

    Full Text Available The occlusal vertical dimension (OVD refers to the length of the face as determined by the amount of separation of the jaws. Its determination is important for the manufacture of restorations. However, defining the correct occlusal vertical dimension for edentulous patients is one of the most important steps for function and esthetics rehabilitation. Cephalometry is a standardized method of assessing dental and facial proportions and their interrelation. Additionally, cephalometric analysis of the facial vertical dimension can establish an individual pattern for each patient. This analysis should become a permanent part of each patient’s record. Hence, this study presented a case report with the use of cephalometry as an auxiliary tool in the rehabilitation of OVD. Clinical relevance showed that cephalometric analysis can be an accurate and convenient instrument to treatment planning and prognostic of oral rehabilitation. The reader should understand the clinical implications of using cephalometry as a tool in the rehabilitation of OVD.

  9. [Vertical fractures: apropos of 2 clinical cases].

    Science.gov (United States)

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures.

  10. Scanning vertical distributions of typical aerosols along the Yangtze River using elastic lidar.

    Science.gov (United States)

    Fan, Shidong; Liu, Cheng; Xie, Zhouqing; Dong, Yunsheng; Hu, Qihou; Fan, Guangqiang; Chen, Zhengyi; Zhang, Tianshu; Duan, Jingbo; Zhang, Pengfei; Liu, Jianguo

    2018-02-14

    In recent years, China has experienced heavy air pollution, especially haze caused by particulate matter (PM). The compositions, horizontal distributions, transport, and chemical formation mechanisms of PM and its precursors have been widely investigated in China based on near-ground measurements. However, the understanding of the distributions and physical and chemical processes of PM in the vertical direction remains limited. In this study, an elastic lidar was employed to investigate the vertical profiles of aerosols along the Yangtze River during the Yangtze River Campaign of winter 2015. Some typical aerosols were identified and some events were analyzed in three cases. Dust aerosols can be transported from the Gobi Desert to the Yangtze River basin across a long distance at both low and high altitudes in early December. The transport route was perpendicular to the ship track, suggesting that the dust aerosols may have affected a large area. Moreover, during transport, some dust was also affected by the areas below its transport route since some anthropogenic pollutants were mixed with the dust and changed some of its optical properties. Biomass-burning aerosols covering a distant range along the Yangtze River were identified. This result directly shows the impact areas of biomass-burning aerosols in some agricultural fields. Some directly emitted aerosol plumes were observed, and direct effects of such plumes were limited both temporally and spatially. In addition, an aerosol plume with very low linear depolarization ratios, probably formed through secondary processes, was also observed. These results can help us better understand aerosols in large spatial scales in China and can be useful to regional haze studies. Copyright © 2018. Published by Elsevier B.V.

  11. Determinations of vertical stroke V{sub cb} vertical stroke and vertical stroke V{sub ub} vertical stroke from baryonic Λ{sub b} decays

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Y.K. [Shanxi Normal University, School of Physics and Information Engineering, Linfen (China); National Tsing Hua University, Department of Physics, Hsinchu (China); Geng, C.Q. [Shanxi Normal University, School of Physics and Information Engineering, Linfen (China); National Tsing Hua University, Department of Physics, Hsinchu (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Changsha (China)

    2017-10-15

    We present the first attempt to extract vertical stroke V{sub cb} vertical stroke from the Λ{sub b} → Λ{sub c}{sup +}l anti ν{sub l} decay without relying on vertical stroke V{sub ub} vertical stroke inputs from the B meson decays. Meanwhile, the hadronic Λ{sub b} → Λ{sub c}M{sub (c)} decays with M = (π{sup -},K{sup -}) and M{sub c} =(D{sup -},D{sup -}{sub s}) measured with high precisions are involved in the extraction. Explicitly, we find that vertical stroke V{sub cb} vertical stroke =(44.6 ± 3.2) x 10{sup -3}, agreeing with the value of (42.11 ± 0.74) x 10{sup -3} from the inclusive B → X{sub c}l anti ν{sub l} decays. Furthermore, based on the most recent ratio of vertical stroke V{sub ub} vertical stroke / vertical stroke V{sub cb} vertical stroke from the exclusive modes, we obtain vertical stroke V{sub ub} vertical stroke = (4.3 ± 0.4) x 10{sup -3}, which is close to the value of (4.49 ± 0.24) x 10{sup -3} from the inclusive B → X{sub u}l anti ν{sub l} decays. We conclude that our determinations of vertical stroke V{sub cb} vertical stroke and vertical stroke V{sub ub} vertical stroke favor the corresponding inclusive extractions in the B decays. (orig.)

  12. Transverse vertical dispersion in groundwater and the capillary fringe.

    Science.gov (United States)

    Klenk, I D; Grathwohl, P

    2002-09-01

    Transverse dispersion is the most relevant process in mass transfer of contaminants across the capillary fringe (both directions), dilution of contaminants, and mixing of electron acceptors and electron donors in biodegrading groundwater plumes. This paper gives an overview on literature values of transverse vertical dispersivities alpha(tv) measured at different flow velocities and compares them to results from well-controlled laboratory-tank experiments on mass transfer of trichloroethene (TCE) across the capillary fringe. The measured values of transverse vertical dispersion in the capillary fringe region were larger than in fully saturated media, which is credited to enhanced tortuosity of the flow paths due to entrapped air within the capillary fringe. In all cases, the values observed for alpha(tv) were < 1 mm. The new measurements and the literature values indicate that alpha(tv) apparently declines with increasing flow velocity. The latter is attributed to incomplete diffusive mixing at the pore scale (pore throats). A simple conceptual model, based on the mean square displacement and the pore size accounting for only partial diffusive mixing at increasing flow velocities, shows very good agreement with measured and published data.

  13. Understanding classification

    NARCIS (Netherlands)

    Subianto, M.

    2009-01-01

    In practical data analysis, the understandability of models plays an important role in their acceptance. In the data mining literature, however, understandability plays is hardly ever mentioned. If it is mentioned, it is interpreted as meaning that the models have to be simple. In this thesis we

  14. Turbulent mixing and entrainment in a gravity current

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory; Odier, Philippe [ENS-LYON, FRANCE; Chen, Jun [PURDUE UNIV.

    2010-01-01

    We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadratically with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing lenth, approximately constant over the mixing zone of the stratified shear layer. We show how, in different flow configurations, this length can be related to the shear length of the flow ({var_epsilon}/{partial_derivative}{sub z}u{sup 3}){sup 1/2}. We also study the fluctuations of the momentum and density turbulent fluxes, showing how they relate to the mixing phenomena, and to the entrainment/detrainment balance.

  15. Optimal Control of Vertically Transmitted Disease: An Integrated Approach

    Directory of Open Access Journals (Sweden)

    Samit Bhattacharyya

    2010-01-01

    horizontal transmission, administration of the antiviral drug to infected individuals lessens the chance of vertical transmission. Thus the vaccine and antiviral drug play different roles in controlling the disease, which has both vertical and horizontal transmission. We develop a 3D model with Susceptible–Infected–Recovered under vaccination to the susceptible and antiviral treatment to the infected and consider a control theoretic approach using the Pontryagin maximum principle to analyse the costeffectiveness of the control process. Our results demonstrate that a mixed intervention strategy of vaccination and antiviral drug in a proper ratio is the most effective way to control the disease. We show that cost-effectiveness of both intervention strategies intimately depends on disease-related parameters, such as force of infection, probability of being infected to offspring from infected mothers, loss of immunity or reinfection and also on cost of treatment.

  16. Is Convection Sensitive to Model Vertical Resolution and Why?

    Science.gov (United States)

    Xie, S.; Lin, W.; Zhang, G. J.

    2017-12-01

    Model sensitivity to horizontal resolutions has been studied extensively, whereas model sensitivity to vertical resolution is much less explored. In this study, we use the US Department of Energy (DOE)'s Accelerated Climate Modeling for Energy (ACME) atmosphere model to examine the sensitivity of clouds and precipitation to the increase of vertical resolution of the model. We attempt to understand what results in the behavior change (if any) of convective processes represented by the unified shallow and turbulent scheme named CLUBB (Cloud Layers Unified by Binormals) and the Zhang-McFarlane deep convection scheme in ACME. A short-term hindcast approach is used to isolate parameterization issues from the large-scale circulation. The analysis emphasizes on how the change of vertical resolution could affect precipitation partitioning between convective- and grid-scale as well as the vertical profiles of convection-related quantities such as temperature, humidity, clouds, convective heating and drying, and entrainment and detrainment. The goal is to provide physical insight into potential issues with model convective processes associated with the increase of model vertical resolution. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. Embodied understanding.

    Science.gov (United States)

    Johnson, Mark

    2015-01-01

    Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

  18. Metal Oxide Vertical Graphene Hybrid Supercapacitors

    Science.gov (United States)

    Meyyappan, Meyya (Inventor)

    2018-01-01

    A metal oxide vertical graphene hybrid supercapacitor is provided. The supercapacitor includes a pair of collectors facing each other, and vertical graphene electrode material grown directly on each of the pair of collectors without catalyst or binders. A separator may separate the vertical graphene electrode materials.

  19. The effect of concrete vertical construction joints on the modulus of rupture

    Directory of Open Access Journals (Sweden)

    Camille A. Issa

    2014-01-01

    In this study, seven different concrete mix designs were used. From each concrete mix, six plain concrete beams were poured, half of which were monolithic and the other half with a vertical construction joint at the beam center. Four cylinders per design mix were casted for the purpose of obtaining the mix compressive strength. The experimental results indicate that for monolithic beams, the ACI Code always underestimates the modulus of rupture, whereas in the presence of a vertical construction joint, the conducted experiments yield a significant loss in the modulus of rupture of concrete that varies between 24% and 83%. Thus, there is a clear justification for providing dowels at construction joints in order to assure continuity in strength over joints in plain concrete.

  20. A Remote Sensing Approach to Estimate Vertical Profile Classes of Phytoplankton in a Eutrophic Lake

    Directory of Open Access Journals (Sweden)

    Kun Xue

    2015-10-01

    Full Text Available The extension and frequency of algal blooms in surface waters can be monitored using remote sensing techniques, yet knowledge of their vertical distribution is fundamental to determine total phytoplankton biomass and understanding temporal variability of surface conditions and the underwater light field. However, different vertical distribution classes of phytoplankton may occur in complex inland lakes. Identification of the vertical profile classes of phytoplankton becomes the key and first step to estimate its vertical profile. The vertical distribution profile of phytoplankton is based on a weighted integral of reflected light from all depths and is difficult to determine by reflectance data alone. In this study, four Chla vertical profile classes (vertically uniform, Gaussian, exponential and hyperbolic were found to occur in three in situ vertical surveys (28 May, 19–24 July and 10–12 October in a shallow eutrophic lake, Lake Chaohu. We developed and validated a classification and regression tree (CART to determine vertical phytoplankton biomass profile classes. This was based on an algal bloom index (Normalized Difference algal Bloom Index, NDBI applied to both in situ remote sensing reflectance (Rrs and MODIS Rayleigh-corrected reflectance (Rrc data in combination with data of local wind speed. The results show the potential of retrieving Chla vertical profiles information from integrated information sources following a decision tree approach.

  1. Cumulus cloud venting of mixed layer ozone

    Science.gov (United States)

    Ching, J. K. S.; Shipley, S. T.; Browell, E. V.; Brewer, D. A.

    1985-01-01

    Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosols occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. The experiments utilized the airborne Ultra-Violet Differential Absorption Lidar (UV-DIAL) system. This system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Evening transects were obtained in the downwind area where the air mass had been advected. Space-height analyses for the evening flight show the cloud debris as patterns of ozone typically in excess of the ambient free tropospheric background. This ozone excess was approximately the value of the concentration difference between the mixed layer and free troposphere determined from independent vertical soundings made by another aircraft in the afternoon.

  2. Radiology of vertical banded gastroplasty

    International Nuclear Information System (INIS)

    Leekam, R.N.; Deitel, M.; Shankar, L.; Salsberg, B.

    1987-01-01

    Vertical banded gastroplasty is now the most common procedure for the surgical treatment of obesity. In the past 4 years 120 patients have been referred for radiologic examination. This exhibit describes the normal and abnormal findings in many of these patients. The authors divided radiologic abnormalities into three groups: abnormalities of the partition, abnormalities of the banded channel, and ulcers and extragastric leaks. The authors' examination technique has been adapted from those described by others, our important addition being the preliminary precontrast film, on which the staple lines can be examined. This has proved most effective in the detection of partition defects

  3. Surface wind mixing in the Regional Ocean Modeling System (ROMS)

    Science.gov (United States)

    Robertson, Robin; Hartlipp, Paul

    2017-12-01

    Mixing at the ocean surface is key for atmosphere-ocean interactions and the distribution of heat, energy, and gases in the upper ocean. Winds are the primary force for surface mixing. To properly simulate upper ocean dynamics and the flux of these quantities within the upper ocean, models must reproduce mixing in the upper ocean. To evaluate the performance of the Regional Ocean Modeling System (ROMS) in replicating the surface mixing, the results of four different vertical mixing parameterizations were compared against observations, using the surface mixed layer depth, the temperature fields, and observed diffusivities for comparisons. The vertical mixing parameterizations investigated were Mellor- Yamada 2.5 level turbulent closure (MY), Large- McWilliams- Doney Kpp (LMD), Nakanishi- Niino (NN), and the generic length scale (GLS) schemes. This was done for one temperate site in deep water in the Eastern Pacific and three shallow water sites in the Baltic Sea. The model reproduced the surface mixed layer depth reasonably well for all sites; however, the temperature fields were reproduced well for the deep site, but not for the shallow Baltic Sea sites. In the Baltic Sea, the models overmixed the water column after a few days. Vertical temperature diffusivities were higher than those observed and did not show the temporal fluctuations present in the observations. The best performance was by NN and MY; however, MY became unstable in two of the shallow simulations with high winds. The performance of GLS nearly as good as NN and MY. LMD had the poorest performance as it generated temperature diffusivities that were too high and induced too much mixing. Further observational comparisons are needed to evaluate the effects of different stratification and wind conditions and the limitations on the vertical mixing parameterizations.

  4. Scoping Study of Airlift Circulation Technologies for Supplemental Mixing in Pulse Jet Mixed Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Berglin, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Boeringa, Gregory K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buchmiller, William C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burns, Carolyn A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-07

    At the request of the U.S. Department of Energy Office of River Protection, Pacific Northwest National Laboratory (PNNL) conducted a scoping study to investigate supplemental technologies for supplying vertical fluid motion and enhanced mixing in Waste Treatment and Immobilization Plant (WTP) vessels designed for high solids processing. The study assumed that the pulse jet mixers adequately mix and shear the bottom portion of a vessel. Given that, the primary function of a supplemental technology should be to provide mixing and shearing in the upper region of a vessel. The objective of the study was to recommend a mixing technology and configuration that could be implemented in the 8-ft test vessel located at Mid-Columbia Engineering (MCE). Several mixing technologies, primarily airlift circulator (ALC) systems, were evaluated in the study. This technical report contains a review of ALC technologies, a description of the PNNL testing and accompanying results, and recommended features of an ALC system for further study.

  5. Environmental drivers of vertical distribution in diapausing Calanus copepods in the Northwest Atlantic

    Science.gov (United States)

    Krumhansl, Kira A.; Head, Erica J. H.; Pepin, Pierre; Plourde, Stéphane; Record, Nicholas R.; Runge, Jeffrey A.; Johnson, Catherine L.

    2018-03-01

    Copepods of the genus Calanus play a critical trophic role in the North Atlantic ecosystems, where they serve as an important source of energy-rich food for fish and marine mammals, including the endangered North Atlantic right whale. As a strategy for coping with unfavorable near-surface conditions, Calanus enter diapause and migrate to deep water in late summer and fall after feeding and accumulating lipid stores in spring and summer. In order to assess the most important physical drivers of vertical distribution of diapausing Calanus, we synthesized existing depth-stratified abundance data of Calanus finmarchicus and Calanus hyperboreus from the Northwest Atlantic continental shelf and slope regions, spanning Newfoundland in the northeast to the Gulf of Maine in the southwest. Bottom depth strongly constrained the depth and shape of vertical distributions, with distributions becoming deeper and less compact as bottom depth increased. Diapausing Calanus, observed across a broad range of temperature (T) and in-situ density (σ) conditions (T = -1.0 to 14.4 °C, σ = 25.3-28.1 kg m-3), tended to distribute at depths with the coldest temperatures locally available. Over the shelf, diapausing Calanus in the GOM and SS generally did not have access to temperatures considered optimal for diapause (<5 °C), in many cases occurring at temperatures well above this threshold. Diapausing Calanus in both habitats were most commonly below the Cold Intermediate Layer (CIL), a feature formed through wind-driven mixing during the winter, but this effect was more obvious over the shelf than in slope waters. Our analysis highlights key differences in the vertical distributions of diapausing Calanus over the shelf vs. the slope, having regional implications for ecological dynamics and population persistence in the face of warming temperatures. In general, understanding factors that influence vertical distributions of diapausing Calanus will allow us to more accurately predict how

  6. DEM Simulations of Granular Secondary Flow in Cylindrical Vertical Bladed Mixer – Effect of Blade Rake.

    OpenAIRE

    Trávníčková, T. (Tereza); Havlica, J. (Jaromír); Kohout, M.

    2016-01-01

    Mixing of granular systems is one of the most used chemical engineering unit operations. However, detailed description of the dynamics of granular flows through experiments is difficult. Therefore, usage of mathematical modeling increases. In this paper we deal with DEM (Discreet Element Method) simulations of mixing glass beads in a cylindrical vertical bladed mixer. The aim of this work is to describe the influence of blade rake on the development of granular secondary flows for different s...

  7. Kelvin-Helmholtz instability with mixing zone

    International Nuclear Information System (INIS)

    Chong-Techer, R.

    2008-01-01

    This thesis is part of the FATHER experiment and the analyze of the hydrodynamical instabilities which appear during the mixing of two liquids of same volume mass with shearing speed in the mixing zone. The aim is to understand the possible influence of a Kelvin-Helmholtz hydrodynamical instability with mixing zone, compared to classical Kelvin-Helmholtz instability with interface and with theoretical results of Rayleigh-Taylor instability. (A.L.B.)

  8. Understanding semantics

    DEFF Research Database (Denmark)

    Thrane, Torben

    1997-01-01

    Understanding natural language is a cognitive, information-driven process. Discussing some of the consequences of this fact, the paper offers a novel look at the semantic effect of lexical nouns and the identification of reference types....

  9. Understanding Alzheimer's

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Understanding Alzheimer's Past Issues / Fall 2007 Table of Contents For ... and brain scans. No treatment so far stops Alzheimer's. However, for some in the disease's early and ...

