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Sample records for reinforced soil retaining

  1. Fiber reinforced composites orthodontic retainers.

    PubMed

    Lucchese, A; Manuelli, M; Bassani, L; Albertini, P; Matarese, G; Perillo, L; Gastaldi, G; Gherlone, E F

    2015-12-01

    Retention is the phase of orthodontic treatment that attempts to hold teeth in their corrected positions after orthodontic therapy is completed. The aim of this study was to consider fiber-reinforced composites (FRC) as a possible alternative to conventional multistranded stainless steel wire for retention through SEM analysis. Two different FRC orthodontic retainers were investigated, i.e. Everstick® (Stick Tech Ltd, Turku, Finland) (type A, 24 samples), with a diameter of 0.76 mm made of glass fibers and a Young's modulus of elasticity of 28 gpa, and Ribbond® (Ribbond, Inc., Seattle, Washington, WA, USA) (type B, 24 samples), with ultra high molecular weight and with an high Young's modulus of elasticity by polyethylene fibers cold treated with plasma gas. Six groups were created: control groups A1 and B1, composed by 8 type A and 8 type B samples without impregnation and only with fluid resin before curing; groups A2 and B2, composed respectively by 8 type A and 8 type B samples impregnated with fluid resin Heliobond for 6 seconds; groups A3 and B3, composed respectively by 8 type A and 8 type B samples impregnated with fluid resin Heliobond for 6 minutes before curing. Cross- and lengthwise SEM analysis of the sectioned samples made showed that fiber without impregnation with fluid resin, before curing, showed interwoven and straight directed cylindrical fibers. The SEM analysis denoted that the two types of fiber shows structural characteristics differing in dimension, number, diameter and orientation of FRC without a preliminary treatment through impregnation of the fibers with fluid resin. An impregnation time of 6 seconds could considerably reduced voids, crazes and microcracks of the fibers, making them more resistant to the other oral and bacterial agents. A larger time of impregnation (6 minutes), with fluid resin before hardening, further enhances the morphological characteristics of the FRC.

  2. Seismic performance of geosynthetic-soil retaining wall structures

    NASA Astrophysics Data System (ADS)

    Zarnani, Saman

    Vertical inclusions of expanded polystyrene (EPS) placed behind rigid retaining walls were investigated as geofoam seismic buffers to reduce earthquake-induced loads. A numerical model was developed using the program FLAC and the model validated against 1-g shaking table test results of EPS geofoam seismic buffer models. Two constitutive models for the component materials were examined: elastic-perfectly plastic with Mohr-Coulomb (M-C) failure criterion and non-linear hysteresis damping model with equivalent linear method (ELM) approach. It was judged that the M-C model was sufficiently accurate for practical purposes. The mechanical property of interest to attenuate dynamic loads using a seismic buffer was the buffer stiffness defined as K = E/t (E = buffer elastic modulus, t = buffer thickness). For the range of parameters investigated in this study, K ≤50 MN/m3 was observed to be the practical range for the optimal design of these systems. Parametric numerical analyses were performed to generate design charts that can be used for the preliminary design of these systems. A new high capacity shaking table facility was constructed at RMC that can be used to study the seismic performance of earth structures. Reduced-scale models of geosynthetic reinforced soil (GRS) walls were built on this shaking table and then subjected to simulated earthquake loading conditions. In some shaking table tests, combined use of EPS geofoam and horizontal geosynthetic reinforcement layers was investigated. Numerical models were developed using program FLAC together with ELM and M-C constitutive models. Physical and numerical results were compared against predicted values using analysis methods found in the journal literature and in current North American design guidelines. The comparison shows that current Mononobe-Okabe (M-O) based analysis methods could not consistently satisfactorily predict measured reinforcement connection load distributions at all elevations under both static

  3. Calcium Stabilized And Geogrid Reinforced Soil Structures In Seismic Areas

    SciTech Connect

    Rimoldi, Pietro; Intra, Edoardo

    2008-07-08

    In many areas of Italy, and particularly in high seismic areas, there is no or very little availability of granular soils: hence embankments and retaining structures are often built using the locally available fine soil. For improving the geotechnical characteristics of such soils and/or for building steep faced structures, there are three possible techniques: calcium stabilization, geogrid reinforcement, and the combination of both ones, that is calcium stabilized and reinforced soil. The present paper aims to evaluate these three techniques in terms of performance, design and construction, by carrying out FEM modeling and stability analyses of the same reference embankments, made up of soil improved with each one of the three techniques, both in static and dynamic conditions. Finally two case histories are illustrated, showing the practical application of the above outlined techniques.

  4. Reinforced Soil Ammunition Magazine Full Scale Tests

    DTIC Science & Technology

    1994-08-01

    equivalent to the protection criteria required for civil defense shelters in Israel and protective structures for the IDF. The reinforced soil structure...structures as well as civil defense shelters . As the reinforced soil structure technology showed great potential, it was recommended to continue the research

  5. Effective Classroom Demonstration of Soil Reinforcing Techniques.

    ERIC Educational Resources Information Center

    Williams, John Wharton; Fox, Dennis James

    1986-01-01

    Presents a model for demonstrating soil mass stabilization. Explains how this approach can assist students in understanding the various types of soil reinforcement techniques, their relative contribution to increased soil strength, and some of their limitations. A working drawing of the model and directives for construction are included. (ML)

  6. Fracture resistance of CAD/CAM-fabricated fiber-reinforced composite denture retainers.

    PubMed

    Nagata, Kohji; Wakabayashi, Noriyuki; Takahashi, Hidekazu; Vallittu, Pekka K; Lassila, Lippo V J

    2013-01-01

    The purpose of this study was to evaluate the fracture resistance of computer-aided design/computer-assisted manufacture (CAD/CAM)-fabricated fiber-reinforced composite (FRC) denture retainers. Distal extension dentures incorporating two telescopic retainers and two molar pontics, with or without fiberglass, were fabricated by CAD/CAM or by the conventional polymerization method. The dentures were subjected to a vertical load on the second molar pontic until fracture. Within each manufacturing method, embedment of the FRC increased the mean final fracture load, suggesting the reinforcing effect of fiberglass. The polymerized dentures with FRC showed greater mean final fracture load than the CAD/CAM dentures with FRC.

  7. Interaction between reinforcing geosynthetics and soil-tire chip mixtures

    SciTech Connect

    Tatlisoz, N.; Edil, T.B.; Benson, C.H.

    1998-11-01

    The objective of the present study was to evaluate the mechanical properties of tire chips and soil-tire chip mixtures relevant to geosynthetic-reinforced earthworks. Tests were conducted to evaluate shear strength and pull-out capacity with a woven geotextile and two geogrids. Soil-tire chip mixtures made with clean sand and sandy silt were tested. These properties were then used to assess the potential advantages of using soil-tire chip backfills for geosynthetic-reinforced retaining walls and embankments. The test results show that the geosynthetic pull-out force in tire chip and soil-tire chip backfills increases with displacement--i.e., no peak pull-out force is generally obtained, at least for displacements {le}100 mm. Pull-out interaction coefficients for the chip backfills are typically greater than 1, whereas for soil-tire chip backfills are typically greater than 1, whereas for soil-tire chip backfills they typically range between 0.2 and 0.7, even though the pull-out capacity for soil-tire chip backfills is generally similar to or greater than the pull-out capacity in a soil backfill. The higher strength, lower unit weight and good backfill-geosynthetic interaction obtained with soil-tire chip backfills can result in walls requiring less geosynthetic reinforcement than walls backfilled with soil. In addition, embankments can potentially be constructed with steeper slopes and a smaller volume of material when soil-tire chip fill is used, while providing greater resistance against lateral sliding and foundation settlement.

  8. Glass fibre reinforced versus multistranded bonded orthodontic retainers: a 2 year prospective multi-centre study.

    PubMed

    Tacken, Michel P E; Cosyn, Jan; De Wilde, Peter; Aerts, Johan; Govaerts, Elke; Vannet, Bart Vande

    2010-04-01

    The objective of this study was to compare glass fibre reinforced (GFR) with multistranded bonded orthodontic retainers in terms of success rate and periodontal implications. A 2 year parallel study was conducted of 184 patients scheduled to receive bonded retainers in the upper and lower anterior segments. In three centres, the patients (mean age 14 years; 90 males and 94 females) were sequentially assigned to receive GFR retainers containing 500 unidirectional glass fibres (GFR500), 1000 unidirectional glass fibres (GFR1000), or multistranded retainers (gold standard). Retainer failures and periodontal conditions were monitored every 6 months. In a control group of 90 subjects without retainers, periodontal conditions were examined (negative control). Of the 274 recruited patients, 15 dropped out during the 2 year study period. Kaplan-Meier plots were drawn to assess survival of the different retainers. The Mantel-Cox log-rank test was used to identify significant differences in survival functions among the groups. Repeated measures analysis of variance and appropriate post hoc tests were adopted to evaluate periodontal conditions over time. GFR retainers showed unacceptably high failure rates in comparison with multistranded retainers (51 versus 12 per cent). The most significant periodontal conditions were found in patients with GFR retainers with no significant differences between the GFR500 and the GFR1000 group for any parameter at any time point. Subjects without retainers showed significantly lower levels of gingival inflammation and plaque accumulation when compared with patients in any retainer group. Multistranded retainers should remain the gold standard for orthodontic retention, although periodontal complications are common. The use of GFR retainers should be discouraged in daily practice.

  9. Seismic Effects on the Design of Geosynthetic-Reinforced Earth Retaining Structures

    DTIC Science & Technology

    1998-07-01

    geosynthetics and are subjected to cyclic motion such as that caused by earthquakes. It will examine some case studies of the performance of... geosynthetic reinforced earth retaining structures (GSRW) and review some time tested concepts dealing with both geosynthetics and seismic earth pressures

  10. Optimization of reinforced soil embankments by genetic algorithm

    NASA Astrophysics Data System (ADS)

    Ponterosso, P.; Fox, D. St. J.

    2000-04-01

    A Genetic Algorithm (GA) is described, which produces solutions to the cost optimization problem of reinforcement layout for reinforced soil slopes. These solutions incorporate different types of reinforcement within a single slope. The GA described is implemented with the aim of optimizing the cost of materials for the preliminary layout of reinforced soil embankments. The slope design method chosen is the U.K. Department of Transport HA 68/94 Design Methods for the Reinforcement of Highway Slopes by Reinforced Soil and Soil Nailing Techniques. The results confirm that there is a role for the GA in optimization of reinforced soil design.

  11. Soil reinforcement with recycled carpet wastes.

    PubMed

    Ghiassian, Hossein; Poorebrahim, Gholamreza; Gray, Donald H

    2004-04-01

    A root or fibre-reinforced soil behaves as a composite material in which fibres of relatively high tensile strength are embedded in a matrix of relatively plastic soil. Shear stresses in the soil mobilize tensile resistance in the fibres, which in turn impart greater strength to the soil. A research project has been undertaken to study the influence of synthetic fibrous materials for improving the strength characteristics of a fine sandy soil. One of the main objectives of the project is to explore the conversion of fibrous carpet waste into a value-added product for soil reinforcement. Drained triaxial tests were conducted on specimens, which were prepared in a cylindrical mould and compacted at their optimum water contents. The main test variables included the aspect ratio and the weight percentage of the fibrous strips. The results clearly show that fibrous inclusions derived from carpet wastes improve the shear strength of silty sands. A model developed to simulate the effect of the fibrous inclusions accurately predicts the influence of strip content, aspect ratio and confining pressure on the shear strength of reinforced sand.

  12. Dynamic Response of Reinforced Soil Systems. Volume 1. Report

    DTIC Science & Technology

    1993-03-01

    types of structures. To design blast-protective structures usiiig reinforced soil, the dynamic response characteristics and analytical theory of...the properties of reinforced soil under static loading condition, little work has been carried out to determine reinforced soil properties or theory ...40 2. Deformation Theories .. . .. .. . . . . .. . .. . 4k 3. Incremental Theories ..... ..... ................. 42 4. Endochronic Theories

  13. Constitutive modelling of a reinforced soil using hierarchical model

    NASA Astrophysics Data System (ADS)

    Varadarajan, A.; Sharma, K. G.; Soni, K. M.

    1999-03-01

    Drained triaxial tests are conducted on natural and reinforced sand under various stress paths. Direct shear tests and pull-out tests are conducted on soil-reinforcement interface and on reinforcement, respectively. The effects of two types of reinforcement, viz, woven and non-woven geotextile and number of layers of reinforcement are investigated. Hierarchical single surface model is used to depict the behaviour of natural and reinforced soil by treating the soil as a single composite material and by considering soil, reinforcement and interface as independent elements. It is shown that the material parameters are very much affected by the type and the number of layers of reinforcement. The hierarchical model provides satisfactory prediction for both natural and reinforced soil.

  14. Analytical and experimental investigation of soil reinforcing

    NASA Astrophysics Data System (ADS)

    Holtz, R. D.; Harr, M. E.

    1983-10-01

    Significant improvements in the capacity and service life of reinforced earth structures require an improved understanding of the fundamental behavior of these systems. Both experimental and analytical investigations were carried out to develop models for the interaction of geotextile-type reinforcement and granular soils. Reinforcement configurations and systems investigated were thought to be applicable to alternate launch and recovery surfaces (ALRS). Model ALRS systems using geotextiles and geogrids as reinforcement were tested in the laboratory in a variety of configurations. These were loaded to failure, quasi-statically, by both plane strain and axisymmetric rigid plates. Load-deformation characteristics as well as the shape of the deflected basin are reported. Significant increases in bearing capacity and modulus of subgrade reaction as a function of depth and number of layers of reinforcement were observed. However, there was a decrease in improvement as the depth to the first layer increased. Edge fixity conditions were found to be relatively unimportant, and the benefit of multiple-reinforcement layers was greater if the depth and spacing were small compared to the diameter of the loaded area. Surprisingly, little difference was observed in the response of the geogrids and geotextiles, probably because sand was used in the experiments. Geometric scaling of bearing capacity, based on the diameters of the loaded areas, was not possible.

  15. Working stress design method for reinforced soil walls

    SciTech Connect

    Ehrlich, M. ); Mitchell, J.K. )

    1994-04-01

    A method for the internal design of reinforced soil walls based on working stresses is developed and evaluated using measurements from five full-scale structures containing a range of reinforcement types. It is shown that, in general, the stiffer the reinforcement system and the higher the stresses induced during compaction, the higher are the tensile stresses that must be resisted by the reinforcements. Unique features of this method, compared to currently used reinforced soil wall design methods, are that it can be applied to all types of reinforcement systems, reinforcement and soil stiffness properties are considered, and backfill compaction stresses are taken explicitly into account. The method can be applied either analytically or using design charts. A design example is included.

  16. Two-year survival analysis of twisted wire fixed retainer versus spiral wire and fiber-reinforced composite retainers: a preliminary explorative single-blind randomized clinical trial

    PubMed Central

    Sobouti, Farhad; Rakhshan, Vahid; Saravi, Mahdi Gholamrezaei; Zamanian, Ali

    2016-01-01

    Objective Traditional retainers (both metal and fiber-reinforced composite [FRC]) have limitations, and a retainer made from more flexible ligature wires might be advantageous. We aimed to compare an experimental design with two traditional retainers. Methods In this prospective preliminary clinical trial, 150 post-treatment patients were enrolled and randomly divided into three groups of 50 patients each to receive mandibular canine-to-canine retainers made of FRC, flexible spiral wire (FSW), and twisted wire (TW). The patients were monitored monthly. The time at which the first signs of breakage/debonding were detected was recorded. The success rates of the retainers were compared using chi-squared, Kaplan-Meier, and Cox proportional-hazard regression analyses (α = 0.05). Results In total, 42 patients in the FRC group, 41 in the FSW group, and 45 in the TW group completed the study. The 2-year failure rates were 35.7% in the FRC group, 26.8% in the FSW group, and 17.8% in the TW group. These rates differed insignificantly (chi-squared p = 0.167). According to the Kaplan-Meier analysis, failure occurred at 19.95 months in the FRC group, 21.37 months in the FSW group, and 22.36 months in the TW group. The differences between the survival rates in the three groups were not significant (Cox regression p = 0.146). Conclusions Although the failure rate of the experimental retainer was two times lower than that of the FRC retainer, the difference was not statistically significant. The experimental TW retainer was successful, and larger studies are warranted to verify these results. PMID:27019825

  17. Evaluation of the cytotoxicity of fiber reinforced composite bonded retainers and flexible spiral wires retainers in simulated high and low cariogenic environments

    PubMed Central

    Jahanbin, Arezoo; Shahabi, Mostafa; Ahrari, Farzaneh; Bozorgnia, Yasaman; Shajiei, Arezoo; Shafaee, Hooman; Afshari, Jalil Tavakkol

    2015-01-01

    Objectives: The aim of this study was to evaluate the cytotoxic effects of fiber reinforced composite bonded retainers in comparison with flexible spiral wires (FSWs) under high and low cariogenic-simulated environments using human oral fibroblasts. Materials and Methods: Four types of bonded retainers were evaluated: (1) reinforced with glass fibers: Interlig (Angelus), (2) reinforced with polyethylene fibers: Connect (Kerr), (3) reinforced with quartz fibers: Quartz Splint UD (RTD), and (4) FSW. Twenty specimens of each sample group were prepared with the same surface area and halved. Next, half of them were placed in a high cariogenic environment 60 min in 10% lactic acid 3 times a day and remained in Fusayama Meyer artificial saliva for the rest of the day) and the other half were placed in a low cariogenic environment 20 min in 10% lactic acid 3 times a day and remained in Fusayama Meyer artificial saliva for the rest of the day) for 1, 7 and 30 days. Cell viability was assessed by MTT assay. Data were analyzed using SPSS software (α =0.05). Results: During the 1st month, cytotoxicity reduced gradually. In the low cariogenic-simulated environment, the cytotoxicity of all of the groups were reported to be mild at day 30 and the difference between them was significant (P = 0.016). In the same period in the high cariogenic-simulated environment, the cytotoxicity of Connect and Quartz Splint was mild, and they had lower cytotoxicity than the other groups. Meanwhile, Interlig had moderate (52%) and FSW had severe cytotoxicity (22%) and the difference between the groups was also significant (P = 0.000). Conclusions: FSW retainers are not recommended in those at high-risk for dental caries. However, in those at low-risk, there is no difference from the standpoint of cytotoxicity. PMID:25657987

  18. Adhesive properties of bonded orthodontic retainers to enamel: stainless steel wire vs fiber-reinforced composites.

    PubMed

    Foek, Dave Lie Sam; Ozcan, Mutlu; Krebs, Eliza; Sandham, Andrew

    2009-10-01

    The objectives of this study were to compare the bond strength of a stainless steel orthodontic wire vs various fiber-reinforced composites (FRC) used as orthodontic retainers on enamel, analyze the failure types after debonding, and investigate the influence of different application procedures of stainless steel wires on bond strength. Caries-free, intact human mandibular incisors (N = 80, n = 10 per group) were selected and randomly distributed into 8 groups. After etching with 37% H3PO4 for 30 s, rinsing and drying, bonding agent (Stick Resin) was applied and light polymerized. Then one of the following FRC materials was applied on the flowable composite (Stick Flow) using standard molds: group 1: Angelus Fibrex Ribbon; group 2: DentaPreg Splint; group 3: ever-Stick Ortho; group 4: Ribbond. In group 5, Quad Cat Wire was applied in the same manner as in FRC groups. In group 6, after applying bonding agent (Stick Resin), Quad Cat Wire was placed directly on the tooth surface and covered with Stick Flow composite. In group 7, after bonding agent (Heliobond) was applied, Quad Cat Wire was placed directly on the tooth surface and covered with Tetric Flow composite. In group 8, after applying bonding agent (Heliobond) and polymerization, Tetric Flow composite was applied, not polymerized, and Quad Cat Wire was placed and covered with Tetric Flow again. Specimens were thermocycled for 6000 cycles between 5 degrees C and 55 degrees C and loaded in a universal testing machine under shear stress (crosshead speed: 1 mm/min) until debonding occurred. The failure sites were examined under an optical light microscope. Data were analyzed using one-way ANOVA and the Tukey-Kramer adjustment test (alpha = 0.05). Significant differences were found between the groups (p = 0.0011) (ANOVA). Bond strength results did not significantly differ either between the FRC groups (groups 1 to 4) (6.1 +/- 2.5 to 8.4 +/- 3.7 MPa) (p > 0.05) or the wire groups (groups 5 to 8) (10.6 +/- 3.8 to 14

  19. Underground barrier construction apparatus with soil-retaining shield

    DOEpatents

    Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.

    1998-08-04

    An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 17 figs.

  20. Underground barrier construction apparatus with soil-retaining shield

    DOEpatents

    Gardner, Bradley M.; Smith, Ann Marie; Hanson, Richard W.; Hodges, Richard T.

    1998-01-01

    An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

  1. [Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].

    PubMed

    Petrikas, O A; Voroshilin, Iu G; Petrikas, I V

    2013-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (p<0.05) (a dual wing + horizontal groove 222±9 N). The highest fracture strengths were observed with dual wing + occlusal rest FPDs: 250±10 N compared to inlay-retained FPDs (p<0.001) and wing-retained FPDs (p<0.001). FEA showed more favorable stress distributions within the tooth/restoration complex for dual wing retainers+ occlusal rest FPDs. There was stress concentration around connectors and retainers near connectors. A dual-wing retainer with occlusal rest is the optimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs.

  2. Smart timber bridge on geosynthetic reinforced soil (GRS) abutments

    Treesearch

    Adam Senalik; James P. Wacker; Travis K. Hosteng; John Hermanson

    2017-01-01

    Recently, Buchanan County, Iowa, has cooperated with the U.S. Federal Highway Administration (FHWA), USDA Forest Service, Forest Products Laboratory (FPL), and Iowa State University’s Bridge Engineering Center (ISU–BEC) to initiate a project involving the construction and monitoring of a glued-laminated (glulam) timber superstructure on geosynthetic reinforced soil (...

  3. Efficacy of Esthetic Retainers: Clinical Comparison between Multistranded Wires and Direct-Bond Glass Fiber-Reinforced Composite Splints

    PubMed Central

    Scribante, Andrea; Sfondrini, Maria Francesca; Broggini, Simona; D'Allocco, Marina; Gandini, Paola

    2011-01-01

    The purpose of this longitudinal prospective randomized study was to evaluate the reliability of two different types of orthodontic retainers in clinical use: a multistrand stainless steel wire and a polyethylene ribbon-reinforced resin composite. Moreover the level of satisfaction of the patient about the esthetic result was also analyzed by means of a Visual Analogue Scale (VAS). 34 patients (9 boys and 25 girls, mean age 14.3), in the finishing phase of orthodontic treatment, were selected for the study. Since splints were applied the number, cause, and date of splint failures were recorded for each single tooth over 12 months. Statistical analysis was performed using a paired t-test, Kaplan Meier survival estimates, and the log-rank test. Kruskal Wallis test was performed to analyze VAS recordings. Differences between the bond failure rates were not statistically significant. Esthetic result of VAS was significantly higher for polyethylene ribbon-reinforced resin retainers than for stainless steel wires. PMID:22114597

  4. Bonded Orthodontic Retainer and Fixed Partial Denture Made with Fiber Reinforced Composite Resin

    PubMed Central

    Kumbuloglu, Ovul; Saracoglu, Ahmet; Cura, Cenk; User, Atilla

    2011-01-01

    Retention is the phase of orthodontic treatment which maintains teeth in their orthodontically corrected positions, following the cessation of active orthodontic tooth movement. Development of resin-impregnated, fiber-reinforced composite materials has provided the potential to develop new approaches for stabilizing teeth and replacing teeth conservatively. This case report describes the rehabilitation of a patient with orthodontic and prosthetic problems. The long-term behavior of glass fibers splint must be evaluated in clinical studies. PMID:21494395

  5. Analytical and Experimental Investigation of Soil Reinforcing.

    DTIC Science & Technology

    1983-10-01

    account full-scale test data developed at the U.S. Army Engineer (U.S.A.E.) Waterways Experiment Station. The method offers design charts that allow...Foundation Engineering , ’Vienna, voTT.2. pp. M-478, 1776. 8. Haliburton, T. A., Anglin, C. C. and Lawmaster, J. D., Selection of Geotechnical Fabrics for...pp.= 23--T, -7 .. 21. 3inquet, J. and Lee, K. L., "Bearing Capacity Analysis of Reinforced Earth Slabs," Journal of the Geotechnical Engineering

  6. Quantifying the amount of root-derived carbon retained in soil at 4 temperate deciduous forests

    NASA Astrophysics Data System (ADS)

    Matamala, R.; Jastrow, J. D.; McFarlane, K. J.; Guilderson, T. P.; Hanson, P. J.

    2013-12-01

    Soil organic matter (SOM) represents the largest reservoir of carbon (C) in terrestrial ecosystems. The contributions of root-litter sources to SOM are high but they are not well understood. In this study, our objectives were to quantify the transfer of root-derived materials into soil and to study how climate and edaphic factors affect root decomposition and root-derived C retention in soils. We established 14C-enriched root-litter manipulations at four sites representing the climatic extent of Eastern deciduous forest. These sites span a range of soil types and mean annual temperature and precipitation. We followed root decomposition and incorporation of root-derived C into soil for four years. Our results show that root mass in root decomposition bags decreased over time; the average percent root mass decomposed in Y1 was 27% of the initial mass, 42% in Y2 and 56% in Y3. Data for Y4 will also be available at the poster. Root decay constants were significantly affected by climate and edaphic factors. Soils in root incubation bags showed 14C enrichment after only one month, suggesting that root C was quickly transferred to SOM, perhaps mostly as microbial residues. After the first month, soil 14C enrichment exhibited cyclic dynamics that varied by site, which were likely related to site differences in microbial activity and edaphic factors affecting SOM stabilization. After 3 years, the average root-derived C retained in the soil varied depending on site and ranged from 5% to 25% of total root decomposition inputs. The two sites with the highest soil C concentrations were also the sites that retained the most root-derived C, at about 23% of the total inputs. At the warmest site, root retention was slightly lower than at the colder sites, but higher than the colder site with sandy soils, which only retained about 4% of the root decomposition C inputs. Data from Y4 will be available at the poster. Overall, we found that retention of root-derived materials accounted

  7. Stress distribution of single-implant-retained overdenture reinforced with a framework: A finite element analysis study.

    PubMed

    Amaral, Camilla F; Gomes, Rafael S; Rodrigues Garcia, Renata C M; Del Bel Cury, Altair A

    2017-09-28

    Studies have demonstrated the effectiveness of a single-implant-retained mandibular overdenture for elderly patients with edentulism. However, due to the high concentration of stress around the housing portion of the single implant, this prosthesis tends to fracture at the anterior region more than the 2-implant-retained mandibular overdenture. The purpose of this finite-element analysis study was to evaluate the stress distribution in a single-implant-retained mandibular overdenture reinforced with a cobalt-chromium framework, to minimize the incidence of denture base fracture. Two 3-dimensional finite element models of mandibular overdentures supported by a single implant with a stud attachment were designed in SolidWorks 2013 software. The only difference between the models was the presence or absence of a cobalt-chromium framework at the denture base between canines. Subsequently, the models were imported into the mathematical analysis software ANSYS Workbench v15.0. A mesh was generated with an element size of 0.7 mm and submitted to convergence analysis before mechanical simulation. All materials were considered to be homogeneous, isotropic, and linearly elastic. A 100-N load was applied to the incisal edge of the central mandibular incisors at a 30-degree angle. Maximum principal stress was calculated for the overdenture, von Mises stress was calculated for the attachment and implant, and minimum principal stress was calculated for cortical and cancellous bone. In both models, peak stress on the overdenture was localized at the anterior intaglio surface region around the implant. However, the presence of the framework reduced the stress by almost 62% compared with the overdenture without a framework (8.7 MPa and 22.8 MPa, respectively). Both models exhibited similar stress values in the attachment, implant, and bone. A metal framework reinforcement for a single-implant-retained mandibular overdenture concentrates less stress through the anterior area of the

  8. Use of reinforced soil wall to support steam generator transfer

    SciTech Connect

    Davie, J.R.; Wang, J.T. ); Gladstone, R.A. )

    1991-01-01

    Consumers Power Company had the two steam generators at its Palisades Nuclear Plant in Michigan replaced in November 1990. This replacement was accomplished through a 26-foot wide by 28-foot high opening cut into the wall of the containment building, about 45 feet above the original ground surface. Because this ground surface was at an approximately 3-H:1-V slope, leveling was required before replacement in order to provide access for the steam generators and adequate support for the heavy-duty gantry crane system used to transfer the generators. A 25-foot high reinforced soil wall was constructed to achieve the level surface. This paper describes the design and construction of the heavily loaded reinforced soil wall, including ground improvement measures required to obtain adequate wall stability. The performance of the wall under test loading will also be presented and discussed.

  9. Potential use of lateritic and marine clay soils as landfill liners to retain heavy metals.

    PubMed

    Chalermyanont, Tanit; Arrykul, Surapon; Charoenthaisong, Nanthanit

    2009-01-01

    The potential of a lateritic soil and a marine clay, typical of those found in hot and humid climatic regions, was assessed for use as a landfill liner material. A series of tests were conducted - physical and chemical, batch adsorption, column, hydraulic conductivity, etc., - to evaluate the heavy metal sorption capacity, chemical compatibility of hydraulic conductivity, and transport parameters of the soils. Experimental results showed that the marine clay had better adsorption capacity than that of the lateritic soil and that its hydraulic conductivity was an order of magnitude lower. In addition, the hydraulic conductivities of both soils when permeated with low concentration heavy metal solutions were below 1x10(-7)cm/s. When permeated with Cr, Pb, Cd, Zn, and Ni solutions, the retardation factors of the lateritic soil and the marine clay ranged from 10 to 98 and 37 to 165, respectively, while the diffusion coefficients ranged from 1.0x10(-5) to 7.5x10(-6) and 3.0 to 9.14x10(-7)cm2/s, respectively. For both soils, Cr and Pb were retained relatively well, while Cd, Zn, and Ni were more mobile. The marine clay had higher retardation factors and lower diffusion coefficients, and its hydraulic conductivity was more compatible with Cr solution, than that of the lateritic soil. In general, the properties of the marine clay indicate that it has significant advantages over the lateritic soil as landfill liner material.

  10. Modelling IP3 Watersheds: Determining Retained Soil Moisture Using Both Field Capacity and Topography

    NASA Astrophysics Data System (ADS)

    Soulis, E. D.; Craig, J.; Liu, G.; Fortin, V.

