WorldWideScience

Sample records for barriers scale

  1. Large-scale field testing on flexible shallow landslide barriers

    Science.gov (United States)

    Bugnion, Louis; Volkwein, Axel; Wendeler, Corinna; Roth, Andrea

    2010-05-01

    Open shallow landslides occur regularly in a wide range of natural terrains. Generally, they are difficult to predict and result in damages to properties and disruption of transportation systems. In order to improve the knowledge about the physical process itself and to develop new protection measures, large-scale field experiments were conducted in Veltheim, Switzerland. Material was released down a 30° inclined test slope into a flexible barrier. The flow as well as the impact into the barrier was monitored using various measurement techniques. Laser devices recording flow heights, a special force plate measuring normal and shear basal forces as well as load cells for impact pressures were installed along the test slope. In addition, load cells were built in the support and retaining cables of the barrier to provide data for detailed back-calculation of load distribution during impact. For the last test series an additional guiding wall in flow direction on both sides of the barrier was installed to achieve higher impact pressures in the middle of the barrier. With these guiding walls the flow is not able to spread out before hitting the barrier. A special constructed release mechanism simulating the sudden failure of the slope was designed such that about 50 m3 of mixed earth and gravel saturated with water can be released in an instant. Analysis of cable forces combined with impact pressures and velocity measurements during a test series allow us now to develop a load model for the barrier design. First numerical simulations with the software tool FARO, originally developed for rockfall barriers and afterwards calibrated for debris flow impacts, lead already to structural improvements on barrier design. Decisive for the barrier design is the first dynamic impact pressure depending on the flow velocity and afterwards the hydrostatic pressure of the complete retained material behind the barrier. Therefore volume estimation of open shallow landslides by assessing

  2. Laboratory and field scale demonstration of reactive barrier systems

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Marozas, D.C.; Cantrell, K.; Stewart, W.

    1996-10-01

    In an effort to devise a cost efficient technology for remediation of uranium contaminated groundwater, the Department of Energy's Uranium Mill Tailings Remedial Action (DOE-UMTRA) Program through Sandia National Laboratories (SNL) fabricated a pilot scale research project utilizing reactive subsurface barriers at an UMTRA site in Durango, Colorado. A reactive subsurface barrier is produced by placing a reactant material (in this experiment, metallic iron) in the flow path of the contaminated groundwater. The reactive media then removes and/or transforms the contaminant(s) to regulatory acceptable levels. Experimental design and results are discussed with regard to other potential applications of reactive barrier remediation strategies at other sites with contaminated groundwater problems

  3. A cross-cultural investigation into the dimensional structure and stability of the Barriers to Research and Utilization Scale (BARRIERS Scale).

    Science.gov (United States)

    Williams, Brett; Brown, Ted; Costello, Shane

    2015-10-24

    It is important that scales exhibit strong measurement properties including those related to the investigation of issues that impact evidence-based practice. The validity of the Barriers to Research Utilization Scale (BARRIERS Scale) has recently been questioned in a systematic review. This study investigated the dimensional structure and stability of the 28 item BARRIERS Scale when completed by three groups of participants from three different cross-cultural environments. Data from the BARRIERS Scale completed by 696 occupational therapists from Australia (n = 137), Taiwan (n = 413), and the United Kingdom (n = 144) were analysed using principal components analysis, followed by Procrustes Transformation. Poorly fitting items were identified by low communalities, cross-loading, and theoretically inconsistent primary loadings, and were systematically removed until good fit was achieved. The cross-cultural stability of the component structure of the BARRIERS Scale was examined. A four component, 19 item version of the BARRIERS Scale emerged that demonstrated an improved dimensional fit and stability across the three participant groups. The resulting four components were consistent with the BARRIERS Scale as originally conceptualised. Findings from the study suggest that the four component, 19 item version of the BARRIERS Scale is a robust and valid measure for identifying barriers to research utilization for occupational therapists in paediatric health care settings across Australia, United Kingdom, and Taiwan. The four component 19 item version of the BARRIERS Scale exhibited good dimensional structure, internal consistency, and stability.

  4. Development and psychometric testing of a barriers to HIV testing scale among individuals with HIV infection in Sweden; The Barriers to HIV testing scale-Karolinska version.

    Science.gov (United States)

    Wiklander, Maria; Brännström, Johanna; Svedhem, Veronica; Eriksson, Lars E

    2015-11-19

    Barriers to HIV testing experienced by individuals at risk for HIV can result in treatment delay and further transmission of the disease. Instruments to systematically measure barriers are scarce, but could contribute to improved strategies for HIV testing. Aims of this study were to develop and test a barriers to HIV testing scale in a Swedish context. An 18-item scale was developed, based on an existing scale with addition of six new items related to fear of the disease or negative consequences of being diagnosed as HIV-infected. Items were phrased as statements about potential barriers with a three-point response format representing not important, somewhat important, and very important. The scale was evaluated regarding missing values, floor and ceiling effects, exploratory factor analysis, and internal consistencies. The questionnaire was completed by 292 adults recently diagnosed with HIV infection, of whom 7 were excluded (≥9 items missing) and 285 were included (≥12 items completed) in the analyses. The participants were 18-70 years old (mean 40.5, SD 11.5), 39 % were females and 77 % born outside Sweden. Routes of transmission were heterosexual transmission 63 %, male to male sex 20 %, intravenous drug use 5 %, blood product/transfusion 2 %, and unknown 9 %. All scale items had <3 % missing values. The data was feasible for factor analysis (KMO = 0.92) and a four-factor solution was chosen, based on level of explained common variance (58.64 %) and interpretability of factor structure. The factors were interpreted as; personal consequences, structural barriers, social and economic security, and confidentiality. Ratings on the minimum level (suggested barrier not important) were common, resulting in substantial floor effects on the scales. The scales were internally consistent (Cronbach's α 0.78-0.91). This study gives preliminary evidence of the scale being feasible, reliable and valid to identify different types of barriers to HIV testing.

  5. Safety Performance Evaluations for the Vehicle Based Movable Barriers Using Full Scale Crash Tests

    Directory of Open Access Journals (Sweden)

    Jin Minsoo

    2017-01-01

    Full Text Available The present study aims to develop a prototype of large-size movable barriers to protect roadside workers from incoming vehicles to the road work area with the following functions: maximization of work space in the right and left directions, convenient mobility, and minimization of impact without modification of the inside of movable barriers into traffic lanes and perform safety performance assessment on passengers through full scale crash tests. The large movable barrier was divided into folder type and telescope type and the development stage was now at the prototype phase. A full scale crash test was conducted prior to certification test at a level of 90%. The full scale crash test result showed that both types of folder type movable barrier and telescope type movable barrier satisfied the standard of the passenger safety performance evaluation at a level of 90%.

  6. The validity and reliability of the exercise benefits/barriers scale for ...

    African Journals Online (AJOL)

    The exercise barrier subscale with the lowest score was “exercise milieu”. Determining the benefits of and barriers to exercise, by using a standardized scale, plays an important role in maintaining proper levels of physical activity. The Turkish translation of the EBBS model has shown it to be an effective tool for measuring ...

  7. Mama na Mtoto: Barriers and enablers to gender, equity and scale ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Mama na Mtoto: Barriers and enablers to gender, equity and scale-up in Tanzania ... Call for new OWSD Fellowships for Early Career Women Scientists now open ... conference of McGill's Institute for the Study of International Development.

  8. Development and Validation of the Elder Learning Barriers Scale Among Older Chinese Adults.

    Science.gov (United States)

    Wang, Renfeng; De Donder, Liesbeth; De Backer, Free; He, Tao; Van Regenmortel, Sofie; Li, Shihua; Lombaerts, Koen

    2017-12-01

    This study describes the development and validation of the Elder Learning Barriers (ELB) scale, which seeks to identify the obstacles that affect the level of educational participation of older adults. The process of item pool design and scale development is presented, as well as the testing and scale refinement procedure. The data were collected from a sample of 579 older Chinese adults (aged over 55) in the Xi'an region of China. After randomly splitting the sample for cross-validation purposes, the construct validity of the ELB scale was confirmed containing five dimensions: dispositional, informational, physical, situational, and institutional barriers. Furthermore, developmental differences in factor structure have been examined among older age groups. The results indicated that the scale demonstrated good reliability and validity. We conclude in general that the ELB scale appears to be a valuable instrument for examining the learning barriers that older Chinese citizens experience for participating in organized educational activities.

  9. Characterization and scaling of the tokamak edge transport barrier

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Philip Adrian

    2012-04-24

    The high confinement regime (H-mode) in a tokamak plasma displays a remarkable edge region. On a small spatial scale of 1-2 cm the properties of the plasma change significantly. Certain parameters vary 1-2 orders of magnitude in this region, called the pedestal. Currently, there is no complete understanding of how the pedestal forms or how it is sustained. The goal of this thesis is to contribute to the theoretical understanding of the pedestal and provide scalings towards larger machines, like ITER and DEMO. A pedestal database was built with data from different tokamaks: ASDEX Upgrade, DIIID and JET. The pedestal was characterized with the same method for all three machines. This gives the maximum value, gradient and width of the pedestal in n{sub e}, T{sub e} and T{sub i}. These quantities were analysed along with quantities derived from them, such as the pressure or the confinement time. For this purpose two parameter sets were used: normalized parameters (pressure {beta}, time {nu}{sub *}, length {rho}{sub *}, shape f{sub q}) and machine parameters (size a, magnetic field B{sub t}, plasma current I{sub p}, heating P). All results are dependent on the choice of the coordinate system: normalized poloidal flux {Psi}{sub N} and real space r/a. The most significant result, which was obtained with both parameter sets, shows a different scaling of the pedestal width for the electron temperature and the electron density. The presented scalings predict that in ITER and DEMO the temperature pedestal will be appreciably wider than the density pedestal. The pedestal top scaling for the pressure reveals differences between the electron and the ion pressure. In extrapolations this results in values for T{sub e,ped} of 4 keV (ITER) and 10 keV (DEMO), but significantly lower values for the ion temperature. A two-term method was applied to use the pedestal pressure to determine the pedestal contribution to the global confinement time {tau}{sub E}. The dependencies in the

  10. Characterization and scaling of the tokamak edge transport barrier

    International Nuclear Information System (INIS)

    Schneider, Philip Adrian

    2012-01-01

    The high confinement regime (H-mode) in a tokamak plasma displays a remarkable edge region. On a small spatial scale of 1-2 cm the properties of the plasma change significantly. Certain parameters vary 1-2 orders of magnitude in this region, called the pedestal. Currently, there is no complete understanding of how the pedestal forms or how it is sustained. The goal of this thesis is to contribute to the theoretical understanding of the pedestal and provide scalings towards larger machines, like ITER and DEMO. A pedestal database was built with data from different tokamaks: ASDEX Upgrade, DIIID and JET. The pedestal was characterized with the same method for all three machines. This gives the maximum value, gradient and width of the pedestal in n e , T e and T i . These quantities were analysed along with quantities derived from them, such as the pressure or the confinement time. For this purpose two parameter sets were used: normalized parameters (pressure β, time ν * , length ρ * , shape f q ) and machine parameters (size a, magnetic field B t , plasma current I p , heating P). All results are dependent on the choice of the coordinate system: normalized poloidal flux Ψ N and real space r/a. The most significant result, which was obtained with both parameter sets, shows a different scaling of the pedestal width for the electron temperature and the electron density. The presented scalings predict that in ITER and DEMO the temperature pedestal will be appreciably wider than the density pedestal. The pedestal top scaling for the pressure reveals differences between the electron and the ion pressure. In extrapolations this results in values for T e,ped of 4 keV (ITER) and 10 keV (DEMO), but significantly lower values for the ion temperature. A two-term method was applied to use the pedestal pressure to determine the pedestal contribution to the global confinement time τ E . The dependencies in the scaling for τ E,ped are nearly identical to the IPB98 global

  11. Large-scale fabrication of BN tunnel barriers for graphene spintronics

    International Nuclear Information System (INIS)

    Fu, Wangyang; Makk, Péter; Maurand, Romain; Bräuninger, Matthias; Schönenberger, Christian

    2014-01-01

    We have fabricated graphene spin-valve devices utilizing scalable materials made from chemical vapor deposition (CVD). Both the spin-transporting graphene and the tunnel barrier material are CVD-grown. The tunnel barrier is realized by Hexagonal boron nitride, used either as a monolayer or bilayer and placed over the graphene. Spin transport experiments were performed using ferromagnetic contacts deposited onto the barrier. We find that spin injection is still greatly suppressed in devices with a monolayer tunneling barrier due to resistance mismatch. This is, however, not the case for devices with bilayer barriers. For those devices, a spin relaxation time of ∼260 ps intrinsic to the CVD graphene material is deduced. This time scale is comparable to those reported for exfoliated graphene, suggesting that this CVD approach is promising for spintronic applications which require scalable materials

  12. Reliability and Validity of a Treatment Barriers Scale for Individuals With Alcohol Use Disorder.

    Science.gov (United States)

    Possemato, Kyle; Funderburk, Jennifer; Spinola, Suzanne; Hutchison, Dezarie; Maisto, Stephen A; Lantinga, Larry J; Oslin, David W

    2016-01-01

    Few studies have measured addiction-specific barriers to treatment. A measurement of barriers with psychometric support that has been tested in diverse samples and that assesses multiple components of addiction treatment barriers is needed to inform providers and treatment programs. This paper aims to provide an initial psychometric investigation of a measure of barriers to seeking addictions treatment. Data were collected from 196 Veterans Affairs primary care patients with Alcohol Use Disorder that participated in a randomized clinical trial. A Principal Components Analysis revealed that the 32-item Treatment Barriers Scale (TBS) can be reduced to 14 items, measuring 4 factors: stigma, dislike of the treatment process, alcohol problem identification, and logistical concerns. Acceptable internal consistent reliability (α = .64-.76) and excellent precision of alpha (α = 0.001-0.009) was found for each subscale. Support for the measure's concurrent validity was found, for example, participants who reported more motivation to reduce their drinking perceived significantly fewer barriers to care. Support for the measure's predictive validity was also found, including that more barriers were related to future drinking among all participants and less mental health and addictions treatment visits among participants in one treatment condition. Conclusions/ Importance: Our results provide initial support for the utility of the TBS-14 among primary care patients with Alcohol Use Disorder. Use of the TBS-14 could enable healthcare providers to better understand patient-specific treatment barriers, provide corrective information on treatment misconceptions, and inform individualized treatment plans that increase patient engagement in addiction services.

  13. Development and psychometric evaluation of the Dialysis patient-perceived Exercise Benefits and Barriers Scale.

    Science.gov (United States)

    Zheng, Jing; You, Li-Ming; Lou, Tan-Qi; Chen, Nian-Chang; Lai, De-Yuan; Liang, Yan-Yi; Li, Ying-Na; Gu, Ying-Ming; Lv, Shao-Fen; Zhai, Cui-Qiu

    2010-02-01

    Perceptions of exercise benefits and barriers affect exercise behavior. Because of the clinical course and treatment, dialysis patients differ from the general population in their perceptions of exercise benefits and barriers, especially the latter. At present, no valid instruments for assessing perceived exercise benefits and barriers in dialysis patients are available. Our goal was to develop and test the psychometric properties of the Dialysis patient-perceived Exercise Benefits and Barriers Scale (DPEBBS). A literature review and two focus groups were conducted to generate the initial item pool. An expert panel examined the content validity. Then, 269 Chinese hemodialysis patients were recruited by convenience sampling. Exploratory and confirmatory factor analyses were used to test construct validity. Finally, internal consistency and test-retest reliability were assessed. The expert panel determined that the content validity index was satisfactory. The final 24-item scale consisted of six factors explaining 57% of the total variance in the data. Confirmative factor analysis supported the six-factor structure and a higher-order model. Cronbach's alpha was 0.87 for the total scale, and 0.84 for test-retest reliability. The DPEBBS was a valid and reliable instrument for evaluating dialysis patients' perceived benefits and barriers to exercise. The application value of this scale remains to be investigated by increasing the sample size and evaluating patients undergoing different dialysis modalities and coming from different regions and cultural backgrounds. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Use of vegetable oil in a pilot-scale denitrifying barrier

    Science.gov (United States)

    Hunter, William J.

    2001-12-01

    Nitrate in drinking water is a hazard to both humans and animals. Contaminated water can cause methemoglobinemia and may pose a cancer risk. Permeable barriers containing innocuous oils, which stimulate denitrification, can remove nitrate from flowing groundwater. For this study, a sand tank (1.1×2.0×0.085 m in size) containing sand was used as a one-dimensional open-top scale model of an aquifer. A meter-long area near the center of the tank contained sand coated with soybean oil. This region served as a permeable denitrifying barrier. Water containing 20 mg l -1 nitrate-N was pumped through the barrier at a high flow rate, 1112 l week -1, for 30 weeks. During the 30-week study, the barrier removed 39% of the total nitrate-N present in the water. The barrier was most efficient during the first 10 weeks of the study when almost all of the nitrate and nitrogen was removed. Efficiency declined with time so that by week 30 almost no nitrate was removed by the system. Nitrite levels in the effluent water remained low throughout the study. Barriers could be used to protect groundwater from nitrate contamination or for the in situ treatment of contaminated water. At the low flow rates that exist in most aquifers, such barriers should be effective at removing nitrate from groundwater for a much longer period of time.

  15. A design study for a medium-scale field demonstration of the viscous barrier technology

    International Nuclear Information System (INIS)

    Moridis, G.; Yen, P.; Persoff, P.; Finsterle, S.; Williams, P.; Myer, L.; Pruess, K.

    1996-09-01

    This report is the design study for a medium-scale field demonstration of Lawrence Berkeley National Laboratory's new subsurface containment technology for waste isolation using a new generation of barrier liquids. The test site is located in central California in a quarry owned by the Los Banos Gravel Company in Los Banos, California, in heterogeneous unsaturated deposits of sand, silt, and -ravel typical of many of the and DOE cleanup sites and particularly analogous to the Hanford site. The coals of the field demonstration are (a) to demonstrate the ability to create a continuous subsurface barrier isolating a medium-scale volume (30 ft long by 30 ft wide by 20 ft deep, i.e. 1/10th to 1/8th the size of a buried tank at the Hanford Reservation) in the subsurface, and (b) to demonstrate the continuity, performance, and integrity of the barrier

  16. Short communication: Multi-scale topographic anisotropy patterns on a Barrier Island

    Science.gov (United States)

    Houser, Chris; Bishop, Michael; Wernette, Phil

    2017-11-01

    Barrier islands exhibit a range of landforms that reflect the complex and varied combination of coastal and aeolian processes realized over the evolution of the island. A detailed analysis of the topography can be used to describe the evolution of a barrier island and provide insight on how it may be affected by a change in sea level, storm activity and wind exposure patterns. Topographic anisotropy, or the directional dependence of relief of landforms, can be used to determine the relative importance of different processes to island evolution at a range of scales. This short communication describes the use of scale-dependent topographic anisotropy to characterize the structure of Santa Rosa Island in northwest Florida. Scale-dependent topographic relief and asymmetry were assessed from a LiDAR-derived DEM from May 2004, a few months before the island experienced widespread erosion and overwash during Hurricane Ivan. This application demonstrates how anisotropy can be used to identify unique scale-dependent structures that can be used to interpret the evolution of this barrier island. Results of this preliminary study further highlight the potential of using topographic anisotropy to controls on barrier island response and recovery to storms as well as island resiliency with sea level rise and storm activity.

  17. Barrier breakdown mechanism in nano-scale perpendicular magnetic tunnel junctions with ultrathin MgO barrier

    Science.gov (United States)

    Lv, Hua; Leitao, Diana C.; Hou, Zhiwei; Freitas, Paulo P.; Cardoso, Susana; Kämpfe, Thomas; Müller, Johannes; Langer, Juergen; Wrona, Jerzy

    2018-05-01

    Recently, the perpendicular magnetic tunnel junctions (p-MTJs) arouse great interest because of its unique features in the application of spin-transfer-torque magnetoresistive random access memory (STT-MRAM), such as low switching current density, good thermal stability and high access speed. In this paper, we investigated current induced switching (CIS) in ultrathin MgO barrier p-MTJs with dimension down to 50 nm. We obtained a CIS perpendicular tunnel magnetoresistance (p-TMR) of 123.9% and 7.0 Ω.μm2 resistance area product (RA) with a critical switching density of 1.4×1010 A/m2 in a 300 nm diameter junction. We observe that the extrinsic breakdown mechanism dominates, since the resistance of our p-MTJs decreases gradually with the increasing current. From the statistical analysis of differently sized p-MTJs, we observe that the breakdown voltage (Vb) of 1.4 V is 2 times the switching voltage (Vs) of 0.7 V and the breakdown process exhibits two different breakdown states, unsteady and steady state. Using Simmons' model, we find that the steady state is related with the barrier height of the MgO layer. Furthermore, our study suggests a more efficient method to evaluate the MTJ stability under high bias rather than measuring Vb. In conclusion, we developed well performant p-MTJs for the use in STT-MRAM and demonstrate the mechanism and control of breakdown in nano-scale ultrathin MgO barrier p-MTJs.

  18. Small scale monitoring of a bioremediation barrier using miniature electrical resistivity tomography

    Science.gov (United States)

    Sentenac, Philippe; Hogson, Tom; Keenan, Helen; Kulessa, Bernd

    2015-04-01

    The aim of this study was to assess, in the laboratory, the efficiency of a barrier of oxygen release compound (ORC) to block and divert a diesel plume migration in a scaled aquifer model using miniature electrical resistivity tomography (ERT) as the monitoring system. Two plumes of contaminant (diesel) were injected in a soil model made of local sand and clay. The diesel plumes migration was imaged and monitored using a miniature resistivity array system that has proved to be accurate in soil resistivity variations in small-scaled models of soil. ERT results reflected the lateral spreading and diversion of the diesel plumes in the unsaturated zone. One of the contaminant plumes was partially blocked by the ORC barrier and a diversion and reorganisation of the diesel in the soil matrix was observed. The technique of time-lapse ERT imaging showed that a dense non-aqueous phase liquid (DNAPL) contaminant like diesel can be monitored through a bioremediation barrier and the technique is well suited to monitor the efficiency of the barrier. Therefore, miniature ERT as a small-scale modelling tool could complement conventional techniques, which require more expensive and intrusive site investigation prior to remediation.

  19. PILOT-SCALE EVALUATION OF ENGINEERED BARRIER SYSTEMS FOR THE YUCCA MOUNTAIN PROJECT

    International Nuclear Information System (INIS)

    Webb, S.W.; George, J.T.; Finley, R.E.

    2001-01-01

    This paper describes two quarter-scale experiments (1.4 m diameter) and associated numerical analyses on granular backfill engineered barrier systems in support of the Yucca Mountain Project for the potential repository. The two configurations include a sloped capillary barrier and a plain backfill. The tests involve application of dyed water as a constant line infiltration source along the top of the test set-up, monitoring water movement through the test, and measuring water exiting the experiments. A complete water balance estimate is made for each test, and observed water movement is compared with (1) detailed numerical analyses conducted using the TOUGH2 code for unsaturated flow in porous media and (2) posttest observations. The results of the testing and analyses show that for the injection rates and configuration applied, the capillary barrier design diverts a significant amount of all injected water and the TOUGH2 pretest predictions show qualitative and quantitative agreement with the experimental data

  20. Motivators and barriers of a Healthy Lifestyle Scale: development and psychometric characteristics.

    Science.gov (United States)

    Downes, Loureen

    2008-01-01

    Black individuals suffer disproportionately from diseases that are preventable by lifestyle choices. The purpose of this study was to test the internal consistency and construct validity of the newly devised instrument, Motivators and Barriers of a Healthy Lifestyle Scale (MABS). The MABS was administered to 109 community-dwelling, adult Blacks. Content validity was supported through review of the literature and the judgment of three content experts. Exploratory factor analysis supported the two dimensions, that is, motivators and barriers. The Cronbach's alphas for the motivators and barriers dimensions were .88 and .90, respectively. Results provide initial evidence that the MABS is a valid, internally consistent measure of factors that motivate or inhibit healthy lifestyle behaviors. Screening with the MABS could encourage more focused health promotion discussions between patients and practitioners.

  1. Discursive barriers and cross-scale forest governance in Central Kalimantan, Indonesia

    Directory of Open Access Journals (Sweden)

    Caleb T. Gallemore

    2014-06-01

    Full Text Available Students of social-ecological systems have emphasized the need for effective cross-scale governance. We theorized that discursive barriers, particularly between technical and traditional practices, can act as a barrier to cross-scale collaboration. We analyzed the effects of discursive divides on collaboration on Reducing Emissions from Deforestation and Forest Degradation (REDD+ policy development in Central Kalimantan, an Indonesian province on the island of Borneo selected in 2010 to pilot subnational REDD+ policy. We argue that the complexities of bridging local land management practices and technical approaches to greenhouse gas emissions reduction and carbon offsetting create barriers to cross-scale collaboration. We tested these hypotheses using an exponential random graph model of collaboration among 36 organizations active in REDD+ policy in the province. We found that discursive divides were associated with a decreased probability of collaboration between organizations and that organizations headquartered outside the province were less likely to collaborate with organizations headquartered in the province. We conclude that bridging discursive communities presents a chicken-and-egg problem for cross-scale governance of social-ecological systems. In precisely the situations where it is most important, when bridging transnational standards with local knowledge and land management practices, it is the most difficult.

  2. Psychometric properties of the Exercise Benefits/Barriers Scale in Mexican elderly women

    Directory of Open Access Journals (Sweden)

    María Cristina Enríquez-Reyna

    Full Text Available ABSTRACT Objective: analyze and assess the psychometric properties of the subscales in the Spanish version of the Exercise Benefits/Barriers Scale in an elderly population in the Northeast of Mexico. Method: methodological study. The sample consisted of 329 elderly associated with one of the five public centers for senior citizens in the metropolitan area of Northeast Mexico. The psychometric properties included the assessment of the Cronbach's alpha coefficient, the Kaiser Meyer Olkin coefficient, the inter-item correlation, exploratory and confirmatory factor analysis. Results: in the principal components analysis, two components were identified based on the 43 items in the scale. The item-total correlation coefficient of the exercise benefits subscale was good. Nevertheless, the coefficient for the exercise barriers subscale revealed inconsistencies. The reliability and validity were acceptable. The confirmatory factor analysis revealed that the elimination of items improved the goodness of fit of the baseline scale, without affecting its validity or reliability. Conclusion: the Exercise Benefits/Barriers subscale presented satisfactory psychometric properties for the Mexican context. A 15-item short version is presented with factorial structure, validity and reliability similar to the complete scale.

  3. Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric oscillators.

    Science.gov (United States)

    Chan, H B; Stambaugh, C

    2007-08-10

    We explore fluctuation-induced switching in parametrically driven micromechanical torsional oscillators. The oscillators possess one, two, or three stable attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.

  4. Current Barriers to Large-scale Interoperability of Traceability Technology in the Seafood Sector.

    Science.gov (United States)

    Hardt, Marah J; Flett, Keith; Howell, Colleen J

    2017-08-01

    Interoperability is a critical component of full-chain digital traceability, but is almost nonexistent in the seafood industry. Using both quantitative and qualitative methodology, this study explores the barriers impeding progress toward large-scale interoperability among digital traceability systems in the seafood sector from the perspectives of seafood companies, technology vendors, and supply chains as a whole. We highlight lessons from recent research and field work focused on implementing traceability across full supply chains and make some recommendations for next steps in terms of overcoming challenges and scaling current efforts. © 2017 Institute of Food Technologists®.

  5. From coastal barriers to mountain belts - commonalities in fundamental geomorphic scaling laws

    Science.gov (United States)

    Lazarus, E.

    2016-12-01

    Overwash is a sediment-transport process essential to the form and resilience of coastal barrier landscapes. Driven by storm events, overwash leaves behind distinctive sedimentary features that, although intensively studied, have lacked unifying quantitative descriptions with which to compare their morphological attributes across documented examples or relate them to other morphodynamic phenomena. Geomorphic scaling laws quantify how measures of shape and size change with respect to another - information that helps to constrain predictions of future change and reconstructions of past environmental conditions. Here, a physical model of erosional and depositional overwash morphology yields intrinsic, allometric scaling laws involving length, width, area, volume, and alongshore spacing. Corroborative comparisons with natural washover morphology indicate scale invariance spanning several orders of magnitude. Several observers of the physical model remarked that the overwashed barrier resembled a dissected linear mountain front with an alluvial apron - an intriguing reimagining of the intended analog. Indeed, that resemblance is reflected quantitatively in these new scaling relationships, which align with canonical scaling laws for terrestrial and marine drainage basins and alluvial fans on Earth and Mars. This finding suggests disparate geomorphic systems that share common allometric properties may be related dynamically, perhaps by an influence more fundamental than characteristic erosion and deposition processes. Such an influence could come from emergent behavior at the intersection of advection and diffusion. Geomorphic behaviors at advection-diffusion transitions (and vice versa), specifically, could be the key to disentangling mechanistic causality from acausality in physical landscape patterns.

  6. Measuring parent time scarcity and fatigue as barriers to meal planning and preparation: quantitative scale development.

    Science.gov (United States)

    Storfer-Isser, Amy; Musher-Eizenman, Dara

    2013-03-01

    To examine the psychometric properties of 9 quantitative items that assess time scarcity and fatigue as parent barriers to planning and preparing meals for their children. A convenience sample of 342 parents of children aged 2-6 years completed a 20-minute online survey. Exploratory factor analysis was used to examine the factor structure and create summary scales. Internal consistency reliability and measures of construct and concurrent validity were assessed. Two scales were created based on the factor analysis: time and energy for meals and meal planning. Preliminary evidence suggests that both scales are reliable and valid. The time and energy for meals and meal planning scales can be completed quickly by busy and tired parents. As many children do not eat nutritious diets, a better understanding of the barriers that parents face is critical and may help inform interventions tailored to the needs of tired, busy parents. Copyright © 2013 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  7. Drivers and barriers to e-invoicing adoption in Greek large scale manufacturing industries

    Energy Technology Data Exchange (ETDEWEB)

    Marinagi, Catherine, E-mail: marinagi@teihal.gr, E-mail: ptrivel@yahoo.com, E-mail: preklitis@yahoo.com; Trivellas, Panagiotis, E-mail: marinagi@teihal.gr, E-mail: ptrivel@yahoo.com, E-mail: preklitis@yahoo.com; Reklitis, Panagiotis, E-mail: marinagi@teihal.gr, E-mail: ptrivel@yahoo.com, E-mail: preklitis@yahoo.com [Technological Educational Institute of Sterea Ellada, Department of Logistics management, 1st km of Old National Road Thiva-Elefsis-32200, Thiva (Greece); Skourlas, Christos, E-mail: cskourlas@teiath.gr [Technological Educational Institute of Athens, Department of Informatics, Ag. Spyridonos, Aigaleo-12210, Athens (Greece)

    2015-02-09

    This paper attempts to investigate the drivers and barriers that large-scale Greek manufacturing industries experience in adopting electronic invoices (e-invoices), based on three case studies with organizations having international presence in many countries. The study focuses on the drivers that may affect the increase of the adoption and use of e-invoicing, including the customers demand for e-invoices, and sufficient know-how and adoption of e-invoicing in organizations. In addition, the study reveals important barriers that prevent the expansion of e-invoicing, such as suppliers’ reluctance to implement e-invoicing, and IT infrastructures incompatibilities. Other issues examined by this study include the observed benefits from e-invoicing implementation, and the financial priorities of the organizations assumed to be supported by e-invoicing.

  8. Drivers and barriers to e-invoicing adoption in Greek large scale manufacturing industries

    International Nuclear Information System (INIS)

    Marinagi, Catherine; Trivellas, Panagiotis; Reklitis, Panagiotis; Skourlas, Christos

    2015-01-01

    This paper attempts to investigate the drivers and barriers that large-scale Greek manufacturing industries experience in adopting electronic invoices (e-invoices), based on three case studies with organizations having international presence in many countries. The study focuses on the drivers that may affect the increase of the adoption and use of e-invoicing, including the customers demand for e-invoices, and sufficient know-how and adoption of e-invoicing in organizations. In addition, the study reveals important barriers that prevent the expansion of e-invoicing, such as suppliers’ reluctance to implement e-invoicing, and IT infrastructures incompatibilities. Other issues examined by this study include the observed benefits from e-invoicing implementation, and the financial priorities of the organizations assumed to be supported by e-invoicing

  9. Biomass Gasification - A synthesis of technical barriers and current research issues for deployment at large scale

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, Stefan [Chalmers Univ. of Technology, Gothenburg (Sweden); Liliedahl, Truls [KTH, Royal Inst. of Technology, Stockholm (Sweden); Marklund, Magnus [Energy Technology Centre, Piteaa (Sweden)

    2013-09-01

    Thermal gasification at large scale for cogeneration of power and heat and/or production of fuels and materials is a main pathway for a sustainable deployment of biomass resources. However, so far no such full scale production exists and biomass gasification projects remain at the pilot or demonstration scale. This report focuses on the key critical technology challenges for the large-scale deployment of the following biomass-based gasification concepts: Direct Fluidized Bed Gasification (FBG), Entrained Flow Gasification (EFG) and indirect Dual Fluidized Bed Gasification (DFBG). The main content in this report is based on responses from a number of experts in biomass gasification obtained from a questionnaire. The survey was composed of a number of more or less specific questions on technical barriers as to the three gasification concepts considered. For formalising the questionnaire, the concept of Technology Readiness Level (TRL 1-9) was used for grading the level of technical maturity of the different sub-processes within the three generic biomass gasification technologies. For direct fluidized bed gasification (FBG) it is mentioned that the technology is already available at commercial scale as air-blown technology and thus that air-blown FBG gasification may be reckoned a mature technology. The remaining technical challenge is the conversion to operation on oxygen with the final goal of producing chemicals or transport fuels. Tar reduction, in particular, and gas cleaning and upgrading in general are by far the most frequently named technical issues considered problematic. Other important aspects are problems that may occur when operating on low-grade fuels - i.e. low-cost fuels. These problems include bed agglomeration/ash sintering as well as alkali fouling. Even the preparation and feeding of these low-grade fuels tend to be problematic and require further development to be used on a commercial scale. Furthermore, efficient char conversion is mentioned by

  10. Condensation on superhydrophobic surfaces: the role of local energy barriers and structure length scale.

    Science.gov (United States)

    Enright, Ryan; Miljkovic, Nenad; Al-Obeidi, Ahmed; Thompson, Carl V; Wang, Evelyn N

    2012-10-09

    Water condensation on surfaces is a ubiquitous phase-change process that plays a crucial role in nature and across a range of industrial applications, including energy production, desalination, and environmental control. Nanotechnology has created opportunities to manipulate this process through the precise control of surface structure and chemistry, thus enabling the biomimicry of natural surfaces, such as the leaves of certain plant species, to realize superhydrophobic condensation. However, this "bottom-up" wetting process is inadequately described using typical global thermodynamic analyses and remains poorly understood. In this work, we elucidate, through imaging experiments on surfaces with structure length scales ranging from 100 nm to 10 μm and wetting physics, how local energy barriers are essential to understand non-equilibrium condensed droplet morphologies and demonstrate that overcoming these barriers via nucleation-mediated droplet-droplet interactions leads to the emergence of wetting states not predicted by scale-invariant global thermodynamic analysis. This mechanistic understanding offers insight into the role of surface-structure length scale, provides a quantitative basis for designing surfaces optimized for condensation in engineered systems, and promises insight into ice formation on surfaces that initiates with the condensation of subcooled water.

  11. [Construction and validation of a short scale of perception of barriers for the physical activity in adolescents].

    Science.gov (United States)

    Cabanas-Sánchez, Verónica; Tejero-González, Carlos M; Veiga, Oscar L

    2012-01-01

    One of the main problems of health in the first world is the increase of physical inactivity. In this respect, adolescence has been identified as a critic period with high decline of physical activity. Therefore, a relevant line of research is the understanding of this social phenomenon. The aim of this study was to design a scale to assess perceived barriers to physical activity on adolescents. A convenience sample of 160 Spanish adolescents (84 girls), between 12 and 18 years old, was recruited for this study. Firstly, there were designed 40 items whose pertinence was evaluated through content validation by experts. Later, the participants were divided in two randomized groups, and Exploratory Factor Analysis and Confirmatory Factor Analysis were performed to define a short scale of 12 items. Cronbach Alfa Coefficent was used to evaluate internal consistence of the instrument. The scale reports four dimensions: incompatibility barriers (2 items), self-concept barriers (4 items), amotivation barriers (4 items) and social barriers (2 items). The scale showed enough construct validity (χ2=60.78; d.f.=48; p=0.100; GFI=0.88; CFI=0.94; RMSEA=0.58) and high internal reliability (α=0.80). Moreover, the scale was able to explain 67% of the data variance. The Short Scale of Perceived Barriers to Physical Activity in Adolescents is a valid and reliable instrument.

  12. Recent developments in large-scale ozone generation with dielectric barrier discharges

    Science.gov (United States)

    Lopez, Jose L.

    2014-10-01

    Large-scale ozone generation for industrial applications has been entirely based on the creation of microplasmas or microdischarges created using dielectric barrier discharge (DBD) reactors. Although versions of DBD generated ozone have been in continuous use for over a hundred years especially in water treatment, recent changes in environmental awareness and sustainability have lead to a surge of ozone generating facilities throughout the world. As a result of this enhanced global usage of this environmental cleaning application various new discoveries have emerged in the science and technology of ozone generation. This presentation will describe some of the most recent breakthrough developments in large-scale ozone generation while further addressing some of the current scientific and engineering challenges of this technology.

  13. Summary report on close-coupled subsurface barrier technology: Initial field trials to full-scale demonstration

    International Nuclear Information System (INIS)

    Heiser, J.H.

    1997-09-01

    The primary objective of this project was to develop and demonstrate the installation and measure the performance of a close-coupled barrier for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional, low-cost, cement-grout containment barrier followed by a thin lining of a polymer grout. The resultant barrier is a cement-polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. The technology has matured from a regulatory investigation of the issues concerning the use of polymers to laboratory compatibility and performance measurements of various polymer systems to a pilot-scale, single column injection at Sandia to full-scale demonstration. The feasibility of the close-coupled barrier concept was proven in a full-scale cold demonstration at Hanford, Washington and then moved to the final stage with a full-scale demonstration at an actual remediation site at Brookhaven National Laboratory (BNL). At the Hanford demonstration the composite barrier was emplaced around and beneath a 20,000 liter tank. The secondary cement layer was constructed using conventional jet grouting techniques. Drilling was completed at a 45 degree angle to the ground, forming a cone-shaped barrier. The primary barrier was placed by panel jet-grouting with a dual-wall drill stem using a two part polymer grout. The polymer chosen was a high molecular weight acrylic. At the BNL demonstration a V-trough barrier was installed using a conventional cement grout for the secondary layer and an acrylic-gel polymer for the primary layer. Construction techniques were identical to the Hanford installation. This report summarizes the technology development from pilot- to full-scale demonstrations and presents some of the performance and quality achievements attained

  14. Emotional Benefits and Barriers of Psychological Services Scale: Initial construction and validation among African American women.

    Science.gov (United States)

    Watson-Singleton, Natalie N; Okunoren, Oladoyin; LoParo, Devon; Hunter, Carla D

    2017-11-01

    The current study used the Health Belief Model to develop a measure that assessed the emotional benefits and barriers of professional psychological services in an African American women sample. Data from 251 African American women recruited from online organizations from across the United States (n = 164) and a Midwestern university psychology subject pool (n = 87) were used for exploratory factor analysis. Results revealed a 2-factor structure of the Emotional Benefits and Barriers of Psychological Services (EBBPS) Scale: Life Enhancement and Concerns about Distress, respectively. Confirmatory factor analysis was performed with data from 208 African American women who were recruited from a Midwestern university psychology subject pool (n = 81), Mturk (n = 104), and online organizations across the United States (n = 23). Results confirmed the EFA 2-factor model and demonstrated superior fit compared with a unidimensional model as well as a 3 factor model. Both factors exhibited excellent internal consistency. Construct validity was supported given that EBBPS factors were correlated with theoretically related constructs, like psychological help-seeking attitudes, intentions to seek counseling, and cultural identity, as well as uncorrelated with theoretically unrelated constructs, like psychological distress. These findings support the utility and cultural relevance of the EBBPS with African American women. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Preliminary Reliability and Validity of an Exercise Benefits and Barriers for Stroke Prevention Scale in an African American Sample.

    Science.gov (United States)

    Aycock, Dawn M; Clark, Patricia C

    2015-01-01

    African Americans are at heightened risk of first stroke, and regular exercise can reduce stroke risk. Benefits and barriers to exercise subscales from 2 instruments were combined to create the Exercise Benefits and Barriers for Stroke Prevention (EBBSP) scale. Reliability and validity of the EBBSP scale were examined in a nonrandom sample of 66 African Americans who were primarily female, average age 43.3 ± 9.4 years, and high school graduates. Both subscales had adequate internal consistency reliability. Factor analysis revealed two factors for each subscale. More benefits and fewer perceived barriers were significantly related to current exercise and future intentions to exercise. The EBBSP scale may be useful in research focused on understanding, predicting, and promoting exercise for stroke prevention in adults.

  16. Psychometric Properties of the Barriers to Treatment Participation Scale-Expectancies

    NARCIS (Netherlands)

    Nanninga, Marieke; Jansen, Danielle E. M. C.; Kazdin, Alan E.; Knorth, Erik J.; Reijneveld, Sijmen A.

    Expectations concerning barriers to children's psychosocial care seem to be major drivers when seeking help, but validated questionnaires measuring expectations are not available. Therefore, this study examined the psychometric properties of the parent and adolescent versions of the Barriers to

  17. Creation and validation of the barriers to alcohol reduction (BAR) scale using classical test theory and item response theory.

    Science.gov (United States)

    Kunicki, Zachary J; Schick, Melissa R; Spillane, Nichea S; Harlow, Lisa L

    2018-06-01

    Those who binge drink are at increased risk for alcohol-related consequences when compared to non-binge drinkers. Research shows individuals may face barriers to reducing their drinking behavior, but few measures exist to assess these barriers. This study created and validated the Barriers to Alcohol Reduction (BAR) scale. Participants were college students ( n  = 230) who endorsed at least one instance of past-month binge drinking (4+ drinks for women or 5+ drinks for men). Using classical test theory, exploratory structural equation modeling found a two-factor structure of personal/psychosocial barriers and perceived program barriers. The sub-factors, and full scale had reasonable internal consistency (i.e., coefficient omega = 0.78 (personal/psychosocial), 0.82 (program barriers), and 0.83 (full measure)). The BAR also showed evidence for convergent validity with the Brief Young Adult Alcohol Consequences Questionnaire ( r  = 0.39, p  Theory (IRT) analysis showed the two factors separately met the unidimensionality assumption, and provided further evidence for severity of the items on the two factors. Results suggest that the BAR measure appears reliable and valid for use in an undergraduate student population of binge drinkers. Future studies may want to re-examine this measure in a more diverse sample.

  18. Enablers and Barriers to Large-Scale Uptake of Improved Solid Fuel Stoves: A Systematic Review

    Science.gov (United States)

    Puzzolo, Elisa; Stanistreet, Debbi; Pope, Daniel; Bruce, Nigel G.

    2013-01-01

    NG. 2014. Enablers and barriers to large-scale uptake of improved solid fuel stoves: a systematic review. Environ Health Perspect 122:120–130; http://dx.doi.org/10.1289/ehp.1306639 PMID:24300100

  19. Fabricating a multi-level barrier-integrated microfluidic device using grey-scale photolithography

    International Nuclear Information System (INIS)

    Nam, Yoonkwang; Kim, Minseok; Kim, Taesung

    2013-01-01

    Most polymer-replica-based microfluidic devices are mainly fabricated by using standard soft-lithography technology so that multi-level masters (MLMs) require multiple spin-coatings, mask alignments, exposures, developments, and bakings. In this paper, we describe a simple method for fabricating MLMs for planar microfluidic channels with multi-level barriers (MLBs). A single photomask is necessary for standard photolithography technology to create a polydimethylsiloxane grey-scale photomask (PGSP), which adjusts the total amount of UV absorption in a negative-tone photoresist via a wide range of dye concentrations. Since the PGSP in turn adjusts the degree of cross-linking of the photoresist, this method enables the fabrication of MLMs for an MLB-integrated microfluidic device. Since the PGSP-based soft-lithography technology provides a simple but powerful fabrication method for MLBs in a microfluidic device, we believe that the fabrication method can be widely used for micro total analysis systems that benefit from MLBs. We demonstrate an MLB-integrated microfluidic device that can separate microparticles. (paper)

  20. Atomic oxygen production scaling in a nanosecond-pulsed externally grounded dielectric barrier plasma jet

    Science.gov (United States)

    Sands, Brian; Schmidt, Jacob; Ganguly, Biswa; Scofield, James

    2014-10-01

    Atomic oxygen production is studied in a capillary dielectric barrier plasma jet that is externally grounded and driven with a 20-ns risetime positive unipolar pulsed voltage at pulse repetition rates up to 25 kHz. The power coupled to the discharge can be easily increased by increasing the pulse repetition rate. At a critical turnover frequency, determined by the net energy density coupled to the discharge, the plasma chemistry abruptly changes. This is indicated by increased plasma conductance and a transition in reactive oxygen species production from an ozone-dominated production regime below the turnover frequency to atomic-oxygen-dominated production at higher pulse rates. Here, we characterize atomic oxygen production scaling using spatially- and temporally-resolved two-photon absorption laser-induced-fluorescence (TALIF). Quantitative results are obtained via calibration with xenon using a similar laser excitation and collection system. These results are compared with quantitative ozone and discharge power measurements using a helium gas flow with oxygen admixtures up to 3%.

  1. Psychometric properties of the Exercise Benefits/Barriers Scale in Mexican elderly women.

    Science.gov (United States)

    Enríquez-Reyna, María Cristina; Cruz-Castruita, Rosa María; Ceballos-Gurrola, Oswaldo; García-Cadena, Cirilo Humberto; Hernández-Cortés, Perla Lizeth; Guevara-Valtier, Milton Carlos

    2017-06-05

    analyze and assess the psychometric properties of the subscales in the Spanish version of the Exercise Benefits/Barriers Scale in an elderly population in the Northeast of Mexico. methodological study. The sample consisted of 329 elderly associated with one of the five public centers for senior citizens in the metropolitan area of Northeast Mexico. The psychometric properties included the assessment of the Cronbach's alpha coefficient, the Kaiser Meyer Olkin coefficient, the inter-item correlation, exploratory and confirmatory factor analysis. in the principal components analysis, two components were identified based on the 43 items in the scale. The item-total correlation coefficient of the exercise benefits subscale was good. Nevertheless, the coefficient for the exercise barriers subscale revealed inconsistencies. The reliability and validity were acceptable. The confirmatory factor analysis revealed that the elimination of items improved the goodness of fit of the baseline scale, without affecting its validity or reliability. the Exercise Benefits/Barriers subscale presented satisfactory psychometric properties for the Mexican context. A 15-item short version is presented with factorial structure, validity and reliability similar to the complete scale. analisar e avaliar as propriedades psicométricas das subescalas que compõem a versão em espanhol da Escala de Benefícios/Barreiras para o Exercício em uma população idosa do nordeste do México. estudo metodológico. A amostra abrangeu 329 idosas adstritas a uma das cinco casas de convivência públicas da área metropolitana do Nordeste mexicano. As propriedades psicométricas incluíram a avaliação do coeficiente alfa de Cronbach, o coeficiente Kaiser-Meyer-Olkin, a correlação inter-itens, análise fatorial exploratória e confirmatória. na análise de componentes principais, foram identificados dois componentes a partir dos 43 itens da escala. O coeficiente de correlação item-total da subescala

  2. Scale-dependent behavior of the foredune: Implications for barrier island response to storms and sea-level rise

    Science.gov (United States)

    Houser, Chris; Wernette, Phil; Weymer, Bradley A.

    2018-02-01

    The impact of storm surge on a barrier island tends to be considered from a single cross-shore dimension, dependent on the relative elevations of the storm surge and dune crest. However, the foredune is rarely uniform and can exhibit considerable variation in height and width at a range of length scales. In this study, LiDAR data from barrier islands in Texas and Florida are used to explore how shoreline position and dune morphology vary alongshore, and to determine how this variability is altered or reinforced by storms and post-storm recovery. Wavelet analysis reveals that a power law can approximate historical shoreline change across all scales, but that storm-scale shoreline change ( 10 years) and dune height exhibit similar scale-dependent variations at swash and surf zone scales (< 1000 m). The in-phase nature of the relationship between dune height and storm-scale shoreline change indicates that areas of greater storm-scale shoreline retreat are associated with areas of smaller dunes. It is argued that the decoupling of storm-scale and historical shoreline change at swash and surf zone scales is also associated with the alongshore redistribution of sediment and the tendency of shorelines to evolve to a more diffusive (or straight) pattern with time. The wavelet analysis of the data for post-storm dune recovery is also characterized by red noise at the smallest scales characteristic of diffusive systems, suggesting that it is possible that small-scale variations in dune height can be repaired through alongshore recovery and expansion if there is sufficient time between storms. However, the time required for dune recovery exceeds the time between storms capable of eroding and overwashing the dune. Correlation between historical shoreline retreat and the variance of the dune at swash and surf zone scales suggests that the persistence of the dune is an important control on transgression through island migration or shoreline retreat with relative sea-level rise.

  3. Understanding barriers to commercial-scale carbon capture and sequestration in the United States: An empirical assessment

    International Nuclear Information System (INIS)

    Davies, Lincoln L.; Uchitel, Kirsten; Ruple, John

    2013-01-01

    Although a potentially useful climate change mitigation tool, carbon capture and sequestration (CCS) efforts in the United States remain mired in demonstration and development. Prior studies suggest numerous reasons for this stagnation. This article empirically assesses those claims. Using an anonymous opinion survey completed by 229 CCS experts, we identified four primary barriers to CCS commercialization: (1) cost and cost recovery, (2) lack of a price signal or financial incentive, (3) long-term liability risks, and (4) lack of a comprehensive regulatory regime. These results give empirical weight to previous studies suggesting that CCS cost (and cost recovery) and liability risks are primary barriers to the technology. However, the need for comprehensive rather than piecemeal CCS regulation represents an emerging concern not previously singled out in the literature. Our results clearly show that the CCS community sees fragmented regulation as one of the most significant barriers to CCS deployment. Specifically, industry is united in its preference for a federal regulatory floor that is subject to state-level administration and sensitive to local conditions. Likewise, CCS experts share broad confidence in the technology's readiness, despite continued calls for commercial-scale demonstration projects before CCS is widely deployed. - Highlights: • We developed and distributed a unique CCS opinion survey. • Our analysis confirmed cost and liability as primary barriers to CCS deployment. • We identified regulatory barriers to CCS not previously singled out in the literature. • We address the need for comprehensive rather than piecemeal CCS regulation

  4. Translation, Cross-cultural Adaptation and Psychometric Validation of the Korean-Language Cardiac Rehabilitation Barriers Scale (CRBS-K).

    Science.gov (United States)

    Baek, Sora; Park, Hee-Won; Lee, Yookyung; Grace, Sherry L; Kim, Won-Seok

    2017-10-01

    To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (pKorea.

  5. Keeping the ‘Great’ in the Great Barrier Reef: large-scale governance of the Great Barrier Reef Marine Park

    Directory of Open Access Journals (Sweden)

    Louisa S. Evans

    2014-08-01

    Full Text Available As part of an international collaboration to compare large-scale commons, we used the Social-Ecological Systems Meta-Analysis Database (SESMAD to systematically map out attributes of and changes in the Great Barrier Reef Marine Park (GBRMP in Australia. We focus on eight design principles from common-pool resource (CPR theory and other key social-ecological systems governance variables, and explore to what extent they help explain the social and ecological outcomes of park management through time. Our analysis showed that commercial fisheries management and the re-zoning of the GBRMP in 2004 led to improvements in ecological condition of the reef, particularly fisheries. These boundary and rights changes were supported by effective monitoring, sanctioning and conflict resolution. Moderate biophysical connectivity was also important for improved outcomes. However, our analysis also highlighted that continued challenges to improved ecological health in terms of coral cover and biodiversity can be explained by fuzzy boundaries between land and sea, and the significance of external drivers to even large-scale social-ecological systems (SES. While ecological and institutional fit in the marine SES was high, this was not the case when considering the coastal SES. Nested governance arrangements become even more important at this larger scale. To our knowledge, our paper provides the first analysis linking the re-zoning of the GBRMP to CPR and SES theory. We discuss important challenges to coding large-scale systems for meta-analysis.

  6. Development of a continuous motorcycle protection barrier system using computer simulation and full-scale crash testing.

    Science.gov (United States)

    Atahan, Ali O; Hiekmann, J Marten; Himpe, Jeffrey; Marra, Joseph

    2018-07-01

    Road restraint systems are designed to minimize the undesirable effects of roadside accidents and improve safety of road users. These systems are utilized at either side or median section of roads to contain and redirect errant vehicles. Although restraint systems are mainly designed against car, truck and bus impacts there is an increasing pressure by the motorcycle industry to incorporate motorcycle protection systems into these systems. In this paper development details of a new and versatile motorcycle barrier, CMPS, coupled with an existing vehicle barrier is presented. CMPS is intended to safely contain and redirect motorcyclists during a collision event. First, crash performance of CMPS design is evaluated by means of a three dimensional computer simulation program LS-DYNA. Then full-scale crash tests are used to verify the acceptability of CMPS design. Crash tests were performed at CSI proving ground facility using a motorcycle dummy in accordance with prEN 1317-8 specification. Full-scale crash test results show that CMPS is able to successfully contain and redirect dummy with minimal injury risk on the dummy. Damage on the barrier is also minimal proving the robustness of the CMPS design. Based on the test findings and further review by the authorities the implementation of CMPS was recommended at highway system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Adolescents' Self-Efficacy to Overcome Barriers to Physical Activity Scale

    Science.gov (United States)

    Dwyer, John J. M.; Chulak, Tala; Maitland, Scott; Allison, Kenneth R.; Lysy, Daria C.; Faulkner, Guy E. J.; Sheeshka, Judy

    2012-01-01

    This paper describes a revised measure of self-efficacy to overcome barriers to moderate and vigorous physical activity in a sample of 484 high school students in Toronto, Ontario. The students had a mean age of 15.3 years. Principal axis factoring with oblique rotation yielded five factors: self-efficacy to overcome internal, harassment, physical…

  8. Barriers to Investment in Utility-scale Variable Renewable Electricity (VRE) Projects

    NARCIS (Netherlands)

    Hu, J.; Harmsen, R.; Crijns-Graus, W.; Worrell, E.

    To effectively mitigate climate change, variable renewable electricity (VRE) is expected to substitute a great share of current fossil-fired electricity generation. However, VRE investments can be obstructed by many barriers, endangering the amount of investments needed in order to be consistent

  9. Trade Barrier Elimination, Economics of Scale and Market Competition: Computable General Equilibrium Model

    Directory of Open Access Journals (Sweden)

    Widyastutik Widyastutik

    2017-07-01

    Full Text Available The ASEAN and its dialogue partner countries agreed to reduce trade barriers in the services sector, one of which is sea transport services. The purpose of this study is to estimate the equivalent tax of non-tariff barriers in the sea transport services. Besides that, this study is going to analyze the economic impacts of the regulatory barriers elimination in the sea transport services of ASEAN and its dialogue partner countries. Using the gravity model, it can be identified that trade barriers of sea transport services sector of ASEAN and dialogue partner countries are still relatively high. Additionally, by adopting IC-IRTS model in Global CGE Model (GTAP, the simulation results show consistent results with the theory of pro-competitive effects. The greater gain from trade is obtained in the CGE model assuming IC-IRTS compared to PC-CRTS. China gains a greater benefit that is indicated by the highest increase in welfare and GDP followed by Japan and AustraliaDOI: 10.15408/sjie.v6i2.5279

  10. Theoretical and Spectroscopic investigations of conformations, rotational barriers and scaled vibrations of 2,3-dimethyl hexane

    Directory of Open Access Journals (Sweden)

    Aziz Aboulmouhajir

    2017-01-01

    Full Text Available The 2,3-dimethyl hexane conformational isomerism has been investigated in detail, based on HF, Post-HF and DFT calculations at different basis set. The effect of size of basis, ZPE, thermal contributions, electronic correlation and optimization methods on the conformational stability was discussed. The rotational barriers from the most stable conformer to the lowest energy secondary conformers and their correspondent inversion barriers at both HF and MP2 methods using 6-31G* basis set have also been approached. A normal mode calculation of the most and less-stable conformers using a scaled ab initio force field in terms of non-redundant local symmetry coordinates have been made to elucidate the conformational dependence of the vibrational spectra.