  10. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  11. Chlorophyll modulation of mixed layer thermodynamics in a mixed-layer isopycnal General Circulation Model - An example from Arabian Sea and equatorial Pacific

    Digital Repository Service at National Institute of Oceanography (India)

    Nakamoto, S.; PrasannaKumar, S.; Oberhuber, J.M.; Saito, H.; Muneyama, K.; Frouin, R.

    is influenced not only by local vertical mixing but also by horizontal con- vergence of mass and heat, a mixed layer model must consider both full dynamics due to the use of primitive equations and a parameterization for the vertical mass transfer and related... is dynamically determined without such a con- straint. Instantaneous atmospheric elds are inter- polated from the monthly means. Monthly mean climatology of chlorophyll pigment concentrations were obtained from the Coastal Zone Color Scan- ner (CZCS) from...

  12. Understanding homelessness

    OpenAIRE

    Somerville, Peter

    2013-01-01

    This paper reviews the literature on understanding homelessness. It criticizes approaches that ignore, distort or diminish the humanity of homeless people, or else, add little to our understanding of that humanity. In particular, it rejects what it calls “epidemiological” approaches, which deny the possibility of agency for homeless people, insofar as those approaches view the situation of those people largely as a “social fact”, to be explained in terms of causal variables or “risk factors” ...

  13. Diel vertical migration arising in a habitat selection game

    DEFF Research Database (Denmark)

    Sainmont, Julie; Thygesen, Uffe Høgsbro; Visser, Andre

    2013-01-01

    Predator and prey react to each other, adjusting their behavior to maximize their fitness and optimizing their food intake while keeping their predation risk as low as possible. In a pelagic environment, prey reduce their predation mortality by adopting a diel vertical migration (DVM) strategy...... for the predator as well as the prey. We formulated three scenarios in plankton ecology in order to address this question. A novel finding is that mixed strategies emerge as optimal over a range of the parameter space, where part of the predator or prey population adopts a DVM while the rest adopt one or other...

  14. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  15. Plug cementing: Horizontal to vertical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Calvert, D.G.; Heathman, J.F.; Griffith, J.E.

    1995-12-31

    This paper presents an in-depth study of cement plug placement that was conducted with large-scale models for the improvement of plug cementing practices and plug integrity. Common hole and workstring geometries were examined with various rheology and density ratios between the drilling fluid and cement. The critical conditions dictating the difference between success and failure for various wellbore angles and conditions were explored, and the mechanisms controlling slurry movement before and after placement are now better understood. An understanding of these mechanisms allows the engineer to better tailor a design to specific hole conditions. Controversial concepts regarding plug-setting practices have been examined and resolved. The cumulative effects of density, rheology, and hole angle are major factors affecting plug success. While the Boycott effect and an extrusion effect were observed to be predominant in inclined wellbores, a spiraling or {open_quotes}roping{close_quotes} effect controls slurry movement in vertical wellbores. Ultimate success of a cement plug can be obtained if allowances are made for these effects in the job design, provided all other previously published recommended placement practices are followed. Results of this work can be applied to many sidetracking and plug-to-abandon operations. Additionally, the understanding of the fluid movement (creep) mechanisms holds potential for use in primary and remedial cementing work, and in controlling the placement of noncementitious fluids in the wellbore.

  16. Mixed Methods Approaches in Family Science Research

    Science.gov (United States)

    Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

    2008-01-01

    The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

  17. Who Will Use Pre-Exposure Prophylaxis (PrEP) and Why?: Understanding PrEP Awareness and Acceptability amongst Men Who Have Sex with Men in the UK--A Mixed Methods Study.

    Science.gov (United States)

    Frankis, Jamie; Young, Ingrid; Flowers, Paul; McDaid, Lisa

    2016-01-01

    Recent clinical trials suggest that pre-exposure prophylaxis (PrEP) may reduce HIV transmission by up to 86% for men who have sex with men (MSM), whilst relatively high levels of PrEP acceptability have been reported to date. This study examines PrEP awareness amongst sub-groups of MSM communities and acceptability amongst MSM in a low prevalence region (Scotland, UK), using a mixed methods design. Quantitative surveys of n = 690 MSM recruited online via social and sociosexual media were analysed using descriptive statistics and multivariate logistic regression. In addition, n = 10 in-depth qualitative interviews with MSM were analysed thematically. Under one third (29.7%) of MSM had heard of PrEP, with awareness related to living in large cities, degree level education, commercial gay scene use and reporting an HIV test in the last year. Just under half of participants (47.8%) were likely to use PrEP if it were available but there was no relationship between PrEP acceptability and previous PrEP awareness. Younger men (18-25 years) and those who report higher risk UAI were significantly more likely to say they would use PrEP. Qualitative data described specific PrEP scenarios, illustrating how risk, patterns of sexual practice and social relationships could affect motivation for and nature of PrEP use. These findings suggest substantial interest PrEP amongst MSM reporting HIV risk behaviours in Scotland. Given the Proud results, there is a strong case to investigate PrEP implementation within the UK. However, it appears that disparities in awareness have already emerged along traditional indicators of inequality. Our research identifies the need for comprehensive support when PrEP is introduced, including a key online component, to ensure equity of awareness across diverse MSM communities (e.g. by geography, education, gay scene use and HIV proximity), as well as to responding to the diverse informational and sexual health needs of all MSM communities.

  18. Consolidation by Prefabricated Vertical Drains with a Threshold Gradient

    OpenAIRE

    Xiao Guo; Kang-He Xie; Yue-Bao Deng

    2014-01-01

    This paper shows the development of an approximate analytical solution of radial consolidation by prefabricated vertical drains with a threshold gradient. To understand the effect of the threshold gradient on consolidation, a parametric analysis was performed using the present solution. The applicability of the present solution was demonstrated in two cases, wherein the comparisons with Hansbo’s results and observed data were conducted. It was found that (1) the flow with the threshold gradie...

  19. Understanding Maple

    CERN Document Server

    Thompson, Ian

    2016-01-01

    Maple is a powerful symbolic computation system that is widely used in universities around the world. This short introduction gives readers an insight into the rules that control how the system works, and how to understand, fix, and avoid common problems. Topics covered include algebra, calculus, linear algebra, graphics, programming, and procedures. Each chapter contains numerous illustrative examples, using mathematics that does not extend beyond first-year undergraduate material. Maple worksheets containing these examples are available for download from the author's personal website. The book is suitable for new users, but where advanced topics are central to understanding Maple they are tackled head-on. Many concepts which are absent from introductory books and manuals are described in detail. With this book, students, teachers and researchers will gain a solid understanding of Maple and how to use it to solve complex mathematical problems in a simple and efficient way.

  20. Atmospheric mixing ratios of methyl ethyl ketone (2-butanone in tropical, boreal, temperate and marine environments

    Directory of Open Access Journals (Sweden)

    A. M. Yáñez-Serrano

    2016-09-01

    Full Text Available Methyl ethyl ketone (MEK enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs such as n-butane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with proton-transfer-reaction mass spectrometer (PTR-MS instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia. Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere.

  1. Capillary holdup between vertical spheres

    Directory of Open Access Journals (Sweden)

    S. Zeinali Heris

    2009-12-01

    Full Text Available The maximum volume of liquid bridge left between two vertically mounted spherical particles has been theoretically determined and experimentally measured. As the gravitational effect has not been neglected in the theoretical model, the liquid interface profile is nonsymmetrical around the X-axis. Symmetry in the interface profile only occurs when either the particle size ratio or the gravitational force becomes zero. In this paper, some equations are derived as a function of the spheres' sizes, gap width, liquid density, surface tension and body force (gravity/centrifugal to estimate the maximum amount of liquid that can be held between the two solid spheres. Then a comparison is made between the result based on these equations and several experimental results.

  2. Convective evaporation of vertical films.

    Science.gov (United States)

    Boulogne, François; Dollet, Benjamin

    2018-02-28

    Motivated by the evaporation of soap films, which has a significant effect on their lifetime, we performed an experimental study on the evaporation of vertical surfaces with model systems based on hydrogels. From the analogy between heat and mass transfer, we adopt a model describing the natural convection in the gas phase due to a density contrast between dry and saturated air. Our measurements show a good agreement with this model, both in terms of scaling law with the Grashof number and in terms of order of magnitude. We discuss the corrections to take into account, notably the contribution of edge effects, which have a small but visible contribution when lateral and bottom surface areas are not negligible compared to the main evaporating surface area.

  3. Understanding physics

    CERN Document Server

    Mansfield, Michael

    2011-01-01

    Understanding Physics - Second edition is a comprehensive, yet compact, introductory physics textbook aimed at physics undergraduates and also at engineers and other scientists taking a general physics course. Written with today's students in mind, this text covers the core material required by an introductory course in a clear and refreshing way. A second colour is used throughout to enhance learning and understanding. Each topic is introduced from first principles so that the text is suitable for students without a prior background in physics. At the same time the book is designed to enable

  4. Scour at Vertical Piles in Sand-Clay Mixtures under Waves

    DEFF Research Database (Denmark)

    Dey, Subhasish; Helkjær, Anders; Sumer, B. Mutlu

    2011-01-01

    Marine sediments often contain sand-clay mixtures in widely varying proportions. This study presents the results of equilibrium scour and time variation of scour depths at circular piles embedded vertically in clay alone and sand-clay mixed beds under waves. Experiments were conducted in a wave f...

  5. Continuous mixing of solids

    NARCIS (Netherlands)

    Raouf, M.S.

    1963-01-01

    The most important literature on theoretical aspects of mixing solids was reviewed.

    Only when the mixed materials showed no segregation it was possible to analyse the mixing process quantitatively. In this case the mixture could be described by the 'χ' Square test. Longitudinal mixing could be

  6. Surface mixing and biological activity in the four Eastern Boundary Upwelling Systems

    Directory of Open Access Journals (Sweden)

    V. Rossi

    2009-08-01

    Full Text Available Eastern Boundary Upwelling Systems (EBUS are characterized by a high productivity of plankton associated with large commercial fisheries, thus playing key biological and socio-economical roles. Since they are populated by several physical oceanic structures such as filaments and eddies, which interact with the biological processes, it is a major challenge to study this sub- and mesoscale activity in connection with the chlorophyll distribution. The aim of this work is to make a comparative study of these four upwelling systems focussing on their surface stirring, using the Finite Size Lyapunov Exponents (FSLEs, and their biological activity, based on satellite data. First, the spatial distribution of horizontal mixing is analysed from time averages and from probability density functions of FSLEs, which allow us to divide each areas in two different subsystems. Then we studied the temporal variability of surface stirring focussing on the annual and seasonal cycle. We also proposed a ranking of the four EBUS based on the averaged mixing intensity. When investigating the links with chlorophyll concentration, the previous subsystems reveal distinct biological signatures. There is a global negative correlation between surface horizontal mixing and chlorophyll standing stocks over the four areas. To try to better understand this inverse relationship, we consider the vertical dimension by looking at the Ekman-transport and vertical velocities. We suggest the possibility of a changing response of the phytoplankton to sub/mesoscale turbulence, from a negative effect in the very productive coastal areas to a positive one in the open ocean. This study provides new insights for the understanding of the variable biological productivity in the ocean, which results from both dynamics of the marine ecosystem and of the 3-D turbulent medium.

  7. Understanding Energy

    Science.gov (United States)

    Menon, Deepika; Shelby, Blake; Mattingly, Christine

    2016-01-01

    "Energy" is a term often used in everyday language. Even young children associate energy with the food they eat, feeling tired after playing soccer, or when asked to turn the lights off to save light energy. However, they may not have the scientific conceptual understanding of energy at this age. Teaching energy and matter could be…

  8. An Introduction to LANL Mixed Potential Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brosha, Eric Lanich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kreller, Cortney [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-26

    These are slides for a webinar given on the topics of an introduction to LANL mixed potential sensors. Topics include the history of LANL electrochemical sensor work, an introduction to mixed potential sensors, LANL uniqueness, and an application of LANL mixed potential sensors. The summary is as follows: Improved understanding of the mixed-potential sensor mechanism (factors controlling the sensor response identified), sensor design optimized to maximize sensor sensitivity and durability (porous electrolyte/dense electrodes), electrodes selected for various specific applications (CO, HC, H2), sensor operating parameters optimized for improved gas selectivity (NOx, NH3).

  9. [Occlusal vertical dimension in removable complete dentures].

    Science.gov (United States)

    den Haan, R; Witter, D J

    2011-12-01

    In removable complete dentures, the occlusal vertical dimension is an important factor for patients' satisfaction with aesthetics. An excessively reduced occlusal vertical dimension is especially likely to lead to complaints about aesthetics, whereas an increased occlusal vertical dimension may lead to discomfort and a decision not to wear the complete dentures. There are various methods for determining the occlusal vertical dimension in complete dentures, based on the vertical dimension in the rest position of the mandible or on phonetics. However, none of the methods have proven to be clearly superior, in terms of reliability, than the others. The assessment of the occlusal vertical dimension will become more reliable if several methods are used simultaneously. Moreover, knowledge of the characteristics of the ageing face is essential.

  10. Vertical Distribution of Soil Organic Carbon Density in Relation to Land Use/Cover, Altitude and Slope Aspect in the Eastern Himalayas

    Directory of Open Access Journals (Sweden)

    Tshering Dorji

    2014-10-01

    Full Text Available In-depth understanding about the vertical distribution of soil organic carbon (SOC density is crucial for carbon (C accounting, C budgeting and designing appropriate C sequestration strategies. We examined the vertical distribution of SOC density under different land use/land cover (LULC types, altitudinal zones and aspect directions in a montane ecosystem of Bhutan. Sampling sites were located using conditioned Latin hypercube sampling (cLHS scheme. Soils were sampled based on genetic horizons. An equal-area spline function was fitted to interpolate the target values to predetermined depths. Linear mixed model was fitted followed by mean separation tests. The results show some significant effects of LULC, altitudinal zone and slope aspect on the vertical distribution of SOC density in the profiles. Based on the proportion of mean SOC density in the first 20 cm relative to the cumulative mean SOC density in the top meter, the SOC density under agricultural lands (34% was more homogeneously distributed down the profiles than forests (39%, grasslands (59% and shrublands (43%. Similarly, the SOC density under 3500–4000 m zone (35% was more uniformly distributed compared to 3000–3500 m zone (43% and 1769–2500 m and 2500–3000 m zones (41% each. Under different aspect directions, the north and east-facing slopes (38% each had more uniform distribution of SOC density than south (40% and west-facing slopes (49%.

  11. Sodar detection of mixing height in flat and mountainous terrain

    Energy Technology Data Exchange (ETDEWEB)

    Hennemuth, B [Consulting Meteorologist, Hamburg (Germany); Kirtzel, H-Juergen [METEK GmbH, Elmshorn (Germany)], E-mail: barbara.hennemuth@zmaw.de

    2008-05-01

    The atmospheric boundary layer plays an important role in air pollution and dispersion problems because the transport processes are managed within this layer and its top limits the vertical exchange of pollutants. A method for the derivation of the mixing height from measurements of sodar, RASS and sonic anemometer-thermometer is presented for flat terrain. It does not only use vertical profiles of measured parameters but also bulk information like histograms and time evolution. Results from a two-years period are verified by radiosonde-derived mixing height values and show the potential of the combination of the three systems to monitor the mixing height. Difficulties arise at locations in mountainous terrain where thermal wind regimes dominate which are highly non-local. An additional problem is a strong local heat source at an industrial site where even the definition of the mixing height is unclear.

  12. On Vertical Relations and Technology Adoption Timing

    OpenAIRE

    Maria Alipranti; Chrysovalantou Milliou; Emmanuel Petrakis

    2015-01-01

    This paper explores how vertical relations influence the timing of new technology adoption. It shows that both the bargaining power distribution among the vertically related firms and the contract type through which vertical trading is conducted affect crucially the speed of adoption: the downstream firms can adopt later a new technology when the upstream bargaining power increases as well as when wholesale price contracts, instead of two-part tariffs, are employed. Importantly, it shows that...

  13. REVIEW ON METHODS OF RECORDING VERTICAL RELATION

    OpenAIRE

    Naveen Raj; Ashish; Shantanu; Honey

    2013-01-01

    INTRODUCTION: The accuracy of recording vertical dimension at occ lusion in edentulous patients is always a prime consideration for any dent ist. Though there are many advances in techniques and materials employed in the field of pro sthodontics for recording vertical dimension at occlusion; still, there is no accurate method of assessing vertical dimension of occlusion in edentulous patients available to denti st. In assessing this component for fabrication o...

  14. Turbulent vertical diffusivity in the sub-tropical stratosphere

    Directory of Open Access Journals (Sweden)

    I. Pisso

    2008-02-01

    Full Text Available Vertical (cross-isentropic mixing is produced by small-scale turbulent processes which are still poorly understood and paramaterized in numerical models. In this work we provide estimates of local equivalent diffusion in the lower stratosphere by comparing balloon borne high-resolution measurements of chemical tracers with reconstructed mixing ratio from large ensembles of random Lagrangian backward trajectories using European Centre for Medium-range Weather Forecasts analysed winds and a chemistry-transport model (REPROBUS. We focus on a case study in subtropical latitudes using data from HIBISCUS campaign. An upper bound on the vertical diffusivity is found in this case study to be of the order of 0.5 m2 s−1 in the subtropical region, which is larger than the estimates at higher latitudes. The relation between diffusion and dispersion is studied by estimating Lyapunov exponents and studying their variation according to the presence of active dynamical structures.

  15. Horizontal stresses induced by vertical processes in planetary lithospheres

    Science.gov (United States)

    Banerdt, W. B.

    1993-01-01

    Understanding the state of stress in the elastic lithosphere is of fundamental importance for planetary geophysics, as it is the link between the observed geologic structures on the surface and the processes which form and modify these structures. As such, it can provide valuable constraints for the difficult problem of determining interior structure and processes. On the Earth, most large scale, organized deformation can be related to lateral tectonics associated with plate dynamics; however, the tectonics on many extraterrestrial bodies (such as the Moon, Mars, and most of the outer-planet satellites) appears to be primarily vertical in nature, and the horizontal stresses induced by vertical motions and loads are expected to dominate the deformation of their lithospheres. The largest stress contributions from vertical loading come from the flexure of the lithosphere, which induces both bending moments and membrane stresses. We are concerned here only with nonflexural changes in the state of stress induced by processes such as sedimentary and volcanic deposition, erosional denudation, and changes in the thermal gradient that induce uplift or subsidence. This analysis is important both for evaluating stresses for specific regions in which the vertical stress history can be estimated, as well as for applying the proper loading conditions to global stress models. It is also of interest for providing a reference state of stress for interpreting stress measurements in the crust of the Earth.