    2009-05-01

    An important characteristic of a distributed hydrologic model is its representation of the sub-grade processes. It has become common practice to organize the calculations of the energy and water balances on a landcover basis and to treat the watershed as a contiguous collection of categorized landscape elements. These supply runoff to micro drainage systems that in turn deliver water to major drainage systems. The storage/runoff characteristics of these elements have a direct influence on land surface processes including evaporation, infiltration, surface runoff, interflow, and recharge. Part of the IP3 modelling effort is to identify the key processes occurring in the elements for varying landscape types and how to best incorporate the conceptualization of each process into mathematical models. In many cases, soil drainage processes may be represented using a series of sloping soil layers that are subject to infiltration, percolation, and downslope interflow. To be successful, such an approach requires a means to calculate the distribution of retained water in the sloping soil horizons as a function of time. Traditionally soil moisture is represented by conceptually sound but somewhat arbitrary functions. For example, retained water was first unconstrained in WATDRAIN, the soil moisture module in MESH. Then, in WATDRAIN2, field capacity was used as a limit, defined as the water remaining in the soil when suction is at one third atmosphere. In both cases the model had difficulty in dry conditions. A new approach is proposed for near surface flow that includes an approximate solution to Richard's Equation for a sloped aquifer for both saturated and unsaturated conditions, as well as a definition of field capacity based on soil properties and topography. The results for field capacity are compared with the original data sets used to determine the one third atmosphere definition. The impact of this revised approach on simulation results is demonstrated.

  11. Clinical evaluation of bond failures and survival between mandibular canine-to-canine retainers made of flexible spiral wire and fiber-reinforced composite

    PubMed Central

    Sfondrini, Maria F.; Fraticelli, Danilo; Castellazzi, Linda; Gandini, Paola

    2014-01-01

    Objectives: The purpose of this longitudinal prospective randomized study was to evaluate the clinical reliability of two different types of postorthodontic treatment retainers: a silanised-treated glass fibers-reinforced resin composite (FRC) and a directly bonded multistranded stainless steel wire. The hypothesis of the study was to assess if significant differences are present between failure rates of the two retainers. Study Design: This prospective study was based on an assessment of 87 patients (35 men and 52 women),with an average age of 24 years who required a lower arch fixed retainer after orthodontic treatment. Patients were divided in two groups. Assignment was carried out with random tables. A follow-up examination was carried out once a month. The number, cause, and date of single bond adhesive failures were recorded for both retainers over 12 months. Teeth that were rebonded after failure were not included in the success analysis. Statistical analysis was performed by means of a Fisher’s exact test, Kaplan-Meier survival estimates, and log rank test. Results: Bond failure rate was significantly higher (P=0.0392) for multistranded metallic wire than for FRC. Conclusions: Glass fiber-reinforced resin composite retainers and multistranded metallic wires showed no significant difference in single bond failure rates over a one-year follow up. Key words:Fiber reinforced composite, fixed retention, multistranded wire, orthodontics, retainer, splint. PMID:24790714

  12. Cultivated Sub-Populations of Soil Microbiomes Retain Early Flowering Plant Trait.

    PubMed

    Panke-Buisse, Kevin; Lee, Stacey; Kao-Kniffin, Jenny

    2017-02-01

    The collection of microorganisms found in the root zone of soil, termed the rhizosphere microbiome, has been shown to impact plant growth and development. Here, we tease apart the function of the cultivable portion of the microbiome from the whole microbiome in retaining plant traits modified through artificial selection on flowering time. Specifically, the whole microbiome associated with earlier flowering time of Arabidopsis thaliana was cultivated on four types of solid media to create cultivated fractions of the microbiome. These cultivated microbiomes were subsequently preserved in glycerol, frozen, and revived to yield a portion of the cultivable fraction to compare (1) whole microbiome, (2) cultivable microbiome, and (3) revived, cultivable microbiome controls on early flowering time. Plants grown in soils inoculated with bacteria grown on 25 % Luria broth and 10 % tryptic soy agar retained the early flowering trait. An increase in leaf biomass with two of the cultivated microbiomes (49.4 and 38.5 %) contrasted the lowered biomass effect of the whole microbiome. Inoculation with the cultivated microbiomes that were cryopreserved in glycerol showed no effect on flowering time or leaf biomass. The results indicate that the cultivable portion of a plant's microbiome retains the early flowering effect in A. thaliana, but cryopreservation of the cultivated microbiomes disrupts the microbial effects on flowering time. Furthermore, the contrasting effects on leaf biomass (an indirect response from selection on early flowering time), seen with the whole microbiome versus the cultivable portion, suggests versatility in using cultivation methods to modify multiple traits of plants.

  13. Plastic Fibre Reinforced Soil Blocks as a Sustainable Building Material

    NASA Astrophysics Data System (ADS)

    Prasad, C. K. Subramania; Nambiar, E. K. Kunhanandan; Abraham, Benny Mathews

    2012-10-01

    Solid waste management, especially the huge quantity of waste plastics, is one of the major environmental concerns nowadays. Their employability in block making in the form of fibres, as one of the methods of waste management, can be investigated through a fundamental research. This paper highlights the salient observations from a systematic investigation on the effect of embedded fibre from plastic waste on the performance of stabilised mud blocks. Stabilisation of the soil was done by adding cement, lime and their combination. Plastic fibre in chopped form from carry bags and mineral water bottles were added (0.1% & 0.2% by weight of soil) as reinforcement. The blocks were tested for density, and compressive strength, and observed failure patterns were analysed. Blocks with 0.1% of plastic fibres showed an increase in strength of about 3 to 10%. From the observations of failure pattern it can be concluded that benefits of fibre reinforcement includes both improved ductility in comparison with raw blocks and inhibition of crack propogation after its initial formation.

  14. Soil moisture causes dynamic adjustments to root reinforcement that reduce slope stability

    Treesearch

    Tristram C. Hales; Chelcy F. Miniat

    2017-01-01

    In steep soil-mantled landscapes, the initiation of shallow landslides is strongly controlled by the distribution of vegetation, whose roots reinforce the soil. The magnitude of root reinforcement depends on the number, diameter distribution, orientation and the mechanical properties of roots that cross potential failure planes. Understanding how these...

  15. [Effects and mechanisms of plant roots on slope reinforcement and soil erosion resistance: a research review].

    PubMed

    Xiong, Yan-Mei; Xia, Han-Ping; Li, Zhi-An; Cai, Xi-An

    2007-04-01

    Plant roots play an important role in resisting the shallow landslip and topsoil erosion of slopes by raising soil shear strength. Among the models in interpreting the mechanisms of slope reinforcement by plant roots, Wu-Waldron model is a widely accepted one. In this model, the reinforced soil strength by plant roots is positively proportional to average root tensile strength and root area ratio, the two most important factors in evaluating slope reinforcement effect of plant roots. It was found that soil erosion resistance increased with the number of plant roots, though no consistent quantitative functional relationship was observed between them. The increase of soil erosion resistance by plant roots was mainly through the actions of fiber roots less than 1 mm in diameter, while fiber roots enhanced the soil stability to resist water dispersion via increasing the number and diameter of soil water-stable aggregates. Fine roots could also improve soil permeability effectively to decrease runoff and weaken soil erosion.

  16. Effects of Particle Size on the Shear Behavior of Coarse Grained Soils Reinforced with Geogrid.

    PubMed

    Kim, Daehyeon; Ha, Sungwoo

    2014-02-07

    In order to design civil structures that are supported by soils, the shear strength parameters of soils are required. Due to the large particle size of coarse-grained soils, large direct shear tests should be performed. In this study, large direct shear tests on three types of coarse grained soils (4.5 mm, 7.9 mm, and 15.9 mm) were performed to evaluate the effects of particle size on the shear behavior of coarse grained soils with/without geogrid reinforcements. Based on the direct shear test results, it was found that, in the case of no-reinforcement, the larger the maximum particle size became, the larger the friction angle was. Compared with the no-reinforcement case, the cases reinforced with either soft geogrid or stiff geogrid have smaller friction angles. The cohesion of the soil reinforced with stiff geogrid was larger than that of the soil reinforced with soft geogrid. The difference in the shear strength occurs because the case with a stiff geogrid has more soil to geogrid contact area, leading to the reduction in interlocking between soil particles.

  17. Reinforcement of an existing implant-retained complete dental prosthesis for use in compensatory techniques by a patient missing an upper limb.

    PubMed

    Baker, Philip S; Nahlah, Esam Abou

    2012-05-01

    The purpose of this article is to describe the adaptation of a method suggested for prevention of fractures of partial removable dental prostheses to the reinforcement of an existing implant-retained fixed complete dental prosthesis (IRFCDP). The patient, an upper limb amputee, had subjected the original IRFCDP to parafunctional forces generated from use as a replacement hand in a compensatory technique commonly taught in rehabilitation. Advantages of the technique are that it provides an alternative to remaking the entire prosthesis, which was otherwise satisfactory; it adapts to a variety of situations involving anterior tooth reinforcement; and it offers a potential solution to anterior prosthetic tooth damage caused by other types of parafunction. It may also be adaptable to the reinforcement of other types of prostheses. A disadvantage is the possible need to provide a new interim prosthesis or modify an existing one while laboratory repair procedures are completed. Following reinforcement of the IRFCDP, no tooth damage was evident after one year of use. (J Prosthet Dent 2012;107:343-345).

  18. Borate-Rhamnogalacturonan II Bonding Reinforced by Ca2+ Retains Pectic Polysaccharides in Higher-Plant Cell Walls1

    PubMed Central

    Kobayashi, Masaru; Nakagawa, Hironobu; Asaka, Tomoyuki; Matoh, Toru

    1999-01-01

    The extent of in vitro formation of the borate-dimeric-rhamnogalacturonan II (RG-II) complex was stimulated by Ca2+. The complex formed in the presence of Ca2+ was more stable than that without Ca2+. A naturally occurring boron (B)-RG-II complex isolated from radish (Raphanus sativus L. cv Aokubi-daikon) root contained equimolar amounts of Ca2+ and B. Removal of the Ca2+ by trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid induced cleavage of the complex into monomeric RG-II. These data suggest that Ca2+ is a normal component of the B-RG-II complex. Washing the crude cell walls of radish roots with a 1.5% (w/v) sodium dodecyl sulfate solution, pH 6.5, released 98% of the tissue Ca2+ but only 13% of the B and 22% of the pectic polysaccharides. The remaining Ca2+ was associated with RG-II. Extraction of the sodium dodecyl sulfate-washed cell walls with 50 mm trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid, pH 6.5, removed the remaining Ca2+, 78% of B, and 49% of pectic polysaccharides. These results suggest that not only Ca2+ but also borate and Ca2+ cross-linking in the RG-II region retain so-called chelator-soluble pectic polysaccharides in cell walls. PMID:9880361

  19. Is Regional Root Reinforcement Controlled by Soil Moisture Variability?

    NASA Astrophysics Data System (ADS)

    Hales, T.; Ford, C. R.

    2011-12-01

    Climate change will alter the amount, type (i.e., snow vs. rain), and timing of precipitation that controls many hazardous Earth surface processes, including debris flows. Most GCMs agree that as climate warms the frequency of extreme precipitation will increase across the globe. Debris flow events triggered by heavy precipitation will likely also increase. Precipitation also affects the resistance to debris flow initiation by controlling belowground plant hydraulic architecture (e.g. root frequency, diameter distribution, tensile strength). Quantifying the links between precipitation, below ground properties, and the processes that initiate debris flows are therefore critical to understanding future hazard. To explore these links, we conducted a field experiment in the Coweeta Hydrologic Laboratory by excavating 12 soil pits (~1 m3), from two topographies (noses, hollows), and two tree species (Liriodendron tulipifera and Betula lenta). For each species and topography, we collected all biomass from five soil depths and measured soil moisture at 30, 60, and 90cm depth. For each depth we also measured root tensile strength, root cellulose content. Where we collected soil moisture data, we also measured root and soil hydraulic conductivity. Our data show a link between soil moisture content and root biomass distribution; root biomass is more evenly distributed through the soil column in hollows compared to noses. This relationship is consistent with the hypothesis that more consistent soil moisture in hollows allows plant roots to access resources from deeper within the soil column. This physiologic control has a significant effect on root cohesion, with trees on noses (or lower average soil moisture) providing greater root cohesion close to the surface, but considerably less cohesion at depth. Root tensile strength correlated with local daily soil moisture rather than the long term differences represented by noses and hollows. Daily soil moisture affected the amount

  20. Urban parks provide ecosystem services by retaining metals and nutrients in soils.

    PubMed

    Setälä, H; Francini, G; Allen, J A; Jumpponen, A; Hui, N; Kotze, D J

    2017-08-19

    Urban greenspaces provide ecosystem services like more natural ecosystems do. For instance, vegetation modifies soil properties, including pH and soil organic matter content, yet little is known about its effect on metals. We investigated whether the accumulation and mobility of heavy metals, nutrients and carbon is affected by plant functional types (evergreen or deciduous trees, lawns) in urban parks of varying ages in southern Finland. Plant types modified soil physico-chemical parameters differently, resulting in diverging accumulation and mobility of metals and other elements in park soils. However, the effects of plant functional type depended on park age: lawns in parks of ca. 50 y old had the highest contents of Cr, Cu, Fe, Mn, Ni, and Zn, and in these, and older parks (>100 y old), contents of most metals were lowest under evergreen trees. The mobility of metals and other elements was influenced by the amount of water leached through the soils, highlighting the importance of vegetation on hydrology. Soils under evergreen trees in young parks and lawns in intermediately-aged parks were most permeable to water, and thus had high loads of Ca, Cr, Cu, Fe, Ni, tot-P and tot-N. The loads/concentrations of elements in the leachates was not clearly reflected by their content/concentration in the soil, alluding to the storage capacity of these elements in urban park soils. Our results suggest that in urban systems with a high proportion of impermeable surfaces, park soil has the potential to store nutrients and metals and provide an important ecosystem service particularly in polluted cities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Behaviour of Cohesionless Soil Reinforced with Three Dimensional Inclusions Under Plane Strain Conditions

    NASA Astrophysics Data System (ADS)

    Harikumar, M.; Sankar, N.; Chandrakaran, S.

    2015-09-01

    Since 1969, when the concept of earth reinforcing was brought about by Henry Vidal, a large variety of materials such as steel bars, tire shreds, polypropylene, polyester, glass fibres, coir and jute fibres etc. have been widely added to soil mass randomly or in a regular, oriented manner. The conventional reinforcements in use were two dimensional or planar, in the form of strips with negligible widths or in the form of sheets. In this investigation, a novel concept of multi oriented plastic reinforcement (hexa-pods) is discussed. Direct shear tests were conducted on unreinforced and reinforced dry fine, medium and coarse sands. Detailed parametric studies with respect to the effective grain size of soil (d10), normal stress (σ) and the volume ratio of hexa-pods (Vr) were performed. It was noticed that addition of hexa-pods resulted in increase in the shear strength parameters viz. peak deviatoric stresses and increased angle of internal friction. The hexa-pods also changed the brittle behaviour of unreinforced sand samples to ductile ones. Although the peak shear stress did not show a considerable improvement, the angle of internal friction improved noticeably. Addition of a single layer of reinforcement along the shear plane also reduced the post peak loss of strength and changed the soil behavior from brittle to a ductile one.

  2. Improving irrigation efficiency of sandy soils by subsurface water retaining membranes

    NASA Astrophysics Data System (ADS)

    Guber, Andrey; Smucker, Alvin; Berhanu, Samrawi

    2014-05-01

    Sustainable crop production in sandy soils is challenging due to low soil water holding capacity and high water permeability. The subsurface water retention technology (SWRT) is a relatively new long-term approach that offers precision control of water and nutrients in the root zone. However, multiple design of SWRT membrane configurations and spatial distributions require more modeling for best application in arid regions with relevant irrigation methods. The objective of this study was to define optimal geometric parameters of the SWRT membranes and the most accurate irrigation rates for corn production in sandy soils. HYDRUS-2D model, that describes two-dimensional water flow in unsaturated soil, was calibrated and validated on data in a large sand-filled lysimeter with SWRT membranes installed at different depths with different aspect ratios. The model adequately reproduced soil water content dynamics measured at 12 locations inside the sand profile. Then HYDRUS-2D simulations were repeated with different SWRT installation depths and aspect ratios. The installation depths in these simulations were 20 cm, 40 cm, and 60 cm, while the aspect ratios were 2:1, 3:1, 5:1 and 10:1. The results of simulations confirmed water holding capacity of the soil can be differentially controlled by aspect ratios of SWRT membranes. SWRT membranes with an aspect ratio of 2:1 substantially increased soil water content at 20-cm soil layer above the membrane, and this effect diminished with increasing aspect ratio of the membrane. Installation depth within the soil profile had no significant effect on water loss. The HYDRUS-2D simulations were repeated with SWRT installed at depth of 20 cm for sprinkle, surface drip and subsurface drip irrigation. Corn irrigation was triggered at pressure head of -30cm at a depth of 15 cm for all irrigation techniques. Simulated water losses by deep infiltration in sands without SWRT membranes approached 60% with approximately 15% losses when SWRT

  3. Mulch your tomatoes to fight weeds, retain soil moisture and save money

    USDA-ARS?s Scientific Manuscript database

    An on-farm experiment was conducted to determine whether different types of mulches were a cost-effective means of weed management in organic tomato production. Three mulch treatment, bare soil, straw and grass, were applied to drip-irrigated tomatoes at a depth of 7.5 cm. Weed biomass was reduced s...

  4. Study on reinforcement of soil for suppressing fugitive dust by bio-cementitious material

    NASA Astrophysics Data System (ADS)

    Zhan, Qiwei; Qian, Chunxiang

    2017-06-01

    Microbial-induced reinforcement of soil, as a new green and environmental-friendly method, is being paid extensive attention to in that it has low cost, simple operation and rapid effects. In this research, reinforcement of soil for suppressing fugitive dust by bio-cementitious material was investigated. Soil cemented by bio-cementitious material had superior mechanical properties, such as hardness, compressive strength, microstructure, wind-erosion resistance, rainfall-erosion resistance and freeze-thaw resistance. The average hardness of sandy soil, floury soil and clay soil is 18.9 º, 25.2 º and 26.1 º, while average compressive strength of samples is 0.43 MPa, 0.54 MPa and 0.69 MPa, respectively; meanwhile, the average calcite content of samples is 6.85 %, 6.09 %, and 5.96 %, respectively. Compared with the original sandy soil, floury soil and clay soil, the porosity decreases by 38.5 %, 33.7 % and 29.2 %. When wind speed is 12 m/s, the mass loss of sandy soil, floury soil and clay soil cemented by bio-cementitious material are all less than 30 g/(m2·h). After three cycles of rainfall erosion of 2.5 mm/h, the mass loss are less than 25 g/(m2·h) and the compressive strength residual ratio are more than 98.0 %. Under 25 cycles of freeze-thaw, the mass loss ratio are less than 3.0 %.

  5. Deformation Behaviors of Geosynthetic Reinforced Soil Walls on Shallow Weak Ground

    NASA Astrophysics Data System (ADS)

    Kim, You-Seong; Won, Myoung-Soo

    In this study, the fifteen-month behavior of two geosynthetic reinforced soil walls, which was constructed on the shallow weak ground, was measured and analyzed. The walls were backfilled with clayey soil obtained from the construction site nearby, and the safety factors obtained from general limit equilibrium analysis were less than 1.3 in both wall. To compare with the measured data from the real GRS walls and unreinforced soil mass, a series of finite element method (FEM) analyses on two field GRS walls and unreinforced soil mass were conducted. The FEM analysis results showed that failure plane of unreinforced soil mass was consistent with the Rankine active state, but failure plane did not occur in GRS walls. In addition, maximum horizontal displacements and shear strains in GRS walls were 50% smaller than those found in unreinforced soil mass. Modeling results such as the maximum horizontal displacements, horizontal pressure, and geosynthetic tensile strengths in GRS wall have a god agreement with the measured data. Based on this study, it could be concluded that geosynthetic reinforcement are effective to reduce the displacement of the wall face and/or the deformation of the backfill soil even if the mobilized tensile stress after construction is very small.

  6. Clinical survival of indirect, anterior 3-unit surface-retained fibre-reinforced composite fixed dental prosthesis: Up to 7.5-years follow-up.

    PubMed

    Kumbuloglu, Ovul; Özcan, Mutlu

    2015-06-01

    This prospective clinical study evaluated the performance of indirect, anterior, surface-retained, fibre-reinforced-composite restorations (ISFRCR). Between June-2003 and January-2011, a total of 134 patients (83 females, 51 males, 16-68 years old) received 175 ISFRCRs (local ethical registration number: 14/9/4). All restorations were made indirectly on a plaster model using unidirectional E-glass fibres (everStick C&B, StickTech) in combination with a laboratory resin composite (Dialogue, Schütz Dental) and cemented according to the instructions of 4 resin cements [(RelyX ARC, 3M-ESPE, n=61), Bifix DC, VOCO, n=45), Variolink II (Ivoclar Vivadent, n=32) and Multilink (Ivoclar Vivadent, n=37)]. After baseline recordings, patients were followed at 6 months and thereafter annually up to 7.5 years. The evaluation protocol involved technical (chipping, debonding or fracture of tooth/restoration) and biological failures (caries). Mean observation period was 58 months. Altogether, 13 failures were observed [survival rate: 97.7%] (Kaplan-Meier). One catastrophic fracture [(cement: RelyX ARC), eight partial debonding (cement: Bifix DC (5), Multilink (1), RelyX ARC (1), Variolink II (1)] and four delaminations of veneering composite [(cement: Bifix DC (2), RelyX ARC (1), Multilink (1)] were observed. Except one replacement, all defective restorations were repaired or recemented. Annual failure rate of ISFRCRs was 1.73%. The survival rates with the four resin cements did not show significant differences (RelyX ARC: 98.3%; Bifix DC: 93.5%; Variolink 2: 100%; Multilink: 100%) (p=0.114). Secondary caries did not occur in any of the teeth. The 3-unit anterior indirect surface-retained resin-bonded FRC FDPs showed similar clinical survival rate when cemented with the resin cements tested. Experienced failures in general were due to debonding of the restoration or delamination of the veneering composite. 3-unit surface retained resin-bonded FRC FDPs could be considered minimal

  7. Organic materials retain high proportion of protons, iron and aluminium from acid sulphate soil drainage water with little subsequent release.

    PubMed

    Dang, Tan; Mosley, Luke M; Fitzpatrick, Rob; Marschner, Petra

    2016-12-01

    When previously oxidised acid sulphate soils are leached, they can release large amounts of protons and metals, which threaten the surrounding environment. To minimise the impact of the acidic leachate, protons and metals have to be retained before the drainage water reaches surrounding waterways. One possible amelioration strategy is to pass drainage water through permeable reactive barriers. The suitability of organic materials for such barriers was tested. Eight organic materials including two plant residues, compost and five biochars differing in feedstock and production temperature were finely ground and filled into PVC cores at 3.5 g dry wt/core. Field-collected acidic drainage water (pH 3, Al 22 mg L(-1) and Fe 48 mg L(-1)) was applied in six leaching events followed by six leaching events with reverse osmosis (RO) water (45 mL/event). Compost and biochars increased the leachate pH by up to 4.5 units and had a high retention capacity for metals. The metal and proton release during subsequent leaching with RO water was very small, cumulatively only 0.05-0.8 % of retained metals and protons. Retention was lower in the two plant residues, particularly wheat straw, which raised leachate pH by 2 units only in the first leaching event with drainage water, but had little effect on leachate pH in the following leaching events. It can be concluded that organic materials and particularly biochars and compost have the potential to be used in acid drainage treatment to remove and retain protons and metals.

  8. The self-reinforcing feedback between low soil fertility and chronic poverty

    NASA Astrophysics Data System (ADS)

    Barrett, Christopher B.; Bevis, Leah E. M.

    2015-12-01

    Most of the world's extreme poor, surviving on US$1.25 or less per day, live in rural areas and farm for a living. Many suffer chronic poverty that lasts for years or generations, rather than the transitory poverty that dominates developed, urban economies. Such chronic, structural poverty arises when an individual's productive assets -- such as their ability to work or their soils -- and the technologies and markets that transform their assets into food and income are insufficient to attain satisfactory living standards. Research reveals strong links between economic status and soil quality, and these can be self-reinforcing. For example, poor soil constrains agricultural production and household capital, and low household capital constrains investments in improving soils. Price, availability and access to credit can limit farmers' applications of nutrients, which are often the primary constraint on agricultural productivity. Soil micronutrient deficiencies can lead to dietary mineral deficiencies and negative health outcomes that further constrain productivity and household asset accumulation. Soils may also be important for smallholder resilience to stressors and shocks. For example, high-quality soil can reduce vulnerability to drought, and insurance against risk may promote investment in soils. Interventions such as fertilizer subsidies, micronutrient-fortified fertilizer and improved access to information, insurance and credit may all help break the soil-poverty cycle.

  9. Slope Root biomechanical properties and their contribution to soil reinforcement in the Landslide-prone region, the Bailong River Basin

    NASA Astrophysics Data System (ADS)

    Wang, X.; Hong, M.; Huang, Z.; Zhao, Y.; Zhang, Y.

    2016-12-01

    The presence of vegetation increases soil burden stability along slopes and therefore reduces soil erosion. The contribution of the vegetation is due to the root's mechanical (reinforcing soil shear resistance) controls on superficial landslide. The study focused on the biotechnical characteristics of the root system of commonly grown shrub species in the Bailong River Basin, one of the most serious geo-hazards regions in China. The aim of this paper is to increase the understanding on slope root biomechanical properties of different shrubs species and their contribution to soil reinforcement. Field investigations were carried out to estimate the root density distribution with depth (root area ratio). Laboratory tests were conducted to measure the root tensile breaking force and the root tensile strength. Root tensile strength measurements were carried out on single root specimens and root area ratio was estimated analyzing the whole root system. The direct shear tests were used to quantify the soil mechanical reinforcement. The improvement of soil mechanical properties obtained by the presence of shrubs was estimated using two different models(the Fibrt Bundle Model and the Finite Element Model). The results indicates that the soil-root system shear strength of Robinia pseudoacacia Linn (L.), Populus simonii (L.), Olea europaea (L.), and Zanthoxylum bungeanum (L.) increment ranged from 62.4 to 26.3 kPa and its effect on the slope stability was significantly different. Robinia pseudoacacia Linn (L.) roots presented the highest tensile strength and soil reinforcement values. Similarly at each considered depth Robinia pseudoacacia Linn (L.) showed that the highest soil reinforcement effect (1461N) while Olea europaea (L.) presented the lowest soil reinforcement effect (1329N). The finite element model shows that the FoS of Zanthoxylum bungeanum (L.) is the largest of these plants when considering root additional cohesion. This research can provide a basic theory of

  10. Covering of fiber-reinforced composite bars by adhesive materials, is it necessary to improve the bond strength of lingual retainers?

    PubMed Central

    Heravi, Farzin; Kerayechian, Navid; Moazzami, Saied Mostafa; Shafaee, Hooman; Heravi, Parya

    2015-01-01

    Objectives: The objectives were to evaluate the shear bond strength (SBS) of fiber-reinforced composite (FRC) retainers when bonding them to teeth with and without covering the FRC bars using two different adhesive systems. Materials and Methods: Hundred and twenty extracted human maxillary premolars were randomly divided into eight groups (n = 15). FRC bars (4 mm length, Everstick Ortho®, Stick Tech, Oy, Turku, Finland) were bonded to the proximal (distal) surfaces of the teeth using two different adhesives (Tetric Flow [TF, Ivoclar Vivadent, Switzerland] and resin-modified glass ionomer cement [RMGIC, ODP, Vista, CA, USA]) with and without covering with the same adhesive. Specimens were exposed to thermocycling (625 cycles per day [5–55°C, intervals: 30 s] for 8 days). The SBS test was then performed using the universal testing machine (Zwick, GMBH, Ulm, Germany). After debonding, the remaining adhesive on the teeth was recorded by the adhesive remnant index (0–3). Results: The lowest mean SBS (standard deviation) was found in the TF group without covering with adhesive (12.6 [2.11] MPa), and the highest bond strength was in the TF group with covering with adhesive (16.01 [1.09] MPa). Overall, the uncovered RMGIC (15.65 [3.57] MPa) provided a higher SBS compared to the uncovered TF. Covering of FRC with TF led to a significant increase in SBS (P = 0.001), but this was not true for RMGIC (P = 0.807). Thermal cycling did not significantly change the SBS values (P = 0.537). Overall, eight groups were statistically different (ANOVA test, F = 3.32, P = 0.034), but no significant differences in bond failure locations were found between the groups (Fisher's exact tests, P = 0.92). Conclusions: The present findings showed no significant differences between SBS of FRC bars with and without covering by RMGIC. However, when using TF, there was a significant difference in SBS measurements between covering and noncovering groups. Therefore, the use of RMGIC without

  11. [Species-associated differences in foliage-root coupling soil-reinforcement and anti-erosion].

    PubMed

    Liu, Fu-quan; Liu, Jing; Nao, Min; Yao, Xi-jun; Zheng, Yong-gang; Li, You-fang; Su, Yu; Wang, Chen-jia

    2015-02-01

    This paper took four kinds of common soil and water conservation plants of the study area, Caragana microphylla, Salix psammophila, Artemisia sphaerocephala and Hippophae rhamnides at ages of 4 as the research object. Thirteen indicators, i.e., single shrub to reduce wind velocity ration, shelterbelt reducing wind velocity ration, community reducing wind velocity ration, taproot tensile strength, representative root constitutive properties, representative root elasticity modulus, lateral root branch tensile strength, accumulative surface area, root-soil interface sheer strength, interface friction coefficient, accumulative root length, root-soil composite cohesive, root-soil composite equivalent friction angle, reflecting the characteristics of windbreak and roots, were chose to evaluate the differences of foliage-root coupling soil-reinforcement and anti-erosion among four kinds of plants by analytic hierarchy process (AHP) under the condition of spring gale and summer rainstorm, respectively. The results showed the anti-erosion index of foliage-root coupling was in the sequence of S. psammophila (0.841) > C. microphylla (0.454) > A. sphaerocephala (-0.466) > H. rhamnides (-0.829) in spring gale, and C. microphylla (0.841) > S. psammophila (0. 474) > A. sphaerocephala (-0.470) > H. rhamnides (-0.844) in summer rainstorm. S. psammophila could be regarded as one of the most important windbreak and anti-erosion species, while C. microphylla could be the most valuable soil and water conservation plant for the study area.

  12. Performance of improved ground and reinforced soil structures during earthquakes: Case studies and numerical analyses

    NASA Astrophysics Data System (ADS)

    Olgun, C. Guney

    The 1999 Kocaeli Earthquake (M=7.4) struck northwestern Turkey on August 17, 1999 and caused significant damage in urban areas located along Izmit Bay. The sites that suffered the greatest damages were located primarily in areas of poorest soil conditions, typically containing soft clays and silts and/or loose, liquefiable sands. Because the affected region is heavily developed with infrastructure and there is a preponderance of poor soils, a wide range of soil improvement measures had been used to mitigate anticipated earthquake damages throughout the region. Following the earthquake and significant aftershocks, Virginia Tech researchers traveled to Turkey to investigate the affected area to document geotechnical field performance. Primary focus of the Virginia tech team was given to investigating the performance of improved soil sites and reinforced soil structures. The sites were subjected to ground motions ranging from about 0.10g to 0.35g. The site locations ranged from 0 to 35 km from the zone of energy release. This dissertation presents in detail, the findings from the two most instructive sites. The investigation of these sites involved field reconnaissance, field and laboratory testing of soils, seismic analysis, numerical modeling, and other analytical work.