  11. Inferring coastal processes from regional-scale mapping of 222Radon and salinity: examples from the Great Barrier Reef, Australia

    International Nuclear Information System (INIS)

    Stieglitz, Thomas C.; Cook, Peter G.; Burnett, William C.

    2010-01-01

    The radon isotope 222 Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes.

  12. Small-scale barriers mitigate desertification processes and enhance plant recruitment in a degraded semiarid grassland

    Science.gov (United States)

    Fick, Stephen E; Decker, Cheryl E.; Duniway, Michael C.; Miller, Mark E.

    2016-01-01

    Anthropogenic desertification is a problem that plagues drylands globally; however, the factors which maintain degraded states are often unclear. In Canyonlands National Park on the Colorado Plateau of southeastern Utah, many degraded grasslands have not recovered structure and function >40 yr after release from livestock grazing pressure, necessitating active restoration. We hypothesized that multiple factors contribute to the persistent degraded state, including lack of seed availability, surficial soil-hydrological properties, and high levels of spatial connectivity (lack of perennial vegetation and other surface structure to retain water, litter, seed, and sediment). In combination with seeding and surface raking treatments, we tested the effect of small barrier structures (“ConMods”) designed to disrupt the loss of litter, seed and sediment in degraded soil patches within the park. Grass establishment was highest when all treatments (structures, seed addition, and soil disturbance) were combined, but only in the second year after installation, following favorable climatic conditions. We suggest that multiple limiting factors were ameliorated by treatments, including seed limitation and microsite availability, seed removal by harvester ants, and stressful abiotic conditions. Higher densities of grass seedlings on the north and east sides of barrier structures following the summer months suggest that structures may have functioned as artificial “nurse-plants”, sheltering seedlings from wind and radiation as well as accumulating wind-blown resources. Barrier structures increased the establishment of both native perennial grasses and exotic annuals, although there were species-specific differences in mortality related to spatial distribution of seedlings within barrier structures. The unique success of all treatments combined, and even then only under favorable climatic conditions and in certain soil patches, highlights that restoration success (and

  13. Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

    Science.gov (United States)

    Kassem, Hachem; Thompson, Charlotte E. L.; Amos, Carl L.; Townend, Ian H.

    2015-10-01

    The suspension of sediments by oscillatory flows is a complex case of fluid-particle interaction. The aim of this study is to provide insight into the spatial (time) and scale (frequency) relationships between wave-generated boundary layer turbulence and event-driven sediment transport beneath irregular shoaling and breaking waves in the nearshore of a prototype sandy barrier beach, using data collected through the Barrier Dynamics Experiment II (BARDEX II). Statistical, quadrant and spectral analyses reveal the anisotropic and intermittent nature of Reynolds' stresses (momentum exchange) in the wave boundary layer, in all three orthogonal planes of motion. The fractional contribution of coherent turbulence structures appears to be dictated by the structural form of eddies beneath plunging and spilling breakers, which in turn define the net sediment mobilisation towards or away from the barrier, and hence ensuing erosion and accretion trends. A standing transverse wave is also observed in the flume, contributing to the substantial skewness of spanwise turbulence. Observed low frequency suspensions are closely linked to the mean flow (wave) properties. Wavelet analysis reveals that the entrainment and maintenance of sediment in suspension through a cluster of bursting sequence is associated with the passage of intermittent slowly-evolving large structures, which can modulate the frequency of smaller motions. Outside the boundary layer, small scale, higher frequency turbulence drives the suspension. The extent to which these spatially varied perturbation clusters persist is associated with suspension events in the high frequency scales, decaying as the turbulent motion ceases to supply momentum, with an observed hysteresis effect.

  14. Fragmentation reduces regional-scale spatial genetic structure in a wind-pollinated tree because genetic barriers are removed.

    Science.gov (United States)

    Wang, Rong; Compton, Stephen G; Shi, Yi-Su; Chen, Xiao-Yong

    2012-09-01

    Gene flow strongly influences the regional genetic structuring of plant populations. Seed and pollen dispersal patterns can respond differently to the increased isolation resulting from habitat fragmentation, with unpredictable consequences for gene flow and population structuring. In a recently fragmented landscape we compared the pre- and post-fragmentation genetic structure of populations of a tree species where pollen and seed dispersal respond differentially to forest fragmentation generated by flooding. Castanopsis sclerophylla is wind-pollinated, with seeds that are dispersed by gravity and rodents. Using microsatellites, we found no significant difference in genetic diversity between pre- and post-fragmentation cohorts. Significant genetic structure was observed in pre-fragmentation cohorts, due to an unknown genetic barrier that had isolated one small population. Among post-fragmentation cohorts this genetic barrier had disappeared and genetic structure was significantly weakened. The strengths of genetic structuring were at a similar level in both cohorts, suggesting that overall gene flow of C. sclerophylla has been unchanged by fragmentation at the regional scale. Fragmentation has blocked seed dispersal among habitats, but this appears to have been compensated for by enhanced pollen dispersal, as indicated by the disappearance of a genetic barrier, probably as a result of increased wind speeds and easier pollen movement over water. Extensive pollen flow can counteract some negative effects of fragmentation and assist the long-term persistence of small remnant populations.

  15. Setting Learning Analytics in Context: Overcoming the Barriers to Large-Scale Adoption

    Science.gov (United States)

    Ferguson, Rebecca; Macfadyen, Leah P.; Clow, Doug; Tynan, Belinda; Alexander, Shirley; Dawson, Shane

    2014-01-01

    A core goal for most learning analytic projects is to move from small-scale research towards broader institutional implementation, but this introduces a new set of challenges because institutions are stable systems, resistant to change. To avoid failure and maximize success, implementation of learning analytics at scale requires explicit and…

  16. Large-scale bleaching of corals on the Great Barrier Reef.

    Science.gov (United States)

    Hughes, T P; Kerry, J T; Simpson, T

    2018-02-01

    In 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching. In the southern hemisphere summer of March-April 2016, we used aerial surveys to measure the level of bleaching on 1,156 individual reefs throughout the 2,300 km length of the Great Barrier Reef, the world's largest coral reef system. The accuracy of the aerial scores was ground-truthed with detailed underwater surveys of bleaching at 260 sites (104 reefs), allowing us to compare aerial and underwater bleaching data with satellite-derived temperatures and with associated model predictions of bleaching. The severity of bleaching on individual reefs in 2016 was tightly correlated with the level of local heat exposure: the southernmost region of the Great Barrier Reef escaped with only minor bleaching because summer temperatures there were close to average. Gradients in nutrients and turbidity from inshore to offshore across the Great Barrier Reef had minimal effect on the severity of bleaching. Similarly, bleaching was equally severe on reefs that are open or closed to fishing, once the level of satellite-derived heat exposure was accounted for. The level of post-bleaching mortality, measured underwater after 7-8 months, was tightly correlated with the aerial scores measured at the peak of bleaching. Similarly, reefs with a high aerial bleaching score also experienced major shifts in species composition due to extensive mortality of heat-sensitive species. Reefs with low bleaching scores did not change in composition, and some showed minor increases in coral cover. Two earlier mass bleaching events occurred on the Great Barrier Reef in 1998 and 2002, that were less severe than 2016. In 2016, bleaching, compared to 42% in 2002 and 44% in 1998. Conversely, the proportion of reefs that were severely bleached (>60% of corals affected) was four times higher in 2016. The geographic footprint of each of the three events is distinctive, and matches satellite-derived sea surface

  17. The A14-scale: development and evaluation of a questionnaire for assessment of adherence and individual barriers.

    Science.gov (United States)

    Jank, Susanne; Bertsche, Thilo; Schellberg, Dieter; Herzog, Wolfgang; Haefeli, Walter E

    2009-08-01

    To develop a questionnaire ("A14") for the description of adherence and individual barriers as basis for adherence-enhancing interventions in the clinical and pharmaceutical setting, and to compare it to the validated German MMAS (Morisky Medication Adherence Scale). Fourteen questions with a 5-item likert-scale from "never" (4) to "very often" (0) were given to 150 medical inpatients. According to their score, patients were classified into non-adherent (score <50) or adherent (score 50-56). On the dichotomous MMAS, "yes" is scored 0 and "no" 1 point, a total score of 4 indicating adherence. Patients with complete scales were compared with the remaining patients regarding socio-demographic factors. Descriptive statistics, Cronbach's Alpha, Spearman correlation, and kappa were computed. Eighty-three participants completed both scales. Patients with missing values differed significantly regarding age, education, and adherence according to MMAS. Cronbach's Alpha for A14 was 0.861. MMAS and A14 median total scores were 4 and 52, respectively. About 39.5% of patients were non-adherent as per MMAS compared to 40% as per A14; kappa was 0.262 (P = 0.016). The total scores correlated with a Rho-value of 0.43 (P < 0.001). The A14-scale showed good internal consistency and a significant correlation with the MMAS suggesting that it merits further investigation.

  18. Small scale model and underground laboratory study of engineered barrier thermal behaviour

    International Nuclear Information System (INIS)

    Dardaine, M.; Beziat, A.; Gatabin, C.; Lefevre, I.; Plas, F.; Fontan, N.; Moyne, C.

    1991-01-01

    This is the final report of the contract CCE FI1W/0061, which had the objective of studying the thermal behaviour of the engineered barrier having the selected French clay Fo-Ca (natural calcic smectite) as its major constituent. After being installed this barrier was subjected simultaneously to the heat flux dissipated by the container and to a possible rehydration by contact with the host medium. It consists of three parts. The first part is devoted to R and D studies concerning detectors suitable for the point measurement of the water concentration. Among the techniques that can be envisaged, capacitor methods, which are very temperature sensitive, would require a great deal of effort to be satisfactory. On the other hand, the water concentration can, in principle, be derived from the measurement of the thermal conductivity in the transient regime. Although the carrying out of this measurement is somewhat critical, it can give good results under certain conditions. The second part reports experiments carried out in the laboratory concerning both the study of heat transfer during the so-called dry phase of the disposal (without any water being supplied externally) and the study of the phenomenon of fissuration. Finally, the third part describes the in situ experiment BACCHUS, carried out in the underground test facility at Mol (Belgium), in collaboration with the CEN/SCK. In the course of the five months of the thermal phase of this experiment a large variation in the amplitude of the temperature gradients was recorded, which may be explained, on one hand, by the convergence of the medium and, on the other hand, by a much more rapid rehydration than that predicted

  19. Permeable reactive barriers for the remediation of groundwater in a mining area: results for a pilot-scale project

    Science.gov (United States)

    Martinez-Sanchez, Maria Jose; Perez-Sirvent, Carmen; Garcia-Lorenzo, Maria Luz; Martinez-Lopez, Salvadora; Perez-Espinosa, Victor; Gonzalez-Ciudad, Eva; Belen Martinez-Martinez, Lucia; Hernandez, Carmen; Molina-Ruiz, Jose

    2017-04-01

    The Sierra Minera of Cartagena-La Union is located in the Region of Murcia, Southeast of Spain. This zone presents high levels of heavy metals due to natural, geogenic reasons. In addition, the prolonged mining activity, and subsequent abandonment of farms, has had consequences on the environment, including severe affectation of the groundwater in the area. To remediate this situation, the Permeable Reactive Barrier (PRB) technology was assayed, which required in addition to the hydro-geological study of the zone, a careful optimization study for the design and construction of PRBs. For such a purpose a pilot-scale project was developed, and this communication reports some of the most relevant findings obtained after a four-years monitorization period. The selected reactive material for the PRBs was limestone filler. The filler is a waste material produced in many factories in the zone. These residues have good adsorption properties, high alkalinity, low cost and high availability, which make them suitable for use in remediation. The PRB was constituted by a 50% limestone filler and 50% sand, a proportion optimized by means of independent batch experiments. A layer of gravel was placed at the top, and on it a layer of natural soil. The barrier was designed in the form of a continuous trench, because the level of the contaminated groundwater was not very deep. In this way, the barrier could be prepared with standard excavation equipment. Parallel to the barrier, 6 wells where arranged downstream for sample collection. The pH and conductivity of the samples was measured directly in situ, and the content of Zn, Cd, Cu, Fe, and Pb were analyzed in the laboratory. All the samples collected after the PRB was constructed had basic pH values between 7.5 and 8. The conductivity was between 5 and 11 mS / cm except for the well 4, which had a value of 3.70 mS / cm. The concentration values of trace elements were below the detection limit (atomic absorption measurement) in

  20. Barriers to innovation in small-scale industries: case study from the briquetting industry in India

    NARCIS (Netherlands)

    Clancy, Joy S.

    2001-01-01

    This paper focuses on the innovation process in small- and medium-scale industries in developing countries, raking the briquetting (densification of biomass) as a case study. The technical efficiency was found to vary significantly between firms, which can be attributed to the lack of technological

  1. Full-scale test on coupled thermo-hydro-mechanical processes in engineered barrier system

    International Nuclear Information System (INIS)

    Moro, Yoshiji; Fujita, Tomoo; Kanno, Takeshi; Kobayashi, Akira.

    1994-01-01

    On dynamic behavior within artificial barrier in ground layer disposal of high level radioactive wastes, some phenomena such as exotherm from the wastes, penetration of groundwater from surrounding base rock, swelling pressure formation of buffer material due to penetration of groundwater, ground pressure change of the surrounding base rock, and so forth are supposed to affect each other. It is one of important problems from a viewpoint of elucidation of near field environment in the property evaluation study to evaluate such thermo-hydro-mechanical coupled phenomena. As results of the investigation from such reason and its application to actual test in accompany with execution of heating and water inserting test in the Big-Ben (Big-Bentonite facility), the following informations were obtained: (1) In heating and water inserting test, data on temperature distribution, water content ratio distribution and swelling pressure of each portion for 5 months could be obtained. (2) water migration due to water slope was divided to migrations due to steam and liquid water, of which models were made according to Fick and Darcy laws, respectively. (3) As a simulation of water migration, water diffusion coefficient due to temperature slope could be expressed almost by a model with nonlinearity to temperature. (G.K.)

  2. FEBEX: Full-Scale engineered barriers experiment in crystalline host-rock: preoperational phase. Synthesized report

    International Nuclear Information System (INIS)

    1997-01-01

    The FEBEX project is being cofinanced by the EC under contract F 14WCT950006. In addition to the EC, seven partners from three countries of the EU. (France, Germany, and Spain) as well as one from EFTA (Switzerland) are participating in the project. ENRESA is the coordinating partner with NAGRA assisting in coordinating some aspects. The project consists of two large-scale tests and a series of complimentary laboratory tests. The work is being executed by the following organizations: CIEMAT, AITEMIN, UP-DIT (CIMNE), ULC, CSIC-Zaidin, and UPM (SPAIN) ANDRA and G.3S (FRANCE) GRS (GERMANY). This report includes a synthesized description of the experiment from its conception through the installation of the two large-scale tests (from the middle of 1994 to the beginning of 1997, preoperation stage). The experiment is described in detail in a series of specific reports. (Author)

  3. Mind the gap! Barriers and implementation deficiencies of energy policies at the local scale in urban China

    International Nuclear Information System (INIS)

    Wu, Jing; Zuidema, Christian; Gugerell, Katharina; Roo, Gert de

    2017-01-01

    Environmental concerns and potential social-economic impacts associated with fossil fuels have turned cities into indispensable entities for supporting energy transitions in China. Pursuing a transition towards a sustainable energy system has become a major policy concern for the Chinese central government. In response, and on the basis of a top-down and conformance-oriented system of policy implementation and evaluation, the Chinese central government has launched various policies and targets on energy efficiency and production that lower levels of government have to follow. However, the translation of top-down targets and the measurement of conformance-based targets have both proved to be problematic. This paper investigates Chinese state policy on energy efficiency through four empirical case studies. It identifies how policy design of target setting and evaluation is both impacting and driving the implementation of energy efficiency at the local urban scale. We demonstrate how local authorities are faced with constraining barriers that can inhibit the implementation of centrally issued targets and policies. These barriers may even undermine local performance in the pursuit of ambitious energy efficiency goals, resulting in potentially harmful consequences. - Highlights: • Energy efficiency policies are ill-adapted to the diversity of local circumstances. • Predominant focus on conformance in energy policies overlooks local performance. • Pursuing ambitions runs the risk of being undermined by strict measuring systems. • Chinese energy transition needs more flexibility in target setting and evaluation.

  4. A large-scale laboratory investigation into the movement of gas and water through clay barriers exposed to the environment

    International Nuclear Information System (INIS)

    1993-01-01

    This report describes a large scale laboratory investigation into the movements of gas and water through clay barriers exposed to the environment. The test beds, each 3m square were constructed and filled with clay to a depth of 400 mm, after compaction. One test bed contained London Clay, the other Glacial Till. The clays were subjected to accelerated environmental cycling and tests carried out on samples of the clays at appropriate intervals. The tests included measurements of the mechanical, physical and chemical properties of the clays and their permeability to gas and water. Gas permeability emerged as the more appropriate for the clays being investigated. The report discusses the difficulties of measuring the permeability of partially saturated clays and the need to define the measuring techniques when specifying limiting acceptability values. 55 refs., 8 figs., 7 tabs., 27 plates

  5. Distributed small-scale wind in New Zealand: Advantages, barriers and policy support instruments

    International Nuclear Information System (INIS)

    Barry, Martin; Chapman, Ralph

    2009-01-01

    If future climate change goals being negotiated internationally are to have any chance of being achieved, developed countries need to undertake a major transition in their energy systems. This will require a rapid expansion of renewable energy generation, including wind electricity. Wind energy in New Zealand is commercially viable in many cases, yet opportunities for its exploitation are far from fully utilised. Many communities are showing resistance to wind farm developments, since large wind farms are often seen as intrusive. Building wind farms on a small scale may be a useful way of overcoming this problem. This study examines the pattern of recent wind industry development in New Zealand. It is argued that two key characteristics have emerged that are limiting the potential development of the industry: a trend towards large scale, leading to increased local opposition; and a small number of investors. Research methods include a review of international and local literature, and a rural mail survey questionnaire, with 338 respondents. We provide survey evidence that small wind farms, and community ownership of them, may be attractive to local communities, and that this point of advantage is helpful for the rapid expansion of wind generation in New Zealand.

  6. Controlled fabrication of nano-scale double barrier magnetic tunnel junctions using focused ion beam milling method

    International Nuclear Information System (INIS)

    Wei, H.X.; Wang, T.X.; Zeng, Z.M.; Zhang, X.Q.; Zhao, J.; Han, X.F.

    2006-01-01

    The controlled fabrication method for nano-scale double barrier magnetic tunnel junctions (DBMTJs) with the layer structure of Ta(5)/Cu(10)/Ni 79 Fe 21 (5)/Ir 22 Mn 78 (12)/Co 6 Fe 2 B 2 (4)/Al(1) -oxide/Co 6 Fe 2 B 2 (6)/Al (1)-oxide/Co 6 Fe 2 B 2 (4)/Ir 22 Mn 78 (12)/Ni 79 Fe 21 (5)/Ta(5) (thickness unit: nm) was used. This method involved depositing thin multi-layer stacks by sputtering system, and depositing a Pt nano-pillar using a focused ion beam which acted both as a top contact and as an etching mask. The advantages of this process over the traditional process using e-beam and optical lithography in that it involve only few processing steps, e.g. it does not involve any lift-off steps. In order to evaluate the nanofabrication techniques, the DBMTJs with the dimensions of 200 nmx400 nm, 200 nmx200 nm nano-scale were prepared and their R-H, I-V characteristics were measured.

  7. Target detection and localization in shallow water: an experimental demonstration of the acoustic barrier problem at the laboratory scale.

    Science.gov (United States)

    Marandet, Christian; Roux, Philippe; Nicolas, Barbara; Mars, Jérôme

    2011-01-01

    This study demonstrates experimentally at the laboratory scale the detection and localization of a wavelength-sized target in a shallow ultrasonic waveguide between two source-receiver arrays at 3 MHz. In the framework of the acoustic barrier problem, at the 1/1000 scale, the waveguide represents a 1.1-km-long, 52-m-deep ocean acoustic channel in the kilohertz frequency range. The two coplanar arrays record in the time-domain the transfer matrix of the waveguide between each pair of source-receiver transducers. Invoking the reciprocity principle, a time-domain double-beamforming algorithm is simultaneously performed on the source and receiver arrays. This array processing projects the multireverberated acoustic echoes into an equivalent set of eigenrays, which are defined by their launch and arrival angles. Comparison is made between the intensity of each eigenray without and with a target for detection in the waveguide. Localization is performed through tomography inversion of the acoustic impedance of the target, using all of the eigenrays extracted from double beamforming. The use of the diffraction-based sensitivity kernel for each eigenray provides both the localization and the signature of the target. Experimental results are shown in the presence of surface waves, and methodological issues are discussed for detection and localization.

  8. Barriers to renewable energy development: A case study of large-scale wind energy in Saskatchewan, Canada

    International Nuclear Information System (INIS)

    Richards, Garrett; Noble, Bram; Belcher, Ken

    2012-01-01

    Renewable energy is receiving increased attention as a viable alternative to non-renewable electrical generation, however, meeting global energy demands will require a more ambitious renewable energy program than is currently the case. There have been several reviews of potential technological, economic, social, or public barriers and solutions to renewable energy investment. Although important, there is also need for multi-dimensional analyses of these barriers and identification of the most significant underlying barriers if viable solutions are to be developed. In this paper we apply a theoretical framework to examine stakeholder's perceptions and understanding of the barriers to wind energy development in Saskatchewan, Canada. We identify and examine the most significant underlying barriers to investment in renewable energy and the interactions between those barriers. Results show a number of perceived barriers to wind energy investment, however, these barriers can be explained in large part by knowledge barriers, if not disagreement over whether the current level of investment in wind energy is sufficient. We show that barriers to renewable energy cannot be explained solely by technological, social, political, or economic factors in isolation, and that a multi-dimensional approach, identifying and explaining the underlying sources of these barriers, is necessary to develop viable solutions. - Highlights: ► Meeting future wind energy objectives requires an ambitious investment program. ► A framework is applied to identify and explain perceived barriers to wind energy. ► Stakeholders perceived technological and political barriers as the most significant. ► These could be explained by knowledge barriers and complacency with the status quo. ► Even with additional investment these underlying barriers will constrain progress.

  9. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.

    2016-11-15

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  10. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.; Harrison, Hugo B.; Almany, Glenn R.; Berumen, Michael L.; Bode, Michael; Bonin, Mary C.; Choukroun, Severine; Doherty, Peter J.; Frisch, Ashley J.; Saenz-Agudelo, Pablo; Jones, Geoffrey P.

    2016-01-01

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  11. Observation of scaling laws of ion confining potential versus thermal barrier depth and of axial particle confinement time in the tandem mirror GAMMA 10

    International Nuclear Information System (INIS)

    Cho, T.; Inutake, M.; Ishii, K.

    1988-01-01

    In the thermal barrier tandem mirror GAMMA 10, the scaling law governing the enhancement of the ion confining potential, φ c , resulting from thermal barrier formation, is obtained experimentally, and is consistently interpreted in terms of the weak and strong ECH theories set up by Cohen and co-workers. The scaling law on the axial particle confinement time, τ pparallel , related to this φ c formation, is also demonstrated in detail; it is in good agreement with the Pastukhov theory as modified by Cohen and co-workers. This scaling is verified at any radial position in the core plasma region and at any time through the various stages of a discharge; this indicates a scaling with drastic improvement of τ pparallel , due to the potential formation in the tandem mirror plasma. (author). 41 refs, 12 figs

  12. The solar noise barrier project 3. The effects of seasonal spectral variation, cloud cover and heat distribution on the performance of full-scale luminescent solar concentrator panels

    NARCIS (Netherlands)

    Debije, M.G.; Tzikas, C.; de Jong, M.; Kanellis, M.; Slooff, L.H.

    We report on the relative performances of two large-scale luminescent solar concentrator (LSC) noise barriers placed in an outdoor environment monitored for over a year. Comparisons are made for the performances of a number of attached photovoltaic cells with changing spectral illumination, cloud

  13. Regional-scale variation in the distribution and abundance of farming damselfishes on Australia's Great Barrier Reef

    KAUST Repository

    Emslie, Michael J.

    2012-03-15

    Territorial damselfishes that manipulate ("farm") the algae in their territories can have a marked effect on benthic community structure and may influence coral recovery following disturbances. Despite the numerical dominance of farming species on many reefs, the importance of their grazing activities is often overlooked, with most studies only examining their roles over restricted spatial and temporal scales. We used the results of field surveys covering 9.5° of latitude of the Great Barrier Reef to describe the distribution, abundance and temporal dynamics of farmer communities. Redundancy analysis revealed unique subregional assemblages of farming species that were shaped by the combined effects of shelf position and, to a lesser extent, by latitude. These spatial patterns were largely stable through time, except when major disturbances altered the benthic community. Such disturbances affected the functional guilds of farmers in different ways. Since different guilds of farmers modify benthic community structure and affect survival of juvenile corals in different ways, these results have important implications for coral recovery following disturbances. © 2012 Springer-Verlag.

  14. Regional-scale variation in the distribution and abundance of farming damselfishes on Australia's Great Barrier Reef

    KAUST Repository

    Emslie, Michael J.; Logan, Murray; Ceccarelli, Daniela M.; Cheal, Alistair J.; Hoey, Andrew; Miller, Ian R.; Sweatman, Hugh P A

    2012-01-01

    Territorial damselfishes that manipulate ("farm") the algae in their territories can have a marked effect on benthic community structure and may influence coral recovery following disturbances. Despite the numerical dominance of farming species on many reefs, the importance of their grazing activities is often overlooked, with most studies only examining their roles over restricted spatial and temporal scales. We used the results of field surveys covering 9.5° of latitude of the Great Barrier Reef to describe the distribution, abundance and temporal dynamics of farmer communities. Redundancy analysis revealed unique subregional assemblages of farming species that were shaped by the combined effects of shelf position and, to a lesser extent, by latitude. These spatial patterns were largely stable through time, except when major disturbances altered the benthic community. Such disturbances affected the functional guilds of farmers in different ways. Since different guilds of farmers modify benthic community structure and affect survival of juvenile corals in different ways, these results have important implications for coral recovery following disturbances. © 2012 Springer-Verlag.

  15. Coastal Barrier Resource Areas, Barrier Islands and Spits; s44gbb89; Barrier Beaches as defined by RI CRMC were barrier beaches as defined by RI CRMC were identified on quad maps and manually digitized from tablets, Published in 1989, 1:24000 (1in=2000ft) scale, Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Coastal Barrier Resource Areas dataset current as of 1989. Barrier Islands and Spits; s44gbb89; Barrier Beaches as defined by RI CRMC were barrier beaches as defined...

  16. What are the barriers to scaling up health interventions in low and middle income countries? A qualitative study of academic leaders in implementation science

    Directory of Open Access Journals (Sweden)

    Yamey Gavin

    2012-05-01

    Full Text Available Abstract Background Most low and middle income countries (LMICs are currently not on track to reach the health-related Millennium Development Goals (MDGs. One way to accelerate progress would be through the large-scale implementation of evidence-based health tools and interventions. This study aimed to: (a explore the barriers that have impeded such scale-up in LMICs, and (b lay out an “implementation research agenda”—a series of key research questions that need to be addressed in order to help overcome such barriers. Methods Interviews were conducted with fourteen key informants, all of whom are academic leaders in the field of implementation science, who were purposively selected for their expertise in scaling up in LMICs. Interviews were transcribed by hand and manually coded to look for emerging themes related to the two study aims. Barriers to scaling up, and unanswered research questions, were organized into six categories, representing different components of the scaling up process: attributes of the intervention; attributes of the implementers; scale-up approach; attributes of the adopting community; socio-political, fiscal, and cultural context; and research context. Results Factors impeding the success of scale-up that emerged from the key informant interviews, and which are areas for future investigation, include: complexity of the intervention and lack of technical consensus; limited human resource, leadership, management, and health systems capacity; poor application of proven diffusion techniques; lack of engagement of local implementers and of the adopting community; and inadequate integration of research into scale-up efforts. Conclusions Key steps in expanding the evidence base on implementation in LMICs include studying how to: simplify interventions; train “scale-up leaders” and health workers dedicated to scale-up; reach and engage communities; match the best delivery strategy to the specific health problem and

  17. Analysis and experimental study on formation conditions of large-scale barrier-free diffuse atmospheric pressure air plasmas in repetitive pulse mode

    Science.gov (United States)

    Li, Lee; Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang

    2014-01-01

    Atmospheric air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse atmospheric plasmas in open air should meet the three conditions: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation conditions of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.

  18. Do clouds save the great barrier reef? satellite imagery elucidates the cloud-SST relationship at the local scale.

    Directory of Open Access Journals (Sweden)

    Susannah M Leahy

    Full Text Available Evidence of global climate change and rising sea surface temperatures (SSTs is now well documented in the scientific literature. With corals already living close to their thermal maxima, increases in SSTs are of great concern for the survival of coral reefs. Cloud feedback processes may have the potential to constrain SSTs, serving to enforce an "ocean thermostat" and promoting the survival of coral reefs. In this study, it was hypothesized that cloud cover can affect summer SSTs in the tropics. Detailed direct and lagged relationships between cloud cover and SST across the central Great Barrier Reef (GBR shelf were investigated using data from satellite imagery and in situ temperature and light loggers during two relatively hot summers (2005 and 2006 and two relatively cool summers (2007 and 2008. Across all study summers and shelf positions, SSTs exhibited distinct drops during periods of high cloud cover, and conversely, SST increases during periods of low cloud cover, with a three-day temporal lag between a change in cloud cover and a subsequent change in SST. Cloud cover alone was responsible for up to 32.1% of the variation in SSTs three days later. The relationship was strongest in both El Niño (2005 and La Niña (2008 study summers and at the inner-shelf position in those summers. SST effects on subsequent cloud cover were weaker and more variable among study summers, with rising SSTs explaining up to 21.6% of the increase in cloud cover three days later. This work quantifies the often observed cloud cooling effect on coral reefs. It highlights the importance of incorporating local-scale processes into bleaching forecasting models, and encourages the use of remote sensing imagery to value-add to coral bleaching field studies and to more accurately predict risks to coral reefs.

  19. Large-scale renewable energy project barriers: Environmental impact assessment streamlining efforts in Japan and the EU

    International Nuclear Information System (INIS)

    Schumacher, Kim

    2017-01-01

    Environmental Impact Assessment (EIA) procedures have been identified as a major barrier to renewable energy (RE) development with regards to large-scale projects (LS-RE). However EIA laws have also been neglected by many decision-makers who have been underestimating its impact on RE development and the stifling potential they possess. As a consequence, apart from acknowledging the shortcomings of the systems currently in place, few governments momentarily have concrete plans to reform their EIA laws. By looking at recent EIA streamlining efforts in two industrialized regions that underwent major transformations in their energy sectors, this paper attempts to assess how such reform efforts can act as a means to support the balancing of environmental protection and climate change mitigation with socio-economic challenges. Thereby this paper fills this intellectual void by identifying the strengths and weaknesses of the Japanese EIA law by contrasting it with the recently revised EIA Directive of the European Union (EU). This enables the identification of the regulatory provisions that impact RE development the most and the determination of how structured EIA law reforms would affect domestic RE project development. The main focus lies on the evaluation of regulatory streamlining efforts in the Japanese and EU contexts through the application of a mixed-methods approach, consisting of in-depth literary and legal reviews, followed by a comparative analysis and a series of semi-structured interviews. Highlighting several legal inconsistencies in combination with the views of EIA professionals, academics and law- and policymakers, allowed for a more comprehensive assessment of what streamlining elements of the reformed EU EIA Directive and the proposed Japanese EIA framework modifications could either promote or stifle further RE deployment. - Highlights: •Performs an in-depth review of EIA reforms in OECD territories •First paper to compare Japan and the European

  20. Best-worst scaling to assess the most important barriers and facilitators for the use of health technology assessment in Austria.

    Science.gov (United States)

    Feig, Chiara; Cheung, Kei Long; Hiligsmann, Mickaël; Evers, Silvia M A A; Simon, Judit; Mayer, Susanne

    2018-04-01

    Although Health Technology Assessment (HTA) is increasingly used to support evidence-based decision-making in health care, several barriers and facilitators for the use of HTA have been identified. This best-worst scaling (BWS) study aims to assess the relative importance of selected barriers and facilitators of the uptake of HTA studies in Austria. A BWS object case survey was conducted among 37 experts in Austria to assess the relative importance of HTA barriers and facilitators. Hierarchical Bayes estimation was applied, with the best-worst count analysis as sensitivity analysis. Subgroup analyses were also performed on professional role and HTA experience. The most important barriers were 'lack of transparency in the decision-making process', 'fragmentation', 'absence of appropriate incentives', 'no explicit framework for decision-making process', and 'insufficient legal support'. The most important facilitators were 'transparency in the decision-making process', 'availability of relevant HTA research for policy makers', 'availability of explicit framework for decision-making process', 'sufficient legal support', and 'appropriate incentives'. This study suggests that HTA barriers and facilitators related to the context of decision makers, especially 'policy characteristics' and 'organization and resources' are the most important in Austria. A transparent and participatory decision-making process could improve the adoption of HTA evidence.

  1. Analysis, scale modeling, and full-scale test of a railcar and spent-nuclear-fuel shipping cask in a high-velocity impact against a rigid barrier

    International Nuclear Information System (INIS)

    Huerta, M.

    1981-06-01

    This report describes the mathematical analysis, the physical scale modeling, and a full-scale crash test of a railcar spent-nuclear-fuel shipping system. The mathematical analysis utilized a lumped-parameter model to predict the structural response of the railcar and the shipping cask. The physical scale modeling analysis consisted of two crash tests that used 1/8-scale models to assess railcar and shipping cask damage. The full-scale crash test, conducted with retired railcar equipment, was carefully monitored with onboard instrumentation and high-speed photography. Results of the mathematical and scale modeling analyses are compared with the full-scale test. 29 figures

  2. Laboratory-scale column study for remediation of TCE-contaminated aquifers using three-section controlled-release potassium permanganate barriers.

    Science.gov (United States)

    Yuan, Baoling; Li, Fei; Chen, Yanmei; Fu, Ming-Lai

    2013-05-01

    A laboratory-scale study with a sand column was designed to simulate trichloroethylene (TCE) pollution in the aquifer environment with three-section controlled-release potassium permanganate (CRP) barriers. The main objective of this study was to evaluate the feasibility of CRP barriers in remediation of TCE in aquifers in a long-term and controlled manner. CRP particles with a 1:3 molar ratio of KMnO4 to stearic acid showed the best controlled-release properties in pure water, and the theoretical release time was 138.5 days. The results of TCE removal in the test column indicated that complete removal efficiency of TCE in a sand column by three-section CRP barriers could be reached within 15 days. The molar ratio of KMnO4 to TCE in the three-section CRP barriers was 16:1, which was much lower than 82:1 as required when KMnO4 solution is used directly to achieve complete destruction of TCE. This result revealed that the efficiency of CRP for remediation of TCE was highly improved after encapsulation.

  3. Inferring coastal processes from regional-scale mapping of {sup 222}Radon and salinity: examples from the Great Barrier Reef, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Stieglitz, Thomas C., E-mail: thomas.stieglitz@jcu.edu.a [AIMS-JCU, Townsville (Australia); Australian Institute of Marine Science, PMB NO 3, Townsville QLD 4810 (Australia); School of Engineering and Physical Sciences, James Cook University, Townsville QLD 4811 (Australia); Cook, Peter G., E-mail: peter.g.cook@csiro.a [CSIRO Land and Water, Private Bag 2, Glen Osmond SA 5064 (Australia); Burnett, William C., E-mail: wburnett@mailer.fsu.ed [Department of Oceanography, Florida State University, Tallahassee, FL 32306 (United States)

    2010-07-15

    The radon isotope {sup 222}Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes.

  4. Barrier Island Dynamics Using Mass Center Analysis: A New Way to Detect and Track Large-Scale Change

    Directory of Open Access Journals (Sweden)

    Paul Paris

    2014-01-01

    Full Text Available A geographic information system (GIS was used to introduce and test a new method for quantitatively characterizing topographic change. Borrowing from classic Newtonian mechanics, the concept of a body’s center of mass is applied to the geomorphic landscape, and the barrier island environment in particular, to evaluate the metric’s potential as a proxy for detecting, tracking and visualizing change. Two barrier islands along North Carolina’s Outer Banks are used to test this idea: Core Banks, uninhabited and largely-undeveloped, and Hatteras Island, altered by the presence of a protective dune system. Findings indicate that for Core Banks, the alongshore change in the center of mass is in accord with dominate littoral transport and wind conditions. Cross-shore change agrees with independent estimates for the island migration rates. This lends credence to our assertion that the mass center metric has the potential to be a viable proxy for describing wholesale barrier migration and would be a valuable addition to the already-established ocean shoreline and subaerial volume metrics. More research is, however, required to demonstrate efficacy.

  5. Observation of ion confining potential enhancement due to thermal barrier potential formation and its scaling law in the tandem mirror GAMMA 10

    International Nuclear Information System (INIS)

    Cho, Teruji; Nakashima, Yousuke; Foote, J.H.

    1987-01-01

    In the tandem mirror GAMMA 10, (i) the enhancement of the ion confining potential, φ c , only during the period of the thermal barrier potential φ b -formation, has been observed first by using not only end-loss-analysers (ELA's) of GAMMA 10 but an end-loss-ion-spectrometer (ELIS) installed from TMX-U. This results in strong end-loss-ion plugging with increased central cell density. (ii) The first experimental observation of the φ c vs φ b -scaling law is obtained, where φ c increases with φ b . This scaling law is consistently interpreted by Cohen's theories of the weak-ECH and the strong-ECH in the plug region. (iii) Good agreement of the plug potential measured with the ELA's and the ELIS is achieved. (author)

  6. Non-linear, non-monotonic effect of nano-scale roughness on particle deposition in absence of an energy barrier: Experiments and modeling

    Science.gov (United States)

    Jin, Chao; Glawdel, Tomasz; Ren, Carolyn L.; Emelko, Monica B.

    2015-12-01

    Deposition of colloidal- and nano-scale particles on surfaces is critical to numerous natural and engineered environmental, health, and industrial applications ranging from drinking water treatment to semi-conductor manufacturing. Nano-scale surface roughness-induced hydrodynamic impacts on particle deposition were evaluated in the absence of an energy barrier to deposition in a parallel plate system. A non-linear, non-monotonic relationship between deposition surface roughness and particle deposition flux was observed and a critical roughness size associated with minimum deposition flux or “sag effect” was identified. This effect was more significant for nanoparticles (<1 μm) than for colloids and was numerically simulated using a Convective-Diffusion model and experimentally validated. Inclusion of flow field and hydrodynamic retardation effects explained particle deposition profiles better than when only the Derjaguin-Landau-Verwey-Overbeek (DLVO) force was considered. This work provides 1) a first comprehensive framework for describing the hydrodynamic impacts of nano-scale surface roughness on particle deposition by unifying hydrodynamic forces (using the most current approaches for describing flow field profiles and hydrodynamic retardation effects) with appropriately modified expressions for DLVO interaction energies, and gravity forces in one model and 2) a foundation for further describing the impacts of more complicated scales of deposition surface roughness on particle deposition.

  7. Exploring barriers and enablers for scaling up a community-based grain bank intervention for improved infant and young child feeding in Ethiopia: A qualitative process evaluation.

    Science.gov (United States)

    Sako, Binta; Leerlooijer, Joanne N; Lelisa, Azeb; Hailemariam, Abebe; Brouwer, Inge D; Tucker Brown, Amal; Osendarp, Saskia J M

    2018-04-01

    Child malnutrition remains high in Ethiopia, and inadequate complementary feeding is a contributing factor. In this context, a community-based intervention was designed to provide locally made complementary food for children 6-23 months, using a bartering system, in four Ethiopian regions. After a pilot phase, the intervention was scaled up from 8 to 180 localities. We conducted a process evaluation to determine enablers and barriers for the scaling up of this intervention. Eight study sites were selected to perform 52 key informant interviews and 31 focus group discussions with purposely selected informants. For analysis, we used a framework describing six elements of successful scaling up: socio-political context, attributes of the intervention, attributes of the implementers, appropriate delivery strategy, the adopting community, and use of research to inform the scale-up process. A strong political will, alignment of the intervention with national priorities, and integration with the health care system were instrumental in the scaling up. The participatory approach in decision-making reinforced ownership at community level, and training about complementary feeding motivated mothers and women's groups to participate. However, the management of the complex intervention, limited human resources, and lack of incentives for female volunteers proved challenging. In the bartering model, the barter rate was accepted, but the bartering was hindered by unavailability of cereals and limited financial and material resources to contribute, threatening the project's sustainability. Scaling up strategies for nutrition interventions require sufficient time, thorough planning, and assessment of the community's capacity to contribute human, financial, and material resources. © 2017 The Authors. Maternal and Child Nutrition Published by John Wiley & Sons, Ltd.

  8. Glass Barriers : Constraints to Women's Small-Scale Cross-Border Trade in Cambodia and Lao PDR

    OpenAIRE

    Seror, Marlon; Record, Richard; Clarke, Julian

    2017-01-01

    Trade facilitation projects often assume indirect benefits for small-scale, cross-border traders. Recent studies have shown the challenges faced in Africa by this population, especially women, but it remains unknown in Cambodia and the Lao People's Democratic Republic, despite large trade facilitation investments. This paper fills this gap, thanks to an innovative mix of original qualitati...

  9. Drivers and barriers for municipal retrofitting activities – Evidence from a large-scale survey of German local authorities

    NARCIS (Netherlands)

    Polzin, Friedemann|info:eu-repo/dai/nl/413317404; Nolden, Colin; von Flotow, Paschen

    2018-01-01

    Local authorities are key actors for implementing innovative energy efficiency technologies (retrofitting) to reduce end-use energy demand and consequently reduce negative effects of high energy use such as climate change and public budget deficits. This paper reports the results of a large-scale

  10. Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Wang, Qingguo, E-mail: wqgyyy@126.com [College of Food Science and Engineering, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Xu, Jing, E-mail: jiaxu@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China)

    2016-11-15

    Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm{sup −1}) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

  11. Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

    International Nuclear Information System (INIS)

    Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

    2016-01-01

    Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm −1 ) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

  12. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  13. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock. Final report

    International Nuclear Information System (INIS)

    Alberdi, J.; Barcala, J. M.; Campos, R.; Cuevas, A. M.; Fernandez, E.

    2000-01-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  14. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock

    Energy Technology Data Exchange (ETDEWEB)

    Alberid, J; Barcala, J M; Campos, R; Cuevas, A M; Fernandez, E [Ciemat. Madrid (Spain)

    2000-07-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  15. Breaking Computational Barriers: Real-time Analysis and Optimization with Large-scale Nonlinear Models via Model Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Carlberg, Kevin Thomas [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Quantitative Modeling and Analysis; Drohmann, Martin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Quantitative Modeling and Analysis; Tuminaro, Raymond S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Computational Mathematics; Boggs, Paul T. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Quantitative Modeling and Analysis; Ray, Jaideep [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Quantitative Modeling and Analysis; van Bloemen Waanders, Bart Gustaaf [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Optimization and Uncertainty Estimation

    2014-10-01

    Model reduction for dynamical systems is a promising approach for reducing the computational cost of large-scale physics-based simulations to enable high-fidelity models to be used in many- query (e.g., Bayesian inference) and near-real-time (e.g., fast-turnaround simulation) contexts. While model reduction works well for specialized problems such as linear time-invariant systems, it is much more difficult to obtain accurate, stable, and efficient reduced-order models (ROMs) for systems with general nonlinearities. This report describes several advances that enable nonlinear reduced-order models (ROMs) to be deployed in a variety of time-critical settings. First, we present an error bound for the Gauss-Newton with Approximated Tensors (GNAT) nonlinear model reduction technique. This bound allows the state-space error for the GNAT method to be quantified when applied with the backward Euler time-integration scheme. Second, we present a methodology for preserving classical Lagrangian structure in nonlinear model reduction. This technique guarantees that important properties--such as energy conservation and symplectic time-evolution maps--are preserved when performing model reduction for models described by a Lagrangian formalism (e.g., molecular dynamics, structural dynamics). Third, we present a novel technique for decreasing the temporal complexity --defined as the number of Newton-like iterations performed over the course of the simulation--by exploiting time-domain data. Fourth, we describe a novel method for refining projection-based reduced-order models a posteriori using a goal-oriented framework similar to mesh-adaptive h -refinement in finite elements. The technique allows the ROM to generate arbitrarily accurate solutions, thereby providing the ROM with a 'failsafe' mechanism in the event of insufficient training data. Finally, we present the reduced-order model error surrogate (ROMES) method for statistically quantifying reduced- order

  16. FEBEX-DP. Dismantling the ''full-scale engineered barrier experiment'' after 18 years of operation at the Grimsel Test Site, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Kober, Florian; Gaus, Irina [Nagra, Wettingen (Switzerland)

    2015-07-01

    The FEBEX experiment at the Grimsel Test Site (GTS) consists of an in-situ full-scale engineered barrier system (EBS) test for the disposal of high-level waste (HLW). It is performed under natural conditions in crystalline rock in which the canisters are placed horizontally in drifts and are surrounded by a clay barrier constructed of highly compacted bentonite blocks. A partial dismantling and sampling of the EBS was carried out during 2002. Heating of the FEBEX started in 1997 and since then a constant temperature of 100 deg C has been maintained, while the bentonite buffer has been slowly hydrating in a natural way. A total of 632 sensors in the bentonite barrier, the rock mass, the heaters and the service zone record temperature, water saturation, humidity, total pressure, displacement, and water pressure. The hydration pattern is relatively symmetric, with no major differences along the axis. Although the host rock is characterized by heterogeneities with zones of higher permeability, the resaturation process is driven by the suction of the bentonite rather than by the availability of water in the rock, especially in the early phase. After 17 years, the water content in the buffer close to the heater still continues to increase slowly. The hydraulic pore pressures in the buffer and the geosphere have practically stabilized. The total pressure in general continues to increase in most points into the buffer, where in some parts pressures of over 6 MPa are registered. The long monitoring phase and the partial dismantling in 2002 indicate that the EBS has largely performed as expected and the major processes and couplings affecting the buffer saturation during the initial thermal period identified prior to the start of the experiment have been confirmed. A comprehensive report documents and reviews the state of the FEBEX (Lanyon and Gaus, 2013). After 18 years of operation the experiment will be excavated and dismantled in 2015. The main objectives of the FEBEX

  17. The solar noise barrier project : 2. The effect of street art on performance of a large scale luminescent solar concentrator prototype

    NARCIS (Netherlands)

    Debije, M.G.; Tzikas, C.; Rajkumar, V.A.; de Jong, M.

    2017-01-01

    Noise barriers have been used worldwide to reduce the impact of sound generated from traffic on nearby areas. A common feature to appear on these noise barriers are all manner of graffiti and street art. In this work we describe the relative performance of a large area luminescent solar concentrator

  18. CATSIUS CLAY PROJECT: Calculation and testing of behaviour of unsaturated clay as barrier in radioactive waste repositories: stage 3: validation exercises at a large in situ scale

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E E; Alcoverro, J

    1999-07-01

    Stage 3 of CATSIUS CLAY Project: Validation Exercises at a Large in situ Scale includes two Benchmarks: Benchmark 3.1: In situ Hydration of Boom Clay Pellets (BACCHUS 2) and Benchmark 3.2: FEBEX Mock-up Test. The BACCHUS 2 in situ test was performed in the HADES underground laboratory (Mol, Belgium) to demonstrate and optimize an installation procedure for a clay based material and to study its hydration process. After drilling a vertical shaft (540 mm in diameter, 3.0 m in length) in the host Boom clay, a central filter (90 mm in diameter) was placed, the remaining space was filled with a mixture of clay pellets and clay powder and the assembly was sealed at the upper end by a resin plug (0.20 m in thickness) over which concrete was poured. The test was instrumented so that it could be used as a validation experiment. Total stress, pore water pressure and water content measurements were performed both in the backfill material and in the surrounding clay massif. Once the installation was complete, the natural hydration of the backfill material began (day 0). To accelerate the hydration process, on day 516 water was injected through the central filter. On day 624, after the saturation of the backfill was reached, the hydraulic circuit was closed and the undrained response of the system backfill-host clay was monitored until an overall steady state was reached. Partners were asked to provide predictions for the evolution of the pore water pressure and total pressure of various points where appropriate sensors are installed. This benchmark addresses the Hydro-Mechanical response of an unsaturated low density clay barrier under natural and artificial hydration. (Author)

  19. CATSIUS CLAY PROJECT: Calculation and testing of behaviour of unsaturated clay as barrier in radioactive waste repositories: stage 3: validation exercises at a large in situ scale

    International Nuclear Information System (INIS)

    Alonso, E. E.; Alcoverro, J.

    1999-01-01

    Stage 3 of CATSIUS CLAY Project: Validation Exercises at a Large in situ Scale includes two Benchmarks: Benchmark 3.1: In situ Hydration of Boom Clay Pellets (BACCHUS 2) and Benchmark 3.2: FEBEX Mock-up Test. The BACCHUS 2 in situ test was performed in the HADES underground laboratory (Mol, Belgium) to demonstrate and optimize an installation procedure for a clay based material and to study its hydration process. After drilling a vertical shaft (540 mm in diameter, 3.0 m in length) in the host Boom clay, a central filter (90 mm in diameter) was placed, the remaining space was filled with a mixture of clay pellets and clay powder and the assembly was sealed at the upper end by a resin plug (0.20 m in thickness) over which concrete was poured. The test was instrumented so that it could be used as a validation experiment. Total stress, pore water pressure and water content measurements were performed both in the backfill material and in the surrounding clay massif. Once the installation was complete, the natural hydration of the backfill material began (day 0). To accelerate the hydration process, on day 516 water was injected through the central filter. On day 624, after the saturation of the backfill was reached, the hydraulic circuit was closed and the undrained response of the system backfill-host clay was monitored until an overall steady state was reached. Partners were asked to provide predictions for the evolution of the pore water pressure and total pressure of various points where appropriate sensors are installed. This benchmark addresses the Hydro-Mechanical response of an unsaturated low density clay barrier under natural and artificial hydration. (Author)

  20. Congruent biogeographical disjunctions at a continent-wide scale: Quantifying and clarifying the role of biogeographic barriers in the Australian tropics

    Science.gov (United States)

    Crisp, Michael D.; Cook, Dianne H.; Cook, Lyn G.

    2017-01-01

    Aim To test whether novel and previously hypothesized biogeogaphic barriers in the Australian Tropics represent significant disjunction points or hard barriers, or both, to the distribution of plants. Location Australian tropics: Australian Monsoon Tropics and Australian Wet Tropics. Methods The presence or absence of 6,861 plant species was scored across 13 putative biogeographic barriers in the Australian Tropics, including two that have not previously been recognised. Randomizations of these data were used to test whether more species showed disjunctions (gaps in distribution) or likely barriers (range limits) at these points than expected by chance. Results Two novel disjunctions in the Australian Tropics flora are identified in addition to eleven putative barriers previously recognized for animals. Of these, eleven disjunction points (all within the Australian Monsoon Tropics) were found to correspond to range-ending barriers to a significant number of species, while neither of the two disjunctions found within the Australian Wet Tropics limited a significant number of species’ ranges. Main conclusions Biogeographic barriers present significant distributional limits to native plant species in the Australian Monsoon Tropics but not in the Australian Wet Tropics. PMID:28376094

  1. Combined effect of capillary barrier and layered slope on water, solute and nanoparticle transfer in an unsaturated soil at lysimeter scale.

    Science.gov (United States)

    Prédélus, Dieuseul; Coutinho, Artur Paiva; Lassabatere, Laurent; Bien, Le Binh; Winiarski, Thierry; Angulo-Jaramillo, Rafael

    2015-10-01

    It is well recognized that colloidal nanoparticles are highly mobile in soils and can facilitate the transport of contaminants through the vadose zone. This work presents the combined effect of the capillary barrier and soil layer slope on the transport of water, bromide and nanoparticles through an unsaturated soil. Experiments were performed in a lysimeter (1×1×1.6m(3)) called LUGH (Lysimeter for Urban Groundwater Hydrology). The LUGH has 15 outputs that identify the temporal and spatial evolution of water flow, solute flux and nanoparticles in relation to the soil surface conditions and the 3D system configuration. Two different soil structures were set up in the lysimeter. The first structure comprises a layer of sand (0-0.2cm, in diameter) 35cm thick placed horizontally above a layer of bimodal mixture also 35cm thick to create a capillary barrier at the interface between the sand and bimodal material. The bimodal material is composed of a mixture 50% by weight of sand and gravel (0.4-1.1cm, in diameter). The second structure, using the same amount of sand and bimodal mixture as the first structure represents an interface with a 25% slope. A 3D numerical model based on Richards equation for flow and the convection dispersion equations coupled with a mechanical module for nanoparticle trapping was developed. The results showed that under the effect of the capillary barrier, water accumulated at the interface of the two materials. The sloped structure deflects flow in contrast to the structure with zero slope. Approximately 80% of nanoparticles are retained in the lysimeter, with a greater retention at the interface of two materials. Finally, the model makes a good reproduction of physical mechanisms observed and appears to be a useful tool for identifying key processes leading to a better understanding of the effect of capillary barrier on nanoparticle transfer in an unsaturated heterogeneous soil. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Barrier island facies models and recognition criteria

    Science.gov (United States)

    Mulhern, J.; Johnson, C. L.

    2017-12-01

    Barrier island outcrops record transgressive shoreline motion at geologic timescales, providing integral clues to understanding how coastlines respond to rising sea levels. However, barrier island deposits are difficult to recognize. While significant progress has been made in understanding the modern coastal morphodynamics, this insight is not fully leveraged in existing barrier island facies models. Excellent outcrop exposures of the paralic Upper Cretaceous Straight Cliffs Formation of southern Utah provide an opportunity to revise facies models and recognition criteria for barrier island deposits. Preserved barrier islands are composed of three main architectural elements (shorefaces, tidal inlets, and tidal channels) which occur independently or in combination to create larger-scale barrier island deposits. Barrier island shorefaces record progradation, while barrier island tidal inlets record lateral migration, and barrier island tidal channels record aggradation within the tidal inlet. Four facies associations are used to describe and characterize these barrier island architectural elements. Barrier islands occur in association with backarrier fill and internally contain lower and upper shoreface, high-energy upper shoreface, and tidal channel facies. Barrier islands bound lagoons or estuaries, and are distinguished from other shoreface deposits by their internal facies and geometry, association with backbarrier facies, and position within transgressive successions. Tidal processes, in particular tidal inlet migration and reworking of the upper shoreface, also distinguish barrier island deposits. Existing barrier island models highlight the short term heterogeneous and dynamic nature of barrier island systems, yet overlook processes tied to geologic time scales, such as multi-directional motion, erosion, and reworking, and their expressions in preserved barrier island strata. This study uses characteristic outcrop expressions of barrier island successions to

  3. Barrier Systems

    NARCIS (Netherlands)

    Heteren, S. van

    2015-01-01

    Barrier-system dynamics are a function of antecedent topography and substrate lithology, Relative sea-level (RSL) changes, sediment availability and type, climate, vegetation type and cover, and various aero- and hydrodynamic processes during fair-weather conditions and extreme events. Global change

  4. A large-scale electrophoresis- and chromatography-based determination of gene expression profiles in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties

    Directory of Open Access Journals (Sweden)

    Duban-Deweer Sophie

    2010-11-01

    Full Text Available Abstract Background Brain capillary endothelial cells (BCECs form the physiological basis of the blood-brain barrier (BBB. The barrier function is (at least in part due to well-known proteins such as transporters, tight junctions and metabolic barrier proteins (e.g. monoamine oxidase, gamma glutamyltranspeptidase and P-glycoprotein. Our previous 2-dimensional gel proteome analysis had identified a large number of proteins and revealed the major role of dynamic cytoskeletal remodelling in the differentiation of bovine BCECs. The aim of the present study was to elaborate a reference proteome of Triton X-100-soluble species from bovine BCECs cultured in the well-established in vitro BBB model developed in our laboratory. Results A total of 215 protein spots (corresponding to 130 distinct proteins were identified by 2-dimensional gel electrophoresis, whereas over 350 proteins were identified by a shotgun approach. We classified around 430 distinct proteins expressed by bovine BCECs. Our large-scale gene expression analysis enabled the correction of mistakes referenced into protein databases (e.g. bovine vinculin and constitutes valuable evidence for predictions based on genome annotation. Conclusions Elaboration of a reference proteome constitutes the first step in creating a gene expression database dedicated to capillary endothelial cells displaying BBB characteristics. It improves of our knowledge of the BBB and the key proteins in cell structures, cytoskeleton organization, metabolism, detoxification and drug resistance. Moreover, our results emphasize the need for both appropriate experimental design and correct interpretation of proteome datasets.