  16. Advancements of vertically aligned liquid crystal displays.

    Science.gov (United States)

    Kumar, Pankaj; Jaggi, Chinky; Sharma, Vandna; Raina, Kuldeep Kumar

    2016-02-01

    This review describes the recent advancements in the field of the vertical aligned (VA) liquid crystal displays. The process and formation of different vertical alignment modes such as conventional VA, patterned VA, multi-domain VA, and polymer stabilised VA etc are widely discussed. Vertical alignment of liquid crystal due to nano particle dispersion in LC host, bifunctional PR-SAM formed by silane coupling reaction to oxide surfaces, azo dye etc., are also highlighted and discussed. Overall, the article highlights the advances in the research of vertical aligned liquid crystal in terms of their scientific and technological aspects. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Understanding translation

    DEFF Research Database (Denmark)

    Schjoldager, Anne Gram; Gottlieb, Henrik; Klitgård, Ida

    Understanding Translation is designed as a textbook for courses on the theory and practice of translation in general and of particular types of translation - such as interpreting, screen translation and literary translation. The aim of the book is to help you gain an in-depth understanding...... of the phenomenon of translation and to provide you with a conceptual framework for the analysis of various aspects of professional translation. Intended readers are students of translation and languages, but the book will also be relevant for others who are interested in the theory and practice of translation...... - translators, language teachers, translation users and literary, TV and film critics, for instance. Discussions focus on translation between Danish and English....

  18. Understanding Resilience

    Directory of Open Access Journals (Sweden)

    Gang eWu

    2013-02-01

    Full Text Available Resilience is the ability to adapt successfully in the face of stress and adversity. Stressful life events, trauma and chronic adversity can have a substantial impact on brain function and structure, and can result in the development of PTSD, depression and other psychiatric disorders. However, most individuals do not develop such illnesses after experiencing stressful life events, and are thus thought to be resilient. Resilience as successful adaptation relies on effective responses to environmental challenges and ultimate resistance to the deleterious effects of stress, therefore a greater understanding of the factors that promote such effects is of great relevance. This review focuses on recent findings regarding genetic, epigenetic, developmental, psychosocial and neurochemical factors that are considered essential contributors to the development of resilience. Neural circuits and pathways involved in mediating resilience are also discussed. The growing understanding of resilience factors will hopefully lead to the development of new pharmacological and psychological interventions for enhancing resilience and mitigating the untoward consequences.

  19. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  20. Understanding users

    DEFF Research Database (Denmark)

    Johannsen, Carl Gustav Viggo

    2014-01-01

    Segmentation of users can help libraries in the process of understanding user similarities and differences. Segmentation can also form the basis for selecting segments of target users and for developing tailored services for specific target segments. Several approaches and techniques have been...... segmentation project using computer-generated clusters. Compared to traditional marketing texts, this article also tries to identify user segments or images or metaphors by the library profession itself....

  1. Understanding unemployment

    OpenAIRE

    Guillaume Rocheteau

    2006-01-01

    Modern economists have built models of the labor market, which isolate the market’s key drivers and describe the way these interact to produce particular levels of unemployment. One of the most popular models used by macroeconomists today is the search-matching model of equilibrium unemployment. We explain this model, and show how it can be applied to understand the way various policies, such as unemployment benefits, taxes, or technological changes, can affect the unemployment rate.

  2. Understanding Technology?

    Directory of Open Access Journals (Sweden)

    Erik Bendtsen

    2016-11-01

    Full Text Available We are facing radical changes in our ways of living in the nearest future. Not necessarily of our own choice, but because tchnological development is moving so fast, that it will have still greater impact on many aspects of our lives. We have seen the beginnings of that change within the latest 35 years or so, but according to newest research that change will speed up immensely in the nearest years to come. The impact of that change or these changes will affect our working life immensely as a consequence of automation. How these changes are brought about and which are their consequences in a broad sense is being attempted to be understood and guessed by researchers. No one knows for sure, but specific patterns are visible. This paper will not try to guess, what will come, but will rather try to understand the deepest ”nature” of technology in order to understand the driving factors in this development: the genesis of technology in a broad sense in order to contibute to the understanding of the basis for the expected development.

  3. On flavor violation for massive and mixed neutrinos

    International Nuclear Information System (INIS)

    Blasone, M.; Capolupo, A.; Ji, C.R.; Vitiello, G.

    2009-01-01

    We discuss flavor charges and states for interacting mixed neutrinos in QFT. We show that the Pontecorvo states are not eigenstates of the flavor charges. This implies that their use in describing the flavor neutrinos produces a violation of lepton charge conservation in the production/detection vertices. The flavor states defined as eigenstates of the flavor charges give the correct representation of mixed neutrinos in charged current weak interaction processes.

  4. Optimization of VCSELs for Self-Mixing Sensing

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Chung, Il-Sug

    2010-01-01

    We have simulated the variations in optical output power from a vertical-cavity surface-emitting laser (VCSEL) subject to self-mixing feedback, which is very important for applications in sensing. In order to maximize the self-mixing signal for a given feedback we have optimized the epitaxial...... design of the VCSEL. The most important parameters are the number of quantum wells (gain), the number of Bragg mirrors (reflection), and the detector position....

  5. Experiences of ZAMG on mixing height determination

    Energy Technology Data Exchange (ETDEWEB)

    Piringer, M. [Zentralanstalt fuer Meteorologie und Geodynamik, ZAMG, Vienna (Austria)

    1997-10-01

    Temperature inversions in the boundary layer occur quite often, esp. in mountainous terrain by which Austria is covered to a large extent, and can lead to enhanced pollution at the surface because the air volume available for dilution is then vertically limited. The Department of Environmental Meteorology of ZAMG therefore set up several field programs in the past to study such conditions at a variety of sites in Austria, using tethersondes and Sodars. Early investigations aimed at comparing Sodar echo profiles to the tethersonde temperature profiles to derive mixing heights from the Sodar echo structure. More recently, evolving from KONGEX, the `convective boundary layer experiment`, mixing heights calculated for Vienna by the OML model were compared to those derived from radiosonde and tethersonde potential temperature profiles. Results of these investigations will be presented, focussing on the problems when using the different methods. New efforts to derive mixing heights from data were also undertaken and are discussed separately. (au)

  6. Mixing of solids in different mixing devices

    Indian Academy of Sciences (India)

    The results obtained by those three devices, the particle size effect and cohesion indexes, bring us to the conclusion that static mixers could be used for mixing of powders, but their shape, number of mixing elements and the mixer length should be adapted for each mixture separately, experimentally and mathematically, ...

  7. Different stages and status of vertical transporting process of Cu in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Li, Haixia; Wang, Qi; Zhang, Xiaolong; Ding, Jun

    2017-12-01

    Understanding the stages and status of vertical transporting process of pollutant in marine bay is essential to pollution control. This paper analyzed the stages and status of Cu’s vertical transporting process in waters in Jiaozhou Bay. Results showed that the vertical transporting process in waters in Jiaozhou Bay included four stages of 1) Cu was imported to the bay by major sources, 2) Cu was transported to surface waters, 3) Cu was transported from surface waters to sediment in sea bottom, and 4) Cu was fixed and buried in sediment. Furthermore, Cu’s vertical transporting process could be divided into seven status in detail, and he characteristics of the vertical transport process of Cu were also analyzed.

  8. Vertical and horizontal access configurations

    International Nuclear Information System (INIS)

    Spampinato, P.T.

    1987-01-01

    A number of configuration features and maintenance operations are influenced by the choice of whether a design is based on vertical or horizontal access for replacing reactor components. The features which are impacted most include the first wall/blanket segmentation, the poloidal field coil locations, the toroidal field coil number and size, access port size for in-vessel components, and facilities. Since either configuration can be made to work, the choice between the two is not clear cut because both have certain advantages. It is apparent that there are large cost benefits in the poloidal field coil system for ideal coil locations for high elongation plasmas and marginal savings for the INTOR case. If we assume that a new tokamak design will require a higher plasma elongation, the recommendation is to arrange the poloidal field coils in a cost-effective manner while providing reasonable midplane access for heating interfaces and test modules. If a new design study is not based on a high elongation plasma, it still appears prudent to consider this approach so that in-vessel maintenance can be accomplished without moving very massive structures such as the bulk shield. 10 refs., 29 figs., 3 tabs

  9. Understanding uncertainty

    CERN Document Server

    Lindley, Dennis V

    2013-01-01

    Praise for the First Edition ""...a reference for everyone who is interested in knowing and handling uncertainty.""-Journal of Applied Statistics The critically acclaimed First Edition of Understanding Uncertainty provided a study of uncertainty addressed to scholars in all fields, showing that uncertainty could be measured by probability, and that probability obeyed three basic rules that enabled uncertainty to be handled sensibly in everyday life. These ideas were extended to embrace the scientific method and to show how decisions, containing an uncertain element, could be rationally made.

  10. Metodología combinada para entender la duración del amamantamiento en barrios pobres de Managua, Nicaragua A mixed-method approach to understanding breast-feeding duration in urban low-income neighborhoods in Managua, Nicaragua

    Directory of Open Access Journals (Sweden)

    Janet Irene Picado

    1997-12-01

    to the duration of exclusive breast-feeding and the total duration of breast-feeding, along with attitudes, perceptions, and beliefs about breast-feeding among women living in poor neighborhoods of Managua, Nicaragua. The field work was carried out in December 1992 and January 1993 using qualitative and quantitative methods. A structured questionnaire was administered in interviews with 556 mothers of children under 12 months of age, and meetings of four directed discussion groups were held, in which a total of 20 women participated. At one week of age, almost all the children of the mothers who were surveyed had been breast-fed, but only 45% had been exclusively breast-fed. At 12 weeks old, 30% were already completely weaned. The discussion groups revealed the coexistence of positive opinions about both breast-feeding and bottle-feeding. However, exclusive breast-feeding was considered harmful for the mother, and breast milk was not thought to be sufficient nourishment for the child. Previous experience was strongly related to the duration of exclusive breast-feeding and to total breast-feeding duration. Attitudes, social support, and work situation were important factors influencing the total length of time women breast-fed a child. In general, the results obtained through the interviews and in the discussion groups were in agreement and showed that the elements needed to promote exclusive breast-feeding were social support, a favorable community environment, and policies that dealt with problems faced by working mothers. The complementary research methods were useful for obtaining information about the relative importance of different factors that determine the duration of breast-feeding and for understanding that practice in greater depth from the mother's point of view.

  11. Understanding analysis

    CERN Document Server

    Abbott, Stephen

    2015-01-01

    This lively introductory text exposes the student to the rewards of a rigorous study of functions of a real variable. In each chapter, informal discussions of questions that give analysis its inherent fascination are followed by precise, but not overly formal, developments of the techniques needed to make sense of them. By focusing on the unifying themes of approximation and the resolution of paradoxes that arise in the transition from the finite to the infinite, the text turns what could be a daunting cascade of definitions and theorems into a coherent and engaging progression of ideas. Acutely aware of the need for rigor, the student is much better prepared to understand what constitutes a proper mathematical proof and how to write one. Fifteen years of classroom experience with the first edition of Understanding Analysis have solidified and refined the central narrative of the second edition. Roughly 150 new exercises join a selection of the best exercises from the first edition, and three more project-sty...

  12. Understanding ayurveda.

    Science.gov (United States)

    Gadgil, Vaidya Dilip

    2010-01-01

    Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda's power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  13. Understanding Ayurveda

    Directory of Open Access Journals (Sweden)

    Vaidya Dilip Gadgil

    2010-01-01

    Full Text Available Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda′s power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  14. Safety Aspects for Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.; Christiani, E.

    1996-01-01

    In this appendix some safety aspects in relation to vertical wall breakwaters are discussed. Breakwater structures such as vertical wall breakwaters are used under quite different conditions. The expected lifetime can be from 5 years (interim structure) to 100 years (permanent structure) and the ...

  15. The green building envelope : Vertical greening

    NARCIS (Netherlands)

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve

  16. Vertical Files in Midlands Academic Libraries.

    Science.gov (United States)

    Lillis, John G.

    1991-01-01

    Reviews survey responses from 127 nonmedical academic libraries in Nebraska, Iowa, and Kansas regarding their vertical files (e.g., acquisitions, weeding, size, nature, collection management, frequency of use, maintenance of statistics, types of users, circulation, and security), reporting that 109 had vertical files, with most emphasizing topics…

  17. Lidar measured vertical atmospheric scattering profiles

    NARCIS (Netherlands)

    Kunz, G.J.

    1985-01-01

    The vertical structure of the atmosphere, which is of invaluable interest to meteorologists, geo-physicists and environmental researchers, can be measured with LIDAR. A method has been proposed and applied to invert lidar signals from vertical soundings to height resolved scattering coefficients. In

  18. Plasmon Modes of Vertically Aligned Superlattices

    DEFF Research Database (Denmark)

    Filonenko, Konstantin; Duggen, Lars; Willatzen, Morten

    2017-01-01

    By using the Finite Element Method we visualize the modes of vertically aligned superlattice composed of gold and dielectric nanocylinders and investigate the emitter-plasmon interaction in approximation of weak coupling. We find that truncated vertically aligned superlattice can function as plas...

  19. Teaching Students the Verticality of Technical Documentation.

    Science.gov (United States)

    Hager, Peter J.

    1992-01-01

    Advocates making technical writing courses more vertical in structure by including an extensive study of at least one specific form of technical documentation. Examines how students can gain experience in the vertical process by designing, writing, testing, and producing user manuals for on-campus cooperative education clients. Lists the benefits…

  20. Variability of the Mixed-Layer Height Over Mexico City

    Science.gov (United States)

    García-Franco, J. L.; Stremme, W.; Bezanilla, A.; Ruiz-Angulo, A.; Grutter, M.

    2018-02-01

    The diurnal and seasonal variability of the mixed-layer height in urban areas has implications for ground-level air pollution and the meteorological conditions. Measurements of the backscatter of light pulses with a commercial lidar system were performed for a continuous period of almost six years between 2011 and 2016 in the southern part of Mexico City. The profiles were temporally and vertically smoothed, clouds were filtered out, and the mixed-layer height was determined with an ad hoc treatment of both the filtered and unfiltered profiles. The results are in agreement when compared with values of mixed-layer height reconstructed from, (i) radiosonde data, and (ii) surface and vertical column densities of a trace gas. The daily maxima of the mean mixed-layer height reach values > 3 km above ground level in the months of March-April, and are clearly lower (pollution episodes and the height of the mixed layer. The growth rate of the convective mixed-layer height has a seasonal behaviour, which is characterized together with the mixed-layer-height anomalies. A clear residual layer is evident from the backscattered signals recorded in days with specific atmospheric conditions, but also from the cloud-filtered mean diurnal profiles. The occasional presence of a residual layer results in an overestimation of the reported mixed-layer height during the night and early morning hours.

  1. Vertically-integrated Approaches for Carbon Sequestration Modeling

    Science.gov (United States)

    Bandilla, K.; Celia, M. A.; Guo, B.

    2015-12-01

    Carbon capture and sequestration (CCS) is being considered as an approach to mitigate anthropogenic CO2 emissions from large stationary sources such as coal fired power plants and natural gas processing plants. Computer modeling is an essential tool for site design and operational planning as it allows prediction of the pressure response as well as the migration of both CO2 and brine in the subsurface. Many processes, such as buoyancy, hysteresis, geomechanics and geochemistry, can have important impacts on the system. While all of the processes can be taken into account simultaneously, the resulting models are computationally very expensive and require large numbers of parameters which are often uncertain or unknown. In many cases of practical interest, the computational and data requirements can be reduced by choosing a smaller domain and/or by neglecting or simplifying certain processes. This leads to a series of models with different complexity, ranging from coupled multi-physics, multi-phase three-dimensional models to semi-analytical single-phase models. Under certain conditions the three-dimensional equations can be integrated in the vertical direction, leading to a suite of two-dimensional multi-phase models, termed vertically-integrated models. These models are either solved numerically or simplified further (e.g., assumption of vertical equilibrium) to allow analytical or semi-analytical solutions. This presentation focuses on how different vertically-integrated models have been applied to the simulation of CO2 and brine migration during CCS projects. Several example sites, such as the Illinois Basin and the Wabamun Lake region of the Alberta Basin, are discussed to show how vertically-integrated models can be used to gain understanding of CCS operations.

  2. Numerical study of evaporation in a vertical annulus heated at the inner wall

    Energy Technology Data Exchange (ETDEWEB)

    Ben Radhia, R.; Ben Jabrallah, S. [Laboratoire d' Energetique et des Transferts Thermique et Massique, Faculte des Sciences de Tunis, 1060 Tunis, Universite Tunis El Manar (Tunisia); Ben Jabrallah, S. [Faculte des sciences de Bizerte, 7021 Bizerte, Universite du 7 Novembre a Carthage (Tunisia); Corriou, J.P. [LRGP, Nancy Universite, CNRS-ENSIC-INPL, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France); Harmand, S. [Universite de Lille Nord de France, F-59000 Lille UVHC/TEMPO, F-59313 Valenciennes Cedex (France)

    2011-10-15

    Mixed convection during evaporation of a water falling film in a vertical concentric annulus was studied numerically. The water thin film falls on the inner tube and is subjected to a constant heat flux density, whereas the outer cylinder is assumed to be insulated and dry. An imposed air flow circulates within the gap between the two concentric tubes. The objective of this work is to understand the evaporation phenomenon in order to improve the average evaporated mass flux density and heat and mass transfer. Conservative equations governing the gas phase are solved numerically using the finite volume method. In the liquid phase, a method based on local heat and mass balances on each level is used. Thus, the following liquid film parameters, feed water mass flow, feed temperature and heat flux density, are taken into account. The obtained results are analyzed to emphasize and evaluate the influence of the previous operating parameters and the annulus curvature on the effective evaporation surface and on the mass flux density of evaporated water. (authors)

  3. Numerical study of evaporation in a vertical annulus heated at the inner wall

    International Nuclear Information System (INIS)

    Ben Radhia, R.; Ben Jabrallah, S.; Ben Jabrallah, S.; Corriou, J.P.; Harmand, S.

    2011-01-01

    Mixed convection during evaporation of a water falling film in a vertical concentric annulus was studied numerically. The water thin film falls on the inner tube and is subjected to a constant heat flux density, whereas the outer cylinder is assumed to be insulated and dry. An imposed air flow circulates within the gap between the two concentric tubes. The objective of this work is to understand the evaporation phenomenon in order to improve the average evaporated mass flux density and heat and mass transfer. Conservative equations governing the gas phase are solved numerically using the finite volume method. In the liquid phase, a method based on local heat and mass balances on each level is used. Thus, the following liquid film parameters, feed water mass flow, feed temperature and heat flux density, are taken into account. The obtained results are analyzed to emphasize and evaluate the influence of the previous operating parameters and the annulus curvature on the effective evaporation surface and on the mass flux density of evaporated water. (authors)

  4. Physics of vertically integrated waveguide photodetectors and amplifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wright, E.M. [Univ. of Arizona, Tucson, AZ (United States). Optical Sciences Center

    1993-11-01

    This report describes the efforts supported by LLNL under the Subcontract No. B239593 at the University of Arizona during the Fiscal Year 1992. A solid physical foundation has been developed for understanding the operation of vertically integrated photodetectors and amplifiers. This has been achieved through a combination of numerical simulation and development of simple coupled-mode theories. Coupled-mode theory has been used to elucidate the physics underlying the operation of vertically integrated photodetectors. In particular, the relation between the spatial transients observed in experiments and numerical simulations, and the non-power orthogonality of the underlying modes has been clarified. The coupled-mode theory has been extended to the case of coupled waveguide-amplifiers.