  13. An assessment of models that predict soil reinforcement by plant roots

    NASA Astrophysics Data System (ADS)

    Hallett, P. D.; Loades, K. W.; Mickovski, S.; Bengough, A. G.; Bransby, M. F.; Davies, M. C. R.; Sonnenberg, R.

    2009-04-01

    Predicting soil reinforcement by plant roots is fraught with uncertainty because of spatio-temporal variability, the mechanical complexity of roots and soil, and the limitations of existing models. In this study, the validity of root-reinforcement models was tested with data from numerous controlled laboratory tests of both fibrous and woody root systems. By using pot experiments packed with homogeneous soil, each planted with one plant species and grown in glasshouses with controlled water and temperature regimes, spatio-temporal variability was reduced. After direct shear testing to compare the mechanical behaviour of planted versus unplanted samples, the size distribution of roots crossing the failure surface was measured accurately. Separate tensile tests on a wide range of root sizes for each test series provided information on the scaling of root strength and stiffness, which was fitted using power-law relationships. These data were used to assess four root-reinforcement models: (1) Wu et al.'s (1979) root-reinforcement model, (2) Rip-Root fibre bundle model (FBM) proposed by Pollen & Simon (2005), (3) a stress-based FBM and (4) a strain-based FBM. For both fibrous (barley) and woody (willow) root systems, all of the FBMs provided a better prediction of reinforcement than Wu's root-reinforcement model. As FBMs simulate progressive failure of roots, they reflect reality better than the Wu model which assumes all roots break (and contribute to increased shear strength) simultaneously. However, all of the FBMs contain assumptions about the distribution of the applied load within the bundle of roots and the failure criterion. The stress-based FBM assumes the same stiffness for different sized roots, resulting in progressive failure from the largest to smallest roots. This is not observed in testing where the smallest roots fail first. The Rip-Root FBM predicts failure from smallest to largest roots, but the distribution of load between different sized roots is

  14. NERVA turbopump bearing retainer fabrication on nonmetallic retainer

    NASA Technical Reports Server (NTRS)

    Accinelli, J. B.

    1972-01-01

    The need for a low-wear, lightweight, high strength bearing retainer material with a radiation degradation threshold of 10 to the 9th power rads (C) prompted development of nonmetallic reinforced polymers of the following types: (1) polybenzimidazole, (2) polyimide, and (3) polyquinoxaline. Retainers were machined from tubular laminates (billets), including reinforcement by either glass or graphite fabric or filament. Fabrication of billets involves hot preimpregnation of the reinforcement fabric or filament with polymer followed by wrapping this prepreg over a heated mandrel to form a tube with the required thickness and length.

  15. Composting of biochars improves their sorption properties, retains nutrients during composting and affects greenhouse gas emissions after soil application

    USDA-ARS?s Scientific Manuscript database

    Biochar application to soils has been suggested to elevate nutrient sorption, improve soil fertility and reduce net greenhouse gas (GHG) emissions. We examined the impact of composting biochar together with a biologically active substrate (i.e., livestock manure-straw mixture). We hypothesized that ...

  16. Study of a tropical soil in order to use it to retain aluminum, iron, manganese and fluoride from acid mine drainage.

    PubMed

    Miguel, Miriam Gonçalves; Barreto, Rodrigo Paiva; Pereira, Sueli Yoshinaga

    2017-09-20

    The Ore Treatment Unit (UTM-Caldas), in the city of Caldas, Minas Gerais, Brazil, nowadays in decommissioning stage, was the first uranium extraction mine in Brazil. Several negative environmental impacts in the area have occurred, because of mining, treatment and beneficiation processes. Waste rock pile 4 (WRP-4) generates acid mine drainage (AMD), which is discharged in the Nestor Figueiredo retention pond (NFP). However, leakage of acid water by the NFP dam foundation has been constantly observed. Therefore, this research aimed to investigate a typical tropical soil, in order to use it as mineral liner for the NFP to minimize the leakage of acid water through the dam foundation and to retain predominant chemical species. Geotechnical, chemical and mineralogical tests were performed to characterize the soil and a column test was carried out using the acid mine drainage as contaminant, which contained aluminum (Al), manganese (Mn), iron (Fe) and fluoride (F(-)). The soil presented micro aggregation, acid pH, and low values of organic matter content and cation exchange capacity, which are characteristics of highly weathered soils. Diffusion was the predominant transport mechanism in the column test. Effluent solutions with pH less than 6.0 indicated the formation of insoluble Al-F complexes in the soil and desorption of iron and manganese at concentrations above those allowed by the Brazilian legislation. At pH greater than 6.0, the desorption of iron and manganese and release of aluminum and fluoride in the free form occurred, with concentrations also higher than the allowed by the Brazilian legislation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Analysis on the best position and the pile distance of anti-slide pile of reinforced soil slope

    NASA Astrophysics Data System (ADS)

    Pan, Jinqiu; Wang, Zhiyong; Dong, Tianxiong; Liang, Bo

    2017-04-01

    Regarding numerical calculation convergence and plastic zone through the slope as the criterion of slope instability, strength reduction method as calculating principle, the stability of soil slope was analyzed by using finite element software ABAQUS, and on the basis of analysis, the best position and pile distance of anti-slide pile of reinforced soil slope were studied. The numerical results showed that with the increasing of distance between anti-slide pile and toe position, safety coefficient raised firstly and then decreased, when the ratio between the horizontal distance of anti-slide to slope toe and horizontal distance of slope is around 0.6, which is the largest safety factor; The pile spacing had certain influence on the soil slope safety factor, with the different pile spacing, the safety factor was different. With the increase of the pile spacing, the safety factor decreased gradually.

  18. Effect of Geotextile Reinforcement on Shear Strength of Sandy Soil: Laboratory Study

    NASA Astrophysics Data System (ADS)

    Denine, Sidali; Della, Noureddine; Dlawar, Muhammed Rawaz; Sadok, Feia; Canou, Jean; Dupla, Jean-Claude

    2016-12-01

    This paper presents results of a series of undrained monotonic compression tests on loose sand reinforced with geotextile mainly to study the effect of confining stress on the mechanical behaviour of geotextile reinforced sand. The triaxial tests were performed on reconstituted specimens of dry natural sand prepared at loose relative density (Dr = 30%) with and without geotextile layers and consolidated to three levels of confining pressures 50, 100 and 200 kPa, where different numbers and different arrangements of reinforcement layers were placed at different heights of the specimens (0, 1 and 2 layers). The behaviour of test specimens was presented and discussed. Test results showed that geotextile inclusion improves the mechanical behaviour of sand, a significant increase in the shear strength and cohesion value is obtained by adding up layers of reinforcement. Also, the results indicate that the strength ratio is more pronounced for samples which were subjected to low value of confining pressure. The obtained results reveal that high value of confining pressure can restrict the sand shear dilatancy and the more effect of reinforcement efficiently.

  19. Strength, and Behavior of Steel Fiber-Reinforced Concrete and Soil Structures Interaction Studies.

    DTIC Science & Technology

    1987-06-29

    AUTHOR(S) Hon-Yim Ko 13&. TYPE OF REPORT 1 3b, IFIMI COVk:RE%. 14. DATE OF REPORT (k’r.. Mo.. Day) j 5. PAGE COUNT Final F RO 1/15/I81 TO 8/31/84j 6/29/87...GR. Fiber-Reinforced Concrete; Biaxial Tension -Compression; ___________________________ SolStucture Interaction, Numerical Modeling, Centrifuge...compression- tension loadings. A new piece of direct tension loading apparatus was designed and assembled for this study. Load history effects on the

  20. Determination of increase in shear strength of soil reinforced with plant roots

    NASA Astrophysics Data System (ADS)

    Sudan Acharya, Madhu; Alvarez Suarez, Sandra Patricia; Rauchecker, Markus

    2013-04-01

    The stability of a slope depends on the strength of the soil material comprising of the slope, the triggering factors and slope geometry. Vegetation growing on the slope can have mechanical, biological and hydrological roles which influence the strength characteristics of the material on the slope. The mechanical contributions arise from the physical interactions of either the foliage or the root system of the plant with the slope (Gray & Sotir, 1996). The plant roots increase the soil suction reducing pore water pressures, which significantly increases the cohesion (c) and also the friction angle (φ) to some extent. In an experimental investigation carried out in a highway embankment in Germany, an increase of effective cohesion from 1.1 kN/m² to 6.3 kN/m² and friction angle from 33.1° to 34.7° were observed. (Katzenbach & Werner, 2005). Considering the complex nature of influences of plants on slope stability, more field oriented experimental research works on different vegetative systems are required to quantify the role of different plants in slope stability. In the above context, in order to observe the increase in the shear strength of soil by different types of plant roots, an experiment has been carried out at the University of Natural Resources and Life Sciences (BOKU). This experiment consist of 10 wooden boxes of size 50x50x60 cm and 5 boxes of size 50x50x40 cm filled with normal soil suitable for growth of plants. The ten number of bigger size boxes are planted with acer campestre plants. In the other five boxes of smaller size, a mixed seed of 21 different grass species has been sowed. All the boxes are kept in an experimental field and regular take care is being done. The grass will be cut each year and the biomass will be measured. The undisturbed soil samples from each of these boxes in first and second year will be taken to the large frame (50x50cm) direct shear test equipment and tested for direct shear. A comparison of shear strength of soil

  1. Retainer for laboratory animals

    NASA Technical Reports Server (NTRS)

    Lee, R. W.

    1979-01-01

    Bio-retainer holds laboratory animals in fixed position for research and clinical experiments. Retainer allows full access to animals and can be rapidly opened and closed to admit and release specimens.

  2. Reality of Retainers

    MedlinePlus

    ... The most common reason is to help your teeth stay set in their new positions after wearing braces . It's important to wear your retainer because as your body grows, your teeth do some shifting. The retainer helps to control ...

  3. Retainer for laboratory animals

    NASA Technical Reports Server (NTRS)

    Lee, R. W.

    1979-01-01

    Bio-retainer holds laboratory animals in fixed position for research and clinical experiments. Retainer allows full access to animals and can be rapidly opened and closed to admit and release specimens.

  4. Reality of Retainers

    MedlinePlus

    ... A Real Lifesaver Kids Talk About: Coaches The Reality of Retainers KidsHealth > For Kids > The Reality of Retainers Print A A A What's in ... minutes each day. You may also notice an increased saliva flow (more spit in your mouth) in ...

  5. Investigation of deformation of elements of three-dimensional reinforced concrete structures located in the soil, interacting with each other through rubber gaskets

    NASA Astrophysics Data System (ADS)

    Berezhnoi, D. V.; Balafendieva, I. S.; Sachenkov, A. A.; Sekaeva, L. R.

    2017-06-01

    In work the technique of calculation of elements of three-dimensional reinforced concrete substructures located in a soil, interacting with each other through rubber linings is realized. To describe the interaction of deformable structures with the ground, special “semi-infinite” finite elements are used. A technique has been implemented that allows one to describe the contact interaction of three-dimensional structures by means of a special contact finite element with specific properties. The obtained numerical results are compared with the experimental data, their good agreement is noted.

  6. Retained Digital Flexible Ureteroscopes

    PubMed Central

    Huynh, Melissa; Telfer, Siobhan; Pautler, Stephen; Denstedt, John

    2017-01-01

    Abstract This report documents two instances of retained flexible ureteroscopes at the time of ureteroscopy and laser lithotripsy in a healthy 37-year-old male and a 53-year-old male with a pelvic kidney. We describe maneuvers to remove the ureteroscope endoscopically in the first case, while the second case required conversion to open surgery for ureteroscope extrication. PMID:28265593

  7. Aesthetic Retainer cum Trainer.

    PubMed

    Tripathi, Tulika; Kalra, Shilpa; Rai, Priyank

    2017-01-01

    Tongue thrust habit is one of the contributing factors in the relapse of orthodontic treatment results. Compliance with removable habit breaking appliance is a major issue to the dental practitioners treating patients of any age group. Through this case we introduce a more aesthetic and comfortable option to the patients requiring habit control for tongue thrusting and retention of treatment results. Hence, this appliance acts as a retainer cum trainer in such patients.

  8. Aesthetic Retainer cum Trainer

    PubMed Central

    Kalra, Shilpa; Rai, Priyank

    2017-01-01

    Tongue thrust habit is one of the contributing factors in the relapse of orthodontic treatment results. Compliance with removable habit breaking appliance is a major issue to the dental practitioners treating patients of any age group. Through this case we introduce a more aesthetic and comfortable option to the patients requiring habit control for tongue thrusting and retention of treatment results. Hence, this appliance acts as a retainer cum trainer in such patients. PMID:28274080

  9. Reinforced microextraction of polycyclic aromatic hydrocarbons from polluted soil samples using an in-needle coated fiber with polypyrrole/graphene oxide nanocomposite.

    PubMed

    Behfar, Mina; Ghiasvand, Ali Reza; Yazdankhah, Fatemeh

    2017-07-01

    The surface of a stainless-steel wire was platinized using electrophoretic deposition method to create a high-surface-area with porous and cohesive substrate. The platinized fiber was coated by the polypyrrole/graphene oxide nanocomposite by electropolymerization and accommodated into a stainless-steel needle to fabricate an in-needle coated fiber. The developed setup was coupled to gas chromatography with flame ionization detection and applied to extract and determine polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene, and pyrene) in complicated solid matrices, along with reinforcement of the extraction by cooling the sorbent, using liquid carbon dioxide. To obtain the best extraction efficiency, the important experimental variables including extraction temperature and time, temperature of cooled sorbent, sampling flow rate, and desorption condition were studied. Under the optimal condition, limits of detection for five studied analytes were in the range of 0.2-0.8 pg/g. Linear dynamic ranges for the calibration curves were found to be in the range of 0.001-1000 ng/g. Relative standard deviations obtained for six replicated analyses of 1 ng/g of analytes were 4.9-13.5%. The reinforced in-needle coated fiber method was successfully applied for the analysis of polycyclic aromatic hydrocarbons in contaminated soil samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO THE CONCRETE SLAB. NOTE THE 1¾" MOUNTING BOLTS FOR THE STEEL PLATE BASE OF THE 5" GUN, SET IN THE GUN BLOCK. STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOPS OF THE RETAINING WALLS ARE ALSO VISIBLE. VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  11. Retained gas inventory comparison

    SciTech Connect

    BARTON, W.B.

    1999-05-18

    Gas volume data derived from four different analytical methods were collected and analyzed for comparison to volumes originally used in the technical basis for the Basis for Interim Operations (BIO). The original volumes came from Hodgson (1996) listed in the reference section of this document. Hodgson (1996) screened all 177 single and double-shell tanks for the presence of trapped gas in waste via two analytical methods: Surface Level Rise (SLR), and Barometric Pressure Effect (BPE). More recent gas volume projections have been calculated using different analytical techniques along with updates to the parameters used as input to the SLR and BPE models. Gas volumes derived from new analytical instruments include those as measured by the Void Fraction Instrument (VFI) and Retained Gas Sampler (RGS). The results of this comparison demonstrate that the original retained gas volumes of Hodgson (1996) used as a technical basis in developing the BIO were conservative, and were conservative from a safety analysis standpoint. These results represent only comparisons to the original reported volumes using the limited set of newly acquired data that is available.

  12. Prevention of retained surgical items.

    PubMed

    Feldman, David L

    2011-01-01

    Reduction in retained surgical items is an important part of any operating room patient-safety effort. Any item used in an operation can result in a retained surgical item, but sponges are the most frequent and the abdomen is the most common location. Retained sponges can cause significant morbidity, and the costs associated with both prevention and treatment of retained surgical items, including legal costs, can be considerable. This review will examine counting, teamwork, radiography, and new technology as methods used to prevent retained surgical items. Even though none of these techniques individually is likely to completely prevent retained surgical items, when used together the numbers can be reduced.

  13. Clubfoot: a cord retainer.

    PubMed

    Fahmy, W M; Fahmy, H W

    1989-01-01

    Using a cord to retain the surgically corrected clubfoot replaces the need for repeated plaster casts and prolonged orthotics. Cords of braided polyester or nylon suture material 0.5 mm in diameter (a pair or more) were stretched between the fifth metatarsal and the lower metaphysis of the fibula. The required strength of the cord was judged from the initial range of motion (ROM) of the ankle and subtalar joints, and a factor derived from the body weight. The mean follow-up in five patients was 26.8 months (range 18-33 months). The peroneal muscles recovered an average of 9 months (range 7-11 months). Our one failure was caused by inaccurate estimation of cord strength.

  14. Polyurethane retainers for ball bearings

    NASA Technical Reports Server (NTRS)

    Christy, R. I.

    1973-01-01

    Evaluation of a new ball bearing retainer material is reported. A special composite polyurethane foam ball retainer has been developed that has virtually zero wear, is chemically inert to hydrocarbon lubricants, and stores up to 60 times as much lubricant per unit volume as the most commonly used retainer material, cotton phenolic. This new retainer concept shows promise of years of ball bearing operation without reoiling, based on life testing in high vacuum.

  15. Soils

    Treesearch

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  16. Soil

    USDA-ARS?s Scientific Manuscript database

    Soil is a diverse natural material characterized by solid, liquid, and gas phases that impart unique chemical, physical, and biological properties. Soil provides many key functions, including supporting plant growth and providing environmental remediation. Monitoring key soil properties and processe...

  17. Computation of the seismic stability of earth retaining structures

    SciTech Connect

    1998-07-30

    The purpose of this CRADA project was to evaluate the seismic stability of block retaining wall systems. Retaining wall systems are used extensively in private and commercial developments. This study was designed to develop and demonstrate a computer modeling technology to be used to predict the seismic stability of any block wall system design. The nonlinear finite element computer programs developed at LLNL and employed in the Computational Earthquake Initiative were utilized in this small business CRADA to analyze the seismic stability of the block retaining walls. The unique capability of the LLNL programs to rigorously model frictional contact in a dynamic analysis problem were used in a computer simulation of the dynamic interaction the block wall/soil systems under seismic excitation. Another important application, and the focus of the proposal, was the use of block retaining walls in highway transportation systems to provide a vertical wall to hold back a mass of soil near highway bridges, and at on-ramps and off-ramps. Block retaining walls offered the potential of highway retaining wall construction which was both more flexible and more economical than existing poured-in-place and tilt-up highway retaining wall construction. However, block retaining wall technology was not embraced and utilized in the State of California as a result of seismic stability concerns expressed by Caltrans. Caltrans had an interest in utilizing block wall systems as soil retaining systems for major highway structures in California, but they stated to the block wall manufacturers and the manufacturer's engineering consultants that block retaining walls could not be employed until Caltrans was convinced of the earthquake stability of such systems.

  18. Conjugate Reinforcement.

    ERIC Educational Resources Information Center

    Lewis, Richard F.

    Conjugate reinforcement is a new attention measure which has emerged from experimental psychology. It can provide accurate measurement of a subject's attention to a stimulus. In conjugate reinforcement, the duration of the stimulus varies directly and immediately with the subject's rate of response. In this process, the subject must demonstrate…

  19. Advances in root reinforcement experiments

    NASA Astrophysics Data System (ADS)

    Giadrossich, Filippo; Schwarz, Massimiliano; Niedda, Marcello

    2013-04-01

    Root reinforcement is considered in many situations an important effect of vegetation for slope stability. In the past 20 years many studies analyzed root reinforcement in laboratory and field experiments, as well as through modeling frameworks. Nearby the important contribution of roots to shear strength, roots are recognized to impart stabilization also through lateral (parallel to slope) redistribution of forces under tension. Lateral root reinforcement under tensile solicitations (such as in the upper part of a shallow landslide) was documented and discussed by some studies. The most common method adopted to measure lateral root reinforcement are pullout tests where roots (single or as bundle) are pulled out from a soil matrix. These conditions are indeed representative for the case where roots within the mass of a landslide slip out from the upper stable part of the slope (such in a tension crack). However, there is also the situation where roots anchored at the upper stable part of the slope slip out from the sliding soil mass. In this last case it is difficult to quantify root reinforcement and no study discussed this mechanism so far. The main objective of this study is to quantify the contribution of roots considering the two presented cases of lateral root reinforcement discussed above - roots slipping out from stable soil profile or sliding soil matrix from anchored roots-, and discuss the implication of the results for slope stability modeling. We carried out a series of laboratory experiments for both roots pullout and soil sliding mechanisms using a tilting box with a bundle of 15 roots. Both Douglas (Pseudotsuga menziesii) roots and soil were collected from the study area in Sardinia (Italy), and reconstructed in laboratory, filling the root and soil layer by layer up to 0.4 meter thickness. The results show that the ratio between pullout force and force transferred to the root during soil sliding range from 0.5 to 1. This results indicate that

  20. Recruiting and retaining medical technologists.

    PubMed

    Barcus, S; Bernice, J; Evans, J; Labbe, P; Leedy, J A; Rabbitts, D G; Riedemann, G; Therrien, R; Thiessen, C

    1992-01-01

    Personnel recruitment and retention is one of the most challenging facets of management. Despite turnover rates, identifying and retaining good employees should be foremost on any managerial agenda. An effective employee recruiting/relations program enhances the overall productivity of an operation by addressing concerns at staff level, often considered the core of activity. In this issue, we asked our respondents: What methods do you use to recruit and retain medical technologists?

  1. 7 CFR 1767.25 - Retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Retained earnings. 1767.25 Section 1767.25....25 Retained earnings. The retained earnings accounts identified in this section shall be used by all RUS borrowers. Retained Earnings 433-439 Retained Earnings 433-439 ...

  2. Electrical transmission line diametrical retainer

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2004-12-14

    The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within down hole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to with stand the tension and compression of drill pipe during routine drilling cycles.

  3. Soils

    Treesearch

    John R. Jones; Norbert V. DeByle

    1985-01-01

    Edaphic and climatic characteristics of a site quite well define the quality of that site for plant growth. The importance of soil characteristics to the growth and well-being of aspen in the West is apparent from observations by many authors, from inferences resulting from work with other trees and agricultural crops, and from detailed study of aspen soils and site...

  4. Choice as a function of reinforcer "hold": from probability learning to concurrent reinforcement.

    PubMed

    Jensen, Greg; Neuringer, Allen

    2008-10-01

    Two procedures commonly used to study choice are concurrent reinforcement and probability learning. Under concurrent-reinforcement procedures, once a reinforcer is scheduled, it remains available indefinitely until collected. Therefore reinforcement becomes increasingly likely with passage of time or responses on other operanda. Under probability learning, reinforcer probabilities are constant and independent of passage of time or responses. Therefore a particular reinforcer is gained or not, on the basis of a single response, and potential reinforcers are not retained, as when betting at a roulette wheel. In the "real" world, continued availability of reinforcers often lies between these two extremes, with potential reinforcers being lost owing to competition, maturation, decay, and random scatter. The authors parametrically manipulated the likelihood of continued reinforcer availability, defined as hold, and examined the effects on pigeons' choices. Choices varied as power functions of obtained reinforcers under all values of hold. Stochastic models provided generally good descriptions of choice emissions with deviations from stochasticity systematically related to hold. Thus, a single set of principles accounted for choices across hold values that represent a wide range of real-world conditions.

  5. Screw-Retaining Allen Wrench

    NASA Technical Reports Server (NTRS)

    Granett, D.

    1985-01-01

    Steadying screws with fingers unnecessary. Crimp in uncompressed spring wire slightly protrudes from one facet of Allen wrench. Compressed spring retains Allen screw. Tool used with Allen-head screws in cramped spaces with little or no room for fingers to hold fastener while turned by wrench.

  6. Recruiting and Retaining Adult Students.

    ERIC Educational Resources Information Center

    Hadfield, Janice

    2003-01-01

    Adult learners, long the stepchildren of colleges and universities, have nearly become the norm, and they spend billions of dollars each year on education. This chapter takes a customer-oriented approach to recruiting and retaining adult students in higher education. (GCP)

  7. Program Evaluation: Accelerating Retained Students

    ERIC Educational Resources Information Center

    Juneau, Lisa

    2014-01-01

    The purpose of this program evaluation was to evaluate the first year of an acceleration program that allowed students who were retained a grade level for not performing on academic level in early elementary school an opportunity to rejoin their age appropriate class. The primary focus of the evaluation was to evaluate the effectiveness of an…

  8. Recruiting and Retaining Summer Staff.

    ERIC Educational Resources Information Center

    Crossen, Brian; Yerkes, Rita

    1998-01-01

    Recruiting of camp staff is challenged by economic and workplace restructuring, including business downsizing, part-time and temporary employment patterns, and generational attitude changes. Strategies for hiring and retaining staff include knowing what college-age workers want, marketing benefits, adopting new business strategies, and empowering…

  9. Program Evaluation: Accelerating Retained Students

    ERIC Educational Resources Information Center

    Juneau, Lisa

    2014-01-01

    The purpose of this program evaluation was to evaluate the first year of an acceleration program that allowed students who were retained a grade level for not performing on academic level in early elementary school an opportunity to rejoin their age appropriate class. The primary focus of the evaluation was to evaluate the effectiveness of an…

  10. Seismic behavior of geogrid reinforced slag wall

    SciTech Connect

    Edincliler, Ayse; Baykal, Gokhan; Saygili, Altug

    2008-07-08

    Flexible retaining structures are known with their high performance under earthquake loads. In geogrid reinforced walls the performance of the fill material and the interface of the fill and geogrid controls the performance. Geosynthetic reinforced walls in seismic regions must be safe against not only static forces but also seismic forces. The objective of this study is to determine the behavior of a geogrid reinforced slag wall during earthquake by using shaking table experiments. This study is composed of three stages. In the first stage the physical properties of the material to be used were determined. In the second part, a case history involving the use of slag from steel industry in the construction of geogrid reinforced wall is presented. In the third stage, the results of shaking table tests conducted using model geogrid wall with slag are given. From the results, it is seen that slag can be used as fill material for geogrid reinforced walls subjected to earthquake loads.

  11. Tropical soils in Mato Grosso, Brazil, retain high phosphorus (P) binding capacity after 30 years of intensive fertilization and will remain a P sink for another 50-160 years.

    NASA Astrophysics Data System (ADS)

    Porder, S.; Roy, E.; Willig, E.; Martinelli, L. A.; Pegorini, L.; Richards, P.; Spera, S. A.; Vazquez, F. F.

    2016-12-01

    Intensification of tropical agriculture is one way to meet increasing global food demand, but tropical soils often require more phosphorus (P) fertilizer than those in the world's traditional breadbaskets. Recent studies from Europe suggest that P fertilizer additions will eventually saturate soil P binding capacity, and can build a soil P bank upon which future crop production can draw. We tested this hypothesis in Mato Grosso, Brazil, where highly mechanized agriculture produces 9% of the world's soy harvest on soils with high P binding capacity. In this region, P fertilizer inputs typically exceed harvests by 10kg P/ha, and our expectation was that total P and available P would increase, and P binding capacity would decrease, with time in cultivation. To test this hypothesis, we measured P availability, binding, and accumulation on 31 fields ranging from 0-31 years in intensive production. We also estimated the number of years in production that would be required to saturate the soils with P, since after that time P additions could be reduced to equal harvest P removal. As expected, our data show increasing P availability, and decreasing P binding capacity, over time. A multiple regression including only soil [SiO2] (a proxy for both mineralogy and texture) and years in production explained 87, 63 and 91% of the observed variation in total P, Bray-extractable P, and P sorption capacity, respectively. However, the effect of [SiO2], and thus texture and mineralogy, was 1.7, 1.2, and 4.9 times more important in predicting our dependent variables than was years in production. Despite fertilizer inputs in excess of harvest removals, the reduction in P binding capacity is slow, and we estimate it will take between 50-160 years for fertilizer inputs to saturate the P binding capacity of these soils. These results suggest that the P tax imposed by high P binding soils in the tropics will impose substantial material costs to tropical farmers in the coming decades, and

  12. Inlay-retained zirconia fixed dental prosthesis: clinical and laboratory procedures.

    PubMed

    Monaco, Carlo; Cardelli, Paolo; Bolognesi, Michele; Scotti, Roberto; Ozcan, Mutlu

    2012-01-01

    Many treatment options are currently available for single tooth replacement, such as metal-ceramic, all-ceramic, direct or indirect fiber-reinforced composite fixed dental prostheses (FDPs) or implants. Inlay-retained FDPs could be indicated especially when adjacent teeth have preexisting restorations and where implant placement is not possible or not indicated. In such cases, indication of both metal-ceramic and fiber-reinforced composite FDPs has certain disadvantages. This paper describes the use of all-ceramic inlay-retained FDPs with zirconia frameworks, veneered with a press-on technique. The retainer margins were made of pressed ceramic to make adhesive luting possible. In deep cavities, a full contour press-on ceramic all around the retainers increased the available surface area for the adhesive approach.

  13. Inlay-retained zirconia fixed dental prostheses: modified designs for a completely adhesive approach.

    PubMed

    Monaco, Carlo; Cardelli, Paolo; Ozcan, Mutlu

    2011-01-01

    Currently, there are many options for single-tooth replacement: metal-ceramic, all-ceramic, direct or indirect fibre-reinforced composite fixed dental prostheses (FDPs) or implants. Inlay-retained FDPs may especially be indicated when adjacent teeth have been previously restored and when implant placement is not possible or not indicated. In such cases, both metal-ceramic and fibre-reinforced composite FDPs have certain disadvantages. In this paper, we describe the use of all-ceramic inlay-retained FDPs with zirconia frameworks, veneered using a press-on technique.

  14. Recycling of Reinforced Plastics

    NASA Astrophysics Data System (ADS)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  15. Modified spiral wound retaining ring

    NASA Technical Reports Server (NTRS)

    Lawson, A. G. (Inventor)

    1980-01-01

    A spiral wound retaining ring with angled ends is described. The ring is crimped at the same angle as the ring ends to maintain a constant thickness dimension. The angling of the ends of the ring and crimp allow the ends to be positioned closer together while maintaining enough clearance to enable insertion and removal of the ring. By reducing the separation distance between the ends a stronger ring results since the double layer area of the ring is maximized.