  5. Career Adapt-Abilities Scale--Italian Form: Psychometric Properties and Relationships to Breadth of Interests, Quality of Life, and Perceived Barriers

    Science.gov (United States)

    Soresi, Salvatore; Nota, Laura; Ferrari, Lea

    2012-01-01

    The Career Adapt-Abilities Scale (CAAS)-Italian Form consists of four 6-item scales, which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. The 24-item CAAS-Italian Form is identical to the International Form 2.0. The factor structure was…

  6. Information barriers

    International Nuclear Information System (INIS)

    Fuller, J.L.; Wolford, J.

    2001-01-01

    Full text: An information barrier (IB) consists of procedures and technology that prevent the release of sensitive information during a joint inspection of a sensitive nuclear item, and provides confidence that the measurement system into which it has been integrated functions exactly as designed and constructed. Work in the U.S. on radiation detection system information barriers dates back at least to 1990, even though the terminology is more recent. In January 1999 the Joint DoD-DOE Information Barrier Working Group was formed in the United States to help coordinate technical efforts related to information barrier R and D. This paper presents an overview of the efforts of this group, by its Chairs, as well as recommendations for further information barrier R and D. Progress on the demonstration of monitoring systems containing IBs is also provided. From the U.S. perspective, the basic, top-level functional requirements for the information barrier portion of an integrated radiation signature-information barrier inspection system are twofold: The host must be assured that his classified information is protected from disclosure to the inspecting party; and The inspecting party must be confident that the integrated inspection system measures, processes, and presents the radiation-signature-based measurement conclusion in an accurate and reproducible manner. It is the position of the United States that in the absence of any agreement to share classified nuclear weapons design information in the conduct of an inspection regime, the requirement to protect host country classified warhead design information is paramount and admits no tradeoff versus the confidence provided to the inspecting party in the accuracy and reproducibility of the measurements. The U.S. has reached an internal consensus on several critical design elements that define a general standard for radiation signature information barrier design. These criteria have stood the test of time under intense

  7. Floating barrier

    Energy Technology Data Exchange (ETDEWEB)

    1968-05-06

    This floating barrier consists of relatively long elements which can be connected to form a practically continuous assembly. Each element consists of an inflatable tube with an apron of certain height, made of impregnated fabric which is resistant to ocean water and also to hydrocarbons. Means for connecting one element to the following one, and means for attaching ballast to the apron are also provided.

  8. Morphological Modeling of a Low-Dune Barrier Headland System's Response to Hurricane Forcing Before and After a Large Scale Restoration

    Science.gov (United States)

    Johnson, C.; Chen, Q. J.

    2017-12-01

    Coastal barrier landforms serve as the first line of defense against oceanic and meteorological forcing. Widespread recognition of this function has prompted coastal managers to adopt systematic restoration programs. The state of Louisiana has, in response to its critically eroding shorelines (Byrnes et al., 2017), implemented 30 barrier island and headland restoration projects over the past three decades. The Caminada Headlands Beach and Dune Restoration Project, completed in 2016, restored 22.5 kilometers of Louisiana's coastline by elevating the cross-shore profile and placing approximately 250,000 m3 of sediment within the back- and foreshore. Interventions of this magnitude are significant perturbations to the local sediment budget and geomorphodynamic equilibrium. In Louisiana, an important question is the immediate fate of placed sediment transported during the passage of a hurricane, as the potential to ultimately retain this sediment is influenced by the location of its deposition. The direction of net sediment transport (on- or offshore) depends mainly on the elevation of the storm surge relative to the dune crest, but also on the evolution of the cross-shore water surface gradient and the spatial configuration of biogeophysical properties and hard-structures (Sherwood et al., 2014; Smallegan et al., 2016) . Prior to its restoration, the Caminada headlands were generally of low elevation with the majority of dune crest extending less than 50 cm above MHW and several active breaches. Hurricanes Gustav (2008) and Isaac (2012) made landfall directly on the headlands with inundating storm surges that resulted in observed overwash deposition (Doran et al, 2009; Guy et al, 2013), i.e. landward directed sediment transport and deposition. An open-source process-based morphological model (XBeach) is used to study hurricane induced sediment transport for both pre- and post-restoration of the Caminada headlands. Hindcast pre-restoration simulations of Gustav's and

  9. U-Th dating reveals regional-scale decline of branching Acropora corals on the Great Barrier Reef over the past century

    Science.gov (United States)

    Clark, Tara R.; Roff, George; Zhao, Jian-xin; Feng, Yue-xing; Done, Terence J.; McCook, Laurence J.; Pandolfi, John M.

    2017-09-01

    Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (shifted baseline.

  10. Barriers against psychosocial communication: oncologists' perceptions.

    Science.gov (United States)

    Fagerlind, Hanna; Kettis, Åsa; Glimelius, Bengt; Ring, Lena

    2013-10-20

    To explore oncologists' psychosocial attitudes and beliefs and their perceptions regarding barriers against psychosocial communication. A questionnaire was distributed to oncologists in Sweden (n = 537). Questions covered demography, the Physician Psychosocial Beliefs Scale (PPBS), and barriers against psychosocial communication. Stepwise multiple regression was used to determine what factors contribute the most to the PPBS score and the total number of barriers and barriers affecting clinical practice, respectively. Spearman rank-order correlation was used to determine correlation between PPBS score and number of barriers. Questionnaire response rate was 64%. Mean PPBS value was 85.5 (range, 49 to 123; SD, 13.0). Most oncologists (93%) perceived one or more barriers in communicating psychosocial aspects with patients. On average, five different communication barriers were perceived, of which most were perceived to affect clinical practice. These barriers included insufficient consultation time, lack of resources for taking care of problems discovered, and lack of methods to evaluate patients' psychosocial health in clinical practice. There was a positive correlation (rs = 0.490; P barriers (ie, less psychosocially oriented oncologists perceived more barriers). Oncologists with supplementary education with a psychosocial focus perceived fewer barriers/barriers affecting clinical practice (P barriers affecting psychosocial communication in clinical practice. Interventions aiming to improve psychosocial communication must therefore be multifaceted and individualized to clinics and individual oncologists. It is important to minimize barriers to facilitate optimal care and treatment of patients with cancer.

  11. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-01-01

    positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking

  12. Renewable energy sources (RES) projects and their barriers on a regional scale: The case study of wind parks in the Dodecanese islands, Greece

    International Nuclear Information System (INIS)

    Oikonomou, Emmanouil K.; Kilias, Vassilios; Goumas, Aggelos; Rigopoulos, Alexandrous; Karakatsani, Eirini; Damasiotis, Markos; Papastefanakis, Dimitrios; Marini, Natassa

    2009-01-01

    The increasing energy challenges faced, in particular, by isolated communities, such as insular communities, call for an integrated, flexible and easy-to-apply methodology aiming at providing a list of renewable energy sources) (RES) projects capable to reduce green house gas (GHG) emissions, satisfy future energy forecasts and reach the objectives of international/national energy directives and obligations, as, for example, the ones set by the Kyoto Protocol by 2010. The EU project EMERGENCE 2010 developed such a methodology that is implemented here in the case study of wind parks in the Dodecanese islands in Greece. The results obtained consist of a final list of financially viable RES wind projects, for which various barriers have been previously identified and assessed. The additional advantages of the proposed methodology is that besides providing as an end result a comprehensive list of RES projects adopted to specific criteria and regional priorities, it also allows space for involving - from early stages - the local community and stakeholders in the decision-making process (participatory planning); in this way, the EMERGENCE 2010 methodology may assist towards the RES promotion and public acceptance, the profitability of RES investments and the regional sustainable development.

  13. Investigation on impact resistance of steel plate reinforced concrete barriers against aircraft impact. Pt.3: Analyses of full-scale aircraft impact

    International Nuclear Information System (INIS)

    Jun Mizuno; Norihide Koshika; Eiichi Tanaka; Atsushi Suzuki; Yoshinori Mihara; Isao Nishimura

    2005-01-01

    Steel plate reinforced concrete (SC) walls and slabs are structural members in which the rebars of reinforced concrete are replaced by steel plates. Steel plate reinforced concrete structures are more attractive structural design alternatives to reinforced concrete structures, especially with thick, heavily reinforced walls and slabs such as nuclear structures, because they enable a much shorter construction period, greater earthquake resistant and more cost effectiveness. Experimental and analytical studies performed by the authors have also shown that SC structures are much more effective in mitigating damage against scaled aircraft models , as described in Parts 1 and 2 of this study. The objective of Part 3 was to determine the protective capability of SC walls and roofs against a full-scale aircraft impact by conducting numerical experiments to investigate the fracture behaviors and limit thicknesses of SC panels and to examine the effectiveness of SC panels in detail under design conditions. Furthermore, a simplified method is proposed for evaluating the localized damage induced by a full-scale engine impact. (authors)

  14. Improved Barriers to Turbine Engine Fragments: Final Annual Report

    National Research Council Canada - National Science Library

    Shockey, Donald

    2002-01-01

    .... Previous large-scale fragment impact testing of comer peg-mounted fabric barriers indicated that the failure of the fabric around the pegged hole was a significant factor in the barrier's effectiveness...

  15. Catsius Clay Project. Calculation and Testing of Behaviour of Unsaturated Clay as Barrier in Radioactive Waste Repositories. Stage 2: Validation Exercises at Laboratory scale

    International Nuclear Information System (INIS)

    Alonso, E. E.; Alcoverro, J.

    1999-01-01

    Stage 2 of CATSIUS CLAY Project: Validation Exercises at Laboratory Scale includes two Benchmarks, Benchmark 2.1: Oedometer Suction Controlled Tests on Samples of compacted Boom Clay and Benchmark 2.2: Small Scale Weltting-Heating Test on Compacted Bentonite. BM 2.1 had two parts: BM 2.1A (volumetric deformation upon wetting-drying cycles) and BM 2.1 B (swelling pressure test). In BM 2.1A, participants were asked to model the results of a series of five tests on samples of compacted Boom clay. In BM 2.1B, a swelling pressure test in which suction, vertical and horizontal stresses were monitored, was proposed as a blind exercise. Participants were asked to use, without further changes, the models calibrated in BM 2.1A. This exercise provides an evaluation of the capabilities of current mechanical constitutive models for unsaturated clay behaviour. It was found that, even if a calibration exercise on the basis of known experimental data is satisfactory, blind predictions of tests involving different paths may prove difficult. The test set up for BM 2.2 consisted of a stainless stell cell filled with highly expansive compacted bentonite (S2 clay from Almeria, Spain). The clay was subjected to a simultaneous central heating and a progressive water inflow through the botton plate. Temperature at various locations within the sample and the boundary radial stress were monitored throughout the test. Water content distribution was also measured at the end of the experiment. Predictions for this benchmark required the solution of field equations for flow, temperature distribution and mechanical analysis. Model parameters were derived from the extensive set of available experiments on this clay. Comparison between model predictions and measurements revealed the significance of water transport in vapour phase, the difficulties to predict boundary stresses and the general good agreement between measured and calculated temperatures. The report provides a detailed accojnt of the

  16. Catsius Clay Project. Calculation and Testing of Behaviour of Unsaturated Clay as Barrier in Radioactive Waste Repositories. Stage 2: Validation Exercises at Laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E E; Alcoverro, J

    1999-07-01

    Stage 2 of CATSIUS CLAY Project: Validation Exercises at Laboratory Scale includes two Benchmarks, Benchmark 2.1: Oedometer Suction Controlled Tests on Samples of compacted Boom Clay and Benchmark 2.2: Small Scale Weltting-Heating Test on Compacted Bentonite. BM 2.1 had two parts: BM 2.1A (volumetric deformation upon wetting-drying cycles) and BM 2.1 B (swelling pressure test). In BM 2.1A, participants were asked to model the results of a series of five tests on samples of compacted Boom clay. In BM 2.1B, a swelling pressure test in which suction, vertical and horizontal stresses were monitored, was proposed as a blind exercise. Participants were asked to use, without further changes, the models calibrated in BM 2.1A. This exercise provides an evaluation of the capabilities of current mechanical constitutive models for unsaturated clay behaviour. It was found that, even if a calibration exercise on the basis of known experimental data is satisfactory, blind predictions of tests involving different paths may prove difficult. The test set up for BM 2.2 consisted of a stainless stell cell filled with highly expansive compacted bentonite (S2 clay from Almeria, Spain). The clay was subjected to a simultaneous central heating and a progressive water inflow through the botton plate. Temperature at various locations within the sample and the boundary radial stress were monitored throughout the test. Water content distribution was also measured at the end of the experiment. Predictions for this benchmark required the solution of field equations for flow, temperature distribution and mechanical analysis. Model parameters were derived from the extensive set of available experiments on this clay. Comparison between model predictions and measurements revealed the significance of water transport in vapour phase, the difficulties to predict boundary stresses and the general good agreement between measured and calculated temperatures. The report provides a detailed accojnt of the

  17. Deep repository - engineered barrier systems. Half scale tests to examine water uptake by bentonite pellets in a block-pellet backfill system

    International Nuclear Information System (INIS)

    Dixon, David; Lundin, Cecilia; Oertendahl, Ellinor; Hedin, Mikael; Ramqvist, Gunnar

    2008-12-01

    In order to examine the behaviour of water entering a section of tunnel that had recently been backfilled using a combination of bentonite pellets and compacted, smectitic clay blocks, a series of large-scale tests have been completed. These tests, done at a scale of approximately 0.5 that of an emplacement tunnel were completed in a mock-up constructed in the Buffer Laboratory at SKB's Aespoe Hard Rock Laboratory. A total of 12 tests, undertaken under well controlled conditions were completed, examining the effects of inflow rate, inflow location and time on assemblies of blocks and pellets. Water was supplied to the assembly at rates ranging from 0.1 to 2.5 l/min and the time for water exit, the exit location, potential for erosion of backfill, the rate of water uptake and resistance of the assembly to water influx were all monitored for periods of 3 to 7 days. The testing time was selected to simulate a reasonable duration for unanticipated backfilling interruption. Longer durations were not necessary and risked both the stability of the system and the loss of the early stage conditions through progression of swelling and homogenization. Testing determined that initial water movement through backfill is largely controlled by the pellets. Water influx of up to 30 l/h at a single location was diverted by the pellets forming essentially horizontal flow channels (pipes) along the chamber wall - pellet interface. These piping features directed the majority of the incoming water around the backfill and towards the unconfined downstream face of the assembly. The time required for the water to exit the assembly was dependant on a combination of inflow rate and distance that it needed to travel. Water typically exited the face of the backfill at well-defined location(s) and once established, these features remained for the duration of the test. The exiting water typically carried only limited eroded material but could cause some disruption of the downstream face of the

  18. Deep repository - engineered barrier systems. Half scale tests to examine water uptake by bentonite pellets in a block-pellet backfill system

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (AECL) (Canada)); Lundin, Cecilia (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Oertendahl, Ellinor (NCC (Sweden)); Hedin, Mikael (Aangpannefoereningen, Stockholm (Sweden)); Ramqvist, Gunnar (Eltekno AB (Sweden))

    2008-12-15

    In order to examine the behaviour of water entering a section of tunnel that had recently been backfilled using a combination of bentonite pellets and compacted, smectitic clay blocks, a series of large-scale tests have been completed. These tests, done at a scale of approximately 0.5 that of an emplacement tunnel were completed in a mock-up constructed in the Buffer Laboratory at SKB's Aespoe Hard Rock Laboratory. A total of 12 tests, undertaken under well controlled conditions were completed, examining the effects of inflow rate, inflow location and time on assemblies of blocks and pellets. Water was supplied to the assembly at rates ranging from 0.1 to 2.5 l/min and the time for water exit, the exit location, potential for erosion of backfill, the rate of water uptake and resistance of the assembly to water influx were all monitored for periods of 3 to 7 days. The testing time was selected to simulate a reasonable duration for unanticipated backfilling interruption. Longer durations were not necessary and risked both the stability of the system and the loss of the early stage conditions through progression of swelling and homogenization. Testing determined that initial water movement through backfill is largely controlled by the pellets. Water influx of up to 30 l/h at a single location was diverted by the pellets forming essentially horizontal flow channels (pipes) along the chamber wall - pellet interface. These piping features directed the majority of the incoming water around the backfill and towards the unconfined downstream face of the assembly. The time required for the water to exit the assembly was dependant on a combination of inflow rate and distance that it needed to travel. Water typically exited the face of the backfill at well-defined location(s) and once established, these features remained for the duration of the test. The exiting water typically carried only limited eroded material but could cause some disruption of the downstream face of

  19. Investigation on impact resistance of steel plate reinforced concrete barriers against aircraft impact. Pt.2: Simulation analysis of scale model impact tests

    International Nuclear Information System (INIS)

    Jun Mizuno; Norihide Koshika; Hiroshi Morikawa; Kentaro Wakimoto; Ryusuke Fukuda

    2005-01-01

    Steel plate reinforced concrete (SC) structure is one in which the rebars of conventional reinforced concrete (RC) structures are replaced with external steel plates attached to inner concrete with headed studs. SC structures are considered to be more effective than RC structures against aircraft impact, so their application to outer walls and roofs of risk-sensitive structures such as nuclear-related structures is expected to mitigate damage to critical components. The objective of this study was to investigate the fracture behavior and perforation thickness of SC panels against aircraft impact through impact tests and simulation analyses. Objectives of this paper are to analytically investigate the protection performance of SC panels against aircraft model impact through simulation analyses of 1/7.5 scale aircraft model impact tests presented in Part 1 of this study using a discrete element method (DEM), and to examine the applicability and validity of the DEM. Simulation analyses by a finite element method (FEM) were also performed to evaluate its applicability. The fracture process and damage to the SC test panels as well as the aircraft models are closely simulated by the discrete element analyses. The various impact responses and failure mechanisms, such as deceleration curves of projectile, velocity of debris from rear face and deformation mode of SC panels, are also simulated closely by the DEM analyses. The results of analyses confirm the shock-proof performance of SC panels against aircraft impact, and the applicability and validity of DEM for evaluating the complex phenomena of an aircraft impact against an SC panel. The finite element analysis closely simulates the deformation of the SC test panel and strains of rear steel plate where the global bending deformation mode is dominant. (authors)

  20. Sprache als Barriere (Language as a Barrier)

    Science.gov (United States)

    Mattheier, Klaus

    1974-01-01

    The concept of language barrier has its derivations in the fields of dialectology, sociology and psychology. In contemporary usage however, the concept has two meanings i.e. regional-cultural barrier and socio-cultural barrier. (Text is in German.) (DS)

  1. Economic alternatives for containment barriers

    International Nuclear Information System (INIS)

    Nicholson, P.J.; Jasperse, B.H.; Fisher, M.J.

    1997-01-01

    Fixation, barriers, and containment of existing landfills and other disposal areas are often performed by insitu auger type soil mixing and jet grouting. Cement or other chemical reagents are mixed with soil to form both vertical and horizontal barriers. Immobilization of contaminants can be economically achieved by mixing soil and the contaminants with reagents that solidify or stabilize the contaminated area. Developed in Japan, and relatively new to the United States, the first large scale application was for a vertical barrier at the Jackson Lake Dam project in 1986. This technology has grown in both the civil and environmental field since. The paper describes current United States practice for Deep Soil Mixing (over 12 meters in depth), and Shallow Soil Mixing for vertical barriers and stabilization/solidification, and Jet Grouting for horizontal and vertical barriers. Creating very low permeability barriers at depth with minimal surface return often makes these techniques economical when compared to slurry trenches. The paper will discuss equipment, materials, soil and strength parameters, and quality control

  2. The natural and artificial hydration of a bentonite engineered barrier system in a full-scale KBS-3V mock-up; results from the first 7 years of the large scale gas injection test (LASGIT)

    International Nuclear Information System (INIS)

    Cuss, R.J.; Harrington, J.F.; Noy, D.J.; Bennett, D.P.; Sellin, P.

    2012-01-01

    Document available in extended abstract form only. The Large scale gas injection test is a full-scale in situ canister test designed to answer specific questions regarding the movement of gas through bentonite in a mock KBS-3v deposition hole. The test is located at 420 m depth within SKB's Aespoe Hard Rock Laboratory (HRL) in Sweden. The objective of Lasgit is to provide quantitative data to improve process understanding and test/validate modelling approaches which might be used in performance assessment. The deposition hole has a depth of 8.5 m and a diameter of around 1.75 m. A full scale KBS-3 canister has been modified for the Lasgit experiment with thirteen circular filters of varying dimensions located on its surface to provide point sources for gas injection, mimicking potential canister defects. These filters can also be used to inject water during the hydration stage, with hydration also conducted through 4 filter mats within the buffer. The deposition hole, buffer and canister are equipped with instrumentation to measure the total stress, pore water pressure and relative humidity in 32, 26 and 7 positions respectively. Additional instrumentation continually monitors variations in temperature, relative displacement of the lid and the restraining forces on the rock anchors. Groundwater inflow through a number of highly-conductive discrete fractures quickly resulted in elevated pore water pressures in sections of the borehole. This lead to the formation of conductive channels, the extrusion of bentonite from the deposition hole, and the discharge of groundwater to the gallery floor. Artificial hydration began after 106 days of testing. Up until the first gas injection test (day 843), the pressures in all of the canister filters and hydration mats were used to hydrate the clay. Initial attempts to raise pore water pressure in the artificial hydration arrays occasionally resulted in the formation of preferential pathways resulting in localized increases in

  3. Barriers and strategies for innovations entering BoP markets

    NARCIS (Netherlands)

    Kamp, L.M.; Ortt, J.R.; Harahap, B.

    2015-01-01

    Companies that bring a new product to the market or enter a new market with an existing product, come across a number of barriers that prevent large?scale diffusion. In order to circumvent or remove these barriers, they can adopt alternative strategies. This paper looks into these barriers and

  4. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-05-06

    Various methods and systems are provided for smart parking barriers. In one example, among others, a smart parking barrier system includes a movable parking barrier located at one end of a parking space, a barrier drive configured to control positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking space and a second position that allows access to the parking space. The parking controller can initiate movement of the movable parking barrier in response to a positive identification of an individual allowed to use the parking space. The parking controller can identify the individual through, e.g., a RFID tag, a mobile device (e.g., a remote control, smartphone, tablet, etc.), an access card, biometric information, or other appropriate identifier.

  5. Barrier cell sheath formation

    International Nuclear Information System (INIS)

    Kesner, J.

    1980-04-01

    The solution for electrostatic potential within a simply modeled tandem mirror thermal barrier is seen to exhibit a sheath at each edge of the cell. The formation of the sheath requires ion collisionality and the analysis assmes that the collisional trapping rate into the barrier is considerably slower than the barrier pump rate

  6. Barriers to physical activity among working mothers.

    Science.gov (United States)

    Dombrowski, Jill J

    2011-04-01

    Working mothers experience several barriers to physical activity. If these barriers can be identified by occupational health nurses and they can partner with working mothers to reduce these perceived barriers, the health of these workers can be improved and chronic disease risk prevented. The purpose of this study was to measure the effect of self-regulatory efficacy on physical activity among working mothers and to describe specific barriers to physical activity. The Barriers Specific Self-Efficacy Scale (BARSE) and the Kaiser Physical Activity Survey (KPAS) were used to measure the variables. Self-regulatory efficacy was found to be a strong predictor of physical activity in a diverse sample of working mothers who did not meet current recommendations for physical activity. Occupational health nurses can use these findings to design programs for groups and for counseling individuals. Copyright 2011, SLACK Incorporated.

  7. Barriers to fusion

    International Nuclear Information System (INIS)

    Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    1999-01-01

    The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

  8. Extremal surface barriers

    International Nuclear Information System (INIS)

    Engelhardt, Netta; Wall, Aron C.

    2014-01-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

  9. Safety- barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2008-01-01

    Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault...... trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management....

  10. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk...... analysis with operational safety management....

  11. Field study plan for alternate barriers

    International Nuclear Information System (INIS)

    Freeman, H.D.; Gee, G.W.; Relyea, J.F.

    1989-05-01

    Pacific Northwest Laboratory (PNL) is providing technical assistance in selecting, designing, evaluating, and demonstrating protective barriers. As part of this technical assistance effort, asphalt, clay, and chemical grout will be evaluated for use as alternate barriers. The purpose of the subsurface layer is to reduce the likelihood that extreme events (i.e., 100-year maximum storms, etc.) will cause significant drainage through the barrier. The tests on alternate barriers will include laboratory and field analysis of the subsurface layer performance. This field test plan outlines the activities required to test and design subsurface moisture barriers. The test plan covers activities completed in FY 1988 and planned through FY 1992 and includes a field-scale test of one or more of the alternate barriers to demonstrate full-scale application techniques and to provide performance data on a larger scale. Tests on asphalt, clay, and chemical grout were initiated in FY 1988 in small (30.5 cm diameter) tube-layer lysimeters. The parameters used for testing the materials were different for each one. The tests had to take into account the differences in material characteristics and response to change in conditions, as well as information provided by previous studies. 33 refs., 8 figs., 1 tab

  12. Differential Rollover Risk in Vehicle-to-Traffic Barrier Collisions

    Science.gov (United States)

    Gabauer, Douglas J.; Gabler, Hampton C.

    2009-01-01

    In the roadside safety community, there has been debate over the influence of vehicle and barrier type on rollover rates in traffic barrier crashes. This study investigated rollover rates between sport utility vehicles (SUVs), pickup trucks, and cars in vehicle-traffic barrier crashes and has examined the effect of barrier type on rollover risk for concrete barrier and metal barrier impacts. The analysis included 955 barrier impact cases that were selected from 11-years of in-depth crash data available through the National Automotive Sampling System (NASS) / Crashworthiness Data System (CDS). In real world tow-away level longitudinal barrier collisions, the most important predictors of vehicle rollover were found to be vehicle type and whether the vehicle was tracking prior to barrier impact. Based on binary logistic regression, SUVs were found to have 8 times the risk of rollover as cars in barrier impacts. Although pickups were found to have an increased risk of rollover compared to cars, the risk was not as pronounced as that found for SUVs. This finding has direct implications for the full scale crash testing of longitudinal barriers as the testing procedures have been predicated on the assumption that the pickup truck provides a critical or worst case impact scenario. In towaway crashes, our study does not support the notion that concrete barriers have a higher risk of vehicle rollover than metal beam barriers. PMID:20184839

  13. Multilayer moisture barrier

    Science.gov (United States)

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy

    2015-04-21

    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  14. Barrier penetration database

    International Nuclear Information System (INIS)

    Fainberg, A.; Bieber, A.M. Jr.

    1978-11-01

    This document is intended to supply the NRC and nuclear power plant licensees with basic data on the times required to penetrate forcibly the types of barriers commonly found in nuclear plants. These times are necessary for design and evaluation of the physical protection system required under 10CFR73.55. Each barrier listed is described in detail. Minor variations in basic barrier construction that result in the same penetration time, are also described

  15. Transport barriers in plasmas

    International Nuclear Information System (INIS)

    Caldas, I L; Szezech, J D Jr; Kroetz, T; Marcus, F A; Roberto, M; Viana, R L; Lopes, S R

    2012-01-01

    We discuss the creation of transport barriers in magnetically confined plasmas with non monotonic equilibrium radial profiles. These barriers reduce the transport in the shearless region (i.e., where the twist condition does not hold). For the chaotic motion of particles in an equilibrium electric field with a nonmonotonic radial profile, perturbed by electrostatic waves, we show that a nontwist transport barrier can be created in the plasma by modifying the electric field radial profile. We also show non twist barriers in chaotic magnetic field line transport in the plasma near to the tokamak wall with resonant modes due to electric currents in external coils.

  16. Converse Barrier Certificate Theorems

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2016-01-01

    This paper shows that a barrier certificate exists for any safe dynamical system. Specifically, we prove converse barrier certificate theorems for a class of structurally stable dynamical systems. Other authors have developed a related result by assuming that the dynamical system has neither...

  17. Skin barrier function

    DEFF Research Database (Denmark)

    2016-01-01

    Renowned experts present the latest knowledge Although a very fragile structure, the skin barrier is probably one of the most important organs of the body. Inward/out it is responsible for body integrity and outward/in for keeping microbes, chemicals, and allergens from penetrating the skin. Since...... the role of barrier integrity in atopic dermatitis and the relationship to filaggrin mutations was discovered a decade ago, research focus has been on the skin barrier, and numerous new publications have become available. This book is an interdisciplinary update offering a wide range of information...... on the subject. It covers new basic research on skin markers, including results on filaggrin and on methods for the assessment of the barrier function. Biological variation and aspects of skin barrier function restoration are discussed as well. Further sections are dedicated to clinical implications of skin...

  18. Barriers to the future

    Energy Technology Data Exchange (ETDEWEB)

    Massey, C T

    1986-09-01

    Opportunities for the British coal industry seem vast yet there are still barriers to progress. Seven areas are identified and discussed: mining mobility (for example, longwall mining systems are rigid and inflexible compared with American stall and pillar working); mine structure (many mines are more suitable to pit ponies than to large pieces of equipment); financial barriers (Government requires the industry to break even in 1987/88); personnel barriers (less specialization, better use of skills); safety barriers (increased use of remote control, ergonomics and robotics to protect workers); microelectronic management (nationalization has cushioned management from the market place; there is a need for a more multidisciplinary approach to the industry); and legal barriers (most legislation in the past has been in response to accidents; legislation external to the industry but affecting it is more fundamental).

  19. Computer simulations of the random barrier model

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Dyre, Jeppe

    2002-01-01

    A brief review of experimental facts regarding ac electronic and ionic conduction in disordered solids is given followed by a discussion of what is perhaps the simplest realistic model, the random barrier model (symmetric hopping model). Results from large scale computer simulations are presented...

  20. Vehicle barrier systems

    International Nuclear Information System (INIS)

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper

  1. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work...

  2. Transport Barriers in Bootstrap Driven Tokamaks

    Science.gov (United States)

    Staebler, Gary

    2017-10-01

    Maximizing the bootstrap current in a tokamak, so that it drives a high fraction of the total current, reduces the external power required to drive current by other means. Improved energy confinement, relative to empirical scaling laws, enables a reactor to more fully take advantage of the bootstrap driven tokamak. Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is due to the suppression of turbulence primarily due to the large Shafranov shift. ExB velocity shear does not play a significant role in the transport barrier due to the high safety factor. It will be shown, that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift driven barrier formation. The ion energy transport is reduced to neoclassical and electron energy and particle transport is reduced, but still turbulent, within the barrier. Deeper into the plasma, very large levels of electron transport are observed. The observed electron temperature profile is shown to be close to the threshold for the electron temperature gradient (ETG) mode. A large ETG driven energy transport is qualitatively consistent with recent multi-scale gyrokinetic simulations showing that reducing the ion scale turbulence can lead to large increase in the electron scale transport. A new saturation model for the quasilinear TGLF transport code, that fits these multi-scale gyrokinetic simulations, can match the data if the impact of zonal flow mixing on the ETG modes is reduced at high safety factor. This work was supported by the U.S. Department of Energy under DE-FG02-95ER54309 and DE-FC02

  3. Near-Surface Engineered Environmental Barrier Integrity

    International Nuclear Information System (INIS)

    Piet, S.J.; Breckenridge, R.P.

    2002-01-01

    The INEEL Environmental Systems Research and Analysis (ESRA) program has launched a new R and D project on Near-Surface Engineered Environmental Barrier Integrity to increase knowledge and capabilities for using engineering and ecological components to improve the integrity of near-surface barriers used to confine contaminants from the public and the environment. The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions and enable improved solutions for future cleanup decisions. The research is planned to (a) improve the knowledge of degradation mechanisms (weathering, biological, geological, chemical, radiological, and catastrophic) in times shorter than service life, (b) improve modeling of barrier degradation dynamics, (c) develop sensor systems to identify degradation prior to failure, and (d) provide a better basis for developing and testing of new barrier systems to increase reliability and reduce the risk of failure. Our project combine s selected exploratory studies (benchtop and field scale), coupled effects accelerated aging testing and the meso-scale, testing of new monitoring concepts, and modeling of dynamic systems. The performance of evapo-transpiration, capillary, and grout-based barriers will be examined

  4. On the porosity of barrier layers

    Directory of Open Access Journals (Sweden)

    J. Mignot

    2009-09-01

    Full Text Available Barrier layers are defined as the layer between the pycnocline and the thermocline when the latter are different as a result of salinity stratification. We present a revisited 2-degree resolution global climatology of monthly mean oceanic Barrier Layer (BL thickness first proposed by de Boyer Montégut et al. (2007. In addition to using an extended data set, we present a modified computation method that addresses the observed porosity of BLs. We name porosity the fact that barrier layers distribution can, in some areas, be very uneven regarding the space and time scales that are considered. This implies an intermittent alteration of air-sea exchanges by the BL. Therefore, it may have important consequences for the climatic impact of BLs. Differences between the two computation methods are small for robust BLs that are formed by large-scale processes. However, the former approach can significantly underestimate the thickness of short and/or localized barrier layers. This is especially the case for barrier layers formed by mesoscale mechanisms (under the intertropical convergence zone for example and along western boundary currents and equatorward of the sea surface salinity subtropical maxima. Complete characterisation of regional BL dynamics therefore requires a description of the robustness of BL distribution to assess the overall impact of BLs on the process of heat exchange between the ocean interior and the atmosphere.

  5. Information barriers and authentication

    International Nuclear Information System (INIS)

    MacArthur, D.W.; Wolford, J.K.

    2001-01-01

    Acceptance of nuclear materials into a monitoring regime is complicated if the materials are in classified shapes or have classified composition. An attribute measurement system with an information barrier can be emplo,yed to generate an unclassified display from classified measurements. This information barrier must meet two criteria: (1) classified information cannot be released to the monitoring party, and (2) the monitoring party must be convinced that the unclassified output accurately represents the classified input. Criterion 1 is critical to the host country to protect the classified information. Criterion 2 is critical to the monitoring party and is often termed the 'authentication problem.' Thus, the necessity for authentication of a measurement system with an information barrier stems directly from the description of a useful information barrier. Authentication issues must be continually addressed during the entire development lifecycle of the measurement system as opposed to being applied only after the system is built.

  6. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  7. Protective barrier development: Overview

    International Nuclear Information System (INIS)

    Wing, N.R.; Gee, G.W.

    1990-01-01

    Protective barrier and warning marker systems are being developed to isolate wastes disposed of near the earth's surface at the Hanford Site. The barrier is designed to function in an arid to semiarid climate, to limit infiltration and percolation of water through the waste zone to near-zero, to be maintenance free, and to last up to 10,000 yr. Natural materials (e.g., fine soil, sand, gravel, riprap, clay, asphalt) have been selected to optimize barrier performance and longevity and to create an integrated structure with redundant features. These materials isolate wastes by limiting water drainage; reducing the likelihood of plant, animal, and human intrusion; controlling emission of noxious gases; and minimizing erosion. Westinghouse Hanford Company and Pacific Northwest Laboratory efforts to assess the performance of various barrier and marker designs will be discussed

  8. Engineered barriers: current status

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.P.

    1988-01-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  9. Skin barrier composition

    International Nuclear Information System (INIS)

    Osburn, F.G.

    1985-01-01

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices. (author)

  10. Skin barrier composition

    Energy Technology Data Exchange (ETDEWEB)

    Osburn, F G

    1985-06-12

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices.

  11. Measuring Perceived Barriers to Physical Activity in Adolescents.

    Science.gov (United States)

    Gunnell, Katie E; Brunet, Jennifer; Wing, Erin K; Bélanger, Mathieu

    2015-05-01

    Perceived barriers to moderate-to-vigorous physical activity (PA) may contribute to the low rates of moderate-to-vigorous PA in adolescents. We examined the psychometric properties of scores from the perceived barriers to moderate-to-vigorous PA scale (PB-MVPA) by examining composite reliability and validity evidence based on the internal structure of the PB-MVPA and relations with other variables. This study was a cross-sectional analysis of data collected in 2013 from adolescents (N = 507; Mage = 12.40, SD = .62) via self-report scales. Using exploratory and confirmatory factor analyses, we found that perceived barriers were best represented as two factors representing internal (e.g., "I am not interested in physical activity") and external (e.g., "I need equipment I don't have") dimensions. Composite reliability was over .80. Using multiple regression to examine the relationship between perceived barriers and moderate-to-vigorous PA, we found that perceived internal barriers were inversely related to moderate-to-vigorous PA (β = -.32, p barriers (p > .26). The PB-MVPA scale demonstrated evidence of score reliability and validity. To improve the understanding of the impact of perceived barriers on moderate-to- vigorous PA in adolescents, researchers should examine internal and external barriers separately.

  12. Fuzzy barrier distributions

    International Nuclear Information System (INIS)

    Piasecki, E.

    2009-01-01

    Heavy-ion collisions often produce a fusion barrier distribution with structures displaying a fingerprint of couplings to highly collective excitations [1]. Basically the same distribution can be obtained from large-angle quasi-elastic scattering, though here the role of the many weak direct-reaction channels is unclear. For 2 0N e + 9 0Z r we have observed the barrier structures expected for the highly deformed neon projectile, but for 2 0N e + 9 2Z r we find completely smooth distribution (see Fig.1). We find that transfer channels in these systems are of similar strength but single particle excitations are significantly stronger in the latter case. They apparently reduce the 'resolving power' of the quasi-elastic channel, what leads to smeared out, or 'fuzzy' barrier distribution. This is the first case when such a phenomenon has been observed.(author)

  13. Health Barriers to Learning

    Directory of Open Access Journals (Sweden)

    Delaney Gracy

    2014-01-01

    Full Text Available This article summarizes the results from a 2013 online survey with 408 principals and assistant principals in New York City public elementary and middle schools. The survey assessed three primary areas: health issues in the school, health issues perceived as barriers to learning for affected students, and resources needed to address these barriers. Eighteen of the 22 health conditions listed in the survey were considered a moderate or serious issue within their schools by at least 10% of respondents. All 22 of the health issues were perceived as a barrier to learning by between 12% and 87% of the respondents. Representatives from schools that serve a higher percentage of low-income students reported significantly higher levels of concern about the extent of health issues and their impact on learning. Respondents most often said they need linkages with organizations that can provide additional services and resources at the school, especially for mental health.

  14. Barrier Data Base user's guide

    International Nuclear Information System (INIS)

    Worrell, R.B.; Gould, D.J.; Wall, D.W.

    1977-06-01

    A special purpose data base for physical security barriers has been developed. In addition to barriers, the entities accommodated by the Barrier Data Base (BDB) include threats and references. A threat is established as a configuration of people and equipment which has been employed to penetrate (or attempt to penetrate) a barrier. References are used to cite publications pertinent to the barriers and threats in the data base. Utilization and maintenance of the Barrier Data Base is achieved with LIST, QUERY, ENTER, DELETE, and CHANGE commands which are used to manipulate the data base entities

  15. Geophysical characterization of subsurface barriers

    International Nuclear Information System (INIS)

    Borns, D.J.

    1995-08-01

    An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

  16. FEBEX: Full-Scale engineered barriers experiment in crystalline host-rock: preoperational phase. Synthesized report; FEBEX: experimento de barreras de ingenieria a gran escala en rocas cristalinas: etapa preoperacional. Informe de sintesis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The FEBEX project is being cofinanced by the EC under contract F 14WCT950006. In addition to the EC, seven partners from three countries of the EU. (France, Germany, and Spain) as well as one from EFTA (Switzerland) are participating in the project. ENRESA is the coordinating partner with NAGRA assisting in coordinating some aspects. The project consists of two large-scale tests and a series of complimentary laboratory tests. The work is being executed by the following organizations: CIEMAT, AITEMIN, UP-DIT (CIMNE), ULC, CSIC-Zaidin, and UPM (SPAIN) ANDRA and G.3S (FRANCE) GRS (GERMANY). This report includes a synthesized description of the experiment from its conception through the installation of the two large-scale tests (from the middle of 1994 to the beginning of 1997, preoperation stage). The experiment is described in detail in a series of specific reports. (Author)

  17. Concrete road barriers subjected to impact loads: An overview

    Directory of Open Access Journals (Sweden)

    Muhammad Fauzi Bin Mohd. Zain

    Full Text Available Abstract Concrete barriers prevent vehicles from entering the opposite lane and going off the road. An important factor in the design of concrete barriers is impact load, which a vehicle exerts upon collision with a concrete barrier. This study suggests that a height of 813 mm, a base width of 600 mm, and a top width of 240 mm are optimum dimensions for a concrete barrier. These dimensions ensure the stability of concrete barriers during vehicle collisions. An analytical and experimental model is used to analyze the concrete barrier design. The LS-DYNA software is utilized to create the analytical models because it can effectively simulate vehicle impact on concrete barriers. Field tests are conducted with a vehicle, whereas laboratory tests are conducted with machines that simulate collisions. Full-scale tests allow the actual simulation of vehicle collisions with concrete barriers. In the vehicle tests, a collision angle of 25°, collision speeds of 100 km per hour, and a vehicle weighing more than 2 t are considered in the reviewed studies. Laboratory tests are performed to test bridge concrete barriers in static condition.

  18. Chaotic correlations in barrier billiards with arbitrary barriers

    International Nuclear Information System (INIS)

    Osbaldestin, A H; Adamson, L N C

    2013-01-01

    We study autocorrelation functions in symmetric barrier billiards for golden mean trajectories with arbitrary barriers. Renormalization analysis reveals the presence of a chaotic invariant set and thus that, for a typical barrier, there are chaotic correlations. The chaotic renormalization set is the analogue of the so-called orchid that arises in a generalized Harper equation. (paper)

  19. Design of engineered sorbent barriers

    International Nuclear Information System (INIS)

    Jones, E.O.; Freeman, H.D.

    1988-08-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper will cover the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier. 8 refs., 6 figs., 1 tab

  20. Design of engineered sorbent barriers

    International Nuclear Information System (INIS)

    Jones, E.O.; Freeman, H.D.

    1988-01-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper covers the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier

  1. Measuring Perceived Benefits and Perceived Barriers for Physical Activity

    Science.gov (United States)

    Brown, Seth A.

    2005-01-01

    Objectives: To evaluate the psychometric properties and relationship to physical activity levels of the Exercise Benefits/Barriers Scale (EBBS) among college students. Methods: A total of 398 college students completed the EBBS and a measure of self-efficacy, the Physical Exercise Self-Efficacy Scale. In addition, a subsample of 275 students also…

  2. A small-scale study investigating staff and student perceptions of the barriers to a preventative approach for adolescent self-harm in secondary schools in Wales-a grounded theory model of stigma.

    Science.gov (United States)

    Parker, Rachel

    2018-06-01

    Grounded theory analysis of secondary school staff and pupil perceptions about the barriers to preventative work for adolescent self-harm within the secondary school setting in Wales. Qualitative and grounded theory. Two secondary schools in Wales were purposefully sampled for variation. Four group interviews took place using qualitative research methods (Participatory Rapid Appraisal) with six school-based professionals and six students aged more than 16 years. Three pupil participants had long-term experience themselves of self-harming behaviours; all the remaining participants had encountered pupils who self-harmed. The research interviews were transcribed verbatim, generating school context-dependent information. This was analysed through the logic of abduction using the constant comparative grounded theory method because of its ability to focus on axial coding for context. The ontology that shaped this work was critical realism within a public health paradigm. A theoretical model of stigma resulted from the grounded theory analytical process, specifically in relation to staff and student perceptions about adolescent self-harm within the institutional context. This meant that social-based behaviours in the secondary school setting centred on the topic and behaviour of adolescent self-harm were structured by stigma. The findings of this study offer an explanation on the exclusion of adolescent self-harm from preventative work in secondary schools. The stigma model demonstrates that adolescent self-harm is excluded from the socio-cultural norms of the institutional setting. Applying the UK Equality Act (2010), this is discrimination. Further research on the institutional-level factors impacting adolescent self-harm in the secondary school context in England and Wales is now urgently needed. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  3. Understanding transport barriers through modelling

    International Nuclear Information System (INIS)

    Rozhansky, V

    2004-01-01

    Models of radial electric field formation are discussed and compared with the results of numerical simulations from fluid transport codes and Monte Carlo codes. A comparison of the fluid and Monte Carlo codes is presented. A conclusion is arrived at that all the simulations do not predict any bifurcation of the electric field, i.e. no bifurcation of poloidal rotation from low to high Mach number values is obtained. In most of the simulations, the radial electric field is close to the neoclassical electric field. The deviation from neoclassical electric field at the separatrix due to the existence of a transitional viscous layer is discussed. Scalings for the shear of the poloidal rotation are checked versus simulation results. It is demonstrated that assuming the critical shear to be of the order of 10 5 s -1 , it is possible to obtain a L-H transition power scaling close to that observed in the experiment. The dependence of the threshold on the magnetic field direction, pellet injection, aspect ratio and other factors are discussed on the basis of existing simulations. Transport codes where transport coefficients depend on the turbulence level and scenario simulations of L-H transition are analysed. However, the details of gyrofluid and gyrokinetic modelling should be discussed elsewhere. Simulations of internal transport barrier (ITB) formation are discussed as well as factors responsible for ITB formation

  4. Shottky-barrier formation

    International Nuclear Information System (INIS)

    Guines, F.; Sanchez-Dehesa, J.; Flores, F.

    1983-01-01

    In this paper a realistic selfconsistent calculation of an abrupt metal-semiconductor junction is presented by means of a tight-binding approach. A specific Si-Ag junction has been considered, and the charge neutrality level as well as the barrier height have been determined in good agreement with experiments. For a generaljunction it is shown that the interface properties depend essentially on the characteristics of the first metal layer and its interaction with the semiconductor. (Author) [pt

  5. Energy barrier to decoherence

    International Nuclear Information System (INIS)

    Mizel, Ari; Mitchell, M. W.; Cohen, Marvin L.

    2001-01-01

    We propose a ground-state approach to realizing quantum computers. This scheme is time-independent and inherently defends against decoherence by possessing an energy barrier to excitation. We prove that our time-independent qubits can perform the same algorithms as their time-dependent counterparts. Advantages and disadvantages of the time-independent approach are described. A model involving quantum dots is provided for illustration

  6. Surface barrier research at the Hanford Site

    International Nuclear Information System (INIS)

    Gee, G.W.; Ward, A.L.; Fayer, M.J.

    1997-01-01

    At the DOE Hanford Site, a field-scale prototype surface barrier was constructed in 1994 over an existing waste site as a part of a CERCLA treatability test. The above-grade barrier consists of a fine-soil layer overlying coarse layers of sands, gravels, basalt rock (riprap), and a low permeability asphalt layer. Two sideslope configurations, clean-fill gravel on a 10:1 slope and basalt riprap on a 2:1 slope, were built and are being tested. Design considerations included: constructability; drainage and water balance monitoring, wind and water erosion control and monitoring; surface revegetation and biotic intrusion; subsidence and sideslope stability, and durability of the asphalt layer. The barrier is currently in the final year of a three-year test designed to answer specific questions related to stability and long-term performance. One half of the barrier is irrigated such that the total water applied, including precipitation, is 480 mm/yr (three times the long-term annual average). Each year for the past two years, an extreme precipitation event (71 mm in 8 hr) representing a 1,000-yr return storm was applied in late March, when soil water storage was at a maximum. While the protective sideslopes have drained significant amounts of water, the soil cover (2-m of silt-loam soil overlying coarse sand and rock) has never drained. During the past year there was no measurable surface runoff or wind erosion. This is attributed to extensive revegetation of the surface. In addition, the barrier elevation has shown a small increase of 2 to 3 cm that is attributed to a combination of root proliferation and freeze/thaw activity. Testing will continue through September 1997. Performance data from the prototype barrier will be used by DOE in site-closure decisions at Hanford

  7. Performance of engineered barriers

    International Nuclear Information System (INIS)

    Rajaram, V.; Dean, P.V.; McLellan, S.A.

    1997-01-01

    Engineered barriers, both vertical and horizontal, have been used to isolate hazardous wastes from contact, precipitation, surface water and groundwater. The primary objective of this study was to determine the performance of subsurface barriers installed throughout the U.S. over the past 20 years to contain hazardous wastes. Evaluation of Resource Conservation and Recovery Act (RCRA) Subtitle C or equivalent caps was a secondary objective. A nationwide search was launched to select hazardous waste sites at which vertical barrier walls and/or caps had been used as the containment method. None of the sites selected had an engineered floor. From an initial list of 130 sites, 34 sites were selected on the basis of availability of monitoring data for detailed analysis of actual field performance. This paper will briefly discuss preliminary findings regarding the design, construction quality assurance/construction quality control (CQA/CQC), and monitoring at the 34 sites. In addition, the short-term performance of these sites (less than 5 years) is presented since very little long-term performance data was available

  8. Fluctuations in Schottky barrier heights

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1984-01-01

    A double Schottky barrier is often formed at the grain boundary in polycrystalline semiconductors. The barrier height is shown to fluctuate in value due to the random nature of the impurity positions. The magnitude of the fluctuations is 0.1 eV, and the fluctuations cause the barrier height measured by capacitance to differ from the one measured by electrical conductivity

  9. Transport barriers in bootstrap-driven tokamaks

    Science.gov (United States)

    Staebler, G. M.; Garofalo, A. M.; Pan, C.; McClenaghan, J.; Van Zeeland, M. A.; Lao, L. L.

    2018-05-01

    Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is caused by the suppression of turbulence primarily from the large Shafranov shift. It is shown that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift-driven barrier formation. Two self-organized states of the internal and edge transport barrier are observed. It is shown that these two states are controlled by the interaction of the bootstrap current with magnetic shear, and the kinetic ballooning mode instability boundary. Election scale energy transport is predicted to be dominant in the inner 60% of the profile. Evidence is presented that energetic particle-driven instabilities could be playing a role in the thermal energy transport in this region.

  10. Barrier mechanisms in the Drosophila blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Samantha Jane Hindle

    2014-12-01

    Full Text Available The invertebrate blood-brain barrier field is growing at a rapid pace and, in recent years, studies have shown a physiologic and molecular complexity that has begun to rival its vertebrate counterpart. Novel mechanisms of paracellular barrier maintenance through GPCR signaling were the first demonstrations of the complex adaptive mechanisms of barrier physiology. Building upon this work, the integrity of the invertebrate blood-brain barrier has recently been shown to require coordinated function of all layers of the compound barrier structure, analogous to signaling between the layers of the vertebrate neurovascular unit. These findings strengthen the notion that many blood-brain barrier mechanisms are conserved between vertebrates and invertebrates, and suggest that novel findings in invertebrate model organisms will have a significant impact on the understanding of vertebrate BBB functions. In this vein, important roles in coordinating localized and systemic signaling to dictate organism development and growth are beginning to show how the blood-brain barrier can govern whole animal physiologies. This includes novel functions of blood-brain barrier gap junctions in orchestrating synchronized neuroblast proliferation, and of blood-brain barrier secreted antagonists of insulin receptor signaling. These advancements and others are pushing the field forward in exciting new directions. In this review, we provide a synopsis of invertebrate blood-brain barrier anatomy and physiology, with a focus on insights from the past 5 years, and highlight important areas for future study.

  11. Dynamic simulation of collisions of heavy high-speed trucks with concrete barriers

    International Nuclear Information System (INIS)

    Itoh, Yoshito; Liu, Chunlu; Kusama, Ryuichi

    2007-01-01

    Real vehicle collision experiments on full-scale road safety barriers are important to determine the outcome of a vehicle versus barrier impact accident. However, such experiments require large investment of time and money. Numerical simulation has therefore been imperative as an alternative method for testing concrete barriers. In this research, spring subgrade models were first developed to simulate the ground boundary of concrete barriers. Both heavy trucks and concrete barriers were modeled using finite element methods (FEM) to simulate dynamic collision performances. Comparison of the results generated from computer simulations and on-site full-scale experiments demonstrated that the developed models could be applied to simulate the collision of heavy trucks with concrete barriers to provide the data to design new road safety barriers and analyze existing ones

  12. Barriers to accessing urethroplasty.

    Science.gov (United States)

    Consolo, Michael J; Syed, Kirin K; Robison, Christopher; McFadden, Jacob; Shalowitz, David I; Brown, Gordon A; Sussman, David O; Figler, Bradley D

    2016-01-01

    Urethroplasty is an effective treatment for men with anterior urethral strictures, but is utilized less frequently than ineffective treatments such as internal urethrotomy. We sought to identify provider-level barriers to urethroplasty. An anonymous online survey was emailed to all Mid-Atlantic American Urological Association members. Six scenarios in which urethroplasty was the most appropriate treatment were presented. Primary outcome was recommendation for urethroplasty in ≥ three clinical scenarios. Other factors measured include practice zip code, urethroplasty training, and proximity to a urethroplasty surgeon. Multivariate logistic regression identified factors associated with increased likelihood of urethroplasty recommendation. Of 670 members emailed, 109 (16%) completed the survey. Final analysis included 88 respondents. Mean years in practice was 17.2. Most respondents received formal training in urethroplasty: 43 (49%) in residency, 5 (6%) in fellowship, and 10 (11%) in both; 48 respondents (55%) had a urethroplasty surgeon in their practice, whereas 18 (20%) had a urethroplasty surgeon within 45 minutes of his or her primary practice location. The only covariate that was associated with an increased likelihood of recommending urethroplasty in ≥ three scenarios was formal urethroplasty training. Most members (68%) reported no barriers to referring patients for urethroplasty; the most common barriers cited were long distance to urethroplasty surgeon (n 5 13, 15%) and concern about complications (n 5 8, 9%). Urethroplasty continues to be underutilized in men with anterior urethral strictures, potentially due to lack of knowledge dissemination and access to a urethroplasty surgeon. Appropriate urethroplasty utilization may increase with greater exposure to urethroplasty in training.

  13. Racial Trade Barriers?

    DEFF Research Database (Denmark)

    Bjerre, Jacob Halvas

    . This paper analyzes the racial policies pursued in the foreign trade and argues that we need to recognize Aryanization as a world-wide policy in order to fully understand its character and possible consequences. I focus on the pre-war period and analyze the case of Denmark from three different perspectives......: perpetrators, victims and bystanders. The analysis will show that race, economy and foreign trade were combined in an attempt to raise racial trade barriers. This forced the question of German racial policies on the Danish government, Danish-Jewish businesses, and German companies involved in foreign trade...

  14. Support or Barrier?

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum; Lønsmann, Dorte

    This study offers a critical look at how corporate-level language management influences front-line language practices among employees in three multinational corporations (MNCs) headquartered in Scandinavia. Based on interview and document data, we examine, firstly, what front-line practices...... employees use to cross language boundaries in their everyday work, and, secondly, how these practices relate to top-down language management in the case companies. Our findings show that employees are often dependent on ad hoc and informal solutions in cross- language situations, which leads us...... to a discussion of how a company’s language policy may be seen as both support and a barrier....

  15. Conditions for plasmoid penetration across abrupt magnetic barriers

    International Nuclear Information System (INIS)

    Brenning, Nils; Hurtig, Tomas; Raadu, Michael A.

    2005-01-01

    The penetration of plasma clouds, or plasmoids, across abrupt magnetic barriers (of the scale less than a few ion gyro radii, using the plasmoid directed velocity) is studied. The insight gained earlier, from detailed experimental and computer simulation investigations of a case study, is generalized into other parameter regimes. It is concluded for what parameters a plasmoid should be expected to penetrate the magnetic barrier through self-polarization, penetrate through magnetic expulsion, or be rejected from the barrier. The scaling parameters are n e , v 0 , B perpendicular , m i , T i , and the width w of the plasmoid. The scaling is based on a model for strongly driven, nonlinear magnetic field diffusion into a plasma which is a generalization of the earlier laboratory findings. The results are applied to experiments earlier reported in the literature, and also to the proposed application of impulsive penetration of plasmoids from the solar wind into the Earth's magnetosphere

  16. MENDING THE IN SITU MANIPULATION BARRIER

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, S.W.

    2006-02-06

    In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations

  17. Stability of barrier buckets with zero RF-barrier separations

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.Y.; /Fermilab

    2005-03-01

    A barrier bucket with very small separation between the rf barriers (relative to the barrier widths) or even zero separation has its synchrotron tune decreasing rather slowly from a large value towards the boundary of the bucket. As a result, large area at the bucket edges can become unstable under the modulation of rf voltage and/or rf phase. In addition, chaotic regions may form near the bucket center and extend outward under increasing modulation. Application is made to those barrier buckets used in the process of momentum mining at the Fermilab Recycler Ring.

  18. Electrolyte diffusion in compacted montmorillonite engineered barriers

    International Nuclear Information System (INIS)

    Jahnke, F.M.; Radke, C.J.