  5. Understanding physics

    CERN Document Server

    Cassidy, David; Rutherford, James

    2002-01-01

    Understanding Physics provides a thorough grounding in contemporary physics while placing physics into its social and historical context Based in large part on the highly respected Project Physics Course developed by two of the authors, it also integrates the results of recent pedagogical research The text thus - teaches about the basic phenomena in the physical world and the concepts developed to explain them - shows that science is a rational human endeavor with a long and continuing tradition, involving many different cultures and people - develops facility in critical thinking, reasoned argumentation, evaluation of evidence, mathematical modeling, and ethical values The treatment emphasizes not only what we know but also how we know it, why we believe it, and what effects that knowledge has - Why do we believe the Earth and planets revolve around the Sun? - Why do we believe that matter is made of atoms? - How do relativity theory and quantum mechanics alter our conception of Nature and in what ways do th...

  6. Eat and run? The hunger/satiation hypothesis in vertical migration: history, evidence and consequences.

    Science.gov (United States)

    Pearre, Sifford

    2003-02-01

    The study of vertical migrations in aquatic organisms has a long and colourful history, much of it to do with the effects of changing sampling technology on our understanding of the phenomenon. However, the overwhelming majority of such studies carried out today still depend on detecting differences in vertical distribution profiles during some course of time, or acoustic echoes of migrating bands of organisms. These can not distinguish migratory activity of individual organisms, but can only assess net results of mass transfers of populations, which may integrate many individual migrations. This is an important distinction, for without knowing the actual movements of individuals it seems unlikely that we will be able to understand their causes, nor the effects of vertical migrations on the environment or on the migrators themselves. This review examines evidence for individual vertical movements gathered from 'tracers', mainly gut contents, and reviews the evidence for the hypothesis that such movements are in fact driven by hunger and satiation. The more recently appreciated vertical migrations of phytoplankters and their similarities in form and driving forces to those of zooplankton and nekton are also discussed. Finally, the role of vertical migrators in vertical fluxes of materials is discussed, along with the consequences of satiation-driven descent for such estimates.

  7. Seasonal variability of the mixed layer in the central Bay of Bengal and associated changes in nutrients and chlorophyll

    Digital Repository Service at National Institute of Oceanography (India)

    Narvekar, J.; PrasannaKumar, S.

    greater wind-driven mixing, while the intrusion of high-salinity waters erodes the halocline and weakens the upper-layer stratification of the water column and aids in vertical mixing. The deep MLD in the south during winter was driven by wind-mixing when...

  8. SPORT MARKETING MIX STRATEGIES

    OpenAIRE

    Alexandru Lucian MIHAI

    2013-01-01

    This paper presents a brief overview of a significant element of the sport marketing management model called the marketing mix. The marketing mix is crucial because it defines the sport business, and much of the sport marketer’s time is spent on various functions within the marketing mix. The marketing mix is the strategic combination of the product, price, place and promotion elements. These elements are typically called the four Ps of marketing. Decisions and strategies for each are importa...

  9. Estimates of gradient Richardson numbers from vertically smoothed data in the Gulf Stream region

    Directory of Open Access Journals (Sweden)

    Paul van Gastel

    2004-12-01

    Full Text Available We use several hydrographic and velocity sections crossing the Gulf Stream to examine how the gradient Richardson number, Ri, is modified due to both vertical smoothing of the hydrographic and/or velocity fields and the assumption of parallel or geostrophic flow. Vertical smoothing of the original (25 m interval velocity field leads to a substantial increase in the Ri mean value, of the same order as the smoothing factor, while its standard deviation remains approximately constant. This contrasts with very minor changes in the distribution of the Ri values due to vertical smoothing of the density field over similar lengths. Mean geostrophic Ri values remain always above the actual unsmoothed Ri values, commonly one to two orders of magnitude larger, but the standard deviation is typically a factor of five larger in geostrophic than in actual Ri values. At high vertical wavenumbers (length scales below 3 m the geostrophic shear only leads to near critical conditions in already rather mixed regions. At these scales, hence, the major contributor to shear mixing is likely to come from the interaction of the background flow with internal waves. At low vertical wavenumbers (scales above 25 m the ageostrophic motions provide the main source for shear, with cross-stream movements having a minor but non-negligible contribution. These large-scale motions may be associated with local accelerations taking place during frontogenetic phases of meanders.

  10. A Vertical Diffusion Scheme to estimate the atmospheric rectifier effect

    Science.gov (United States)

    Chen, Baozhang; Chen, Jing M.; Liu, Jane; Chan, Douglas; Higuchi, Kaz; Shashkov, Alexander

    2004-02-01

    The magnitude and spatial distribution of the carbon sink in the extratropical Northern Hemisphere remain uncertain in spite of much progress made in recent decades. Vertical CO2 diffusion in the planetary boundary layer (PBL) is an integral part of atmospheric CO2 transport and is important in understanding the global CO2 distribution pattern, in particular, the rectifier effect on the distribution [Keeling et al., 1989; Denning et al., 1995]. Attempts to constrain carbon fluxes using surface measurements and inversion models are limited by large uncertainties in this effect governed by different processes. In this study, we developed a Vertical Diffusion Scheme (VDS) to investigate the vertical CO2 transport in the PBL and to evaluate CO2 vertical rectification. The VDS was driven by the net ecosystem carbon flux and the surface sensible heat flux, simulated using the Boreal Ecosystem Productivity Simulator (BEPS) and a land surface scheme. The VDS model was validated against half-hourly CO2 concentration measurements at 20 m and 40 m heights above a boreal forest, at Fraserdale (49°52'29.9''N, 81°34'12.3''W), Ontario, Canada. The amplitude and phase of the diurnal/seasonal cycles of simulated CO2 concentration during the growing season agreed closely with the measurements (linear correlation coefficient (R) equals 0.81). Simulated vertical and temporal distribution patterns of CO2 concentration were comparable to those measured at the North Carolina tower. The rectifier effect, in terms of an annual-mean vertical gradient of CO2 concentration in the atmosphere that decreases from the surface to the top of PBL, was found at Fraserdale to be about 3.56 ppmv. Positive covariance between the seasonal cycles of plant growth and PBL vertical diffusion was responsible for about 75% of the effect, and the rest was caused by covariance between their diurnal cycles. The rectifier effect exhibited strong seasonal variations, and the contribution from the diurnal cycle

  11. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  12. Conditions for super-adiabatic droplet growth after entrainment mixing

    Directory of Open Access Journals (Sweden)

    F. Yang

    2016-07-01

    Full Text Available Cloud droplet response to entrainment and mixing between a cloud and its environment is considered, accounting for subsequent droplet growth during adiabatic ascent following a mixing event. The vertical profile for liquid water mixing ratio after a mixing event is derived analytically, allowing the reduction to be predicted from the mixing fraction and from the temperature and humidity for both the cloud and environment. It is derived for the limit of homogeneous mixing. The expression leads to a critical height above the mixing level: at the critical height the cloud droplet radius is the same for both mixed and unmixed parcels, and the critical height is independent of the updraft velocity and mixing fraction. Cloud droplets in a mixed parcel are larger than in an unmixed parcel above the critical height, which we refer to as the “super-adiabatic” growth region. Analytical results are confirmed with a bin microphysics cloud model. Using the model, we explore the effects of updraft velocity, aerosol source in the environmental air, and polydisperse cloud droplets. Results show that the mixed parcel is more likely to reach the super-adiabatic growth region when the environmental air is humid and clean. It is also confirmed that the analytical predictions are matched by the volume-mean cloud droplet radius for polydisperse size distributions. The findings have implications for the origin of large cloud droplets that may contribute to onset of collision–coalescence in warm clouds.

  13. Mixing height determination from the momentum balance of the neutral or stable PBL

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, J.C. [Risoe National Lab., Roskilde (Denmark)

    1997-10-01

    The mixing height is defined by the top of the layer of turbulent mixing. This height is equal to the height H of turbulent vertical momentum transport (fiction) in neutral or stable stratification. In very stable cases, the wave induced momentum transport must be excluded if the waves do not have mixing effects (e.g. break) within the frictional layer. Thus the conditions provided by the momentum balance determine the mixing height in most cases of mechanical turbulence. Mixing is a time dependent process and depends also on the height of release of substance to be mixed. It depends on the specific form of the exchange coefficient function whether the mixing time for the mixed layer is finite of infinite. If this time is infinite, an additional mixing time criterion for a substance released close to the ground must be applied for the determination of the corresponding mixing height. (au)

  14. Vertical velocities at an ocean front

    Directory of Open Access Journals (Sweden)

    Pedro Vélez-Belchí

    2001-07-01

    Full Text Available Simple scaling arguments conclude that the dominant motions in the ocean are horizontal. However, the vertical velocity plays a crucial role, connecting the active upper layer with the deep ocean. Vertical velocities are mostly associated with the existence of non-transient atmospheric wind forcing or with the presence of mesoscale features. The former are the well known upwelling areas, usually found at the eastern side of the oceans and characterised by upward vertical velocities. The latter have been observed more recently in a number of areas of the world´s oceans, where the vertical velocity has been found to be of the order of several tens of meters per day, that is, an order of magnitude higher than the largest vertical velocity usually observed in upwelling areas. Nevertheless, at present, vertical velocities cannot be measured and indirect methods are therefore needed to estimate them. In this paper, the vertical velocity field is inferred via the quasi-geostrophic omega equation, using density data from a quasi-permanent upper ocean front located at the northern part of the western Alborán gyre.

  15. Mixing vane grid spacer

    International Nuclear Information System (INIS)

    Patterson, J.F.; Galbraith, K.P.

    1978-01-01

    An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability is described. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints

  16. Measurements of the vertical profile of water vapor abundance in the Martian atmosphere from Mars Observer

    Science.gov (United States)

    Schofield, J. T.; Mccleese, Daniel J.

    1988-01-01

    An analysis is presented of the Pressure Modulator Infrared Radiometer (PMIRR) capabilities along with how the vertical profiles of water vapor will be obtained. The PMIRR will employ filter and pressure modulation radiometry using nine spectral channels, in both limb scanning and nadir sounding modes, to obtain daily, global maps of temperature, dust extinction, condensate extinction, and water vapor mixing ratio profiles as a function of pressure to half scale height or 5 km vertical resolution. Surface thermal properties will also be mapped, and the polar radiactive balance will be monitored.

  17. Localised mixing and heterogeneity in the plankton food web in a frontal region of the Sargasso Sea:implications for eel early life history?

    OpenAIRE

    Richardson, Katherine; Bendtsen, Jørgen; Christensen, Jens Tang; Adjou, Mohamed; Lyngsgaard, Maren Moltke; Hilligsøe, Karen Marie; Pedersen, Jens Brøgger; Vang, Torben; Nielsen, Morten Holtegaard

    2014-01-01

    Previous studies have demonstrated that patches of eel larvae are found in the frontal region of the Subtropical Convergence Zone (STCZ), but to date no clear evidence of why this region might confer advantage to the larvae has been presented. This study demonstrates that there may be localized patches within a frontal region in the STCZ in the Sargasso Sea that experience elevated vertical mixing and an associated vertical flux of nutrients. This localized vertical mixing was suggested by a ...

  18. Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sednev, Igor; Sednev, I.; Menon, S.; McFarquhar, G.

    2008-02-18

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9th-10th October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase

  19. Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiationmechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sednev, I.; Menon, S.; McFarquhar, G.

    2009-04-10

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during October 9th-10th, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-hour simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase

  20. Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms

    Directory of Open Access Journals (Sweden)

    G. McFarquhar

    2009-07-01

    Full Text Available The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9–10 October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors' concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process

  1. Wind driven vertical transport in a vegetated, wetland water column with air-water gas exchange

    Science.gov (United States)

    Poindexter, C.; Variano, E. A.

    2010-12-01

    gas transfer coefficient, k, for both a vegetated condition and a control condition (no cylinders). The presence of cylinders in the tank substantially increased the rate of the gas transfer. For the highest wind speed, the gas transfer coefficient was several times higher when cylinders were present compared to when they were not. The gas transfer coefficient for the vegetated condition also proved sensitive to wind speed, increasing markedly with increasing mean wind speeds. Profiles of dissolved oxygen revealed well-mixed conditions in the bulk water column following prolonged air-flow above the water surface, suggesting application of the thin-film model is appropriate. The enhanced gas exchange observed might be explained by increased turbulent kinetic energy within the water column and the anisotropy of the cylinder array, which constrains horizontal motions more than vertical motions. Improved understanding of gas exchange in vegetated water columns may be of particularly use to investigations of carbon fluxes and soil accretion in wetlands. Reference: Nepf, H. (1999), Drag, turbulence, and diffusion in flow through emergent vegetation, Water Resour. Res., 35(2), 479-489.

  2. CBCT in diagnosis of vertical root fracture

    Directory of Open Access Journals (Sweden)

    Mohan Thomas Nainan

    2012-01-01

    Full Text Available The clinical presentation and radiographic appearance of a vertical root fracture frequently pose a diagnostic dilemma to the clinician. Lack of definitive diagnosis often leads to unnecessary invasive surgery and/or extraction of the tooth. Often exploratory surgery is resorted in order to visualize the fracture. Conventional two-dimensional radiography, including periapical and bitewing radiograph and currently cone-beam computerized tomography (CBCT are being used to detect vertical root fractures. This article reviews the role of CBCT in detecting vertical root fractures.

  3. Understanding PISA

    Directory of Open Access Journals (Sweden)

    Stephen DOWNES

    2005-04-01

    Full Text Available Understanding PISA Stephen DOWNESMoncton, CANADA ABSTRACT The headline was dramatic enough to cause a ripple in the reading public. "Students who use computers a lot at school have worse maths and reading performance," noted the BBC news article, citing a 2004 study by Ludger Woessmann and Thomas Fuchs (Fuchs and Woessman, 2004. It was not long before the blogosphere took notice. Taking the theme and running with it, Alice and Bill ask, "Computers Make School Kids Dumber?" They theorize, "If you track the admitted decline of education, you'll probably notice that it follows along with the increase of technology in the classroom." In a similar vein, James Bartholomew asks, "Do you think that the government will turn down the volume of its boasting about how it has spent billions introducing computers in schools (while keeping down the pay of teachers so much that there are shortages? Do you think it will stop sending governors of state schools glossy pamphlets about insisting that computers are used in their schools as much as possible?" In this study, therefore, PISA looks well beyond educational attainment, and also includes school demographics, such as whether it is a public or private school, has large or small classes, or has access or not to technological resources. Finally, it does measure student information-their family background, access to books and computers and parental support as well. The PISA survey departs from previous surveys in disregarding the stated curricula of the schools being measured. Therefore, the conclusion is not surprising, nor even wrong for him to consider independently of any parental or teacher support, considered without reference to the software running on it, considered without reference to student attitudes and interests, does not positively impact an education. Finally, he focus on missing the reporting of results

  4. The Mystery of Neutrino Mixings

    CERN Document Server

    Altarelli, Guido

    2011-01-01

    In the last years we have learnt a lot about neutrino masses and mixings. Neutrinos are not all massless but their masses are very small. Probably masses are small because neutrinos are Majorana particles with masses inversely proportional to the large scale M of lepton number (L) violation, which turns out to be compatible with the GUT scale. We have understood that there is no contradiction between large neutrino mixings and small quark mixings, even in the context of GUTs and that neutrino masses fit well in the SUSY GUT picture. Out of equilibrium decays with CP and L violation of heavy RH neutrinos can produce a B-L asymmetry, then converted near the weak scale by instantons into an amount of B asymmetry compatible with observations (baryogenesis via leptogenesis). It appears that active neutrinos are not a significant component of Dark Matter in the Universe. A long list of models have been formulated over the years to understand neutrino masses and mixings. With the continuous improvement of the data m...

  5. Advances in compressible turbulent mixing

    Energy Technology Data Exchange (ETDEWEB)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  6. Mixing in Long Cylinder by a Stratified Jet: Laboratory Modeling and Theory

    Science.gov (United States)

    Nath, C.; Voropayev, S. I.; Fernando, H. J. S.

    2011-11-01

    The evolution of buoyant turbulent jets released into a low aspect ratio (width/height) cavity filled with a homogeneous fluid was investigated experimentally. The motivation was to understand mixing process in U.S. Strategic Petroleum Reserves (SPR), where crude oil is stored in salt caverns of aspect ratio approximately 0.1. During maintenance, degassed oil is introduced as a jet from the top of the caverns while denser gas-laden crude oil is pumped out from the bottom. The focus was on mixing, formation and development of density layer as well as the time for replenishing oil in the container to an acceptable level of vapor pressure (gas concentration). Basing on the results of experiments a theoretical model was advanced which permits to calculate the vertical density distributions in cavern as a function of time and other external parameters. Satisfactory agreement between theory and measurements was demonstrated. The results obtained could be extrapolated to SPR flow mixing situations and help to improve the efficiency of expensive oil cavern refilling. This research is supported by the Sandia National Laboratories.

  7. Stratification and Tdal Mixing in the Cretaceous Western Interior Seaway

    Science.gov (United States)

    Allison, P. A.; Hill, J.; Jordan, N.; Avdis, A.; Markwick, P. J.; Lunt, D. J.

    2013-12-01

    Most of the organic carbon preserved in the marine sedimentary lithosphere was deposited in shallow epicontinental seas. Understanding the processes which affected productivity and preservation of this organic matter impacts upon our understanding of the ancient carbon cycle, paleobiodiversity and hydrocarbon resource formation. The epicontinental seas of the geological past were vast, typically shallow and lack suitably scaled modern analogues. A key question is the extent to which these water-bodies were stratified or mixed and how this has affected productivity and preservation. Modern coastal seas such as the North Sea become seasonally stratified in summer but are mixed at the coasts through the interaction of the tidal wave with the seabed. The stratified deeper water is separated from the mixed coastal shallows by a front. Modern fronts are associated with elevated productivity in the frontal region with potential for preservation in stratified areas. Herein we use a range of modelling tools to evaluate the development of seasonal stratification, tidal mixing and tidal fronts in the Cretaceous Western Interior Seaway (WIS) of North America. The paleogeographies (supplied by Getech) used for this work are underpinned by extensive geological databases and based on an in-house plate model. Paleobathymetric reconstructions utilize geological observations (seismic, lithofacies, fossils) for the shelf and a combination of geological data and age-depth relationships for areas underpinned by oceanic crust. A low resolution coupled atmosphere-ocean general circulation model (HADCM3) was used to evaluate the development of seasonal stratification. Fluidity-ICOM, an unstructured FE model was used to quantify the development of tidal mixing and tidal fronts and GOTM, a 1D vertical ocean model was used to evaluate the impact of a suite of parameters (salinity, temperature, depth and atmospheric forcing) on water-body mixing. HADCM3 results show that the seaway was

  8. Turbulent mixing induced by Richtmyer-Meshkov instability

    Science.gov (United States)

    Krivets, V. V.; Ferguson, K. J.; Jacobs, J. W.