  16. Seismic Structural Considerations for the Stern and Base of Retaining Walls Subjected to Earthquake Ground Motions

    DTIC Science & Technology

    2005-05-01

    Unit 4402JC, entitled “Soil-Structure Interaction for Seismic Evaluation of Earth - Retaining Lock and Cantilever Walls ” for which Dr. Robert M. Ebeling...Introduction Figure 1.3 Earthquake-induced flexural yielding of stem wall and permanent displacement The seismic evaluation of earth retaining wall ...effects depends on the reserve capacity available in the design for static earth pressures. This aspect is investigated for older retaining wall

  17. Seismic Structural Considerations for the Stem and Base of Retaining Walls Subjected to Earthquake Ground Motions

    DTIC Science & Technology

    2005-05-01

    Structure Interaction for Seismic Evaluation of Earth - Retaining Lock and Cantilever Walls " for which Dr. Robert M. Ebeling, Engineering and Informatic...yielding of stem wall and permanent displacement The seismic evaluation of earth retaining wall structures is more complex due to soil-structure...for static earth pressures. This aspect is investigated for older retaining wall systems by examining the margin of safety inherent in the old working 4

  18. Intraluminal Bowel Erosion: A Rare Complication of Retained Gallstones after Cholecystectomy

    PubMed Central

    McQuay, Nathaniel

    2016-01-01

    Laparoscopic cholecystectomy for acute cholecystitis and cholelithiasis is one of the most common operations performed in the United States. Inadvertent perforation and spillage of gallbladder contents are not uncommon. The potential impact of subsequent retained gallstones is understated. We present the case of an intraperitoneal gallstone retained from a previous cholecystectomy eroding into the bowel and leading to intraluminal mechanical bowel obstruction requiring operative intervention. This case illustrates the potential risks of retained gallstones and reinforces the need to diligently collect any dropped stones at the time of initial operation. PMID:27703833

  19. Sapphire reinforced alumina matrix composites

    NASA Technical Reports Server (NTRS)

    Jaskowiak, Martha H.; Setlock, John A.

    1994-01-01

    Unidirectionally reinforced A1203 matrix composites have been fabricated by hot pressing. Approximately 30 volume % of either coated or uncoated sapphire fiber was used as reinforcement. Unstabilized ZrO2 was applied as the fiber coating. Composite mechanical behavior was analyzed both after fabrication and after additional heat treatment. The results of composite tensile tests were correlated with fiber-matrix interfacial shear strengths determined from fiber push-out tests. Substantially higher strength and greater fiber pull-out were observed for the coated fiber composites for all processing conditions studied. The coated fiber composites retained up to 95% and 87% of their as-fabricated strength when heat treated at 14000C for 8 or 24 hours, respectively. Electron microscopy analysis of the fracture surfaces revealed extensive fiber pull-out both before and after heat treatment.

  20. Reinforced structural plastics

    NASA Technical Reports Server (NTRS)

    Lubowitz, H. R.; Kendrick, W. P.; Jones, J. F.; Thorpe, R. S.; Burns, E. A. (Inventor)

    1972-01-01

    Reinforced polyimide structures are described. Reinforcing materials are impregnated with a suspension of polyimide prepolymer and bonded together by heat and pressure to form a cured, hard-reinforced, polyimide structure.

  1. Residual Earth Pressure on a Retaining Wall with Sand Backfill Subjected to Forced Cyclic Lateral Displacements

    NASA Astrophysics Data System (ADS)

    Hirakawa, Daiki; Nojiri, Minehiro; Aizawa, Hiroyuki; Tatsuoka, Fumio; Sumiyoshi, Takashi; Uchimura, Taro

    A pair of about 11 m-high soil retaining walls of an U-shaped underground reinforced concrete (RC) structure in Tokyo exhibited a large residual inward (i.e., toward the active side) displacement with potential structural damage, which became 18 cm between the tops of the two walls about three years after its completion. Noticeable settlements of the backfill were observed behind the walls. A series of small-scale model tests was performed in the laboratory to understand this field behaviour. The results from in-situ investigation and model tests showed that this wall behaviour can be attributed to a gradual increase in the residual lateral earth pressure, resulting from cyclic lateral displacements of the walls caused by a small number of relatively large seasonal thermal cyclic displacement of the RC wall facing and bottom slab of the structure, not by a great number of relatively small daily displacement. Three factors for the mechanism of this wall behaviour (i.e., ratcheting, cyclic hardening and cyclic loading-induced residual deformation of the backfill) were identified and analyzed based the model test results. The settlement in the backfill observed in the model tests is consistent with the field behaviour.

  2. Reinforced Carbon Nanotubes.

    DOEpatents

    Ren, Zhifen; Wen, Jian Guo; Lao, Jing Y.; Li, Wenzhi

    2005-06-28

    The present invention relates generally to reinforced carbon nanotubes, and more particularly to reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  3. Effect of tree roots on a shear zone: modeling reinforced shear stress.

    Treesearch

    Kazutoki Abe; Robert R. Ziemer

    1991-01-01

    Tree roots provide important soil reinforcement that impoves the stability of hillslopes. After trees are cut and roots begin to decay, the frequency of slope failures can increase. To more fully understand the mechanics of how tree roots reinforce soil, fine sandy soil containing pine roots was placed in a large shear box in horizontal layers and sheared across a...

  4. Effortless way of bonding a lingual retainer.

    PubMed

    Pai, Vikram; Pai, Ramya; Revenkar, Ameet; Jasoria, Gaurav

    2013-01-01

    Post orthodontic treatment, retention is one of the most important step for prevention of relapse. Over the years many direct and indirect techniques for placing a bonded lingual retainer have been practiced clinically. Present clinical practice demands a much convenient and effortless technique for bonding a lingual retainer. This article describes a simplified technique of bonding a lingual retainer.

  5. 47 CFR 32.4550 - Retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Retained earnings. 32.4550 Section 32.4550... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.4550 Retained earnings. (a) This account shall include the undistributed balance of retained earnings derived from the...

  6. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Retained water. 441.10 Section 441.10... STANDARDS: RAW PRODUCTS § 441.10 Retained water. (a) Raw livestock and poultry carcasses and parts will not be permitted to retain water resulting from post-evisceration processing unless the...

  7. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  8. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  9. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  10. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  11. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  12. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  13. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  14. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  15. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  16. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  17. Reducing Behavior through Reinforcement.

    ERIC Educational Resources Information Center

    Deitz, Diane E. D.; Repp, Alan C.

    1983-01-01

    The use of reinforcement to reduce inappropriate behaviors of mentally retarded and emotionally disturbed students may involve the following procedures: differential reinforcement of low rates of responding (DRL), the differential reinforcement of response omission (DRO), and the differential reinforcement of incompatible (DRI) or alternative…

  18. The Reinforcement Hierarchy

    ERIC Educational Resources Information Center

    Forness, Steven R.

    1973-01-01

    Reinforcement hierarchy implies movement along a continuum from top to bottom, from primitive levels of reinforcement to more sophisticated levels. Unless it is immediately obvious that a child cannot function without the use of lower-order reinforcers, we should approach him as though he responds to topmost reinforcers until he demonstrates…

  19. An Innovative Approach to Retention: Thermoplastic Retainer.

    PubMed

    Ozeer, K A Adam; David, Sumitha A; Mohamed, Umar; Sunil, P C; Paul, Sam; Paul, Parson

    2017-07-01

    The aim of this study was to design and introduce a retainer that overcomes the common shortcomings seen in other retainers. Hard thermoplastic sheet of 0.5 mm thickness is vacuum or pressure-molded onto the patient cast. Lingual portion of the retainer is trimmed according to the contours of the anterior teeth. Contact points between the maxillary and mandibular anterior teeth are marked on the retainer and reduced. Punch cut holes are placed on the retainer for the exit of flash and air bubbles while fixation. The retainer is bonded onto the lingual surface of the anterior teeth using composite. A 1-month review of the retainer showed no patient discomfort, occlusal interference, or bond failure. The aim of the article was found to have been achieved. Initial evaluation has shown positive findings. Long-term clinical findings will determine the overall success of this new retainer. As compared with other retainers, thermoplastic retainer has shown reduced tendency to debond from occlusal forces, decreased patient discomfort, and occlusal interference.

  20. Early Loaded Single Implant Reinforced Mandibular Overdenture

    PubMed Central

    Chowdhary, R.

    2016-01-01

    Rehabilitating atrophied mandible with two-implant supported denture is a common treatment modality for implant retained removable overdenture in mandible. This paper aims to design a treatment modality where single implant reinforced overdenture is fabricated for a severely atrophied mandibular ridge with early loading protocol. Results of studies have shown that a single implant mandibular overdenture significantly increases the satisfaction and quality of life of patients with edentulism. Midline fracture of the prosthesis is the most common complication related to single implant and two-implant retained mandibular overdentures. To manage such complication, a thin metal mesh is used to reinforce the overdenture and also to make the prostheses lighter and cost effective as compared to conventional cast metal framework. PMID:27403350

  1. Federal Aviation Administration retained savings program proposal

    SciTech Connect

    Hostick, D.J.; Larson, L.L.; Hostick, C.J.

    1998-03-01

    Federal legislation allows federal agencies to retain up to 50% of the savings associated with implementing energy efficiency and water conservation measures and practices. Given budget pressures to reduce expenditures, the use of retained savings to fund additional projects represents a source of funds outside of the traditional budget cycle. The Southwest Region Federal Aviation Administration (FAA) has tasked Pacific Northwest National Laboratory (PNNL) to develop a model retained savings program for Southwest Region FAA use and as a prototype for consideration by the FAA. PNNL recommends the following steps be taken in developing a Southwest Region FAA retained savings program: Establish a retained savings mechanism. Determine the level at which the retained savings should be consolidated into a fund. The preliminary recommendation is to establish a revolving efficiency loan fund at the regional level. Such a mechanism allows some consolidation of savings to fund larger projects, while maintaining a sense of facility ownership in that the funds will remain within the region.

  2. Reinforcement of inhibition

    PubMed Central

    Anger, Douglas

    1983-01-01

    A differential-reinforcement-of-other-behavior (DRO) schedule with trials and delayed reinforcement was investigated. Periodically a wheel was briefly available to rats, followed six seconds later by brief availability of a bar. Variable-ratio food reinforcement of wheel turns was adjusted to give 95% turns. After variable-ratio-five reinforcement of bar presses produced 100% pressing, then separate ratio schedules were used for presses following turns (turn presses) and presses following nonturns (nonturn presses). Increasing nonturn-press reinforcements decreased turns, even though total reinforcements increased. Reversal by decreasing nonturn-press reinforcements raised turns, though with hysteresis. Thus food reinforcement increased nonturns even though delayed six to ten seconds after nonturns, a delay that greatly reduces response reinforcement. Those and other results indicate that the turn decrease was not due to reinforcement of competing responses. Evidence against other alternatives, and the reduction of responding by increased reinforcement, indicate that the term inhibition is appropriate for the phenomenon reinforced. Response-specific inhibition appears appropriate for this particular kind, since its effects are more specific to particular responses than Pavlovian conditioned-inhibition. Response-specific inhibition seems best considered a behavioral output comparable to responses (e.g., both reinforcible) but with important properties different from responses (e.g., different reinforcement-delay gradients). PMID:16812315

  3. A new type of clear orthodontic retainer incorporating multi-layer hybrid materials

    PubMed Central

    Ahn, Hyo-Won; Kim, Kyung A

    2015-01-01

    Clear thermoplastic retainers have been widely used in daily orthodontics; however, they have inherent limitations associated with thermoplastic polymer materials such as dimensional instability, low strength, and poor wear resistance. To solve these problems, we developed a new type of clear orthodontic retainer that incorporates multi-layer hybrid materials. It consists of three layers; an outer polyethylenterephthalate glycol modified (PETG) hard-type polymer, a middle thermoplastic polyurethane (TPU) soft-type polymer, and an inner reinforced resin core. The resin core improves wear resistance and mechanical strength, which prevent unwanted distortion of the bucco-palatal wall of the retainer. The TPU layer absorbs impact and the PETG layer has good formability, optical qualities, fatigue resistance, and dimensional stability, which contributes to increased support from the mandibular dentition, and helps maintain the archform. This new type of vacuum-formed retainer showed improved mechanical strength and rate of water absorption. PMID:26445722

  4. Reliability Coupled Sensitivity Based Design Approach for Gravity Retaining Walls

    NASA Astrophysics Data System (ADS)

    Guha Ray, A.; Baidya, D. K.

    2012-09-01

    Sensitivity analysis involving different random variables and different potential failure modes of a gravity retaining wall focuses on the fact that high sensitivity of a particular variable on a particular mode of failure does not necessarily imply a remarkable contribution to the overall failure probability. The present paper aims at identifying a probabilistic risk factor ( R f ) for each random variable based on the combined effects of failure probability ( P f ) of each mode of failure of a gravity retaining wall and sensitivity of each of the random variables on these failure modes. P f is calculated by Monte Carlo simulation and sensitivity analysis of each random variable is carried out by F-test analysis. The structure, redesigned by modifying the original random variables with the risk factors, is safe against all the variations of random variables. It is observed that R f for friction angle of backfill soil ( φ 1 ) increases and cohesion of foundation soil ( c 2 ) decreases with an increase of variation of φ 1 , while R f for unit weights ( γ 1 and γ 2 ) for both soil and friction angle of foundation soil ( φ 2 ) remains almost constant for variation of soil properties. The results compared well with some of the existing deterministic and probabilistic methods and found to be cost-effective. It is seen that if variation of φ 1 remains within 5 %, significant reduction in cross-sectional area can be achieved. But if the variation is more than 7-8 %, the structure needs to be modified. Finally design guidelines for different wall dimensions, based on the present approach, are proposed.

  5. Modeling of geosynthetic reinforced capping systems

    SciTech Connect

    Viswanadham, B.V.S.; Koenig, D.; Jessberger, H.L.

    1997-12-31

    The investigation deals with the influence of a geosynthetic reinforcement on the deformation behavior and sealing efficiency of the reinforced mineral sealing layer at the onset of non-uniform settlements. The research program is mainly concentrated in studying the influence of reinforcement inclusion in restraining cracks and crack propagation due to soil-geosynthetic bond efficiency. Centrifuge model tests are conducted in the 500 gt capacity balanced beam Bochum geotechnical Centrifuge (Z1) simulating a differential deformation of a mineral sealing layer of a landfill with the help of trap-door arrangement. By comparing the performance of the deformed mineral sealing layer with and without geogrid, the reinforcement ability of the geogrid in controlling the crack propagation and permeability of the mineral swing layer is evaluated.

  6. Food reinforcement during infancy

    PubMed Central

    Kong, Kai Ling

    2017-01-01

    The motivation to eat, as operationalized by measuring how hard someone will work for food, is cross-sectionally and prospectively related to obesity. Persons high in food reinforcement consume more calories, and energy intake mediates the relationship between food reinforcement and obesity. Research has shown avid sucking for milk in early infancy predicts later adiposity, and the relationship between food reinforcement and excess body weight has been observed in infants as young as 9 months of age. New methodological developments in studying food reinforcement in infants and young children provide the first opportunity to study the origin of food reinforcement. This review seeks to provide background on the measurement of food reinforcement, and to present, for the first time, prenatal and postnatal predictors of infant food reinforcement. Lastly, potential mechanisms for an increasing trajectory of food reinforcement throughout development are proposed. PMID:27373207

  7. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the time in chiller water, the water temperature, and agitation. The protocol should consider air... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Retained water. 441.10 Section 441.10... STANDARDS: RAW PRODUCTS § 441.10 Retained water. (a) Raw livestock and poultry carcasses and parts will...

  8. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the time in chiller water, the water temperature, and agitation. The protocol should consider air... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Retained water. 441.10 Section 441.10... STANDARDS: RAW PRODUCTS § 441.10 Retained water. (a) Raw livestock and poultry carcasses and parts will...

  9. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the time in chiller water, the water temperature, and agitation. The protocol should consider air... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Retained water. 441.10 Section 441.10... STANDARDS: RAW PRODUCTS § 441.10 Retained water. (a) Raw livestock and poultry carcasses and parts will...

  10. The Seismic Design of Waterfront Retaining Structures

    DTIC Science & Technology

    1992-11-01

    160 6.3.2 Analysis of Earthquake Induced Displacements for a Wall Retaining Dry Backfill...164 6.3.4 Analysis of Earthquake Induced Displacements for a Wall Retaining Submerged Backfill - No Excess Pore Water Pressures...Distribution of horizontal stresses corresponding to APAE . ... C20 C.6 Seismic design problem for a continuous anchor blast ...... .. C24 C.7

  11. 12 CFR 1805.504 - Retained earnings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS PROGRAM Matching Funds Requirements § 1805.504 Retained earnings. (a) An Applicant may use its retained earnings to match a request for a financial assistance...

  12. 12 CFR 1805.504 - Retained earnings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS PROGRAM Matching Funds Requirements § 1805.504 Retained earnings. (a) An Applicant may use its retained earnings to match a request for a financial assistance...

  13. 12 CFR 1805.504 - Retained earnings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS PROGRAM Matching Funds Requirements § 1805.504 Retained earnings. (a) An Applicant may use its retained earnings to match a request for a financial assistance...

  14. 45 CFR 1611.9 - Retainer agreements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Retainer agreements. 1611.9 Section 1611.9 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION FINANCIAL ELIGIBILITY § 1611.9 Retainer agreements. (a) When a recipient provides extended service to a client, the...

  15. 45 CFR 1611.9 - Retainer agreements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Retainer agreements. 1611.9 Section 1611.9 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION FINANCIAL ELIGIBILITY § 1611.9 Retainer agreements. (a) When a recipient provides extended service to a client, the...

  16. 45 CFR 1611.9 - Retainer agreements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Retainer agreements. 1611.9 Section 1611.9 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION FINANCIAL ELIGIBILITY § 1611.9 Retainer agreements. (a) When a recipient provides extended service to a client, the...

  17. Stabilising springs for fixed lingual retainer.

    PubMed

    Karthikeyan, M K; Ramachandraprabhakar; Saravanan, R; Rajvikram, N; Kuppuchamy

    2013-11-01

    Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove.

  18. Networking: A Method of Retaining Nursing Staff.

    ERIC Educational Resources Information Center

    Anderson, Rhonda; And Others

    1983-01-01

    Discusses the problem of turnover among nurses and proposes the use of networking as a means of retaining nursing staff. The plan relies on aspects of the nursing process--assessment, planning, implementation, and evaluation--to retain quality nursing staff. (JOW)

  19. Conservative Approach for Restoring Posterior Missing Tooth with Fiber Reinforcement Materials: Four Clinical Reports

    PubMed Central

    Karaarslan, Emine Sirin; Ertas, Ertan; Ozsevik, Semih; Usumez, Aslihan

    2011-01-01

    Adhesively luted, fiber-reinforced, composite-inlay, retained fixed-partial dentures can be a clinical alternative for the replacement of missing posterior teeth in selective situations. This type of restoration allows for satisfactory esthetics and reduced tooth preparation compared to a conventional, fixed-partial denture. This clinical report describes the use of a fiber-reinforced, composite-inlay, retained fixed-partial denture as a conservative alternative for the replacement of missing posterior teeth. PMID:21912503

  20. The effect of construction stage on the development of retaining wall

    NASA Astrophysics Data System (ADS)

    Ghazaly, Zuhayr Md; Rahim, Mustaqqim Abdul; Hiung, Voo Kien; Isa, Nur Fitriah; Sofri, Liyana Ahmad

    2017-04-01

    With the growing of population and density in metropolitan areas, especially for the narrow space areas, high rise buildings are the best choice to fulfil the demands for the lacking spaces for development. Hence, it seems deep excavation is necessary to construct underground spaces. Control of soil deformation is crucial for deep excavation in congested urban area to minimize its effect on adjacent structures. During excavation of the soil, retaining walls are required to retain the soil behind it. Therefore, an appropriate method or modelling is required to determine the movement of retaining wall due to lateral earth pressure acts behind it. Finite Element Method (FEM) utilizing computer program PLAXIS, was used to estimate the wall and ground deformation at each stage of excavation.

  1. Fiber reinforced engineering plastics

    Treesearch

    Daniel F. Caulfield; Rodney E. Jacobson; Karl D. Sears; John H. Underwood

    2001-01-01

    Although natural fiber reinforced commodity thermoplastics have a wide range of nonstructural applications in the automotive and decking industries, there have been few reports of cellulosic fiber-reinforced engineering thermoplastics. The commonly held belief has been that the only thermoplastics amenable to natural-fibre reinforcement are limited to low-melting (...

  2. Variable Resolution Reinforcement Learning.

    DTIC Science & Technology

    1995-04-01

    Can reinforcement learning ever become a practical method for real control problems? This paper begins by reviewing three reinforcement learning algorithms... reinforcement learning . In addition to exploring state space, and developing a control policy to achieve a task, partigame also learns a kd-tree partitioning of

  3. Partial Planning Reinforcement Learning

    DTIC Science & Technology

    2012-08-31

    This project explored several problems in the areas of reinforcement learning , probabilistic planning, and transfer learning. In particular, it...studied Bayesian Optimization for model-based and model-free reinforcement learning , transfer in the context of model-free reinforcement learning based on

  4. Reinforcement of Learning

    ERIC Educational Resources Information Center

    Jones, Peter

    1977-01-01

    A company trainer shows some ways of scheduling reinforcement of learning for trainees: continuous reinforcement, fixed ratio, variable ratio, fixed interval, and variable interval. As there are problems with all methods, he suggests trying combinations of various types of reinforcement. (MF)

  5. Single-step reinforced microextraction of polycyclic aromatic hydrocarbons from soil samples using an inside needle capillary adsorption trap with electropolymerized aniline/multi-walled carbon nanotube sorbent.

    PubMed

    Ghiasvand, Ali Reza; Yazdankhah, Fatemeh

    2017-03-03

    A polyaniline/multi-wall carbon nanotubes (PANI/MWCNT) composite was electrodeposited on the interior surface of a platinized stainless steel capillary needle and used to prepare an inside needle capillary adsorption trap (INCAT) device. The platinization expanded the interior adsorbing surface of the needle and made it more porous and cohesive for nanocomposite film. The nanocomposite was characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The fabricated INCAT was fixed into a cooling capsule to fabricate a cooling-assisted INCAT (CA-INCAT) system. The CA-INCAT device was used to extract polycyclic aromatic hydrocarbons (PAHs) from solid samples followed by gas chromatography-flame ionization detection (GC-FID) determination. To obtain the best extraction efficiency, the important experimental variables were studied and optimized. Under the optimal conditions, the limits of detection (LODs) for the studied PAHs were in the range of 0.002-0.02ngg(-1). Linear dynamic ranges (LDRs) for the calibration curves were found to be 0.1-30,000ngg(-1). Relative standard deviations (RSDs%) for six replicated analysis of 1ngg(-1) PAHs were obtained 7.7-11%. The CA-INCAT-GC-FID method was successfully applied for the extraction and determination of PAHs in contaminated soil samples. The results were in agreement with those obtained by a validated ultrasound-assisted solvent extraction (UA-SE) method.

  6. Reinforcement effects of fiberglass on telescopic dentures using a three-dimensional finite element analysis and fracture test.

    PubMed

    Nagata, Kohji; Takahashi, Hidekazu; Ona, Masahiro; Hosomi, Hiroyasu; Wakabayashi, Noriyuki; Igarashi, Yoshimasa

    2009-09-01

    The purpose of this study was to evaluate the reinforcing effect of fiberglass on composite resin retainers of the telescopic dentures. A finite element method was used to assess the effect of the abutment height and the embedment of the fiberglass on the stress distributions of the retainers. The experimental retainers of Poly(methylmethacrylate), composite resin (CR) and the fiber-reinforced composite resin (FRC) were used in the fracture test. The fracture load of the FRC retainers were significantly greater than those of the other retainers. The embedment of the fiberglass reduced the stress at the upper surface of the CR retainers. The fracture origin in the CR retainers was seen on the upper surface, while that of the FRC was at the cervical region near the abutment. These results suggest that the change in the fracture pass by the fiberglass increased the fracture resistance of the CR retainer.

  7. Inadvertent tooth movement with fixed lingual retainers.

    PubMed

    Shaughnessy, Timothy G; Proffit, William R; Samara, Said A

    2016-02-01

    Fixed retainers are effective in maintaining the alignment of the anterior teeth more than 90% of the time, but they can produce inadvertent tooth movement that in the most severe instances requires orthodontic retreatment managed with a periodontist. This is different from relapse into crowding when a fixed retainer is lost. These problems arise when the retainer breaks but remains bonded to some or all teeth, or when an intact retainer is distorted by function or was not passive when bonded. In both instances, torque of the affected teeth is the predominant outcome. A fixed retainer made with dead soft wire is the least likely to create torque problems but is the most likely to break. Highly flexible twist wires bonded to all the teeth appear to be the most likely to produce inadvertent tooth movement, but this also can occur with stiffer wires bonded only to the canines. Orthodontists, general dentists, and patients should be aware of possible problems with fixed retainers, especially those with all teeth bonded, because the patient might not notice partial debonding. Regular observations of patients wearing fixed retainers by orthodontists in the short term and family dentists in the long term are needed.

  8. An in situ Earth reinforcement lateral support system

    NASA Astrophysics Data System (ADS)

    Shen, C. K.; Herrmann, L. R.; Romstad, K. M.; Bang, S.; Kim, Y. S.; Denatale, J. S.

    1981-03-01

    An in situ reinforcement lateral support system is composed of an array of reinforcing members that are grouted into the soil mass, a wire-mesh reinforced shotcrete panel facing, and rows of re-bars which form horizontal wales at each reinforcement level. An analytical procedure for evaluating the stability of the system is formulated and the stability analysis is verified by means of a centrifuge model. Studies are presented of the application of this system. The major factors controlling the stability and ground movement of the system were found to be the construction sequence, the soil type, the length, size, and spacing of the reinforcing members, and their orientation with respect to the horizontal ground surface. The system seems to be economical in construction time and cost, and is a viable alternative to more conventional methods for providing temporary support in deep excavation.

  9. Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

    PubMed Central

    Wu, Yankai; Li, Yanbin; Niu, Bin

    2014-01-01

    Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment. PMID:24982951

  10. Assessment of the mechanical properties of sisal fiber-reinforced silty clay using triaxial shear tests.

    PubMed

    Wu, Yankai; Li, Yanbin; Niu, Bin

    2014-01-01

    Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

  11. HYBRID-SANDWICHED REINFORCEMENT WITH GEOSYNTHETICS

    NASA Astrophysics Data System (ADS)

    Yasuhara, Kazuya; Yamazaki, Shinji; Sakakibara, Tsutomu

    Advantageous aspects of sandwich-type reinforced earth structures combined with geosynthetics and sand mat are highlighted in this paper. Those aspects were elucidated by two kinds of laboratory tests : (1) large consolidation tests for improvement of hydraulic conductivity and (2) model footing tests on improvement of bearing capacity and deformation characteristics for reinforced earth structures, including both vertical permeability and horizontal transmissibility characteristics of geosynthetics results from both laboratory tests indicated the following: i) Hydraulic conductivity of geosynthetics used for this type of earth reinforcement can be maintained for a long period. Such conductivity sometimes disappears, particularly because of clogging when geosynthetics are adopted in embankment construction using fine-grained soils. This fact indicates that the sand mats which are laid above and beneath geosynthetics play a salient role in preventing clogging of geosynthetics that occurs by intrusion of fines from cohesive soils. ii) Sandwich-type reinforcement combined with geosynthetics and sand mats increases stability and decreases deformation of earth structures. In particular, the sandwich structure is effective for providing toughness, which has remained an important issue for reducing infrastructural maintenance and costs. In the later part of the paper, conventionally available stability analysis was carried out to propose the design procedure for reinforced earth structures and at the same time numerical analysis was also conducted to ensure the applicability of the hybrid-sandwiched earth reinforcement newly proposed in the current paper. Finally, based on the horizontal placement by means of HBS described in the current paper, the vertical drain procedure using the sandwich structures for accelerating consolidation and increasing stability of soft soils is also suggested for the future research and investigation.

  12. Attracting and retaining nurses in HIV care.

    PubMed

    Puplampu, Gideon L; Olson, Karin; Ogilvie, Linda; Mayan, Maria

    2014-01-01

    Attracting and retaining nurses in HIV care is essential to treatment success, preventing the spread of HIV, slowing its progression, and improving the quality of life of people living with HIV. Despite the wealth of studies examining HIV care, few have focused on the factors that influenced nurses' choices to specialize in HIV care. We examined the factors that attracted and retained eight nurses currently working in HIV care in two large Canadian cities. Participants were primarily women between the ages of 20 and 60 years. Interviews were conducted between November 2010 and September 2011 using interpretive description, a qualitative design. Factors that influenced participants to focus their careers in HIV care included both attracting factors and retaining factors. Although more research is needed, this exploration of attracting and retaining factors may motivate others to specialize in HIV nursing, and thus help to promote adequate support for individuals suffering from the disease.

  13. VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOP OF THE RETAINING WALL. VIEW FACING NORTHEAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  14. Thermally Activated Retainers For Insertion In Gaps

    NASA Technical Reports Server (NTRS)

    Grimaldi, Margaret E.; Hartz, Leslie S.

    1992-01-01

    Mechanical retainers of new type for use with gap filler easy to install and to attach themselves securely. Concept based on shape-memory properties of metal alloy Nitinol, alloy of nickel and titanium. Retainers conceived for use with Space Shuttle insulating tiles but used on other assemblies of blocks or tiles configured similarly. Tabs bent outward made flush by cooling below memory transition temperature. After insertion in gap and reheating, tabs spring outward.

  15. Stabilising Springs for Fixed Lingual Retainer

    PubMed Central

    Karthikeyan, M.K.; Ramachandraprabhakar; Saravanan, R.; Rajvikram, N.; Kuppuchamy

    2013-01-01

    Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove. PMID:24392431

  16. Thermally Activated Retainers For Insertion In Gaps

    NASA Technical Reports Server (NTRS)

    Grimaldi, Margaret E.; Hartz, Leslie S.

    1992-01-01

    Mechanical retainers of new type for use with gap filler easy to install and to attach themselves securely. Concept based on shape-memory properties of metal alloy Nitinol, alloy of nickel and titanium. Retainers conceived for use with Space Shuttle insulating tiles but used on other assemblies of blocks or tiles configured similarly. Tabs bent outward made flush by cooling below memory transition temperature. After insertion in gap and reheating, tabs spring outward.

  17. Effective reinforcement learning following cerebellar damage requires a balance between exploration and motor noise.

    PubMed

    Therrien, Amanda S; Wolpert, Daniel M; Bastian, Amy J

    2016-01-01

    Reinforcement and error-based processes are essential for motor learning, with the cerebellum thought to be required only for the error-based mechanism. Here we examined learning and retention of a reaching skill under both processes. Control subjects learned similarly from reinforcement and error-based feedback, but showed much better retention under reinforcement. To apply reinforcement to cerebellar patients, we developed a closed-loop reinforcement schedule in which task difficulty was controlled based on recent performance. This schedule produced substantial learning in cerebellar patients and controls. Cerebellar patients varied in their learning under reinforcement but fully retained what was learned. In contrast, they showed complete lack of retention in error-based learning. We developed a mechanistic model of the reinforcement task and found that learning depended on a balance between exploration variability and motor noise. While the cerebellar and control groups had similar exploration variability, the patients had greater motor noise and hence learned less. Our results suggest that cerebellar damage indirectly impairs reinforcement learning by increasing motor noise, but does not interfere with the reinforcement mechanism itself. Therefore, reinforcement can be used to learn and retain novel skills, but optimal reinforcement learning requires a balance between exploration variability and motor noise.