    1985-09-01

    The bentonite-based engineered barrier or packing is a proposed component of several designs conceived to dispose of high-level nuclear waste in geologic repositories. Once radionuclides escape the waste package, they must first diffuse through the highly impermeable clay-rich barrier before they reach the host repository. To determine the effectiveness of the packing as a sorption barrier in the transient release period and as a mass-transfer barrier in the steady release period over the geologic time scales involved in nuclear waste disposal, a fundamental understanding of the diffusion of electrolytes in compacted clays is required. We present, and compare with laboratory data, a model quantifying the diffusion rates of cationic cesium and uncharged tritium in compacted montmorillonite clay. Neutral tritium characterizes the geometry (i.e., tortuosity) of the particulate gel. After accounting for cation exchange, we find that surface diffusion is the dominant mechanism of cation transport, with an approximate surface diffusion coefficient of 2 x 10 -6 cm 2 /s for cesium. This value increases slightly with increasing background ionic strength. The implications of this work for the packing as a migration barrier are twofold. During the transient release period, K/sub d/ values are of little importance in retarding ion migration. This is because sorption also gives rise to a surface diffusion path, and it is surface diffusion which controls the diffusion rate of highly sorbing cations in compacted montmorillonite. During the steady release period, the presence of surface diffusion leads to a flux through the packing which is greatly enhanced. In either case, if surface diffusion is neglected, the appropriate diffusion coefficient of ions in compacted packing will be in considerable error relative to current design recommendations. 11 refs., 4 figs., 1 tab

  19. Performing a local barrier operation

    Science.gov (United States)

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-03-04

    Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value of the counter, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

  20. Barrier rf systems in synchrotrons

    International Nuclear Information System (INIS)

    Bhat, Chandra M.

    2004-01-01

    Recently, many interesting applications of the barrier RF system in hadron synchrotrons have been realized. A remarkable example of this is the development of longitudinal momentum mining and implementation at the Fermilab Recycler for extraction of low emittance pbars for the Tevatron shots. At Fermilab, we have barrier RF systems in four different rings. In the case of Recycler Ring, all of the rf manipulations are carried out using a barrier RF system. Here, the author reviews various uses of barrier rf systems in particle accelerators including some new schemes for producing intense proton beam and possible new applications

  1. Tunnel superpenetrability of potential barriers

    International Nuclear Information System (INIS)

    Zakhariev, B N.

    1982-01-01

    The transmission of two particles through the same barrier is considered. The limiting cases are compared when the particles are joined together in a single particle with double mass-energy and potential and when they pass the barrier independently. As an intermediate case a pair of particles bound in a quasideuteron of a finite size is considered. It is shown that long-range collective correlations of particles (of the superfluidity type and others) simplify very much for them passing through high potential barriers. This happens due to the transfer of the additional energy from the particles outside the barriers to those inside it

  2. Barriers for recess physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Tjørnhøj-Thomsen, Tine; Schipperijn, Jasper

    2014-01-01

    BACKGROUND: Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender...... differences in children's perceptions of barriers to recess physical activity. Based on the socio-ecological model four types of environmental barriers were distinguished: natural, social, physical and organizational environment. METHODS: Data were collected through 17 focus groups (at 17 different schools...... this study, we recommend promoting recess physical activity through a combination of actions, addressing barriers within the natural, social, physical and organizational environment....

  3. Electronic health records: what are the most important barriers?

    Science.gov (United States)

    Ayatollahi, Haleh; Mirani, Nader; Haghani, Hamid

    2014-01-01

    The process of design and adoption of electronic health records may face a number of barriers. This study aimed to compare the importance of the main barriers from the experts' point of views in Iran. This survey study was completed in 2011. The potential participants (62 experts) included faculty members who worked in departments of health information technology and individuals who worked in the Ministry of Health in Iran and were in charge of the development and adoption of electronic health records. No sampling method was used in this study. Data were collected using a Likert-scale questionnaire ranging from 1 to 5. The validity of the questionnaire was established using content and face validity methods, and the reliability was calculated using Cronbach's alpha coefficient. The response rate was 51.6 percent. The participants' perspectives showed that the most important barriers in the process of design and adoption of electronic health records were technical barriers (mean = 3.84). Financial and ethical-legal barriers, with the mean value of 3.80 were other important barriers, and individual and organizational barriers, with the mean values of 3.59 and 3.50 were found to be less important than other barriers from the experts' perspectives. Strategic planning for the creation and adoption of electronic health records in the country, creating a team of experts to assess the potential barriers and develop strategies to eliminate them, and allocating financial resources can help to overcome most important barriers to the adoption of electronic health records.

  4. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... groups, the sociology of work needs to develop a better understanding of the way in which linguistic diversity influences the formation of social capital, i.e. resources such as the trust and reciprocity inherent in social relations in such workplaces. Drawing on theories about intergroup contact...... and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst...

  5. Countermeasures and barriers

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Johannes [Oersted - DTU, Automation, Kgs. Lyngby (Denmark)

    2005-10-01

    In 1973 Haddon proposed ten strategies for reducing and avoiding damages based on a model of potential harmful energy transfer (Haddon, 1973). The strategies apply to a large variety of unwanted phenomena. Haddon's pioneering work on countermeasures has had a major influence on later thinking about safety. Considering its impact it is remarkable that the literature offers almost no discussions related to the theoretical foundations of Haddon's countermeasure strategies. The present report addresses a number of theoretical issues related to Haddon's countermeasure strategies, which are: 1) A reformulation and formalization of Haddon's countermeasure strategies. 2) An identification and description of some of the problems associated with the term 'barrier'. 3) Suggestions for a more precise terminology based on the causal structure of countermeasures. 4) Extending the scope of countermeasures to include sign-based countermeasures. (au)

  6. Countermeasures and barriers

    International Nuclear Information System (INIS)

    Petersen, Johannes

    2005-10-01

    In 1973 Haddon proposed ten strategies for reducing and avoiding damages based on a model of potential harmful energy transfer (Haddon, 1973). The strategies apply to a large variety of unwanted phenomena. Haddon's pioneering work on countermeasures has had a major influence on later thinking about safety. Considering its impact it is remarkable that the literature offers almost no discussions related to the theoretical foundations of Haddon's countermeasure strategies. The present report addresses a number of theoretical issues related to Haddon's countermeasure strategies, which are: 1) A reformulation and formalization of Haddon's countermeasure strategies. 2) An identification and description of some of the problems associated with the term 'barrier'. 3) Suggestions for a more precise terminology based on the causal structure of countermeasures. 4) Extending the scope of countermeasures to include sign-based countermeasures. (au)

  7. Thames barrier (flood protection barriers on the Thames)

    International Nuclear Information System (INIS)

    Ilkovic, J.

    2005-01-01

    In this paper the flood protection barriers on the Thames are presented. The flood protection system on the Thames in 1984 was commissioned. During two decades this barrier was used 54 times against to the high water and 34 times against storm-sewage. There is installed buttress type hydroelectric power plant

  8. Long term performance of the Waterloo denitrification barrier

    International Nuclear Information System (INIS)

    Robertson, W.D.; Cherry, J.A.

    1997-01-01

    Beginning in 1991 a series of laboratory tests and small scale field trials were initiated to test the performance of an innovative permeable reactive barrier for treatment of nitrate from septic systems. The barrier promotes denitrification by providing an energy source in the form of solid organic carbon mixed into the porous media material. Advantages of the system for nitrate treatment are that the reaction is passive and in situ and it is possible to incorporate sufficient carbon mass in conveniently sized barriers to potentially provide treatment for long periods (decades) without the necessity for maintenance. However, longevity can only be demonstrated by careful long term monitoring of field installations. This paper documents four years of operating history at three small scale field trials; two where the denitrification barrier is installed as a horizontal layer positioned in the unsaturated zone below conventional septic system infiltration beds and one where the barrier is installed as a vertical wall intercepting a septic system plume at a downgradient location. The barriers have successfully attenuated 50-100% of NO - 3 -N levels of up to 170 mg/L and treatment has remained consistent over the four year period in each case, thus considerable longevity is indicated. Other field trials have demonstrated this technology to be equally effective in treating nitrogen contamination from other sources such as landfill leachate and farm field runoff

  9. Memory-induced acceleration and slowdown of barrier crossing

    Science.gov (United States)

    Kappler, Julian; Daldrop, Jan O.; Brünig, Florian N.; Boehle, Moritz D.; Netz, Roland R.

    2018-01-01

    We study the mean first-passage time τMFP for the barrier crossing of a single massive particle with non-Markovian memory by Langevin simulations in one dimension. In the Markovian limit of short memory time τΓ, the expected Kramers turnover between the overdamped (high-friction) and the inertial (low-friction) limits is recovered. Compared to the Markovian case, we find barrier crossing to be accelerated for intermediate memory time, while for long memory time, barrier crossing is slowed down and τMFP increases with τΓ as a power law τM F P˜τΓ2. Both effects are derived from an asymptotic propagator analysis: while barrier crossing acceleration at intermediate memory can be understood as an effective particle mass reduction, slowing down for long memory is caused by the slow kinetics of energy diffusion. A simple and globally accurate heuristic formula for τMFP in terms of all relevant time scales of the system is presented and used to establish a scaling diagram featuring the Markovian overdamped and the Markovian inertial regimes, as well as the non-Markovian intermediate memory time regime where barrier crossing is accelerated and the non-Markovian long memory time regime where barrier crossing is slowed down.

  10. Opportunities and barriers to straw construction

    DEFF Research Database (Denmark)

    White, Caroline Meyer; Howard, Thomas J.; Lenau, Torben Anker

    2012-01-01

    produced to support communication between clients and the consultants and facilitate the straw build design and decision making process. The intended audiences for the design guide are clients of small scale construction projects, architects, engineers, builders of straw construction, homeowner...... construction, and a series of qualitative interviews with a variety of stakeholders from previous straw build housing projects, results were gathered to find the most influential motives, barriers and considerations for straw build housing construction. Based on this empirical data, a design guide has been...

  11. CAPILLARY BARRIERS IN UNSATURATED FRACTURED ROCKS OF YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    Wu, Y.S.; Zhang, W.; Pan, L.; Hinds, J.; Bodvarsson, G.

    2000-01-01

    This work presents modeling studies investigating the effects of capillary barriers on fluid-flow and tracer-transport processes in the unsaturated zone of Yucca Mountain, Nevada, a potential site for storing high-level radioactive waste. These studies are designed to identify factors controlling the formation of capillary barriers and to estimate their effects on the extent of possible large-scale lateral flow in unsaturated fracture rocks. The modeling approach is based on a continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. Flow processes in fractured porous rock are described using a dual-continuum concept. In addition, approximate analytical solutions are developed and used for assessing capillary-barrier effects in fractured rocks. This study indicates that under the current hydrogeologic conceptualization of Yucca Mountain, strong capillary-barrier effects exist for significantly diverting moisture flow

  12. Control of electron internal transport barriers in TCV

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, M A; Behn, R; Coda, S; Condrea, I; Duval, B P; Goodman, T P; Karpushov, A; Martin, Y; Martynov, An; Moret, J-M; Nikkola, P; Porte, L; Sauter, O; Scarabosio, A; Zhuang, G [Centre de Recherches en Physique des Plasmas, Association EURATOM-Confederation Suisse, Ecole Polytechnique Federale de Lausanne, CRPP-EPFL, 1015 Lausanne (Switzerland)

    2004-05-01

    Current profile tailoring has been performed by application of electron cyclotron heating (ECH) and electron cyclotron current drive, leading to improved energy confinement in the plasma core of the TCV tokamak. The improved confinement is characterized by a substantial enhancement (H-factor) of the global electron energy confinement time relative to the prediction of the RLW scaling law (Rebut P H et al 1989 Proc. 12th Int. Conf. of Plasma Physics and Controlled Fusion Research (Nice, 1988) vol 2 (Vienna: IAEA) p 191), which predicts well Ohmic and standard ECH discharges on TCV. The improved confinement is attributed to a hollow current density profile producing a reversed shear profile creating an electron internal transport barrier. We relate the strength of the barrier to the depth of the hollow current density profile and the volume enclosed by the radial location of the peak current density. The {rho}{sub T}{sup *} (Tresset G et al 2002 Nucl. Fusion 42 520) criterion is used to evaluate the performance of the barrier relative to changes in the ECH parameters or the addition of Ohmic current, which aid in identifying the control parameters available for improving either the strength or volume of the barrier for enhanced performance. A figure of merit for the global scaling factor is used that scales the confinement enhancement as the product of the barrier volume and strength.

  13. Barriers associated with reduced physical activity in COPD patients.

    Science.gov (United States)

    Amorim, Priscila Batista; Stelmach, Rafael; Carvalho, Celso Ricardo Fernandes; Fernandes, Frederico Leon Arrabal; Carvalho-Pinto, Regina Maria; Cukier, Alberto

    2014-10-01

    To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score. In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

  14. Control of electron internal transport barriers in TCV

    International Nuclear Information System (INIS)

    Henderson, M A; Behn, R; Coda, S; Condrea, I; Duval, B P; Goodman, T P; Karpushov, A; Martin, Y; Martynov, An; Moret, J-M; Nikkola, P; Porte, L; Sauter, O; Scarabosio, A; Zhuang, G

    2004-01-01

    Current profile tailoring has been performed by application of electron cyclotron heating (ECH) and electron cyclotron current drive, leading to improved energy confinement in the plasma core of the TCV tokamak. The improved confinement is characterized by a substantial enhancement (H-factor) of the global electron energy confinement time relative to the prediction of the RLW scaling law (Rebut P H et al 1989 Proc. 12th Int. Conf. of Plasma Physics and Controlled Fusion Research (Nice, 1988) vol 2 (Vienna: IAEA) p 191), which predicts well Ohmic and standard ECH discharges on TCV. The improved confinement is attributed to a hollow current density profile producing a reversed shear profile creating an electron internal transport barrier. We relate the strength of the barrier to the depth of the hollow current density profile and the volume enclosed by the radial location of the peak current density. The ρ T * (Tresset G et al 2002 Nucl. Fusion 42 520) criterion is used to evaluate the performance of the barrier relative to changes in the ECH parameters or the addition of Ohmic current, which aid in identifying the control parameters available for improving either the strength or volume of the barrier for enhanced performance. A figure of merit for the global scaling factor is used that scales the confinement enhancement as the product of the barrier volume and strength

  15. Energy barriers in patterned media

    NARCIS (Netherlands)

    de Vries, Jeroen

    2013-01-01

    Due to the fact that thermal activation aids in overcoming the energy barrier, the required field for reversal varies from instance to instance for the same island. This thermally induced switching field distribution can be used to determine the difference in energy barrier of magneticallyweak and

  16. Simulating complex noise barrier reflections

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Lutgendorf, D.; Roo, F. de

    2011-01-01

    Within the EU FP7 QUIESST project, QUIeting the Environment for a Sustainable Surface Transport, a test method is being developed for the reflectivity of noise barriers. The method needs to account for a complex shape of barriers and the use of various types of absorbing materials. The performance

  17. BARRIERS OF STRATEGIC ALLIANCES ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Vladislav M. Sannikov

    2014-01-01

    Full Text Available General barriers of organization of different types of strategic alliances have beenconsidered in the article. There are several recommendations for overcoming themin cases of international alliances, and in case of work in one state. The article also identified goals and tasks of single coordination center of alliance to overcome organization barriers.

  18. TMX-U thermal-barrier experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Barter, J.D.

    1988-01-01

    This review of thermal-barrier experiments in the Tandem Mirror Experiment Upgrade (TMX-U) describes our progress at Lawrence Livermore National Laboratory in plasma confinement and central-cell heating. Thermal barriers in TMX-U improved axial confinement by two orders of magnitude over a limited range of densities, compared with confinement in single-cell mirrors at the same ion temperature. Our study shows that central-cell radial nonambipolar confinement scales as neoclassical theory and can be eliminated by floating the end walls. Radial ambipolar losses can also be measured and reduced. The electron energy balance is improved in tandem mirrors to near classical, resulting in T/sub e/ up to 0.28 keV. Electron cyclotron heating (ECH) efficiencies up to 42 percent, with low levels of electron microinstability, were achieved when hot electrons in the thermal barrier were heated to average betas as large as 15 percent. The hot-electron distribution is measured from X rays and is modeled by a Fokker-Planck code that includes heating from cavity radio-frequency (RF) fields. Neutral-beam injection in the central cell created average ion betas up to 5 percent with radial profiles of hot ions that are modeled accurately by a radial Fokker-Planck code. Gas fueling between two fundamental ion cyclotron heating (ICH) resonances resulted in symmetrical heating of passing ions toward both ends

  19. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    OpenAIRE

    Ansari, Walid El; Lovell, Geoff

    2009-01-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20-27 years) and older (28-35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants’ number of children was also noted...

  20. Tunnelling without barriers

    International Nuclear Information System (INIS)

    Lee, K.

    1987-01-01

    The evolution in flat and curved space-time of quantum fields in theories with relative flat potential and its consequences are considered. It is shown that bubble nucleation, a quantum mechanical tunnelling process, may occur in flat space-time, having a bounce solution, even if V(phi) has no barrier. It is shown that bubble nucleation can also occur in curved space-time even though there is no bounce solution in the standard formalism for the bubble nucleation rate in curved space-time. Additionally, bubbles can nucleate during the slow rolling period on the potential in flat and curved space-time, in this case also there is no bounce solution. It is known in the new inflationary scenario that energy density perturbations caused by quantum fluctuations of the scalar field can satisfy the presently observed bounds on density perturbations. Bubble nucleation during the slow rolling period also gives rise to density perturbations. For a model potential density perturbations by bubbles are calculated at the horizon reentering. By applying the bound from the almost isotropic microwave black body radiation on these density perturbations, a constraint on the model potential is obtained. Finally, some further implications on the galaxy formation and applications in more realistic potential are discussed

  1. Development of engineered barrier

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwan Sik; Cho, Won Jin; Lee, Jae Owan; Kim, Seung Soo; Kang, Mu Ja

    1999-03-01

    Engineered barrier development was carried out into the three research fields : waste form, disposal container, and buffer. The waste form field dealt with long-term leaching tests with borosilicate waste glasses surrounded by compacted bentonite. The leach rate decreased with increasing time, and was higher for the waste specimen rich in U and Na. In the container field, preliminary concepts of disposal containers were recommended by conducting structural analysis, thermal analysis, and shielding analysis, and major properties of stainless steel, copper, and titanium as a container material were surveyed. The sensitization degrees of SUS 316 and316L were lower than those of SUS 304 and 304L, respectively. The crevice corrosion of sensitized stainless steel was sensitive to the content of salt. Researches into the buffer included establishment of its performance criteria followed by investigating major properties of buffer using potential material in Korea. Experiments were made for measuring hydraulic conductivities, swelling properties, mechanical properties, thermal conductivities, pore-water chemistry properties, and adsorption properties was also investigated. (author)

  2. Omnidirectional ventilated acoustic barrier

    Science.gov (United States)

    Zhang, Hai-long; Zhu, Yi-fan; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-chun

    2017-11-01

    As an important problem in acoustics, sound insulation finds applications in a great variety of situations. In the existing schemes, however, there has always been a trade-off between the thinness of sound-insulating devices and their ventilating capabilities, limiting their potentials in the control of low-frequency sound in high ventilation environments. Here, we design and experimentally implement an omnidirectional acoustic barrier with a planar profile, subwavelength thickness ( 0.18 λ ), yet high ventilation. The proposed mechanism is based on the interference between the resonant scattering of discrete states and the background scattering of continuous states which induces a Fano-like asymmetric transmission profile. Benefitting from the binary-structured design of the coiled unit and hollow pipe, it maximally simplifies the design and fabrication while ensuring the ventilation for all the non-resonant units with open tubes. The simulated and measured results agree well, showing the effectiveness of our proposed mechanism to block low frequency sound coming from various directions while allowing 63% of the air flow to pass. We anticipate our design to open routes to design sound insulators and to enable applications in traditionally unattainable cases such as those calling for noise reduction and cooling simultaneously.

  3. Alternative geochemical barrier materials

    International Nuclear Information System (INIS)

    1991-07-01

    Previous investigations of the effects of neutralization and reduction on uranium mill tailings pore fluids by the Technical Support Contractor indicated that arsenic, selenium, and molybdenum continue to remain in solution in all but reducing conditions. These hazardous constituents are present in groundwaters as oxyanions and, therefore, are not expected to be removed by adsorption into clays and most other soil constituents. It was decided to investigate the attenuation capacity of two commonly available crystalline iron oxides, taconite and scoria, and a zeolite, a network aluminosilicate with a cage structure. Columns of the candidate materials were exposed to solutions of individual constituents, including arsenic, molybdenum, selenium, and, uranium, and to the spiked tailings pore fluid from the Bodo Canyon disposal cell near Durango, Colorado. In addition to the single material columns, a homogeneous blend of the three materials and layers of the materials were exposed to spiked tailings pore fluids. The results of these experiments indicate that with the exception of molybdenum, the constituents of concern are attenuated by the taconite; however, they are not sufficiently attenuated to meet the groundwater protection standards applicable to the UMTRA Project. Therefore, the candidate barrier materials did not prove to be useful to the UMTRA Project for the cleanup of groundwaters

  4. Mobilitet, barrierer & muligheder

    DEFF Research Database (Denmark)

    Petersen, Mimi

    2011-01-01

    stereotypering. På den ene side peger udsagn fra de unge drenge på en oplevelse af at blive kriminaliseret i kraft af deres køn (det maskuline kombineret med at have en anden hudfarve). Og de unge piger oplever, at de udover at blive kategoriseret som ”indvandrere” også bliver kategoriseret som passive, umyndige...... som en vej ud af irakiske Kurdistan, men ikke tilbage til Danmark. Drengene fra familier med bedre økonomiske ressourcer giver udtryk for, ønske om at rejse til andre lande. På grund af begrænsede sproglige kompetencer oplever hovedparten af de unge (både i Danmark og i irakiske Kurdistan) barrierer i...... har planer for at flytte fra Kurdistan. De har dansk statsborgerskab, men de vil ikke tilbage til Danmark. I de fortællinger, som afhandlingen bygger på, er det tydeligt at samspillet mellem flere sociale dimensioner, spiller ind på de unges selvforståelse, tilhørsforhold, erfaringer og deres valg af...

  5. Development of engineered barrier

    International Nuclear Information System (INIS)

    Chun, Kwan Sik; Cho, Won Jin; Lee, Jae Owan; Kim, Seung Soo; Kang, Mu Ja

    1999-03-01

    Engineered barrier development was carried out into the three research fields : waste form, disposal container, and buffer. The waste form field dealt with long-term leaching tests with borosilicate waste glasses surrounded by compacted bentonite. The leach rate decreased with increasing time, and was higher for the waste specimen rich in U and Na. In the container field, preliminary concepts of disposal containers were recommended by conducting structural analysis, thermal analysis, and shielding analysis, and major properties of stainless steel, copper, and titanium as a container material were surveyed. The sensitization degrees of SUS 316 and 316L were lower than those of SUS 304 and 304L, respectively. The crevice corrosion of sensitized stainless steel was sensitive to the content of salt. Researches into the buffer included establishment of its performance criteria followed by investigating major properties of buffer using potential material in Korea. Experiments were made for measuring hydraulic conductivities, swelling properties, mechanical properties, thermal conductivities, pore-water chemistry properties, and adsorption properties was also investigated. (author)

  6. Comparative studies for different proximity potentials applied to sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.L. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Beihang University, Key Laboratory of Micro-Nano Measurement-Manipulation and Physics (Ministry of Education), Beijing (China); Qu, W.W. [Medical College of Soochow University, School of Radiation Medicine and Protection, Soochow (China); Guo, M.F.; Qian, J.Q. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Zhang, H.Q. [China Institute of Atomic Energy, Beijing (China); Wolski, R. [Henryk Niewodniczanski Institute of Nuclear Physics PAS, Cracow (Poland)

    2016-02-15

    Coulomb barrier heights calculated by using 14 different versions of proximity potentials are studied and applied for experimental data of fusion in terms of a recently proposed energy scaling approach. The results show that the descriptions of proximity potentials 77 and 88 for the barrier heights seem to be closest to the values required by the systematics. On the basis of proximity potential 77, the parameterized formulas of the barrier height and radius are obtained. These formulas can calculate the barrier positions and barrier heights reasonably well within the error, respectively. Thus it provides a simple and direct way to calculate the barrier positions and barrier heights for heavy-ion fusion reactions. (orig.)

  7. Barriers to global health development: An international quantitative survey.

    Directory of Open Access Journals (Sweden)

    Bahr Weiss

    Full Text Available Global health's goal of reducing low-and-middle-income country versus high-income country health disparities faces complex challenges. Although there have been discussions of barriers, there has not been a broad-based, quantitative survey of such barriers.432 global health professionals were invited via email to participate in an online survey, with 268 (62% participating. The survey assessed participants' (A demographic and global health background, (B perceptions regarding 66 barriers' seriousness, (C detailed ratings of barriers designated most serious, (D potential solutions.Thirty-four (of 66 barriers were seen as moderately or more serious, highlighting the widespread, significant challenges global health development faces. Perceived barrier seriousness differed significantly across domains: Resource Limitations mean = 2.47 (0-4 Likert scale, Priority Selection mean = 2.20, Corruption, Lack of Competence mean = 1.87, Social and Cultural Barriers mean = 1.68. Some system-level predictors showed significant but relatively limited relations. For instance, for Global Health Domain, HIV and Mental Health had higher levels of perceived Social and Cultural Barriers than other GH Domains. Individual-level global health experience predictors had small but significant effects, with seriousness of (a Corruption, Lack of Competence, and (b Priority Selection barriers positively correlated with respondents' level of LMIC-oriented (e.g., weeks/year spent in LMIC but Academic Global Health Achievement (e.g., number of global health publications negatively correlated with overall barrier seriousness.That comparatively few system-level predictors (e.g., Organization Type were significant suggests these barriers may be relatively fundamental at the system-level. Individual-level and system-level effects do have policy implications; e.g., Priority Selection barriers were among the most serious, yet effects on seriousness of how LMIC-oriented a professional

  8. Perceived barriers to physical activity among Nigerian stroke survivors.

    Science.gov (United States)

    Idowu, Opeyemi Ayodiipo; Adeniyi, Ade Fatai; Ogwumike, Omoyemi Olubunmi; Fawole, Henrietta Oluwafunmilola; Akinrolie, Olayinka

    2015-01-01

    Benefits of physical activity in the prevention and management of stroke are well documented in the literature. There is increasing evidence that stroke survivors in South-West Nigeria are physically inactive. Data on barriers to the achievement of the recommended physical activity levels including its differences along socio-demographic characteristics among stroke survivors in South-West Nigeria are needed. The Exercise Benefits and Barrier Scale and the International Physical Activity Questionnaire were administered on 121 stroke survivors to determine their perceived barriers to physical activity and physical activity levels respectively. Information on socio-demographic data and clinical variables were also collected. The sample included 70.2% males, with majority of the participants reporting low physical activity levels (80.2%) and high perceived barriers (Mean = 48.13, SD = 7.88). The four most reported common barriers among stroke survivors were access to exercise facilities (95.0%), being embarrassed to exercise (94.2%), economic cost demands of exercise (94.2%) and notion that people in exercise clothes look funny (94.2%) respectively. There were no significant differences found in barriers to physical activity between gender (U = 1471.00, P = 0.74) and across each of: occupational status (H = 4.37, P = 0.22), age group (H = 0.82, P = 0.84) and educational levels (H = 4.56, P = 0.33). Significant difference however existed in perceived barriers across marital status categories (H = 12.87, P = 0.05). Stroke survivors indicated high perceived barriers to physical activity and these barriers were associated with marital status.

  9. Barrier-based micro/milli channels reactor

    NARCIS (Netherlands)

    Al-Rawashdeh, M.I.M.

    2013-01-01

    Gas-liquid processing in microreactors remains mostly restricted to the laboratory scale dueto the complexity and expenditure needed for an adequate numbering-up with a uniform flowdistribution. The barrier-based distributor is a multiphase flow distributor which assures flowuniformity and prevents

  10. Wave attenuation over the Great Barrier Reef matrix

    NARCIS (Netherlands)

    Gallop, S.; Young, I.; Ranasinghe, Ranasinghe W M R J B; Durrant, T.; Haigh, I.; Mynett, Arthur

    2015-01-01

    This is the first large-scale study of the influence of an offshore reef matrix on wave transmission. The focus was on the Great Barrier Reef (GBR), Australia, utilizing a 16 yr-record of wave height, from seven satellite altimeters. Within the GBR matrix, wave height is not strongly dependent on

  11. Engineered barrier experiment. Power control and data acquisition systems

    International Nuclear Information System (INIS)

    Alberdi, J.; Barcala, J.M.; Gamero, E.; Martin, P.L.; Molinero, A.; Navarrete, J.J.; Yuste, C.

    1997-01-01

    The engineered barrier concept for the storage of radioactive wastes is being tested at almost full scale at CIEMAT facilities. A data acquisition and control is an element of this experiment. This system would be operating for next three years. (Author)

  12. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh; Rungger, Ivan; Droghetti, Andrea; Sanvito, Stefano

    2014-01-01

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results

  13. Sediment Scaling for Mud Mountain Fish Barrier Structure

    Science.gov (United States)

    2017-06-28

    River serves as a collection point of migratory fish. Operators at the structure collect the fish and transport them upstream of Mud Mountain Dam...fixed weir does not allow for structure operations to mobilize the sediment. Thus, a new structure is desired to both mitigate sediment accumulation...gradation, respectively. This analysis should be based on a representative prototype gradation taken from non- slack water areas (Einstein 1950). For this

  14. Tritium/hydrogen barrier development

    International Nuclear Information System (INIS)

    Hollenberg, G.W.; Simonen, E.P.; Kalinen, G.; Terlain, A.

    1994-06-01

    A review of hydrogen permeation barriers that can be applied to structural metals used in fusion power plants is presented. Both implanted and chemically available hydrogen isotopes must be controlled in fusion plants. The need for permeation barriers appears strongest in Li17-Pb blanket designs, although barriers also appear necessary for other blanket and coolant systems. Barriers that provide greater than a 1000 fold reduction in the permeation of structural metals are desired. In laboratory experiments, aluminide and titanium ceramic coatings provide permeation reduction factors, PRFS, from 1000 to over 100,000 with a wide range of scatter. The rate-controlling mechanism for hydrogen permeation through these barriers may be related to the number and type of defects in the barriers. Although these barriers appear robust and resistant to liquid metal corrosion, irradiation tests which simulate blanket environments result in very low PRFs in comparison to laboratory experiments, i.e., <150. It is anticipated from fundamental research activities that the REID enhancement of hydrogen diffusion in oxides may contribute to the lower permeation reduction factors during in-reactor experiments

  15. Enershield : energy saving air barriers

    Energy Technology Data Exchange (ETDEWEB)

    Hallihan, D. [Enershield Industries Ltd., Edmonton, AB (Canada)

    2008-07-01

    Enershield Industries is a leader in air barrier technology and provides solution for the Canadian climate. This presentation described the advantages of air barriers and the impact of rising energy costs. An air barrier is used to separate areas of differing environments and makes existing building systems more efficient. This presentation discussed how an air barrier works. It also identified how Enershield Industries calculates energy savings. It described air barrier applications and those who use barrier technology. These include the commercial and industrial sector as well as the personnel and retail sector. Barrier technology can be used for cold storage; vehicle and equipment washes; food processing; and environmental separation. Features and benefits such as the ability to create seal, acoustic insulation, and long term durability were also discussed. Last, the presentation addressed model selection and design criteria issues. Design criteria that were presented included a discussion of acoustic installation, articulating nozzles, scroll cased fans, and structural frame. Other design criteria presented were galvanized frames, telescopic sliders, and off the shelf parts. It was concluded that the ability to reduce energy consumption and enhance employee/client comfort is beneficial to the employer as well as to the employee. figs.

  16. Penetration through the Skin Barrier

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates......-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous...

  17. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  18. Big Data as Information Barrier

    Directory of Open Access Journals (Sweden)

    Victor Ya. Tsvetkov

    2014-07-01

    Full Text Available The article covers analysis of ‘Big Data’ which has been discussed over last 10 years. The reasons and factors for the issue are revealed. It has proved that the factors creating ‘Big Data’ issue has existed for quite a long time, and from time to time, would cause the informational barriers. Such barriers were successfully overcome through the science and technologies. The conducted analysis refers the “Big Data” issue to a form of informative barrier. This issue may be solved correctly and encourages development of scientific and calculating methods.

  19. Barriers to cancer pain management in danish and lithuanian patients treated in pain and palliative care units

    DEFF Research Database (Denmark)

    Jacobsen, Ramune; Samsanaviciene, Jurgita; Liubarskiene, Zita

    2014-01-01

    -related barriers to cancer pain management in patient samples from Denmark and Lithuania. Thirty-three Danish and 30 Lithuanian patients responded to, respectively, Danish and Lithuanian versions of the Brief Pain Inventory pain scale, the Barriers Questionnaire II, the Hospital Anxiety and Depression Scale...

  20. CORRIDOR-TYPE BAFFLED MIXING BASIN WITH CROSS POROUS BARRIERS

    Directory of Open Access Journals (Sweden)

    S. M. Epoyan

    2018-02-01

    Full Text Available Purpose. The paper hightlights the increase in operational efficiency of corridor-type baffled mixing basin by installing of cross porous barriers made of gravel (or other materials and epoxy resin, grade ED-20 (ED-16 with the hardener polyethylenepolyamine (PEPA, approved by Ukrainian Ministry of Health in systems of utility and drinking water supply. Methodology. The first stage of the experiments was performed on the model of the proposed mixer in scale 1:4 in order to determine the local resistance of the porous barrier, which is made of gravel with a size of 10-15 mm (average diameter 12.5 mm and thickness of 50 mm. The local resistance of the barrier was measured using piezometers installed before and after the porous barrier. The velocity of water motion in the corridor of the mixer was determined depending on the water consumption, incoming on the mixer accordingly to the water meter and by the volumetric method. Findings. In accordance with researches when the water flows at a velocity of 0.1 m/s in the corridor of the mixer, the head losses in the porous barrier is 17 cm (0.17 m, and at a velocity of 0.2 m/s–0.68 m. The resistance coefficient (ξ, which is equal to 333.2 for the investigated barrier, was determined experimentally. It allows determining the head losses in the porous barrier at other velocities of water motion. When the velocity of water motion in the corridors of the mixer is from 0.7 up to 0.5 m/s, head losses increase almost fourfold. The conducted researches allowed to develop a calculation methodology for corridor-type baffled mixing basin with porous polymer-concrete barriers. Originality. Authors developed and investigated the corridor-type baffled mixing basin with porous polymer-concrete barriers. These barriers allow increasing and regulating the intensity and time of reagents mixing with the initial water exactly in the barriers, improving the distribution of the flow through the section of the mixer

  1. Fusion barrier characteristics of actinides

    Science.gov (United States)

    Manjunatha, H. C.; Sridhar, K. N.

    2018-03-01

    We have studied fusion barrier characteristics of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations. After the calculation of fusion barrier heights and positions, we have searched for their parameterization. We have achieved the empirical formula for fusion barrier heights (VB), positions (RB), curvature of the inverted parabola (ħω) of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations (6 projectile target combinations. The values produced by the present formula are also compared with experiments. The present pocket formula produces fusion barrier characteristics of actinides with the simple inputs of mass number (A) and atomic number (Z) of projectile-targets.

  2. Transport barrier in Helical system

    International Nuclear Information System (INIS)

    Ida, Katsumi

    1998-01-01

    Experiments on the transport barrier in Helical plasmas are reviewed. There are two mechanisms of transport improvement, that results in the formation of the transport barrier. One is the improvement of neoclassical transport by reducing the ripple loss with radial electric field, which exist only in helical plasma. The other is the improvement of anomalous transport due to the suppression of fluctuations associated with a radial electric field shear both in tokamak and helical plasma. The formation of the transport barrier can be triggered by the radial electric field shear associated with the transition of the radial electric field (L/H transition or ion-electron root transition) or the peaked density or the optimization of magnetic field shear. The mechanisms of transport barrier formation are also discussed. (author). 60 refs

  3. Coastal Structures and Barriers 2012

    Data.gov (United States)

    California Natural Resource Agency — This dataset is a compilation of the UCSC Sand Retention Structures, MC Barriers, and USACE Coastal Structures. UCSC Sand Retention Structures originate from a...

  4. Engineered barriers: current status 1989

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.B.

    1989-06-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain substantially the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide a measure of containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  5. Numerical simulation of flood barriers

    Science.gov (United States)

    Srb, Pavel; Petrů, Michal; Kulhavý, Petr

    This paper deals with testing and numerical simulating of flood barriers. The Czech Republic has been hit by several very devastating floods in past years. These floods caused several dozens of causalities and property damage reached billions of Euros. The development of flood measures is very important, especially for the reduction the number of casualties and the amount of property damage. The aim of flood control measures is the detention of water outside populated areas and drainage of water from populated areas as soon as possible. For new flood barrier design it is very important to know its behaviour in case of a real flood. During the development of the barrier several standardized tests have to be carried out. Based on the results from these tests numerical simulation was compiled using Abaqus software and some analyses were carried out. Based on these numerical simulations it will be possible to predict the behaviour of barriers and thus improve their design.

  6. Barriers to return to work after burn injuries.

    Science.gov (United States)

    Esselman, Peter C; Askay, Shelley Wiechman; Carrougher, Gretchen J; Lezotte, Dennis C; Holavanahalli, Radha K; Magyar-Russell, Gina; Fauerbach, James A; Engrav, Loren H

    2007-12-01

    To identify barriers to return to work after burn injury as identified by the patient. A cohort study with telephone interview up to 1 year. Hospital-based burn centers at 3 national sites. Hospitalized patients (N=154) meeting the American Burn Association criteria for major burn injury, employed at least 20 hours a week at the time of injury, and with access to a telephone after discharge. Patients were contacted via telephone every 2 weeks up to 4 months, then monthly up to 1 year after discharge. A return to work survey was used to identify barriers that prevented patients from returning to work. A graphic rating scale determined the impact of each barrier. By 1 year, 79.7% of patients returned to work. Physical and wound issues were barriers early after discharge. Although physical abilities continued to be a significant barrier up to 1 year, working conditions (temperature, humidity, safety) and psychosocial factors (nightmares, flashbacks, appearance concerns) became important issues in those with long-term disability. The majority of patients return to work after a burn injury. Although physical and work conditions are important barriers, psychosocial issues need to be evaluated and treated to optimize return to work.

  7. Material Barriers to Diffusive Mixing

    Science.gov (United States)

    Haller, George; Karrasch, Daniel

    2017-11-01

    Transport barriers, as zero-flux surfaces, are ill-defined in purely advective mixing in which the flux of any passive scalar is zero through all material surfaces. For this reason, Lagrangian Coherent Structures (LCSs) have been argued to play the role of mixing barriers as most repelling, attracting or shearing material lines. These three kinematic concepts, however, can also be defined in different ways, both within rigorous mathematical treatments and within the realm of heuristic diagnostics. This has lead to a an ever-growing number of different LCS methods, each generally identifying different objects as transport barriers. In this talk, we examine which of these methods have actual relevance for diffusive transport barriers. The latter barriers are arguably the practically relevant inhibitors in the mixing of physically relevant tracers, such as temperature, salinity, vorticity or potential vorticity. We demonstrate the role of the most effective diffusion barriers in analytical examples and observational data. Supported in part by the DFG Priority Program on Turbulent Superstructures.

  8. Air barrier systems: Construction applications

    Energy Technology Data Exchange (ETDEWEB)

    Perrault, J.C

    1989-01-01

    An examination is presented of how ordinary building materials can be used in an innovative manner to design, detail, and construct effective air barrier systems for common types of walls. For residential construction, the air drywall approach uses the interior gypsum board as the main component of the wall air barrier system. Joints between the gypsum board and adjacent materials or assemblies are sealed by gaskets. In commercial construction, two different techniques are employed for using gypsum board as air barrier material: the accessible drywall and non-accessible drywall approaches. The former is similar to the air drywall approach except that high performance sealants are used instead of gaskets. In the latter approach, exterior drywall sheathing is the main component of the air barrier system; joints between boards are taped and joints between boards and other components are sealed using elastomeric membrane strips. For various types of commercial and institutional buildings, metal air barrier systems are widely used and include pre-engineered curtain walls or sheet metal walls. Masonry wall systems are regarded as still the most durable, fireproof, and soundproof wall type available but an effective air barrier system has typically been difficult to implement. Factory-made elastomeric membranes offer the potential to provide airtightness to masonry walls. These membranes are applied on the entire masonry wall surface and are used to make airtight connections with other building components. Two types of product are available: thermofusible and peel-and-stick membranes. 5 figs.

  9. Explicating perceived barriers to mammography for the USCREEN project: concerns about breast implants, faith violations, and perceived recommendations.

    Science.gov (United States)

    Jensen, Jakob D; Ratcliff, Chelsea; Weaver, Jeremy; Krakow, Melinda M; Payton, William; Loewen, Sherrie

    2015-11-01

    In line with the health belief model, perceived barriers have proven to be a key determinant of intentions to screen for breast cancer. The standard measure of perceived barriers to breast cancer screening is an 11 item scale developed by Victoria Champion. However, perceived barriers emerge and change over time, and Champion's perceived barriers scale was last revised in 1999. Moreover, the original scale did not address barriers which may be more pronounced in particular populations, such as congruity of action with faith. As part of the Utah Screening Project, a sample of women 40-74 (N = 341, Mage = 51.19, SD = 8.11) were recruited from four Utah counties in 2014 to complete a survey. The results revealed that the four new perceived barrier items explained 6.4 % of intentions to screen, above and beyond other predictors. In addition to barriers identified in past research, the current study identified several novel barriers including (a) concerns about negative effects to breast implants, (b) perceived conflict with faith, and the (c) perception that mammography is no longer recommended. The new perceived barriers items are useful to researchers interested in exploring barriers not addressed by the original instrument. The barriers also suggest potential belief-based targets and channels (e.g., plastic surgery clinics, faith-based interventions) for delivering mammography interventions.

  10. On the generalized Hartman effect for symmetric double-barrier point potentials

    International Nuclear Information System (INIS)

    Lee, Molly A; Manzoni, Luiz A; Nyquist, Erik A; Lunardi, José T

    2015-01-01

    We consider the scattering of a non-relativistic particle by a symmetrical arrangement of two identical barriers in one-dimension, with the barriers given by the well-known four-parameter family of point interactions. We calculate the phase time and the stationary Salecker-Wigner-Peres clock time for the particular cases of a double δ and a double δ' barrier and investigate the off-resonance behavior of these time scales in the limit of opaque barriers, addressing the question of emergence of the generalized Hartman effect

  11. International Collaboration Activities on Engineered Barrier Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-08-31

    The Used Fuel Disposition Campaign (UFDC) within the DOE Fuel Cycle Technologies (FCT) program has been engaging in international collaborations between repository R&D programs for high-level waste (HLW) disposal to leverage on gathered knowledge and laboratory/field data of near- and far-field processes from experiments at underground research laboratories (URL). Heater test experiments at URLs provide a unique opportunity to mimetically study the thermal effects of heat-generating nuclear waste in subsurface repository environments. Various configurations of these experiments have been carried out at various URLs according to the disposal design concepts of the hosting country repository program. The FEBEX (Full-scale Engineered Barrier Experiment in Crystalline Host Rock) project is a large-scale heater test experiment originated by the Spanish radioactive waste management agency (Empresa Nacional de Residuos Radiactivos S.A. – ENRESA) at the Grimsel Test Site (GTS) URL in Switzerland. The project was subsequently managed by CIEMAT. FEBEX-DP is a concerted effort of various international partners working on the evaluation of sensor data and characterization of samples obtained during the course of this field test and subsequent dismantling. The main purpose of these field-scale experiments is to evaluate feasibility for creation of an engineered barrier system (EBS) with a horizontal configuration according to the Spanish concept of deep geological disposal of high-level radioactive waste in crystalline rock. Another key aspect of this project is to improve the knowledge of coupled processes such as thermal-hydro-mechanical (THM) and thermal-hydro-chemical (THC) operating in the near-field environment. The focus of these is on model development and validation of predictions through model implementation in computational tools to simulate coupled THM and THC processes.

  12. Diabetes and diet : managing dietary barriers

    NARCIS (Netherlands)

    Friele, R.D.

    1989-01-01

    This thesis reports on the barriers diabetic patients experience with their diet, and the ways they cope with these barriers. A dietary barrier is a hinderance to a person's well-being, induced by being advised a diet. First inventories were made of possible dietary barriers and ways of

  13. 24 CFR 574.645 - Coastal barriers.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Coastal barriers. 574.645 Section....645 Coastal barriers. In accordance with the Coastal Barrier Resources Act, 16 U.S.C. 3501, no financial assistance under this part may be made available within the Coastal Barrier Resources System. ...

  14. Barriers to activity and participation for stroke survivors in rural China.

    Science.gov (United States)

    Zhang, Lifang; Yan, Tiebin; You, Liming; Li, Kun

    2015-07-01

    To investigate environmental barriers reported by stroke survivors in the rural areas of China and to determine the impact of environmental barriers on activity and participation relative to demographic characteristics and body functioning. Cross-sectional survey. Structured interviews in the participants' homes. Community-dwelling stroke survivors in the rural areas of China (N=639). Not applicable. Activity and participation (Chinese version of the World Health Organization Disability Assessment Schedule 2.0), environmental barriers (Craig Hospital Inventory of Environmental Factors), neurological function (Canadian Neurological Scale), cognitive function (Abbreviated Mental Test), and depression (6-item Hamilton Rating Scale for Depression). Physical/structural barriers are the major impediment to activity and participation for these participants (odds ratio, 1.86 and 1.99 for activity and participation, respectively; Penvironmental barriers to be decreased and eliminated first. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  15. Study of the efficiency of the anti-convective thermal barrier of the Super-Phenix vessels inter space

    International Nuclear Information System (INIS)

    Durin, M.; Mejane, A.

    1983-08-01

    In the LMFBR Phenix reactor, the junction between the primary vessel and the roof slab is a region of large thermal gradients. In order to limit the gradient in the primary vessel, a thermal barrier has been installed between the primary and the safety vessel. The purpose of this barrier is to prevent the penetration of hot gas in the upper part of the vessels inter space. Experimental results have been obtained on a full scale model representing a 25 0 vessel sector of the reactor. Different geometrical configurations have been tested for a large range of boundary condition: - perfectly tight barrier - no thermal barrier; - simulation of leakages on the barrier [fr

  16. Pharmacogenetics in Europe: barriers and opportunities.

    Science.gov (United States)

    Gurwitz, D; Zika, E; Hopkins, M M; Gaisser, S; Ibarreta, D

    2009-01-01

    This paper reviews the current situation in the field of pharmacogenetics/pharmacogenomics (PGx) in Europe. High expectations surrounding the clinical application of PGx remain largely unmet, as only a limited number of such applications have actually reached the market and clinical practice. Thus, the potential impact of PGx-based diagnostics on healthcare and its socio-economic implications are still unclear. With the aim of shedding some light on these uncertainties, the Institute for Prospective Technological Studies (IPTS) of the European Commission's Joint Research Centre (JRC) has conducted a review of the 'state of the art' and a further analysis on the use of pharmacogenetics diagnostics for preventing toxic drug reactions and improving drug efficacy in Europe. The paper presents highlights from the JRC-IPTS studies and discusses possibilities for improving translation of PGx research in Europe by comparing some experiences in the USA. We also illustrate the related barriers for the clinical uptake of PGx in Europe with specific case-studies. Most of the barriers identified extend beyond the European context. This reflects the global problems of scarcity of data demonstrating proven clinical validity or utility and favorable cost-effectiveness studies to support the clinical application of PGx diagnostic tests in the clinical setting. Another key barrier is the lack of incentives for the private sector to invest in the development and licensing of PGx diagnostic tests for improving the safety and efficacy of out-of-patent drugs. It therefore seems that one key aspect where policy can affect the clinical uptake of PGx is via sustaining large-scale industry-academia collaborations for developing and proving the utility of PGx diagnostics. Copyright 2009 S. Karger AG, Basel.

  17. Overcoming Barriers to Successfully Commercializing Carbon Dioxide Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Kant, Marvin, E-mail: marvin.kant@tu-berlin.de [Department of Entrepreneurship and Innovation Management, Technische Universität Berlin, Berlin (Germany)

    2017-09-13

    The successful transition to a low-carbon economy hinges on innovative solutions and collaborative action on a global scale. Sustainable entrepreneurship is thereby recognized as a key driver in the creation and transformation of ecologically and socially sustainable economic systems. The purpose of this article is to contribute to this topic by understanding commercialization barriers for strong sustainability-oriented new technology ventures and to derive recommendations to overcome them. A qualitative multilevel approach is applied to identify barriers and drivers within the internal dynamic capabilities of the organization and within the organization’s external stakeholders. A model of barriers has been developed based on semi-structured interviews with new carbon dioxide utilization ventures and associated industry players in Canada, the USA, and the European Economic Area. Resulting recommendations to facilitate the (re-)design of a dedicated support system are proposed on four levels: (a) actors, (b) resources, (c) institutional settings, and (d) the coordination of the support system.

  18. Overcoming Barriers to Successfully Commercializing Carbon Dioxide Utilization

    International Nuclear Information System (INIS)

    Kant, Marvin

    2017-01-01

    The successful transition to a low-carbon economy hinges on innovative solutions and collaborative action on a global scale. Sustainable entrepreneurship is thereby recognized as a key driver in the creation and transformation of ecologically and socially sustainable economic systems. The purpose of this article is to contribute to this topic by understanding commercialization barriers for strong sustainability-oriented new technology ventures and to derive recommendations to overcome them. A qualitative multilevel approach is applied to identify barriers and drivers within the internal dynamic capabilities of the organization and within the organization’s external stakeholders. A model of barriers has been developed based on semi-structured interviews with new carbon dioxide utilization ventures and associated industry players in Canada, the USA, and the European Economic Area. Resulting recommendations to facilitate the (re-)design of a dedicated support system are proposed on four levels: (a) actors, (b) resources, (c) institutional settings, and (d) the coordination of the support system.

  19. Progress in forming bottom barriers under waste sites

    International Nuclear Information System (INIS)

    Carter, E.E.

    1997-01-01

    The paper describes an new method for the construction, verification, and maintenance of underground vaults to isolate and contain radioactive burial sites without excavation or drilling in contaminated areas. The paper begins with a discussion of previous full-scale field tests of horizontal barrier tools which utilized high pressure jetting technology. This is followed by a discussion of the TECT process, which cuts with an abrasive cable instead of high pressure jets. The new method is potentially applicable to more soil types than previous methods and can form very thick barriers. Both processes are performed from the perimeter of a site and require no penetration or disturbance of the active waste area. The paper also describes long-term verification methods to monitor barrier integrity passively

  20. A study on water infiltration barriers with compacted layered soils

    International Nuclear Information System (INIS)

    Umeda, Y.; Komori, K.; Fujiwara, A.

    1993-01-01

    In shallow-ground disposal of low-level radioactive wastes, water movements due to natural processes in the soil covering the disposal facility must be properly controlled. A capillary barrier with compacted layered soils can provide an effective means of controlling water movement in the soil covering placed on a low-level radioactive waste disposal facility. An experiment was performed to determine the effectiveness of a full-scale fill as a capillary barrier. The fill used in the experiment was constructed of compacted layers of clay, fine sand, and gravel. Man-made rain was caused to fall on the surfaces of the fill to observe the infiltration of rainwater into the fill and to measure the amount of water drained from within. The experiment established the effectiveness of the capillary barrier

  1. Expectations of barriers to psychosocial care: views of parents and adolescents in the community.

    Science.gov (United States)

    Nanninga, Marieke; Reijneveld, Sijmen A; Knorth, Erik J; Jansen, Danielle E M C

    2016-01-01

    Parents with a child suffering from psychosocial problems frequently experience barriers to psychosocial care, which may hinder access. Expectations of barriers may have the same effect, but evidence is lacking. The aim of this study is to examine parents' and adolescents' expectations of barriers regarding psychosocial care for the child, along with associated child and family characteristics. We obtained data on an age-stratified random sample of school children/pupils aged 4-18 via questionnaires (N = 666; response rate 70.3 %). Expectations of barriers to psychosocial care were measured with the "Barriers to Treatment Participation Scale-Expectancies" questionnaire (BTPS-exp). Results showed that 64 % of the parents of children below age 12, 59 % of the parents of adolescents (age 12-18), and 84 % of the adolescents expected one or more barriers. Parents and adolescents expected barriers most frequently with respect to irrelevance of treatment. Mainly parents with low educational level and their adolescents expected barriers regarding treatment, and quite a few characteristics of parents of adolescents were associated with expecting multiple barriers regarding treatment demands and issues, for example, single parents, parents of lower educational level and of adolescent boys, and parents of adolescents with psychosocial problems. We conclude that adolescents especially, but also their parents and parents of younger children, expect major barriers to psychosocial care, which may greatly hinder appropriate care seeking. This evidence may support professionals and policymakers in their attempts to improve access to psychosocial care.

  2. H2@Scale Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Pivovar, Bryan

    2017-03-31

    Final report from the H2@Scale Workshop held November 16-17, 2016, at the National Renewable Energy Laboratory in Golden, Colorado. The U.S. Department of Energy's National Renewable Energy Laboratory hosted a technology workshop to identify the current barriers and research needs of the H2@Scale concept. H2@Scale is a concept regarding the potential for wide-scale impact of hydrogen produced from diverse domestic resources to enhance U.S. energy security and enable growth of innovative technologies and domestic industries. Feedback received from a diverse set of stakeholders at the workshop will guide the development of an H2@Scale roadmap for research, development, and early stage demonstration activities that can enable hydrogen as an energy carrier at a national scale.

  3. Programmer's description of the Barrier Data Base

    International Nuclear Information System (INIS)

    Wall, D.W.; Jones, R.E.; Worrell, R.B.

    1976-12-01

    The Barrier Data Base is a body of information concerning different kinds of barriers that are used in safeguarding nuclear materials and installations. The two programs written for creating, updating, and manipulating the Barrier Data Base are discussed. The BARRIER program is used to add, delete, modify, display, or search for specific data in the data base. A utility program named NUMBER is used to compress and renumber the barrier and threat tables

  4. Skin Barrier Function and Allergens

    DEFF Research Database (Denmark)

    Engebretsen, Kristiane Aasen; Thyssen, Jacob Pontoppidan

    2016-01-01

    The skin is an important barrier protecting us from mechanical insults, microorganisms, chemicals and allergens, but, importantly, also reducing water loss. A common hallmark for many dermatoses is a compromised skin barrier function, and one could suspect an elevated risk of contact sensitization...... and skin barrier status. Psoriasis has traditionally been regarded a Th1-dominated disease, but the discovery of Th17 cells and IL-17 provides new and interesting information regarding the pathogenesis of the disease. Research suggests an inverse relationship between psoriasis and CA, possibly due......) and Th2 (AD) have been proposed as an explanation. Finally, there is convincing evidence that exposure to irritants increases the risk of CS, and patients with ICD are, therefore, at great risk of developing CA. Skin irritation leads to the release of IL-1 and TNF-α, which affects the function of antigen...

  5. Barrier mechanisms in the Drosophila blood-brain barrier.

    Science.gov (United States)

    Hindle, Samantha J; Bainton, Roland J

    2014-01-01

    The invertebrate blood-brain barrier (BBB) field is growing at a rapid pace and, in recent years, studies have shown a physiologic and molecular complexity that has begun to rival its vertebrate counterpart. Novel mechanisms of paracellular barrier maintenance through G-protein coupled receptor signaling were the first demonstrations of the complex adaptive mechanisms of barrier physiology. Building upon this work, the integrity of the invertebrate BBB has recently been shown to require coordinated function of all layers of the compound barrier structure, analogous to signaling between the layers of the vertebrate neurovascular unit. These findings strengthen the notion that many BBB mechanisms are conserved between vertebrates and invertebrates, and suggest that novel findings in invertebrate model organisms will have a significant impact on the understanding of vertebrate BBB functions. In this vein, important roles in coordinating localized and systemic signaling to dictate organism development and growth are beginning to show how the BBB can govern whole animal physiologies. This includes novel functions of BBB gap junctions in orchestrating synchronized neuroblast proliferation, and of BBB secreted antagonists of insulin receptor signaling. These advancements and others are pushing the field forward in exciting new directions. In this review, we provide a synopsis of invertebrate BBB anatomy and physiology, with a focus on insights from the past 5 years, and highlight important areas for future study.