    2017-01-01

    Richtmyer-Meshkov instability is studied in shock tube experiments with an Atwood number of 0.7. The interface is formed in a vertical shock tube using opposed gas flows, and three-dimensional random initial interface perturbations are generated by the vertical oscillation of gas column producing Faraday waves. Planar Laser Mie scattering is used for flow visualization and for measurements of the mixing process. Experimental image sequences are recorded at 6 kHz frequency and processed to obtain the time dependent variation of the integral mixing layer width. Measurements of the mixing layer width are compared with Mikaelian's [1] model in order to extract the growth exponent θ where a fairly wide range of values is found varying from θ ≈ 0.2 to 0.6.

  9. Structure of binary mixed polymer Langmuir layers

    OpenAIRE

    Bernardini, C.

    2012-01-01

    The possibility of preparing 2D stable emulsions through mixing of homopolymers in a Langmuir monolayer is the core topic of this thesis. While colloid science has achieved well established results in the study of bulk dispersed systems, accounts on properties of mixed monomolecular films are fewer, and seldom systematic. The aim of this investigation is to contribute to a deeper understanding of the subject, in order to explore opportunities to apply the acquired knowledge to the fabrication...

  10. Relationships between Vertical Profiles of Radar Observed Vertical Velocity and Reflectivity in Convective Storms

    Science.gov (United States)

    Barnes, H.; Hagos, S. M.; Feng, Z.; Williams, C. R.; Protat, A.

    2017-12-01

    Complex relationships exist between vertical motions and microphysical processes. One source of data that provides insight into microphysical processes within convection is radar reflectivity. This study provides insight into the dynamical-microphysical interactions by evaluating several theoretical explanations that describe the relationship between vertical profiles of vertical velocity and radar reflectivity. These theoretical explanations are evaluated using data from convective storms observed near Darwin, Australia. This study first evaluates whether the vertical profile of vertical velocity can be used to describe characteristics of the vertical radar reflectivity profile. Then, the reverse is considered and this study investigates whether the vertical profile of radar reflectivity can be used to provide insight into the vertical profile of vertical velocity. These theoretical explanations are important since they provide a means to compare simulated and observed dynamical-microphysical interactions and aid in the development of future cumulus and microphysical parameterizations. Additionally, they may increase our ability observe the statistical characteristics of vertical velocity, which is highly desired by the modeling community.

  11. A high speed vertical axis wind machine

    National Research Council Canada - National Science Library

    South, P

    1976-01-01

    The operational feasibility of vertical axis wind machines was investigated at the National Aeronautical Establishment in Ottawa through use of a wind tunnel and a rotor with blades curved in a skipping rope shape...

  12. Prefabricated vertical drains, vol. I : engineering guidelines.

    Science.gov (United States)

    1986-09-01

    This volume presents procedures and guidelines applicable to the design and instal : tion of prefabricated vertical drains to accelerate consolidation of soils. The : contents represent the Consultant's interpretation of the state-of-the-art as of : ...

  13. Relevance ranking for vertical search engines

    CERN Document Server

    Chang, Yi

    2014-01-01

    In plain, uncomplicated language, and using detailed examples to explain the key concepts, models, and algorithms in vertical search ranking, Relevance Ranking for Vertical Search Engines teaches readers how to manipulate ranking algorithms to achieve better results in real-world applications. This reference book for professionals covers concepts and theories from the fundamental to the advanced, such as relevance, query intention, location-based relevance ranking, and cross-property ranking. It covers the most recent developments in vertical search ranking applications, such as freshness-based relevance theory for new search applications, location-based relevance theory for local search applications, and cross-property ranking theory for applications involving multiple verticals. It introduces ranking algorithms and teaches readers how to manipulate ranking algorithms for the best results. It covers concepts and theories from the fundamental to the advanced. It discusses the state of the art: development of ...

  14. HL-LHC vertical cryostat during construction

    CERN Multimedia

    Lanaro, Andrea

    2016-01-01

    7m high "Cluster D" vertical test cryostat during construction at contractor's premises, Alca Technology Srl, in Schio, Italy. The inner helium vessel with its heat exchanger are visible. To be installed in the D pit in SMA18.

  15. Vertical profiles of droplet effective radius in shallow convective clouds

    Directory of Open Access Journals (Sweden)

    S. Zhang

    2011-05-01

    >fad becomes smaller, representing a higher degree of mixing, and re becomes smaller (~10 % and more variable. However, for the clean case, smaller fad corresponds to larger re (and larger re variability, reflecting the additional influence of droplet collision-coalescence and sedimentation on re. Finally, profiles of the vertically inhomogeneous clouds as simulated by the LES and those of the vertically homogeneous clouds are used as input to a radiative transfer model to study the effect of cloud vertical inhomogeneity on shortwave radiative forcing. For clouds that have the same liquid water path, re of a vertically homogeneous cloud must be about 76–90 % of the cloud-top re of the vertically inhomogeneous cloud in order for the two clouds to have the same shortwave radiative forcing.

  16. Growing Vertical in the Flatland.

    Science.gov (United States)

    Robinson, Joshua A

    2016-01-26

    The world of two-dimensional (2D) heterostructures continues to expand at a rate much greater than anyone could have predicted 10 years ago, but if we are to make the leap from science to technology, many materials challenges must still be overcome. Recent advances, such as those by Liu et al. in this issue of ACS Nano, demonstrate that it is possible to grow rotationally commensurate 2D heterostructures, which could pave the way toward single crystal van der Waals solids. In this Perspective, I provide some insight into a few of the challenges associated with growth of heterostructures, and discuss some of the recent works that help us better understand synthetic realization of 2D heterostructures.

  17. Updated Vertical Extent of Collision Damage

    DEFF Research Database (Denmark)

    Tagg, R.; Bartzis, P.; Papanikolaou, P.

    2002-01-01

    The probabilistic distribution of the vertical extent of collision damage is an important and somewhat controversial component of the proposed IMO harmonized damage stability regulations for cargo and passenger ships. The only pre-existing vertical distribution, currently used in the international...... cargo ship regulations, was based on a very simplified presumption of bow heights. This paper investigates the development of this damage extent distribution based on three independent methodologies; actual casualty measurements, world fleet bow height statistics, and collision simulation modeling...

  18. Reliability Analysis of Existing Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Sørensen, John Dalsgaard

    1998-01-01

    Vertical wall breakwaters are used under quite different conditions where failure of the breakwater or a part of it will have very different consequences. Further a number of existing vertical wall breakwaters have been subjected to significant wave loads which have caused partial failures of the...... of the structures. The main objective of this paper is to describe how the reliability of existing breakwater structures within the expected remaining lifetime can be estimated taking into account the available information....

  19. Vertical Scan-Conversion for Filling Purposes

    OpenAIRE

    Hersch, R. D.

    1988-01-01

    Conventional scan-conversion algorithms were developed independently of filling algorithms. They cause many problems, when used for filling purposes. However, today's raster printers and plotters require extended use of filling, especially for the generation of typographic characters and graphic line art. A new scan-conversion algorithm, called vertical scan-conversion has been specifically designed to meet the requirements of parity scan line fill algorithms. Vertical scan-conversion ensures...

  20. MIXED AND MIXING SYSTEMS WORLDWIDE: A PREFACE

    Directory of Open Access Journals (Sweden)

    Seán Patrick Donlan

    2012-09-01

    Full Text Available This issue of the Potchefstroom Electronic Law Journal (South Africa sees thepublication of a selection of articles derived from the Third International Congress ofthe World Society of Mixed Jurisdiction Jurists (WSMJJ. That Congress was held atthe Hebrew University of Jerusalem, Israel in the summer of 2011. It reflected athriving Society consolidating its core scholarship on classical mixed jurisdictions(Israel, Louisiana, the Philippines, Puerto Rico, Quebec, Scotland, and South Africawhile reaching to new horizons (including Cyprus, Hong Kong and Macau, Malta,Nepal, etc. This publication reflects in microcosm the complexity of contemporaryscholarship on mixed and plural legal systems. This complexity is, of course, wellunderstoodby South African jurists whose system is derived both from the dominantEuropean traditions as well as from African customary systems, including both thosethat make up part of the official law of the state as well as those non-state norms thatcontinue to be important in the daily lives of many South Africans.

  1. Horizontal stress in planetary lithospheres from vertical processes

    Science.gov (United States)

    Banerdt, W. B.

    1991-01-01

    Understanding the stress states in a lithosphere is of fundamental importance for planetary geophysics. It is closely linked to the processes which form and modify tectonic features on the surface and reflects the behavior of the planet's interior, providing a constraint for the difficult problem of determining interior structure and processes. The tectonics on many extraterrestrial bodies (Moon, Mars, and most of the outer planet satellites) appears to be mostly vertical, and the horizontal stresses induced by vertical motions and loads are expected to dominate the deformation of their lithospheres. Herein, only changes are examined in the state of stress induced by processes such as sedimentary and volcanic deposition, erosional denudation, and changes in the thermal gradient that induce uplift or subsidence. This analysis is important both for evaluating stresses for specific regions in which the vertical stress history can be estimated, as well as for applying the proper loading conditions to global stress models. All references to lithosphere herein should be understood to refer to the elastic lithosphere, that layer which deforms elastically or brittlely when subjected to geologically scaled stresses.

  2. The origin and vertical distribution of carbon monoxide in Jupiter

    Science.gov (United States)

    Noll, Keith S.; Knacke, R. F.; Geballe, T. R.; Tokunaga, A. T.

    1988-01-01

    Six clearly-resolved lines of the CO 1-0 vibration-rotation band near 4.7 microns have been observed in Jupiter at a resolution of 0.07/cm. CO is not found to be concentrated in the stratosphere, but is shown to be present in the troposphere at a mole fraction of 1.6 + or - 0.3 x 10 to the -9th, suggesting that rapid vertical mixing is the source of CO. Results indicate that the global oxygen abundance in Jupiter's gaseous envelope below the cloud-forming regions must be near the solar value, and that intervening clouds with an optical depth of 0.5-4 are present above the line-forming region.

  3. Vertical bipolar charge plasma transistor with buried metal layer.

    Science.gov (United States)

    Nadda, Kanika; Kumar, M Jagadesh

    2015-01-19

    A self-aligned vertical Bipolar Charge Plasma Transistor (V-BCPT) with a buried metal layer between undoped silicon and buried oxide of the silicon-on-insulator substrate, is reported in this paper. Using two-dimensional device simulation, the electrical performance of the proposed device is evaluated in detail. Our simulation results demonstrate that the V-BCPT not only has very high current gain but also exhibits high BVCEO · f(T) product making it highly suitable for mixed signal high speed circuits. The proposed device structure is also suitable for realizing doping-less bipolar charge plasma transistor using compound semiconductors such as GaAs, SiC with low thermal budgets. The device is also immune to non-ideal current crowding effects cropping up at high current densities.

  4. European mixed forests

    DEFF Research Database (Denmark)

    Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian

    2014-01-01

    Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material...... and Methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any...... developmental stage, sharing common resources (light, water, and/or soil nutrients). The presence of each of the component species is normally quantified as a proportion of the number of stems or of basal area, although volume, biomass or canopy cover as well as proportions by occupied stand area may be used...

  5. MARKETING MIX THEORETICAL ASPECTS

    OpenAIRE

    Margarita Išoraitė

    2016-01-01

    Aim of article is to analyze marketing mix theoretical aspects. The article discusses that marketing mix is one of the main objectives of the marketing mix elements for setting objectives and marketing budget measures. The importance of each element depends not only on the company and its activities, but also on the competition and time. All marketing elements are interrelated and should be seen in the whole of their actions. Some items may have greater importance than others; it depends main...

  6. Mixed waste management options

    International Nuclear Information System (INIS)

    Owens, C.B.; Kirner, N.P.

    1992-01-01

    Currently, limited storage and treatment capacity exists for commercial mixed waste streams. No commercial mixed waste disposal is available, and it has been estimated that if and when commercial mixed waste disposal becomes available, the costs will be high. If high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and management options. Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition) no migration petition) and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly. Another option for mixed waste management that is being explored is the feasibility of Department of Energy (DOE) accepting commercial mixed waste for treatment, storage, and disposal. A study has been completed that analyzes DOE treatment capacity in comparison with commercial mixed waste streams. (author)

  7. Biodegradation at Dynamic Plume Fringes: Mixing Versus Reaction Control

    Science.gov (United States)

    Cirpka, O. A.; Eckert, D.; Griebler, C.; Haberer, C.; Kürzinger, P.; Bauer, R.; Mellage, A.

    2014-12-01

    Biodegradation of continuously emitted plumes is known to be most pronounced at the plume fringe, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. Under steady-state conditions, physical mixing of contaminant and electron acceptor by transverse dispersion was shown to be the major bottleneck for biodegradation, with plume lengths scaling inversely with the bulk transverse dispersivity in quasi two-dimensional settings. Under these conditions, the presence of suitable microbes is essential but the biokinetic parameters do not play an important role. When the location of the plume shifts (caused, e.g., by a fluctuating groundwater table), however, the bacteria are no more situated at the plume fringe and biomass growth, decay, activation and deactivation determine the time lag until the fringe-controlled steady state is approached again. During this time lag, degradation is incomplete. The objective of the presented study was to analyze to which extent flow and transport dynamics diminish effectiveness of fringe-controlled biodegradation and which microbial processes and related biokinetic parameters determine the system response in overall degradation to hydraulic fluctuations. We performed experiments in quasi-two-dimensional flow through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth and maintenance (often subsumed as "biomass decay") microbial dormancy (that is, change into a metabolically inactive state) and

  8. Efficiency of Metal Mixing in Dwarf Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Yutaka [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Saitoh, Takayuki R., E-mail: yutaka.hirai@nao.ac.jp [Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2017-04-01

    Metal mixing plays a critical role in the enrichment of metals in galaxies. The abundance of elements such as Mg, Fe, and Ba in metal-poor stars helps us understand the metal mixing in galaxies. However, the efficiency of metal mixing in galaxies is not yet understood. Here we report a series of N -body/smoothed particle hydrodynamics simulations of dwarf galaxies with different efficiencies of metal mixing using a turbulence-induced mixing model. We show that metal mixing apparently occurs in dwarf galaxies from Mg and Ba abundances. We find that a scaling factor for metal diffusion larger than 0.01 is necessary to reproduce the measured abundances of Ba in dwarf galaxies. This value is consistent with the value expected from turbulence theory and experiments. We also find that the timescale of metal mixing is less than 40 Myr. This timescale is shorter than the typical dynamical times of dwarf galaxies. We demonstrate that the determination of a degree of scatters of Ba abundance by the observation will help us to better constrain the efficiency of metal mixing.

  9. Mixing of solids in different mixing devices

    Indian Academy of Sciences (India)

    Many producers mix several batches before they start the packaging of the material. During storage of different batches, the powders have a tendency to segregate. A static mixer added to storage devices outlet would lead to the final products quality. The ratio of the components in the mixture is most important, since it is, ...

  10. Study of the Process of Hydraulic Mixing in Anaerobic Digester of Biogas Plant

    Directory of Open Access Journals (Sweden)

    Karaeva Julia V.

    2015-03-01

    Full Text Available Two systems of hydraulic mixing in a vertical cylindrical anaerobic digester: standard and modernised are discussed in the paper. Numerical investigations that were carried out are focused on a study of hydrodynamic processes in an aerobic digester using two various systems of hydraulic mixing as well as on analysis of the efficiency of methane fermentation process accomplished under different geometric parameters of an anaerobic digester and systems of hydraulic mixing.

  11. Analysis of the flow structure and heat transfer in a vertical mantle heat exchanger

    DEFF Research Database (Denmark)

    Knudsen, Søren; Morrison, GL; Behnia, M

    2005-01-01

    Velocimetry (PIV) system. A Computational Fluid Dynamics (CFD) model of the vertical mantle heat exchanger was also developed for a detailed evaluation of the heat flux at the mantle wall and at the tank wall. The flow structure was evaluated for both high and low temperature incoming flows and for both......The flow structure inside the inner tank and inside the mantle of a vertical mantle heat exchanger was investigated using a full-scale tank designed to facilitate flow visualisation. The flow structure and velocities in the inner tank and in the mantle were measured using a Particle Image...... initially mixed and initially stratified inner tank and mantle. The analysis of the heat transfer showed that the flow in the mantle near the inlet is mixed convection flow and that the heat transfer is dependent on the mantle inlet temperature relative to the core tank temperature at the mantle level. (C...

  12. Vertical air mass exchange driven by the local circulation on the northern slope of Mount Everest

    Science.gov (United States)

    Zhou, Libo; Zou, Han; Ma, Shupo; Li, Peng; Zhu, Jinhuan; Huo, Cuiping

    2011-01-01

    To better understand vertical air mass exchange driven by local circulation in the Himalayas, the volume flux of air mass is estimated in the Rongbuk Valley on the northern slope of Mount Everest, based on a volume closure method and wind-profiler measurements during the HEST2006 campaign in June 2006. Vertical air mass exchange was found to be dominated by a strong downward mass transfer from the late morning to late night. The average vertical air volume flux was 0.09 m s-1, which could be equivalent to a daily ventilation of 30 times the enclosed valley volume. This vertical air mass exchange process was greatly affected by the evolution of the South Asian summer monsoon (SASM), with a strong downward transfer during the SASM break stage, and a weak transfer during the SASM active stage.

  13. Modal Parameter Identification of New Design of Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.

    2013-01-01

    Vertical axis wind turbines have lower power efficiency than the horizontal axis wind turbines. However vertical axis wind turbines are proven to be economical and noise free on smaller scale. A new design of three bladed vertical axis wind turbine by using two airfoils in construction of each...... blade has been proposed to improve power efficiency. The purpose of two airfoils in blade design of vertical axis wind turbine is to create high lift which in turns gives higher power output. In such case the structural parameter identification is important to understand the system behavior due to its...... Abaqus cae software. The study is limited to evaluate lowest fundamental modal frequencies and mode shapes of proposed wind turbine....