  18. Effective reinforcement learning following cerebellar damage requires a balance between exploration and motor noise

    PubMed Central

    Therrien, Amanda S.; Wolpert, Daniel M.

    2016-01-01

    See Miall and Galea (doi: 10.1093/awv343) for a scientific commentary on this article. Reinforcement and error-based processes are essential for motor learning, with the cerebellum thought to be required only for the error-based mechanism. Here we examined learning and retention of a reaching skill under both processes. Control subjects learned similarly from reinforcement and error-based feedback, but showed much better retention under reinforcement. To apply reinforcement to cerebellar patients, we developed a closed-loop reinforcement schedule in which task difficulty was controlled based on recent performance. This schedule produced substantial learning in cerebellar patients and controls. Cerebellar patients varied in their learning under reinforcement but fully retained what was learned. In contrast, they showed complete lack of retention in error-based learning. We developed a mechanistic model of the reinforcement task and found that learning depended on a balance between exploration variability and motor noise. While the cerebellar and control groups had similar exploration variability, the patients had greater motor noise and hence learned less. Our results suggest that cerebellar damage indirectly impairs reinforcement learning by increasing motor noise, but does not interfere with the reinforcement mechanism itself. Therefore, reinforcement can be used to learn and retain novel skills, but optimal reinforcement learning requires a balance between exploration variability and motor noise. PMID:26626368

  19. Habituation of reinforcer effectiveness.

    PubMed

    Lloyd, David R; Medina, Douglas J; Hawk, Larry W; Fosco, Whitney D; Richards, Jerry B

    2014-01-09

    In this paper we propose an integrative model of habituation of reinforcer effectiveness (HRE) that links behavioral- and neural-based explanations of reinforcement. We argue that HRE is a fundamental property of reinforcing stimuli. Most reinforcement models implicitly suggest that the effectiveness of a reinforcer is stable across repeated presentations. In contrast, an HRE approach predicts decreased effectiveness due to repeated presentation. We argue that repeated presentation of reinforcing stimuli decreases their effectiveness and that these decreases are described by the behavioral characteristics of habituation (McSweeney and Murphy, 2009; Rankin etal., 2009). We describe a neural model that postulates a positive association between dopamine neurotransmission and HRE. We present evidence that stimulant drugs, which artificially increase dopamine neurotransmission, disrupt (slow) normally occurring HRE and also provide evidence that stimulant drugs have differential effects on operant responding maintained by reinforcers with rapid vs. slow HRE rates. We hypothesize that abnormal HRE due to genetic and/or environmental factors may underlie some behavioral disorders. For example, recent research indicates that slow-HRE is predictive of obesity. In contrast ADHD may reflect "accelerated-HRE." Consideration of HRE is important for the development of effective reinforcement-based treatments. Finally, we point out that most of the reinforcing stimuli that regulate daily behavior are non-consumable environmental/social reinforcers which have rapid-HRE. The almost exclusive use of consumable reinforcers with slow-HRE in pre-clinical studies with animals may have caused the importance of HRE to be overlooked. Further study of reinforcing stimuli with rapid-HRE is needed in order to understand how habituation and reinforcement interact and regulate behavior.

  20. Habituation of reinforcer effectiveness

    PubMed Central

    Lloyd, David R.; Medina, Douglas J.; Hawk, Larry W.; Fosco, Whitney D.; Richards, Jerry B.

    2014-01-01

    In this paper we propose an integrative model of habituation of reinforcer effectiveness (HRE) that links behavioral- and neural-based explanations of reinforcement. We argue that HRE is a fundamental property of reinforcing stimuli. Most reinforcement models implicitly suggest that the effectiveness of a reinforcer is stable across repeated presentations. In contrast, an HRE approach predicts decreased effectiveness due to repeated presentation. We argue that repeated presentation of reinforcing stimuli decreases their effectiveness and that these decreases are described by the behavioral characteristics of habituation (McSweeney and Murphy, 2009; Rankin etal., 2009). We describe a neural model that postulates a positive association between dopamine neurotransmission and HRE. We present evidence that stimulant drugs, which artificially increase dopamine neurotransmission, disrupt (slow) normally occurring HRE and also provide evidence that stimulant drugs have differential effects on operant responding maintained by reinforcers with rapid vs. slow HRE rates. We hypothesize that abnormal HRE due to genetic and/or environmental factors may underlie some behavioral disorders. For example, recent research indicates that slow-HRE is predictive of obesity. In contrast ADHD may reflect “accelerated-HRE.” Consideration of HRE is important for the development of effective reinforcement-based treatments. Finally, we point out that most of the reinforcing stimuli that regulate daily behavior are non-consumable environmental/social reinforcers which have rapid-HRE. The almost exclusive use of consumable reinforcers with slow-HRE in pre-clinical studies with animals may have caused the importance of HRE to be overlooked. Further study of reinforcing stimuli with rapid-HRE is needed in order to understand how habituation and reinforcement interact and regulate behavior. PMID:24409128

  1. [Effects of ground cover and water-retaining agent on winter wheat growth and precipitation utilization].

    PubMed

    Wu, Ji-Cheng; Guan, Xiu-Juan; Yang, Yong-Hui

    2011-01-01

    An investigation was made at a hilly upland in western Henan Province to understand the effects of water-retaining agent (0, 45, and 60 kg x hm(-2)), straw mulching (3000 and 6000 kg x hm(-2)), and plastic mulching (thickness < 0.005 mm) on winter wheat growth, soil moisture and nutrition conditions, and precipitation use. All the three measures promoted winter wheat growth, enhanced grain yield and precipitation use efficiency, and improved soil moisture and nutritional regimes. These positive effects were more obvious when the straw- or plastic mulching was combined with the use of water-retaining agent. Comparing with the control, all the measures increased the soil moisture content at different growth stages by 0.1%-6.5%. Plastic film mulching had the best water-retention effect before jointing stage, whereas water-retaining agent showed its best effect after jointing stage. Soil moisture content was the lowest at flowering and grain-filling stages. Land cover increased the grain yield by 2.6%-20.1%. The yield increment was the greatest (14.2%-20.1%) by the combined use of straw mulching and water-retaining agent, followed by plastic mulching combined with water-retaining agent (11.9% on average). Land cover also improved the precipitation use efficiency (0.4-3.2 kg x mm(-1) x hm(-2)) in a similar trend as the grain yield. This study showed that land cover and water-retaining agent improved soil moisture and nutrition conditions and precipitation utilization, which in turn, promoted the tillering of winter wheat, and increased the grain number per ear and the 1000-grain mass.

  2. Evaluation of Histological Impacts of Three Types of Orthodontic Fixed Retainers on Periodontium of Rabbits

    PubMed Central

    Oshagh, Morteza; Heidary, Somayeh; Dehghani Nazhvani, Ali; Koohpeima, Fatemeh; Koohi Hosseinabadi, Omid

    2014-01-01

    Statement of the Problem: Fixed retainers were developed to maintain incisor alignments after orthodontic treatments. Although the effects of fixed retainers on periodontal health are clinically studied, no studies have still evaluated the histological changes in the periodontium after the placement of thefixed retainers. Purpose: The aim of this study was to evaluate the effects of customised retainers on periodontium histologically. Materials and Method: Forty pairs of maxillary and mandibular central incisors of twenty rabbits were randomly divided into four equal groups: The first group was considered as the control and in the second group, Fiber Reinforced Composite (FRC), in the third group, 0.014 inch stainless steel (SS) wire and in the fourth group, 0.175 inch multistrand stainless steel (MSS) wire were bonded on the labial surfaces of the incisors. After sixty days; animals' periodontium were evaluated histologically. Results: The number of bone resorption lacuna in the control group was significantly less than FRC and 0.014 SS groups. The periodontal vessel count and their diameter in the control group was significantly lower than the other groups. The pulp vessel count and their diameter in controls were significantly more than the 0.014 SS and the 0.175 MSS groups. Conclusion: Findings of this study suggest that FRC fixed retainer might cause detrimental effects on the periodontal ligaments and supporting bone and the 0.014- inch and 0.175- inch fixed retainers can cause hyalinization and possibly the necrosis of the pulp. PMID:25191658

  3. Thermal shock behavior of fiber-reinforced composites

    SciTech Connect

    Wang, H.; Singh, R.N.; Beecher, S.C.; Dinwiddie, R.B.

    1995-02-01

    The thermal shock behavior of three types of continuous fiber-reinforced ceramic composites (Nextel{trademark} or Nicalon{trademark} fiber-reinforced chemical vapor infiltrated or polymer-derived SiC matrix composites) was studied using the water quench technique. The thermal shock induced damage was characterized by both destructive and nondestructive techniques. As compared with monolithic ceramics, the continuous fiber-reinforced ceramic composites were capable of preventing catastrophic failure caused by thermal shock and were able to retain a significant portion of their original strength at {Delta}{Tau} = 1000{degrees}C. The nondestructive techniques involved measuring the thermal diffusivity by the flash technique and determining the Young`s modulus by the dynamic resonance method. It has been demonstrated that these nondestructive techniques can detect damage induced by thermal shock and are more sensitive in detecting damage in the early stage than the conventional destructive technique of measuring the retained strength.

  4. Reinforcement Learning: A Tutorial.

    DTIC Science & Technology

    1997-01-01

    The purpose of this tutorial is to provide an introduction to reinforcement learning (RL) at a level easily understood by students and researchers in...provides a simple example to develop intuition of the underlying dynamic programming mechanism. In Section (2) the parts of a reinforcement learning problem... reinforcement learning algorithms. These include TD(lambda) and both the residual and direct forms of value iteration, Q-learning, and advantage learning

  5. Acquisition and Retaining Granular Samples via a Rotating Coring Bit

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart

    2013-01-01

    This device takes advantage of the centrifugal forces that are generated when a coring bit is rotated, and a granular sample is entered into the bit while it is spinning, making it adhere to the internal wall of the bit, where it compacts itself into the wall of the bit. The bit can be specially designed to increase the effectiveness of regolith capturing while turning and penetrating the subsurface. The bit teeth can be oriented such that they direct the regolith toward the bit axis during the rotation of the bit. The bit can be designed with an internal flute that directs the regolith upward inside the bit. The use of both the teeth and flute can be implemented in the same bit. The bit can also be designed with an internal spiral into which the various particles wedge. In another implementation, the bit can be designed to collect regolith primarily from a specific depth. For that implementation, the bit can be designed such that when turning one way, the teeth guide the regolith outward of the bit and when turning in the opposite direction, the teeth will guide the regolith inward into the bit internal section. This mechanism can be implemented with or without an internal flute. The device is based on the use of a spinning coring bit (hollow interior) as a means of retaining granular sample, and the acquisition is done by inserting the bit into the subsurface of a regolith, soil, or powder. To demonstrate the concept, a commercial drill and a coring bit were used. The bit was turned and inserted into the soil that was contained in a bucket. While spinning the bit (at speeds of 600 to 700 RPM), the drill was lifted and the soil was retained inside the bit. To prove this point, the drill was turned horizontally, and the acquired soil was still inside the bit. The basic theory behind the process of retaining unconsolidated mass that can be acquired by the centrifugal forces of the bit is determined by noting that in order to stay inside the interior of the bit, the

  6. Fiber reinforced hybrid phenolic foam

    NASA Astrophysics Data System (ADS)

    Desai, Amit

    Hybrid composites in recent times have been developed by using more than one type of fiber reinforcement to bestow synergistic properties of the chosen filler and matrix and also facilitating the design of materials with specific properties matched to end use. However, the studies for hybrid foams have been very limited because of problems related to fiber dispersion in matrix, non uniform mixing due to presence of more than one filler and partially cured foams. An effective approach to synthesize hybrid phenolic foam has been proposed and investigated here. Hybrid composite phenolic foams were reinforced with chopped glass and aramid fibers in varied proportions. On assessing mechanical properties in compression and shear several interesting facts surfaced but overall hybrid phenolic foams exhibited a more graceful failure, greater resistance to cracking and were significantly stiffer and stronger than foams with only glass and aramid fibers. The optimum fiber ratio for the reinforced hybrid phenolic foam system was found to be 1:1 ratio of glass to aramid fibers. Also, the properties of hybrid foam were found to deviate from rule of mixture (ROM) and thus the existing theories of fiber reinforcement fell short in explaining their complex behavior. In an attempt to describe and predict mechanical behavior of hybrid foams a statistical design tool using analysis of variance technique was employed. The utilization of a statistical model for predicting foam properties was found to be an appropriate tool that affords a global perspective of the influence of process variables such as fiber weight fraction, fiber length etc. on foam properties (elastic modulus and strength). Similar approach could be extended to study other fiber composite foam systems such as polyurethane, epoxy etc. and doing so will reduce the number of experimental iterations needed to optimize foam properties and identify critical process variables. Diffusivity, accelerated aging and flammability

  7. Retained laser fibre: insights and management.

    PubMed

    Lekich, C; Hannah, P

    2014-06-01

    To describe a case of retained endovenous laser fibre. To review the literature and Food and Drug Administration device failure reports. To suggest protocols for avoiding this complication and a method of removal. A case of retained fibre removal is described. Fibre removal techniques in vivo and ex vivo in a bovine model on the laboratory bench are presented. Successful in vivo and ex vivo fibre removal was performed using duplex ultrasound scan guided phlebectomy techniques. Unexplained measured fibre-length discrepancies due to misleading manufacturer's packaging was discovered. Simple ultrasound-guided micro-phlebectomy techniques can be used to remove retained laser fibres in the office environment. Laser fibre length measurements before and after treatment are recommended. Some preventive guidelines are described to avoid, or at least diagnose immediately, this complication, such as the 'Laser Eclipse Sign'. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Retained garden fork following cranial stab injury.

    PubMed

    Gonya, Sonwabile; Mbatha, Andile; Moyeni, Nondabula; Enicker, Basil

    2016-01-07

    Retained garden fork is a rare complication of penetrating cranial trauma. Retained knife blade is the most commonly reported presentation. We report an unusual case of a 30-year-old male patient treated at our institution, who presented with a retained garden fork following a stab to the head, with no associated neurological deficits. Computerized tomographic scan of the brain was performed preoperatively to assess the trajectory of the weapon and parenchymal injury. A craniectomy was performed to facilitate removal of the weapon in the operating theatre under general anaesthesia. Intravenous prophylactic antibiotics were administered pre- and postoperatively to prevent septic complications. The patient recovered well and was discharged home. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

  9. Ammonia Results Review for Retained Gas Sampling

    SciTech Connect

    Mahoney, Lenna A.

    2000-09-20

    This report was prepared as part of a task supporting the deployment of the retained gas sampler (RGS) system in Flammable Gas Watch List Tanks. The emphasis of this report is on presenting supplemental information about the ammonia measurements resulting from retained gas sampling of Tanks 241-AW-101, A-101, AN-105, AN-104, AN-103, U-103, S-106, BY-101, BY-109, SX-106, AX-101, S-102, S-111, U-109, and SY-101. This information provides a better understanding of the accuracy of past RGS ammonia measurements, which will assist in determining flammable and toxicological hazards.

  10. Retained crossbow bolt after penetrating facial trauma.

    PubMed

    Shah, Manan U; Sridhara, Shankar K; Wolf, Jeffrey S; Ambro, Bryan T

    2016-01-01

    We present an unusual case of a retained crossbow bolt in the maxillofacial area of a 31-year-old man. While crossbow injuries are rare, this case is of interest because otolaryngologists are often faced with treating retained foreign objects after penetrating facial trauma. These cases are difficult to manage because of the complexity and variety of injuries that can occur during both the initial trauma and the removal. We focus on the management of the bolt's removal and provide a brief discussion of the relevant literature on crossbow injuries to the head and neck.

  11. Retained gas sampler interim safety assessment

    SciTech Connect

    Pasamehmetoglu, K.O.; Miller, W.O.; Unal, C.; Fujita, R.K.

    1995-01-13

    This safety assessment addresses the proposed action to install, operate, and remove a Retained Gas Sampler (RGS) in Tank 101-SY at Hanford. Purpose of the RGS is to help characterize the gas species retained in the tank waste; the information will be used to refine models that predict the gas-producing behavior of the waste tank. The RGS will take samples of the tank from top to bottom; these samples will be analyzed for gas constituents. The proposed action is required as part of an evaluation of mitigation concepts for eliminating episodic gas releases that result in high hydrogen concentrations in the tank dome space.

  12. Hierarchical Multiagent Reinforcement Learning

    DTIC Science & Technology

    2004-01-25

    In this paper, we investigate the use of hierarchical reinforcement learning (HRL) to speed up the acquisition of cooperative multiagent tasks. We...introduce a hierarchical multiagent reinforcement learning (RL) framework and propose a hierarchical multiagent RL algorithm called Cooperative HRL. In

  13. Composite Intersection Reinforcement

    NASA Technical Reports Server (NTRS)

    Misciagna, David T. (Inventor); Fuhrer, Jessica J. (Inventor); Funk, Robert S. (Inventor); Tolotta, William S. (Inventor)

    2013-01-01

    An assembly and method for manufacturing a composite reinforcement for unitizing a structure are provided. According to one embodiment, the assembly includes a base having a plurality of pins extending outwardly therefrom to define a structure about which a composite fiber is wound to define a composite reinforcement preform. The assembly also includes a plurality of mandrels positioned adjacent to the base and at least a portion of the composite reinforcement preform, and a cap that is positioned over at least a portion of the plurality of mandrels. The cap is configured to engage each of the mandrels to support the mandrels and the composite reinforcement preform during a curing process to form the composite reinforcement.

  14. Composite intersection reinforcement

    NASA Technical Reports Server (NTRS)

    Misciagna, David T. (Inventor); Fuhrer, Jessica J. (Inventor); Funk, Robert S. (Inventor); Tolotta, William S. (Inventor)

    2010-01-01

    An assembly and method for manufacturing a composite reinforcement for unitizing a structure are provided. According to one embodiment, the assembly includes a base having a plurality of pins extending outwardly therefrom to define a structure about which a composite fiber is wound to define a composite reinforcement preform. The assembly also includes a plurality of mandrels positioned adjacent to the base and at least a portion of the composite reinforcement preform, and a cap that is positioned over at least a portion of the plurality of mandrels. The cap is configured to engage each of the mandrels to support the mandrels and the composite reinforcement preform during a curing process to form the composite reinforcement.

  15. "Reinforcement" in behavior theory.

    PubMed

    Schoenfeld, W N

    1978-01-01

    In its Pavlovian context, "reinforcement" was actually a descriptive term for the functional relation between an unconditional and a conditional stimulus. When it was adopted into operant conditioning, "reinforcement" became the central concept and the key operation, but with new qualifications, new referents, and new expectations. Some behavior theorists believed that "reinforcers" comprise a special and limited class of stimuli or events, and they speculated about what the essential "nature of reinforcement" might be. It is now known that any stimulus can serve a reinforcing function, with due recognition of such parameters as subject species characteristics, stimulus intensity, sensory modality, and schedule of application. This paper comments on these developments from the standpoint of reflex behavior theory.

  16. Retaining African Americans in Higher Education: Challenging Paradigms for Retaining Students, Faculty and Administrators.

    ERIC Educational Resources Information Center

    Jones, Lee, Ed.

    This collection discusses some of the issues surrounding the retention of African Americans in higher education, and it challenges traditional paradigms for retaining African American students, administrators, and faculty at predominantly White colleges. The chapters of part 1, "Retaining African-American Students," are: (1) "Creating an Affirming…

  17. Retaining African Americans in Higher Education: Challenging Paradigms for Retaining Students, Faculty and Administrators.

    ERIC Educational Resources Information Center

    Jones, Lee, Ed.

    This collection discusses some of the issues surrounding the retention of African Americans in higher education, and it challenges traditional paradigms for retaining African American students, administrators, and faculty at predominantly White colleges. The chapters of part 1, "Retaining African-American Students," are: (1) "Creating an Affirming…

  18. Slope reinforcement design using geotextiles and geogrids

    NASA Astrophysics Data System (ADS)

    Setser, Darrell M.

    1990-08-01

    A geotextile is defined by ASTM as: any permeable textile material used with foundation, soil, rock, earth, or any other geotechnical engineering related material, as a integral part of a man-made project, structure, or system. A geogrid is defined as: any geotextile-related material used in a similar manner to geotextiles. They are usually made of plastic, but can be metal or wood. Geotextiles and geogrids are collectively referred to as geosynthetics in this paper. Geosynthetic reinforcement of slopes is a relatively new option available to the civil engineer. Slope angles can be increased and 'poor' soil can be used to construct economical soil-geosynthetic facilities. Uncertainties exist in the complex interaction between the soil and the geosynthetic but there are numerous procedures which ignore this in the design. The design procedures available may be conservative yet still may be an economical alternative when compared to more conventional options.

  19. Placemaking: Attracting and Retaining Today's Students

    ERIC Educational Resources Information Center

    Knight, Brent

    2016-01-01

    Research suggests that the appearance of a college campus--both inside and out--is a significant criterion in college selection. As community colleges are finding it increasingly important to attract and retain students, placemaking is becoming an effective and efficient platform to support recruitment and retention. Placemaking is imagining and…

  20. A simple technique for bonding lingual retainer.

    PubMed

    Hattarki, Rohan S; Rastogi, Shikha

    2015-01-01

    The present article describes an easy method to place a bonded lingual retainer. This technique is also helpful in limiting the flow of the acid etchant used for etching and also limiting the flow of the adhesive on to the lingual surfaces of the teeth.

  1. Corneal bee sting with retained stinger.

    PubMed

    Smith, D G; Roberge, R J

    2001-02-01

    Bee stings of the cornea are rarely reported, but have the potential for causing serious ophthalmologic injuries. We present a case of corneal bee sting with retained stinger apparatus and associated iritis and discuss the pathologic mechanisms of injury, evaluation, and treatment of these uncommon presentations.

  2. Subarachnoid hemorrhage due to retained lumbar drain.

    PubMed

    Guppy, Kern H; Silverthorn, James W; Akins, Paul T

    2011-12-01

    Intrathecal spinal catheters (lumbar drains) are indicated for several medical and surgical conditions. In neurosurgical procedures, they are used to reduce intracranial and intrathecal pressures by diverting CSF. They have also been placed for therapeutic access to administer drugs, and more recently, vascular surgeons have used them to improve spinal cord perfusion during the treatment of thoracic aortic aneurysms. Insertion of these lumbar drains is not without attendant complications. One complication is the shearing of the distal end of the catheter with a resultant retained fragment. The authors report the case of a 65-year-old man who presented with a subarachnoid hemorrhage due to the migration of a retained lumbar drain that sheared off during its removal. To the best of the authors' knowledge, this is the first case of rostral migration of a retained intrathecal catheter causing subarachnoid hemorrhage. The authors review the literature on retained intrathecal spinal catheters, and their findings support either early removal of easily accessible catheters or close monitoring with serial imaging.

  3. Stragegies for Attracting and Retaining Teachers

    ERIC Educational Resources Information Center

    Bland, Paul; Church, Edwin; Luo, Mingchu

    2014-01-01

    Attracting and retaining high quality teachers is a challenge for many school districts. This is especially true in a time of increased accountability and limited resources. This report details best practice in the training, hiring, improvement, and retention of high quality teaching staff. The authors explain how school leaders can attract…

  4. Retained Gas Sampler Calibration and Simulant Tests

    SciTech Connect

    CRAWFORD, B.A.

    2000-01-05

    This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis.

  5. Retaining Excellent Teachers through Effective Leadership

    ERIC Educational Resources Information Center

    Le, Connie

    2013-01-01

    School districts continue to face challenges in retaining talented teachers in their schools. There are many factors that contribute to teacher retention, including working conditions, a lack of leadership support, and poor leadership behavior. In a southeastern U.S. state, local school officials were seeking strategies to provide an excellent…

  6. Recruiting and Retaining Rural Community College Faculty

    ERIC Educational Resources Information Center

    Murray, John P.

    2007-01-01

    Much is being written about a potential shortage of qualified community college faculty. Rural community colleges may be at the greatest disadvantage in attracting and retaining new faculty because they cannot offer the financial, cultural, and social advantages that more urban institutions can. This chapter describes the factors rural community…

  7. Retaining an Ethnically Diverse Teaching Force.

    ERIC Educational Resources Information Center

    Montemayor, Aurelio M.

    1991-01-01

    Discusses problems in attracting and retaining qualified minority group teachers. Some reasons minority teachers leave school districts are lack of an induction process, isolation from other faculty members, economics, and diminishing prestige of teaching. Recommendations involving universities, public schools, state legislators and agencies,…

  8. Retained gas sampler system acceptance test report

    SciTech Connect

    Cannon, N.S., Westinghouse Hanford

    1996-07-18

    Acceptance test results for the Retained Gas Sampler System (RGSS) obtained in the 306E laboratory are reported. The RGSS will be utilized to retrieve and analyze samples from the Hanford flammable gas watch-list tanks to determine the quantity and chemistry of gases confined within the waste.

  9. Placemaking: Attracting and Retaining Today's Students

    ERIC Educational Resources Information Center

    Knight, Brent

    2016-01-01

    Research suggests that the appearance of a college campus--both inside and out--is a significant criterion in college selection. As community colleges are finding it increasingly important to attract and retain students, placemaking is becoming an effective and efficient platform to support recruitment and retention. Placemaking is imagining and…

  10. Recruiting, hiring, and retaining good employees.

    PubMed

    McHenry Martin, Caren

    2014-08-01

    More pharmacists and other health care professionals often feel unprepared when engaged in the hiring process. This can occur both when looking for a new job and when participating as part of the hiring team. In this article, experts in strategies for recruiting, hiring, and retaining employees provide insight into successful strategies for today's changing workplace.

  11. Conventional Weapons Effects on Reinforced Soil Walls.

    DTIC Science & Technology

    1995-03-01

    Form 298 (Rev. 2-89) Prescribed by ANSI Sid. Z39-18 298-102 GENERAL INSTRUCTIONS FOR COMPLETING SF 298 The Report Documentation Page (RDP) is used in...necessitates the use of temporary construction methods: tents, wood frame structures, or lightweight metal buildings. Although functional, these structures...10,000 frames per second or 400 to 40,000 pictures per second. The lens used wa a 45.-m F/2;8 Mamiya M645 lens. Power to the camera was supplied by p

  12. Choice and conditioned reinforcement.

    PubMed Central

    Fantino, E; Freed, D; Preston, R A; Williams, W A

    1991-01-01

    A potential weakness of one formulation of delay-reduction theory is its failure to include a term for rate of conditioned reinforcement, that is, the rate at which the terminal-link stimuli occur in concurrent-chains schedules. The present studies assessed whether or not rate of conditioned reinforcement has an independent effect upon choice. Pigeons responded on either modified concurrent-chains schedules or on comparable concurrent-tandem schedules. The initial link was shortened on only one of two concurrent-chains schedules and on only one of two corresponding concurrent-tandem schedules. This manipulation increased rate of conditioned reinforcement sharply in the chain but not in the tandem schedule. According to a formulation of delay-reduction theory, when the outcomes chosen (the terminal links) are equal, as in Experiment 1, choice should depend only on rate of primary reinforcement; thus, choice should be equivalent for the tandem and chain schedules despite a large difference in rate of conditioned reinforcement. When the outcomes chosen are unequal, however, as in Experiment 2, choice should depend upon both rate of primary reinforcement and relative signaled delay reduction; thus, larger preferences should occur in the chain than in the tandem schedules. These predictions were confirmed, suggesting that increasing the rate of conditioned reinforcement on concurrent-chains schedules may have no independent effect on choice. PMID:2037826

  13. An Alternative Method of Thinning Reinforcer Delivery during Differential Reinforcement

    ERIC Educational Resources Information Center

    Roane, Henry S.; Fisher, Wayne W.; Sgro, Gina M.; Falcomata, Terry S.; Pabico, Robert R.

    2004-01-01

    Differential reinforcement of alternative behavior (DRA) may result in rates of reinforcement that are impractical for caregivers to implement; therefore, recent research has examined methods for thinning reinforcer delivery during DRA. In this study, reinforcer delivery was thinned during DRA by restricting access to the participant's alternative…

  14. Decellularized scaffold of cryopreserved rat kidney retains its recellularization potential

    PubMed Central

    Chani, Baldeep; Puri, Veena; Sobti, Ranbir C.; Jha, Vivekanand; Puri, Sanjeev

    2017-01-01

    The multi-cellular nature of renal tissue makes it the most challenging organ for regeneration. Therefore, till date whole organ transplantations remain the definitive treatment for the end stage renal disease (ESRD). The shortage of available organs for the transplantation has, thus, remained a major concern as well as an unsolved problem. In this regard generation of whole organ scaffold through decellularization followed by regeneration of the whole organ by recellularization is being viewed as a potential alternative for generating functional tissues. Despite its growing interest, the optimal processing to achieve functional organ still remains unsolved. The biggest challenge remains is the time line for obtaining kidney. Keeping these facts in mind, we have assessed the effects of cryostorage (3 months) on renal tissue architecture and its potential for decellularization and recellularization in comparison to the freshly isolated kidneys. The light microscopy exploiting different microscopic stains as well as immuno-histochemistry and Scanning electron microscopy (SEM) demonstrated that ECM framework is well retained following kidney cryopreservation. The strength of these structures was reinforced by calculating mechanical stress which confirmed the similarity between the freshly isolated and cryopreserved tissue. The recellularization of these bio-scaffolds, with mesenchymal stem cells quickly repopulated the decellularized structures irrespective of the kidneys status, i.e. freshly isolated or the cryopreserved. The growth pattern employing mesenchymal stem cells demonstrated their equivalent recellularization potential. Based on these observations, it may be concluded that cryopreserved kidneys can be exploited as scaffolds for future development of functional organ. PMID:28267813

  15. Attracting and retaining nurses in primary care.

    PubMed

    Drennan, Vari; Andrews, Sarah; Sidhu, Rajinder; Peacock, Richard

    2006-06-01

    There is increasing demand for nurses to work in primary care. This is driven in part by the need to retain current levels but also by the modernisation plans for primary care services, which require new roles for nurses, new ways of working and more nurses in primary care settings. While campaigns for increased recruitment of hospital nurses and doctors has been largely successful in recent years, primary care has still to see the impact. This article reports on a Department of Health (England) funded project that aimed to identify strategies and exemplars to assist primary care trusts (PCTs) and the workforce development confederations (WDCs) in strategic health authorities in attracting and retaining nurses to primary care at registered nurse level. It reports on the range of initiatives identified, the perceived benefits and challenges. It concludes by proposing a strategic model for planning for the recruitment and retention of primary care nurses.