  6. Desenvolvimento e validação da versão em português da Escala de Barreiras para Reabilitação Cardíaca Development and validation of the Brazilian Portuguese version of the Cardiac Rehabilitation Barriers Scale

    Directory of Open Access Journals (Sweden)

    Gabriela Lima de Melo Ghisi

    2012-04-01

    Full Text Available FUNDAMENTO: As doenças cardiovasculares possuem alta incidência e prevalência no Brasil, porém a participação na Reabilitação Cardíaca (RC é limitada e pouco investigada no país. A Escala de Barreiras para Reabilitação Cardíaca (CRBS foi desenvolvida para avaliar as barreiras à participação e aderência à RC. OBJETIVO: Traduzir, adaptar culturalmente e validar psicometricamente a CRBS para a língua portuguesa do Brasil. MÉTODOS: Duas traduções iniciais independentes foram realizadas. Após a tradução reversa, ambas versões foram revisadas por um comitê. A versão gerada foi testada em 173 pacientes com doença arterial coronariana (48 mulheres, idade média = 63 anos. Desses, 139 (80,3% participantes de RC. A consistência interna foi avaliada pelo alfa de Cronbach, a confiabilidade teste-reteste pelo coeficiente de correlação intraclasse (ICC e a validade de construto por análise fatorial. Testes-T foram utilizados para avaliar a validade de critério entre participantes e não participantes de RC. Os resultados da aplicação em função das características dos pacientes (gênero, idade, estado de saúde e grau de escolaridade foram avaliados. RESULTADOS: A versão em português da CRBS apresentou alfa de Cronbach de 0,88, ICC de 0,68 e revelou cinco fatores, cuja maioria apresentou-se internamente consistente e todos definidos pelos itens. O escore médio para pacientes em RC foi 1,29 (desvio padrão = 0,27 e para pacientes do ambulatório 2,36 (desvio padrão = 0,50 (p BACKGROUND: Cardiovascular diseases show high incidence and prevalence in Brazil; however, participation in Cardiac Rehabilitation (CR is limited and has been poorly investigated in the country. The Cardiac Rehabilitation Barriers Scale (CRBS was developed to assess the barriers to participation and adherence to CR. OBJECTIVE: To translate, cross-culturally adapt and psychometrically validate CRBS to Brazilian Portuguese. METHODS: Two independent

  7. Communication barriers in the family

    Directory of Open Access Journals (Sweden)

    BARBARA KOC-KOZŁOWIEC

    2017-10-01

    Full Text Available The art of communication – listening and speaking – is a major life skill, with a thorough influence on every human life. Remaining silent while the interlocutor speaks is not all that there is to the act of listening to messages. True listening is based on an intention to get involved in understanding of the other person, enjoying his or her presence, learning something from the conversation, giving assistance, or comforting the interlocutor. In the article the author describes obstacles (barriers, which render true listening impossible. These barriers have been identified by a group of young adults.

  8. Enhanced tunneling through nonstationary barriers

    International Nuclear Information System (INIS)

    Palomares-Baez, J. P.; Rodriguez-Lopez, J. L.; Ivlev, B.

    2007-01-01

    Quantum tunneling through a nonstationary barrier is studied analytically and by a direct numerical solution of Schroedinger equation. Both methods are in agreement and say that the main features of the phenomenon can be described in terms of classical trajectories which are solutions of Newton's equation in complex time. The probability of tunneling is governed by analytical properties of a time-dependent perturbation and the classical trajectory in the plane of complex time. Some preliminary numerical calculations of Euclidean resonance (an easy penetration through a classical nonstationary barrier due to an underbarrier interference) are presented

  9. Systems study on engineered barriers: barrier performance analysis

    International Nuclear Information System (INIS)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed

  10. Systems study on engineered barriers: barrier performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  11. The biofiltration permeable reactive barrier: Practical experience from Synthesia

    Energy Technology Data Exchange (ETDEWEB)

    Vesela, L.; Nemecek, J.; Siglova, M.; Kubal, M. [DEKONTA, Prague (Czech Republic)

    2006-10-15

    The paper refers to utilization of biological elements within permeable reactive barriers. The concept of a biofiltration permeable barrier has been tested in the laboratory and in pilot-scale. Oxyhumolite (oxidized young lignite) was examined as an absorption material and a biofilm carrier. Laboratory tests performed before the pilot verification confirmed that oxyhumolite adsorbs organic pollutants at a minimum value, but that it can be used for biofilm attachment. An experimental barrier was built on premises of a chemical factory contaminated mainly by various organic pollutants (benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorobenzenes, naphthalene, nitro-derivatives, phenols, trichloroethylene (TCE), and total petroleum hydrocarbon (TPH)). Before the barrier was installed, a preliminary survey of the unsaturated zone, hydrogeological investigation, and a microbiological survey had been performed. The barrier was designed as a trench-and-gate system with an in situ bioreactor. During the year 2004, measurements of groundwater flux and retention time under current hydrological conditions, together with chemical and microbiological monitoring, were carried out on the site. The results showed high effectiveness of organic contamination removal. Average elimination varied from 57.3% (naphthalene) to 99.9% (nitro-derivatives, BTEX); microbial density in the bioreactor was approx. 10{sup 5} CFU mL{sup -1}.

  12. Barriers associated with reduced physical activity in COPD patients

    Directory of Open Access Journals (Sweden)

    Priscila Batista Amorim

    2014-10-01

    Full Text Available OBJECTIVE: To evaluate the ability of COPD patients to perform activities of daily living (ADL; to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT, and an ADL limitation score. METHODS: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. RESULTS: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001, as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001. The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. CONCLUSIONS: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

  13. The relative importance of patient-reported barriers to colorectal cancer screening.

    Science.gov (United States)

    Jones, Resa M; Woolf, Steven H; Cunningham, Tina D; Johnson, Robert E; Krist, Alex H; Rothemich, Stephen F; Vernon, Sally W

    2010-05-01

    Colorectal cancer (CRC) screening rates are suboptimal. The most important barriers identified by patients are poorly understood. A comprehensive assessment of barriers to all recommended modalities is needed. In 2007, a questionnaire was mailed to 6100 patients, aged 50-75 years, from 12 family medicine practices in the Virginia Ambulatory Care Outcomes Research Network. People aged 65-75 years and African Americans were oversampled. Patients were asked to rate 19-21 barriers to each of four recommended tests. In 2008, responses were coded on a 5-point scale; higher scores reflected stronger barrier endorsement. The response rate was 55% (n=3357). Approximately 40% of respondents were aged >/=65 years, 30% were African-American, and 73% were adherent to screening. A clinician's failure to suggest screening and not knowing testing was necessary received the highest mean scores as barriers. Financial concerns and misconceptions were also cited. Barrier scores differed depending on whether respondents were never screened, overdue for screening, or adherent to guidelines. The top five barriers for each modality included test-specific barriers (e.g., handling stool, bowel preparation), which often outranked generic barriers to screening. Not knowing testing was necessary was a top barrier for all tests but colonoscopy. Although physician advice and awareness of the need for screening are important, barriers to screening are not homogenous across tests, and test-specific barriers warrant consideration in designing strategies to improve screening rates. Barrier scores differ by screening status, highlighting the need to address prior screening experience. Evidence that patients are more familiar with colonoscopy than with other modalities suggests an opportunity to improve screening rates by educating patients about alternative tests. 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Structure information from fusion barriers

    Indian Academy of Sciences (India)

    Pb, using the coupled reaction channel (CRC) method and correct structure information, have been analysed. The barrier distributions derived from these excitation functions including many of the significant channels are featureless, although these channels have considerable effects on the fusion excitation function.

  15. Communication Barriers in Distance Education

    Science.gov (United States)

    Isman, Aytekin; Dabaj, Fahme; Altinay, Fahriye; Altinay, Zehra

    2003-01-01

    Communication is a key concept as being the major tool for people in order to satisfy their needs. It is an activity which refers as process and effective communication requires qualified communication with the elimination of communication barriers. As it is known, distance education is a new trend by following contemporary facilities and tools…

  16. Functional barriers: Properties and evaluation

    NARCIS (Netherlands)

    Feigenbaum, A.; Dole, P.; Aucejo, S.; Dainelli, D.; Cruz Garcia, C. de la; Hankemeier, T.; N'Gono, Y.; Papaspyrides, C.D.; Paseiro, P.; Pastorelli, S.; Pavlidou, S.; Pennarun, P.Y.; Saillard, P.; Vidal, L.; Vitrac, O.; Voulzatis, Y.

    2005-01-01

    Functional barriers are multilayer structures deemed to prevent migration of some chemicals released by food-contact materials into food. In the area of plastics packaging, different migration behaviours of mono- and multilayer structures are assessed in terms of lag time and of their influence of

  17. Overcoming Barriers: Women in Superintendency

    Science.gov (United States)

    Miller, Claire M.

    2009-01-01

    Women currently represent the largest number of teachers in the United States but remain underrepresented in the superintendent position. This suggests that the superintendency has been influenced by patriarchy. If women are to break through the barriers that prevent them from attaining a superintendency, we will need to understand the social…

  18. Seasonal breaching of coastal barriers

    NARCIS (Netherlands)

    Tuan, Thieu Quang

    2007-01-01

    Natural or unintended breaching can be catastrophic, causing loss of human lives and damage to infrastructures, buildings and natural habitats. Quantitative understand-ing of coastal barrier breaching is therefore of great importance to vulnerability as-sessment of protection works as well as to

  19. Injectable barriers for waste isolation

    International Nuclear Information System (INIS)

    Persoff, P.; Finsterle, S.; Moridis, G.J.; Apps, J.; Pruess, K.; Muller, S.J.

    1995-03-01

    In this paper the authors report laboratory work and numerical simulation done in support of development and demonstration of injectable barriers formed from either of two fluids: colloidal silica or polysiloxane. Two principal problems addressed here are control of gel time and control of plume emplacement in the vadose zone. Gel time must be controlled so that the viscosity of the barrier fluid remains low long enough to inject the barrier, but increases soon enough to gel the barrier in place. During injection, the viscosity must be low enough to avoid high injection pressures which could uplift or fracture the formation. To test the grout gel time in the soil, the injection pressure was monitored as grouts were injected into sandpacks. When grout is injected into the vadose zone, it slumps under the influence of gravity, and redistributes due to capillary forces as it gels. The authors have developed a new module for the reservoir simulator TOUGH2 to model grout injection into the vadose zone, taking into account the increase of liquid viscosity as a function of gel concentration and time. They have also developed a model to calculate soil properties after complete solidification of the grout. The numerical model has been used to design and analyze laboratory experiments and field pilot tests. The authors present the results of computer simulations of grout injection, redistribution, and solidification

  20. Emergency nurses' knowledge of perceived barriers in pain management in Taiwan.

    Science.gov (United States)

    Tsai, Feng-Ching; Tsai, Yun-Fang; Chien, Chih-Cheng; Lin, Chia-Chin

    2007-11-01

    To explore knowledge of and perceived barriers to pain management among emergency nurses in Taiwan. Pain is the most common patient complaint in emergency departments. Quality care of these patients depends on the pain knowledge and pain management skills of emergency nurses. However, no studies have explored emergency nurses' knowledge of and perceived barriers to pain management in Taiwan. Nurse subjects (n = 249) were recruited from nine hospitals chosen by stratified sampling across Taiwan. Data were collected using the Nurses' Knowledge and Attitudes Survey-Taiwanese version, a scale to assess perceived barriers to pain management and a background information form. The overall average correct response rate for the knowledge scale was 49.2%, with a range of 4.8-89.2% for each survey question. The top barrier to managing pain was identified by these nurses as 'the responsibility of caring for other acutely ill patients in addition to a patient with pain. Knowledge of pain management had a significant, negative relationship with perceived barriers to pain management and a significant, positive relationship with extent of clinical care experience and total hours of prior pain management education. In addition, scores for knowledge and perceived barriers differed significantly by the nursing clinical ladder. Perceived barriers also differed significantly by hospital accreditation category. Our results indicate an urgent need to strengthen pain education for emergency nurses in Taiwan. The pain education should target knowledge deficits and barriers to changing pain management approaches for Taiwanese emergency nurses.

  1. Understanding energy efficiency barriers in Ukraine: Insights from a survey of commercial and industrial firms

    International Nuclear Information System (INIS)

    Timilsina, Govinda R.; Hochman, Gal; Fedets, Iryna

    2016-01-01

    Improvement of energy efficiency is an important element of energy policy for a sustainable supply of energy in Ukraine. However, the country is facing several challenges to the large-scale deployment of energy efficient technologies. We conducted a two-stage quota sample survey of 509 commercial and industrial firms of all regions of Ukraine to understand the barriers to energy efficiency improvements. Our study finds that more than two-thirds of the commercial and industrial firms in the country view improvement of energy efficiency very important to their business. However, due to several barriers they are unable to realize the improvements of energy efficiency. Among the 19 potential barriers investigated in the study, the survey results show that high upfront investment requirement, lack of government policies to support energy efficiency improvements, higher cost of capital, and lack of information and awareness are the most critical barriers to the improvement of energy efficiency in the industrial and commercial sectors in Ukraine. - Highlights: • Despite attractiveness, large scale deployment of energy efficiency is lacking. • Several barriers are responsible for slow implementation of energy efficiency. • Understanding the barriers from the field is crucial to design effective policies. • A survey of commercial and industrial firms reveals the key barriers. • Financial barriers are the main hurdles to adopt energy efficient technologies.

  2. Scale Pretesting

    Science.gov (United States)

    Howard, Matt C.

    2018-01-01

    Scale pretests analyze the suitability of individual scale items for further analysis, whether through judging their face validity, wording concerns, and/or other aspects. The current article reviews scale pretests, separated by qualitative and quantitative methods, in order to identify the differences, similarities, and even existence of the…

  3. Perceived barriers to effective job performance among nursing assistants in long-term care.

    Science.gov (United States)

    Parmelee, Patricia A; Laszlo, Mary C; Taylor, Jo A

    2009-10-01

    This research explored perceived barriers to job performance among a national sample of nursing assistants (NAs). Specific objectives were (1) to clarify which of the problems identified by previous research are most troublesome for NAs, (2) to develop a reliable quantitative measure of perceived barriers to job performance, and (3) to test construct validity of the measure vis-à-vis work-related psychological empowerment and job satisfaction. Nursing assistants attending the 2006 national conference of the National Association of Health Care Assistants completed a paper-and-pencil survey including 33 barriers to job performance and standardized measures of empowerment and job satisfaction. The barriers were also rated by a small sample of NAs at a single Georgia nursing home. Factor analysis of barriers items yielded a 30-item Nursing Assistants Barriers Scale (NABS) comprising 6 subscales: Teamwork, Exclusion, Respect, Workload, Work Stress, and New NAs. Lack of teamwork and exclusion from communication processes were rated as most problematic by both samples. The 6 NABS subscales were significantly and independently associated with empowerment and satisfaction; different barriers predicted the 2 constructs. This study is a first step toward quantitative assessment of NAs' perceptions of barriers to doing their jobs. Primary limitations are the select sample and use of a job satisfaction measure that may have artificially inflated correlations with the NABS. Nonetheless, results confirm the validity of the new scale as an operationalization of the barriers construct. The concept of barriers to job performance is a unique construct from work empowerment and satisfaction with one's job. Nursing assistants clearly differentiate various barriers, converging on workload and lack of teamwork as most problematic. Further work is needed to substantiate validity and reliability of the NABS, particularly with respect to NAs' actual job performance, intent to stay on the

  4. Space charge effects and coherent stability limits in barrier buckets

    Directory of Open Access Journals (Sweden)

    Oliver Boine-Frankenheim

    2003-03-01

    Full Text Available A large-scale Vlasov simulation study of the microwave instability below transition energy in a beam confined between two barrier pulses is performed. Starting from a matched distribution function for the confined ion beam including the space charge impedance the stability threshold in the longitudinal impedance plane is obtained. A simple stability criterium is found to be in good agreement with the simulation results.

  5. Exploring the communication barriers in private commercial banks of Bangladesh

    OpenAIRE

    Sultana, Nahneen; Abdullah, Abu Md.; Tabassum, Ayesha

    2013-01-01

    In Bangladesh, lots of private commercial banks are contributing for economic growth. The performance of the banks depends on a well-structured communication system. So by maintaining an effective communication system, the banks can gain competitive advantage. Thus the study aims to investigate the communication barriers that should be removed for effective communication in the private commercial banks of Bangladesh. A structured questionnaire survey based on 5-point Likert-scale was conducte...

  6. Internal transport barrier physics for steady state operation in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Wakatani, Masahiro [Kyoto Univ., Graduate School of Engineering, Uji, Kyoto (Japan); Fukuda, Takeshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Connor, Jack W. [Culham Science Centre, EURATOM/UKAEA Association (United Kingdom); Garbet, Xavier [Culham Science Centre, EFDA-JET CSU (United Kingdom); Gormezano, Claude [Associazone EURATOM-ENEA sulla Fusione C.R. Frascati (Italy); Mukhovatov, Vladimir [ITER Naka Joint Work Site, ITER Physics Unit, Naka, Ibaraki (Japan)

    2003-07-01

    Experimental results for the ITB (Internal Transport Barrier) formation and sustainment are compiled in a unified manner to find common features of ITBs in tokamaks. Global scaling laws for threshold power to obtain the ITBs are discussed. Theoretical models for plasmas with ITBs are summarized from stability and transport point of view. Finally possibility to obtain steady-state ITBs will be discussed in addition to extrapolation to ITER. (author)

  7. Energy Barriers and Hysteresis in Martensitic Phase Transformations

    Science.gov (United States)

    2008-08-01

    glacial acetic acid (CH3COOH) and 10-15% perchloric acid (HCLO4) by volume, the cathode was stainless steel , the anode was stainless steel or Ti, the...Submitted to Acta Materialia Energy barriers and hysteresis in martensitic phase transformations Zhiyong Zhang, Richard D. James and Stefan Müller...hysteresis based on the growth from a small scale of fully developed austenite martensite needles. In this theory the energy of the transition layer plays a

  8. Development of Permeable Reactive Barriers (PRB) Using Edible Oils

    Science.gov (United States)

    2008-06-01

    naturally occurring processes of advection and dispersion to bring the contaminants to the treatment barrier. A large scale approach would be to form a...process has been developed for distributing soybean oil as an oil-in-water emulsion consisting of small oil droplets dispersed in a continuous...Thiele Kaolin Company, Sandersville, Georgia) was added to certain materials to evaluate the effect of increasing clay content. Grain size

  9. Barriers to improvements in energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A.K.N.

    1991-10-01

    To promote energy-efficiency improvements, actions may be required at one or more levels -- from the lowest level of the consumer (residential, commercial, industrial, etc.) through the highest level of the global agencies. But barriers to the implementation of energy-efficiency improvements exist or can arise at all these levels. Taking up each one of these barriers in turn, the paper discusses specific measures that can contribute to overcoming the barriers. However, a one-barrier-one-measure approach must be avoided. Single barriers may in fact involve several sub-barriers. Also, combinations of measures are much more effective in overcoming barriers. In particular, combinations of measures that simultaneously overcome several barriers are most successful. The paper discusses the typology of barriers, explores their origin and suggests measures that by themselves or in combination with other measures, will overcome these barriers. Since most of the barriers dealt with can be found in the barriers'' literature, any originality in the paper lies in its systematic organization, synoptic view and holistic treatment of this issue. This paper is intended to initiate a comprehensive treatment of barriers, their origins and the measures that contribute to overcoming them. Hopefully, such a treatment will facilitate the implementation of energy-efficiency improvements involving a wide diversity of ever-changing energy end uses and consumer preferences.

  10. Barriers to improvements in energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A.K.N.

    1991-10-01

    To promote energy-efficiency improvements, actions may be required at one or more levels -- from the lowest level of the consumer (residential, commercial, industrial, etc.) through the highest level of the global agencies. But barriers to the implementation of energy-efficiency improvements exist or can arise at all these levels. Taking up each one of these barriers in turn, the paper discusses specific measures that can contribute to overcoming the barriers. However, a one-barrier-one-measure approach must be avoided. Single barriers may in fact involve several sub-barriers. Also, combinations of measures are much more effective in overcoming barriers. In particular, combinations of measures that simultaneously overcome several barriers are most successful. The paper discusses the typology of barriers, explores their origin and suggests measures that by themselves or in combination with other measures, will overcome these barriers. Since most of the barriers dealt with can be found in the ``barriers`` literature, any originality in the paper lies in its systematic organization, synoptic view and holistic treatment of this issue. This paper is intended to initiate a comprehensive treatment of barriers, their origins and the measures that contribute to overcoming them. Hopefully, such a treatment will facilitate the implementation of energy-efficiency improvements involving a wide diversity of ever-changing energy end uses and consumer preferences.

  11. Design and performance evaluation of a 1000-year evapotranspiration-capillary surface barrier

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuanfang Fred; Strickland, Christopher E.; Link, Steven O.

    2017-02-01

    Surface barrier technology is used to isolate radioactive waste and to reduce or eliminate recharge water to the waste zone for 1000 years or longer. However, the design and evaluation of such a barrier is challenging because of the extremely long design life. The Prototype Hanford Barrier (PHB) was designed as a 1000-year barrier with pre-determined design and performance objectives and demonstrated in field from 1994 to present. The barrier was tested to evaluate surface-barrier design and performance at the field scale under conditions of enhanced and natural precipitation and of no vegetation. The monitoring data demonstrate that the barrier satisfied nearly all key objectives. The PHB far exceeded the Resource Conservation and Recovery Act criteria, functioned in Hanford’s semiarid climate, limited drainage to well below the 0.5 mm yr-1 performance criterion, limited runoff, and minimized erosion. Given the two-decade record of successful performance and consideration of all the processes and mechanisms that could degrade the stability and hydrology in the future, the results suggest the PHB is very likely to perform for its 1000-year design life. This conclusion is based on two assumptions: (1) the exposed subgrade receives protection against erosion and (2) institutional controls prevent inadvertent human activity at the barrier. The PHB design can serve as the base for site-specific barriers over waste sites containing underground nuclear waste, uranium mine tailings, and hazardous mine waste.

  12. Patient-related barriers to pain management: the Barriers Questionnaire II (BQ-II).

    Science.gov (United States)

    Gunnarsdottir, Sigridur; Donovan, Heidi S; Serlin, Ronald C; Voge, Catherine; Ward, Sandra

    2002-10-01

    Patients' beliefs can act as barriers to optimal management of cancer pain. The Barriers Questionnaire (BQ) is a tool used to evaluate such barriers. Here, the BQ has been revised to reflect changes in pain management practices, resulting in the Barriers Questionnaire-II (BQ-II), a 27-item, self report instrument. This paper presents the results from two studies where the psychometric properties of the BQ-II were evaluated. In the first study, the responses of 27 nurses trained in pain management were compared to responses of a convenience sample of 12 patients with cancer. The results indicated that patients with cancer had higher mean scores on the BQ-II than did nurses trained in pain management. In the second study, a convenience sample of 172 patients with cancer responded to the BQ-II and a set of pain and quality of life (QOL) measures. A factor analysis supported four factors. Factor one, physiological effects, consists of 12 items addressing the beliefs that side effects of analgesics are inevitable and unmanageable, concerns about tolerance, and concerns about not being able to monitor changes in one's body when taking strong pain medications. Factor two, Fatalism, consists of three items addressing fatalistic beliefs about cancer pain and its management. Factor three, Communication, consists of six items addressing the concern that reports of pain distract the physician from treating the underlying disease, and the belief that 'good' patients do not complain of pain. The fourth and final factor, harmful effects, consists of six items addressing fear of becoming addicted to pain medication and the belief that pain medications harm the immune system. The BQ-II total had an internal consistency of 0.89, and alpha for the subscales ranged from 0.75 to 0.85. Mean (SD) scores on the total scale was 1.52 (0.73). BQ-II scores were related to measures of pain intensity and duration, mood, and QOL. Patients who used adequate analgesics for their levels of pain had

  13. Development of a cement-polymer close-coupled subsurface barrier technology

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, B.P. [Sandia National Labs., Albuquerque, NM (United States); Heiser, J. [Brookhaven National Lab., Upton, NY (United States); Stewart, W.; Phillips, S. [Applied Geotechnical Engineering and Construction, Inc., Richland, WA (United States)

    1997-02-01

    The primary objective of this project was to further develop close-coupled barrier technology for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional cement grout curtain followed by a thin inner lining of a polymer grout. The resultant barrier is a cement polymer composite that has economic benefits derived from the cement and performance benefits from the durable and chemically resistant polymer layer. The technology has matured from a regulatory investigation of issues concerning barriers and barrier materials to a pilot-scale, multiple individual column injections at Sandia National Labs (SNL) to full scale demonstration. The feasibility of this barrier concept was successfully proven in a full scale ``cold site`` demonstration at Hanford, WA. Consequently, a full scale deployment of the technology was conducted at an actual environmental restoration site at Brookhaven National Lab (BNL), Long Island, NY. This paper discusses the installation and performance of a technology deployment implemented at OU-1 an Environmental Restoration Site located at BNL.

  14. Development of a cement-polymer close-coupled subsurface barrier technology

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Heiser, J.; Stewart, W.; Phillips, S.

    1997-01-01

    The primary objective of this project was to further develop close-coupled barrier technology for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional cement grout curtain followed by a thin inner lining of a polymer grout. The resultant barrier is a cement polymer composite that has economic benefits derived from the cement and performance benefits from the durable and chemically resistant polymer layer. The technology has matured from a regulatory investigation of issues concerning barriers and barrier materials to a pilot-scale, multiple individual column injections at Sandia National Labs (SNL) to full scale demonstration. The feasibility of this barrier concept was successfully proven in a full scale ''cold site'' demonstration at Hanford, WA. Consequently, a full scale deployment of the technology was conducted at an actual environmental restoration site at Brookhaven National Lab (BNL), Long Island, NY. This paper discusses the installation and performance of a technology deployment implemented at OU-1 an Environmental Restoration Site located at BNL

  15. Prototype Hanford Surface Barrier: Design basis document

    International Nuclear Information System (INIS)

    Myers, D.R.; Duranceau, D.A.

    1994-11-01

    The Hanford Site Surface Barrier Development Program (BDP) was organized in 1985 to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site and other arid sites. This document provides the basis of the prototype barrier. Engineers and scientists have momentarily frozen evolving barrier designs and incorporated the latest findings from BDP tasks. The design and construction of the prototype barrier has required that all of the various components of the barrier be brought together into an integrated system. This integration is particularly important because some of the components of the protective barreir have been developed independently of other barreir components. This document serves as the baseline by which future modifications or other barrier designs can be compared. Also, this document contains the minutes of meeting convened during the definitive design process in which critical decisions affecting the prototype barrier's design were made and the construction drawings

  16. Highway renewable energy : photovoltaic noise barriers

    Science.gov (United States)

    2017-07-01

    Highway photovoltaic noise barriers (PVNBs) represent the combination of noise barrier systems and photovoltaic systems in order to mitigate traffic noise while simultaneously producing renewable energy. First deployed in Switzerland in 1989, PVNBs a...

  17. Physical Environmental Barriers to School Attendance among ...

    African Journals Online (AJOL)

    environment were the major barriers to school attendance. Conclusion: To ... Key words: Parents/caregivers, children with disabilities, barriers. Introduction .... It is not safe to walk ... feeling, learning, behaviour, and fits or convulsions. [19] The ...

  18. Students' Perceptions of Edmodo and Mobile Learning and Their Real Barriers towards Them

    Science.gov (United States)

    Al-Said, Khaleel M.

    2015-01-01

    The present research aims to investigate the students' perceptions levels of Edmodo and Mobile learning and to identify the real barriers of them at Taibah University in KSA. After implemented Edmodo application as an Mlearning platform, two scales were applied on the research sample, the first scale consisted of 36 statements was constructed to…

  19. Response of wave-dominated and mixed-energy barriers to storms

    NARCIS (Netherlands)

    Masselink, G.; Heteren, S. van

    2014-01-01

    Wave-dominated and mixed-energy barriers are extremely dynamic landforms, responding to processes operating over a spectrum of time scales, ranging from daily-to-monthly fluctuations related to storm and post-storm conditions, to century-to-millennium-scale evolution driven by relative sea-level

  20. Engineered passive bioreactive barriers: risk-managing the legacy of industrial soil and groundwater pollution.

    Science.gov (United States)

    Kalin, Robert M

    2004-06-01

    Permeable reactive barriers are a technology that is one decade old, with most full-scale applications based on abiotic mechanisms. Though there is extensive literature on engineered bioreactors, natural biodegradation potential, and in situ remediation, it is only recently that engineered passive bioreactive barrier technology is being considered at the commercial scale to manage contaminated soil and groundwater risks. Recent full-scale studies are providing the scientific confidence in our understanding of coupled microbial (and genetic), hydrogeologic, and geochemical processes in this approach and have highlighted the need to further integrate engineering and science tools.

  1. Recruitment barriers in a randomized controlled trial from the physicians' perspective – A postal survey

    Directory of Open Access Journals (Sweden)

    Karrer Werner

    2009-03-01

    Full Text Available Abstract Background The feasibility of randomized trials often depends on successful patient recruitment. Although numerous recruitment barriers have been identified it is unclear which of them complicate recruitment most. Also, most surveys have focused on the patients' perspective of recruitment barriers whereas the perspective of recruiting physicians has received less attention. Therefore, our aim was to conduct a postal survey among recruiting physicians of a multi-center trial to weigh barriers according to their impact on recruitment. Methods We identified any potential recruitment barriers from the literature and from our own experience with a multi-center trial of respiratory rehabilitation in patients with chronic obstructive pulmonary disease. We developed and pilot-tested a self-administered questionnaire where recruiting physicians were asked to express their agreement with statements about recruitment barriers on a Likert-type scale from 1 (full agreement with statement = very substantial recruitment barrier to 7 (no agreement with statement = no recruitment barrier. Results 38 of 55 recruiting physicians returned questionnaires (69% response rate, of which 35 could be analyzed (64% useable response rate. Recruiting physicians reported that "time constraints" (median agreement of 3, interquartile range 2–5 had the most negative impact on recruitment followed by "difficulties including identified eligible patients" (median agreement of 5, IQR 3–6. Other barriers such as "trial design barriers", "lack of access to treatment", "individual barriers of recruiting physicians" or "insufficient training of recruiting physicians" were perceived to have little or no impact on patient recruitment. Conclusion Physicians perceived time constraints as the most relevant recruitment barrier in a randomized trial. To overcome recruitment barriers interventions, that are affordable for both industry- and investigator-driven trials, need to be

  2. Regulatory analysis for the use of underground barriers at the Hanford Site tank farms

    International Nuclear Information System (INIS)

    Hampsten, K.L.

    1994-01-01

    Sixty-seven of the single-shell tanks at the Hanford Site, Richland, Washington, are assumed to have leaked in the past. Some of the waste retrieval options being considered, such as past-practice sluicing (a process that uses hot water to dislodge waste for subsequent removal by pumping), have the potential for increasing releases of dangerous waste from these tanks. Underground barrier systems are being evaluated as a method to mitigate releases of tank waste to the soil and groundwater that may occur during retrieval activities. The following underground barrier system options are among those being evaluated to determine whether their construction at the Single-Shell Tank Farms is viable. (1) A desiccant barrier would be created by circulating air through the subsurface soil to lower and then maintain the water saturation below the levels required for liquids to flow. (2) An injected materials barrier would be created by injecting materials such as grout or silica into the subsurface soils to form a barrier around and under a given tank or tank farm. (3) A cryogenic barrier would be created by freezing subsurface soils in the vicinity of a tank or tank farm. An analysis is provided of the major regulatory requirements that may impact full scale construction and operation of an underground barrier system and a discussion of factors that should be considered throughout the barrier selection process, irrespective of the type of underground barrier system being considered. However, specific barrier systems will be identified when a given regulation will have significant impact on a particular type of barrier technology. Appendix A provides a matrix of requirements applicable to construction and operation of an underground barrier system

  3. Addressing barriers to low carbon energy

    International Nuclear Information System (INIS)

    Berry, Fiona; Dunstan, Chris

    2012-01-01

    , for any generated electricity exported to the grid the university would only be paid a low wholesale energy rate and possibly a part of the avoided transmission charges but would be required to pay much higher retail rates for importing electricity. To save money, avoiding connection or off-grid generation) would mean reducing the size of the trigeneration to match baseload demand in each individual building, a much less efficient process which would not achieve the large carbon reductions targets required. Because of these constraints at an individual building scale, the university began thinking beyond the building, to precinct scale trigeneration across multiple buildings. It would involve multiple buildings linking their trigeneration units to avoid duplicating infrastructure and provide larger scale, more efficient supply and more significant emissions reductions. The 'unlocking barriers to cogeneration' project undertaken by The Property Council of Australia, Climate Works Australia and Seed Advisory sought to overcome the barrier of time and fees under current regulation through amendments to the National Electricity Rules. The current rules allow streamlined connection time for 'micro-scale' embedded generators for households (10 kilowatts) and small businesses (24kW) but not for grid connection between 24kW and 30MW. Consequently, building owners ready to install cogeneration can face significant delays from negotiation requirements, with holding costs of $50,000 to $70,000 per week. Following research and engagement with electricity distribution network businesses and cogeneration proponents, the PCA-Climateworks project team proposed amendments to the AS4777 standard which would extend the automatic right of connection to small to medium generators. A rule change submission was put forward to the Australian Energy Market Commission in April 2012 and it responded by issuing a paper on June 14 to facilitate public consultation on the proposal. It is expected

  4. Security barriers with automated reconnaissance

    Science.gov (United States)

    McLaughlin, James O; Baird, Adam D; Tullis, Barclay J; Nolte, Roger Allen

    2015-04-07

    An intrusion delaying barrier includes primary and secondary physical structures and can be instrumented with multiple sensors incorporated into an electronic monitoring and alarm system. Such an instrumented intrusion delaying barrier may be used as a perimeter intrusion defense and assessment system (PIDAS). Problems with not providing effective delay to breaches by intentional intruders and/or terrorists who would otherwise evade detection are solved by attaching the secondary structures to the primary structure, and attaching at least some of the sensors to the secondary structures. By having multiple sensors of various types physically interconnected serves to enable sensors on different parts of the overall structure to respond to common disturbances and thereby provide effective corroboration that a disturbance is not merely a nuisance or false alarm. Use of a machine learning network such as a neural network exploits such corroboration.

  5. Application of polycrystalline diffusion barriers

    International Nuclear Information System (INIS)

    Tsymbal, V.A.; Kolupaev, I.N.

    2010-01-01

    Degradation of contacts of the electronic equipment at the raised temperatures is connected with active diffusion redistribution of components contact - metalized systems (CMS) and phase production on interphase borders. One of systems diffusion barriers (DB) are polycrystalline silicide a film, in particular silicides of the titan. Reception disilicide the titan (TiSi 2 ) which on the parameters is demanded for conditions of microelectronics from known silicides of system Ti-Si, is possible as a result of direct reaction of a film of the titan and a substrate of silicon, and at sedimentation of layer Ti-Si demanded stoichiometric structure. Simultaneously there is specific problem polycrystalline diffusion a barrier (PDB): the polycrystalline provides structural balance and metastability film disilicide, but leaves in it borders of grains - easy local ways of diffusion. In clause the analysis diffusion permeability polycrystalline and polyphase DB is made and recommendations for practical methods of increase of blocking properties PDB are made.

  6. Barriers in implementing research among registered nurses working in the care of the elderly: a multicenter study in Spain.

    Science.gov (United States)

    Sarabia-Cobo, C M; Sarabia-Cobo, A B; Pérez, V; Hermosilla, C; Nuñez, M J; de Lorena, P

    2015-11-01

    This study identified barriers to the utilization of research results perceived by nurses who work in nursing homes in Spain. An observational, cross-sectional, descriptive, and multicentre study was conducted in 126 nursing homes in different Spanish cities. The BARRIERS to Research Utilization Scale (BARRIERS scale) was used to identify barriers. A total of 756 nurses responded (92.48%). BARRIERS scale variables with the highest scores included Characteristics of the organization (mean=24.89, SD=4.37), followed by Professional features (mean=21.87, SD=4.85). The specific barriers that were rated the highest included "not enough time on the job to implement new ideas" (mean=3.89, SD=0.98), followed by "unknown nursing research" (mean=2.75; SD=1.22) and "Doctors do not cooperate in the implementation" (mean=3.01, SD=1.85). Geriatric nurses perceive time as the main barrier to implementing the results of research in practice. The number and nature of the barriers are consistent with studies from other countries. Knowledge of the barriers is crucial for institutions and educators to instigate measures that improve the implementation of nursing research, especially in an area like elderly care. To our knowledge, this is the first study conducted among geriatric nurses in Spain. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Scaling laws for coastal overwash morphology

    Science.gov (United States)

    Lazarus, Eli D.

    2016-12-01

    Overwash is a physical process of coastal sediment transport driven by storm events and is essential to landscape resilience in low-lying barrier environments. This work establishes a comprehensive set of scaling laws for overwash morphology: unifying quantitative descriptions with which to compare overwash features by their morphological attributes across case examples. Such scaling laws also help relate overwash features to other morphodynamic phenomena. Here morphometric data from a physical experiment are compared with data from natural examples of overwash features. The resulting scaling relationships indicate scale invariance spanning several orders of magnitude. Furthermore, these new relationships for overwash morphology align with classic scaling laws for fluvial drainages and alluvial fans.

  8. Verification of the integrity of barriers using gas diffusion

    International Nuclear Information System (INIS)

    Ward, D.B.; Williams, C.V.

    1997-06-01

    In-situ barrier materials and designs are being developed for containment of high risk contamination as an alternative to immediate removal or remediation. The intent of these designs is to prevent the movement of contaminants in either the liquid or vapor phase by long-term containment, essentially buying time until the contaminant depletes naturally or a remediation can be implemented. The integrity of the resultant soil-binder mixture is typically assessed by a number of destructive laboratory tests (leaching, compressive strength, mechanical stability with respect to wetting and freeze-thaw cycles) which as a group are used to infer the likelihood of favorable long-term performance of the barrier. The need exists for a minimally intrusive yet quantifiable methods for assessment of a barrier's integrity after emplacement, and monitoring of the barrier's performance over its lifetime. Here, the authors evaluate non-destructive measurements of inert-gas diffusion (specifically, SF 6 ) as an indicator of waste-form integrity. The goals of this project are to show that diffusivity can be measured in core samples of soil jet-grouted with Portland cement, validate the experimental method through measurements on samples, and to calculate aqueous diffusivities from a series of diffusion measurements. This study shows that it is practical to measure SF 6 diffusion rates in the laboratory on samples of grout (Portland cement and soil) typical of what might be used in a barrier. Diffusion of SF 6 through grout (Portland cement and soil) is at least an order of magnitude slower than through air. The use of this tracer should be sensitive to the presence of fractures, voids, or other discontinuities in the grout/soil structure. Field-scale measurements should be practical on time-scales of a few days

  9. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Garcia R, G.; Ordonez R, E.; Ordonez R, En.

    2002-01-01

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO 4 ) and the alpha zirconium hydrogen phosphate (Zr(HPO 4 ) 2H 2 O) starting from sea sand in an easy and economic way. (Author)

  10. Fission barriers of light nuclei

    International Nuclear Information System (INIS)

    Grotowski, K.; Planeta, R.; Blann, M.; Komoto, T.

    1989-01-01

    Experimental fission excitation functions for compound nuclei /sup 52/Fe, /sup 49/Cr, /sup 46/V, and /sup 44/Ti formed in heavy-ion reactions are analyzed in the Hauser-Feshbach/Bohr-Wheeler formalism using fission barriers based on the rotating liquid drop model of Cohen et al. and on the rotating finite range model of Sierk. We conclude that the rotating finite range approach gives better reproduction of experimental fission yields, consistent with results found for heavier systems

  11. Barriers to Physical Activity in East Harlem, New York

    Directory of Open Access Journals (Sweden)

    Ashley M. Fox

    2012-01-01

    Full Text Available Background. East Harlem is an epicenter of the intertwining epidemics of obesity and diabetes in New York. Physical activity is thought to prevent and control a number of chronic illnesses, including diabetes, both independently and through weight control. Using data from a survey collected on adult (age 18+ residents of East Harlem, this study evaluated whether perceptions of safety and community-identified barriers were associated with lower levels of physical activity in a diverse sample. Methods. We surveyed 300 adults in a 2-census tract area of East Harlem and took measurements of height and weight. Physical activity was measured in two ways: respondents were classified as having met the weekly recommended target of 2.5 hours of moderate physical activity (walking per week (or not and reporting having engaged in at least one recreational physical activity (or not. Perceived barriers were assessed through five items developed by a community advisory board and perceptions of neighborhood safety were measured through an adapted 7-item scale. Two multivariate logistic regression models with perceived barriers and concerns about neighborhood safety were modeled separately as predictors of engaging in recommended levels of exercise and recreational physical activity, controlling for respondent weight and sociodemographic characteristics. Results. The most commonly reported perceived barriers to physical activity identified by nearly half of the sample were being too tired or having little energy followed by pain with exertion and lack of time. Multivariate regression found that individuals who endorsed a greater number of perceived barriers were less likely to report having met their weekly recommended levels of physical activity and less likely to engage in recreational physical activity controlling for covariates. Concerns about neighborhood safety, though prevalent, were not associated with physical activity levels. Conclusions. Although

  12. Zirconium-barrier cladding attributes

    International Nuclear Information System (INIS)

    Rosenbaum, H.S.; Rand, R.A.; Tucker, R.P.; Cheng, B.; Adamson, R.B.; Davies, J.H.; Armijo, J.S.; Wisner, S.B.

    1987-01-01

    This metallurgical study of Zr-barrier fuel cladding evaluates the importance of three salient attributes: (1) metallurgical bond between the zirconium liner and the Zircaloy substrate, (2) liner thickness (roughly 10% of the total cladding wall), and (3) softness (purity). The effect that each of these attributes has on the pellet-cladding interaction (PCI) resistance of the Zr-barrier fuel was studied by a combination of analytical model calculations and laboratory experiments using an expanding mandrel technique. Each of the attributes is shown to contribute to PCI resistance. The effect of the zirconium liner on fuel behavior during off-normal events in which steam comes in contact with the zirconium surface was studied experimentally. Simulations of loss-of-coolant accident (LOCA) showed that the behavior of Zr-barrier cladding is virtually indistinguishable from that of conventional Zircaloy cladding. If steam contacts the zirconium liner surface through a cladding perforation and the fuel rod is operated under normal power conditions, the zirconium liner is oxidized more rapidly than is Zircaloy, but the oxidation rate returns to the rate of Zircaloy oxidation when the oxide phase reaches the zirconium-Zircaloy metallurgical bond

  13. Filamentary and diffuse barrier discharges

    International Nuclear Information System (INIS)

    Kogelschatz, U.

    2001-01-01

    Barrier discharges, sometimes also referred to as dielectric-barrier discharges or silent discharges, are characterized by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an ac power supply. The main advantage of this type of electrical discharge is, that non-equilibrium plasma conditions in atmospheric-pressure gases can be established in an economic and reliable way. This has led to a number of important applications including industrial ozone generation, surface modification of polymers, plasma chemical vapor deposition, excitation of CO 2 lasers, excimer lamps and, most recently, large-area flat plasma display panels. Depending on the application, the width of the discharge gap can range from less than 0.1 mm to about 100 mm and the applied frequency from below line frequency to several gigahertz. Typical materials used for the insulating layer (dielectric barrier) are glass, quartz, ceramics but also thin enamel or polymer layers

  14. Perceptions regarding strategic and structural entry barriers

    NARCIS (Netherlands)

    Lutz, C.H.M.; Kemp, R.G.M.; Dijkstra, S.G.

    2010-01-01

    This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on

  15. Perceptions regarding strategic and structural entry barriers

    NARCIS (Netherlands)

    Lutz, Clemens H. M.; Kemp, Ron G. M.; Dijkstra, S. Gerhard

    This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on

  16. Faculty Perceptions about Barriers to Active Learning

    Science.gov (United States)

    Michael, Joel

    2007-01-01

    Faculty may perceive many barriers to active learning in their classrooms. Four groups of participants in a faculty development workshop were asked to list their perceived barriers to active learning. Many of the problems identified were present on more than one list. The barriers fall into three categories: student characteristics, issues…

  17. Barriers to Mammography among Inadequately Screened Women

    Science.gov (United States)

    Stoll, Carolyn R. T.; Roberts, Summer; Cheng, Meng-Ru; Crayton, Eloise V.; Jackson, Sherrill; Politi, Mary C.

    2015-01-01

    Mammography use has increased over the past 20 years, yet more than 30% of women remain inadequately screened. Structural barriers can deter individuals from screening, however, cognitive, emotional, and communication barriers may also prevent mammography use. This study sought to identify the impact of number and type of barriers on mammography…

  18. Market barriers to welfare product innovations

    NARCIS (Netherlands)

    Binnekamp, M.H.A.; Ingenbleek, P.T.M.

    2006-01-01

    New products that are based on higher animal welfare standards encounter several barriers on the road to market acceptance. The authors focus on the Dutch poultry sector and distinguish between retailer and consumer barriers. Retailer barriers include the powerful position of retailers, the price

  19. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  20. Converse Theorems for Safety and Barrier Certificates

    OpenAIRE

    Ratschan, Stefan

    2017-01-01

    An important tool for proving safety of dynamical systems is the notion of a barrier certificate. In this paper we prove that every robustly safe ordinary differential equation has a barrier certificate. Moreover, we show a construction of such a barrier certificate based on a set of states that is reachable in finite time.

  1. Barriers to Quitting Smoking Among Substance Dependent Patients Predict Smoking Cessation Treatment Outcome.

    Science.gov (United States)

    Martin, Rosemarie A; Cassidy, Rachel N; Murphy, Cara M; Rohsenow, Damaris J

    2016-05-01

    For smokers with substance use disorders (SUD), perceived barriers to quitting smoking include concerns unique to effects on sobriety as well as usual concerns. We expanded our Barriers to Quitting Smoking in Substance Abuse Treatment (BQS-SAT) scale, added importance ratings, validated it, and then used the importance scores to predict smoking treatment response in smokers with substance use disorders (SUD) undergoing smoking treatment in residential treatment programs in two studies (n=184 and 340). Both components (general barriers, weight concerns) were replicated with excellent internal consistency reliability. Construct validity was supported by significant correlations with pretreatment nicotine dependence, smoking variables, smoking self-efficacy, and expected effects of smoking. General barriers significantly predicted 1-month smoking abstinence, frequency and heaviness, and 3-month smoking frequency; weight concerns predicted 1-month smoking frequency. Implications involve addressing barriers with corrective information in smoking treatment for smokers with SUD. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Barriers to Quitting Smoking among Substance Dependent Patients Predict Smoking Cessation Treatment Outcome

    Science.gov (United States)

    Martin, Rosemarie A.; Cassidy, Rachel; Murphy, Cara M.; Rohsenow, Damaris J.

    2016-01-01

    For smokers with substance use disorders (SUD), perceived barriers to quitting smoking include concerns unique to effects on sobriety as well as usual concerns. We expanded our Barriers to Quitting Smoking in Substance Abuse Treatment (BQS-SAT) scale, added importance ratings, validated it, and then used the importance scores to predict smoking treatment response in smokers with substance use disorders (SUD) undergoing smoking treatment in residential treatment programs in two studies (n = 184 and 340). Both components (General Barriers, Weight Concerns) were replicated with excellent internal consistency reliability. Construct validity was supported by significant correlations with pretreatment nicotine dependence, smoking variables, smoking self-efficacy, and expected effects of smoking. General Barriers significantly predicted 1-month smoking abstinence, frequency and heaviness, and 3-month smoking frequency; Weight Concerns predicted 1-month smoking frequency. Implications involve addressing barriers with corrective information in smoking treatment for smokers with SUD. PMID:26979552

  3. Can human activities alter the drowning fate of barrier islands?

    Science.gov (United States)

    Lorenzo-Trueba, J.; Ashton, A. D.; Jin, D.; Hoagland, P.; Kite-Powell, H.

    2012-12-01

    Low-lying coastal barriers face an uncertain future over the coming century and beyond as sea levels rise, with many projections suggesting end-of-century rates of sea-level rise as high or higher than 1 cm/yr. Geologically, such rates of sea-level rise have been experienced several thousand years ago and we can use our understanding of geological processes and sedimentary evidence to help unravel the dynamics of natural barriers experiencing sea-level rise. Along many modern coastal barriers, however, anthropic change, such as beach nourishment, dune construction, and emplacement of hard structures, plays a dominant role in coastline dynamics. A fundamental question to be addressed is whether human activities intended to preserve infrastructure and beach recreation may make wholesale collapse, or 'drowning,' of barrier systems more likely. Here we present a numerical modeling tool that couples natural processes and the human responses to these changes (and the subsequent of human responses on natural processes). Recent theoretical model development suggests that barriers are intrinsically morphodynamic features, responding to sea-level rise in complex ways through the interactions of marine processes and barrier overwash. Undeveloped coastal barriers would therefore respond to an accelerated sea-level rise in complex, less predictable manners than suggested by existing long-term models. We have developed a model that examines non-equilibrium cross-shore evolution of barrier systems at decadal to centennial temporal scales, focusing on the interactions between processes of shoreface evolution and overwash deposition. Model responses demonstrate two means of barrier collapse during sea-level rise: 'height drowning', which occurs when overwash fluxes are insufficient to maintain the landward migration rate required to keep in pace with sea-level rise, and 'width drowning', which occurs when the shoreface response is insufficient to maintain the barrier geometry

  4. Barriers to Effective Learning of High School Students in Turkey

    Directory of Open Access Journals (Sweden)

    Eda Gürlen

    2016-06-01

    Full Text Available This study aims to present the development and validation process of a scale to explore the learning barriers of high school students in Turkey. For this purpose, a scale was developed and administered to 316 high school students studying in the different counties of Ankara in the spring term of 2014-2015 academic year. Gathering the data, an exploratory factor analysis was run through SPSS Package program to see the structure of the interrelationships among the variables under six tests. Furthermore, a reliability analysis was conducted to the items under each test in the scale. As a result, one factor appeared under each test when the eigenvalues and variance percentages were examined, making six factors in total. The Cronbach’s Alpha Reliability Coefficient was calculated as to be significant for each test, which showed that the tests were reliable. Finally, some items were excluded from the scale.

  5. Cryogenic Barrier Demonstration Project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.A.; Yarmak, E.; Long, E.L.

    2000-03-01

    A long-term frozen soil barrier was implemented at the HRE (Homogeneous Reactor Experiment) Pond facility at the Oak Ridge National Laboratory in 1997. This was performed to verify the technical feasibility and costs of deploying a frozen barrier at a radiologically contaminated site. Work began in September 1996 and progressed through to December 1999. The frozen barrier has been operational since November 1997. Verification of the barrier integrity was performed independently by the EPA's SITE Program. This project showed frozen barriers offer a proven technology to retain below grade hazardous substances at relatively low costs with minimal effect on the environment.

  6. Barriers to Quitting Smoking among Substance Dependent Patients Predict Smoking Cessation Treatment Outcome

    OpenAIRE

    Martin, Rosemarie A.; Cassidy, Rachel; Murphy, Cara M.; Rohsenow, Damaris J.

    2016-01-01

    For smokers with substance use disorders (SUD), perceived barriers to quitting smoking include concerns unique to effects on sobriety as well as usual concerns. We expanded our Barriers to Quitting Smoking in Substance Abuse Treatment (BQS-SAT) scale, added importance ratings, validated it, and then used the importance scores to predict smoking treatment response in smokers with substance use disorders (SUD) undergoing smoking treatment in residential treatment programs in two studies (n = 18...

  7. Maslowian Scale.

    Science.gov (United States)

    Falk, C.; And Others

    The development of the Maslowian Scale, a method of revealing a picture of one's needs and concerns based on Abraham Maslow's levels of self-actualization, is described. This paper also explains how the scale is supported by the theories of L. Kohlberg, C. Rogers, and T. Rusk. After a literature search, a list of statements was generated…

  8. Control of BTEX migration using a biologically enhanced permeable barrier

    International Nuclear Information System (INIS)

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

    1997-01-01

    A permeable barrier system, consisting of a line of closely spaced wells, was installed perpendicular to ground water flow to control the migration of a dissolved hydrocarbon plume. The wells were charged with concrete briquets that release oxygen and nitrate at a controlled rate, enhancing aerobic biodegradation in the downgradient aquifer. Laboratory batch reactor experiments were conducted to identify concrete mixtures that slowly released oxygen over an extended time period. A full-scale permeable barrier system using ORC was constructed at a gasoline-spill site. During the first 242 days of operation, total BTEX decreased from 17 to 3.4 mg/L and dissolved oxygen increased from 0.4 to 1.8 mg/L during transport through the barrier. Over time, BTEX treatment efficiencies declined, indicating the barrier system had become less effective in releasing oxygen and nutrients to the highly contaminated portion of the aquifer. Point dilution tests and sediment analyses performed at the conclusion of the project indicated that the aquifer in the vicinity of the remediation wells had been clogged by precipitation with iron minerals

  9. On the performance of capillary barriers as landfill cover

    Directory of Open Access Journals (Sweden)

    M. Kämpf

    1997-01-01

    Full Text Available Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m. In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  10. On the performance of capillary barriers as landfill cover

    Science.gov (United States)

    Kämpf, M.; Montenegro, H.

    Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  11. Herbicides: A new threat to the Great Barrier Reef

    International Nuclear Information System (INIS)

    Lewis, Stephen E.; Brodie, Jon E.; Bainbridge, Zoe T.; Rohde, Ken W.; Davis, Aaron M.; Masters, Bronwyn L.; Maughan, Mirjam; Devlin, Michelle J.; Mueller, Jochen F.; Schaffelke, Britta

    2009-01-01

    The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. - Herbicide residues have been detected in Great Barrier Reef catchment waterways and river water plumes which may affect marine ecosystems.

  12. Factors predicting barriers to exercise in midlife Australian women.

    Science.gov (United States)

    McGuire, Amanda; Seib, Charrlotte; Anderson, Debra

    2016-05-01

    Chronic diseases are the leading cause of death and disability worldwide. They are, though, largely attributable to modifiable lifestyle risk factors, including lack of exercise. This study aims to investigate what factors predict perceptions of barriers to exercise in midlife women. This cross-sectional descriptive study collected data from midlife Australian women by online questionnaire. Volunteers aged between 40 and 65 years were recruited following media publicity about the study. The primary outcome measure was perceived exercise barriers (EBBS Barriers sub-scale). Other self-report data included: exercise, smoking, alcohol, fruit and vegetable consumption, body mass index, physical and mental health and well-being (MOS SF-12v2) and exercise self-efficacy. On average, the 225 participants were aged 50.9 years (SD=5.9). The significant predictors of perceived barriers to exercise were perceived benefits of exercise, exercise self-efficacy, physical well-being and mental well-being. These variables explained 41% of the variance in the final model (F (8219)=20.1, pexercise correlate with beliefs about the health benefits of exercise, exercise self-efficacy, physical and mental well-being. These findings have application to health promotion interventions targeting exercise behaviour change in midlife women. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh

    2014-11-24

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results demonstrate the suppression of perfect backscattering, while all other scattering processes, which do not entail a complete spin and momentum reversal, are allowed. Furthermore, we find that the spin of the surface state develops an out-of-plane component as it traverses the barrier. Our calculations reveal the existence of quasibound states in the vicinity of the surface barriers, which appear in the form of an enhanced density of states in the energy window corresponding to the topological state. For double barriers we demonstrate the formation of quantum well states. To complement our first-principles results we construct a two-dimensional low-energy effective model and illustrate its shortcomings. Our findings are discussed in the context of a number of recent experimental works.

  14. Using a Bayesian network to predict barrier island geomorphologic characteristics

    Science.gov (United States)

    Gutierrez, Ben; Plant, Nathaniel G.; Thieler, E. Robert; Turecek, Aaron

    2015-01-01

    Quantifying geomorphic variability of coastal environments is important for understanding and describing the vulnerability of coastal topography, infrastructure, and ecosystems to future storms and sea level rise. Here we use a Bayesian network (BN) to test the importance of multiple interactions between barrier island geomorphic variables. This approach models complex interactions and handles uncertainty, which is intrinsic to future sea level rise, storminess, or anthropogenic processes (e.g., beach nourishment and other forms of coastal management). The BN was developed and tested at Assateague Island, Maryland/Virginia, USA, a barrier island with sufficient geomorphic and temporal variability to evaluate our approach. We tested the ability to predict dune height, beach width, and beach height variables using inputs that included longer-term, larger-scale, or external variables (historical shoreline change rates, distances to inlets, barrier width, mean barrier elevation, and anthropogenic modification). Data sets from three different years spanning nearly a decade sampled substantial temporal variability and serve as a proxy for analysis of future conditions. We show that distinct geomorphic conditions are associated with different long-term shoreline change rates and that the most skillful predictions of dune height, beach width, and beach height depend on including multiple input variables simultaneously. The predictive relationships are robust to variations in the amount of input data and to variations in model complexity. The resulting model can be used to evaluate scenarios related to coastal management plans and/or future scenarios where shoreline change rates may differ from those observed historically.