  14. Biomechanical Parameters in Children with Unilateral and Bilateral Clubfoot during Vertical Jumps

    Directory of Open Access Journals (Sweden)

    Renato José Soares

    Full Text Available Abstract Gait analysis may offer information to choose the best exercise-based clinical intervention for the children with clubfoot. However, other motor abilities are not commonly investigated. The aim of this research was to analyze the biomechanics of countermovement vertical jumping in clubfooted children who had undergone surgery. Fourteen children with idiopathic clubfoot were selected and the control group consisted of 11 children. Clubfooted children showed less dorsiflexion in the jump preparation phase. In the impulse phase, this group showed more knee flexion and less plantarflexion associated with less magnitude of vertical reaction force and less muscular activity in the gastrocnemius medialis. In the landing phase, for clubfoot group, we found high loading rate for the first peak of vertical force, less plantarflexion and more knee flexion. Understanding the biomechanical changes of vertical jump landing should assist in better targeting of physical and sporting activities of this population.

  15. Martian Mixed Layer during Pathfinder Mission

    Science.gov (United States)

    Martinez, G. M.; Valero, F.; Vazquez, L.

    2008-09-01

    In situ measurements of the Martian Planetary Boundary Layer (MPBL) encompass only the sur- face layer. Therefore, in order to fully address the MPBL, it becomes necessary to simulate somehow the behaviour of the martian mixed layer. The small-scale processes that happen in the MPBL cause GCM's ([1], [2]) to describe only partially the turbulent statistics, height, convective scales, etc, of the surface layer and the mixed layer. For this reason, 2D and 3D martian mesoscale models ([4], [5]), and large eddy simulations ([4], [6], [7], [8]) have been designed in the last years. Although they are expected to simulate more accurately the MPBL, they take an extremely expensive compu- tational time. Alternatively, we have derived the main turbu- lent characteristics of the martian mixed layer by using surface layer and mixed layer similarity ([9], [10]). From in situ temperature and wind speed measurements, together with quality-tested simu- lated ground temperature [11], we have character- ized the martian mixed layer during the convective hours of Pathfinder mission Sol 25. Mean mixed layer turbulent statistics like tem- perature variance , horizontal wind speed variance , vertical wind speed variance , viscous dissipation rate , and turbu- lent kinetic energy have been calculated, as well as the mixed layer height zi, and the convective scales of wind w? and temperature θ?. Our values, obtained with negligible time cost, match quite well with some previously obtained results via LES's ([4] and [8]). A comparisson between the above obtained mar- tian values and the typical Earth values are shown in Table 1. Convective velocity scale w doubles its counterpart terrestrial typical value, as it does the mean wind speed variances and . On the other hand, the temperature scale θ? and the mean temperature variance are virtually around one order higher on Mars. The limitations of these results concern the va- lidity of the convective mixed layer similarity. This theory

  16. Soft tissue mixed tumor

    Directory of Open Access Journals (Sweden)

    Eiichi Hiraishi

    2009-12-01

    Full Text Available Mixed tumors are relatively common in the skin and salivary glands, but extremely rare in soft tissues, often resulting in diagnostic problems. The occurrence of these tumors in the hand is especially limited. In this article we report the clinical, radiological, and histological features of a mixed tumor of the hypothenar region of the right hand.

  17. The Mixed language Debate

    DEFF Research Database (Denmark)

    A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin.......A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin....

  18. Mixed connective tissue disease.

    Science.gov (United States)

    Gunnarsson, Ragnar; Hetlevik, Siri Opsahl; Lilleby, Vibke; Molberg, Øyvind

    2016-02-01

    The concept of mixed connective tissue disease (MCTD) as a separate connective tissue disease (CTD) has persisted for more than four decades. High titers of antibodies targeting the U1 small nuclear ribonucleoprotein particle (U1 snRNP) in peripheral blood are a sine qua non for the diagnosis of MCTD, in addition to distinct clinical features including Raynaud's phenomenon (RP), "puffy hands," arthritis, myositis, pleuritis, pericarditis, interstitial lung disease (ILD), and pulmonary hypertension (PH). Recently, population-based epidemiology data from Norway estimated the point prevalence of adult-onset MCTD to be 3.8 per 100,000 and the mean annual incidence to be 2.1 per million per year, supporting the notion that MCTD is the least common CTD. Little is known about the etiology of MCTD, but recent genetic studies have confirmed that MCTD is a strongly HLA (​human leukocyte antigen)-linked disease, as the HLA profiles of MCTD differ distinctly from the corresponding profiles of ethnically matched healthy controls and other CTDs. In the first section of this review, we provide an update on the clinical, immunological, and genetic features of MCTD and discuss the relationship between MCTD and the other CTDs. Then we proceed to discuss the recent advances in therapy and our current understanding of prognosis and prognostic factors, especially those that are associated with the more serious pulmonary and cardiovascular complications of the disease. In the final section, we discuss some of the key, unresolved questions related to anti-RNP-associated diseases and indicate how these questions may be approached in future studies. Copyright © 2016. Published by Elsevier Ltd.

  19. Heterogeneous distribution of plankton within the mixed layer and its implications for bloom formation in tropical seas

    DEFF Research Database (Denmark)

    Calbet, Albert; Agersted, Mette Dalgaard; Kaartvedt, Stein

    2015-01-01

    Intensive sampling at the coastal waters of the central Red Sea during a period of thermal stratification, prior to the main seasonal bloom during winter, showed that vertical patches of prokaryotes and microplankton developed and persisted for several days within the apparently density uniform...... of the upper layer. These findings suggest that vertical structures within the mixed layer provide critical seeding stocks that can rapidly exploit nutrient influx during mixing, leading to winter bloom formation...

  20. Vertical integration in the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Mommsen, J.T.

    1977-01-01

    Vertical integration in the nuclear fuel cycle and its contribution to market power of integrated fuel suppliers were studied. The industry subdivision analyzed is the uranium raw materials sector. The hypotheses demonstrated are that (1) this sector of the industry is trending toward vertical integration between production of uranium raw materials and the manufacture of nuclear fuel elements, and (2) this vertical integration confers upon integrated firms a significant market advantage over non-integrated fuel manufacturers. Under microeconomic concepts the rationale for vertical integration is the pursuit of efficiency, and it is beneficial because it increases physical output and decreases price. The Market Advantage Model developed is an arithmetical statement of the relative market power (in terms of price) between non-integrated nuclear fuel manufacturers and integrated raw material/fuel suppliers, based on the concept of the ''squeeze.'' In operation, the model compares net profit and return on sales of nuclear fuel elements between the competitors, under different price and cost circumstances. The model shows that, if integrated and non-integrated competitors sell their final product at identical prices, the non-integrated manufacturer returns a net profit only 17% of the integrated firm. Also, the integrated supplier can price his product 35% below the non-integrated producer's price and still return the same net profit. Vertical integration confers a definite market advantage to the integrated supplier, and the basic source of that advantage is the cost-price differential of the raw material, uranium

  1. Dynamic cyclovergence during vertical translation in humans.

    Science.gov (United States)

    Olasagasti, Itsaso; Bockisch, Christopher J; Zee, David S; Straumann, Dominik

    2011-07-06

    When humans are accelerated along the body vertical, the right and left eyes show oppositely directed torsional modulation (cyclovergence). The origin of this paradoxical response is unknown. We studied cyclovergence during linear sinusoidal vertical motion in healthy humans. A small head-fixed visual target minimized horizontal and vertical motion of the eyes and therefore isolated the torsional component. For stimuli between 1 and 2 Hz (near the natural range of head motion), the phase of cyclovergence with respect to inertial acceleration was 8.7 ± 2.4° (mean ± 95% CI) and the sensitivity (in degrees per second per g) showed a small but statistically significant increase with frequency. These characteristics contrast with those of cycloversion (conjugate torsion) during horizontal (interaural) inertial stimuli at similar frequencies. From these and previous results, we propose that cyclovergence during vertical translation has two sources, one, like cycloversion, from the low-frequency component of linear acceleration, and another, which we term dynamic cyclovergence, with high-pass characteristics. Furthermore, we suggest that this cyclovergence response in humans is a vestige of the response of lateral-eyed animals to vertical linear acceleration of the head.

  2. Microfluidic Mixing: A Review

    Directory of Open Access Journals (Sweden)

    Lung-Ming Fu

    2011-05-01

    Full Text Available The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either “active”, where an external energy force is applied to perturb the sample species, or “passive”, where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers.

  3. Measuring mixing efficiency in experiments of strongly stratified turbulence

    Science.gov (United States)

    Augier, P.; Campagne, A.; Valran, T.; Calpe Linares, M.; Mohanan, A. V.; Micard, D.; Viboud, S.; Segalini, A.; Mordant, N.; Sommeria, J.; Lindborg, E.

    2017-12-01

    Oceanic and atmospheric models need better parameterization of the mixing efficiency. Therefore, we need to measure this quantity for flows representative of geophysical flows, both in terms of types of flows (with vortices and/or waves) and of dynamical regimes. In order to reach sufficiently large Reynolds number for strongly stratified flows, experiments for which salt is used to produce the stratification have to be carried out in a large rotating platform of at least 10-meter diameter.We present new experiments done in summer 2017 to study experimentally strongly stratified turbulence and mixing efficiency in the Coriolis platform. The flow is forced by a slow periodic movement of an array of large vertical or horizontal cylinders. The velocity field is measured by 3D-2C scanned horizontal particles image velocimetry (PIV) and 2D vertical PIV. Six density-temperature probes are used to measure vertical and horizontal profiles and signals at fixed positions.We will show how we rely heavily on open-science methods for this study. Our new results on the mixing efficiency will be presented and discussed in terms of mixing parameterization.

  4. Mixing efficiency in lock release gravity currents

    Science.gov (United States)

    Caulfield, C. P.; Patterson, M. D.

    2005-11-01

    We consider numerically and experimentally mixing in Boussinesq lock release gravity currents. We show quantitatively that mixing is strongly dependent on the lower boundary condition. As the fluid in the current slumps and flows under gravity, Kelvin-Helmholtz billows grow at the current head, entrain ambient fluid as they are swept backwards, and then fall down over the current tail, interacting strongly with a thin layer of dense fluid which remains at the lower boundary. For flows with free-slip lower boundaries, the billows remain largely two- dimensional. Conversely, for flows with no-slip lower boundaries, the current front develops lobes and clefts as ambient fluid is engulfed horizontally and overrun vertically, thus leading inevitably both to convection, and also to strong three-dimensionality. Using the APE framework of Winters et al. (1995), we quantify the time-dependent mixing associated with the engulfed fluid, the overrun fluid, and the billows as they develop streamwise secondary instabilities which trigger turbulence. We also compare the cumulative mixing efficiency with laboratory experiments.

  5. GRAVITATIONAL INSTABILITY OF ROTATING, PRESSURE-CONFINED, POLYTROPIC GAS DISKS WITH VERTICAL STRATIFICATION

    International Nuclear Information System (INIS)

    Kim, Jeong-Gyu; Kim, Woong-Tae; Seo, Young Min; Hong, Seung Soo

    2012-01-01

    We investigate the gravitational instability (GI) of rotating, vertically stratified, pressure-confined, polytropic gas disks using a linear stability analysis as well as analytic approximations. The disks are initially in vertical hydrostatic equilibrium and bounded by a constant external pressure. We find that the GI of a pressure-confined disk is in general a mixed mode of the conventional Jeans and distortional instabilities, and is thus an unstable version of acoustic-surface-gravity waves. The Jeans mode dominates in weakly confined disks or disks with rigid boundaries. On the other hand, when the disk has free boundaries and is strongly pressure confined, the mixed GI is dominated by the distortional mode that is surface-gravity waves driven unstable under their own gravity and thus incompressible. We demonstrate that the Jeans mode is gravity-modified acoustic waves rather than inertial waves and that inertial waves are almost unaffected by self-gravity. We derive an analytic expression for the effective sound speed c eff of acoustic-surface-gravity waves. We also find expressions for the gravity reduction factors relative to a razor-thin counterpart that are appropriate for the Jeans and distortional modes. The usual razor-thin dispersion relation, after correcting for c eff and the reduction factors, closely matches the numerical results obtained by solving a full set of linearized equations. The effective sound speed generalizes the Toomre stability parameter of the Jeans mode to allow for the mixed GI of vertically stratified, pressure-confined disks.

  6. Mixing-controlled uncertainty in long-term predictions of acid rock drainage from heterogeneous waste-rock piles

    Science.gov (United States)

    Pedretti, D.; Beckie, R. D.; Mayer, K. U.

    2015-12-01

    The chemistry of drainage from waste-rock piles at mine sites is difficult to predict because of a number of uncertainties including heterogeneous reactive mineral content, distribution of minerals, weathering rates and physical flow properties. In this presentation, we examine the effects of mixing on drainage chemistry over timescales of 100s of years. We use a 1-D streamtube conceptualization of flow in waste rocks and multicomponent reactive transport modeling. We simplify the reactive system to consist of acid-producing sulfide minerals and acid-neutralizing carbonate minerals and secondary sulfate and iron oxide minerals. We create multiple realizations of waste-rock piles with distinct distributions of reactive minerals along each flow path and examine the uncertainty of drainage geochemistry through time. The limited mixing of streamtubes that is characteristic of the vertical unsaturated flow in many waste-rock piles, allows individual flowpaths to sustain acid or neutral conditions to the base of the pile, where the streamtubes mix. Consequently, mixing and the acidity/alkalinity balance of the streamtube waters, and not the overall acid- and base-producing mineral contents, control the instantaneous discharge chemistry. Our results show that the limited mixing implied by preferential flow and the heterogeneous distribution of mineral contents lead to large uncertainty in drainage chemistry over short and medium time scales. However, over longer timescales when one of either the acid-producing or neutralizing primary phases is depleted, the drainage chemistry becomes less controlled by mixing and in turn less uncertain. A correct understanding of the temporal variability of uncertainty is key to make informed long-term decisions in mining settings regarding the management of waste material.

  7. Measurement of vertical stroke Vcb vertical stroke at the Z energy from B mesons exclusive decays

    International Nuclear Information System (INIS)

    Marinelli, N.

    1998-01-01

    Recent ALEPH, DELPHI and OPAL measurements of the form factors in the exclusive decay modes anti B 0 → D *+ l - anti ν l and anti B 0 →D + l - anti ν l are reviewed here. The values obtained allow an almost model-independent determination of vertical stroke V cb vertical stroke in the HQET framework. (orig.)

  8. Measurement of vertical stroke Vub vertical stroke using b hadron semileptonic decay

    International Nuclear Information System (INIS)

    Abbiendi, G.; Aakesson, P.F.

    2001-01-01

    The magnitude of the CKM matrix element vertical stroke V ub vertical stroke is determined by measuring the inclusive charmless semileptonic branching fraction of beauty hadrons at OPAL based on b → X u lν event topology and kinematics. This analysis uses OPAL data collected between 1991 and 1995, which correspond to about four million hadronic Z decays. We measure Br(b → X u lν) to be (1.63 ±0.53 +0.55 -0.62 ) x 10 -3 . The first uncertainty is the statistical error and the second is the systematic error. From this analysis, vertical stroke V ub vertical stroke is determined to be: vertical stroke V ub vertical stroke =(4.00±0.65(stat) +0.67 -0.76 (sys)±0.19(HQE)) x 10 -3 . The last error represents the theoretical uncertainties related to the extraction of vertical stroke V ub vertical stroke from Br(b→X u l ν) using the Heavy Quark Expansion. (orig.)

  9. Dissociated vertical deviation and eye torsion: Relation to disparity-induced vertical vergence.

    Science.gov (United States)

    Van Rijn, L J; Simonsz, H J; Tusscher, M P

    1997-01-01

    We studied the relation between vertical eye movements and binocular torsion in five subjects with dissociated vertical deviation (DVD). During trials, subject viewed a well illuminated Snellen letter chart, with both eyes uncovered during 4 seconds, Subsequently, DVD was induced by covering one eye during 4 seconds. Finally, both eyes were uncovered during 4 seconds. Several trials were recorded for each subject and covered eye. Eye movements were measured with scleral coils. We found that in all subjects, the vertical divergence followed an exponential course with a time constant of 0.67 ± 0.14 seconds on average. In three of the five subjects this vertical divergence was associated with binocular torsion (cycloversion), partly, in the form of a cycloversional nystagmus. The time course of the vertical divergence as well as the direction and nystagmic nature of the cycloversion was similar to the behaviour that was previously observed in disparity induced vertical vergence in normal subjects. In two of the subjects, the torsion that was associated with the vertical divergence was monocular. Our results indicate that DVD and disparity induced vertical vergence share the same characteristics. In addition, they demonstrate that extorsion associated with the elevation in DVD possibly but not necessarily points at a dissociated torsional deviation.

  10. Dissociated vertical deviation and eye torsion: Relation to disparity-induced vertical vergence

    NARCIS (Netherlands)

    L.J. van Rijn; H.J. Simonsz (Huib); M.P.M. ten Tusscher

    1997-01-01

    textabstractWe studied the relation between vertical eye movements and binocular torsion in five subjects with dissociated vertical deviation (DVD). During trials, subject viewed a well illuminated Snellen letter chart, with both eyes uncovered during 4 seconds. Subsequently, DVD was induced by

  11. A global vertical reference frame based on four regional vertical datums

    Czech Academy of Sciences Publication Activity Database

    Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.

    2004-01-01

    Roč. 48, č. 3 (2004), s. 493-502 ISSN 0039-3169 Institutional research plan: CEZ:AV0Z1003909 Keywords : geopotentinal * local vertical datums * global vertical reference frame Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.447, year: 2004

  12. Liquid storage tanks under vertical excitation

    International Nuclear Information System (INIS)

    Philippacopoulos, A.J.

    1985-01-01

    Until recently, the hydrodynamic effects on liquid storage tanks induced by an earthquake excitation were basically treated for the horizontal component of the earthquake. Recent studies, however, showed that the hydrodynamic effects due to the vertical component of an earthquake may be significant. In these studies the tank is assumed to be fixed at the bottom. This paper is concerned with the hydrodynamic behavior of liquid storage tanks induced by vertical earthquake input excitation. First, the fluid-tank system is treated as a fixed-base system and a simple formula is obtained for the coupled fluid-structure natural frequency. Second, additional interaction effects due to the foundation flexibility on the fluid-tank system are investigated. It is concluded that the foundation flexibility may have a significant effect on the hydrodynamic behavior of the liquid storage tanks under a vertical ground shaking

  13. Vertical vibration analysis for elevator compensating sheave

    International Nuclear Information System (INIS)

    Watanabe, Seiji; Nakazawa, Daisuke; Fukui, Daiki; Okawa, Takeya

    2013-01-01

    Most elevators applied to tall buildings include compensating ropes to satisfy the balanced rope tension between the car and the counter weight. The compensating ropes receive tension by the compensating sheave, which is installed at the bottom space of the elevator shaft. The compensating sheave is only suspended by the compensating ropes, therefore, the sheave can move vertically while the car is traveling. This paper shows the elevator dynamic model to evaluate the vertical motion of the compensating sheave. Especially, behavior in emergency cases, such as brake activation and buffer strike, was investigated to evaluate the maximum upward motion of the sheave. The simulation results were validated by experiments and the most influenced factor for the sheave vertical motion was clarified

  14. Vertical vibration analysis for elevator compensating sheave

    Science.gov (United States)

    Watanabe, Seiji; Okawa, Takeya; Nakazawa, Daisuke; Fukui, Daiki

    2013-07-01

    Most elevators applied to tall buildings include compensating ropes to satisfy the balanced rope tension between the car and the counter weight. The compensating ropes receive tension by the compensating sheave, which is installed at the bottom space of the elevator shaft. The compensating sheave is only suspended by the compensating ropes, therefore, the sheave can move vertically while the car is traveling. This paper shows the elevator dynamic model to evaluate the vertical motion of the compensating sheave. Especially, behavior in emergency cases, such as brake activation and buffer strike, was investigated to evaluate the maximum upward motion of the sheave. The simulation results were validated by experiments and the most influenced factor for the sheave vertical motion was clarified.