  16. GLASS FIBER REINFORCED PLASTICS,

    DTIC Science & Technology

    Contents: Fibrous glass fillers Binders used in the glass plastic industry Method of manufacturing glass plastics and glass plastic articles Properties of fiberglass Primary areas for use of glass fibre reinforced plastics

  17. Retention--retainers may be forever.

    PubMed

    Parker, W S

    1989-06-01

    The very word "retain" means "to hold back or hold secure." From the earliest days of orthodontic tooth movement, many schemes have been proposed to ensure posttreatment stability. The very best research indicates that no solution has been found. A posttreatment routine is recommended. It is suggested that each patient be advised to follow this and further warned that the dental profession does not have any reliable method to predict future dental stability with or without orthodontic treatment.

  18. Retaining nursing faculty beyond retirement age.

    PubMed

    Williamson, Marvel L; Cook, Linda; Salmeron, Lois; Burton, Denise

    2010-01-01

    The number of nursing faculty planning to retire by 2020 is alarming. To develop strategies for retaining faculty, researchers asked: What factors influence the decision by nursing faculty to stay in the workforce past retirement age? What barriers could be removed that would encourage faculty to stay longer? Using Giorgi's analysis method, findings from 6 faculty teaching past retirement age revealed key meaning units and grand themes that match Maslow's Hierarchy of Inborn Needs.

  19. Increasing trend in retained rectal foreign bodies

    PubMed Central

    Ayantunde, Abraham A; Unluer, Zynep

    2016-01-01

    AIM To highlight the rising trend in hospital presentation of foreign bodies retained in the rectum over a 5-year period. METHODS Retrospective review of the cases of retained rectal foreign bodies between 2008 and 2012 was performed. Patients’ clinical data and yearly case presentation with data relating to hospital episodes were collected. Data analysis was by SPSS Inc. Chicago, IL, United States. RESULTS Twenty-five patients presented over a 5-year period with a mean age of 39 (17-62) years and M: F ratio of 2:1. A progressive rise in cases was noted from 2008 to 2012 with 3, 4, 4, 6, 8 recorded patients per year respectively. The majority of the impacted rectal objects were used for self-/partner-eroticism. The commonest retained foreign bodies were sex vibrators and dildos. Ninty-six percent of the patients required extraction while one passed spontaneously. Two and three patients had retrieval in the Emergency Department and on the ward respectively while 19 patients needed examination under anaesthesia for extraction. The mean hospital stay was 19 (2-38) h. Associated psychosocial issues included depression, deliberate self-harm, illicit drug abuse, anxiety and alcoholism. There were no psychosocial problems identified in 15 patients. CONCLUSION There is a progressive rise in hospital presentation of impacted rectal foreign bodies with increasing use of different objects for sexual arousal. PMID:27830039

  20. Retaining latch for a water pit gate

    DOEpatents

    Beale, A.R.

    1997-11-18

    A retaining latch is described for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame. 4 figs.

  1. Guideline Implementation: Prevention of Retained Surgical Items.

    PubMed

    Fencl, Jennifer L

    2016-07-01

    A surgical item unintentionally retained in a patient after an operative or other invasive procedure is a serious, preventable medical error with the potential to cause the patient great harm. Perioperative RNs play a key role in preventing retained surgical items (RSIs). The updated AORN "Guideline for prevention of retained surgical items" provides guidance for implementing a consistent, multidisciplinary approach to RSI prevention; accounting for surgical items; preventing retention of device fragments; reconciling count discrepancies; and using adjunct technologies to supplement manual count procedures. This article focuses on key points of the guideline to help perioperative personnel provide optimal care during a procedure. Key points addressed include taking responsibility for RSI prevention as a team; minimizing distractions, noise, and interruptions during counts; using consistent counting methods; reconciling discrepancies; and participating in performance-improvement activities. Perioperative RNs should review the complete guideline for additional information and for guidance in writing and updating policies and procedures. Copyright © 2016 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  2. Retaining latch for a water pit gate

    SciTech Connect

    Beale, A.R.

    1997-11-18

    A retaining latch is described for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame. 4 figs.

  3. Retaining latch for a water pit gate

    SciTech Connect

    Beale, Arden R.

    1997-01-01

    A retaining latch for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame.

  4. Fibre-reinforced materials.

    PubMed

    Brown, D

    2000-11-01

    This paper considers the role of fibres in the reinforcement of composite materials, and the significance of the form the fibre takes and the material from which it is made. The current dental applications of fibre reinforcement, including dental cements and splints, fibres made into structures for use in composites, denture bases and the contemporary use of fibres in fixed partial dentures, are reviewed. Their role in biomedical implants is surveyed and their future forecast.

  5. Carbon Nanofiber Reinforced Polymers

    DTIC Science & Technology

    2006-01-01

    2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Carbon Nanofiber Reinforced Polymers 5a. CONTRACT NUMBER 5b...REVIEW Carbon Nanofiber Reinforced Polymers J.N. Baucom, A. Rohatgi, W.R. Pogue III, and J.P. Thomas Materials Science and Technology Division...of mass-produced and inexpensive, discontinuous carbon nanofibers to create a percolated fiber network within a polymeric matrix that will result in

  6. Reinforced Concrete Modeling

    DTIC Science & Technology

    1982-07-01

    AFWL-TR-82-9 AFWL-TR-82-9 REINFORCED CONCRETE MODELING H. L. Schreyer J. W. Jeter, Jr. New Mexico Engineering Reseprch Institute University of New...Subtitle) S. TYPE OF REPORT & PERIOD COVERED REINFORCED CONCRETE MODELING Final Report 6. PERFORMING OtG. REPORT NUMBER NMERI TA8-9 7. AUTHORg) S...loading were identified and used to evaluate current concrete models . Since the endochronic and viscoplastic models provide satisfactory descriptions

  7. Reinforcement learning in scheduling

    NASA Technical Reports Server (NTRS)

    Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

    1994-01-01

    The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

  8. Covert Reinforcement: A Partial Replication.

    ERIC Educational Resources Information Center

    Ripstra, Constance C.; And Others

    A partial replication of an investigation of the effect of covert reinforcement on a perceptual estimation task is described. The study was extended to include an extinction phase. There were five treatment groups: covert reinforcement, neutral scene reinforcement, noncontingent covert reinforcement, and two control groups. Each subject estimated…

  9. The substitutability of reinforcers

    PubMed Central

    Green, Leonard; Freed, Debra E.

    1993-01-01

    Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. PMID:16812696

  10. An evaluation of two differential reinforcement procedures with escape extinction to treat food refusal.

    PubMed Central

    Patel, Meeta R; Piazza, Cathleen C; Martinez, Cheryl J; Volkert, Valerie M; Christine, M Santana

    2002-01-01

    Consumption of solids and liquids occurs as a chain of behaviors that may include accepting, swallowing, and retaining the food or drink. In the current investigation, we evaluated the relative effectiveness of differential reinforcement of the first behavior in the chain (acceptance) versus differential reinforcement for the terminal behavior in the chain (mouth clean). Three children who had been diagnosed with a feeding disorder participated. Acceptance remained at zero when differential reinforcement contingencies were implemented for acceptance or mouth clean. Acceptance and mouth clean increased for all 3 participants once escape extinction was added to the differential reinforcement procedures, independent of whether reinforcement was provided for acceptance or for mouth clean. Maintenance was observed in 2 children when escape extinction was removed from the treatment package. The mechanism by which consumption increased is discussed in relation to positive and negative reinforcement contingencies. PMID:12555908

  11. An evaluation of two differential reinforcement procedures with escape extinction to treat food refusal.

    PubMed

    Patel, Meeta R; Piazza, Cathleen C; Martinez, Cheryl J; Volkert, Valerie M; Christine, M Santana

    2002-01-01

    Consumption of solids and liquids occurs as a chain of behaviors that may include accepting, swallowing, and retaining the food or drink. In the current investigation, we evaluated the relative effectiveness of differential reinforcement of the first behavior in the chain (acceptance) versus differential reinforcement for the terminal behavior in the chain (mouth clean). Three children who had been diagnosed with a feeding disorder participated. Acceptance remained at zero when differential reinforcement contingencies were implemented for acceptance or mouth clean. Acceptance and mouth clean increased for all 3 participants once escape extinction was added to the differential reinforcement procedures, independent of whether reinforcement was provided for acceptance or for mouth clean. Maintenance was observed in 2 children when escape extinction was removed from the treatment package. The mechanism by which consumption increased is discussed in relation to positive and negative reinforcement contingencies.

  12. Application of FBG Sensing Technology in Stability Analysis of Geogrid-Reinforced Slope.

    PubMed

    Sun, Yijie; Xu, Hongzhong; Gu, Peng; Hu, Wenjie

    2017-03-15

    By installing FBG sensors on the geogrids, smart geogrids can both reinforce and monitor the stability for geogrid-reinforced slopes. In this paper, a geogrid-reinforced sand slope model test is conducted in the laboratory and fiber Bragg grating (FBG) sensing technology is used to measure the strain distribution of the geogrid. Based on the model test, the performance of the reinforced soil slope is simulated by finite element software Midas-GTS, and the stability of the reinforced soil slope is analyzed by strength reduction method. The relationship between the geogrid strain and the factor of safety is set up. The results indicate that the measured strain and calculated results agree very well. The geogrid strain measured by FBG sensor can be applied to evaluate the stability of geogrid-reinforced sand slopes.

  13. Application of FBG Sensing Technology in Stability Analysis of Geogrid-Reinforced Slope

    PubMed Central

    Sun, Yijie; Xu, Hongzhong; Gu, Peng; Hu, Wenjie

    2017-01-01

    By installing FBG sensors on the geogrids, smart geogrids can both reinforce and monitor the stability for geogrid-reinforced slopes. In this paper, a geogrid-reinforced sand slope model test is conducted in the laboratory and fiber Bragg grating (FBG) sensing technology is used to measure the strain distribution of the geogrid. Based on the model test, the performance of the reinforced soil slope is simulated by finite element software Midas-GTS, and the stability of the reinforced soil slope is analyzed by strength reduction method. The relationship between the geogrid strain and the factor of safety is set up. The results indicate that the measured strain and calculated results agree very well. The geogrid strain measured by FBG sensor can be applied to evaluate the stability of geogrid-reinforced sand slopes. PMID:28294995

  14. Efficacy of vegetated buffer strips for retaining Cryptosporidium parvum.

    PubMed

    Tate, Kenneth W; Pereira, Maria Das Gracas C; Atwill, Edward R

    2004-01-01

    Overland and shallow subsurface hydrologic transport of pathogenic Cryptosporidium parvum oocysts from cattle feces into surface drinking water supplies is a major concern on annual grasslands in California's central and southern Sierra Nevada foothills. Soil boxes (0.5 m wide x 1.1 m long x 0.3 m deep) were used to evaluate the ability of grass vegetated buffer strips to retain 2 x 10(8) spiked C. parvum oocysts in 200-g fecal deposits during simulated rainfall intensities of 30 to 47.5 mm/h over 2 h. Buffers were comprised of Ahwahnee sandy loam (coarse-loamy, mixed, active, thermic Mollic Haploxeralfs; 78:18:4 sand to silt to clay ratio; dry bulk density = 1.4 g/cm(3)) set at 5 to 20% land slope, and >/=95% grass cover (grass stubble height = 10 cm; biomass = 900 kg/ha dry weight). Total number of oocysts discharged from each soil box (combined overland and subsurface flow) during the 120-min simulation ranged from 1.5 x 10(6) to 23.9 x 10(6) oocysts. Observed overall mean log(10) reduction of total C. parvum flux per meter of vegetated buffer was 1.44, 1.19, and 1.18 for buffers at 5, 12, and 20% land slope, respectively. Rainfall application rate (mm/h) was strongly associated with oocyst flux from these vegetated buffers, resulting in a decrease of 2 to 4% in the log(10) reduction per meter buffer for every additional mm/h applied to the soil box. These results support the use of strategically placed vegetated buffers as one of several management strategies that can reduce the risk of waterborne C. parvum attributable to extensive cattle grazing on annual grassland watersheds.

  15. Preference for 50% reinforcement over 75% reinforcement by pigeons.

    PubMed

    Gipson, Cassandra D; Alessandri, Jérôme J D; Miller, Holly C; Zentall, Thomas R

    2009-11-01

    When pigeons are given a choice between an initial-link alternative that results in either a terminal-link stimulus correlated with 100% reinforcement or a stimulus correlated with 0% reinforcement (overall 50% reinforcement) and another initial-link alternative that always results in a terminal-link stimulus correlated with 100% reinforcement, some pigeons show a preference for the initial-link alternative correlated with 50% reinforcement. Using this procedure, in Experiment 1, we found a relatively modest preference for 100% over 50% reinforcement. In Experiment 2, we decreased the reinforcement density for the second initial-link alternative to 75% and found a significant preference for the 50% reinforcement initial-link alternative. It may be that this "maladaptive" behavior results from a positive contrast between the expectation of reinforcement correlated with the 50% reinforcement initial-link alternative and the terminal-link stimulus correlated with 100% reinforcement. But apparently, the complementary negative contrast does not develop between the expectation of reinforcement correlated with the 50% reinforcement initial-link alternative and the terminal-link stimulus correlated with 0% reinforcement that often follow. Such paradoxical choice may account for certain human appetitive risk-taking behavior (e.g., gambling) as well.

  16. Nitroglycerin for management of retained placenta.

    PubMed

    Abdel-Aleem, Hany; Abdel-Aleem, Mahmoud A; Shaaban, Omar M

    2015-11-12

    Retained placenta affects 0.5% to 3% of women following delivery, with considerable morbidity if left untreated. Use of nitroglycerin (NTG), either alone or in combination with uterotonics, may be of value to minimise the need for manual removal of the placenta in theatre under anaesthesia. To evaluate the benefits and harms of NTG as a tocolytic, either alone or in addition to uterotonics, in the management of retained placenta. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 January 2015), reference lists of retrieved studies and contacted experts in the field. Any adequately randomised controlled trial (RCT) comparing the use of NTG, either alone or in combination with uterotonics, with no intervention or with other interventions in the management of retained placenta. All women having a vaginal delivery with a retained placenta, regardless of the management of the third stage of labour (expectant or active). We included all trials with haemodynamically stable women in whom the placenta was not delivered at least within 15 minutes after delivery of the baby. Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We included three randomised controlled trials (RCTs) with 175 women. The three published RCTs compared NTG alone versus placebo. The detachment status of retained placenta was unknown in all three RCTs. Collectively, among the three included trials, two were judged to be at low risk of bias and the third trial was judged to be at high risk of bias for two domains: incomplete outcome data and selective reporting. The three trials reported seven out of 23 of the review's pre-specified outcomes.The primary outcome "manual removal of the placenta" was reported in all three studies. No differences were seen between NTG and placebo for manual removal of the placenta (average risk ratio (RR) 0.83, 95% confidence interval (CI) 0.47 to 1.46; women = 175; I

  17. Counting matters: lessons from the root cause analysis of a retained surgical item.

    PubMed

    Agrawal, Abha

    2012-12-01

    Retained surgical items (RSIs), such as a sponge, instrument, or needle, after a surgery or invasive procedure is an uncommon but potentially serious event associated with significant morbidity and mortality. A 27-year-old woman was discovered to have a retained vaginal sponge a week after she underwent the repair of a vaginal tear following normal vaginal delivery. The retained sponge was removed with no further complications. The fundamental error involved the obstetric team's failure to perform the standard protocol of counting sponges before, as well as after, the procedure. This was attributed to a lack of reminders to perform the count, relatively recent implementation of the sponge-count policy, and a breakdown in teamwork and communication between physicians and nurses. The corrective actions focused on systems improvement, as opposed to the human error of the memory lapse. The sponge-counting process was reinforced by incorporating a sign-out at the end of obstetric procedures to ensure that the counts have been done and any discrepancies addressed. A specialized delivery note with mandatory field to document sponge count was implemented in the electronic health record as an additional reminder. All staff participated in a teamwork and communication training program. Since the incident's occurrence in 2010, the staff has demonstrated 100% compliance with the corrective actions, and a retained surgical item complication has not recurred. Individual accountability must be balanced with systems improvement, given that most medical errors are a result of fallible humans working in chaotic, unpredictable, and complex clinical environment.

  18. Retained Surgical Foreign Bodies after Surgery

    PubMed Central

    Zejnullahu, Valon A.; Bicaj, Besnik X.; Zejnullahu, Vjosa A.; Hamza, Astrit R.

    2017-01-01

    The problem of retained surgical bodies (RSB) after surgery is an issue for surgeons, hospitals and the entire medical team. They have potentially harmful consequences for the patient as they can be life threatening and usually, a further operation is necessary. The incidence of RSB is between 0.3 to 1.0 per 1,000 abdominal operations, and they occur due to a lack of organisation and communication between surgical staff during the process. Typically, the RSB are surgical sponges and instruments located in the abdomen, retroperitoneum and pelvis. PMID:28293325

  19. Self Retaining Anti-Rotation Key

    NASA Technical Reports Server (NTRS)

    Dixon, Alan Benjamin Christopher (Inventor)

    2015-01-01

    Anti-rotation keys are typically used in applications where an end of a threaded stud is received in a housing, and where the opposite end of the stud projects from the housing to allow attachment of another component to the housing. Once partially received in the housing, further rotation of the stud is prevented by an anti-rotation key. The disclosed anti-rotation key is self-retaining, in that it prevents itself from "backing out" of the channel due to vibration or thermal expansion of the housing, etc., while also being removable from the channel if desired.

  20. Retaining Device For One-Piece Battery

    DOEpatents

    Gilabert, Claude; Leturque, Michel; Verhoog, Roclof

    2000-08-01

    The present invention consists of a device for retaining a one-piece battery with a prismatic casing having two longitudinal walls and two transverse walls. The device contains two plates applied to respective transverse walls and at least one cinching mechanism for the plates consisting of at least one flat strip closed on itself surrounding the longitudinal walls and the transverse walls are provided with the plates. The device is characterized in that at least one of the plates contains at least one recessed housing and the strip closely follows the shape of the housing.

  1. HIV: seek, test, treat, and retain.

    PubMed

    Normand, Jacques; Montaner, Julio; Fang, Chi-Tai; Wu, Zunyou; Chen, Yi-Ming

    2013-12-01

    The "HIV: Seek, Test, Treat, and Retain" session was chaired by Dr. Jacques Normand, the Director of AIDS Research at the U.S. National Institute on Drug Abuse. Dr. Yi-Ming Chen served as the discussant. The three presenters (and their presentation topics) were: Dr. Julio Montaner (Treatment as Prevention-The Key to an AIDS-free Generation), Dr. Chi-Tai Fang (Population-level Effect of Free Access to HAART on Reducing HIV Transmission in Taiwan), and Dr. Zunyou Wu (Challenges in Promoting HIV Test & Treat Strategy in China).

  2. REINFORCER MAGNITUDE ATTENUATES

    PubMed Central

    Pinkston, Jonathan W.; Lamb, R. J.

    2012-01-01

    When given to pigeons, the direct-acting dopamine agonist apomorphine elicits pecking. The response has been likened to foraging pecking because it bears remarkable similarity to foraging behavior, and it is enhanced by food deprivation. On the other hand, other data suggest the response is not related to foraging behavior and may even interfere with food ingestion. Although elicited pecking interferes with food capture, it may selectively alter procurement phases of feeding, which can be isolated in operant preparations. To explore the relation between operant and elicited pecking, we provided pigeons the opportunity to earn different reinforcer magnitudes during experimental sessions. During signaled components, each of 4 pigeons could earn 2-, 4-, or 8-s access to grain for a single peck made at the end of a 5-min interval. In general, responding increased as a function of reinforcer magnitude. Apomorphine increased pecking for 2 pigeons and decreased pecking for the other 2. In both cases, apomorphine was more potent under the component providing the smallest reinforcer magnitude. Analysis of the pattern of pecking across the interval indicated that behavior lost its temporal organization as dose increased. Because apomorphine-induced pecking varied inversely with reinforcer magnitude, we conclude that elicited pecks are not functionally related to food procurement. The data are consistent with the literature on behavioral resistance to change and suggest that the effects of apomorphine may be modulated by prevailing stimulus–reinforcer relationships. PMID:23144505

  3. Waterfowl density on agricultural fields managed to retain water in winter

    USGS Publications Warehouse

    Twedt, D.J.; Nelms, C.O.

    1999-01-01

    Managed water on private and public land provides habitat for wintering waterfowl in the Mississippi Valley, where flood control projects have reduced the area of natural flooding. We compared waterfowl densities on rice, soybean, and moist-soil fields under cooperative agreements to retain water from 1 November through 28 February in Arkansas and Mississippi and assessed temporal changes in waterfowl density during winter in 1991-1992 and 1992-1993. Fields flooded earlier in Arkansas, but retained water later in Mississippi. Over winter, waterfowl densities decreased in Arkansas and increased in Mississippi. Densities of waterfowl, including mallard (Anas platyrhynchos), the most abundant species observed, were greatest on moist-soil fields. However, soybean fields had the greatest densities of northern shoveler (Spatula clypeata).

  4. Braided reinforced composite rods for the internal reinforcement of concrete

    NASA Astrophysics Data System (ADS)

    Gonilho Pereira, C.; Fangueiro, R.; Jalali, S.; Araujo, M.; Marques, P.

    2008-05-01

    This paper reports on the development of braided reinforced composite rods as a substitute for the steel reinforcement in concrete. The research work aims at understanding the mechanical behaviour of core-reinforced braided fabrics and braided reinforced composite rods, namely concerning the influence of the braiding angle, the type of core reinforcement fibre, and preloading and postloading conditions. The core-reinforced braided fabrics were made from polyester fibres for producing braided structures, and E-glass, carbon, HT polyethylene, and sisal fibres were used for the core reinforcement. The braided reinforced composite rods were obtained by impregnating the core-reinforced braided fabric with a vinyl ester resin. The preloading of the core-reinforced braided fabrics and the postloading of the braided reinforced composite rods were performed in three and two stages, respectively. The results of tensile tests carried out on different samples of core-reinforced braided fabrics are presented and discussed. The tensile and bending properties of the braided reinforced composite rods have been evaluated, and the results obtained are presented, discussed, and compared with those of conventional materials, such as steel.

  5. Retained surgical sponges, needles and instruments

    PubMed Central

    Hariharan, D

    2013-01-01

    Introduction Retained sponges and instruments (RSI) due to surgery are a recognised medical ‘never event’ and have catastrophic implications for patients, healthcare professionals and medical care providers. The aim of this review was to elucidate the extent of the problem of RSI and to identify preventative strategies. Methods A comprehensive literature search was performed on MEDLINE®, Embase™, the Science Citation Index and Google™ Scholar for articles published in English between January 2000 and June 2012. Studies outlining the incidence, risk, management and attempts to prevent RSI following surgical intervention were retrieved. Results The overall incidence of RSI is low although its incidence is substantially higher in operations performed on open cavities. Sponges are the most commonly retained item when compared with needles and instruments. Clinical presentation is varied, leading to avoidable morbidity, and the error is indefensible medicolegally. Risk factors include emergency operations, operations involving unexpected change in procedure, raised body mass index, and a failure to perform accurate sponge and instrument counts. The existing strategy for prevention is manual counting of sponges and instruments undertaken by surgical personnel. This, however, is fallible. Computer assisted counting of sponges using barcodes and gauze sponges tagged with a radiofrequency identification device aiding manual counting have been trialled recently, with success. Conclusions Vigilance among operating theatre personnel is paramount if RSI is to be prevented. Prospective multicentre trials to assess efficacy of new technologies aiding manual counting should be undertaken if this medical error is to be eliminated completely. PMID:23484986

  6. Retaining latch for a water pit gate

    SciTech Connect

    Beale, A.R.

    1996-12-31

    The present invention relates to retaining devices which are used to latch two elements or parts together and, more particularly, to gate latches for use in locking a gate to a wall bracket in a water pit utilized to store or handle hazardous materials. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame.

  7. Retained surgical sponges, needles and instruments.

    PubMed

    Hariharan, D; Lobo, D N

    2013-03-01

    Retained sponges and instruments (RSI) due to surgery are a recognised medical 'never event' and have catastrophic implications for patients, healthcare professionals and medical care providers. The aim of this review was to elucidate the extent of the problem of RSI and to identify preventative strategies. A comprehensive literature search was performed on MEDLINE(®), Embase™, the Science Citation Index and Google™ Scholar for articles published in English between January 2000 and June 2012. Studies outlining the incidence, risk, management and attempts to prevent RSI following surgical intervention were retrieved. The overall incidence of RSI is low although its incidence is substantially higher in operations performed on open cavities. Sponges are the most commonly retained item when compared with needles and instruments. Clinical presentation is varied, leading to avoidable morbidity, and the error is indefensible medicolegally. Risk factors include emergency operations, operations involving unexpected change in procedure, raised body mass index, and a failure to perform accurate sponge and instrument counts. The existing strategy for prevention is manual counting of sponges and instruments undertaken by surgical personnel. This, however, is fallible. Computer assisted counting of sponges using barcodes and gauze sponges tagged with a radiofrequency identification device aiding manual counting have been trialled recently, with success. Vigilance among operating theatre personnel is paramount if RSI is to be prevented. Prospective multicentre trials to assess efficacy of new technologies aiding manual counting should be undertaken if this medical error is to be eliminated completely.

  8. Choice and reinforcement delay

    SciTech Connect

    Gentry, G.D.; Marr, M.J.

    1980-01-01

    Previous studies of choice between two delayed reinforcers have indicated that the relative immediacy of the reinforcer is a major determinant of the relative frequency of responding. Parallel studies of choice between two interresponse times have found exceptions to this generality. The present study looked at the choice by pigeons between two delays, one of which was always four times longer than the other, but whose absolute durations were varied across conditions. The results indicated that choice is not uniquely determined by the relative immediacy of reinforcement, but that absolute delays are also involved. Models for concurrent chained schedules appear to be more applicable to the present data than the matching relation; however, these too failed to predict choice for long delays.

  9. Stochastic reinforcement benefits skill acquisition.

    PubMed

    Dayan, Eran; Averbeck, Bruno B; Richmond, Barry J; Cohen, Leonardo G

    2014-02-14

    Learning complex skills is driven by reinforcement, which facilitates both online within-session gains and retention of the acquired skills. Yet, in ecologically relevant situations, skills are often acquired when mapping between actions and rewarding outcomes is unknown to the learning agent, resulting in reinforcement schedules of a stochastic nature. Here we trained subjects on a visuomotor learning task, comparing reinforcement schedules with higher, lower, or no stochasticity. Training under higher levels of stochastic reinforcement benefited skill acquisition, enhancing both online gains and long-term retention. These findings indicate that the enhancing effects of reinforcement on skill acquisition depend on reinforcement schedules.

  10. Reinforcement pathology and obesity.

    PubMed

    Carr, Katelyn A; Daniel, Tinuke Oluyomi; Lin, Henry; Epstein, Leonard H

    2011-09-01

    Obesity is, in part, a result of positive energy balance or energy intake exceeding physiological needs. Excess energy intake is determined by a series of food choices over time. These choices involve both motivational and executive function processes. Problems arise when there is excessive motivation to eat and low impulse control, a situation we have termed reinforcement pathology. Motivational and executive function processes have also been implicated in the development of drug dependence and addiction. In this review we discuss the application of reinforcement pathology to obesity, and implications of this approach for obesity treatment.

  11. Evaluating the influence of postsession reinforcement on choice of reinforcers.

    PubMed

    Kodak, Tiffany; Lerman, Dorothea C; Call, Nathan

    2007-01-01

    Factors that influence reinforcer choice have been examined in a number of applied studies (e.g., Neef, Mace, Shea, & Shade, 1992; Shore, Iwata, DeLeon, Kahng, & Smith, 1997; Tustin, 1994). However, no applied studies have evaluated the effects of postsession reinforcement on choice between concurrently available reinforcers, even though basic findings indicate that this is an important factor to consider (Hursh, 1978; Zeiler, 1999). In this bridge investigation, we evaluated the influence of postsession reinforcement on choice of two food items when task responding was reinforced on progressive-ratio schedules. Participants were 3 children who had been diagnosed with developmental disabilities. Results indicated that response allocation shifted from one food item to the other food item under thinner schedules of reinforcement when no postsession reinforcement was provided. These findings suggest that the efficacy of instructional programs or treatments for problem behavior may be improved by restricting reinforcers outside treatment sessions.

  12. Pedological memory in forest soil development

    Treesearch

    Jonathan D. Phillips; Daniel A. Marion

    2004-01-01

    Individual trees may have significant impacts on soil morphology. If these impacts are non-random such that some microsites are repeatedly preferentially affected by trees, complex local spatial variability of soils would result. A model of self-reinforcing pedologic influences of trees (SRPIT) is proposed to explain patterns of soil variability in the Ouachita...

  13. Reinforcement of hydrogels using three-dimensionally printed microfibres

    NASA Astrophysics Data System (ADS)

    Visser, Jetze; Melchels, Ferry P. W.; Jeon, June E.; van Bussel, Erik M.; Kimpton, Laura S.; Byrne, Helen M.; Dhert, Wouter J. A.; Dalton, Paul D.; Hutmacher, Dietmar W.; Malda, Jos

    2015-04-01

    Despite intensive research, hydrogels currently available for tissue repair in the musculoskeletal system are unable to meet the mechanical, as well as the biological, requirements for successful outcomes. Here we reinforce soft hydrogels with highly organized, high-porosity microfibre networks that are 3D-printed with a technique termed as melt electrospinning writing. We show that the stiffness of the gel/scaffold composites increases synergistically (up to 54-fold), compared with hydrogels or microfibre scaffolds alone. Modelling affirms that reinforcement with defined microscale structures is applicable to numerous hydrogels. The stiffness and elasticity of the composites approach that of articular cartilage tissue. Human chondrocytes embedded in the composites are viable, retain their round morphology and are responsive to an in vitro physiological loading regime in terms of gene expression and matrix production. The current approach of reinforcing hydrogels with 3D-printed microfibres offers a fundament for producing tissue constructs with biological and mechanical compatibility.

  14. Reinforcement Schedule Effects on Long-Term Behavior Change

    PubMed Central

    Roll, John M.; McPherson, Sterling; Cameron, Jennifer M.; Howell, Donelle N.