  15. Mercury Oxidation via Catalytic Barrier Filters Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Seames; Michael Mann; Darrin Muggli; Jason Hrdlicka; Carol Horabik

    2007-09-30

    In 2004, the Department of Energy National Energy Technology Laboratory awarded the University of North Dakota a Phase II University Coal Research grant to explore the feasibility of using barrier filters coated with a catalyst to oxidize elemental mercury in coal combustion flue gas streams. Oxidized mercury is substantially easier to remove than elemental mercury. If successful, this technique has the potential to substantially reduce mercury control costs for those installations that already utilize baghouse barrier filters for particulate removal. Completed in 2004, Phase I of this project successfully met its objectives of screening and assessing the possible feasibility of using catalyst coated barrier filters for the oxidation of vapor phase elemental mercury in coal combustion generated flue gas streams. Completed in September 2007, Phase II of this project successfully met its three objectives. First, an effective coating method for a catalytic barrier filter was found. Second, the effects of a simulated flue gas on the catalysts in a bench-scale reactor were determined. Finally, the performance of the best catalyst was assessed using real flue gas generated by a 19 kW research combustor firing each of three separate coal types.

  16. Implementation of renewable energy technology - Opportunities and barriers. Summary of country studies

    Energy Technology Data Exchange (ETDEWEB)

    Painuly, J.P.; Fenhann, J.V.

    2002-07-01

    The project was launched to identify barriers to the implementation of renewable energy technologies (RETs) and explore measures to overcome the identified barriers. National institutions in Egypt, Ghana and Zimbabwe carried out the country studies based on the basic methodological framework provided by the UNEP Centre. The objectives of the project included strengthening institutional capacity for analysis and implementation of RET projects in the participating countries and bring out experiences on RETs barriers and removal measures for dissemination so that others can benefit from the knowledge so gained. An important highlight of the studies was involvement of stake holders in the process of identification of barriers and measures to remove them. A preliminary identification of relevant RETs for their countries was done by the country teams in the initial stage of the project. After that, national workshops involving various stake holders were held between July and September 1999 to discuss the RETs and barriers to their implementation. Based on the discussions, a few important RETs were identified for more detailed study. PV systems for rural electrification, solar water heating systems and large-scale biogas system were identified and analysed for barriers in the Egypt country study. Economic, information and policy barriers were identified as major barriers for these technologies. Solar water pumps, biogas and small hydro were the focus of study in Ghana. In this case also, economic, information and policy barriers were found to be the important barriers for the selected technologies. In the case of Zimbabwe, focus was on identification of primary and secondary barriers to RETs dissemination. The primary barriers included lack of capacity to develop proposals, lack of information for policy making and framework for information dissemination. The study concluded that the secondary barriers as seen and experienced by the stake holders are due to primary

  17. Nurses' knowledge and barriers regarding pain management in intensive care units.

    Science.gov (United States)

    Wang, Hsiang-Ling; Tsai, Yun-Fang

    2010-11-01

    To explore nurses' knowledge and barriers regarding pain management in intensive care units. Pain is a common and treatable condition among intensive care patients. Quality care of these patients depends on the pain knowledge and pain management skills of critical care nurses. However, no single study has explored these nurses' knowledge of and perceived barriers to pain management in Taiwan. A cross-sectional study. Intensive care unit nurses (n = 370) were recruited from 16 hospitals chosen by stratified sampling across Taipei County in Taiwan. Data were collected on nurses' knowledge of pain management using the Nurses' Knowledge and Attitudes Survey-Taiwanese version, on perceived barriers to pain management using a researcher-developed scale and on background information. The overall average correct response rate for the knowledge scale was 53.4%, indicating poor knowledge of pain management. The top barrier to managing pain identified by these nurses was 'giving proper pain prescription needs doctor's approval; can't depend on me'. Knowledge of pain management was significantly and negatively related to perceived barriers to pain management. In addition, scores for knowledge and perceived barriers differed significantly by specific intensive care unit. Knowledge also differed significantly by nurses' education level, clinical competence level (nursing ladder) and hospital accreditation category. Our results indicate an urgent need to strengthen pain education by including case analysis for intensive care nurses in Taiwan. Pain education should target knowledge deficits and barriers to changing pain management approaches for Taiwanese nurses in intensive care units. © 2010 Blackwell Publishing Ltd.

  18. Collaborative learning to unlock investments for functional ecological infrastructure: Bridging barriers in social-ecological systems in South Africa

    CSIR Research Space (South Africa)

    Angelstam, P

    2017-05-01

    Full Text Available . Based on expert knowledge at three scales, we analysed South Africa's opportunity to active adaptive management and to unlock investments that enhance functional ecological infrastructure. Barriers included lack of trust among actors, limited...

  19. Chemical barriers for controlling groundwater contamination

    International Nuclear Information System (INIS)

    Morrison, S.J.; Spangler, R.R.

    1993-01-01

    Chemical barriers are being explored as a low-cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts. 10 refs., 9 figs., 1 tab

  20. Exercise barriers self-efficacy: development and validation of a subcale for individuals with cancer-related lymphedema.

    Science.gov (United States)

    Buchan, Jena; Janda, Monika; Box, Robyn; Rogers, Laura; Hayes, Sandi

    2015-03-18

    No tool exists to measure self-efficacy for overcoming lymphedema-related exercise barriers in individuals with cancer-related lymphedema. However, an existing scale measures confidence to overcome general exercise barriers in cancer survivors. Therefore, the purpose of this study was to develop, validate and assess the reliability of a subscale, to be used in conjunction with the general barriers scale, for determining exercise barriers self-efficacy in individuals facing lymphedema-related exercise barriers. A lymphedema-specific exercise barriers self-efficacy subscale was developed and validated using a cohort of 106 cancer survivors with cancer-related lymphedema, from Brisbane, Australia. An initial ten-item lymphedema-specific barrier subscale was developed and tested, with participant feedback and principal components analysis results used to guide development of the final version. Validity and test-retest reliability analyses were conducted on the final subscale. The final lymphedema-specific subscale contained five items. Principal components analysis revealed these items loaded highly (>0.75) on a separate factor when tested with a well-established nine-item general barriers scale. The final five-item subscale demonstrated good construct and criterion validity, high internal consistency (Cronbach's alpha = 0.93) and test-retest reliability (ICC = 0.67, p exercise barriers self-efficacy in individuals with cancer-related lymphedema. This scale can be used in conjunction with an existing general exercise barriers scale to enhance exercise adherence in this understudied patient group.

  1. Implementation of renewable energy technologies - Opportunities and barriers. Egypt country study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The project used case studies of renewable energy implementation projects to analyse the reasons for success or failure of specific projects or technologies. In particular the study aimed to identify possibilities for 'removing' the main barriers and thus 'promoting' increased implementation of (RETs), and to 'generalise' the experiences from the case studies and produce results that can be disseminated and utilized further in a planned second phase. The specific objectives for Egypt Country Study were: 1) To determine, on the basis of analysis of the past experience, the barriers against implementation of RETs in Egypt, and to identify the favourable conditions and actions required for such implementation. 2) To apply the knowledge gained and results of the analysis of past projects for a detailed analysis of barriers to a chosen set of potential RETs implementation projects with view to success. 3) To identify specific RET projects for implementation including necessary actions to overcome identified barriers. The case study revealed that; for Domestic Solar Water Heating (DSWH) the main barriers are; the economic barriers followed by the awareness / information barriers, then the Technical and Institution barriers. For the PV rural electrification, the most important barriers are; the economic and financial barriers, the awareness and information barriers then the technical barriers. For the large-scale biogas systems, the main barriers are the institution and capacity, economic, policy and awareness / information respectively. According to the project results the main actions that could be taken to overcome the barriers and make use of the available opportunities are: Economic / Financial: 1) Creation of new financial schemes for the RETs applications components and systems. 2) Reducing the taxes and duties for the components and / or materials needed for Renewable Energy (RE) systems. 3) More government-supported market incentives

  2. Implementation of renewable energy technologies - Opportunities and barriers. Egypt country study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The project used case studies of renewable energy implementation projects to analyse the reasons for success or failure of specific projects or technologies. In particular the study aimed to identify possibilities for 'removing' the main barriers and thus 'promoting' increased implementation of (RETs), and to 'generalise' the experiences from the case studies and produce results that can be disseminated and utilized further in a planned second phase. The specific objectives for Egypt Country Study were: 1) To determine, on the basis of analysis of the past experience, the barriers against implementation of RETs in Egypt, and to identify the favourable conditions and actions required for such implementation. 2) To apply the knowledge gained and results of the analysis of past projects for a detailed analysis of barriers to a chosen set of potential RETs implementation projects with view to success. 3) To identify specific RET projects for implementation including necessary actions to overcome identified barriers. The case study revealed that; for Domestic Solar Water Heating (DSWH) the main barriers are; the economic barriers followed by the awareness / information barriers, then the Technical and Institution barriers. For the PV rural electrification, the most important barriers are; the economic and financial barriers, the awareness and information barriers then the technical barriers. For the large-scale biogas systems, the main barriers are the institution and capacity, economic, policy and awareness / information respectively. According to the project results the main actions that could be taken to overcome the barriers and make use of the available opportunities are: Economic / Financial: 1) Creation of new financial schemes for the RETs applications components and systems. 2) Reducing the taxes and duties for the components and / or materials needed for Renewable Energy (RE) systems. 3) More government-supported market incentives to encourage further

  3. Factors related to environmental barriers experienced by persons with and without disabilities in diverse African settings.

    Directory of Open Access Journals (Sweden)

    Surona Visagie

    Full Text Available This paper explores differences in experienced environmental barriers between individuals with and without disabilities and the impact of additional factors on experienced environmental barriers. Data was collected in 2011-2012 by means of a two-stage cluster sampling and comprised 400-500 households in different sites in South Africa, Sudan Malawi and Namibia. Data were collected through self-report survey questionnaires. In addition to descriptive statistics and simple statistical tests a structural equation model was developed and tested. The combined file comprised 9,307 participants. The Craig Hospital Inventory of Environmental Factors was used to assess the level of environmental barriers. Transportation, the natural environment and access to health care services created the biggest barriers. An exploratory factor analysis yielded support for a one component solution for environmental barriers. A scale was constructed by adding the items together and dividing by number of items, yielding a range from one to five with five representing the highest level of environmental barriers and one the lowest. An overall mean value of 1.51 was found. Persons with disabilities scored 1.66 and persons without disabilities 1.36 (F = 466.89, p < .001. Bivariate regression analyses revealed environmental barriers to be higher among rural respondents, increasing with age and severity of disability, and lower for those with a higher level of education and with better physical and mental health. Gender had an impact only among persons without disabilities, where women report more barriers than men. Structural equation model analysis showed that socioeconomic status was significantly and negatively associated with environmental barriers. Activity limitation is significantly associated with environmental barriers when controlling for a number of other individual characteristics. Reducing barriers for the general population would go some way to reduce the impact

  4. Modelling of epitaxial film growth with an Ehrlich-Schwoebel barrier dependent on the step height

    International Nuclear Information System (INIS)

    Leal, F F; Ferreira, S C; Ferreira, S O

    2011-01-01

    The formation of mounded surfaces in epitaxial growth is attributed to the presence of barriers against interlayer diffusion in the terrace edges, known as Ehrlich-Schwoebel (ES) barriers. We investigate a model for epitaxial growth using an ES barrier explicitly dependent on the step height. Our model has an intrinsic topological step barrier even in the absence of an explicit ES barrier. We show that mounded morphologies can be obtained even for a small barrier while a self-affine growth, consistent with the Villain-Lai-Das Sarma equation, is observed in the absence of an explicit step barrier. The mounded surfaces are described by a super-roughness dynamical scaling characterized by locally smooth (facetted) surfaces and a global roughness exponent α > 1. The thin film limit is featured by surfaces with self-assembled three-dimensional structures having an aspect ratio (height/width) that may increase or decrease with temperature depending on the strength of the step barrier. (fast track communication)

  5. Barriers to Use of Family Planning Methods Among Heterosexual Mexican Couples.

    Science.gov (United States)

    Arias, María Luisa Flores; Champion, Jane Dimmitt; Soto, Norma Elva Sáenz; Tovar, Marlene; Dávila, Sandra Paloma Esparza

    2017-05-01

    Family planning has become increasingly important as a fundamental component of sexual health and as such is offered via public health systems worldwide. Identification of barriers to use of family planning methods among heterosexual couples living in Mexico is indicated to facilitate access to family planning methods. Barriers to family planning methods were assessed among Mexican heterosexual, sexually active males and females of reproductive age, using a modified Spanish version of the Barriers to the Use of Family Planning Methods scale (Cronbach's alpha = .89, subscales ranging from .53 to .87). Participants were recruited via convenience sampling in ambulatory care clinics within a metropolitan area in Central Mexico. Participants included 52 heterosexual couples aged 18-35 years (N = 104). Sociodemographic comparisons by gender identified older age and higher education, income, and numbers of sexual partners among men than women. More men (50%) than women (25%) were currently using family planning methods; however, 80% overall indicated intentions for its use. Overall, male condoms were used and intended for use most often by men than women. Significant gender-specific differences were found, with men (71.15%) reporting no family planning barriers, whereas women (55.66%) reported barriers including low socioeconomic status, medical concerns, and stigma. The modified Spanish translation demonstrated usefulness for measuring barriers to family planning methods use in Mexico among heterosexual males and females of reproductive age. Barriers identified by Mexican women in this study may be addressed to reduce potential barriers to family planning among Mexican populations.

  6. Does weight status influence perceptions of physical activity barriers among African-American women?

    Science.gov (United States)

    Genkinger, Jeanine M; Jehn, Megan L; Sapun, Marcella; Mabry, Iris; Young, Deborah Rohm

    2006-01-01

    Many African-American women fail to participate in regular physical activity. Weight status may influence physical activity barriers. This study examined the frequency and type of barriers. Participants in this study were enrolled in Project EXE-L (Exercising Ladies Excel), a six-month, church-based, randomized trial of moderate-intensity physical activity based in Baltimore city and county in Maryland. Participants were composed of African-American women who attended one of the participating churches, had friends who were church members, or who lived in neighborhoods surrounding one of the churches. Individuals who were between the ages of 25 and 70 years, were not regularly physically active (defined as not engaging in moderate-intensity activity more than three times per week), and were able to participate in moderate-intensity activity met eligibility criteria to participate in the trial. Barriers to physical activity were evaluated with the Steinhardt/Dishman Barriers for Habitual Physical Activity Scale at baseline. One hundred twenty women were classified as normal weight (body mass index [BMI]: or = 30 kg/m2). Obese participants were more likely to report "lack of motivation" as a barrier compared with normal-weight participants (63% vs 31%). Normal-weight and overweight participants were more likely to report no barriers compared with the obese (31%, 0%, 5%, respectively, P<.05). Barriers for African-American women may vary by BMI status. By defining these unique barriers, effective physical activity interventions can be developed.

  7. Schizophrenia: breaking down the barriers.

    Science.gov (United States)

    Haghighat, R

    1997-01-01

    This paper reviews the key issues presented during the Fourth International Conference on Schizophrenia, which was held in October 1996 in Vancouver, Canada. The main emphasis was placed on the problem of stigma, loneliness and work as well as on the necessity to further elucidate the physiopathology of schizophrenia. Some of the barriers discussed are unlikely to disappear from human societies in the short term with any possible cure for schizophrenia as they are part of any major long-term illness, of which there is a long and ever increasing list.

  8. Fission barriers of superheavy nuclei

    International Nuclear Information System (INIS)

    Burvenich, T.

    2001-01-01

    Full text: Self consistent microscopic mean-field models are powerful tools for the description of nuclear structure phenomena in the region of known elements, where they have reached a good quality. Especially the Skyrme-Hartree-Fock (SHF) method and the Relativistic Mean-Field (RMF) model will be considered in the discussion of the properties of these models. When it comes to extrapolation to the region of superheavy elements, though there is agreement concerning the global trends, these model exhibit significant differences in their predictions concerning fission barrier heights and structures. (Author)

  9. Socio-technical inertia: Understanding the barriers to electric vehicles

    International Nuclear Information System (INIS)

    Steinhilber, Simone; Wells, Peter; Thankappan, Samarthia

    2013-01-01

    It is widely accepted that electrification of the transport sector is one of several technological trajectories that could redress some of the environmental issues associated with the growth in travel demand including climate change and oil demand at a global scale, and air quality and noise pollution at the urban scale. Electric vehicles have been considered a promising technology at repeated intervals over the last century, but this promise has not been realised. This paper is a contribution to understanding the key tools and strategies that might enable the successful introduction of new technologies and innovations by exploring the key barriers to electric vehicles encountered in two countries (UK and Germany) where the automobile industry has been historically significant. The study evaluates stakeholders' opinions on relevant regulation, infrastructure investment, R and D incentives, and consumer incentives. The key findings of the research are that the introduction and penetration of EVs is confronted by several barriers that inhibit a larger market penetration under current conditions, which in turn casts doubt on the assumptions of strategic niche management and transitions theory. - Highlights: • Immature developing technology reason behind non-commercialisation of EVs. • EVs currently do not present a significant benefit to the electricity sector. • EVs rely on a mix of regulatory and government measures for their development. • EVs face lock-in problem of unsustainable technologies and related barriers. • Positive milieu for innovation in vehicle technology and business models are required

  10. Framing scales and scaling frames

    NARCIS (Netherlands)

    van Lieshout, M.; Dewulf, A.; Aarts, N.; Termeer, K.

    2009-01-01

    Policy problems are not just out there. Actors highlight different aspects of a situation as problematic and situate the problem on different scales. In this study we will analyse the way actors apply scales in their talk (or texts) to frame the complex decision-making process of the establishment

  11. Double barrier system for an in situ conversion process

    Science.gov (United States)

    McKinzie, Billy John [Houston, TX; Vinegar, Harold J [Bellaire, TX; Cowan, Kenneth Michael [Sugar land, TX; Deeg, Wolfgang Friedrich Johann [Houston, TX; Wong, Sau-Wai [Rijswijk, NL

    2009-05-05

    A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed around at least a portion of the first barrier. A separation space exists between the first barrier and the second barrier.

  12. Mediated Intercultural Communication Barrier in No Drama Zone! Group

    OpenAIRE

    Lizal, Valentino

    2015-01-01

    This research study aimed to describe the mediated intercultural communication barriers in the No Drama Zone! group. This study is a qualitative descriptive type of research, with case study method. By doing in depth interview and observation, researcher found two barriers that generates other barriers in the group's mediated intercultural communication. The two big barriers were: language and physical barriers. Language barriers in this group generated two barriers, emotional barrier and pe...

  13. Barriers to hydroxyurea adherence and health-related quality of life in adolescents and young adults with sickle cell disease.

    Science.gov (United States)

    Badawy, Sherif M; Thompson, Alexis A; Penedo, Frank J; Lai, Jin-Shei; Rychlik, Karen; Liem, Robert I

    2017-06-01

    To identify barriers to hydroxyurea adherence (negative beliefs, access, and/or recall barriers), and their relationship to adherence rates and health-related quality of life (HRQOL) among adolescents and young adults (AYA) with sickle cell disease (SCD). A cross-sectional survey was administered to 34 AYAs (12-22 years old) in SCD clinics from January to December 2015. Study measures included Brief Medication Questionnaire, Modified Morisky Adherence Scale 8-items, visual analog scale, and Patient Reported Outcomes Measurement Information System. Participants (59% male; 91% Black) had a median age of 13.5 years (IQR 12-18). Participants reported negative beliefs (32%), recall barriers (44%), and access barriers (32%). Participants with recall barriers reported worse pain (P=.02), fatigue (P=.05), and depression (P=.05). The number of adherence barriers inversely correlated with adherence level using ©MMAS-8 (r s =-.38, P=.02) and VAS dose (r s =-.25, P=.14) as well as MCV (r s =-.45, P=.01) and HbF% (r s =-.36, P=.05), suggesting higher hydroxyurea adherence in patients with fewer barriers. Patients with fewer barriers to hydroxyurea adherence were more likely to have higher adherence rates and better HRQOL scores. Routine assessment of hydroxyurea adherence and its related barriers could provide actionable information to improve adherence rates, HRQOL, and other clinical outcomes. © 2017 The Authors. European Journal of Haematology Published by John Wiley & Sons Ltd.

  14. Subsurface barrier verification technologies, informal report

    International Nuclear Information System (INIS)

    Heiser, J.H.

    1994-06-01

    One of the more promising remediation options available to the DOE waste management community is subsurface barriers. Some of the uses of subsurface barriers include surrounding and/or containing buried waste, as secondary confinement of underground storage tanks, to direct or contain subsurface contaminant plumes and to restrict remediation methods, such as vacuum extraction, to a limited area. To be most effective the barriers should be continuous and depending on use, have few or no breaches. A breach may be formed through numerous pathways including: discontinuous grout application, from joints between panels and from cracking due to grout curing or wet-dry cycling. The ability to verify barrier integrity is valuable to the DOE, EPA, and commercial sector and will be required to gain full public acceptance of subsurface barriers as either primary or secondary confinement at waste sites. It is recognized that no suitable method exists for the verification of an emplaced barrier's integrity. The large size and deep placement of subsurface barriers makes detection of leaks challenging. This becomes magnified if the permissible leakage from the site is low. Detection of small cracks (fractions of an inch) at depths of 100 feet or more has not been possible using existing surface geophysical techniques. Compounding the problem of locating flaws in a barrier is the fact that no placement technology can guarantee the completeness or integrity of the emplaced barrier. This report summarizes several commonly used or promising technologies that have been or may be applied to in-situ barrier continuity verification

  15. Operation and scalability of dopant-segregated Schottky barrier MOSFETs with recessed channels

    International Nuclear Information System (INIS)

    Shih, Chun-Hsing; Hsia, Jui-Kai

    2013-01-01

    Recessed channels were used in scaled dopant-segregated Schottky barrier MOSFETs (DS-SBMOS) to control the severe short-channel effect. The physical operation and device scalability of the DS-SBMOS resulting from the presence of recessed channels and associated gate-corners are elucidated. The coupling of Schottky and gate-corner barriers has a key function in determining the on–off switching and drain current. The gate-corner barriers divide the channel into three regions for protection from the drain penetration field. To prevent resistive degradations in the drive current, an alternative asymmetric recessed channel (ARC) without a source-side gate-corner is proposed to simultaneously optimize both the short-channel effect and drive current in the scaled DS-SBMOS. By employing the proposed ARC architecture, the DS-SBMOS devices can be successfully scaled down, making them promising candidates for next-generation CMOS devices. (paper)

  16. Overcoming Barriers in Unhealthy Settings

    Directory of Open Access Journals (Sweden)

    Michael K. Lemke

    2016-03-01

    Full Text Available We investigated the phenomenon of sustained health-supportive behaviors among long-haul commercial truck drivers, who belong to an occupational segment with extreme health disparities. With a focus on setting-level factors, this study sought to discover ways in which individuals exhibit resiliency while immersed in endemically obesogenic environments, as well as understand setting-level barriers to engaging in health-supportive behaviors. Using a transcendental phenomenological research design, 12 long-haul truck drivers who met screening criteria were selected using purposeful maximum sampling. Seven broad themes were identified: access to health resources, barriers to health behaviors, recommended alternative settings, constituents of health behavior, motivation for health behaviors, attitude toward health behaviors, and trucking culture. We suggest applying ecological theories of health behavior and settings approaches to improve driver health. We also propose the Integrative and Dynamic Healthy Commercial Driving (IDHCD paradigm, grounded in complexity science, as a new theoretical framework for improving driver health outcomes.

  17. Barriers to medical error reporting

    Directory of Open Access Journals (Sweden)

    Jalal Poorolajal

    2015-01-01

    Full Text Available Background: This study was conducted to explore the prevalence of medical error underreporting and associated barriers. Methods: This cross-sectional study was performed from September to December 2012. Five hospitals, affiliated with Hamadan University of Medical Sciences, in Hamedan,Iran were investigated. A self-administered questionnaire was used for data collection. Participants consisted of physicians, nurses, midwives, residents, interns, and staffs of radiology and laboratory departments. Results: Overall, 50.26% of subjects had committed but not reported medical errors. The main reasons mentioned for underreporting were lack of effective medical error reporting system (60.0%, lack of proper reporting form (51.8%, lack of peer supporting a person who has committed an error (56.0%, and lack of personal attention to the importance of medical errors (62.9%. The rate of committing medical errors was higher in men (71.4%, age of 50-40 years (67.6%, less-experienced personnel (58.7%, educational level of MSc (87.5%, and staff of radiology department (88.9%. Conclusions: This study outlined the main barriers to reporting medical errors and associated factors that may be helpful for healthcare organizations in improving medical error reporting as an essential component for patient safety enhancement.

  18. Experimental Approach of Fault Movement on an Engineered Barrier System

    International Nuclear Information System (INIS)

    Lee, Minsoo; Choi, Heuijoo; Kim, Heuna

    2012-01-01

    Safety evaluation of an engineered barrier system against fault movement at underground disposal region for high level waste (HLW) is tried using a miniature bore-shear apparatus. For the purpose, a miniature bore-shear apparatus simulating an EBS (engineered barrier system) was manufactured in 1/30 scale. And using the developed apparatus, bore-shear tests were performed twice. During the tests, pressure variations were checked at 6 points around buffer zone, and then a rotational angle of the test vessel was checked. The achieved pressure data were compared with those from analytical modeling, which is based on Drucker-Prager model. At initial shearing step, high pressure was recorded at some point but it decreased rapidly. For the better understanding of fault movement, the modification of an analytical model and the accumulation of experimental experience were required

  19. Experimental Approach of Fault Movement on an Engineered Barrier System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minsoo; Choi, Heuijoo; Kim, Heuna [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Safety evaluation of an engineered barrier system against fault movement at underground disposal region for high level waste (HLW) is tried using a miniature bore-shear apparatus. For the purpose, a miniature bore-shear apparatus simulating an EBS (engineered barrier system) was manufactured in 1/30 scale. And using the developed apparatus, bore-shear tests were performed twice. During the tests, pressure variations were checked at 6 points around buffer zone, and then a rotational angle of the test vessel was checked. The achieved pressure data were compared with those from analytical modeling, which is based on Drucker-Prager model. At initial shearing step, high pressure was recorded at some point but it decreased rapidly. For the better understanding of fault movement, the modification of an analytical model and the accumulation of experimental experience were required.

  20. An exploration study to detect important barriers for knowledge management

    Directory of Open Access Journals (Sweden)

    Jalil Ghafourian

    2014-01-01

    Full Text Available This paper presents an empirical investigation to find the important factors influencing implementation of knowledge management in revenue agencies in Iran. The proposed study designs a questionnaire and distributes it among some experts and, using principal component analysis, the study detects important barriers for knowledge management implications. The study selects 170 people from 880 regular employees who work for revenue agency and distributes the questionnaire designed in Likert scale. Cronbach alpha has been determined as 0.70, which is well above the minimum acceptable level. In terms of knowledge management, the study determines six factors including support for creativity and innovation, knowledge sharing, trust, employee promotion plan, mission and training programs and they represent 66.57% of the described factors. In addition, in terms of barriers, job security, cultural issues, individual differences, infrastructure, organizational structure and lack of vision are the most important issues representing 61.98% of the factors.

  1. Mining twitter to understand the smoking cessation barriers.

    Science.gov (United States)

    Krittanawong, Chayakrit; Wang, Zhen

    2017-10-26

    Smoking cessation is challenging and lack of positive support is a known major barrier to quitting cigarettes. Previous studies have suggested that social influences might increase smokers' awareness of social norms for appropriate behavior, which might lead to smoking cessation. Although social media use is increasing among young adults in the United States, research on the relationship between social media use and smoking cessation is lacking. Twitter has provided a rich source of information for researchers, but no overview exists as to how the field uses Twitter in smoking cessation research. To the best of our knowledge, this study conducted a data mining analysis of Twitter to assess barriers to smoking cessation. In conclusion, Twitter is a cost-effective tool with the potential to disseminate information on the benefits of smoking cessation and updated research to the Twitter community on a global scale.

  2. An automated approach for extracting Barrier Island morphology from digital elevation models

    Science.gov (United States)

    Wernette, Phillipe; Houser, Chris; Bishop, Michael P.

    2016-06-01

    The response and recovery of a barrier island to extreme storms depends on the elevation of the dune base and crest, both of which can vary considerably alongshore and through time. Quantifying the response to and recovery from storms requires that we can first identify and differentiate the dune(s) from the beach and back-barrier, which in turn depends on accurate identification and delineation of the dune toe, crest and heel. The purpose of this paper is to introduce a multi-scale automated approach for extracting beach, dune (dune toe, dune crest and dune heel), and barrier island morphology. The automated approach introduced here extracts the shoreline and back-barrier shoreline based on elevation thresholds, and extracts the dune toe, dune crest and dune heel based on the average relative relief (RR) across multiple spatial scales of analysis. The multi-scale automated RR approach to extracting dune toe, dune crest, and dune heel based upon relative relief is more objective than traditional approaches because every pixel is analyzed across multiple computational scales and the identification of features is based on the calculated RR values. The RR approach out-performed contemporary approaches and represents a fast objective means to define important beach and dune features for predicting barrier island response to storms. The RR method also does not require that the dune toe, crest, or heel are spatially continuous, which is important because dune morphology is likely naturally variable alongshore.

  3. Hanford protoype surface barrier status report: FY 1994

    International Nuclear Information System (INIS)

    Gee, G.W.; Freeman, H.D.; Walters, W.H. Jr.; Ligotke, M.W.; Campbell, M.D.; Ward, A.L.; Link, S.O.; Smith, S.K.; Gilmore, B.G.; Romine, R.A.

    1994-12-01

    A full-scale prototype surface barrier has been constructed at the 200 BP-1 Operable Unit in the 200 East Area of the Hanford Site. The prototype barrier has been built to evaluate design, construction, and performance features of a surface barrier that may be used for in-place disposal of wastes at the Hanford Site. The design basis and construction of the prototype have been documented. A testing and monitoring plan has been published outlining specific tests planned for the prototype. The current report describes initial testing activities conducted in FY 1994 and outlines activities for testing and monitoring at the prototype barrier in the future. Asphalt permeability was tested during construction of the prototype in April and May 1994. Cores taken from the asphalt concrete layer were tested in the laboratory and found to have hydraulic conductivities below 1E-09 cm/s. Field measurements of hydraulic conductivity taken on the asphalt concrete using a specially-designed falling head permeameter were more than ten times higher than those from core tests. The higher values are attributed to transient flow through the permeameter seal. In spite of this difficulty, the more rapid field measurements (1-day tests in the field compared to 3 months in the laboratory) gave values as low as IE-09 cm/s and averaged about IE-08 cm/s. Samples of fluid-applied asphalt material, used as a sealant on the asphalt concrete layer, were. tested in the laboratory and found to have hydraulic conductivities below IE-10 cm/s. Measurements of hydraulic conductivity taken on an adjacent asphalt test pad using a sealed double-ring infiltrometer (SDRI) were initiated in September 1994 and are expected to be completed in November 1994. Construction of the prototype surface barrier was completed in August 1994

  4. Richards Barrier LA Reference Design Feature Evaluation

    International Nuclear Information System (INIS)

    N.E. Kramer

    1999-01-01

    The Richards Barrier is one of the design features of the repository to be considered for the License Application (LA), Richards was a soil scientist who first described the diversion of moisture between two materials with different hydrologic properties. In this report, a Richards Barrier is a special type of backfill with a fine-grained material (such as sand) overlaying a coarse-grained material (such as gravel). Water that enters an emplacement drift will first encounter the fine-grained material and be transported around the coarse-grained material covering the waste package, thus protecting the waste package from contact with most of the groundwater. The objective of this report is to discuss the benefits and liabilities to the repository by the inclusion of a Richards Barrier type backfill in emplacement drifts. The Richards Barrier can act as a barrier to water flow, can reduce the waste package material dissolution rate, limit mobilization of the radionuclides, and can provide structural protection for the waste package. The scope of this report is to: (1) Analyze the behavior of barrier materials following the intrusion of groundwater for influxes of 1 to 300 mm per year. The report will demonstrate diversion of groundwater intrusions into the barrier over an extended time period when seismic activity and consolidation may cause the potential for liquefaction and settlement of the Richards Barrier. (2) Review the thermal effects of the Richards Barrier on material behavior. (3) Analyze the effect of rockfall on the performance of the Richards Barrier and the depth of the barrier required to protect waste packages under the barrier. (4) Review radiological and heating conditions on placement of multiple layers of the barrier. Subsurface Nuclear Safety personnel will perform calculations to determine the radiation reduction-time relationship and shielding capacity of the barrier. (5) Evaluate the effects of ventilation on cooling of emplacement drifts and

  5. Clays in natural and engineered barriers for radioactive waste confinement

    International Nuclear Information System (INIS)

    2007-01-01

    The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO 2 geological sequestration, chemical waste isolation

  6. Clays in natural and engineered barriers for radioactive waste confinement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO{sub 2} geological sequestration, chemical waste isolation

  7. Entropic Barriers for Two-Dimensional Quantum Memories

    Science.gov (United States)

    Brown, Benjamin J.; Al-Shimary, Abbas; Pachos, Jiannis K.

    2014-03-01

    Comprehensive no-go theorems show that information encoded over local two-dimensional topologically ordered systems cannot support macroscopic energy barriers, and hence will not maintain stable quantum information at finite temperatures for macroscopic time scales. However, it is still well motivated to study low-dimensional quantum memories due to their experimental amenability. Here we introduce a grid of defect lines to Kitaev's quantum double model where different anyonic excitations carry different masses. This setting produces a complex energy landscape which entropically suppresses the diffusion of excitations that cause logical errors. We show numerically that entropically suppressed errors give rise to superexponential inverse temperature scaling and polynomial system size scaling for small system sizes over a low-temperature regime. Curiously, these entropic effects are not present below a certain low temperature. We show that we can vary the system to modify this bound and potentially extend the described effects to zero temperature.

  8. Scaffold translation: barriers between concept and clinic.

    Science.gov (United States)

    Hollister, Scott J; Murphy, William L

    2011-12-01

    Translation of scaffold-based bone tissue engineering (BTE) therapies to clinical use remains, bluntly, a failure. This dearth of translated tissue engineering therapies (including scaffolds) remains despite 25 years of research, research funding totaling hundreds of millions of dollars, over 12,000 papers on BTE and over 2000 papers on BTE scaffolds alone in the past 10 years (PubMed search). Enabling scaffold translation requires first an understanding of the challenges, and second, addressing the complete range of these challenges. There are the obvious technical challenges of designing, manufacturing, and functionalizing scaffolds to fill the Form, Fixation, Function, and Formation needs of bone defect repair. However, these technical solutions should be targeted to specific clinical indications (e.g., mandibular defects, spine fusion, long bone defects, etc.). Further, technical solutions should also address business challenges, including the need to obtain regulatory approval, meet specific market needs, and obtain private investment to develop products, again for specific clinical indications. Finally, these business and technical challenges present a much different model than the typical research paradigm, presenting the field with philosophical challenges in terms of publishing and funding priorities that should be addressed as well. In this article, we review in detail the technical, business, and philosophical barriers of translating scaffolds from Concept to Clinic. We argue that envisioning and engineering scaffolds as modular systems with a sliding scale of complexity offers the best path to addressing these translational challenges. © Mary Ann Liebert, Inc.

  9. Measuring solvent barrier properties of paper

    International Nuclear Information System (INIS)

    Bollström, Roger; Saarinen, Jarkko J; Toivakka, Martti; Räty, Jukka

    2012-01-01

    New methods for measuring barrier properties against solvents, acids and bases on dispersion coated paper were developed and investigated. Usability, reliability and repeatability were compared both between the new methods and with the standardized method for measuring barrier properties against water vapor. Barrier properties could be measured with all methods and the results obtained by the different methods were in correlation with each other. A qualitative method based on a trace color provided an indicative result, whereas further developed methods also took into account the durability. The effective barrier lifetime could be measured by measuring the conductivity through the substrate as a function of time, or by utilizing a glass prism where the change in refractive index caused by penetrated liquid was monitored, also as a function of time. Barrier properties against water and humidity were also measured and were found not to be predictors for barrier properties against either solvents, or acids or bases, which supports the need to develop new methods

  10. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  11. Breaking the Barriers to the Circular Economy

    OpenAIRE

    Kirchherr, J.W.; Hekkert, M.P.; Bour, Ruben; Huijbrechtse-Truijens, Anne; Kostense-Smit, Erica; Muller, Jennifer

    2017-01-01

    The Copernicus Institute of Sustainable Development, Utrecht University, the Netherlands and Deloitte have jointly carried out research on barriers to the Circular Economy (CE) in the European Union. For this research, a survey with 153 businesses, 55 government officials and expert interviews with forty-seven thought leaders on the circular economy from businesses, governments, academia and NGOs have been carried out. Two types of barriers emerged as main barriers Firstly, there are the cult...

  12. Emergent Behavior of Coupled Barrier Island - Resort Systems

    Science.gov (United States)

    McNamara, D. E.; Werner, B. T.

    2004-12-01

    Barrier islands are attractive sites for resorts. Natural barrier islands experience beach erosion and island overwash during storms, beach accretion and dune building during inter-storm periods, and migration up the continental shelf as sea level rises. Beach replenishment, artificial dune building, seawalls, jetties and groins have been somewhat effective in protecting resorts against erosion and overwash during storms, but it is unknown how the coupled system will respond to long-term sea level rise. We investigate coupled barrier island - resort systems using an agent-based model with three components: natural barrier islands divided into a series of alongshore cells; resorts controlled by markets for tourism and hotel purchases; and coupling via storm damage to resorts and resort protection by government agents. Modeled barrier islands change by beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms. In the resort hotel market, developer agents build hotels and hotel owning agents purchase them using predictions of future revenue and property appreciation, with the goal of maximizing discounted utility. In the tourism market, hotel owning agents set room rental prices to maximize profit and tourist agents choose vacation destinations maximizing a utility based on beach width, price and word-of-mouth. Government agents build seawalls, groins and jetties, and widen the beach and build up dunes by adding sand to protect resorts from storms, enhance beach quality, and maximize resort revenue. Results indicate that barrier islands and resorts evolve in a coupled manner to resort size saturation, with resorts protected against small-to-intermediate-scale storms under fairly stable sea level. Under extended, rapidly rising sea level, protection measures enhance the effect of large storms, leading to emergent behavior in the form of limit cycles or barrier submergence

  13. Scaling down

    Directory of Open Access Journals (Sweden)

    Ronald L Breiger

    2015-11-01

    Full Text Available While “scaling up” is a lively topic in network science and Big Data analysis today, my purpose in this essay is to articulate an alternative problem, that of “scaling down,” which I believe will also require increased attention in coming years. “Scaling down” is the problem of how macro-level features of Big Data affect, shape, and evoke lower-level features and processes. I identify four aspects of this problem: the extent to which findings from studies of Facebook and other Big-Data platforms apply to human behavior at the scale of church suppers and department politics where we spend much of our lives; the extent to which the mathematics of scaling might be consistent with behavioral principles, moving beyond a “universal” theory of networks to the study of variation within and between networks; and how a large social field, including its history and culture, shapes the typical representations, interactions, and strategies at local levels in a text or social network.

  14. Barriers for realisation of energy savings in buildings; Barrierer for realisering af energibesparelser i bygninger

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, O.M.

    2004-07-01

    Many years' efforts within the energy labelling area have shown large saving potentials in heating and use of electricity in buildings. At the same time it has been proved that these saving potentials, even when economically advantageous, only are cashed to a limited extent. The reason to this is ascribed to barriers that meet the individual building owner who wants to start saving energy. Most barriers are known and a lot of these have been sought overcome for some time. The questions are how many barriers still exist, have new barriers arisen and the character of these barriers. On this background the objective of this survey has been to concretize and study the barriers, which are blocking reasonable energy savings. Focus has especially been on barriers for realisation of heating savings, but through a general evaluation of energy savings of barriers other forms of energy saving methods have been taken into consideration. Special interest has been directed towards houses, typically one family houses, which are affected by the Energy Labelling Scheme. The concept barriers include all kinds of barriers, also barriers that not are acknowledged as barriers by the individual house owner, or that on closer inspection turn out to be something else than actual barriers. This note suggests an alternative inertia model, in order to create an idea of the inertness characteristic of the many house owners who understand the message but fail to act on it. (BA)

  15. Time scales of tunneling decay of a localized state

    International Nuclear Information System (INIS)

    Ban, Yue; Muga, J. G.; Sherman, E. Ya.; Buettiker, M.

    2010-01-01

    Motivated by recent time-domain experiments on ultrafast atom ionization, we analyze the transients and time scales that characterize, aside from the relatively long lifetime, the decay of a localized state by tunneling. While the tunneling starts immediately, some time is required for the outgoing flux to develop. This short-term behavior depends strongly on the initial state. For the initial state, tightly localized so that the initial transients are dominated by over-the-barrier motion, the time scale for flux propagation through the barrier is close to the Buettiker-Landauer traversal time. Then a quasistationary, slow-decay process follows, which sets ideal conditions for observing diffraction in time at longer times and distances. To define operationally a tunneling time at the barrier edge, we extrapolate backward the propagation of the wave packet that escaped from the potential. This extrapolated time is considerably longer than the time scale of the flux and density buildup at the barrier edge.

  16. High Performance Multi Barrier Thermionic Devices

    National Research Council Canada - National Science Library

    Vashaee, Daryoosh; Shakouri, Ali

    2003-01-01

    Thermoelectric transport perpendicular to layers in multiple barrier superlattice structures is investigated theoretically in two limiting cases of no lateral momentum scattering and strong scattering...

  17. Water and contaminant movement: migration barriers

    International Nuclear Information System (INIS)

    Lane, L.J.; Nyhan, J.W.

    1984-11-01

    Migration barriers are used in shallow land burial facilities to slow or stop the movement of water and contaminants and are discussed here as a single component embedded in a complex environmental system. Analytical solutions to solute transport equations are used to approximate the behavior of migration barriers and to derive design criteria for control of subsurface water and contaminant migration. Various types of migration barriers are compared and design recommendations are made for shallow land burial trench caps and liners. Needed improvements and suggested field experiments for future designs of migration barriers are then discussed relative to the management of low-level radioactive wastes

  18. Barriers Approach to Innovation in Academic Libraries

    Directory of Open Access Journals (Sweden)

    Fu-Hsuan Chuang

    2016-11-01

    Full Text Available Innovation in academic libraries is not a brand new issue. Academic libraries can benefit from successful innovation, since innovation is a key contributor to gaining and sustaining competitive advantage for survival. Building on two case studies, 28 participants from leadership teams to practitioners are involved, the qualitative findings identified the specific two types of barriers that academic libraries face by applying a barriers approach to innovation, that’s, environmental and organizational barriers. Especially, seven dimensions of two types of barriers to innovation are found.

  19. Barriers to healthcare for transgender individuals.

    Science.gov (United States)

    Safer, Joshua D; Coleman, Eli; Feldman, Jamie; Garofalo, Robert; Hembree, Wylie; Radix, Asa; Sevelius, Jae

    2016-04-01

    Transgender persons suffer significant health disparities and may require medical intervention as part of their care. The purpose of this manuscript is to briefly review the literature characterizing barriers to healthcare for transgender individuals and to propose research priorities to understand mechanisms of those barriers and interventions to overcome them. Current research emphasizes sexual minorities' self-report of barriers, rather than using direct methods. The biggest barrier to healthcare reported by transgender individuals is lack of access because of lack of providers who are sufficiently knowledgeable on the topic. Other barriers include: financial barriers, discrimination, lack of cultural competence by providers, health systems barriers, and socioeconomic barriers. National research priorities should include rigorous determination of the capacity of the US healthcare system to provide adequate care for transgender individuals. Studies should determine knowledge and biases of the medical workforce across the spectrum of medical training with regard to transgender medical care; adequacy of sufficient providers for the care required, larger social structural barriers, and status of a framework to pay for appropriate care. As well, studies should propose and validate potential solutions to address identified gaps.

  20. Antimicrobial Peptides, Infections and the Skin Barrier

    DEFF Research Database (Denmark)

    Clausen, Maja Lisa; Agner, Tove

    2016-01-01

    The skin serves as a strong barrier protecting us from invading pathogens and harmful organisms. An important part of this barrier comes from antimicrobial peptides (AMPs), which are small peptides expressed abundantly in the skin. AMPs are produced in the deeper layers of the epidermis and trans......The skin serves as a strong barrier protecting us from invading pathogens and harmful organisms. An important part of this barrier comes from antimicrobial peptides (AMPs), which are small peptides expressed abundantly in the skin. AMPs are produced in the deeper layers of the epidermis...

  1. Radon barrier: Method of testing airtightness

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Buch-Hansen, Thomas Cornelius

    2017-01-01

    The test method NBI 167/02 Radon membrane: Test of airtightness can be used for determining the airtightness of a radon barrier as a system solution. The test determines the air infiltration through the radon barrier for a number of levels of air pressure differences. The airflow through versus...... of the barrier with the low air pressure, through a well-defined opening, as a modification of the test method in general. Results, obtained using the improved test method, are shown for a number of radon barriers tested....

  2. Identifying and prioritizing barriers to implementation of smart energy city projects in Europe: An empirical approach

    International Nuclear Information System (INIS)

    Mosannenzadeh, Farnaz; Di Nucci, Maria Rosaria; Vettorato, Daniele

    2017-01-01

    Successful implementation of smart energy city projects in Europe is crucial for a sustainable transition of urban energy systems and the improvement of quality of life for citizens. We aim to develop a systematic classification and analysis of the barriers hindering successful implementation of smart energy city projects. Through an empirical approach, we investigated 43 communities implementing smart and sustainable energy city projects under the Sixth and Seventh Framework Programmes of the European Union. Validated through literature review, we identified 35 barriers categorized in policy, administrative, legal, financial, market, environmental, technical, social, and information-and-awareness dimensions. We prioritized these barriers, using a novel multi-dimensional methodology that simultaneously analyses barriers based on frequency, level of impact, causal relationship among barriers, origin, and scale. The results indicate that the key barriers are lacking or fragmented political support on the long term at the policy level, and lack of good cooperation and acceptance among project partners, insufficient external financial support, lack of skilled and trained personnel, and fragmented ownership at the project level. The outcome of the research should aid policy-makers to better understand and prioritize implementation barriers to develop effective action and policy interventions towards more successful implementation of smart energy city projects. - Highlights: • A solid empirical study on the implementation of European smart energy city projects. • We found 35 barriers in nine dimensions; e.g. policy, legal, financial, and social. • We suggested a new multi-dimensional methodology to prioritize barriers. • Lacking or fragmented political support on the long term is a key barrier. • We provided insights for action for project coordinators and policy makers.

  3. Self-organization and forcing templates in coastal barrier response to storms

    Science.gov (United States)

    Lazarus, E.

    2015-12-01

    When a storm event pushes water up and over a coastal barrier, cross-shore flow transports sediment from the barrier face to the back-barrier environment. This natural physical process is called "overwash", and "washover" is the sedimentary deposit it forms. Overwash and washover support critical coastal habitats, and enable barriers to maintain their height and width relative to rising sea level. On developed barrier coasts, overwash constitutes a natural hazard, which sea-level rise will exacerbate. Overwash is also a prerequisite for barrier breaching and coastal flooding. Predicting occurrence and characteristics of overwash and washover has significant societal value. Hazard models typically assume that pre-storm barrier morphology determines how the barrier changes during a storm. However, classic work has documented the absence of a relationship between pre/post-storm topography in some cases, and has also identified rhythmic patterns in washover alongshore. Previous explanations for these spatial patterns have looked to forcing templates, forms that get imprinted in the barrier shape. An alternative explanation is that washover patterns self-organize, emerging from feedbacks between water flow and sediment transport. Self-organization and forcing templates are often framed as mutually exclusive, but patterns likely form across a continuum of conditions. Here, I use data from a new physical experiment to suggest that spatial patterns in washover can self-organize within the limit of a forcing template of some critical "strength", beyond which pre/post-storm morphologies are highly correlated. Quantifying spatial patterns in washover deposits opens exciting questions regarding coastal morphodynamic response to storms. Measurement of relative template strength over extended spatial (and temporal) scales has the potential to improve hazard assessment and prediction, particularly where template strength is low and self-organization dominates barrier change.

  4. Influence of the geometry of protective barriers on the propagation of shock waves

    Science.gov (United States)

    Sochet, I.; Eveillard, S.; Vinçont, J. Y.; Piserchia, P. F.; Rocourt, X.

    2017-03-01

    The protection of industrial facilities, classified as hazardous, against accidental or intentional explosions represents a major challenge for the prevention of personal injury and property damage, which also involves social and economic issues. We consider here the use of physical barriers against the effects of these explosions, which include the pressure wave, the projection of fragments and the thermal flash. This approach can be recommended for the control of major industrial risks, but no specific instructions are available for its implementation. The influence of a protective barrier against a detonation-type explosion is studied in small-scale experiments. The effects of overpressure are examined over the entire path of the shock wave across the barrier and in the downstream zone to be protected. Two series of barrier structures are studied. The first series (A) of experiments investigates two types of barrier geometry with dimensions based on NATO recommendations. These recommendations stipulate that the barrier should be 2 m higher than the charge height, the thickness at the crest should be more than 0.5 m, while its length should be equal to twice the protected structure length and the bank slope should be equivalent to the angle of repose of the soil. The second series (B) of experiments investigates the influence of geometrical parameters of the barrier (thickness at the crest and inclination angles of the front and rear faces) on its protective effects. This project leads to an advance in our understanding of the physical phenomena involved in the propagation of blast waves resulting from an external explosion, in the area around a protective physical barrier. The study focuses on the dimensioning of protective barriers against overpressure effects arising from detonation and shows the advantage of using a barrier with a vertical front or rear face.

  5. Performance evaluation of intermediate cover soil barrier for removal of heavy metals in landfill leachate.

    Science.gov (United States)

    Suzuki, Kazuyuki; Anegawa, Aya; Endo, Kazuto; Yamada, Masato; Ono, Yusaku; Ono, Yoshiro

    2008-11-01

    This pilot-scale study evaluated the use of intermediate cover soil barriers for removing heavy metals in leachate generated from test cells for co-disposed fly ash from municipal solid waste incinerators, ash melting plants, and shredder residue. Cover soil barriers were mixtures of Andisol (volcanic ash soil), waste iron powder, (grinder dust waste from iron foundries), and slag fragments. The cover soil barriers were installed in the test cells' bottom layer. Sorption/desorption is an important process in cover soil bottom barrier for removal of heavy metals in landfill leachate. Salt concentrations such as those of Na, K, and Ca in leachate were extremely high (often greater than 30 gL(-1)) because of high salt content in fly ash from ash melting plants. Concentrations of all heavy metals (nickel, manganese, copper, zinc, lead, and cadmium) in test cell leachates with a cover soil barrier were lower than those of the test cell without a cover soil barrier and were mostly below the discharge limit, probably because of dilution caused by the amount of leachate and heavy metal removal by the cover soil barrier. The cover soil barriers' heavy metal removal efficiency was calculated. About 50% of copper, nickel, and manganese were removed. About 20% of the zinc and boron were removed, but lead and cadmium were removed only slightly. Based on results of calculation of the Langelier saturation index and analyses of core samples, the reactivity of the cover soil barrier apparently decreases because of calcium carbonate precipitation on the cover soil barriers' surfaces.

  6. Design and performance evaluation of a 1000-year evapotranspiration-capillary surface barrier.

    Science.gov (United States)

    Zhang, Zhuanfang Fred; Strickland, Christopher E; Link, Steven O

    2017-02-01

    Surface barrier technology is used to isolate radioactive waste and to reduce or eliminate recharge water to the waste zone for 1000 years or longer. However, the design and evaluation of such a barrier is challenging because of the extremely long design life. After establishing a set of design and performance objectives, a package of design solutions was developed for 1000-year surface barriers over nuclear waste sites. The Prototype Hanford Barrier (PHB) was then constructed in 1994 in the field over an existing waste site as a demonstration. The barrier was tested to evaluate surface-barrier design and performance at the field scale under conditions of enhanced and natural precipitation and of no vegetation. The monitoring data demonstrate that the barrier satisfied nearly all objectives in the past two decades. The PHB far exceeded the Resource Conservation and Recovery Act criteria, functioned in Hanford's semiarid climate, limited drainage to well below the 0.5 mm yr -1 performance criterion, limited runoff, and minimized erosion and bio-intrusion. Given the two-decade record of successful performance and consideration of the processes and mechanisms that could affect barrier stability and hydrology in the future, the results suggest the PHB is very likely to perform for its 1000-year design life. This conclusion is based on two assumptions: (1) the exposed subgrade receives protection against erosion and (2) institutional controls prevent inadvertent human activity at the barrier. The PHB design can serve as the basis for site-specific barriers over waste sites containing underground nuclear waste, uranium mine tailings, and hazardous mine waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Religious culture as a barrier?

    DEFF Research Database (Denmark)

    Agergaard, Sine

    2016-01-01

    Political interventions, media coverage and research often refer to the underrepresentation of ethnic minorities, particularly girls and women, participating in physical activity and organised sports. In both public and academic debates, reference is made to the religious culture as a particular...... barrier to participation in sports among Muslim girls and women. This article aims to provide a counter-narrative by focusing on young Muslim girls who simultaneously practice their religion and sports. The main research question was: How do young Danish Muslim girls align participation in sports...... religion as hegemonic, embodied and dynamic cultural phenomena, the analysis points to the diversity through which Muslim girls and women participate and engage in sports. Finally, the article discusses the extent to which counter-narratives may contribute to changing perspectives on so-called hard...

  8. Modeling of Thermal Barrier Coatings

    Science.gov (United States)

    Ferguson, B. L.; Petrus, G. J.; Krauss, T. M.

    1992-01-01

    The project examined the effectiveness of studying the creep behavior of thermal barrier coating system through the use of a general purpose, large strain finite element program, NIKE2D. Constitutive models implemented in this code were applied to simulate thermal-elastic and creep behavior. Four separate ceramic-bond coat interface geometries were examined in combination with a variety of constitutive models and material properties. The reason for focusing attention on the ceramic-bond coat interface is that prior studies have shown that cracking occurs in the ceramic near interface features which act as stress concentration points. The model conditions examined include: (1) two bond coat coefficient of thermal expansion curves; (2) the creep coefficient and creep exponent of the bond coat for steady state creep; (3) the interface geometry; and (4) the material model employed to represent the bond coat, ceramic, and superalloy base.

  9. KNO scaling

    International Nuclear Information System (INIS)

    Golokhvastov, A.I.; )

    2001-01-01

    A correct version of the KNO scaling of multiplicity distributions is discussed in detail. Some assertions on KNO-scaling violation based on the misinterpretation of experimental data behavior are analyzed. An accurate comparison with experiment is presented for the distributions of negative particles in e + e - annihilation at √S = 3 - 161 GeV, in inelastic pp interactions at √S = 2.4 - 62 GeV and in nucleus-nucleus interactions at p lab = 4.5 - 520 GeV/c per nucleon. The p-bar p data at √S 546 GeV are considered [ru

  10. Developing effective rockfall protection barriers for low energy impacts

    Science.gov (United States)

    Mentani, Alessio; Giacomini, Anna; Buzzi, Olivier; Govoni, Laura; Gottardi, Guido; Fityus, Stephen

    2016-04-01

    Recently, important progresses have been made towards the development of high capacity rockfall barriers (100 kJ - 8000 kJ). The interest of researchers and practitioners is now turning to the development of fences of minor capacity, whose use becomes essential in areas where rockfall events generally have low intensity and the use of high capacity barriers would be accompanied by excessive costs and high environmental impact. Low energy barriers can also provide a cost-effective solution even in areas where high energies events are expected. Results of full-scale tests are vital to any investigation on the behaviour of these structures. An experimental set-up has been developed at The University of Newcastle (AUS), to investigate the response of low energy rockfall barrier prototypes to low energy impacts. The Australian territory, and in particular New South Wales, is in fact characterised by rockfall events of low-to-medium intensity (50 kJ - 500 kJ) and the need of protection structures working within such energy range, is particularly felt [1]. The experiments involved the impact of a test block onto three spans, low energy barrier prototypes, made of steel structural posts, fully fixed at the base, side cables and a steel meshwork constituted by a double twist hexagonal wire net [2]. Test data enabled the development, calibration and assessment of FE models [3], on which non-linear and dynamic analyses have been performed addressing the effect of the block size. Results have shown that the response of the structure is strongly governed by the net. Data from tests conducted on the sole net and on the entire barrier showed in fact a similar trend, different to what typically observed for high capacity barriers, whose behaviour is also led by the presence of uphill cables and brakes. In particular, the numerical analyses have demonstrated a dependence of the net performance on the block size. In particular, a loss of capacity in the order of 50% occurred as the

  11. Application of flexi-wall in noise barriers renewal

    Directory of Open Access Journals (Sweden)

    B. Daee

    2015-12-01

    Full Text Available This paper presents an experimental study on structural performance of an innovative noise barrier consisting of poly-block, light polyurethane foam (LPF and polyurea. This wall system (flexi-wall is intended to be employed as a vertical extension to existing noise barriers (sound walls in an accelerated construction method. To aid in the wall design, several mechanical tests were conducted on LPF specimens and two full-scale walls were then fabricated employing the same LPF material. The full-scale walls were subjected to lateral loading in order to establish their lateral resistance. A cyclic fatigue test was also performed on a full-scale flexi-wall in order to evaluate the performance of the wall under a repetitive loading condition. The results of the experiments indicated the suitability of flexi-wall in accelerated construction and confirmed that the structural performance of the wall system under lateral loading is satisfactory for the sound wall application. The experimental results were discussed and a preliminary design procedure for application of flexi-wall in sound wall applications was also developed.