  15. Plasmonic Properties of Vertically Aligned Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    Hua Qi

    2012-01-01

    Full Text Available Nanowires (NWs/Ag sheath composites were produced to investigate plasmonic coupling between vertically aligned NWs for surface-enhanced Raman scattering (SERS applications. In this investigation, two types of vertical NW arrays were studied; those of ZnO NWs grown on nanosphere lithography patterned sapphire substrate via vapor-liquid-solid (VLS mechanism and Si NW arrays produced by wet chemical etching. Both types of vertical NW arrays were coated with a thin layer of silver by electroless silver plating for SERS enhancement studies. The experimental results show extremely strong SERS signals due to plasmonic coupling between the NWs, which was verified by COMSOL electric field simulations. We also compared the SERS enhancement intensity of aligned and random ZnO NWs, indicating that the aligned NWs show much stronger and repeatable SERS signal than those grown in nonaligned geometries.

  16. European Vertical Reference System Influence in Latvia

    Science.gov (United States)

    Celms, A.; Reķe, I.; Ratkevičs, A.

    2015-11-01

    Till 1 December, 2014, in Latvia the heights were determined in Baltic Normal Height System 1977. The national height system is determined by the Cabinet of Ministers and internal laws. Now for the change of the national height system to reconcile it with the European Vertical Reference System, amendments to the laws and regulations have been developed, but so far only the amendment to the Geospatial Information Law is in force, the amendment to the regulation of the Cabinet of Ministers is still not approved. This amendment declares the Latvia Height System based on the European Vertical Reference System in Latvia as the national height system. For height transformation, there is a transformation formula for each European country. After calculations it is seen that height difference between Baltic Normal Height System 1977 and European Vertical Reference System depends on point location in the territory (coordinates). This unequal height difference between both height systems will cause unequal height values on border connection points between Baltic countries. The aim of the research is to evaluate the European Vertical Reference System in Latvia. To reach the aim the following tasks are set: 1) to evaluate the components of transformation formulas; 2) using the transformation formulas to calculate height differences between Baltic Normal Height System 1977 and the European Vertical Reference System realization EVRF2007 for the territory of Latvia and also between Baltic Normal Height System 1977 and the Latvia Normal Height System; 3) to get height differences in the European Vertical Reference System on the borderlines of Latvia - Estonia and Latvia - Lithuania.

  17. The Revolutionary Vertical Lift Technology (RVLT) Project

    Science.gov (United States)

    Yamauchi, Gloria K.

    2018-01-01

    The Revolutionary Vertical Lift Technology (RVLT) Project is one of six projects in the Advanced Air Vehicles Program (AAVP) of the NASA Aeronautics Research Mission Directorate. The overarching goal of the RVLT Project is to develop and validate tools, technologies, and concepts to overcome key barriers for vertical lift vehicles. The project vision is to enable the next generation of vertical lift vehicles with aggressive goals for efficiency, noise, and emissions, to expand current capabilities and develop new commercial markets. The RVLT Project invests in technologies that support conventional, non-conventional, and emerging vertical-lift aircraft in the very light to heavy vehicle classes. Research areas include acoustic, aeromechanics, drive systems, engines, icing, hybrid-electric systems, impact dynamics, experimental techniques, computational methods, and conceptual design. The project research is executed at NASA Ames, Glenn, and Langley Research Centers; the research extensively leverages partnerships with the US Army, the Federal Aviation Administration, industry, and academia. The primary facilities used by the project for testing of vertical-lift technologies include the 14- by 22-Ft Wind Tunnel, Icing Research Tunnel, National Full-Scale Aerodynamics Complex, 7- by 10-Ft Wind Tunnel, Rotor Test Cell, Landing and Impact Research facility, Compressor Test Facility, Drive System Test Facilities, Transonic Turbine Blade Cascade Facility, Vertical Motion Simulator, Mobile Acoustic Facility, Exterior Effects Synthesis and Simulation Lab, and the NASA Advanced Supercomputing Complex. To learn more about the RVLT Project, please stop by booth #1004 or visit their website at https://www.nasa.gov/aeroresearch/programs/aavp/rvlt.

  18. Lateral and Vertical Organic Transistors

    Science.gov (United States)

    Al-Shadeedi, Akram

    An extensive study has been performed to provide a better understanding of the operation principles of doped organic field-effect transistors (OFETs), organic p-i-n diodes, Schottky diodes, and organic permeable base transistors (OPBTs). This has been accomplished by a combination of electrical and structural characterization of these devices. The discussion of doped OFETs focuses on the shift of the threshold voltage due to increased doping concentrations and the generation and transport of minority charge carriers. Doping of pentacene OFETs is achieved by co-evaporation of pentacene with the n-dopant W2(hpp)4. It is found that pentacene thin film are efficiently doped and that a conductivity in the range of 2.6 x 10-6 S cm-1 for 1 wt% to 2.5 x 10-4 S cm-1 for 16 wt% is reached. It is shown that n-doped OFET consisting of an n-doped channel and n-doped contacts are ambipolar. This behavior is surprising, as n-doping the contacts should suppress direct injection of minority charge carriers (holes). It was proposed that minority charge carrier injection and hence the ambipolar characteristic of n-doped OFETs can be explained by Zener tunneling inside the intrinsic pentacene layer underneath the drain electrode. It is shown that the electric field in this layer is indeed in the range of the breakdown field of pentacene based p-i-n Zener homodiodes. Doping the channel has a profound influence on the onset voltage of minority (hole) conduction. The onset voltage can be shifted by lightly n-doping the channel. The shift of onset voltage can be explained by two mechanisms: first, due to a larger voltage that has to be applied to the gate in order to fully deplete the n-doped layer. Second, it can be attributed to an increase in hole trapping by inactive dopants. Moreover, it has been shown that the threshold voltage of majority (electron) conduction is shifted by an increase in the doping concentration, and that the ambipolar OFETs can be turned into unipolar OFETs at

  19. Tropopause Height's influences on vertical ozone structure in Ankara, Turkey

    Science.gov (United States)

    Demirhan, D.; Kahya, C.; Topcu, S.; Incecik, S.

    2003-04-01

    The changes in ozone and the temperature profiles in mid-latitudes of lower stratosphere are consistent with the assumption of a change in vertical transport. The variability of total ozone in these latitudes may be related to the tropopause heights. Stratospheric ozone observations based on balloon-borne ozonesonde from Ankara (40^oN;33^oE) by Turkish State Meteorological Service (TSMS) began in January 1994. The measurement program is currently continuing at taken State Meteorological Station. The ECC ozonesonde has been used by chemical means as the instrument ascents through the atmosphere by balloon. In this study, we attempt to present the results of analyses of tropopause heights and their influences on total ozone variability in Ankara. Due to the strong dynamical processes, and associated atmospheric transport, which are the main reasons of the variability in the vertical ozone profiles in mid-latitudes, the tropopause heights and temperature and ozone mixing ratio profiles in Ankara were examined. It is founded that the average value of total column ozone amount by ozonesounding is 320 DU with a standard deviation ± 43 in the period of 1994-2001 in Ankara. The monthly average total column ozone varied in between 250 to 419 DU. In this study, we have considered a classification of the observed data according to the low and high tropopause heights corresponding to ozone mixing ratio profiles for the winter (DJF) and the summer (JJA). For this purpose we assumed a range in between 8.5-10.0 km heights for low tropopause; 10.0 km and higher for high tropopause respectively. About 151 soundings from January 1994 to December 2001 are used in this analysis. Of all 151 sounding used, 47 fall in winter period and 29 in summer period. Furthermore 43 from total sounding correspond to the lower tropopause height and 108 to the higher class. Furthermore, the average ozone mixing ratio profiles for the low and high tropopause groups are obtained. The correlation

  20. Multiport well design for sampling of ground water at closely spaced vertical intervals

    Science.gov (United States)

    Delin, G.N.; Landon, M.K.

    1996-01-01

    Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected. Samples can be collected at closely spaced vertical intervals from nested wells with short screened intervals. However, this approach may not be appropriate in all situations. An easy-to-construct and easy-to-install multiport sampling well to collect ground-water samples from closely spaced vertical intervals was developed and tested. The multiport sampling well was designed to sample ground water from surficial sand-and-gravel aquifers. The device consists of multiple stainless-steel tubes within a polyvinyl chloride (PVC) protective casing. The tubes protrude through the wall of the PVC casing at the desired sampling depths. A peristaltic pump is used to collect ground-water samples from the sampling ports. The difference in hydraulic head between any two sampling ports can be measured with a vacuum pump and a modified manometer. The usefulness and versatility of this multiport well design was demonstrated at an agricultural research site near Princeton, Minnesota where sampling ports were installed to a maximum depth of about 12 m below land surface. Tracer experiments were conducted using potassium bromide to document the degree to which short-circuiting occurred between sampling ports. Samples were successfully collected for analysis of major cations and anions, nutrients, selected herbicides, isotopes, dissolved gases, and chlorofluorcarbon concentrations.

  1. Vertical Distribution of Dust and Water Ice Aerosols from CRISM Limb-geometry Observations

    Science.gov (United States)

    Smith, Michael Doyle; Wolff, Michael J.; Clancy, Todd; Kleinbohl, Armin; Murchie, Scott L.

    2013-01-01

    [1] Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board the Mars Reconnaissance Orbiter provide a useful tool for probing atmospheric structure. Specifically, the observed radiance as a function of wavelength and height above the limb enables the vertical distribution of both dust and water ice aerosols to be retrieved. More than a dozen sets of CRISM limb observations have been taken so far providing pole-to-pole cross sections, spanning more than a full Martian year. Radiative transfer modeling is used to model the observations taking into account multiple scattering from aerosols and the spherical geometry of the limb observations. Both dust and water ice vertical profiles often show a significant vertical structure for nearly all seasons and latitudes that is not consistent with the well-mixed or Conrath-v assumptions that have often been used in the past for describing aerosol vertical profiles for retrieval and modeling purposes. Significant variations are seen in the retrieved vertical profiles of dust and water ice aerosol as a function of season. Dust typically extends to higher altitudes (approx. 40-50km) during the perihelion season than during the aphelion season (water ice clouds are common, and water ice aerosols are observed to cap the dust layer in all seasons.

  2. Effects Of Whole Body Vibration On Vertical Jump Performance Following Exercise Induced Muscle Damage

    Directory of Open Access Journals (Sweden)

    Nicole C. Dabbs

    2014-01-01

    Full Text Available Enhancing vertical jump performance is critical for many sports. Following high intensity training, individuals often experience exercise induced muscle damage (EIMD. Many recovery modalities have been tested with conflicting results. The purpose of this investigation was to determine the effect of whole-body vibration (WBV on vertical jump performance following EIMD. 27 females volunteered for 7 sessions and were randomly assigned to a treatment or control group and administered each testing day. Vertical jump performance was assessed via vertical jump height (VJH, peak power output (PPO, rate of force development (RFD, relative ground reaction force (GRFz, and peak activation ratio of the vastus medialis (VM via electromyography (EMG before and after 3 days of EIMD via split squats. Two testing sets were collected each day, consisting of pre measures followed by WBV or control, and then post second measures. A 2x8 (group x time mixed factor analysis of variance (ANOVA was conducted for each variable. No significant interactions or group differences were found in any variable. Significant main effects for time were found in any variable, indicating performance declined following muscle damage. These results indicate that WBV does not aid in muscle recovery or vertical jump performance following EIMD.

  3. Medical Care at a Large Vertical Running Event.

    Science.gov (United States)

    Nash, Christopher J; Richards, Christopher T; Schwieger, Gina; Malik, Sanjeev; Chiampas, George T

    2018-01-01

    vertical running events, the majority of which are not life-threatening, mainly occur at the finish line but can occur at any point along the route. Understanding the nature and location of medical encounters along a vertical running event route can help inform event medical directors supervising care at these increasingly popular events.

  4. ADVANCED MIXING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in

  5. THE MARKETING MIX OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    SABOU FELICIA

    2014-02-01

    Full Text Available ing mix a particularly important issue is to choose the best combination of its variables, this lead to the achievement objectives, in time. Choosing the right marketing mix is possible only by reporting information to some clear benchmarks, these criteria a related to the objective of the company at the time of analyze. The study shows that the companies must give a great importance to optimize the marketing mix, because of how its combines and integrates company policies relating to the product, price, distribution and promotion, depends the success or the failure on its market. The practice has shown that if an element of the marketing mix is wrong implemented, marketing strategies and programs do not achieve their objectives, and the company can not generate the expected profit. To optimize the marketing mix, companies should consider the following issues: the resources (materials, financial and human, which will be properly allocated to all the elements of the marketing mix, the specific marketing tools and the relationship of interdependence of all the methods and tools used to optimize the marketing mix.

  6. Confocal profilometer with nanometric vertical resolution

    International Nuclear Information System (INIS)

    Butler, D.J.; Horsfall, A.; Hrynevych, M.; Kearney, P.D.; Nugent, K.A.

    1992-01-01

    An optical system is described which is based on the method of Kobayashi et al. The instrument is capable of simultaneous confocal imaging and profilometry with nanometric (nm) vertical resolution. The profile is independent of the reflectivity of the sample and is obtained by raster-scanning the sample without active feedback. It is shown that the vertical resolution of this technique may be extended down to 1 nm and have recorded images with a resolution of better than 3 nm. The concept and design is considerably simpler than most optical profilometers and may represent the most affordable method of profilometry with nanometric resolution available. 15 refs., 6 figs

  7. Geophysical aspects of vertical streamer seismic data

    Energy Technology Data Exchange (ETDEWEB)

    Sognnes, Walter

    1998-12-31

    Vertical cable acquisition is performed by deploying a certain number of vertical hydrophone arrays in the water column, and subsequently shooting a source point on top of it. The advantage of this particular geometry is that gives a data set with all azimuths included. Therefore a more complete 3-D velocity model can be derived. In this paper there are presented some results from the Fuji survey in the Gulf of Mexico. Based on these results, improved geometries and review recommendations for future surveys are discussed. 7 figs.

  8. Certified standards and vertical coordination in aquaculture

    DEFF Research Database (Denmark)

    Trifkovic, Neda

    2014-01-01

    This paper explores the interaction between food standards and vertical coordination in the Vietnamese pangasius sector. For farmers and processors alike, the adoption of standards is motivated by a desire to improve market access by ensuring high quality supply. Instead of encouraging...... the application of standards and contract farming, processing companies prefer to vertically integrate primary production largely due to concerns over the stable supply of pangasius with satisfactory quality and safety attributes. These tendencies increase the market dominance of industrial farming and worsen...

  9. Thermal Stratification in Vertical Mantle Tanks

    DEFF Research Database (Denmark)

    Knudsen, Søren; Furbo, Simon

    2001-01-01

    are carried out to investigate how the thermal stratification is affected by different placements of the mantle inlet. The heat transfer between the solar collector fluid in the mantle and the domestic water in the inner tank is analysed by CFD-simulations. Furthermore, the flow pattern in the vertical mantle......It is well known that it is important to have a high degree of thermal stratification in the hot water storage tank to achieve a high thermal performance of SDHW systems. This study is concentrated on thermal stratification in vertical mantle tanks. Experiments based on typical operation conditions...

  10. Measurement of the CKM matrix element vertical stroke Vts vertical stroke 2

    International Nuclear Information System (INIS)

    Unverdorben, Christopher Gerhard

    2015-03-01

    This is the first direct measurement of the CKM matrix element vertical stroke V ts vertical stroke, using data collected by the ATLAS detector in 2012 at √(s)= 8 TeV pp-collisions with a total integrated luminosity of 20.3 fb -1 . The analysis is based on 112 171 reconstructed t anti t candidate events in the lepton+jets channel, having a purity of 90.0 %. 183 t anti t→W + W - b anti s decays are expected (charge conjugation implied), which are available for the extraction of the CKM matrix element vertical stroke V ts vertical stroke 2 . To identify these rare decays, several observables are examined, such as the properties of jets, tracks and of b-quark identification algorithms. Furthermore, the s-quark hadrons K 0 s are considered, reconstructed by a kinematic fit. The best observables are combined in a multivariate analysis, called ''boosted decision trees''. The responses from Monte Carlo simulations are used as templates for a fit to data events yielding a significance value of 0.7σ for t→s+W decays. An upper limit of vertical stroke V ts vertical stroke 2 <1.74 % at 95 % confidence level is set, including all systematic and statistical uncertainties. So this analysis, using a direct measurement of the CKM matrix element vertical stroke V ts vertical stroke 2 , provides the best direct limit on vertical stroke V ts vertical stroke 2 up to now.

  11. Is the tri-bimaximal mixing accidental?

    CERN Document Server

    Abbas, Mohammed

    2010-01-01

    The Tri-bimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on structure of the neutrino mass matrix and on underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM mass relations. As a result, the mass matrix may have an "anarchical" structure with random values of elements or it may have some symmetry which differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain "flavor alignment" as well as hierarchical matrices with a two-component structure, where the dominant and sub-dominant contributions have different symmetries. This opens up new approaches to understand the lepton mixing.

  12. Optimizing the strategic patient mix combining queueing theory and dynamic programming

    NARCIS (Netherlands)

    Vanberkel, Peter T.; Boucherie, Richardus J.; Hans, Elias W.; Hurink, Johann L.

    2014-01-01

    In this paper we address the decision of choosing a patient mix for a hospital that leads to the most beneficial treatment case mix. We illustrate how capacity, case mix and patient mix decisions are interrelated and how understanding this complex relationship is crucial for achieving the maximum

  13. 33 CFR 118.85 - Lights on vertical lift bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of the...

  14. Variability of Vertical Velocity Statistics in the Cloud-Free Convective Boundary Layer as Revealed by Doppler Lidar

    Science.gov (United States)

    Berg, L. K.; Newsom, R. K.; Turner, D. D.