    2015-01-01

    Objective The primary aim of this study was to determine whether different schedules of contingency management (CM), in conjunction with psychosocial treatment, produced different rates of abstinence and treatment attendance among individuals dependent on methamphetamine. Methods Individuals were randomized into 1 of 3 conditions that sought to equate total potential reinforcer magnitude while varying the frequency with which reinforcement was delivered, and comparing these results to those obtained when psychosocial support alone was used. Results Results indicate that all 3 CM schedules occasioned more abstinent attendance than the group only receiving psychosocial treatment. However, the 3 CM conditions did not differ in any appreciable way. Conclusions These results suggest that treatment providers may be able to decrease the frequency of reinforcer delivery in CM paradigms while retaining efficacy to treat psychostimulant use disorders. PMID:26139942

  15. Reinforcement Magnitude: An Evaluation of Preference and Reinforcer Efficacy

    ERIC Educational Resources Information Center

    Trosclair-Lasserre, Nicole M.; Lerman, Dorothea C.; Call, Nathan A.; Addison, Laura R.; Kodak, Tiffany

    2008-01-01

    Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current…

  16. Evaluating the Influence of Postsession Reinforcement on Choice of Reinforcers

    ERIC Educational Resources Information Center

    Kodak, Tiffany; Lerman, Dorothea C.; Call, Nathan

    2007-01-01

    Factors that influence reinforcer choice have been examined in a number of applied studies (e.g., Neef, Mace, Shea, & Shade, 1992; Shore, Iwata, DeLeon, Kahng, & Smith, 1997; Tustin, 1994). However, no applied studies have evaluated the effects of postsession reinforcement on choice between concurrently available reinforcers, even though basic…

  17. Hydraulic Properties of Unsaturated Soils

    USDA-ARS?s Scientific Manuscript database

    Many agrophysical applications require knowledge of the hydraulic properties of unsaturated soils. These properties reflect the ability of a soil to retain or transmit water and its dissolved constituents. The objective of this work was to develop an entry for the Encyclopedia of Agrophysics that w...

  18. Recruiting and retaining indigenous farmworker participants

    PubMed Central

    Farquhar, Stephanie; de Jesus Gonzalez, Carmen; Hall, Jennifer; Samples, Julie; Ventura, Santiago; Sanchez, Valentin; Shadbeh, Nargess

    2013-01-01

    There is limited information on the specific practices used to successfully recruit and retain indigenous and Latino farmworkers in research studies. This article describes the strategies used in a community-based participatory research project with indigenous agricultural workers. Participants were recruited through consulting with indigenous relatives and friends, identifying and meeting with indigenous leaders from hometown associations in countries of origin, and asking current participants to recruit fellow farmworkers. Adjustments were initiated to the second year protocol to enhance recruitment and retention. The difference in attrition rates between years one and two was statistically significant, a difference partially attributed to modifications to recruitment and retention protocol. Findings confirmed that active recruitment techniques and word-of-mouth recruitment were more effective than passive methods. Trust among academic, organization, and community partners, and shared language and culture between those doing the recruitment and the participants, contributed to sustained farmworker participation. PMID:23733354

  19. Transabdominal migration of retained surgical sponge.

    PubMed

    Guner, Ali; Hos, Gultekin; Kahraman, Izzettin; Kece, Can

    2012-01-01

    Retained surgical sponge (RSS) is a rare surgical complication. The RSSs are mostly located intra-abdominally but they can also be left in the thorax, spine, extremity, cranium, and breast. RSS is often difficult to diagnose because of the nonspecific clinical symptoms and radiologic findings. Clinically, RSS may present as an exudative reaction in the early postoperative period or may also cause an aseptic fibrous tissue response. A foreign body may remain asymptomatically silent for a long time, and it may later present with obstruction, fistulization, or mass formation. In this report, we present a case in which an RSS has migrated through the abdominal wall and caused an anterior abdominal wall abscess.

  20. 40 CFR 98.87 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.87 Records that must be retained. (a... § 98.3(g), you must retain the records specified in this paragraph (b) for each portland cement...

  1. 40 CFR 98.87 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.87 Records that must be retained. (a... § 98.3(g), you must retain the records specified in this paragraph (b) for each portland cement...

  2. 40 CFR 98.87 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.87 Records that must be retained. (a... § 98.3(g), you must retain the records specified in this paragraph (b) for each portland cement...

  3. DETAILED VIEW OF MASONRY WORK OF THE RETAINING WALL LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAILED VIEW OF MASONRY WORK OF THE RETAINING WALL LOOKING TO THE SOUTH - Grand Canyon National Park Roads, Village Loop Retaining No. 1, North side of Village Loop Drive, Grand Canyon Village, Coconino County, AZ

  4. DISTANT VIEW OF RETAINING WALL AS SEEN LOOKING TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DISTANT VIEW OF RETAINING WALL AS SEEN LOOKING TO THE SOUTH - Grand Canyon National Park Roads, Village Loop Retaining No. 1, North side of Village Loop Drive, Grand Canyon Village, Coconino County, AZ

  5. Working memory and attentional bias on reinforcing efficacy of food.

    PubMed

    Carr, Katelyn A; Epstein, Leonard H

    2017-09-01

    Reinforcing efficacy of food, or the relationship between food prices and purchasing, is related to obesity status and energy intake in adults. Determining how to allocate resources for food is a decision making process influenced by executive functions. Attention to appetitive cues, as well as working memory capacity, or the ability to flexibly control attention while mentally retaining information, may be important executive functions involved in food purchasing decisions. In two studies, we examined how attention bias to food and working memory capacity are related to reinforcing efficacy of both high energy-dense and low energy-dense foods. The first study examined 48 women of varying body mass index (BMI) and found that the relationship between attentional processes and reinforcing efficacy was moderated by working memory capacity. Those who avoid food cues and had high working memory capacity had the lowest reinforcing efficacy, as compared to those with low working memory capacity. Study 2 systematically replicated the methods of study 1 with assessment of maintained attention in a sample of 48 overweight/obese adults. Results showed the relationship between maintained attention to food cues and reinforcing efficacy was moderated by working memory capacity. Those with a maintained attention to food and high working memory capacity had higher reinforcing efficacy than low working memory capacity individuals. These studies suggest working memory capacity moderated the relationship between different aspects of attention and food reinforcement. Understanding how decision making process are involved in reinforcing efficacy may help to identify future intervention targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Turbomachine blade reinforcement

    SciTech Connect

    Garcia Crespo, Andres Jose

    2016-09-06

    Embodiments of the present disclosure include a system having a turbomachine blade segment including a blade and a mounting segment coupled to the blade, wherein the mounting segment has a plurality of reinforcement pins laterally extending at least partially through a neck of the mounting segment.

  7. Oscillations following periodic reinforcement.

    PubMed

    Monteiro, Tiago; Machado, Armando

    2009-06-01

    Three experiments examined behavior in extinction following periodic reinforcement. During the first phase of Experiment 1, four groups of pigeons were exposed to fixed interval (FI 16s or FI 48s) or variable interval (VI 16s or VI 48s) reinforcement schedules. Next, during the second phase, each session started with reinforcement trials and ended with an extinction segment. Experiment 2 was similar except that the extinction segment was considerably longer. Experiment 3 replaced the FI schedules with a peak procedure, with FI trials interspersed with non-food peak interval (PI) trials that were four times longer. One group of pigeons was exposed to FI 20s PI 80s trials, and another to FI 40s PI 160s trials. Results showed that, during the extinction segment, most pigeons trained with FI schedules, but not with VI schedules, displayed pause-peck oscillations with a period close to, but slightly greater than the FI parameter. These oscillations did not start immediately after the onset of extinction. Comparing the oscillations from Experiments 1 and 2 suggested that the alternation of reconditioning and re-extinction increases the reliability and earlier onset of the oscillations. In Experiment 3 the pigeons exhibited well-defined pause-peck cycles since the onset of extinction. These cycles had periods close to twice the value of the FI and lasted for long intervals of time. We discuss some hypotheses concerning the processes underlying behavioral oscillations following periodic reinforcement.

  8. Self reinforcing polymer composites

    SciTech Connect

    Kenig, S.

    1993-12-31

    In the advent of liquid crystalline polymers (LCPs), self reinforcing polymer composites comprising a polymer matrix and an LCP reinforcement, have become a reality. The so called self reinforcement is due to the LCPs orientability characteristics resulting from their rigid molecular backbone and anisotropy structure in the fluid state. Orientation development takes place during melt processing of the LCP composite blends where shear as well as elongational flows occur prior to consolidation to the solid state. By proper flow control anisotropy develops and in-situ composites are obtained. Polymer composites comprising self-reinforcement by LCPs during processing induced flow, were analyzed and studied with respect to their orientation development and resultant mechanical properties. The analysis commenced with the hydrodynamics of immiscible fluids in shear and elongational flows. Based on the analysis, orientation and morphology development in capillary extrusion was studied, using a variety of thermoplastic polymer matrices like amorphous and crystalline polyamides, polycarbonate and polyester in conjunction of a naphthalene based thermotropic LCP. Based on the flow-morphology relationship the amorphous polyamide/LCP composite was further investigated as it exhibited enhanced properties. Laminated composites based on LCP/amorphous polyamide were developed composed of unidirectional extruded and drawn sheets that were subsequently compression molded. Unidirectional, +45/{minus}45 and quasi-isotropic laminates were prepared and analyzed as to their microstructure and mechanical properties.

  9. Reinforcing Saccadic Amplitude Variability

    ERIC Educational Resources Information Center

    Paeye, Celine; Madelain, Laurent

    2011-01-01

    Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

  10. The Seismic Design of Waterfront Retaining Structures

    DTIC Science & Technology

    1992-11-01

    displacements, submergence, liquefaction potential, and excess pore water pressures, as well as inertial and hydrodynamic forces, are incorporated in the design...backfill. Procedures for incorporating the effects of submergence within the earth pressure computations, including consideration of excess pore water ...computations as specified by one of the following procedures: Restrained water case Free water case - restricted to soils of high permeability (e.g. k > 1 cm

  11. Delayed reinforcement of operant behavior.

    PubMed

    Lattal, Kennon A

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement, but, also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between responses and reinforcers can be isolated from other features of the environment that often accompany delays, such as stimuli or changes in the temporal distribution or rate of reinforcement. The second question is that of the effects of delays on operant behavior. Beyond the common denominator of a temporal separation between reinforcers and the responses that produce them, delay of reinforcement procedures differ from one another along several dimensions, making delay effects circumstance dependent. The final question is one of interpreting delay of reinforcement effects. It centers on the role of the response-reinforcer temporal relation in the context of other, concurrently operating behavioral processes.

  12. DELAYED REINFORCEMENT OF OPERANT BEHAVIOR

    PubMed Central

    Lattal, Kennon A

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement, but, also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between responses and reinforcers can be isolated from other features of the environment that often accompany delays, such as stimuli or changes in the temporal distribution or rate of reinforcement. The second question is that of the effects of delays on operant behavior. Beyond the common denominator of a temporal separation between reinforcers and the responses that produce them, delay of reinforcement procedures differ from one another along several dimensions, making delay effects circumstance dependent. The final question is one of interpreting delay of reinforcement effects. It centers on the role of the response–reinforcer temporal relation in the context of other, concurrently operating behavioral processes. PMID:20676272

  13. Soil in the Anthropocene

    NASA Astrophysics Data System (ADS)

    Richter, Daniel deB; Bacon, Allan R.; Brecheisen, Zachary; Mobley, Megan L.

    2015-07-01

    With scholars deliberating a new name for our geologic epoch, i.e., the Anthropocene, soil scientists whether biologists, chemists, or physicists are documenting significant changes accruing in a majority of Earth's soils. Such global soil changes interact with the atmosphere, biosphere, hydrosphere, and lithosphere (i.e., Earth's Critical Zone), and these developments are significantly impacting the Earth's stratigraphic record as well. In effect, soil scientists study such global soil changes in a science of anthropedology, which leads directly to the need to transform pedostratigraphyinto an anthro-pedostratigraphy, a science that explores how global soil change alters Earth's litho-, bio-, and chemostratigraphy. These developments reinforce perspectives that the planet is indeed crossing into the Anthropocene.

  14. Reinforcing aspects of androgens.

    PubMed

    Wood, Ruth I

    2004-11-15

    Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.

  15. 24 CFR 266.210 - HUD-retained review functions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false HUD-retained review functions. 266.210 Section 266.210 Housing and Urban Development Regulations Relating to Housing and Urban... Program Requirements § 266.210 HUD-retained review functions. Certain functions are retained by the...

  16. 18 CFR 367.2150 - Account 215, Appropriated retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 215, Appropriated retained earnings. 367.2150 Section 367.2150 Conservation of Power and Water Resources FEDERAL... retained earnings. This account must include the amount of retained earnings that has been appropriated or...

  17. 18 CFR 367.2160 - Account 216, Unappropriated retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., Unappropriated retained earnings. 367.2160 Section 367.2160 Conservation of Power and Water Resources FEDERAL... retained earnings. This account must include the balances, either debit or credit, of unappropriated retained earnings arising from earnings of the service company. This account must not include any amounts...

  18. 17 CFR 256.215 - Appropriated retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Appropriated retained earnings... UTILITY HOLDING COMPANY ACT OF 1935 Liabilities and Other Credit Accounts § 256.215 Appropriated retained earnings. This account shall include the amount of retained earnings which has been appropriated or set...

  19. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Retainer and investor depositaries... TREASURY TAX AND LOAN PROGRAM PATAX § 203.16 Retainer and investor depositaries. (a) Credit to TIP main account balance. On the business day that the TSC receives an AOC from a retainer or investor...

  20. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Retainer and investor depositaries... TREASURY TAX AND LOAN PROGRAM PATAX § 203.16 Retainer and investor depositaries. (a) Credit to TIP main account balance. On the business day that the TSC receives an AOC from a retainer or investor...

  1. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Retainer and investor depositaries... TREASURY TAX AND LOAN PROGRAM PATAX § 203.16 Retainer and investor depositaries. (a) Credit to TIP main account balance. On the business day that the TSC receives an AOC from a retainer or investor...

  2. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Retainer and investor depositaries... TREASURY TAX AND LOAN PROGRAM PATAX § 203.16 Retainer and investor depositaries. (a) Credit to TIP main account balance. On the business day that the TSC receives an AOC from a retainer or investor...

  3. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Retainer and investor depositaries... TREASURY TAX AND LOAN PROGRAM PATAX § 203.16 Retainer and investor depositaries. (a) Credit to TIP main account balance. On the business day that the TSC receives an AOC from a retainer or investor...

  4. 24 CFR 266.210 - HUD-retained review functions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false HUD-retained review functions. 266... Program Requirements § 266.210 HUD-retained review functions. Certain functions are retained by the.... Intergovernmental review of Federal programs under Executive Order 12372, as implemented in 24 CFR part 52....

  5. The Reinforcing Event (RE) Menu

    ERIC Educational Resources Information Center

    Addison, Roger M.; Homme, Lloyd E.

    1973-01-01

    A motivational system, the Contingency Management System, uses contracts in which some amount of defined task behavior is demanded for some interval of reinforcing event. The Reinforcing Event Menu, a list of high probability reinforcing behaviors, is used in the system as a prompting device for the learner and as an aid for the administrator in…

  6. Classroom Management and Negative Reinforcement.

    ERIC Educational Resources Information Center

    Tauber, Robert T.

    Of the four simple consequences for behavior, none is more misunderstood than negative reinforcement. A Negative Reinforcement Quiz administered to 233 student teachers from two universities revealed that the vast majority of respondents mistakenly viewed negative reinforcement as a synonym for punishment, and believe that negative reinforcement…

  7. Matching and Conditioned Reinforcement Rate

    ERIC Educational Resources Information Center

    Shahan, Timothy A.; Podlesnik, Christopher A.; Jimenez-Gomez, Corina

    2006-01-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative…

  8. Matching and Conditioned Reinforcement Rate

    ERIC Educational Resources Information Center

    Shahan, Timothy A.; Podlesnik, Christopher A.; Jimenez-Gomez, Corina

    2006-01-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative…

  9. The impact of tropical forest logging and oil palm agriculture on the soil microbiome.

    PubMed

    Tripathi, Binu M; Edwards, David P; Mendes, Lucas William; Kim, Mincheol; Dong, Ke; Kim, Hyoki; Adams, Jonathan M

    2016-05-01

    Selective logging and forest conversion to oil palm agriculture are rapidly altering tropical forests. However, functional responses of the soil microbiome to these land-use changes are poorly understood. Using 16S rRNA gene and shotgun metagenomic sequencing, we compared composition and functional attributes of soil biota between unlogged, once-logged and twice-logged rainforest, and areas converted to oil palm plantations in Sabah, Borneo. Although there was no significant effect of logging history, we found a significant difference between the taxonomic and functional composition of both primary and logged forests and oil palm. Oil palm had greater abundances of genes associated with DNA, RNA, protein metabolism and other core metabolic functions, but conversely, lower abundance of genes associated with secondary metabolism and cell-cell interactions, indicating less importance of antagonism or mutualism in the more oligotrophic oil palm environment. Overall, these results show a striking difference in taxonomic composition and functional gene diversity of soil microorganisms between oil palm and forest, but no significant difference between primary forest and forest areas with differing logging history. This reinforces the view that logged forest retains most features and functions of the original soil community. However, networks based on strong correlations between taxonomy and functions showed that network complexity is unexpectedly increased due to both logging and oil palm agriculture, which suggests a pervasive effect of both land-use changes on the interaction of soil microbes.

  10. Autoshaping Chicks with Heat Reinforcement: The Role of Stimulus-Reinforcer and Response-Reinforcer Relations

    ERIC Educational Resources Information Center

    Wasserman, Edward A.; And Others

    1975-01-01

    The present series of experiments attempted to analyze more fully the contributions of stimulus-reinforcer and response-reinforcer relations to autoshaping within a single conditioning situation. (Author)

  11. Grass plants bind, retain, uptake and transport infectious prions

    PubMed Central

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C.; Hoover, Edward; Soto, Claudio

    2015-01-01

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. PMID:25981035

  12. Grass plants bind, retain, uptake, and transport infectious prions.

    PubMed

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C; Hoover, Edward; Soto, Claudio

    2015-05-26

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrP(Sc)) to plants. Small quantities of PrP(Sc) contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrP(Sc) for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Reinforcement magnitude: an evaluation of preference and reinforcer efficacy.

    PubMed

    Trosclair-Lasserre, Nicole M; Lerman, Dorothea C; Call, Nathan A; Addison, Laura R; Kodak, Tiffany

    2008-01-01

    Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current study was to evaluate the relations among reinforcer magnitude, preference, and efficacy by drawing on the procedures and results of basic experimentation in this area. Three children who engaged in problem behavior that was maintained by social positive reinforcement (attention, access to tangible items) participated. Results indicated that preference for different magnitudes of social reinforcement may predict reinforcer efficacy and that magnitude effects may be mediated by the schedule requirement.

  14. Ethical evaluation of "retainer fee" medical practice.

    PubMed

    Needell, Mervin H; Kenyon, John S

    2005-01-01

    This article examines the reasons that some physicians have recently opted to reduce the size of their practice rosters to allow more time for each patient in exchange for a retainer fee from patients. These physicians also offer supplementary, nonmedical amenities to patients as part of their service. Because physicians have reduced the size of their practice rosters and have increased the price tag for their services, some patients have lost access to their care. We have tried to assess the ethical propriety of such a change in the design of medical practices by weighing plausible, ethically relevant arguments favoring and opposing RFMP. Physicians are ethically obligated first and foremost to promote and protect the health of their patients. RFMP fulfills this duty directly by ensuring prompt and ample professional time for the care of patients. It does so indirectly by allowing time for physicians' continuing education, which in turn should upgrade the quality of care. It also advances the ethical goals of autonomy as it allows patients to choose their own physicians and to spend their money as they please. On the other hand, these ethical positives are offset by the cost of retainer fees that may exclude access of patients to their physicians' care. Even if ethical tradition obligates physicians primarily to patients under their specific care, as professionals and as private citizens, they also have a responsibility to support the health of the entire community. RFMP does little to advance this cause, except that by optimizing the conditions under which their own private patients receive healthcare, they call attention to shortcomings in prevailing public healthcare policies, which by comparison fall short of that standard. An assumption that health is not properly a market commodity, and that all people should receive healthcare on equal terms, would expose RFMP to moral reproof. From an ethical perspective, we find sufficient cause for concern and caution in

  15. Assessment of possibilities and conditions of irrigation in Hungary by digital soil map products

    NASA Astrophysics Data System (ADS)

    Laborczi, Annamária; Bakacsi, Zsófia; Takács, Katalin; Szatmári, Gábor; Szabó, József; Pásztor, László

    2016-04-01

    Sustaining proper soil moisture is essentially important in agricultural management. However, irrigation can be really worth only, if we lay sufficient emphasis on soil conservation. Nationwide planning of irrigation can be taken place, if we have spatially exhaustive maps and recommendations for the different areas. Soil moisture in the pores originate from 'above' (precipitation), or from 'beneath' (from groundwater by capillary lift). The level of groundwater depends on topography, climatic conditions and water regime of the nearby river. The thickness of capillary zone is basicly related to the physical and water management properties of the soil. Accordingly the capillary rise of sandy soils - with very high infiltration rate and very poor water retaining capacity - are far smaller than in the case of clay soils - with very poor infiltration rate and high water retaining capacity. Applying irrigation water can be considered as a reinforcement from 'above', and it affects the salinity and sodicity as well as the soil structure, nutrient supply and soil formation. We defined the possibilities of irrigation according to the average salt content of the soil profile. The nationwide mapping of soil salinity was based on legacy soil profile data, and it was carried out by regression kriging. This method allows that environmental factors with exhaustive spatial extension, such as climatic-, vegetation-, topographic-, soil- and geologic layers can be taken into consideration to the spatial extension of the reference data. According to soil salinity content categories, the areas were delineated as 1. to be irrigated, 2. to be irrigated conditionally, 3. not to be irrigated. The conditions of irrigation was determined by the comparison of the 'actual' and the 'critical' depth of the water table. Since, if the water rises above the critical level, undesirable processes, such as salinization and alkalinization can be developed. The critical depth of the water table was

  16. Dynamic response of flexible retaining walls

    SciTech Connect

    Younan, A.H.; Veletsos, A.S.; Bandyopadhyay, K.

    1997-01-01

    Making use of an extension of a recently proposed, relatively simple, approximate method of analysis, a critical evaluation is made of the response to horizontal ground shaking of flexible walls retaining a uniform, linear, viscoelastic stratum of constant thickness and semiinfinite extent in the horizontal direction. Both cantilever and top-supported walls are examined. Following a detailed description of the method and of its rate of convergence, comprehensive numerical solutions are presented that elucidate the action of the system and the effects of the various parameters involved. The parameters varied include the flexibility of the wall, the condition of top support, and the characteristics of the ground motion. The effects of both harmonic base motions and an actual earthquake record are examined. Special attention is paid to the effects of long-period, effectively static excitations. A maximum dynamic response is then expressed as the product of the corresponding static response and an appropriate amplification or deamplification factor. The response quantities examined include the displacements of the wall relative to the moving base, the dynamic wall pressures, and the total wall force, base shear and base moment.

  17. Behavioral mechanisms underlying nicotine reinforcement.

    PubMed

    Rupprecht, Laura E; Smith, Tracy T; Schassburger, Rachel L; Buffalari, Deanne M; Sved, Alan F; Donny, Eric C

    2015-01-01

    Cigarette smoking is the leading cause of preventable deaths worldwide, and nicotine, the primary psychoactive constituent in tobacco, drives sustained use. The behavioral actions of nicotine are complex and extend well beyond the actions of the drug as a primary reinforcer. Stimuli that are consistently paired with nicotine can, through associative learning, take on reinforcing properties as conditioned stimuli. These conditioned stimuli can then impact the rate and probability of behavior and even function as conditioning reinforcers that maintain behavior in the absence of nicotine. Nicotine can also act as a conditioned stimulus (CS), predicting the delivery of other reinforcers, which may allow nicotine to acquire value as a conditioned reinforcer. These associative effects, establishing non-nicotine stimuli as conditioned stimuli with discriminative stimulus and conditioned reinforcing properties as well as establishing nicotine as a CS, are predicted by basic conditioning principles. However, nicotine can also act non-associatively. Nicotine directly enhances the reinforcing efficacy of other reinforcing stimuli in the environment, an effect that does not require a temporal or predictive relationship between nicotine and either the stimulus or the behavior. Hence, the reinforcing actions of nicotine stem both from the primary reinforcing actions of the drug (and the subsequent associative learning effects) as well as the reinforcement enhancement action of nicotine which is non-associative in nature. Gaining a better understanding of how nicotine impacts behavior will allow for maximally effective tobacco control efforts aimed at reducing the harm associated with tobacco use by reducing and/or treating its addictiveness.

  18. Conditioned reinforcement and response strength.

    PubMed

    Shahan, Timothy A

    2010-03-01

    Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration.

  19. Conditioned Reinforcement and Response Strength

    PubMed Central

    Shahan, Timothy A

    2010-01-01

    Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration. PMID:20885815

  20. Nanostructured composite reinforced material

    DOEpatents

    Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  1. South Oregon Coast Reinforcement.

    SciTech Connect

    United States. Bonneville Power Administration.

    1998-05-01

    The Bonneville Power Administration is proposing to build a transmission line to reinforce electrical service to the southern coast of Oregon. This FYI outlines the proposal, tells how one can learn more, and how one can share ideas and opinions. The project will reinforce Oregon`s south coast area and provide the necessary transmission for Nucor Corporation to build a new steel mill in the Coos Bay/North Bend area. The proposed plant, which would use mostly recycled scrap metal, would produce rolled steel products. The plant would require a large amount of electrical power to run the furnace used in its steel-making process. In addition to the potential steel mill, electrical loads in the south Oregon coast area are expected to continue to grow.

  2. Reinforcement rate and interresponse time differentiation1

    PubMed Central

    Kuch, Dennis O.; Platt, John R.

    1976-01-01

    Reinforcement rate and differential reinforcement of IRTs were independently manipulated to assess their relative contribution to the control of interresponse times (IRTs). Modified percentile reinforcement schedules (Platt, 1973) allowed control of reinforcement rate while longest or shortest IRTs were selectively reinforced. In the absence of differential IRT reinforcement, mean IRT decreased with increasing reinforcement rate. Compared to this small effect of reinforcement rate, reinforcement of long IRTs produced large changes in mean IRT at constant reinforcement rates. No interaction of reinforcement rate and IRT reinforcement was detected. The demonstration of large IRT changes in the absence of reinforcement-rate changes indicates the precedence of IRT reinforcement over molar reinforcement-rate correlations in the determination of IRTs in these procedures. PMID:16811962

  3. A nanostructured carbon-reinforced polyisobutylene-based thermoplastic elastomer.

    PubMed

    Puskas, Judit E; Foreman-Orlowski, Elizabeth A; Lim, Goy Teck; Porosky, Sara E; Evancho-Chapman, Michelle M; Schmidt, Steven P; El Fray, Mirosława; Piatek, Marta; Prowans, Piotr; Lovejoy, Krystal

    2010-03-01

    This paper presents the synthesis and characterization of a polyisobutylene (PIB)-based nanostructured carbon-reinforced thermoplastic elastomer. This thermoplastic elastomer is based on a self-assembling block copolymer having a branched PIB core carrying -OH functional groups at each branch point, flanked by blocks of poly(isobutylene-co-para-methylstyrene). The block copolymer has thermolabile physical crosslinks and can be processed as a plastic, yet retains its rubbery properties at room temperature. The carbon-reinforced thermoplastic elastomer had more than twice the tensile strength of the neat polymer, exceeding the strength of medical grade silicone rubber, while remaining significantly softer. The carbon-reinforced thermoplastic elastomer displayed a high T(g) of 126 degrees C, rendering the material steam-sterilizable. The carbon also acted as a free radical trap, increasing the onset temperature of thermal decomposition in the neat polymer from 256.6 degrees C to 327.7 degrees C. The carbon-reinforced thermoplastic elastomer had the lowest water contact angle at 82 degrees and surface nano-topography. After 180 days of implantation into rabbit soft tissues, the carbon-reinforced thermoplastic elastomer had the thinnest tissue capsule around the microdumbbell specimens, with no eosinophiles present. The material also showed excellent integration into bones. Copyright 2009 Elsevier Ltd. All rights reserved.

  4. Reinforcement learning with Marr.

    PubMed

    Niv, Yael; Langdon, Angela

    2016-10-01

    To many, the poster child for David Marr's famous three levels of scientific inquiry is reinforcement learning-a computational theory of reward optimization, which readily prescribes algorithmic solutions that evidence striking resemblance to signals found in the brain, suggesting a straightforward neural implementation. Here we review questions that remain open at each level of analysis, concluding that the path forward to their resolution calls for inspiration across levels, rather than a focus on mutual constraints.

  5. Reinforcement Learning Trees.

    PubMed

    Zhu, Ruoqing; Zeng, Donglin; Kosorok, Michael R

    In this paper, we introduce a new type of tree-based method, reinforcement learning trees (RLT), which exhibits significantly improved performance over traditional methods such as random forests (Breiman, 2001) under high-dimensional settings. The innovations are three-fold. First, the new method implements reinforcement learning at each selection of a splitting variable during the tree construction processes. By splitting on the variable that brings the greatest future improvement in later splits, rather than choosing the one with largest marginal effect from the immediate split, the constructed tree utilizes the available samples in a more efficient way. Moreover, such an approach enables linear combination cuts at little extra computational cost. Second, we propose a variable muting procedure that progressively eliminates noise variables during the construction of each individual tree. The muting procedure also takes advantage of reinforcement learning and prevents noise variables from being considered in the search for splitting rules, so that towards terminal nodes, where the sample size is small, the splitting rules are still constructed from only strong variables. Last, we investigate asymptotic properties of the proposed method under basic assumptions and discuss rationale in general settings.

  6. Reinforcement Learning Trees

    PubMed Central

    Zhu, Ruoqing; Zeng, Donglin; Kosorok, Michael R.

    2015-01-01

    In this paper, we introduce a new type of tree-based method, reinforcement learning trees (RLT), which exhibits significantly improved performance over traditional methods such as random forests (Breiman, 2001) under high-dimensional settings. The innovations are three-fold. First, the new method implements reinforcement learning at each selection of a splitting variable during the tree construction processes. By splitting on the variable that brings the greatest future improvement in later splits, rather than choosing the one with largest marginal effect from the immediate split, the constructed tree utilizes the available samples in a more efficient way. Moreover, such an approach enables linear combination cuts at little extra computational cost. Second, we propose a variable muting procedure that progressively eliminates noise variables during the construction of each individual tree. The muting procedure also takes advantage of reinforcement learning and prevents noise variables from being considered in the search for splitting rules, so that towards terminal nodes, where the sample size is small, the splitting rules are still constructed from only strong variables. Last, we investigate asymptotic properties of the proposed method under basic assumptions and discuss rationale in general settings. PMID:26903687

  7. Managing pine straw harvests to minimize soil and water losses

    USDA-ARS?s Scientific Manuscript database

    Pine straw is a valuable landscape mulch because it conserves soil moisture, moderates soil temperature, inhibits weed growth, and protects the soil surface against erosion, while retaining a loose structure that allows water, air, and fertilizer to easily reach the soil surface. As a result, marke...