  12. Effect of Internal and Edge Transport Barriers in ITER Simulations

    International Nuclear Information System (INIS)

    Pianroj, Y.; Onjun, T.; Suwanna, S.; Picha, R.; Poolyarat, N.

    2009-07-01

    Full text: Predictive simulations of ITER with the presence of both an edge transport barrier (ETB) and an internal transport barrier (ITB) are carried out using the BALDUR integrated predictive modeling code. In these simulations, the boundary is taken at the top of the pedestal, where the pedestal values are described using the theory-based pedestal models. These pedestal temperature models are based on three different pedestal width scalings: magnetic and flow shear stabilization (δ α ρ ζ 2 ), flow shear stabilization (δ α Root ρ Rq), and normalized poloidal pressure (δ α R Root βθ, ped). The pedestal width scalings are combined with a pedestal pressure gradient scaling based on ballooning mode limit to predict the pedestal temperature. A version of the semi-empirical Mixed Bohm/gyro Bohm (Mixed B/gB) core transport model that includes ITB effects is used to compute the evolution of plasma profiles and plasma performance, which defined by Fusion Q factor. The results from the cases excluding and including ITB are compared. The preliminary results show the Q value resulted from ITB-excluded simulation is less than the one with ITB included

  13. Identification of Barriers to Stroke Awareness and Risk Factor Management Unique to Hispanics

    Directory of Open Access Journals (Sweden)

    Marina Martinez

    2015-12-01

    Full Text Available Barriers to risk factor control may differ by race/ethnicity. The goal of this study was to identify barriers to stroke awareness and risk factor management unique to Hispanics as compared to non-Hispanic whites (NHWs. We performed a prospective study of stroke patients from an academic Stroke Center in Arizona and surveyed members of the general community. Questionnaires included: the Duke Social Support Index (DSSI, the Multidimensional Health Locus of Control (MHLC Scale, a stroke barriers questionnaire, and a Stroke Awareness Test. Of 145 stroke patients surveyed (72 Hispanic; 73 NHW, Hispanics scored lower on the Stroke Awareness Test compared to NHWs (72.5% vs. 79.1%, p = 0.029. Hispanic stroke patients also reported greater barriers related to medical knowledge, medication adherence, and healthcare access (p < 0.05 for all. Hispanics scored higher on the “powerful others” sub-scale (11.3 vs. 10, p < 0.05 of the MHLC. Of 177 members of the general public surveyed, Hispanics had lower stroke awareness compared to NHWs and tended to have lower awareness than Hispanic stroke patients. These results suggest that Hispanic stroke patients perceive less control over their health, experience more healthcare barriers, and demonstrate lower rates of stroke literacy. Interventions for stroke prevention and education in Hispanics should address these racial/ethnic differences in stroke awareness and barriers to risk factor control.

  14. Magnetized advective accretion flows: formation of magnetic barriers in magnetically arrested discs

    Science.gov (United States)

    Mondal, Tushar; Mukhopadhyay, Banibrata

    2018-05-01

    We discuss the importance of large-scale strong magnetic field in the removal of angular momentum outward, as well as the possible origin of different kinds of magnetic barrier in advective, geometrically thick, sub-Keplerian accretion flows around black holes. The origin of this large-scale strong magnetic field near the event horizon is due to the advection of the magnetic flux by the accreting gas from the environment, say, the interstellar medium or a companion star, because of flux freezing. In this simplest vertically averaged, 1.5-dimensional disc model, we choose the maximum upper limit of the magnetic field, which the disc around a black hole can sustain. In this so called magnetically arrested disc model, the accreting gas either decelerates or faces the magnetic barrier near the event horizon by the accumulated magnetic field depending on the geometry. The magnetic barrier may knock the matter to infinity. We suggest that these types of flow are the building block to produce jets and outflows in the accreting system. We also find that in some cases, when matter is trying to go back to infinity after knocking the barrier, matter is prevented being escaped by the cumulative action of strong gravity and the magnetic tension, hence by another barrier. In this way, magnetic field can lock the matter in between these two barriers and it might be a possible explanation for the formation of episodic jet.

  15. Permeability Barrier Generation in the Martian Lithosphere

    Science.gov (United States)

    Schools, Joe; Montési, Laurent

    2015-11-01

    Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

  16. Scaling satan.

    Science.gov (United States)

    Wilson, K M; Huff, J L

    2001-05-01

    The influence on social behavior of beliefs in Satan and the nature of evil has received little empirical study. Elaine Pagels (1995) in her book, The Origin of Satan, argued that Christians' intolerance toward others is due to their belief in an active Satan. In this study, more than 200 college undergraduates completed the Manitoba Prejudice Scale and the Attitudes Toward Homosexuals Scale (B. Altemeyer, 1988), as well as the Belief in an Active Satan Scale, developed by the authors. The Belief in an Active Satan Scale demonstrated good internal consistency and temporal stability. Correlational analyses revealed that for the female participants, belief in an active Satan was directly related to intolerance toward lesbians and gay men and intolerance toward ethnic minorities. For the male participants, belief in an active Satan was directly related to intolerance toward lesbians and gay men but was not significantly related to intolerance toward ethnic minorities. Results of this research showed that it is possible to meaningfully measure belief in an active Satan and that such beliefs may encourage intolerance toward others.

  17. Barriers to the implementation of research perceived by nurses from Osakidetza.

    Science.gov (United States)

    Cidoncha-Moreno, M Ángeles; Ruíz de Alegría-Fernandez de Retana, Begoña

    To understand the barriers to implementing nursing research findings into practice, as perceived by the nurses working in Osakidetza and to analyze if the workplace factor and time worked affect the perception of these barriers. Cross-sectional study. BARRIERS Scale questionnaire was given to a representative sample of 1,572 Basque Health Service nurses, stratified and randomized, according to scope of work and job responsibility (response rate: 43.76%). According to the research results, the first important barrier was "insufficient time on the job to implement new ideas". Nurses have perceived the organizational factor as the most important barrier in their practice. Nurses in "Special hospital departments" perceived more barriers in the "quality of research" factor than those working in "Primary Care". Years of service showed a slight influence. The nurses stated that external factors related to the organization principally interfered in implementing results into clinical practice. They placed lack of critical reading training second. Working environment and seniority mark differences in the perception of barriers. This study may help to develop strategies for planning training programs to facilitate the use of research in clinical practice, in order to provide quality care. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  18. Artificial barriers prevent genetic recovery of small isolated populations of a low-mobility freshwater fish.

    Science.gov (United States)

    Coleman, R A; Gauffre, B; Pavlova, A; Beheregaray, L B; Kearns, J; Lyon, J; Sasaki, M; Leblois, R; Sgro, C; Sunnucks, P

    2018-01-12

    Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45-120 years ago. We found evidence of small-scale (barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (F ST  = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.

  19. Acyl-CoA binding protein and epidermal barrier function

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Neess, Ditte; Færgeman, Nils J

    2014-01-01

    The acyl-CoA binding protein (ACBP) is a 10kDa intracellular protein expressed in all eukaryotic species and mammalian tissues investigated. It binds acyl-CoA esters with high specificity and affinity and is thought to act as an intracellular transporter of acyl-CoA esters between different...... includes tousled and greasy fur, development of alopecia and scaling of the skin with age. Furthermore, epidermal barrier function is compromised causing a ~50% increase in transepidermal water loss relative to that of wild type mice. Lipidomic analyses indicate that this is due to significantly reduced...

  20. Identifying barriers to emergency care services.

    Science.gov (United States)

    Cannoodt, Luk; Mock, Charles; Bucagu, Maurice

    2012-01-01

    This paper aims to present a review of published evidence of barriers to emergency care, with attention towards both financial and other barriers. With the keywords (financial) accessibility, barriers and emergency care services, citations in PubMed were searched and further selected in the context of the objective of this article. Forty articles, published over a period of 15 years, showed evidence of significant barriers to emergency care. These barriers often tend to persist, despite the fact that the evidence was published many years ago. Several publications stressed the importance of the financial barriers in foregoing or delaying potentially life-saving emergency services, both in poor and rich countries. Other publications report non-financial barriers that prevent patients in need of emergency care (pre-hospital and in-patient care) from seeking care, from arriving in the proper emergency department without undue delay or from receiving proper treatment when they do arrive in these departments. It is clear that timely access to life-saving and disability-preventing emergency care is problematic in many settings. Yet, low-cost measures can likely be taken to significantly reduce these barriers. It is time to make an inventory of these measures and to implement the most cost-effective ones worldwide. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Contaminant containment using polymer gel barriers

    NARCIS (Netherlands)

    Darwish, M.I.M.; Rowe, R.K.; Maarel, van der J.R.C.; Pel, L.; Huinink, H.P.; Zitha, P.L.J.

    2004-01-01

    Polymer gels are well known in the oil industry, but their potential for use as barriers to contaminant transport has not previously received significant study. As a first step, this paper examines the potential for a polyelectrolyte gel to serve as a barrier to the migration of sodium chloride. Two

  2. Storm impacts on small barrier islands

    DEFF Research Database (Denmark)

    Kroon, Aart; Fruergaard, Mikkel

    The shorelines of the Baltic Sea and the inner coastal waters in Denmark consist of many barrier islands. These sandy barrier islands were mainly formed in the Holocene and are still very dynamic. The present day changes in the morphology are dominantly governed by storm waves and associated high...

  3. Engineered Barrier Test Facility status report, 1984

    International Nuclear Information System (INIS)

    Phillips, S.J.; Adams, M.R.; Gilbert, T.W.; Meinhardt, C.C.; Mitchell, R.M.; Waugh, W.J.

    1985-02-01

    This report provides a general summary of activities completed to date at the Hanford Engineered Barrier Test Facility. This facility is used to test and compare construction practices and performance of alternative designs of engineered barrier cover systems. These cover systems are being evaluated for potential use for isolation and confinement of buried waste disposal structures

  4. Nurses' barriers to learning: an integrative review.

    Science.gov (United States)

    Santos, Marion C

    2012-07-01

    This integrative review of the literature describes nurses' barriers to learning. Five major themes emerged: time constraints, financial constraints, workplace culture, access/relevance, and competency in accessing electronic evidence-based practice literature. The nurse educator must address these barriers for the staff to achieve learning and competency.

  5. Barriers to Adult Learning: Bridging the Gap

    Science.gov (United States)

    Falasca, Marina

    2011-01-01

    A fundamental aspect of adult education is engaging adults in becoming lifelong learners. More often than not, this requires removing barriers to learning, especially those relating to the actual organisational or institutional learning process. This article explores some of the main barriers to adult learning discussed in the literature and…

  6. Barriers to adherence in cystic fibrosis

    DEFF Research Database (Denmark)

    Bregnballe, Vibeke; Schiøtz, Peter Oluf

    2012-01-01

    Danish patients with cystic fibrosis aged 14 to 25 years and their parents. Conclusions: The present study showed that the majority of adolescents with CF and their parents experienced barriers to treatment adherence. Patients and parents agreed that the three most common barriers encountered lack...

  7. Barrier Engineered Quantum Dot Infrared Photodetectors

    Science.gov (United States)

    2015-06-01

    251108. 6. Barve, Ajit V., Saumya Sengupta, Jun Oh Kim, John Montoya , Brianna Klein, Mohammad Ali Shirazi, Marziyeh Zamiri et al., "Barrier selection... H . Kim, Z-B. Tian, and Sanjay Krishna. "Barrier Engineered Infrared Photodetectors Based on Type-II InAs/GaSb Strained Layer Superlattices." (2013

  8. Photovoltaic noise barriers; Stille um die Laermschutzwand

    Energy Technology Data Exchange (ETDEWEB)

    Roepcke, I.

    2007-11-30

    Photovoltaic noise barriers are uncommon. There were some demonstration project, but interest died down - in spite of the fact that the EEG specifies the same level of reimbursement for PV noise barriers as for PlV roofs. Recently, efforts have been made to revive the market. (orig.)

  9. K-Basin isolation barrier seal

    International Nuclear Information System (INIS)

    Ruff, E.S.

    1994-10-01

    This report documents various aspects of the design, analysis, procurement, and fabrication of the hydraulic seal on the isolation barriers to be installed in the 100-K Area spent nuclear fuel basin. The isolation barrier is used to keep water in the basin in the event of an earthquake

  10. Israel's Security Barrier: Effects On Operational Factors

    National Research Council Canada - National Science Library

    2004-01-01

    .... The route of the barrier is tinder intense discussion at this time and if implemented as planned by the Sharon government will negatively affect the factors of space and force. The barrier must be constructed along the correct route in order to maximize operational factors.

  11. Fusion barriers in heavy ion collisions

    International Nuclear Information System (INIS)

    Zhu Long; Su Jun; Xie Wenjie; Guo Chenchen; Zhang Donghong; Zhang Fengshou

    2014-01-01

    Study of fusion barrier is very important for people to better understand fusion reactions. In this paper the Improved Isospin-dependent Quantum Molecular Dynamics (ImIQMD) model is introduced firstly. Then the shell correction effects, energy dependence, isospin effects and orientation effects of fusion barrier are studied. The fusion barriers for the fusion reactions "4"0Ca + "4"0Ca, "4"8Ca + "2"0"8Pb, "4"8Ca + "2"0"4Pb and "1"6O + "1"5"4Sm are extracted. The negative shell correction energies lower potential barriers of a certain reaction. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier are also discussed for the system "1"6O + "1"5"4Sm. (authors)

  12. Overcoming Barriers in Working with Families

    Science.gov (United States)

    Heru, Alison M.; Drury, Laura

    2006-01-01

    Objective: The Accreditation Council for Graduate Medical Education and the Residency Review Committee for psychiatry outline the expected competencies for residents. These competencies include working with families. This article describes barriers that residents face when working with families, and offers ways to overcome these barriers. Method:…

  13. Barriers to investment in emerging power markets

    Energy Technology Data Exchange (ETDEWEB)

    Beardsworth, Jr, J J [Hunton and Williams, Richmond, VA (United States)

    1994-12-31

    Investing in private power projects in developing countries is a very different issue from investment in the US or the UK. There are many investment barriers not present in developed nations. Firstly investment barriers need to be identified. Trouble may be encountered with legal authorization; the regulatory framework; government guarantees; fuel supply security; lender protection; labour laws and local commercial restrictions such as profits repatriation, currency convertibility, and taxes. Political barriers may also be encountered in the form of: government commitments and support; funding sources; political unrest; religion; and relationships with other countries. Investment barriers may be minimised by persuading the government to remove any legal barriers; the contract has then to be agreed. Factors in a successful contract include: power purchase agreements; fuel agreements; and implementation agreements. It is vital to have a source of information on local rules and customs, by working with local companies and employing local attorneys.

  14. Engineering kinetic barriers in copper metallization

    International Nuclear Information System (INIS)

    Huang Hanchen; Wei, H.L.; Woo, C.H.; Zhang, X.X.

    2002-01-01

    In metallization processes of integrated circuits, it is desirable to deposit the metal lines (aluminum or copper) fast and at low temperatures. However, the lines (films) usually consist of undesirable columns and voids, because of the absence of sufficient diffusion--a direct result of large kinetic barriers. Following the proposal and realization of the three-dimensional Ehrlich-Schwoebel (3D ES) barrier, we present here a method to engineer this kinetic barrier so as to improve quality of deposited copper films. We deposit copper films by magnetron sputtering, characterize the film structure and texture by using the scanning electron microscope and the x-ray diffraction, respectively. Taking indium as surfactant during copper deposition, we have achieved much better density and bottom coverage of copper filled trenches. The characterizations show that the improvement is the result of the 3D ES barrier reduction caused by indium addition. Engineering the 3D ES barrier therefore leads to improved film quality

  15. Barrier bucket experiment at the AGS

    Directory of Open Access Journals (Sweden)

    M. Fujieda

    1999-12-01

    Full Text Available A barrier bucket experiment with two dedicated barrier cavities was performed at the Brookhaven AGS. One of the barrier cavities was a magnetic alloy (MA–loaded cavity and the other was a ferrite-loaded cavity. They generated a single sine wave with a peak voltage of 40 kV at a repetition rate of 351 kHz. A barrier rf system was established with these cavities and five bunches from the AGS booster were accumulated. A total of 3×10^{13} protons were stored without beam loss, and were successfully rebunched and accelerated. The longitudinal emittance growth was observed during accumulation by the barrier bucket, the blowup factor of which was about 3. The longitudinal mismatch between the rf bucket and the beam bunch was the main reason for the emittance growth. The potential distortions by beam loading of the ferrite cavity and the overshooting voltage of the MA cavity disturbed the smooth debunching.

  16. Mucus as a Barrier to Drug Delivery

    DEFF Research Database (Denmark)

    Bøgh, Marie; Nielsen, Hanne Mørck

    2015-01-01

    Viscoelastic mucus lines all mucosal surfaces of the body and forms a potential barrier to mucosal drug delivery. Mucus is mainly composed of water and mucins; high-molecular weight glycoproteins forming an entangled network. Consequently, mucus forms a steric barrier and due to its negative charge...... barrier to drug delivery. Current knowledge of mucus characteristics and barrier properties, as achieved by state-of-the-art methodologies, is the topic of this MiniReview emphasizing the gastrointestinal mucus and an overall focus on oral drug delivery. Cell culture-based in vitro models are well......, studies of peptide and protein drug diffusion in and through mucus and studies of mucus-penetrating nanoparticles are included to illustrate the mucus as a potentially important barrier to obtain sufficient bioavailability of orally administered drugs, and thus an important parameter to address...

  17. Tunnelling through a Gaussian random barrier

    International Nuclear Information System (INIS)

    Bezak, Viktor

    2008-01-01

    A thorough analysis of the tunnelling of electrons through a laterally inhomogeneous rectangular barrier is presented. The barrier height is defined as a statistically homogeneous Gaussian random function. In order to simplify calculations, we assume that the electron energy is low enough in comparison with the mean value of the barrier height. The randomness of the barrier height is defined vertically by a constant variance and horizontally by a finite correlation length. We present detailed calculations of the angular probability density for the tunnelled electrons (i.e. for the scattering forwards). The tunnelling manifests a remarkably diffusive character if the wavelength of the electrons is comparable with the correlation length of the barrier

  18. Barriers in the energy of deformed nuclei

    Directory of Open Access Journals (Sweden)

    V. Yu. Denisov

    2014-06-01

    Full Text Available Interaction energy between two nuclei considering to their deformations is studied. Coulomb and nuclear in-teraction energies, as well as the deformation energies of both nuclei, are taken into account at evaluation of the interaction energy. It is shown that the barrier related to the interaction energy of two nuclei depends on the de-formations and the height of the minimal barrier is evaluated. It is obtained that the heavier nucleus-nucleus sys-tems have large deformation values at the lowest barrier. The difference between the barrier between spherical nuclei and the lowest barrier between deformed nuclei increases with the mass and the charge of the interacting nuclei.

  19. Consumer Mobile Health Apps: Current State, Barriers, and Future Directions.

    Science.gov (United States)

    Kao, Cheng-Kai; Liebovitz, David M

    2017-05-01

    This paper discusses the current state, barriers, and future directions of consumer-facing applications (apps). There are currently more than 165,000 mobile health apps publicly available in major app stores, the vast majority of which are designed for patients. The top 2 categories are wellness management and disease management apps, whereas other categories include self-diagnosis, medication reminder, and electronic patient portal apps. Apps specific to physical medicine and rehabilitation also are reviewed. These apps have the potential to provide low-cost, around-the-clock access to high-quality, evidence-based health information to end users on a global scale. However, they have not yet lived up to their potential due to multiple barriers, including lack of regulatory oversight, limited evidence-based literature, and concerns of privacy and security. The future directions may consist of improving data integration into the health care system, an interoperable app platform allowing access to electronic health record data, cloud-based personal health record across health care networks, and increasing app prescription by health care providers. For consumer mobile health apps to fully contribute value to health care delivery and chronic disease management, all stakeholders within the ecosystem must collaborate to overcome the significant barriers. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  20. Double internal transport barrier triggering mechanism in tokamak plasmas

    International Nuclear Information System (INIS)

    Dong, Jiaqi; Mou, Zongze; Long, Yongxing; Mahajan, Swadesh M.

    2004-01-01

    Sheared flow layers created by energy released in magnetic reconnection processes are studied with the magneto hydrodynamics (MHD), aimed at internal transport barrier (ITB) dynamics. The double tearing mode induced by electron viscosity is investigated and proposed as a triggering mechanism for double internal transport barrier (DITB) observed in tokamak plasmas with non-monotonic safety factor profiles. The quasi-linear development of the mode is simulated and the emphasis is placed on the structure of sheared poloidal flow layers formed in the vicinity of the magnetic islands. For viscosity double tearing modes, it is shown that the sheared flows induced by the mode may reach the level required by the condition for ITB formation. Especially, the flow layers are found to form just outside the magnetic islands. The scaling of the generated velocity with plasma parameters is given. Possible explanation for the experimental observations that the preferential formation of transport barriers in the proximity of low order rational surface is discussed. (author)

  1. Overcoming Barriers to Successfully Commercializing Carbon Dioxide Utilization

    Directory of Open Access Journals (Sweden)

    Marvin Kant

    2017-09-01

    Full Text Available The successful transition to a low-carbon economy hinges on innovative solutions and collaborative action on a global scale. Sustainable entrepreneurship is thereby recognized as a key driver in the creation and transformation of ecologically and socially sustainable economic systems. The purpose of this article is to contribute to this topic by understanding commercialization barriers for strong sustainability-oriented new technology ventures and to derive recommendations to overcome them. A qualitative multilevel approach is applied to identify barriers and drivers within the internal dynamic capabilities of the organization and within the organization’s external stakeholders. A model of barriers has been developed based on semi-structured interviews with new carbon dioxide utilization ventures and associated industry players in Canada, the USA, and the European Economic Area. Resulting recommendations to facilitate the (re-design of a dedicated support system are proposed on four levels: (a actors, (b resources, (c institutional settings, and (d the coordination of the support system.

  2. Barriers in the path of yoga practice: An online survey

    Directory of Open Access Journals (Sweden)

    H V Dayananda

    2014-01-01

    Full Text Available Context: Clinical benefits of yoga have been well explored, but factors contributing to adherence to regular yoga practice are not well studied. Aims: To study the factors influencing adherence to yoga practices on those participants who have completed 1-month Yoga Instructors′ course from a yoga university. Settings and Design: Online survey was conducted on participants who had finished 1-month Yoga Instructors′ course at a yoga university. Materials and Methods: Online survey was conducted using Survey Monkey web portal with response rate of 42.5%. A total of 1355 participants were approached. Demographic items and a checklist of 21 items on a 5-point likert scale were prepared based on traditional yoga texts. A few items to assess modern lifestyle barriers were also included. Statistical Analysis: One-sample proportion test with chi square statistics was used for analysis. Results: Irregularity in lifestyle, family commitments, and occupational commitments are perceived as significant strong barriers. Dullness, excessive talking, strictly adhering to rules, laziness, physical and mental overexertion, fickleness and wandering of mind, unsteadiness of mind, procrastination, and oversleeping are considered as significant barriers of moderate nature. Conclusions: Modern lifestyle is the major challenge for yoga practitioners to adhere to regular practice of yoga. To address this, attention is required in strengthening the lifestyle management and the spiritual dimension of yoga practice as the spiritual component seems to be side-tracked.

  3. Nuclear scales

    International Nuclear Information System (INIS)

    Friar, J.L.

    1998-01-01

    Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the π-γ force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted

  4. Nuclear scales

    Energy Technology Data Exchange (ETDEWEB)

    Friar, J.L.

    1998-12-01

    Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

  5. Institutional distributed energy interconnection barriers

    International Nuclear Information System (INIS)

    Castelaz, S.A.

    2002-01-01

    This PowerPoint presentation provided an introduction to Encorp Inc., a leading provider of network technology and infrastructure management solutions for the distributed energy market. Encorp develops and markets software and hardware technology solutions for communications, control and networking of distributed energy. It is developing and implementing real-time, distributed energy-focused solutions for a wide variety of applications through new products and services which are technology neutral, and easily networked. Encorp controls more than 500 MW of distributed power with a total of 127 customers. This paper reviewed 3 barriers (regulatory, contractual/tariffs, and business practices) based on US experience. The challenge remaining is to determine if microgrids can be used effectively, and to determine the limitations of bi-directional power flows. The key issues regarding how end-users can share the costs and maximize on the benefits of distributed energy resources include: standby service charges, departing load charges, regulatory uncertainty, rate class degradation, lack of incentives for utility cost reduction, and lack of ability to create experimental tariffs. tabs., figs

  6. Tunnel junctions with multiferroic barriers

    Science.gov (United States)

    Gajek, Martin; Bibes, Manuel; Fusil, Stéphane; Bouzehouane, Karim; Fontcuberta, Josep; Barthélémy, Agnès; Fert, Albert

    2007-04-01

    Multiferroics are singular materials that can exhibit simultaneously electric and magnetic orders. Some are ferroelectric and ferromagnetic and provide the opportunity to encode information in electric polarization and magnetization to obtain four logic states. However, such materials are rare and schemes allowing a simple electrical readout of these states have not been demonstrated in the same device. Here, we show that films of La0.1Bi0.9MnO3 (LBMO) are ferromagnetic and ferroelectric, and retain both ferroic properties down to a thickness of 2nm. We have integrated such ultrathin multiferroic films as barriers in spin-filter-type tunnel junctions that exploit the magnetic and ferroelectric degrees of freedom of LBMO. Whereas ferromagnetism permits read operations reminiscent of magnetic random access memories (MRAM), the electrical switching evokes a ferroelectric RAM write operation. Significantly, our device does not require the destructive ferroelectric readout, and therefore represents an advance over the original four-state memory concept based on multiferroics.

  7. 49 CFR 587.18 - Dimensions of fixed rigid barrier.

    Science.gov (United States)

    2010-10-01

    ... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) DEFORMABLE BARRIERS Offset Deformable Barrier § 587.18 Dimensions of fixed rigid barrier. (a) The fixed rigid barrier has a mass of not... 49 Transportation 7 2010-10-01 2010-10-01 false Dimensions of fixed rigid barrier. 587.18 Section...

  8. High density internal transport barriers for burning plasma operation

    International Nuclear Information System (INIS)

    Pericoli Ridolfini, V.

    2005-01-01

    One of the proposed ITER scenarios foresees the creation and sustainment of an internal transport barrier (ITB) in order to improve the confinement properties of the hot core plasma. The more stringent requests are: the ITB must be sustained with electron heating only with no or very small external momentum source, the strong collisional coupling at the envisaged density (line average >1.0 1020 m-3) must not prevent the barrier existence, the bootstrap current created by the large induced gradients must have a radial profile consistent with that requested by the barrier creation and sustainment. To all these items the studies carried out in FTU in the same density range (ne0 ?1.5 1020 m-3) provide encouraging prospects. With pure electron heating and current drive (LH+ECH) steady electron barrier are generated and maintained with central e- temperature >5.0 keV. Almost full CD conditions are established with a bootstrap current close to 25% of the total and well aligned with that driven by the LH waves and responsible for the barrier building. The clear change in the density fluctuations close to the ITB radius, observed by reflectometry, indicates stabilization of turbulence that is consistent with the drop of the thermal electron diffusivity inside the ITB to very low values, ?e<0.5 m2/s estimated by the transport analysis. The 10 fold neutron rate increase testifies a significant collisional ion heating, even though usually ?Ti0/Ti0 does not exceed 40%, because the e--i + equipartition time, always 4-5 times longer than the energy confinement time, does not allow thermal equilibrium with electrons to be attained. The ion thermal diffusivity inside the barrier must be lowered to the neoclassical level to account for the observed Ti(r) profiles, clearly indicating at least a non-degraded ion transport. The global confinement in turn improves by 1.6 times above the FTU L-scaling. The ITB radius can be controlled by varying the LH power deposition profile that is

  9. Astrocyte–endothelial interactions and blood–brain barrier permeability*

    Science.gov (United States)

    Abbott, N Joan

    2002-01-01

    The blood–brain barrier (BBB) is formed by brain endothelial cells lining the cerebral microvasculature, and is an important mechanism for protecting the brain from fluctuations in plasma composition, and from circulating agents such as neurotransmitters and xenobiotics capable of disturbing neural function. The barrier also plays an important role in the homeostatic regulation of the brain microenvironment necessary for the stable and co-ordinated activity of neurones. The BBB phenotype develops under the influence of associated brain cells, especially astrocytic glia, and consists of more complex tight junctions than in other capillary endothelia, and a number of specific transport and enzyme systems which regulate molecular traffic across the endothelial cells. Transporters characteristic of the BBB phenotype include both uptake mechanisms (e.g. GLUT-1 glucose carrier, L1 amino acid transporter) and efflux transporters (e.g. P-glycoprotein). In addition to a role in long-term barrier induction and maintenance, astrocytes and other cells can release chemical factors that modulate endothelial permeability over a time-scale of seconds to minutes. Cell culture models, both primary and cell lines, have been used to investigate aspects of barrier induction and modulation. Conditioned medium taken from growing glial cells can reproduce some of the inductive effects, evidence for involvement of diffusible factors. However, for some features of endothelial differentiation and induction, the extracellular matrix plays an important role. Several candidate molecules have been identified, capable of mimicking aspects of glial-mediated barrier induction of brain endothelium; these include TGFβ, GDNF, bFGF, IL-6 and steroids. In addition, factors secreted by brain endothelial cells including leukaemia inhibitory factor (LIF) have been shown to induce astrocytic differentiation. Thus endothelium and astrocytes are involved in two-way induction. Short-term modulation of brain

  10. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    Science.gov (United States)

    Ansari, Walid El; Lovell, Geoff

    2009-01-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20–27 years) and older (28–35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants’ number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women’s total exercise barrier scores. Number of children explained ≈25% and ≈30% of the variance of younger and older women’s total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20–35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention. PMID:19440527

  11. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    Directory of Open Access Journals (Sweden)

    Geoff Lovell

    2009-04-01

    Full Text Available A survey of 100 women in the south of London, United Kingdom (UK compared exercise barrier intensities between non-exercising younger (20-27 years and older (28-35 years adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement. Participants’ number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women’s total exercise barrier scores. Number of children explained »25% and »30% of the variance of younger and older women’s total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20-35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention.

  12. Barriers to exercise in younger and older non-exercising adult women: a cross sectional study in London, United Kingdom.

    Science.gov (United States)

    El Ansari, Walid; Lovell, Geoff

    2009-04-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20-27 years) and older (28-35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants' number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women's total exercise barrier scores. Number of children explained approximately 25% and approximately 30% of the variance of younger and older women's total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20-35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention.

  13. Large-scale coastal impact induced by a catastrophic storm

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Johannessen, Peter N

    breaching. Our results demonstrate that violent, millennial-scale storms can trigger significant large-scale and long-term changes on barrier coasts, and that coastal changes assumed to take place over centuries or even millennia may occur in association with a single extreme storm event....

  14. Temperature dependence of fluctuation time scales in spin glasses

    DEFF Research Database (Denmark)

    Kenning, Gregory G.; Bowen, J.; Sibani, Paolo

    2010-01-01

    Using a series of fast cooling protocols we have probed aging effects in the spin glass state as a function of temperature. Analyzing the logarithmic decay found at very long time scales within a simple phenomenological barrier model, leads to the extraction of the fluctuation time scale of the s...

  15. Perceived Exercise Benefits and Barriers of Non-Exercising Female University Students in the United Kingdom

    Directory of Open Access Journals (Sweden)

    John K. Parker

    2010-03-01

    Full Text Available Many individuals do not engage in sufficient physical activity due to low perceived benefits and high perceived barriers to exercise. Given the increasing incidence of obesity and obesity related health disorders, this topic requires further exploration. We used the Exercise Benefits/Barriers Scale to assess perceived benefit and barrier intensities to exercise in 200 non-exercising female university students (mean age 19.3 years, SD = 1.06 in the UK. Although our participants were selected because they self reported themselves to be non-exercising, however they reported significantly higher perceived benefits from exercise than perceived barriers to exercise [t(199 = 6.18, p < 0.001], and their perceived benefit/barrier ratio was 1.33. The greatest perceived benefit from exercise was physical performance followed by the benefits of psychological outlook, preventive health, life enhancement, and then social interaction. Physical performance was rated significantly higher than all other benefits. Psychological outlook and preventive health were not rated significantly different, although both were significantly higher than life enhancement and social interaction. Life enhancement was also rated significantly higher than social interaction. The greatest perceived barrier to exercise was physical exertion, which was rated significantly higher than time expenditure, exercise milieu, and family discouragement barriers. Implications from this investigation for the design of physical activity programmes include the importance, for females, of a perception of high benefit/barrier ratio that could be conducive to participation in exercise. Applied interventions need to assist female students to ‘disengage’ from or overcome any perceived ‘unpleasantness’ of physical exertion during physical activity (decrease their perceived barriers, and to further highlight the multiple health and other benefits of regular exercising (increase their perceived

  16. Barriers to implementing infection prevention and control guidelines during crises: experiences of health care professionals.

    Science.gov (United States)

    Timen, Aura; Hulscher, Marlies E J L; Rust, Laura; van Steenbergen, Jim E; Akkermans, Reinier P; Grol, Richard P T M; van der Meer, Jos W M

    2010-11-01

    Communicable disease crises can endanger the health care system and often require special guidelines. Understanding reasons for nonadherence to crisis guidelines is needed to improve crisis management. We identified and measured barriers and conditions for optimal adherence as perceived by 4 categories of health care professionals. In-depth interviews were performed (n = 26) to develop a questionnaire for a cross-sectional survey of microbiologists (100% response), infection preventionists (74% response), public health physicians (96% response), and public health nurses (82% response). The groups were asked to appraise barriers encountered during 4 outbreaks (severe acute respiratory syndrome [SARS], Clostridium difficile ribotype 027, rubella, and avian influenza) according to a 5-point Likert scale. When at least 33% of the participants responded "strongly agree," "agree," or "rather agree than disagree," a barrier was defined as "often experienced." The common ("generic") barriers were included in a univariate and multivariate model. Barriers specific to the various groups were studied as well. Crisis guidelines were found to have 4 generic barriers to adherence: (1) lack of imperative or precise wording, (2) lack of easily identifiable instructions specific to each profession, (3) lack of concrete performance targets, and (4) lack of timely and adequate guidance on personal protective equipment and other safety measures. The cross-sectional study also yielded profession-specific sets of often-experienced barriers. To improve adherence to crisis guidelines, the generic barriers should be addressed when developing guidelines, irrespective of the infectious agent. Profession-specific barriers require profession-specific strategies to change attitudes, ensure organizational facilities, and provide an adequate setting for crisis management. Copyright © 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights

  17. Preferences for and Barriers to Formal and Informal Athletic Training Continuing Education Activities

    Science.gov (United States)

    Armstrong, Kirk J.; Weidner, Thomas G.

    2011-01-01

    Context: Our previous research determined the frequency of participation and perceived effect of formal and informal continuing education (CE) activities. However, actual preferences for and barriers to CE must be characterized. Objective: To determine the types of formal and informal CE activities preferred by athletic trainers (ATs) and barriers to their participation in these activities. Design: Cross-sectional study. Setting: Athletic training practice settings. Patients or Other Participants: Of a geographically stratified random sample of 1000 ATs, 427 ATs (42.7%) completed the survey. Main Outcome Measure(s): As part of a larger study, the Survey of Formal and Informal Athletic Training Continuing Education Activities (FIATCEA) was developed and administered electronically. The FIATCEA consists of demographic characteristics and Likert scale items (1 = strongly disagree, 5 = strongly agree) about preferred CE activities and barriers to these activities. Internal consistency of survey items, as determined by Cronbach α, was 0.638 for preferred CE activities and 0.860 for barriers to these activities. Descriptive statistics were computed for all items. Differences between respondent demographic characteristics and preferred CE activities and barriers to these activities were determined via analysis of variance and dependent t tests. The α level was set at .05. Results: Hands-on clinical workshops and professional networking were the preferred formal and informal CE activities, respectively. The most frequently reported barriers to formal CE were the cost of attending and travel distance, whereas the most frequently reported barriers to informal CE were personal and job-specific factors. Differences were noted between both the cost of CE and travel distance to CE and all other barriers to CE participation (F1,411 = 233.54, P formal CE activities. The same barriers (eg, cost, travel distance) to formal CE appeared to be universal to all ATs. Informal CE was

  18. Perceived gender-based barriers to careers in academic surgery.

    Science.gov (United States)

    Cochran, Amalia; Hauschild, Tricia; Elder, William B; Neumayer, Leigh A; Brasel, Karen J; Crandall, Marie L

    2013-08-01

    Women represent roughly 50% of US medical students and one third of US surgery residents. Within academic surgery departments, however, women are disproportionately underrepresented, particularly at senior levels. The aim of this study was to test the hypothesis that female surgeons perceive different barriers to academic careers relative to their male colleagues. A modified version of the Career Barriers Inventory-Revised was administered to senior surgical residents and early-career surgical faculty members at 8 academic medical centers using an online survey tool. Likert-type scales were used to measure respondents' agreement with each survey item. Fisher's exact test was used to identify significant differences on the basis of gender. Respondents included 70 women (44 residents, 26 faculty members) and 84 men (41 residents, 43 faculty members). Women anticipated or perceived active discrimination in the form of being treated differently and experiencing negative comments about their sex, findings that differed notably from those for male counterparts. Sex-based negative attitudes inhibited the career aspirations of female surgeons. The presence of overt and implicit bias resulted in a sense that sex is a barrier to female surgeons' career development in academic surgery. No differences were observed between male and female respondents with regard to career preparation or structural barriers. Female academic surgeons experience challenges that are perceived to differ from their male counterparts. Women who participated in this study reported feeling excluded from the dominant culture in departments of surgery. This study may help guide transformative initiatives within academic surgery departments. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Validation of the Performance of Engineered Barriers

    International Nuclear Information System (INIS)

    Choi, Jongwon; Cho, Wonjin; Kwon, Sangki

    2012-04-01

    To study the thermal-hydro-mechanical (THM) and thermal-hydro-mechanical-chemical (THMC) behavior of engineered barrier system (EBS), the engineering scale experiments, KENTEX and KENTEX-C were conducted to investigate THM and THMC behavior in the buffer. The computer modelling and simulation programmes were developed to analyze the distribution of temperature, water content, total pressure and the measured data on the migration behavior of anion and cation. In-situ heater test were performed to investigate the effect of the ventilation, thermal characteristics of EDZ, and effect of the anisotropy of rock mass and joint in addition to the investigation of the thermo-mechanical behavior in rock mass. The geophysics exploration and in-situ field tests were carried out to investigate the range of EDZ and its effects on the mechanical properties of rock. Subsequently, crack propagation characteristics and dynamic material properties of jointed rock mass in KURT were measured. Concurrently, the in-situ experiments were performed in the KURT to investigate the change of hydraulic properties in EDZ. The stainless steel molds are manufactured to fabricate the buffer blocks with various shapes. The experiments are carried out to check the mechanical properties, the workability for installation of the fabricated blocks and to investigate the resaturation processes. The state of the technology on application of cementitious materials to the HLW repository was analysed and the optimized low-pH cement recipe was obtained. And the material properties of low-pH and high-pH cement grouts were evaluated based on the grout recipes of ONKALO in Finland. The KURT was operated, and the various technical supports were provided to the in-situ experiments which were carried at KURT

  20. The perceived benefits and barriers to exercise participation in persons with multiple sclerosis.

    Science.gov (United States)

    Stroud, Nicole; Minahan, Clare; Sabapathy, Surendran

    2009-01-01

    The purpose of this study was to examine the perceived benefits and barriers to exercise participation in persons with multiple sclerosis (MS). A cross-sectional postal survey comprised of 93 adults with MS was conducted. Participants completed the Exercise Benefits and Barriers Scale (EBBS), Spinal Cord Injury Exercise Self-Efficacy Scale (EXSE), Multiple Sclerosis Impact Scale, Disease Steps Scale and International Physical Activity Questionnaire. Forty-three percent of the participants were classified as exercising individuals (EX group) as compared with non-exercising individuals (non-EX group). Participants in the EX group reported significantly higher scores on the EBBS and EXSE. Items related to physical performance and personal accomplishment were cited as the greatest perceived benefits to exercise participation and those items related to physical exertion as the greatest perceived barriers to both the EX and non-EX groups. When compared with previous studies conducted in the general population, the participants in the present study reported different perceived barriers to exercise participation. Furthermore, awareness of the benefits of physical activity is not sufficient to promote exercise participation in persons with MS. Perceived exercise self-efficacy is shown to play an important role in promoting exercise participation in persons with MS.

  1. Computational images of internal-transport-barrier oscillations in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bizarro, J.P S. [Inst Super Tecn, Ctr Fusao Nucl, EURATOM Assoc, P-1049001 Lisbon (Portugal); Litaudon, X.L. [CEA Cadarache, Dept Rech Fus Controlee, EURATOM Assoc, F-13108 St Paul Les Durance (France); Tala, T.J.J. [Assoc Euratom Tekes, FIN-02044 Espoo (Finland); JET EFDA Contributors [Culham Sci Ctr, Abingdon OX14 3DB, Oxon (United Kingdom)

    2008-07-01

    A well-known benchmarked code, where a Bohm-gyro-Bohm transport model is complemented with an empirical scaling for the dynamics of internal transport barriers (ITBs), is used to model the ITB oscillations that are often seen in advanced tokamak scenarios with a dominant fraction of bootstrap current. (authors)

  2. Magnetron sputtered gadolinia-doped ceria diffusion barriers for metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Sønderby, Steffen; Klemensø, Trine; Christensen, Bjarke H.

    2014-01-01

    Gadolinia-doped ceria (GDC) thin films are deposited by reactive magnetron sputtering in an industrial-scale setup and implemented as barrier layers between the cathode and electrolyte in metal-based solid oxide fuel cells consisting of a metal support, an electrolyte of ZrO2 co-doped with Sc2O3...

  3. Factors in Overcoming Barriers to Implementing Co-management in British Columbia Salmon Fisheries

    Directory of Open Access Journals (Sweden)

    Evelyn Pinkerton

    1999-12-01

    Full Text Available Ten years of research and efforts to implement co-management in British Columbia fisheries have demonstrated that we lack neither good models nor the political will in communities to design and test local and regional institutions for successful involvement in various aspects of management. The barriers lie rather in the distrust and resistance of management agencies and the lack of broadly organized political support. The nature of the barriers and some of the elements of a successful approach to overcoming them are identified and discussed. The analysis is focused around the barriers encountered by two differently situated fishing communities or regions that have launched conservation initiatives through cooperation between local aboriginal and nonaboriginal fishing groups. In attempting to overcome the political barriers, the communities seek to develop expertise in selective fishing technology for more sustainable harvest, principled multi-stakeholder negotiation, marketing, shared databases, and preliminary ecosystem monitoring. The communities exemplify small- and medium-scale bottom-up approaches to adaptive management. The analysis shows the key and possibly unique contributions of processes at these levels, and suggests how they can be scaled up and linked to processes at other levels. Both types of analysis are largely missing in adaptive management theory, which has tended to focus on larger scale processes and to dismiss the potential of smaller scale ones to transform, expand, and link. This analysis focuses on salmon (Oncorhynchus spp. fisheries of British Columbia, Canada, but the literature suggests that the findings have far broader applicability.

  4. Perceptions of risk and barriers to cervical cancer screening at Moi ...

    African Journals Online (AJOL)

    Background: Affordable screening cervical cancer methods using visual inspection with acetic acid (VIA) and with Lugol's iodine (VILI) are being developed. Scaling up of screening services requires an understanding of the user perceptions about screening. Objectives: Determine the perceptions of risk and barriers to ...

  5. Barriers to installing innovative energy systems in existing housing stock identified

    NARCIS (Netherlands)

    Hoppe, Thomas

    2013-01-01

    Several barriers to upgrading existing social housing with innovative energy systems (IES) have been identified by a study of eight large-scale renovation projects in the Netherlands. These include a lack of trust between stakeholders, opposition from tenants on grounds of increased costs or delays,

  6. Model assessment of protective barrier designs

    International Nuclear Information System (INIS)

    Fayer, M.J.; Conbere, W.; Heller, P.R.; Gee, G.W.

    1985-11-01

    A protective barrier is being considered for use at the Hanford site to enhance the isolation of previously disposed radioactive wastes from infiltrating water, and plant and animal intrusion. This study is part of a research and development effort to design barriers and evaluate their performance in preventing drainage. A fine-textured soil (the Composite) was located on the Hanford site in sufficient quantity for use as the top layer of the protective barrier. A number of simulations were performed by Pacific Northwest Laboratory to analyze different designs of the barrier using the Composite soil as well as the finer-textured Ritzville silt loam and a slightly coarser soil (Coarse). Design variations included two rainfall rates (16.0 and 30.1 cm/y), the presence of plants, gravel mixed into the surface of the topsoil, an impermeable boundary under the topsoil, and moving the waste form from 10 to 20 m from the barrier edge. The final decision to use barriers for enhanced isolation of previously disposed wastes will be subject to decisions resulting from the completion of the Hanford Defense Waste Environmental Impact Statement, which addresses disposal of Hanford defense high-level and transuranic wastes. The one-dimensional simulation results indicate that each of the three soils, when used as the top layer of the protective barrier, can prevent drainage provided plants are present. Gravel amendments to the upper 30 cm of soil (without plants) reduced evaporation and allowed more water to drain

  7. Numerical simulations of capillary barrier field tests

    International Nuclear Information System (INIS)

    Morris, C.E.; Stormont, J.C.

    1997-01-01

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior

  8. Shakeoff Ionization near the Coulomb Barrier Energy

    Science.gov (United States)

    Sharma, Prashant; Nandi, T.

    2017-11-01

    We measure the projectile K x-ray spectra as a function of the beam energies around the Coulomb barrier in different collision systems. The energy is scanned in small steps around the barrier aiming to explore the nuclear effects on the elastically scattered projectile ions. The variation of the projectile x-ray energy with the ion-beam energies exhibits an unusual increase in between the interaction barrier and fusion barrier energies. This additional contribution to the projectile ionization can be attributed to the shakeoff of outer-shell electrons of the projectile ions due to the sudden nuclear recoil (˜10-21 sec ) caused by the attractive nuclear potential, which gets switched on near the interaction barrier energy. In the sudden approximation limit, the theoretical shakeoff probability calculation due to the nuclear recoil explains the observed data well. In addition to its fundamental interest, such processes can play a significant role in dark matter detection through the possible mechanism of x-ray emissions, where the weakly interacting massive particle-nucleus elastic scattering can lead to the nuclear-recoil-induced inner-shell vacancy creations. Furthermore, the present work may provide new prospects for atomic physics research at barrier energies as well as provide a novel technique to perform barrier distribution studies for two-body systems.

  9. Overcoming natural replication barriers: differential helicase requirements.

    Science.gov (United States)

    Anand, Ranjith P; Shah, Kartik A; Niu, Hengyao; Sung, Patrick; Mirkin, Sergei M; Freudenreich, Catherine H

    2012-02-01

    DNA sequences that form secondary structures or bind protein complexes are known barriers to replication and potential inducers of genome instability. In order to determine which helicases facilitate DNA replication across these barriers, we analyzed fork progression through them in wild-type and mutant yeast cells, using 2-dimensional gel-electrophoretic analysis of the replication intermediates. We show that the Srs2 protein facilitates replication of hairpin-forming CGG/CCG repeats and prevents chromosome fragility at the repeat, whereas it does not affect replication of G-quadruplex forming sequences or a protein-bound repeat. Srs2 helicase activity is required for hairpin unwinding and fork progression. Also, the PCNA binding domain of Srs2 is required for its in vivo role of replication through hairpins. In contrast, the absence of Sgs1 or Pif1 helicases did not inhibit replication through structural barriers, though Pif1 did facilitate replication of a telomeric protein barrier. Interestingly, replication through a protein barrier but not a DNA structure barrier was modulated by nucleotide pool levels, illuminating a different mechanism by which cells can regulate fork progression through protein-mediated stall sites. Our analyses reveal fundamental differences in the replication of DNA structural versus protein barriers, with Srs2 helicase activity exclusively required for fork progression through hairpin structures.

  10. Resolving the mystery of transport within internal transport barriers

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, G. M.; Belli, E. A.; Candy, J.; Waltz, R. E.; Greenfield, C. M.; Lao, L. L.; Smith, S. P. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Kinsey, J. E. [CompX, P.O. Box 2672, Del Mar, California 92014-5672 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Chrystal, C. [University of California-San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States)

    2014-05-15

    The Trapped Gyro-Landau Fluid (TGLF) quasi-linear model [G. M. Staebler, et al., Phys. Plasmas 12, 102508 (2005)], which is calibrated to nonlinear gyrokinetic turbulence simulations, is now able to predict the electron density, electron and ion temperatures, and ion toroidal rotation simultaneously for internal transport barrier (ITB) discharges. This is a strong validation of gyrokinetic theory of ITBs, requiring multiple instabilities responsible for transport in different channels at different scales. The mystery of transport inside the ITB is that momentum and particle transport is far above the predicted neoclassical levels in apparent contradiction with the expectation from the theory of suppression of turbulence by E×B velocity shear. The success of TGLF in predicting ITB transport is due to the inclusion of ion gyro-radius scale modes that become dominant at high E×B velocity shear and to improvements to TGLF that allow momentum transport from gyrokinetic turbulence to be faithfully modeled.

  11. Permanent isolation surface barrier development plan

    International Nuclear Information System (INIS)

    Wing, N.R.

    1994-01-01

    The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no open-quotes provenclose quotes long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems

  12. Permanent isolation surface barrier development plan

    Energy Technology Data Exchange (ETDEWEB)

    Wing, N.R.

    1994-01-01

    The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no {open_quotes}proven{close_quotes} long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems.

  13. Collisions between heavy nuclei near the barrier

    International Nuclear Information System (INIS)

    Henning, W.

    1988-05-01

    Detailed information has recently become available on the reaction behavior in very heavy nuclear systems close to the Coulomb barrier. Starting from an experimental study of the distribution of the reaction strength above and below the barrier, the dominant reaction channels of quasi-elastic and strongly-damped processes are examined. With decreasing incident energy, the sub-barrier collisions are increasingly dominated by quasi-elastic processes. From the division of internal excitation energy, new information is obtained on the nature of the dissipative processes. (orig.)

  14. Frozen soil barrier technology. Innovative technology summary report

    International Nuclear Information System (INIS)

    1995-04-01

    The technology of using refrigeration to freeze soils has been employed in large-scale engineering projects for a number of years. This technology bonds soils to give load-bearing strength during construction; to seal tunnels, mine shafts, and other subsurface structures against flooding from groundwater; and to stabilize soils during excavation. Examples of modern applications include several large subway, highway, and water supply tunnels. Ground freezing to form subsurface frozen soil barriers is an innovative technology designed to contain hazardous and radioactive contaminants in soils and groundwater. Frozen soil barriers that provide complete containment (open-quotes Vclose quotesconfiguration) are formed by drilling and installing refrigerant piping (on 8-ft centers) horizontally at approximately 45 degrees angles for sides and vertically for ends and then recirculating an environmentally safe refrigerant solution through the piping to freeze the soil porewater. Freeze plants are used to keep the containment structure at subfreezing temperatures. A full-scale containment structure was demonstrated from May 12 to October 10, 1994, at a nonhazardous site on SEG property on Gallaher Road, Oak Ridge, Tennessee

  15. Sustainable Hydraulic Barrier Design Technologies for Effective Infrastructure Engineering

    Directory of Open Access Journals (Sweden)

    Chitral Wijeyesekera Devapriya

    2017-01-01

    Full Text Available Migration of liquids lead to embarrassing post construction scenarios such as that of leaks from roofs, potable water leaking from water tanks/ reservoirs, rising damp in walls with groundwater seeping into basement structures, leakage of water from ornamental lakes and ponds or leachate leakage into the environment from MSW landfill sites. Such failures demand immediate and expensive maintenance. A stringent control on structural and waterproof stability is deemed necessary for long term service life of structures and in particular underground and near surface structures. On a micro scale and over a longer time scale, the phenomenon of rising dampness occurs in older buildings with the groundwater rising up through walls, floors and masonry via capillary action. Even slower rates of contaminant fluid migration occur through landfill base liners. In this paper a variety of hydraulic barrier technologies is critically discussed against a backdrop of relevant case studies. The choice of an appropriate hydraulic barrier technology for a given scenario will depend also on the sustainability, financial affordability and subjective aesthetics.

  16. Measurements of Effective Schottky Barrier in Inverse Extraordinary Optoconductance Structures

    Science.gov (United States)

    Tran, L. C.; Werner, F. M.; Solin, S. A.; Gilbertson, Adam; Cohen, L. F.

    2013-03-01

    Individually addressable optical sensors with dimensions as low as 250nm, fabricated from metal semiconductor hybrid structures (MSH) of AuTi-GaAs Schottky interfaces, display a transition from resistance decreasing with intensity in micron-scale sensors (Extraordinary Optoconductance, EOC) to resistance increasing with intensity in nano-scale sensors (Inverse Extraordinary Optoconductance I-EOC). I-EOC is attributed to a ballistic to diffusive crossover with the introduction of photo-induced carriers and gives rise to resistance changes of up to 9462% in 250nm devices. We characterize the photo-dependence of the effective Schottky barrier in EOC/I-EOC structures by the open circuit voltage and reverse bias resistance. Under illumination by a 5 mW, 632.8 nm HeNe laser, the barrier is negligible and the Ti-GaAs interface becomes Ohmic. Comparing the behavior of two devices, one with leads exposed, another with leads covered by an opaque epoxy, the variation in Voc with the position of the laser can be attributed to a photovoltaic effect of the lead metal and bulk GaAs. The resistance is unaffected by the photovoltaic offset of the leads, as indicated by the radial symmetry of 2-D resistance maps obtained by rastering a laser across EOC/IEOC devices. SAS has a financial interest in PixelEXX, a start-up company whose mission is to market imaging arrays.

  17. Barriers to cervical cancer screening uptake among rural women in ...

    African Journals Online (AJOL)

    [5] Among Asian-American women, psychosocial ... poorly-trained personnel were health system-related barriers. In sub-Saharan ... explored the religious and cultural barriers to cervical screening ... perceived barriers to screening uptake.

  18. Engineered barrier construction in salt rock. Final report of project phase 2. Period covered: 1 July 1989 - 31 December 1992

    International Nuclear Information System (INIS)

    Stockmann, N.; Beinlich, A.; Droste, J.; Flach, D.; Glaess, F.; Jockwer, N.; Krogmann, P.; Miehe, R.; Moeller, J.; Schwaegermann, F.; Wallmueller, R.; Walter, F.; Yaramanci, U.

    1994-01-01

    The project report presents and explains data obtained by a specific measuring programme, giving evidence of the sealing efficiency of an engineered barrier comprising abutment, long-term barrier, and hydraulic short-term barrier, the sealing performance having been verified for shorter and longer periods of time ( up to approx. 500 years). Specific computer codes have been applied for computing and verifying the long-term efficiency of the complex engineered barrier system (artificial structures and surrounding rock). The technical feasibility and the performance of an engineered barrier for reliable sealing of a radwaste repository is thus demonstrated at a scale of 1:1 at the site of the Asse mine [de

  19. Performance of dynamic safety barriers-Structuring, modelling and visualization

    OpenAIRE

    Wikdahl, Olga

    2014-01-01

    The main objective of this master thesis is to discuss performance of dynamic safety barriers. A comprehensive literature review is performed in order to get understanding what dynamic safety barrier is. Three different concepts of dynamic safety barriers based on various meanings of dynamic were derived from the literature review: - dynamic safety barriers related to motion or physical force - dynamic safety barriers as updated barriers from dynamic risk analysis - dynamic safety ...