    2016-12-01

    The majority of our understanding of the behavior of vertical velocity in the convective boundary layer is based on a small number of short-term observations made using either in situ or with remote sensing techniques over a limited number of sites. Analysis of long-term statistics have been lacking due to the scarcity of appropriate measurements. The US Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is addressing this shortcoming through the deployment of a suite of scanning Doppler Lidars at a number of locations, associated with reconfiguration of the ARM Southern Great Plains site and the recent Holistic Interaction of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) field campaign. In this study, we utilize data collected by a Doppler Lidar system that has operated continuously from 2011 to the present at a location in north-central Oklahoma to examine the long-term behavior of the vertical velocity variance, skewness, and kurtosis. The application of standard normalization techniques, such as the mixed-layer depth and Deardorff convective velocity scale, do a good job in collapsing the data onto a single curve during periods in which the boundary layer is well developed, albeit with considerable amounts of scatter. During non-steady conditions, such as those found in the morning, scaling using the Deardorff convective velocity scale is found to work poorly. This behavior is likely due to the eddy turnover time and the growth rate of the boundary-layer depth. Systematic differences in the turbulence statistics are found by season, for non-stationary conditions, or periods with relatively small and large values of the surface friction velocity measured at the surface, amount of static instability, and wind shear across the boundary-layer top.

  15. Volatile organic compound mixing ratios above Beijing in November and December 2016

    Science.gov (United States)

    Acton, William; Shaw, Marvin; Huang, Zhonghui; Wang, Zhaoyi; Wang, Xinming; Zhang, Yanli; Davison, Brian; Langford, Ben; Mullinger, Neil; Nemitz, Eiko; Fu, Pingqing; Squires, Freya; Carpenter, Lucy; Lewis, Alastair; Hewitt, Nick

    2017-04-01

    Volatile organic compounds (VOCs) are emitted into the atmosphere from vegetation and anthropogenic sources such as fossil fuel combustion, biomass burning and the evaporation of petroleum products. These compounds play an important role in the chemistry of the lower atmosphere through secondary organic aerosol (SOA) formation and facilitating the formation of tropospheric ozone. As well as their indirect impact on human health via the formation of ozone and SOA, some VOCs, including benzene, directly affect human health adversely. Here we report VOC mixing ratios measured in Beijing during a 5 week intensive field campaign from the 7th November to the 10th December 2016. This work was carried out as part of the Sources and Emissions of Air Pollutants in Beijing (AIRPOLL-Beijing) work project within the Air Pollution and Human Health in a Developing Megacity (APHH-Beijing) research programme. APHH is a large multi-institutional study which aims to record the concentrations and identify the sources of urban air pollutants in Beijing, determine exposure, understand their effects on human health, and to identify solutions. VOC mixing ratios were recorded using a Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToF-MS, Ionicon Analytik) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS, SYFT Technologies). During the measurement period Beijing was subject to multiple pollution events that alternated with periods of relatively good air quality, allowing the VOCs within the polluted air masses to be identified and quantified. VOCs were sampled at 102 m with additional gradient measurements made at 3, 15, 32 and 64 m providing a vertical profile of VOC mixing ratios. Mixing ratios of methanol, acetonitrile, acetaldehyde, acetone, isoprene and aromatics species will be reported together with a discussion of potential sources. Comparisons will then be drawn with other large cities.

  16. Wind, hydro or mixed renewable energy source

    DEFF Research Database (Denmark)

    Yang, Yingkui; Solgaard, Hans Stubbe; Haider, Wolfgang

    2016-01-01

    While the share of renewable energy, especially wind power, increases in the energy mix, the risk of temporary energy shortage increases as well. Thus, it is important to understand consumers' preference for the renewable energy towards the continuous growing renewable energy society. We use...

  17. Modulating fracture properties of mixed protein systems

    NARCIS (Netherlands)

    Ersch, C.E.; Laak, I. ter; Linden, E. van der; Venema, P.; Martin, A.H.

    2015-01-01

    To design foods with desired textures it is important to understand structure build-up and breakdown. One can obtain a wide range of structures using mixtures of different structuring ingredients such as for example protein mixtures. Mixed soy protein isolate (SPI)/gelatine gels were analyzed for

  18. Investigating mixed phase clouds using a synergy of ground based remote sensing measurements

    Science.gov (United States)

    Gierens, Rosa; Kneifel, Stefan; Löhnert, Ulrich

    2017-04-01

    Low level mixed phase clouds occur frequently in the Arctic, and can persist from hours to several days. However, the processes that lead to the commonality and persistence of these clouds are not well understood. The aim of our work is to get a more detailed understanding of the dynamics of and the processes in Arctic mixed phase clouds using a combination of instruments operating at the AWIPEV station in Svalbard. In addition, an aircraft campaign collecting in situ measurements inside mixed phase clouds above the station is planned for May-June 2017. The in situ data will be used for developing and validating retrievals for microphysical properties from Doppler cloud radar measurements. Once observational data for cloud properties is obtained, it can be used for evaluating model performance, for studies combining modeling and observational approaches, and eventually lead to developing model parameterizations of mixed phase microphysics. To describe the low-level mixed phase clouds, and the atmospheric conditions in which they occur, we present a case study of a persistent mixed phase cloud observed above the AWIPEV station. In the frame of the Arctic Amplification: Climate Relevant Atmospheric and Surface Processes and Feedback Mechanisms ((AC)3) -project, a millimeter wavelength cloud radar was installed at the site in June 2016. The high vertical (4 m in the lowest layer) and temporal (2.5 sec) resolution allows for a detailed description of the structure of the cloud. In addition to radar reflectivity and mean vertical velocity, we also utilize the higher moments of the Doppler spectra, such as skewness and kurtosis. To supplement the radar measurements, a ceilometer is used to detect liquid layers inside the cloud. Liquid water path and integrated water vapor are estimated using a microwave radiometer, which together with soundings can also provide temperature and humidity profiles in the lower troposphere. Moreover, a three-dimensional wind field is be

  19. Guidelines for mixed waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization.

  20. Guidelines for mixed waste minimization

    International Nuclear Information System (INIS)

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization

  1. Estimation of In-canopy Flux Distributions of Reactive Nitrogen and Sulfur within a Mixed Hardwood Forest in Southern Appalachia

    Science.gov (United States)

    Wu, Z.; Walker, J. T.; Chen, X.; Oishi, A. C.; Duman, T.

    2017-12-01

    Estimating the source/sink distribution and vertical fluxes of air pollutants within and above forested canopies is critical for understanding biological, physical, and chemical processes influencing the soil-vegetation-atmosphere exchange. The vertical source-sink profiles of reactive nitrogen and sulfur were examined using multiple inverse modeling methods in a mixed hardwood forest in the southern Appalachian Mountains where the ecosystem is highly sensitive to loads of pollutant from atmospheric depositions. Measurements of the vertical concentration profiles of ammonia (NH3), nitric acid (HNO3), sulfur dioxide (SO2), and ammonium (NH4+), nitrate (NO3-), and sulfate (SO42-) in PM2.5 were measured during five study periods between May 2015 and August 2016. The mean concentration of NH3 decreased with height in the upper canopy and increased below the understory toward the forest floor, indicating that the canopy was a sink for NH3 but the forest floor was a source. All other species exhibited patterns of monotonically decreasing concentration from above the canopy to the forest floor. Using the measured concentration profiles, we simulated the within-canopy flow fields and estimated the vertical source-sink flux profiles using three inverse approaches: a Eulerian high-order closure model (EUL), a Lagrangian localized near-field (LNF) model, and a new full Lagrangian stochastic model (LSM). The models were evaluated using the within- and above-canopy eddy covariance flux measurements of heat, CO2 and H2O. Differences between models were analyzed and the flux profiles were used to investigate the origin and fate of reactive nitrogen and sulfur compounds within the canopy. The knowledge gained in this study will benefit the development of soil-vegetation-atmosphere models capable of partitioning canopy-scale deposition of nitrogen and sulfur to specific ecosystem compartments.

  2. SPORT MARKETING MIX STRATEGIES

    Directory of Open Access Journals (Sweden)

    Alexandru Lucian MIHAI

    2013-06-01

    Full Text Available This paper presents a brief overview of a significant element of the sport marketing management model called the marketing mix. The marketing mix is crucial because it defines the sport business, and much of the sport marketer’s time is spent on various functions within the marketing mix. The marketing mix is the strategic combination of the product, price, place and promotion elements. These elements are typically called the four Ps of marketing. Decisions and strategies for each are important for the marketer. Information for making educated decisions involving the four Ps comes from the marketing research involving primarily the four Cs - consumer, competitor, company and climate. A critical decision and one of the greatest challenges for the sport business is how to strategically combine the four Ps to best satisfy the consumer, meet company objectives, enhance market position, and enhance competitive advantages.

  3. News on Deep Mixing

    Science.gov (United States)

    Lattanzio, John C.; Dearborn, Davis S. P.; Eggleton, Peter P.

    2008-04-01

    We briefly summarize the abundant observational evidence for the need of a ``deep mixing'' mechanism in first-ascent red-giant stars, and probably in AGB stars as well. By the term ``deep mixing'' we mean some mixing mechanism which operates in the radiative zone below the convective envelope, and which transports material from the convective region to hotter regions, near the top of the hydrogen shell, where nuclear burning may take place. We then discuss a recent discovery of deep-mixing caused by the burning of 3He following first dredge-up in low-mass stars. This is expected to be a thermohaline process and preliminary calculations show that it has many of the properties required to explain the observations.

  4. Investigating the role of air-sea forcing on the variability of hydrography, circulation, and mixed layer depth in the Arabian Sea and Bay of Bengal

    Directory of Open Access Journals (Sweden)

    Atul Srivastava

    2018-04-01

    Full Text Available Summary: An effort is made to understand and quantify the influence of near surface zonal and meridional winds, incoming shortwave radiation, and freshwater flux air-sea forcings on the seasonal variability of the hydrography, circulation, and mixed layer depth of the Arabian Sea (AS and Bay of Bengal (BoB. Sensitivity experiments using an ocean general circulation model are carried out for this purpose in the Indian ocean around 65°–95°E, 5°–22°N during 1998–2014 (17 years. In the absence of near surface wind forcing, the sea surface temperature of the region greatly increases in all the seasons, whereas, in the absence of incoming shortwave radiation forcing, exactly opposite is the case. The sea surface salinity of the AS and BoB decreases in the absence of wind and shortwave radiation forcings, whereas, in the northern BoB it increases in the absence of freshwater flux forcing. The sub-surface changes in the stratification of temperature and salinity are also investigated. The influence of the air-sea forcings on the mixed layer depth of the region is found to be highly seasonally dependent. The effect of air-sea forcings on the seasonal variability of the upper ocean vertical stability is studied using the vertical shear of the horizontal velocity, buoyancy frequency, and energy required for mixing as quantifiers. The near surface wind forcing has highest contribution in changing the surface circulation of the region. Keywords: Arabian Sea and Bay of Bengal, Air-sea forcing, Ocean general circulation model, Hydrography and circulation, Vertical stability

  5. A comparison of mixing depths observed over horizontally inhomogeneous terrain

    Energy Technology Data Exchange (ETDEWEB)

    White, A.B. [Univ. of Colorado/NOAA Environmental Technology Lab., Cooperative Inst. for Research in Environmental Sciences, Boulder, CO (United States); King, C.W. [NOAA Environmental Technology Lab., Boulder, CO (United States)

    1997-10-01

    In this paper we used wind profiler observations to estimate the mixing depth on either side of the Continental Divide on days when a PTBC (plain-to-basin-circulation) occurred along the Front Range of Colorado during the summer of 1995. The mixing depths on the basin side were significantly deeper than the mountain barrier for all of the PTBC events we analyzed. On the plains side, the mixed layers often extended to or above the level of the mountain barrier. On certain days up-slope flow existed above the mixed layer. We depicted the vertical structure of the flow and features in the humidity profile on one of these days using measurements from a wind profiler. The results were consistent with the conceptual model presented by Wolyn and McKee (1994). (au)

  6. The Robustness of IRT-Based Vertical Scaling Methods to Violation of Unidimensionality

    Science.gov (United States)

    Yin, Liqun

    2013-01-01

    In recent years, many states have adopted Item Response Theory (IRT) based vertically scaled tests due to their compelling features in a growth-based accountability context. However, selection of a practical and effective calibration/scaling method and proper understanding of issues with possible multidimensionality in the test data is critical to…

  7. Phase diagram of vertically shaken ganular matter

    NARCIS (Netherlands)

    Eshuis, P.G.; Eshuis, Peter; van der Weele, J.P.; van der Meer, Roger M.; Bos, Robert; Lohse, Detlef

    2007-01-01

    A shallow, vertically shaken granular bed in a quasi-two-dimensional container is explored experimentally yielding a wider variety of phenomena than in any previous study: (1) bouncing bed, (2) undulations, (3) granular Leidenfrost effect, (4) convection rolls, and (5) granular gas. These phenomena

  8. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS-. P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation coefficient (Kd) and an optical ...

  9. MHD stability of vertically asymmetric tokamak equilibria

    International Nuclear Information System (INIS)

    Dalhed, H.E.; Grimm, R.C.; Johnson, J.L.

    1981-03-01

    The ideal MHD stability properties of a special class of vertically asymmetric tokamak equilibria are examined. The calculations confirm that no major new physical effects are introduced and the modifications can be understood by conventional arguments. The results indicate that significant departures from up-down symmetry can be tolerated before the reduction in β becomes important for reactor operation

  10. Manufacturing: the new case for vertical integration

    NARCIS (Netherlands)

    Kumpe, Ted; Bolwijn, Piet

    1988-01-01

    The article argues that the solid corporation will continue to view vertical integration as a critical part of manufacturing reform. Manufacturing reform and backward integration are related in insidious ways to the three stages of production over which the big manufacturers preside. Without

  11. Electrostatic comb drive for vertical actuation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A. P., LLNL

    1997-07-10

    The electrostatic comb finger drive has become an integral design for microsensor and microactuator applications. This paper reports on utilizing the levitation effect of comb fingers to design vertical-to-the-substrate actuation for interferometric applications. For typical polysilicon comb drives with 2 {micro}m gaps between the stationary and moving fingers, as well as between the microstructures and the substrate, the equilibrium position is nominally 1-2 {micro}m above the stationary comb fingers. This distance is ideal for many phase shifting interferometric applications. Theoretical calculations of the vertical actuation characteristics are compared with the experimental results, and a general design guideline is derived from these results. The suspension flexure stiffnesses, gravity forces, squeeze film damping, and comb finger thicknesses are parameters investigated which affect the displacement curve of the vertical microactuator. By designing a parallel plate capacitor between the suspended mass and the substrate, in situ position sensing can be used to control the vertical movement, providing a total feedback-controlled system. Fundamentals of various capacitive position sensing techniques are discussed. Experimental verification is carried out by a Zygo distance measurement interferometer.

  12. Vertical strategic alignment and public service performance

    NARCIS (Netherlands)

    Andrews, R.; Boyne, G.A.; Meier, K.J.; O'Toole, Laurence J.; Walker, R.M.

    2012-01-01

    We report the results of a study examining the effects of vertical strategic alignment (that is, the degree to which strategic stances are consistent across different organizational levels) on public service performance. Longitudinal multivariate analysis is undertaken on a panel of public

  13. Integrated Vertical Photobioreactor System for Carbon Dioxide ...

    African Journals Online (AJOL)

    A vertical photobioreactor containing the microalgae Scenedesmus obliquus is a highly efficient system for converting carbon dioxide (CO2) into biomass. The use of photobioreactor for CO2 mitigation has been explored using microalgae as photosynthetic microorganism. The growth rate (m, h-1) were 0.03; 0.13; 0.20; 0.09 ...

  14. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS- P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation Coeffcient () and an optical ...

  15. Determinants Of Vertical And Horizontal Export Diversification ...

    African Journals Online (AJOL)

    The intuition is that East Asian countries have devoted significant amount of investment on education, health, infrastructure and these in turn created a better conducive atmosphere for FDI inflow. The study also reveals domestic investment plays an important role to enhance vertical as well as horizontal export diversification ...

  16. Vertical reflector for bifacial PV-panels

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

    2016-01-01

    Bifacial solar modules offer an interesting price/performance ratio, and much work has been focused on directing the ground albedo to the back of the solar cells. In this work we design and develop a reflector for a vertical bifacial panel, with the objective to optimize the energy harvest...

  17. Optical anisotropy in vertically coupled quantum dots

    DEFF Research Database (Denmark)

    Yu, Ping; Langbein, Wolfgang Werner; Leosson, Kristjan

    1999-01-01

    We have studied the polarization of surface and edge-emitted photoluminescence (PL) from structures with vertically coupled In0.5Ga0.5As/GaAs quantum dots (QD's) grown by molecular beam epitaxy. The PL polarization is found to be strongly dependent on the number of stacked layers. While single...... number due to increasing dot size....

  18. Vertical coordination and cooperative member benefits

    NARCIS (Netherlands)

    Zhong, Zhen; Zhang, Chen; Jia, Fu; Bijman, Jos

    2018-01-01

    Agricultural cooperatives have grown exponentially in the past few decades. There is anecdotal evidence showing that vertical coordination of cooperatives with upstream and downstream supply chain bring benefits to cooperative members; however this relationship is far from clear. In particular, the

  19. Evaluation of vertical parameters in cephalometry.

    Science.gov (United States)

    Bock, Jens Johannes; Fuhrmann, Robert A W

    2007-05-01

    The aim of this study was to determine the validity of different vertical parameters in cephalometry. The cephalograms of 94 patients were used in this study. The inclusion criteria were as follows: skeletal Class I, completion of maximum skeletal growth, and no history of orthodontic therapy. The control group consisted of 34 subjects with very good occlusion (overbite 2-4 mm). The patients were classified with the help of dental casts: Group 1 (n = 31) patients with cover-bite (overbite > 5.5 mm) and Group 2 (n = 29) patients with anterior open bite (overbite < -0.5 mm). In addition to the 24 standard cephalometric measurements (Bergen-Analysis), we included individualized norm values (Segner & Hasund), the Overbite Depth Indicator (ODI) described by Kim, the Denture Frame Analysis (DFA) described by Sato, and facial-type evaluations according to Schopf. We observed significant differences among the three study groups in all the vertical parameters tested. We demonstrated statistically-significant classification results for the Segner & Hasund harmony box's individualized norm values (83.8%), and those of the ODI (77.7%) and ML-AB angle (76.6%). Based on the vertical cephalometric parameters, we succeeded in statistically differentiating among the groups with open bite, cover-bite and the control group. Various measurements must be taken to ensure that the cephalometric vertical relationships are reliably evaluated.

  20. Vertical integration of HRD policy within companies

    NARCIS (Netherlands)

    Wognum, Ida

    2001-01-01

    This study concerns HRD policy making in companies. More specifically, it explores whether so-called vertical integration of HRD policy at different organizational levels occurs within companies. The study involved forty-four large companies in the industrial and the financial and commercial