  20. Market and Policy Barriers to Energy Storage Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, Dhruv [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Currier, Aileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez, Jacquelynne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ma, Ookie [Dept. of Energy (DOE), Washington DC (United States) Office of Energy Efficiency and Renewable Energy; Kirby, Brendan [Consultant

    2013-09-01

    Electric energy storage technologies can provide numerous grid services; there are a number of factors that restrict their current deployment. The most significant barrier to deployment is high capital costs, though several recent deployments indicate that capital costs are decreasing and energy storage may be the preferred economic alternative in certain situations. However, a number of other market and regulatory barriers persist, limiting further deployment. These barriers can be categorized into regulatory barriers, market (economic) barriers, utility and developer business model barriers, cross-cutting barriers and technology barriers.

  1. Use of element model to evaluate transmissibility reduction due to barriers

    Energy Technology Data Exchange (ETDEWEB)

    Svanes, T.; South, D.; Dronen, O.M. [Statoil, Bergen (Norway)

    1997-08-01

    Water breakthrough has been observed a year earlier than expected in the productive Oseberg Formation in the Veslefrikk Field. Production data revealed extensive water override, whereas the opposite situation was expected based on a homogeneous and coarse flow simulation model. A new model was developed to include geological heterogeneities using a simple upscaling method. The Oseberg Fm. consists of an upper homogeneous unit (zone 2) and a lower unit containing thin barriers of shale and calcite cemented sandstone (zone 1). The barrier content varies laterally. When barriers are distributed in a complex 3D pattern, they reduce the upscaled horizontal transmissibility more than what is obtained by multiplying the sand permeability by the net-to-gross ratio (N/G). However, the transmissibility reduction strongly depends on the spatial distribution of barriers and their geometry. Therefore, a fine scale element model was used to derive the average transmissibility reduction as a function of N/G for alternative geological descriptions of the barriers. A geo-statistical method called General Marked Point Process was used to generate the fine scale descriptions. This work has resulted in a simple upscaling routine for horizontal transmissibility, which represents an effective bridge between geological evaluation of uncertainties and fluid flow simulation. The method combines geo-statistical and deterministic modelling in an elegant manner, recognising that most often these methods complement one another.

  2. Low-impact, high toughness transportation barriers.

    Science.gov (United States)

    2012-10-01

    Alternatives to existing transportation truck escape ramps and crash barriers are examined using arrays of : wood, bamboo, and fiberglass structural elements that act as energy absorbers as they deform. The : behaviors of each material type are analy...

  3. Addressing the Barriers to Young Women's Economic ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    -understand how women overcome barriers to economic empowerment ... the United Kingdom's Department for International Development, The William and Flora ... Call for new OWSD Fellowships for Early Career Women Scientists now open.

  4. Nuclear reorganization barriers to electron transfer

    International Nuclear Information System (INIS)

    Sutin, N.; Brunschwig, B.S.; Creutz, C.; Winkler, J.R.

    1988-01-01

    The nuclear barrier to electron transfer arises from the need for reorganization of intramolecular and solvent internuclear distances prior to electron transfer. For reactions with relatively small driving force (''normal'' free-energy region) the nuclear factors and rates increase as intrinsic inner-shell and outer-shell barriers decrease; this is illustrated by data for transition metal complexes in their ground electronic states. By contrast, in the inverted free-energy region, rates and nuclear factors decrease with decreasing ''intrinsic'' barriers; this is illustrated by data for the decay of charge-transfer excited states. Several approaches to the evaluation of the outer-shell barrier are explored in an investigation of the distance dependence of the nuclear factor in intramolecular electron-transfer processes. 39 refs., 14 figs., 3 tabs

  5. Barrier Cavities in the Brookhaven AGS

    International Nuclear Information System (INIS)

    Blaskiewicz, M.; Brennan, J. M.; Roser, T.; Smith, K.; Spitz, R.; Zaltsman, A.; Fujieda, M.; Iwashita, Y.; Noda, A.; Yoshii, M.; Mori, Y.; Ohmori, C.; Sato, Y.

    1999-01-01

    In collaboration with KEK two barrier cavities, each generating 40 kV per turn have been installed in the Brookhaven AGS. Machine studies are described and their implications for high intensity operations are discussed

  6. Break down these barriers to medication safety.

    Science.gov (United States)

    2009-06-01

    Survey says of 2,200 ED nurses from 131 EDs, barriers to complying with medication-related NPSGs are common. Consider additional education of employees. One hospital uses computerized charting system to quicken triage process.

  7. DOE UST interim subsurface barrier technologies workshop

    International Nuclear Information System (INIS)

    1992-09-01

    This document contains information which was presented at a workshop regarding interim subsurface barrier technologies that could be used for underground storage tanks, particularly the tank 241-C-106 at the Hanford Reservation

  8. Cost and effectiveness of radon barrier systems

    International Nuclear Information System (INIS)

    Baker, E.G.; Freeman, H.D.; Hartley, J.N.; Gee, G.W.

    1982-12-01

    Earthen, asphalt, and multilayer radon barrier systems can all provide reduction in the amount of radon gas released from uranium mill tailings. Pacific Northwest Laboratory field tested all three types of covers at Grand Junction, Colorado during the summer of 1981. All nine individual radon barrier systems tested currently meet the EPA standard for radon flux of 20 pCi m - 2 s - 1 . The cost of the asphalt and 3m earthen covers were about the same at the field test. Multilayer covers were significantly more costly. Cost estimates for three high priority western sites indicate 3m of earthen cover is the least costly radon barrier when earthen material is available at or near the disposal site. If earthen material must be imported more than 8 to 10 km asphalt and possibly multilayer radon barriers can be cost effective

  9. Markers for blood-brain barrier integrity

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld

    2015-01-01

    In recent years there has been a resurgence of interest in brain barriers and various roles their intrinsic mechanisms may play in neurological disorders. Such studies require suitable models and markers to demonstrate integrity and functional changes at the interfaces between blood, brain......, and cerebrospinal fluid. Studies of brain barrier mechanisms and measurements of plasma volume using dyes have a long-standing history, dating back to the late nineteenth-century. Their use in blood-brain barrier studies continues in spite of their known serious limitations in in vivo applications. These were well...... known when first introduced, but seem to have been forgotten since. Understanding these limitations is important because Evans blue is still the most commonly used marker of brain barrier integrity and those using it seem oblivious to problems arising from its in vivo application. The introduction...

  10. Fusion barrier distributions - What have we learned?

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    1998-01-01

    The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

  11. Barriers to learning from incidents and accidents

    NARCIS (Netherlands)

    Dechy, N.; Dien, Y.; Drupsteen, L.; Felicio, A.; Cunha, C.; Roed-Larsen, S.; Marsden, E.; Tulonen, T.; Stoop, J.; Strucic, M.; Vetere Arellano, A.L.; Vorm, J.K.J. van der; Benner, L.

    2015-01-01

    This document provides an overview of knowledge concerning barriers to learning from incidents and accidents. It focuses on learning from accident investigations, public inquiries and operational experience feedback, in industrial sectors that are exposed to major accident hazards. The document

  12. Barriers to Physical Activity on University Student

    Science.gov (United States)

    Jajat; Sultoni, K.; Suherman, A.

    2017-03-01

    The purpose of the research is to analyze the factors that become barriers to physical activity in university students based on physical activity level. An internet-based survey was conducted. The participants were 158 University students from Universitas Pendidikan Indonesia. Barriers to Physical Activity Quiz (BPAQ) were used to assessed the factors that become barriers to physical activity in university students. IPAQ (short form) were used to assessed physical activity level. The results show there was no differences BPAQ based on IPAQ level. But when analyzed further based on seven factors barriers there are differences in factors “social influence and lack of willpower” based IPAQ level. Based on this it was concluded that the “influence from other and lack of willpower” an inhibiting factor on students to perform physical activity.

  13. Nuclear structure and fusion at the barrier

    International Nuclear Information System (INIS)

    Reisdorf, W.

    1985-01-01

    A comparative study of measured fusion excitation functions in the vicinity of the barrier reveals nuclear structure effects, due in particular to the coupling of the fusion process to direct-reaction channels. (orig.)

  14. Communicating across barriers at home and abroad

    Science.gov (United States)

    McDonald, J. W.

    This paper intends to catalyze the exchange of experience among technical communicators in meeting the challenge of communicating across a multitude of barriers: linguistic, disciplinary, cultural, political, intellectual, and emotional.

  15. JET internal transport barriers: experiment vs theory

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, B [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Crisanti, F [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Parail, V [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Maget, P [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Baranov, Y [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Becoulet, A [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Castaldo, C [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Challis, C D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Angelis, R De [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Garbet, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Giroud, C [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Hawkes, N [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Joffrin, E [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Litaudon, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Mazon, D [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Riva, M [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Zastrow, K D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2003-06-01

    A large variety of JET discharges with internal transport barriers (ITBs) has been analysed in order to determine the main features which characterize turbulence stabilization at the barrier. It is found that the location of barriers is well correlated with regions where the ExB flow shearing rate exceeds the linear growth rate of the ion temperature gradient mode instability ({gamma}{sub {eta}{sub i}}). A key point is the dependence of {gamma}{sub {eta}{sub i}} on the magnetic shear: in the discharges of this database the reduction of {gamma}{sub {eta}{sub i}} associated to very low or null magnetic shear favours the formation of an ITB. After the ITB formation a positive feedback occurs in which the ExB flow shear mechanism has the leading role and the position of the barrier may be no longer linked to the low shear region.

  16. Overcoming Barriers to Shared Decision Making

    Science.gov (United States)

    ... a social worker can help. Barrier: Language differences Solution: More than 13 million people in the U.S. age 5 and older speak little or no English, according to the U.S. Census Bureau. Some hospitals ...

  17. Evapotranspiration studies for protective barriers: Experimental plans

    International Nuclear Information System (INIS)

    Link, S.O.; Waugh, W.J.

    1989-11-01

    This document describes a general theory and experimental plans for predicting evapotranspiration in support of the Protective Barrier Program. Evapotranspiration is the combined loss of water from plants and soil surfaces to the atmosphere. 45 refs., 1 fig., 4 tabs

  18. Advanced house air-barrier systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.K. [Natural Resources Canada, Ottawa, ON (Canada)

    1996-08-01

    Air barrier systems used in modern Canadian airtight homes were discussed. The Advanced Houses Program sets its airtightness requirements at 1.5 air changes per hour at 50 Pascals pressure difference (ACH{sub 5}0). In recent tests of 10 houses, it was suggested that a better airtightness level was attainable with average airtightness of about 1.0 ACH{sub 5}0. Six of the homes tested did not use the traditional polyethylene approach. Two of the houses used the airtight drywall approach, one used a foam system, and three used exterior air barriers. The advantages and disadvantages of each system was described, including cost effectiveness, cost reduction, performance and installation advantages. The confusion between an air barrier and a vapour diffusion retarder was explained. Exterior air barriers showed the greatest potential for meeting airtightness requirements at reasonable cost. 5 refs., 3 tabs.

  19. Electron tunneling across a tunable potential barrier

    International Nuclear Information System (INIS)

    Mangin, A; Anthore, A; Rocca, M L Della; Boulat, E; Lafarge, P

    2009-01-01

    We present an experiment where the elementary quantum electron tunneling process should be affected by an independent gate voltage parameter. We have realized nanotransistors where the source and drain electrodes are created by electromigration inducing a nanometer sized gap acting as a tunnel barrier. The barrier potential shape is in first approximation considered trapezoidal. The application of a voltage to the gate electrode close to the barrier region can in principle affect the barrier shape. Simulations of the source drain tunnel current as a function of the gate voltage predict modulations as large as one hundred percent. The difficulty of observing the predicted behaviour in our samples might be due to the peculiar geometry of the realized tunnel junction.

  20. Stochastic transport of particles across single barriers

    International Nuclear Information System (INIS)

    Kreuter, Christian; Siems, Ullrich; Henseler, Peter; Nielaba, Peter; Leiderer, Paul; Erbe, Artur

    2012-01-01

    Transport phenomena of interacting particles are of high interest for many applications in biology and mesoscopic systems. Here we present measurements on colloidal particles, which are confined in narrow channels on a substrate and interact with a barrier, which impedes the motion along the channel. The substrate of the particle is tilted in order for the particles to be driven towards the barrier and, if the energy gained by the tilt is large enough, surpass the barrier by thermal activation. We therefore study the influence of this barrier as well as the influence of particle interaction on the particle transport through such systems. All experiments are supported with Brownian dynamics simulations in order to complement the experiments with tests of a large range of parameter space which cannot be accessed in experiments.

  1. Proxy records of Holocene storm events in coastal barrier systems: Storm-wave induced markers

    Science.gov (United States)

    Goslin, Jérôme; Clemmensen, Lars B.

    2017-10-01

    Extreme storm events in the coastal zone are one of the main forcing agents of short-term coastal system behavior. As such, storms represent a major threat to human activities concentrated along the coasts worldwide. In order to better understand the frequency of extreme events like storms, climate science must rely on longer-time records than the century-scale records of instrumental weather data. Proxy records of storm-wave or storm-wind induced activity in coastal barrier systems deposits have been widely used worldwide in recent years to document past storm events during the last millennia. This review provides a detailed state-of-the-art compilation of the proxies available from coastal barrier systems to reconstruct Holocene storm chronologies (paleotempestology). The present paper aims (I) to describe the erosional and depositional processes caused by storm-wave action in barrier and back-barrier systems (i.e. beach ridges, storm scarps and washover deposits), (ii) to understand how storm records can be extracted from barrier and back-barrier sedimentary bodies using stratigraphical, sedimentological, micro-paleontological and geochemical proxies and (iii) to show how to obtain chronological control on past storm events recorded in the sedimentary successions. The challenges that paleotempestology studies still face in the reconstruction of representative and reliable storm-chronologies using these various proxies are discussed, and future research prospects are outlined.

  2. Development of a design package for a viscous barrier at the Savannah River Site

    International Nuclear Information System (INIS)

    Moridis, G.J.; James, A.; Oldenburg, C.

    1996-10-01

    This paper describes elements of a design for a pilot-scale field demonstration of a new subsurface containment technology for waste isolation developed at the Lawrence Berkeley National Laboratory (LBNL), which uses a new generation of barrier liquids for permeation grouting. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site (SRS), originally built to control contaminated runoff for the H Reactor, and which has been contaminated mainly by radionuclides. The LBNL viscous barrier technology employs barrier liquids which, when injected into the subsurface, produce chemically benign nearly impermeable barriers through a very large increase in viscosity. The initially low-viscosity liquids are emplaced through multiple injection points in the subsurface and the intersecting plumes merge and completely surround the contaminant source and/or plume. Once in place, they gel or cure to form a nearly impermeable barrier. The barrier liquid to be used in this application is Colloidal Silica (CS), an aqueous suspension of silica microspheres in a stabilizing electrolyte. It has excellent durability characteristics, poses no health hazard, is practically unaffected by filtration, and is chemically and biologically benign

  3. 200-BP-1 Prototype Hanford Barrier -- 15 Years of Performance Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Anderson L.; Draper, Kathryn E.; Link, Steven O.; Clayton, Ray E.

    2011-09-30

    Monitoring is an essential component of engineered barrier system design and operation. A composite capacitive cover, including a capillary break and an evapotranspiration (ET) barrier at the Hanford Site, is generating data that can be used to help resolve these issues. The prototype Hanford barrier was constructed over the 216-B-57 Crib in 1994 to evaluate surface-barrier constructability, construction costs, and physical and hydrologic performance at the field scale. The barrier has been routinely monitored between November 1994 and September 1998 as part of a Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) treatability test of barrier performance for the 200 BP 1 Operable Unit. Since FY 1998, monitoring has focused on a more limited set of key water balance, stability, and biotic parameters. In FY 2009, data collection was focused on: (1) water-balance monitoring, consisting of precipitation, runoff, soil moisture storage, and drainage measurements with evapotranspiration calculated by difference; (2) stability monitoring, consisting of asphalt-layer-settlement, basalt-side-slope-stability, and surface-elevation measurements; (3) vegetation dynamics; and (4) animal use. September 2009 marked 15 years since the start of monitoring and the collection of performance data. This report describes the results of monitoring activities during the period October 1, 2008, through September 30, 2009, and summarizes the 15 years of performance data collected from September 1994 through September 2009.

  4. Super Oxygen and Improved Water Vapor Barrier of Polypropylene Film with Polyelectrolyte Multilayer Nanocoatings.

    Science.gov (United States)

    Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C

    2016-06-01

    Biaxially oriented polypropylene (BOPP) is widely used in packaging. Although its orientation increases mechanical strength and clarity, BOPP suffers from a high oxygen transmission rate (OTR). Multilayer thin films are deposited from water using layer-by-layer (LbL) assembly. Polyethylenimine (PEI) is combined with either poly(acrylic acid) (PAA) or vermiculite (VMT) clay to impart high oxygen barrier. A 30-bilayer PEI/VMT nanocoating (226 nm thick) improves the OTR of 17.8 μm thick BOPP by more than 30X, rivaling most inorganic coatings. PEI/PAA multilayers achieve comparable barrier with only 12 bilayers due to greater thickness, but these films exhibit increased oxygen permeability at high humidity. The PEI/VMT coatings actually exhibit improved oxygen barrier at high humidity (and also improve moisture barrier by more than 40%). This high barrier BOPP meets the criteria for sensitive food and some electronics packaging applications. Additionally, this water-based coating technology is cost effective and provides an opportunity to produce high barrier polypropylene film on an industrial scale. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Energy efficiency barriers in commercial and industrial firms in Ukraine: An empirical analysis

    International Nuclear Information System (INIS)

    Hochman, Gal; Timilsina, Govinda R.

    2017-01-01

    Improvement in energy efficiency is one of the main options to reduce energy demand and greenhouse gas emissions. However, large-scale deployment of energy-efficient technologies is constrained by several factors. Employing a survey of 509 industrial and commercial firms throughout Ukraine and a generalized ordered logit model, we quantified the economic, behavioral, and institutional barriers that may impede the deployment of energy-efficient technologies. Our analysis shows that behavioral barriers resulted from lack of information, knowledge, and awareness are major impediments to the adoption of energy-efficient technologies in Ukraine, and that financial barriers may further impede investments in these technologies especially for small firms. This suggests that carefully targeted information provisions and energy audits will enhance Ukrainian firms' investments in energy-efficient technologies to save energy consumption, improve productivity, and reduce carbon emissions from the productive sectors. - Highlights: • Employing a survey of 509 industrial and commercial firms throughout Ukraine • A generalized ordered logit model is used in the analysis. • The paper quantifies the economic, behavioral, and institutional barriers to energy-efficient technologies. • Behavioral barriers are major impediments to the adoption of energy-efficient technologies. • Financial barriers may further impede investments in these technologies especially for small firms.

  6. Jordanian dialysis patients' perceived exercise benefits and barriers: a correlation study.

    Science.gov (United States)

    Darawad, Muhammad W; Khalil, Amani A

    2013-01-01

    To investigate Jordanian end-stage renal disease (ESRD)patients' perceived exercise benefits and barriers, and their correlation with patients' demographic variables and dialysis measures. A descriptive correlational study was conducted using cross-sectional survey, using a convenience sample of 190 ESRD dialyzed patients who were recruited from eight hospitals in Jordan. Participants significantly perceived exercise benefits (M= 2.88/4, SD± .67) higher than barriers (M= 2.66, SD± .62). The most frequent perceived exercise benefits were preventing muscular atrophy and improving mood, whereas tiredness and lower-extremity fatigue were the most frequent exercise barriers. Finally, acceptable values of Cronbach's Alpha were revealed for perceived exercise subscale, barriers subscale, and total scale (α= .88, .81, and .70, respectively). Participants focused more on exercise benefits than barriers, and on direct exercise benefits and barriers than the indirect. The results of this study have important implications for the efforts that aim at improving ESRD patients' exercise behaviors. © 2013 Association of Rehabilitation Nurses.

  7. Frozen soil barriers for hazardous waste confinement

    International Nuclear Information System (INIS)

    Dash, J.G.; Leger, R.; Fu, H.Y.

    1997-01-01

    Laboratory and full field measurements have demonstrated the effectiveness of artificial ground freezing for the containment of subsurface hazardous and radioactive wastes. Bench tests and a field demonstration have shown that cryogenic barriers are impenetrable to aqueous and non aqueous liquids. As a result of the successful tests the US Department of Energy has designated frozen ground barriers as one of its top ten remediation technologies

  8. Phonic Attenuation due to Screen-Barriers

    Directory of Open Access Journals (Sweden)

    Vasile Bacria

    2011-10-01

    Full Text Available The technique of noise decreasing admits two basic approaches: an active approach and a passive one. In the frame of passive method one can count the employment of screen-barriers. In this paper we present some considerations on sound attenuation due to screen-barriers emphasizing the elements which influence it. The elucidation of these elements is made by measurements. The obtained results can be applied in every other practical situation concerning the protection against noise.

  9. Immigrant language barriers and house prices

    OpenAIRE

    Fischer, Andreas M.

    2011-01-01

    Are language skills important in explaining the nexus between house prices and immigrant inflows? The language barrier hypothesis says immigrants from a non common language country value amenities more than immigrants from common language countries.> ; In turn, immigrants from non common language countries are less price sensitive to house price changes than immigrants from a common language country. Tests of the language barrier hypothesis with Swiss house prices show that an immigration inf...

  10. Using Frozen Barriers for Containment of Contaminants

    Science.gov (United States)

    2017-09-21

    barriers are constructed of grout slurry and plastic or steel sheet pilings. Circumferential barriers can be used to completely enclose a source of...2.1.1 Slurry walls A soil-bentonite slurry trench cutoff wall (slurry wall) is excavated and backfilled with grout, cement , or soil-bentonite...installation requires a mixing area, and there is a substantial amount of excavation and the need to dispose of spoil. The advantages of cement -based

  11. Structural Stability of Tokamak Equilibrium: Transport Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Solano, E. R.

    2001-07-01

    A generalised theory of structural stability of differential equations is introduced and applied to the Grad-Shafranov equation. It is discussed how the formation and loss of transport barrier could be associated with the appearance/disappearance of equilibria. The equilibrium conjecture is presented: transport barriers are associated with locally diamagnetic regions in the plasma, and affected by the paramagnetism of the bootstrap current. (Author) 18 refs.

  12. Breaching barriers to collaboration in public spaces

    DEFF Research Database (Denmark)

    Heinemann, Trine; Mitchell, Robb

    2014-01-01

    Technology provoking disparate individuals to collaborate or share experiences in the public space faces a difficult barrier, namely the ordinary social order of urban places. We employed the notion of the breaching experiment to explore how this barrier might be overcome. We analyse responses...... of life in public spaces. Arising from this, we argue for the importance of qualities such as availability, facilitation, perspicuous settings, and perspicuous participants to encourage and support co-located strangers to collaborate and share experiences....

  13. ENA study cites barriers to NPSG compliance.

    Science.gov (United States)

    2009-04-01

    There are many barriers to compliance with the National Patient Safety Goals, as a recent study shows. However, emergency medicine experts say there are several strategies you can adopt to help overcome those barriers. Send the right message to your staff by establishing a culture of shared responsibility for safety. Establish scripts for talking with patients. Standardization will help ensure they are getting the correct information. Put standardized abbreviations on posters in your department, and list them on your medication reconciliation form.

  14. Nuclear energy technology transfer: the security barriers

    International Nuclear Information System (INIS)

    Rinne, R.L.

    1975-08-01

    The problems presented by security considerations to the transfer of nuclear energy technology are examined. In the case of fusion, the national security barrier associated with the laser and E-beam approaches is discussed; for fission, the international security requirements, due to the possibility of the theft or diversion of special nuclear materials or sabotage of nuclear facilities, are highlighted. The paper outlines the nuclear fuel cycle and terrorist threat, examples of security barriers, and the current approaches to transferring technology. (auth)

  15. Barriers in EU retail financial markets

    OpenAIRE

    Micuda, Dan

    2007-01-01

    Looking at the retail financial markets and identifing a number of ‘‘natural’’ and ‘‘policy induced’’ obstacles to free trade. We use the term ‘‘natural’’ barriers to refer to those arising as a result of different cultures or consumer preferences, while different state tax policies or regulations are classified as ‘‘policy induced’’ barriers.

  16. Music therapists' research activity and utilization barriers: a survey of the membership.

    Science.gov (United States)

    Waldon, Eric G

    2015-01-01

    Music therapists have access to a rapidly expanding body of research supporting the use of music-based interventions. What is not known is the extent to which music therapists access these resources and what factors may prevent them from incorporating research findings into clinical work. After constructing the Music Therapists' Research Activity and Utilization Barrier (MTRAUB) database, the purposes of this study involved: assessing the extent to which American Music Therapy Association (AMTA) members engage in certain research-related activities; and identifying respondents' perceived barriers to integrating research into clinical practice. This study employed a quantitative, non-experimental approach using an online survey. Respondents included professional, associate, student/graduate student, retired, inactive, and honorary life members of AMTA. Instrumentation involved a researcher-designed Background Questionnaire as well as the Barriers to Research Utilization Scale (BARRIERS; Funk, Champagne, Wiese, & Tornquist, 1991), a tool designed to assess perceived barriers to incorporating research into practice. Of the 3,194 survey invitations distributed, 974 AMTA members replied (a response rate of 30%). Regarding research-related activities, descriptive findings indicate that journal reading is the most frequently reported research-related activity while conducting research is the least frequently reported activity. Results from the BARRIERS Scale indicated that Organizational and Communication factors are perceived as interfering most prominently with the ability to utilize research in clinical practice. Findings suggest that research-related activity and perceived barriers vary as a function of educational attainment, work setting, and occupational role. The author discusses these differential findings in detail, suggests supportive mechanisms to encourage increased research activity and utilization, and offers recommendations for further analysis of the

  17. Structuring unbreakable hydrophobic barriers in paper

    Science.gov (United States)

    Nargang, Tobias M.; Kotz, Frederik; Rapp, Bastian E.

    2018-02-01

    Hydrophobic barriers are one of the key elements of microfluidic paper based analytical devices (μPADs).μPADs are simple and cost efficient and they can be carried out without the need of high standard laboratories. To carry out such a test a method is needed to create stable hydrophobic barriers. Commonly used methods like printing wax or polystyrene have the major drawback that these barriers are stiff and break if bended which means they will no longer be able to retain a liquid sample. Here we present silanes to structure hydrophobic barriers via polycondensation and show a silanization method which combines the advantages of flexible silane/siloxane layers with the short processing times of UV-light based structuring. The barriers are created by using methoxy silanes which are mixed with a photo acid generator (PAG) as photoinitiator. Also a photosensitizer was given to the mixture to increase the effectiveness of the PAG. After the PAG is activated by UV-light the silane is hydrolyzed and coupled to the cellulose via polycondensation. The created hydrophobic barriers are highly stable and do not break if being bended.

  18. Treatment of barrier evolution: the SKB perspective

    International Nuclear Information System (INIS)

    Hedin, A.

    2002-01-01

    This paper serves as a point of departure for the discussions to be held within the Working Group of Technical Topic entitled 'Barriers and System Performances within a safety case: Their functioning and Evolution with Time'. The paper gives the SKB perspective of the issues to be discussed within the Working Group for this Topic. The following issues to be discussed by the Working Group are: What is the role of each barrier as a function of time or in the different time frames? What is its contribution to the overall system performance or safety as a function of time? Which are the main uncertainties on the performance of barriers in the timescales? To what extent should we enhance the robustness of barriers because of the uncertainties of some component behaviour with time? What is the requested or required performance versus the expected or realistic or conservative behaviour with time? How are these safety margins used as arguments in a safety case? What is the issue associated with the geosphere stability for different geological systems? How is barriers and system performances as a function of time evaluated (and presented and communicated) in a safety case? What kind of measures are used for siting, designing and optimising robust barriers corresponding to situations that can vary with time? Are human actions considered to be relevant? (authors)

  19. Scaling studies of the H-mode pedestal

    International Nuclear Information System (INIS)

    Groebner, R.J.; Osborne, T.H.

    1998-01-01

    The structure and scaling of the H-mode pedestal are examined for discharges in the DIII-D tokamak. For typical conditions, the pedestal values of the ion and electron temperatures T i and T e are comparable. Measurements of main ion and C 6+ profiles indicate that the ion pressure gradient in the barrier is 50%--100% of the electron pressure gradient for deuterium plasmas. The magnitude of the pressure gradient in the barrier often exceeds the predictions of infinite-n ballooning mode theory by a factor of two. Moreover, via the bootstrap current, the finite pressure gradient acts to entirely remove ballooning stability limits for typical discharges. For a large dataset, the width of the pressure barrier δ is best described by the dimensionless scaling δ/R ∝ (β pol ped ) 0.4 where (β pol ped ) is the pedestal value of poloidal beta and R is the major radius. Scalings based on the poloidal ion gyroradius or the edge density gradient do not adequately describe overall trends in the data set and the propagation of the pressure barrier observed between edge-localized modes. The width of the T i barrier is quite variable and is not a good measure of the width of the pressure barrier

  20. The Physics of Internal Transport Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Tala, T.; Andrew, Y.; Crombe, K.; Garbet, X.; Hawkes, N.; Kierneva, N.; Mantica, P.; Piches, S.; Thyagaraja, A.; Weiland, J.

    2007-07-01

    The Internal Transport Barriers (ITBs) were found more than a decade ago. Still for the time being, there are many open questions concerning their physics and dynamics. Several mechanisms are believed to affect the triggering and formation of the ITB, and subsequent dynamical processes, like expansion, strengthening and collapse of the barrier. Regarding the question of dominant ITB formation mechanisms, many experimental results on JET are consistent with ITB dynamics controlled by the E X B flow shear and local magnetic shear. On the other hand, the actual triggering of the ITB is less clear. While the role of minimum value of the q profile approaching an integer value is known to be significant, the actual role of q is delicate as the ITB is triggered before q min reaches an integer value, indicated by the grand Alfven Cascades. The prime candidate to explain the ITB triggering is the E X B flow shear. The increase in the EXB flow shear within the ITB is experimentally seen as a spin-up of the carbon poloidal velocity with the charge exchange resonance spectroscopy measurements. Furthermore, the transport modelling with the Weiland and GLF23 transport models using the experimental poloidal velocity instead of the neoclassical one strongly supports the crucial role of EXB flow shear in triggering the ITB. The causality between the onset of the ITB and spin-up of the poloidal velocity has been studied extensively and will be reported here. The role of magnetic shear is also undisputable. When the magnetic shear is negative enough, for example in the case of current hole, a strong ITB in the electron channel is observed, and often with very small EXB flow shear. The role of magnetic shear is less clear for ion heat transport channel. Certainly it facilitates the ITB formation, but whether it alone is able to trigger an ITB has not been proven. The role of stabilisation, the role of density peaking, the dilution effects due to impurities and fast particles are

  1. How thin barrier metal can be used to prevent Co diffusion in the modern integrated circuits?

    International Nuclear Information System (INIS)

    Dixit, Hemant; Konar, Aniruddha; Pandey, Rajan; Ethirajan, Tamilmani

    2017-01-01

    In modern integrated circuits (ICs), billions of transistors are connected to each other via thin metal layers (e.g. copper, cobalt, etc) known as interconnects. At elevated process temperatures, inter-diffusion of atomic species can occur among these metal layers, causing sub-optimal performance of interconnects, which may lead to the failure of an IC. Thus, typically a thin barrier metal layer is used to prevent the inter-diffusion of atomic species within interconnects. For ICs with sub-10 nm transistors (10 nm technology node), the design rule (thickness scaling) demands the thinnest possible barrier layer. Therefore, here we investigate the critical thickness of a titanium–nitride (TiN) barrier that can prevent the cobalt diffusion using multi-scale modeling and simulations. First, we compute the Co diffusion barrier in crystalline and amorphous TiN with the nudged elastic band method within first-principles density functional theory simulations. Later, using the calculated activation energy barriers, we quantify the Co diffusion length in the TiN metal layer with the help of kinetic Monte Carlo simulations. Such a multi-scale modelling approach yields an exact critical thickness of the metal layer sufficient to prevent the Co diffusion in IC interconnects. We obtain a diffusion length of a maximum of 2 nm for a typical process of thermal annealing at 400 °C for 30 min. Our study thus provides useful physical insights for the Co diffusion in the TiN layer and further quantifies the critical thickness (∼2 nm) to which the metal barrier layer can be thinned down for sub-10 nm ICs. (paper)

  2. How thin barrier metal can be used to prevent Co diffusion in the modern integrated circuits?

    Science.gov (United States)

    Dixit, Hemant; Konar, Aniruddha; Pandey, Rajan; Ethirajan, Tamilmani

    2017-11-01

    In modern integrated circuits (ICs), billions of transistors are connected to each other via thin metal layers (e.g. copper, cobalt, etc) known as interconnects. At elevated process temperatures, inter-diffusion of atomic species can occur among these metal layers, causing sub-optimal performance of interconnects, which may lead to the failure of an IC. Thus, typically a thin barrier metal layer is used to prevent the inter-diffusion of atomic species within interconnects. For ICs with sub-10 nm transistors (10 nm technology node), the design rule (thickness scaling) demands the thinnest possible barrier layer. Therefore, here we investigate the critical thickness of a titanium-nitride (TiN) barrier that can prevent the cobalt diffusion using multi-scale modeling and simulations. First, we compute the Co diffusion barrier in crystalline and amorphous TiN with the nudged elastic band method within first-principles density functional theory simulations. Later, using the calculated activation energy barriers, we quantify the Co diffusion length in the TiN metal layer with the help of kinetic Monte Carlo simulations. Such a multi-scale modelling approach yields an exact critical thickness of the metal layer sufficient to prevent the Co diffusion in IC interconnects. We obtain a diffusion length of a maximum of 2 nm for a typical process of thermal annealing at 400 °C for 30 min. Our study thus provides useful physical insights for the Co diffusion in the TiN layer and further quantifies the critical thickness (~2 nm) to which the metal barrier layer can be thinned down for sub-10 nm ICs.

  3. Adapting to climate change by water management organisations: Enablers and barriers

    Science.gov (United States)

    Azhoni, Adani; Jude, Simon; Holman, Ian

    2018-04-01

    Climate change will be particularly experienced though the medium of water. Water organisations, that are managing societal and ecological needs for water, are therefore likely to experience the impact the most. This study reviews the current literature regarding adaptation to climate change by water management organisations and associated barriers. Literature on adaptive capacity is growing and a general consensus is emerging on the determinants of adaptive capacity, although variations exist regarding how it is to be evaluated, enhanced and applied to policy making due to its dynamic, contextual and latent nature. Since adaptive capacity is hard to measure and successful adaptation difficult to define, some studies focus on the existence of adaptation attributes of organisations. Studies reporting successful adaptation are minimal and barriers of adaptation are being discovered as adaptation research transitions into implementation. But the root causes of these barriers are often overlooked and the interconnectedness of the barriers is poorly addressed. Increasingly, combining top-down and bottom-up approaches to adaptation is being recommended due to the limitations of each. However, knowledge regarding how organisations operating at different scales can enhance adaptive capacity of other organisations operating at another scale is lacking due to the few studies of inter-organisational networks across scales. Social networks among actors are recognised as a key factor to enable adaptation. However, network studies generally focus on individual actors and rarely between public agencies/organisations. Moreover, the current literature is inadequate to understand the relationship between adaptation enabling characteristics, barriers and adaptation manifestation. The review demonstrates that research on understanding the emergence and sustenance of barriers is urgently required. Addressing these knowledge gaps will help to improve the design of adaptation strategies

  4. Perceived exercise benefits and barriers of non-exercising female university students in the United Kingdom.

    Science.gov (United States)

    Lovell, Geoff P; El Ansari, Walid; Parker, John K

    2010-03-01

    Many individuals do not engage in sufficient physical activity due to low perceived benefits and high perceived barriers to exercise. Given the increasing incidence of obesity and obesity related health disorders, this topic requires further exploration. We used the Exercise Benefits/Barriers Scale to assess perceived benefit and barrier intensities to exercise in 200 non-exercising female university students (mean age 19.3 years, SD = 1.06) in the UK. Although our participants were selected because they self reported themselves to be non-exercising, however they reported significantly higher perceived benefits from exercise than perceived barriers to exercise [t(199) = 6.18, p exercise was physical performance followed by the benefits of psychological outlook, preventive health, life enhancement, and then social interaction. Physical performance was rated significantly higher than all other benefits. Psychological outlook and preventive health were not rated significantly different, although both were significantly higher than life enhancement and social interaction. Life enhancement was also rated significantly higher than social interaction. The greatest perceived barrier to exercise was physical exertion, which was rated significantly higher than time expenditure, exercise milieu, and family discouragement barriers. Implications from this investigation for the design of physical activity programmes include the importance, for females, of a perception of high benefit/barrier ratio that could be conducive to participation in exercise. Applied interventions need to assist female students to 'disengage' from or overcome any perceived 'unpleasantness' of physical exertion during physical activity (decrease their perceived barriers), and to further highlight the multiple health and other benefits of regular exercising (increase their perceived benefits).

  5. Learning from social media: utilizing advanced data extraction techniques to understand barriers to breast cancer treatment.

    Science.gov (United States)

    Freedman, Rachel A; Viswanath, Kasisomayajula; Vaz-Luis, Ines; Keating, Nancy L

    2016-07-01

    Past examinations of breast cancer treatment barriers have typically included registry, claims-based, and smaller survey studies. We examined treatment barriers using a novel, comprehensive, social media analysis of online, candid discussions about breast cancer. Using an innovative toolset to search postings on social networks, message boards, patient communities, and topical sites, we performed a large-scale qualitative analysis. We examined the sentiments and barriers expressed about breast cancer treatments by Internet users during 1 year (2/1/14-1/31/15). We categorized posts based on thematic patterns and examined trends in discussions by race/ethnicity (white/black/Hispanic) when this information was available. We identified 1,024,041 unique posts related to breast cancer treatment. Overall, 57 % of posts expressed negative sentiments. Using machine learning software, we assigned treatment barriers for 387,238 posts (38 %). Barriers included emotional (23 % of posts), preferences and spiritual/religious beliefs (21 %), physical (18 %), resource (15 %), healthcare perceptions (9 %), treatment processes/duration (7 %), and relationships (7 %). Black and Hispanic (vs. white) users more frequently reported barriers related to healthcare perceptions, beliefs, and pre-diagnosis/diagnosis organizational challenges and fewer emotional barriers. Using a novel analysis of diverse social media users, we observed numerous breast cancer treatment barriers that differed by race/ethnicity. Social media is a powerful tool, allowing use of real-world data for qualitative research, capitalizing on the rich discussions occurring spontaneously online. Future research should focus on how to further employ and learn from this type of social intelligence research across all medical disciplines.

  6. Barriers to involvement in physical activities of persons with mental illness.

    Science.gov (United States)

    Shor, Ron; Shalev, Anat

    2016-03-01

    Participating in physical activities could be essential for reducing the multiple risk factors for health problems that persons with severe mental illness (SMI) may suffer. However, people with SMI are significantly less active than the general population. To develop knowledge about factors related to the perceived barriers hindering this population's participation in physical activities and the benefits this participation would have, a study was conducted in Israel with 86 people with mental illness living in community mental health facilities prior to their participation in a health promotion program. A mixed method was implemented and included: a scale designed to measure participants' perceptions of the barriers to and benefits of involvement in physical activities; instruments focusing on bio-psycho-social factors that may affect the level of barriers experienced; and personal interviews. The findings revealed high ranking for accessibility barriers hindering the participation in physical activities. Bio-psycho-social factors stemming from the participants' mental health, such as level of depression, were correlated with higher ranking of accessibility barriers. Bio-psycho-social factors reflecting positive mental health and health, such as positive appraisal of body weight, were correlated with lower ranking of accessibility barriers. Other barriers may include organizational and broader systemic barriers in the mental health facilities where the participants reside. These findings illuminate the need to consider the unique challenges that persons with mental illness may face in any attempt to advance their involvement in physical activity. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Assessing the appropriateness of carbon financing for micro-scale projects in terms of capabilities

    OpenAIRE

    Caitlin Trethewy

    2013-01-01

    Micro-scale development projects are currently underrepresented in global carbon markets. This paper outlines the process of becoming eligible to generate carbon credits and examines some of the barriers that may inhibit access to carbon markets. In particular, it focuses on barriers relating to the capacity and resources of the organisation developing the project. This approach represents a deviation from the standard discourse which has traditionally focused on barriers relating to the avai...

  8. Effect of the barrier properties on the surface part of the barrier discharge

    International Nuclear Information System (INIS)

    Sokolova, M.V.; Zhukov, S.V.

    1998-01-01

    The effect of barrier characteristics on the discharge processes in a barrier discharge was investigated, main attention being paid to the amount and distribution of the charge left on the barrier surface by the volume discharge in the main air gap. The measurements show that the main part of the gap charge is due to the volume part of the discharge. The measured values of the surface charge significantly increase with the voltage applied and with the length of the gas gap, while the dimensions of the charge spot and the distribution of charge density are determined by the barrier properties. (J.U.)

  9. Words that make pills easier to swallow: a communication typology to address practical and perceptual barriers to medication intake behavior

    Directory of Open Access Journals (Sweden)

    Linn AJ

    2012-12-01

    Full Text Available Annemiek J Linn,1 Julia CM van Weert,1 Barbara C Schouten,1 Edith G Smit,1 Ad A van Bodegraven,2 Liset van Dijk31Amsterdam School of Communication Research (ASCoR, University of Amsterdam, Amsterdam, The Netherlands; 2VU University Medical Center, Amsterdam, The Netherlands; 3Netherlands Institute for Health Services Research, Utrecht, The NetherlandsPurpose: The barriers to patients’ successful medication intake behavior could be reduced through tailored communication about these barriers. The aim of this study is therefore (1 to develop a new communication typology to address these barriers to successful medication intake behavior, and (2 to examine the relationship between the use of the typology and the reduction of the barriers to successful medication intake behavior.Patients and methods: Based on a literature review, the practical and perceptual barriers to successful medication intake behavior typology (PPB-typology was developed. The PPB-typology addresses four potential types of barriers that can be either practical (memory and daily routine barriers or perceptual (concern and necessity barriers. The typology describes tailored communication strategies that are organized according to barriers and communication strategies that are organized according to provider and patient roles. Eighty consultations concerning first-time medication use between nurses and inflammatory bowel disease patients were videotaped. The verbal content of the consultations was analyzed using a coding system based on the PPB-typology. The Medication Understanding and Use Self-efficacy Scale and the Beliefs about Medicine Questionnaire Scale were used as indicators of patients’ barriers and correlated with PPB-related scores.Results: The results showed that nurses generally did not communicate with patients according to the typology. However, when they did, fewer barriers to successful medication intake behavior were identified. A significant association was

  10. Words that make pills easier to swallow: a communication typology to address practical and perceptual barriers to medication intake behavior.

    Science.gov (United States)

    Linn, Annemiek J; van Weert, Julia Cm; Schouten, Barbara C; Smit, Edith G; van Bodegraven, Ad A; van Dijk, Liset

    2012-01-01

    The barriers to patients' successful medication intake behavior could be reduced through tailored communication about these barriers. The aim of this study is therefore (1) to develop a new communication typology to address these barriers to successful medication intake behavior, and (2) to examine the relationship between the use of the typology and the reduction of the barriers to successful medication intake behavior. Based on a literature review, the practical and perceptual barriers to successful medication intake behavior typology (PPB-typology) was developed. The PPB-typology addresses four potential types of barriers that can be either practical (memory and daily routine barriers) or perceptual (concern and necessity barriers). The typology describes tailored communication strategies that are organized according to barriers and communication strategies that are organized according to provider and patient roles. Eighty consultations concerning first-time medication use between nurses and inflammatory bowel disease patients were videotaped. The verbal content of the consultations was analyzed using a coding system based on the PPB-typology. The Medication Understanding and Use Self-efficacy Scale and the Beliefs about Medicine Questionnaire Scale were used as indicators of patients' barriers and correlated with PPB-related scores. The results showed that nurses generally did not communicate with patients according to the typology. However, when they did, fewer barriers to successful medication intake behavior were identified. A significant association was found between nurses who encouraged question-asking behavior and memory barriers (r = -0.228, P = 0.042) and between nurses who summarized information (r = -0.254, P = 0.023) or used cartoons or pictures (r = -0.249, P = 0.026) and concern barriers. Moreover, a significant relationship between patients' emotional cues about side effects and perceived concern barriers (r = 0.244, P = 0.029) was found as well

  11. Potential corridors and barriers for plague spread in central Asia

    Science.gov (United States)

    2013-01-01

    Background Plague (Yersinia pestis infection) is a vector-borne disease which caused millions of human deaths in the Middle Ages. The hosts of plague are mostly rodents, and the disease is spread by the fleas that feed on them. Currently, the disease still circulates amongst sylvatic rodent populations all over the world, including great gerbil (Rhombomys opimus) populations in Central Asia. Great gerbils are social desert rodents that live in family groups in burrows, which are visible on satellite images. In great gerbil populations an abundance threshold exists, above which plague can spread causing epizootics. The spatial distribution of the host species is thought to influence the plague dynamics, such as the direction of plague spread, however no detailed analysis exists on the possible functional or structural corridors and barriers that are present in this population and landscape. This study aims to fill that gap. Methods Three 20 by 20 km areas with known great gerbil burrow distributions were used to analyse the spatial distribution of the burrows. Object-based image analysis was used to map the landscape at several scales, and was linked to the burrow maps. A novel object-based method was developed – the mean neighbour absolute burrow density difference (MNABDD) – to identify the optimal scale and evaluate the efficacy of using landscape objects as opposed to square cells. Multiple regression using raster maps was used to identify the landscape-ecological variables that explain burrow density best. Functional corridors and barriers were mapped using burrow density thresholds. Cumulative resistance of the burrow distribution to potential disease spread was evaluated using cost distance analysis. A 46-year plague surveillance dataset was used to evaluate whether plague spread was radially symmetric. Results The burrow distribution was found to be non-random and negatively correlated with Greenness, especially in the floodplain areas. Corridors and

  12. The effect of a walking program on perceived benefits and barriers to exercise in postmenopausal African American women.

    Science.gov (United States)

    Williams, Bernadette R; Bezner, Janet; Chesbro, Steven B; Leavitt, Ronnie

    2006-01-01

    Rates of exercise participation among African Americans is low. Identifying and overcoming perceived benefits/ barriers unique to African American women (AAW) may increase their exercise participation. The purpose of this study was to describe perceived benefits/barriers to exercise in AAW before and after participation in a walking program. Thirty-five postmenopausal AAW participated in a 7-week structured walking program with 2 walking goals. Perceived benefits and barriers to exercise were assessed using the Exercise Benefits/Barriers Scale at the beginning and end of the program. Participants engaged in a postintervention interview to further assess benefits/barriers to exercise participation. Perceived benefits/barriers to exercise did not change significantly with participation in a walking program. Lack of time due to work and family responsibilities affected achievement of the brisk walking goal. Postmenopausal AAW in this study strongly believed in the benefits of exercising and had increased levels of participation in a walking program when lack of time was not a barrier. Overcoming this barrier is the true challenge to health care professionals.

  13. Why do not more prisoners participate in adult education? An analysis of barriers to education in Norwegian prisons

    Science.gov (United States)

    Manger, Terje; Eikeland, Ole Johan; Asbjørnsen, Arve

    2018-06-01

    From a lifelong learning perspective, education during incarceration is crucial for prisoners' rehabilitation. This article describes the authors' development of their Perceived Barriers to Prison Education Scale (PBPES) and examines what deters prisoners from participating in education during their incarceration, how their perceptions differ depending on gender, age, educational level, learning difficulties, length of prison sentence, and whether the prisoners express a desire to participate in education or not. Within a larger survey conducted in all Norwegian prisons among all prisoners with Norwegian citizenship, the authors focused on those who did not participate in education (n = 838). To reveal the underlying constructs that comprise perceived barriers, they hypothesised a three-factor model to which they applied confirmatory factor analysis (CFA). The analysis confirmed the model, which comprised institutional barriers (e.g. insufficient practical arrangements; lack of access to computers and to the Internet), situational barriers (e.g. education is not considered to be of help in the current situation) and dispositional barriers (e.g. having difficulties in mathematics, reading, writing and concentrating), with good fit to the data. The authors used mixed-model analyses of variance to examine differences between subgroups of prisoners. Gender, age, educational level, learning difficulties and length of prison sentence were found to influence perceived barriers. The authors also observed that prisoners who wished to participate in education were more likely than others to perceive institutional barriers and less likely to perceive situational barriers.

  14. Assessment on mechanical effect of engineering barrier system to fault movement. Research document

    International Nuclear Information System (INIS)

    Hirai, Takashi; Tanai, Kenji; Takaji, Kazuhiko; Ohnuma, Satoshi

    2003-03-01

    The objective of this report is to clarify mechanical effect of engineering barrier system to the unavoidable fault movement. From the basic policy of the second progress report by JNC, natural phenomenon which affect strongly to the geological disposal system should be avoided. However, small faults as sliprate ''C'' far from principal fault zone, are difficult to be found out completely. Therefore, it is important to evaluate the influence of these fault movements and to clarify stability and safety of the engineered barrier system. Accordingly, the effect of a rock displacement across a deposition holl was considered and the midium scale test was carried out. Then midium scale test was simulated by Finit Element Method in which the constitutive model of Tresca was adopted to analyze elastoplastic behavior of buffer material. From the result of the midium scale test and the analysis, it was realized that the buffer material diminish shear stress acting on the overpack. Further analytical study was conducted to evaluate the real scale engineered barrier system designed in the second progress report by JNC. From the study, it was appeared that stress in buffer corresponded to the stress calculated for the midium scale test model. Consequently, it was obvious that rock displacement, 80% of buffer didn't affect overpack if velocity of fault movement was under 10 cm/sec. (author)

  15. The Danish Barriers Questionnaire-II: preliminary validation in cancer pain patients

    DEFF Research Database (Denmark)

    Jacobsen, Ramune; Møldrup, Claus; Christrup, Lona Louring

    2009-01-01

    OBJECTIVE: The objective of this study was to examine the psychometric properties of the Danish version of the Barriers Questionnaire-II (DBQ-II). METHODS: The validated Norwegian version of the DBQ-II was translated into Danish. Cancer patients for the study were recruited from specialized pain...... cancer pain management. Scale two, Immune System, consisted of three items addressing the belief that pain medications harm the immune system. Scale three, Monitor, consisted of three items addressing the fear that pain medicine masks changes in one's body. Scale four, Communication, consisted of five......: The DBQ-II seems to be a reliable and valid measure of the barriers to pain management among Danish cancer patients....

  16. Socio-cultural barriers to the development of a sustainable energy system - the case of hydrogen

    DEFF Research Database (Denmark)

    Petersen, Lars Kjerulf; Andersen, Anne Holst

    Any transition to a more sustainable energy system, radically reducing greenhouse gas emissions, is bound to run in to a host of different barriers - technological and economic, but also socio-cultural. This will also be the case for any large-scale application of hydrogen as energy carrier......, especially if the system is going to be based on renewable energy sources. The aim of these research notes is to review and discuss major socio-cultural barriers to new forms of energy supply in general and to hydrogen specifically. Reaching sufficient reductions in greenhouse gas emissions may require more...

  17. Market failures and barriers as a basis for clean energy policies

    International Nuclear Information System (INIS)

    Brown, M.A.

    2001-01-01

    This paper provides compelling evidence that large-scale market failures and barriers prevent consumers in the United States from obtaining energy services at least cost. Assessments of numerous energy policies and programs suggest that public interventions can overcome many of these market obstacles. By articulating these barriers and reviewing the literature on ways of addressing them, this paper provides a strong justification for the policy portfolios that define the ''Scenarios for a Clean Energy Future'', a study conducted by five National Laboratories. These scenarios are described in other papers published in this special issue of Energy Policy. (author)

  18. Molecular scale

    Directory of Open Access Journals (Sweden)

    Christopher H. Childers

    2016-03-01

    Full Text Available This manuscript demonstrates the molecular scale cure rate dependence of di-functional epoxide based thermoset polymers cured with amines. A series of cure heating ramp rates were used to determine the influence of ramp rate on the glass transition temperature (Tg and sub-Tg transitions and the average free volume hole size in these systems. The networks were comprised of 3,3′-diaminodiphenyl sulfone (33DDS and diglycidyl ether of bisphenol F (DGEBF and were cured at ramp rates ranging from 0.5 to 20 °C/min. Differential scanning calorimetry (DSC and NIR spectroscopy were used to explore the cure ramp rate dependence of the polymer network growth, whereas broadband dielectric spectroscopy (BDS and free volume hole size measurements were used to interrogate networks’ molecular level structural variations upon curing at variable heating ramp rates. It was found that although the Tg of the polymer matrices was similar, the NIR and DSC measurements revealed a strong correlation for how these networks grow in relation to the cure heating ramp rate. The free volume analysis and BDS results for the cured samples suggest differences in the molecular architecture of the matrix polymers due to cure heating rate dependence.

  19. Implementation of renewable energy technologies - Opportunities and barriers. Ghana country study

    Energy Technology Data Exchange (ETDEWEB)

    Edjekumhene, I.; Atakora, S.B.; Atta-Konadu, R.; Brew-Hammond, A. [Kumasi Inst. og Technology and Environment (Ghana)

    2001-07-01

    This report presents the experience of Ghana in the development, utilisation and promotion of Renewable Energy Technologies (RETs). The report gives a general overview of the state of RETs, describes past/existing institutional, regulatory and policy framework, identifies key barriers to and opportunities for RETs, and recommends directional changes needed to remove barriers and promote wide-scale adoption of RETs in Ghana. A total of eight RETs - biomass-fired dryers, sawdust stoves, sawdust briquette, biogas, solar crop dryer, solar water heater, solar water pump and small hydro power - are covered in the report. Analyses of barriers to the eight RETs are carried out using a framework approach that categorises barriers into socio-technical, economic and crosscutting barriers. Financial analyses, as opposed to economic analyses, have been carried out for all the selected RETs. The report also incorporates stake holders' perspectives and views on barriers and how they can be removed. Ghana is endowed with several renewable energy resources like solar radiation, small hydro, biomass, and wind. Exploitation of Ghana's renewable energy resources has been carried out under two main policy regimes - PND Law 62 (1983) and the Energy Sector Development Programme (ESDP). Several measures and instruments have been employed in the implementation of renewable energy policies. The main measures used are research and development, information and eduction, and some normative measures (like the passing of PNDC Law 62 and the Energy Commission Law). Some economic instruments, such as subsidies, taxes, pricing, financing and duty waiver/reduction, have been used as well but only to a limited extent. The effective development, implementation and dissemination of all the RETs studied are hampered by several barriers, which can be grouped into three main categories - Socio-technical barriers, economic barriers and crosscutting barriers. Socio-technical barriers refer to

  20. Implementation of renewable energy technologies - Opportunities and barriers. Ghana country study

    Energy Technology Data Exchange (ETDEWEB)

    Edjekumhene, I; Atakora, S B; Atta-Konadu, R; Brew-Hammond, A [Kumasi Inst. og Technology and Environment (Ghana)

    2001-07-01

    This report presents the experience of Ghana in the development, utilisation and promotion of Renewable Energy Technologies (RETs). The report gives a general overview of the state of RETs, describes past/existing institutional, regulatory and policy framework, identifies key barriers to and opportunities for RETs, and recommends directional changes needed to remove barriers and promote wide-scale adoption of RETs in Ghana. A total of eight RETs - biomass-fired dryers, sawdust stoves, sawdust briquette, biogas, solar crop dryer, solar water heater, solar water pump and small hydro power - are covered in the report. Analyses of barriers to the eight RETs are carried out using a framework approach that categorises barriers into socio-technical, economic and crosscutting barriers. Financial analyses, as opposed to economic analyses, have been carried out for all the selected RETs. The report also incorporates stake holders' perspectives and views on barriers and how they can be removed. Ghana is endowed with several renewable energy resources like solar radiation, small hydro, biomass, and wind. Exploitation of Ghana's renewable energy resources has been carried out under two main policy regimes - PND Law 62 (1983) and the Energy Sector Development Programme (ESDP). Several measures and instruments have been employed in the implementation of renewable energy policies. The main measures used are research and development, information and eduction, and some normative measures (like the passing of PNDC Law 62 and the Energy Commission Law). Some economic instruments, such as subsidies, taxes, pricing, financing and duty waiver/reduction, have been used as well but only to a limited extent. The effective development, implementation and dissemination of all the RETs studied are hampered by several barriers, which can be grouped into three main categories - Socio-technical barriers, economic barriers and crosscutting barriers. Socio-technical barriers refer to resource