  8. Laboratory study on subgrade soil stabilization using RBI grade 81

    NASA Astrophysics Data System (ADS)

    Cynthia, J. Bernadette; Kamalambikai, B.; Prasanna Kumar, R.; Dharini, K.

    2017-07-01

    The present study investigates the effect of reinforcing the sub grade soils with RBI 81 material. A soil nearby was collected and preliminary tests were conducted to classify the soil and it was found from the results that the sample collected was a poorly graded clay. Subsequently Tests such as Proctor Compaction, CBR, and UCC were conducted to study the various engineering properties of the identified soil. In addition to the above tests were also conducted on the soil by reinforcing with varying percentages of RBI 81. From the analysis of test results it was found that this material (RBI 81) will significantly improve the CBR value of the soil.

  9. Retained fertilizing capability in cryopreserved feline spermatozoa.

    PubMed

    Chatdarong, K

    2017-04-01

    Sperm cryopreservation offers a long-term preservation of male genetic materials for future assisted reproductive technologies. However, dramatic changes in temperature during freezing and thawing injure sperm cells. While motility is essential for AI and membrane integrity is crucial for in vitro fertilization (IVF), sperm DNA integrity is a common index of fertilizing capability required for AI, IVF and intracytoplasmic sperm injection (ICSI). In endangered felids died unexpectedly, attempts have been made to recover as many DNA intact spermatozoa as possible from epididymis and testis to increase the opportunity to produce offspring in future. Although sperm from caudal epididymis has shown retained fertilizing capability after freezing and thawing (27.3% conception rate after unilateral intrauterine insemination), sperm recovery from the corpus epididymis has been suggested as an alternative to increase the amount of preserved genetic materials. To improve epididymal sperm quality, pre-treatment with single-layer centrifugation resulted in selection of sperm cells with intact DNA while post-thaw treatment with extracellular ATP incubation promoted the blastocyst rate. Cold storage of domestic cat testis for 7 days at 4°C demonstrated <1% of sperm cells with fragmented DNA. Moreover, isolated testicular sperm cells, stored for 7 days at 4°C, produced after ICSI poorer percentages of cleavage, morula and blastocyst than the fresh control. In wild felids, a death-to-necropsy time of 2 hr after a jungle cat (Felis chaus) aged 10 years died during anaesthesia plus another necropsy-to-sperm recovery time of 25 hr has been reported to yield the post-thawed testicular sperm with 22.2% intact DNA. In summary, the chromatin structure of feline ejaculated and epididymal sperm seems to be tolerated to cold storage and cryopreservation; thus, fertilizing capability is well protected. In contrast, the cat testicular sperm DNA is generally damaged through the

  10. Fiber reinforced thermoplastic resin matrix composites

    NASA Technical Reports Server (NTRS)

    Jones, Robert J. (Inventor); Chang, Glenn E. C. (Inventor)

    1989-01-01

    Polyimide polymer composites having a combination of enhanced thermal and mechanical properties even when subjected to service temperatures as high as 700.degree. F. are described. They comprise (a) from 10 to 50 parts by weight of a thermoplastic polyimide resin prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and (b) from 90 to 50 parts by weight of continuous reinforcing fibers, the total of (a) and (b) being 100 parts by weight. Composites based on polyimide resin formed from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and pyromellitic dianhydride and continuous carbon fibers retained at least about 50% of their room temperature shear strength after exposure to 700.degree. F. for a period of 16 hours in flowing air. Preferably, the thermoplastic polyimide resin is formed in situ in the composite material by thermal imidization of a corresponding amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. It is also preferred to initially size the continuous reinforcing fibers with up to about one percent by weight of an amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. In this way imidization at a suitable elevated temperature results in the in-situ formation of a substantially homogeneous thermoplastic matrix of the polyimide resin tightly and intimately bonded to the continuous fibers. The resultant composites tend to have optimum thermo-mechanical properties.

  11. Monolithic catalyst catalytic converter with catalyst holding expansible retainer ring

    SciTech Connect

    Isogai, K.; Koga, I.; Ohmori, N.; Okamoto, M.; Takeuchi, M.; Takita, N.; Tobi, N.

    1984-05-15

    A catalytic converter includes a tubular casing within which is held a monolithic catalyst body which is generally of a columnar shape. The ends of the monolithic catalyst body are each engaged with a cushion ring, and each cushion ring is engaged with a retainer ring therefor, which is substantially axially fixed within the casing near to an end thereof. The monolithic catalyst body is supported within the casing by axial compressive force present between the retainer rings on the outside, the cushion rings between the retainer rings, and the monolithic catalyst body between the cushion rings. At least one of the retainer rings is formed with a break in a part of its circumference, the two free ends of the retainer ring on the two sides of the break being movable with distortion of the retainer ring through a certain distance, according to changes of temperature of the retainer ring, with respect to one another in the mutual relative direction which causes the overall circumference of the retainer ring to be diminished, so that expansion of the retainer ring when it heats up is adsorbed, and the retainer ring is not subject to kinking or folding when the catalytic converter operates in the hot condition.

  12. Reinforcement magnitude and responding during treatment with differential reinforcement.

    PubMed Central

    Lerman, Dorothea C; Kelley, Michael E; Vorndran, Christina M; Kuhn, Stephanie A C; LaRue, Robert H

    2002-01-01

    Basic findings indicate that the amount or magnitude of reinforcement can influence free-operant responding prior to and during extinction. In this study, the relation between reinforcement magnitude and adaptive behavior was evaluated with 3 children as part of treatment with differential reinforcement. In the first experiment, a communicative response was shaped and maintained by the same reinforcer that was found to maintain problem behavior. Two reinforcement magnitudes (20-s or 60-s access to toys or escape from demands) were compared and found to be associated with similar levels of resistance to extinction. The relation between reinforcement magnitude and response maintenance was further evaluated in the second experiment by exposing the communicative response to 20-s or 300-s access to toys or escape. Results for 2 participants suggested that this factor may alter the duration of postreinforcement pauses. PMID:11936544

  13. How up- or downslope anchoring affects root reinforcement

    NASA Astrophysics Data System (ADS)

    Giadrossich, Filippo; Schwarz, Massimiliano; Cohen, Denis; Niedda, Marcello

    2016-04-01

    Root reinforcement is important for slope stability. In addition to the important contribution of roots to shear strength along the slip surface, root networks are also recognized to impart stabilization through lateral (parallel to slope) redistribution of forces under tension. The most common method to measure lateral root reinforcement is a pullout test where one root or a bundle of root is pulled out of the soil matrix. This condition represents the case where roots within the mass of a landslide slip out from the upper stable part of the slope. There is also, however, the situation where roots anchored in the upper stable part of the slope slip out from the sliding mass. In the latter it is difficult to quantify root reinforcement and no study has discussed this mechanism. We carried out a new series of laboratory and field experiments using Douglas fir (Pseudotsuga menziesii) roots to quantify how up- or downslope anchoring affects root reinforcement. In addition, we carried out new field pullout tests on coarse roots (larger that 2 mm in diameter, up to 47 mm). Then, considering the state-of-the-art of root reinforcement modeling (the Root Bundle Model), we integrated results from our measurements into the model to verify the magnitude of this effect on overall root reinforcement at the stand scale. Results indicate that the ratio between pullout force and force transferred to the root during soil slip ranges between 0.5 and 1. This indicates that measured pullout force always overestimate the contribution of lateral slipping out roots in situations where the soil slide from anchored roots. This is general the case for root with diameter up to 3-4 mm. Root-size distribution is also a key factor influencing root reinforcement at the forest-stand scale. As most coarse roots break along tension cracks while fine roots slip out, the effect discussed in this study on root reinforcement modeling is negligible when coarse-root diameter classes are represented. Our

  14. Surface Heave Behaviour of Coir Geotextile Reinforced Sand Beds

    NASA Astrophysics Data System (ADS)

    Lal, Dharmesh; Sankar, N.; Chandrakaran, S.

    2017-06-01

    Soil reinforcement by natural fibers is one of the cheapest and attractive ground improvement techniques. Coir is the most abundant natural fiber available in India and due to its high lignin content; it has a larger life span than other natural fibers. It is widely used in India for erosion control purposes, but its use as a reinforcement material is rather limited. This study focuses on the use of coir geotextile as a reinforcement material to reduce surface heave phenomena occurring in shallow foundations. This paper presents the results of laboratory model tests carried out on square footings supported on coir geotextile reinforced sand beds. The influence of various parameters such as depth of reinforcement, length, and number of layers of reinforcement was studied. It was observed that surface heave is considerably reduced with the provision of geotextile. Heave reduction up to 98.7% can be obtained by the proposed method. Heave reduction is quantified by a non-dimensional parameter called heave reduction factor.

  15. Retaining clinician-scientists: nature versus nurture.

    PubMed

    Culican, Susan M; Rupp, Jason D; Margolis, Todd P

    2014-05-27

    career trajectory. To muffle the siren song of private practice and retain those best prepared for the clinician-scientist pathway requires additional investment as their careers mature through protected research time, mentorship, and advocacy.

  16. The nature of sexual reinforcement.

    PubMed Central

    Crawford, L L; Holloway, K S; Domjan, M

    1993-01-01

    Sexual reinforcers are not part of a regulatory system involved in the maintenance of critical metabolic processes, they differ for males and females, they differ as a function of species and mating system, and they show ontogenetic and seasonal changes related to endocrine conditions. Exposure to a member of the opposite sex without copulation can be sufficient for sexual reinforcement. However, copulatory access is a stronger reinforcer, and copulatory opportunity can serve to enhance the reinforcing efficacy of stimulus features of a sexual partner. Conversely, under certain conditions, noncopulatory exposure serves to decrease reinforcer efficacy. Many common learning phenomena such as acquisition, extinction, discrimination learning, second-order conditioning, and latent inhibition have been demonstrated in sexual conditioning. These observations extend the generality of findings obtained with more conventional reinforcers, but the mechanisms of these effects and their gender and species specificity remain to be explored. PMID:8354970

  17. [Reinforcement learning by striatum].

    PubMed

    Kunisato, Yoshihiko; Okada, Go; Okamoto, Yasumasa

    2009-04-01

    Recently, computational models of reinforcement learning have been applied for the analysis of neuroimaging data. It has been clarified that the striatum plays a key role in decision making. We review the reinforcement learning theory and the biological structures such as the brain and signals such as neuromodulators associated with reinforcement learning. We also investigated the function of the striatum and the neurotransmitter serotonin in reward prediction. We first studied the brain mechanisms for reward prediction at different time scales. Our experiment on the striatum showed that the ventroanterior regions are involved in predicting immediate rewards and the dorsoposterior regions are involved in predicting future rewards. Further, we investigated whether serotonin regulates both the reward selection and the striatum function are specialized reward prediction at different time scales. To this end, we regulated the dietary intake of tryptophan, a precursor of serotonin. Our experiment showed that the activity of the ventral part of the striatum was correlated with reward prediction at shorter time scales, and this activity was stronger at low serotonin levels. By contrast, the activity of the dorsal part of the striatum was correlated with reward prediction at longer time scales, and this activity was stronger at high serotonin levels. Further, a higher proportion of small reward choices, together with a higher rate of discounting of delayed rewards is observed in the low-serotonin condition than in the control and high-serotonin conditions. Further examinations are required in future to assess the relation between the disturbance of reward prediction caused by low serotonin and mental disorders related to serotonin such as depression.

  18. In Vitro Assessment of Single-Retainer Tooth-Colored Adhesively Fixed Partial Dentures for Posterior Teeth

    PubMed Central

    Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

    2010-01-01

    The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased. PMID:20652071

  19. In vitro assessment of single-retainer tooth-colored adhesively fixed partial dentures for posterior teeth.

    PubMed

    Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

    2010-01-01

    The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased.

  20. EDTA retention and emissions from remediated soil.

    PubMed

    Jez, Erika; Lestan, Domen

    2016-05-01

    EDTA-based remediation is reaching maturity but little information is available on the state of chelant in remediated soil. EDTA soil retention was examined after extracting 20 soil samples from Pb contaminated areas in Slovenia, Austria, Czech Republic and USA with 120 mM kg(-1) Na2H2EDTA, CaNa2EDTA and H4EDTA for 2 and 24 h. On average, 73% of Pb was removed from acidic and 71% from calcareous soils (24 h extractions). On average, 15% and up to 64% of applied EDTA was after remediation retained in acidic soils. Much less; in average 1% and up to the 22% of EDTA was retained in calcareous soils. The secondary emissions of EDTA retained in selected remediated soil increased with the acidity of the media: the TCLP (Toxicity Characteristic Leaching Procedure) solution (average pH end point 3.6) released up to 36% of EDTA applied in the soil (28.1 mmol kg(-1)). Extraction with deionised water (pH > 6.0) did not produce measurable EDTA emissions. Exposing soil to model abiotic (thawing/freezing cycles) and biotic (ingestion by earthworms Lumbricus rubellus) ageing factors did not induce additional secondary emissions of EDTA retained in remediated soil.

  1. Does retained-seed priming drive the evolution of serotiny in drylands? An assessment using the cactus Mammillaria hernandezii.

    PubMed

    Santini, Bianca A; Martorell, Carlos

    2013-02-01

    Serotinous plants retain their seeds for a long time. In deserts, retained seeds undergo hydration-dehydration cycles and thus may become primed. Priming enhances germination and seedling vigor. We test the hypothesis that serotiny evolves because it provides a site protected from predators in which seeds can become primed. Rainfall-cued dispersal of primed seeds may enhance this effect. We tested this hypothesis with Mammillaria hernandezii through protein-content analyses; field and laboratory germination experiments with primed, unprimed, and retained seeds; and fitness estimations from demographic models. Hydration-dehydration cycles induced priming, enhancing germination. Artificial priming and retention in the parent plant for 1 yr induced similar changes in seed protein patterns, suggesting that priming occurs naturally while seeds are retained. Under field conditions, germination of seeds retained for 1 yr more than doubled that of seeds of the same cohort that were not primed or that remained buried for 1 yr. The first seeds to germinate died rapidly. Serotinous plants whose seeds underwent priming had higher fitness than those whose seeds were in the soil seed bank or that did not experience priming. Priming in soil seed banks may be costly because of high predation, so seed protection during priming is sufficient to promote the evolution of serotiny. Bet hedging contributes to this process. Rapid germination of primed seeds that respond to brief rainfall events is disadvantageous because such rainfall is insufficient for seedling survival. Serotinous species counteract this cost by cueing dispersal with heavy precipitation.

  2. Manifold Regularized Reinforcement Learning.

    PubMed

    Li, Hongliang; Liu, Derong; Wang, Ding

    2017-01-27

    This paper introduces a novel manifold regularized reinforcement learning scheme for continuous Markov decision processes. Smooth feature representations for value function approximation can be automatically learned using the unsupervised manifold regularization method. The learned features are data-driven, and can be adapted to the geometry of the state space. Furthermore, the scheme provides a direct basis representation extension for novel samples during policy learning and control. The performance of the proposed scheme is evaluated on two benchmark control tasks, i.e., the inverted pendulum and the energy storage problem. Simulation results illustrate the concepts of the proposed scheme and show that it can obtain excellent performance.

  3. Laminates and reinforced metals

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1980-01-01

    A selective review is presented of the state of the art of metallic laminates and fiber reinforced metals called metallic matrix laminates (MMLs). Design and analysis procedures that are used for, and typical structural components that have been made from MMLs are emphasized. Selected MMLs, constituent materials, typical material properties and fabrication procedures are briefly described, including hybrids and superhybrids. Advantages, disadvantages, and special considerations required during design, analysis, and fabrication of MMLs are examined. Tabular and graphical data are included to illustrate key aspects of MMLs. Appropriate references are cited to provide a selective bibliography of a rapidly expanding and very promising research and development field.

  4. Fiber reinforced superalloys

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Signorelli, Robert A.; Caulfield, Thomas; Tien, John K.

    1987-01-01

    Improved performance of heat engines is largely dependent upon maximum cycle temperatures. Tungsten fiber reinforced superalloys (TFRS) are the first of a family of high temperature composites that offer the potential for significantly raising hot component operating temperatures and thus leading to improved heat engine performance. This status review of TFRS research emphasizes the promising property data developed to date, the status of TFRS composite airfoil fabrication technology, and the areas requiring more attention to assure their applicability to hot section components of aircraft gas turbine engines.

  5. Memotain: A CAD/CAM nickel-titanium lingual retainer.

    PubMed

    Kravitz, Neal D; Grauer, Dan; Schumacher, Pascal; Jo, Yong-Min

    2017-04-01

    Approximately 1/2 of maxillary and 1/5 of mandibular multi-stranded lingual retainers fail during retention in some form, either bond failure or wire breakage. Memotain is a new CAD/CAM fabricated lingual retainer wire made of custom-cut nickel-titanium, as an alternative to multi-stranded lingual retainers. It offers numerous perceived advantages to the traditional multi-stranded stainless steel wire, including precision fit, avoidance of interferences, corrosion resistance and even the potential for minor tooth movement as an active lingual retainer. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  6. The GP retainer scheme: report of a national survey.

    PubMed

    Lockyer, Lesley; Young, Pat; Main, Paul Gn; Morison, Jim

    2014-11-01

    The current context of organisational change and new working patterns, together with the high cost of medical training, mean it is of vital importance that the NHS retains its trained workforce. The GP retainer scheme supports doctors who for reasons of personal circumstance are restricted in their ability to compete for employment in medicine, and aims to facilitate the retention of their skills and confidence. This national study evaluates the experiences and views of current and past GP retainers and provides a rigorous assessment of the retainer scheme. It is a mixed method study: an online questionnaire was completed by 318 current and ex-retainers across the UK; follow-up telephone interviews were conducted with 30 respondents. The study finds that the GP retainer scheme is effective in retaining GPs through times of transition and provides evidence to support the continuing funding of the scheme across the UK. The scheme is beneficial for doctors who also have a role in caring for young children and is also highly valued by a minority of GP retainers who are using it to return to work after illness, or to practice in a more limited role, due to chronic illness or disability. This study found variations in the implementation of the educational entitlement which is fundamental to the scheme. A minority of retainers experienced problems with the implementation of the scheme and recommendations are made for improvements.

  7. Social Influence as Reinforcement Learning

    DTIC Science & Technology

    2016-01-13

    SECURITY CLASSIFICATION OF: This project examined a reinforcement learning model of conformity and social influence. Under this model, individuals...Oct-2015 Approved for Public Release; Distribution Unlimited Final Report: Social Influence as Reinforcement Learning The views, opinions and/or...Research Triangle Park, NC 27709-2211 W911NF-14-1-0001 - Final Report - Social Influence as Reinforcement Learning REPORT DOCUMENTATION PAGE 11. SPONSOR

  8. [The systems process of reinforcement].

    PubMed

    Sudakov, K V

    1996-01-01

    The process of reinforcement is considered in the context of the general theory of functional systems as an important part of behavioural act organization closely interacting with the dominant motivation. It is shown that reinforcement substantially changes the activities of separate neurons in different brain structures involved in dominant motivation. After a preliminary reinforcement under the influence of corresponding motivation the ribosomal apparatus of neurons begins to synthesize special molecular engrams of the action acceptor. The sensory mechanisms of reinforcement and, especially, the role of emotions are considered in details in the paper.

  9. Quantum reinforcement learning.

    PubMed

    Dong, Daoyi; Chen, Chunlin; Li, Hanxiong; Tarn, Tzyh-Jong

    2008-10-01

    The key approaches for machine learning, particularly learning in unknown probabilistic environments, are new representations and computation mechanisms. In this paper, a novel quantum reinforcement learning (QRL) method is proposed by combining quantum theory and reinforcement learning (RL). Inspired by the state superposition principle and quantum parallelism, a framework of a value-updating algorithm is introduced. The state (action) in traditional RL is identified as the eigen state (eigen action) in QRL. The state (action) set can be represented with a quantum superposition state, and the eigen state (eigen action) can be obtained by randomly observing the simulated quantum state according to the collapse postulate of quantum measurement. The probability of the eigen action is determined by the probability amplitude, which is updated in parallel according to rewards. Some related characteristics of QRL such as convergence, optimality, and balancing between exploration and exploitation are also analyzed, which shows that this approach makes a good tradeoff between exploration and exploitation using the probability amplitude and can speedup learning through the quantum parallelism. To evaluate the performance and practicability of QRL, several simulated experiments are given, and the results demonstrate the effectiveness and superiority of the QRL algorithm for some complex problems. This paper is also an effective exploration on the application of quantum computation to artificial intelligence.

  10. Reoccurrence of retained placenta at vaginal delivery: an observational study.

    PubMed

    Nikolajsen, Sys; Løkkegaard, Ellen Christine Leth; Bergholt, Thomas

    2013-04-01

    To estimate the prevalence and validate the diagnosis of retained placenta in nulliparous women and the risk of reoccurrence at subsequent vaginal delivery. Nested cohort study. Department of Gynecology and Obstetrics, university-affiliated teaching hospital. 10 334 nulliparous singleton pregnancies who delivered vaginally at the hospital during 2000-2009. Data from a computerized database information system were used to identify 287 women who had an ICD-10 diagnosis of retained placenta and 572 randomly selected controls matched by the date of first delivery. At chart review the diagnosis was confirmed by: (1) excessive bleeding <30 minutes after delivery without placental separation, (2) placenta not separated 30 minutes after delivery or (3) confirmation of retained placental tissue >2 hours postpartum. Confirmation of the diagnosis and prevalence of retained placenta. Risk of reoccurrence in a subsequent vaginal delivery. The prevalence of retained placenta increased from 2.8 to 7.0% after confirmation according to the set criteria. Of the selected women, 48.4% had a subsequent vaginal delivery. Of these women, 25.3% (23/91) with a previous retained placenta and 5.3% (11/206) without previously retained placenta, experienced retained placenta in subsequent delivery. This corresponds to an adjusted odds ratio of 5.5 (95% confidence interval 2.6-12.7) in the multivariate analysis for recurrence of retained placenta in a subsequent vaginal delivery. The use of the ICD-10 diagnosis of retained placenta underestimated the prevalence. The risk of reoccurrence of retained placenta is significantly increased in a subsequent vaginal delivery. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica © 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

  11. BEHAVIORAL MECHANISMS UNDERLYING NICOTINE REINFORCEMENT

    PubMed Central

    Rupprecht, Laura E.; Smith, Tracy T.; Schassburger, Rachel L.; Buffalari, Deanne M.; Sved, Alan F.; Donny, Eric C.

    2015-01-01

    Cigarette smoking is the leading cause of preventable deaths worldwide and nicotine, the primary psychoactive constituent in tobacco, drives sustained use. The behavioral actions of nicotine are complex and extend well beyond the actions of the drug as a primary reinforcer. Stimuli that are consistently paired with nicotine can, through associative learning, take on reinforcing properties as conditioned stimuli. These conditioned stimuli can then impact the rate and probability of behavior and even function as conditioning reinforcers that maintain behavior in the absence of nicotine. Nicotine can also act as a conditioned stimulus, predicting the delivery of other reinforcers, which may allow nicotine to acquire value as a conditioned reinforcer. These associative effects, establishing non-nicotine stimuli as conditioned stimuli with discriminative stimulus and conditioned reinforcing properties as well as establishing nicotine as a conditioned stimulus, are predicted by basic conditioning principles. However, nicotine can also act non-associatively. Nicotine directly enhances the reinforcing efficacy of other reinforcing stimuli in the environment, an effect that does not require a temporal or predictive relationship between nicotine and either the stimulus or the behavior. Hence, the reinforcing actions of nicotine stem both from the primary reinforcing actions of the drug (and the subsequent associative learning effects) as well as the reinforcement enhancement action of nicotine which is non-associative in nature. Gaining a better understanding of how nicotine impacts behavior will allow for maximally effective tobacco control efforts aimed at reducing the harm associated with tobacco use by reducing and/or treating its addictiveness. PMID:25638333

  12. 24 CFR 266.210 - HUD-retained review functions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Program Requirements § 266.210 HUD-retained review functions. Certain functions are retained by the Commissioner. The HFA must submit any information or certification required by the Commissioner to permit... participation of the principals of the mortgagor, general contractor, consultant or management agent in...

  13. 17 CFR 256.216 - Unappropriated retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... retained earnings. This account shall include the balance, either debit or credit, arising from earnings... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Unappropriated retained earnings. 256.216 Section 256.216 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION...

  14. 40 CFR 98.257 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.257 Section 98.257 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petroleum Refineries § 98.257 Records that must be retained...

  15. Detail of basaltic rock retaining walls just below top switchback. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of basaltic rock retaining walls just below top switchback. 500 ft long retaining wall at left, scale figure in distance, view south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  16. 50 CFR Table 11 to Part 679 - BSAI Retainable Percentages

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false BSAI Retainable Percentages 11 Table 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Table 11 Table 11 to Part 679—BSAI Retainable Percentages ER31DE08.017 ...

  17. 50 CFR Table 11 to Part 679 - BSAI Retainable Percentages

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false BSAI Retainable Percentages 11 Table 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Table 11 Table 11 to Part 679—BSAI Retainable Percentages ER31DE08.017 ...

  18. 30 CFR 47.55 - Retaining an MSDS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Retaining an MSDS. 47.55 Section 47.55 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR EDUCATION AND TRAINING HAZARD COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must—...

  19. 30 CFR 47.55 - Retaining an MSDS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining an MSDS. 47.55 Section 47.55 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR EDUCATION AND TRAINING HAZARD COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must—...

  20. 30 CFR 47.55 - Retaining an MSDS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Retaining an MSDS. 47.55 Section 47.55 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR EDUCATION AND TRAINING HAZARD COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must—...

  1. 30 CFR 47.55 - Retaining an MSDS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining an MSDS. 47.55 Section 47.55 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR EDUCATION AND TRAINING HAZARD COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must—...

  2. 40 CFR 98.207 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Records that must be retained. 98.207 Section 98.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Magnesium Production § 98.207 Records that must be retained...

  3. 40 CFR 98.207 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Records that must be retained. 98.207 Section 98.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Magnesium Production § 98.207 Records that must be retained...

  4. 40 CFR 98.207 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Records that must be retained. 98.207 Section 98.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Magnesium Production § 98.207 Records that must be retained...

  5. 40 CFR 98.207 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Records that must be retained. 98.207 Section 98.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Magnesium Production § 98.207 Records that must be retained...

  6. Tools for Success in Recruiting and Retaining Hispanic Students

    ERIC Educational Resources Information Center

    Gilroy, Marilyn

    2010-01-01

    In this article, the author talks about strategies for success in recruiting and retaining Hispanic students. One strategy suggested by Raul Lorenzo, account director for Bauza & Associates, a Hispanic marketing agency that helps colleges and universities recruit and retain Hispanic students, is that institutions need to speak to the heart as well…

  7. Tools for Success in Recruiting and Retaining Hispanic Students

    ERIC Educational Resources Information Center

    Gilroy, Marilyn

    2010-01-01

    In this article, the author talks about strategies for success in recruiting and retaining Hispanic students. One strategy suggested by Raul Lorenzo, account director for Bauza & Associates, a Hispanic marketing agency that helps colleges and universities recruit and retain Hispanic students, is that institutions need to speak to the heart as well…

  8. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.147 Section 98.147 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.147 Records that must be retained....

  9. 40 CFR 98.87 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.87 Section 98.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.87 Records that must be retained....

  10. 40 CFR 98.87 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Records that must be retained. 98.87 Section 98.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.87 Records that must be retained....

  11. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.67 Section 98.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained....

  12. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Records that must be retained. 98.67 Section 98.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained....

  13. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Records that must be retained. 98.67 Section 98.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained....

  14. Peri-implant soft tissue maintenance in patients with craniofacial implant retained prostheses.

    PubMed

    Allen, P F; Watson, G; Stassen, L; McMillan, A S

    2000-04-01

    The aim of this pilot study was to describe the effectiveness of a hygiene protocol prescribed for patients receiving craniofacial implant retained prostheses. Eleven subjects receiving either orbital or auricular prostheses were instructed by a hygienist in debris removal procedures. Patients were re-examined on at least four occasions over the following 18 months, and tissue health around the implant abutments was evaluated using standard criteria. In most cases, adequate debris removal was demonstrated, particularly when hygiene procedures were reinforced at the second follow-up visit. Barriers to maintenance of tissue health included inadequate space between fixtures and thickness of skin around abutments. Occasionally, prostheses had to be replaced due to inappropriate cleaning methods. The intensive hygiene regimen helped maintain tissue health around implant abutments, although it was demanding in terms of professional time.

  15. Thermally activated retainer means utilizing shape memory alloy

    NASA Technical Reports Server (NTRS)

    Grimaldi, Margaret E. (Inventor); Hartz, Leslie S. (Inventor)

    1993-01-01

    A retainer member suitable for retaining a gap filler placed in gaps between adjacent tile members is presented. One edge of the retainer member may be attached to the gap filler and another edge may be provided with a plurality of tab members which in an intermediate position do not interfere with placement or removal of the gap filler between tile members. The retainer member may be fabricated from a shape memory alloy which when heated to a specified memory temperature will thermally activate the tab members to predetermined memory positions engaging the tile members to retain the gap filler in the gap. This invention has particular application to the thermal tiles on space vehicles such as the Space Shuttle Orbiter.

  16. Stochastic Reinforcement Benefits Skill Acquisition

    ERIC Educational Resources Information Center

    Dayan, Eran; Averbeck, Bruno B.; Richmond, Barry J.; Cohen, Leonardo G.

    2014-01-01

    Learning complex skills is driven by reinforcement, which facilitates both online within-session gains and retention of the acquired skills. Yet, in ecologically relevant situations, skills are often acquired when mapping between actions and rewarding outcomes is unknown to the learning agent, resulting in reinforcement schedules of a stochastic…

  17. Conditioned Reinforcement and Response Strength

    ERIC Educational Resources Information Center

    Shahan, Timothy A.

    2010-01-01

    Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in…

  18. Be Aware of Negative Reinforcement.

    ERIC Educational Resources Information Center

    Cipani, Ennio C.

    1995-01-01

    This article examines the concept of negative reinforcement in relation to the maintenance of off-task and disruptive behaviors in classrooms. Suggestions are given for determining whether negative reinforcement (in the form of escape from the instructional task) or teacher attention is maintaining the behavior. Suggestions for making tasks less…

  19. Delayed Reinforcement of Operant Behavior

    ERIC Educational Resources Information Center

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  20. Stochastic Reinforcement Benefits Skill Acquisition

    ERIC Educational Resources Information Center

    Dayan, Eran; Averbeck, Bruno B.; Richmond, Barry J.; Cohen, Leonardo G.

    2014-01-01

    Learning complex skills is driven by reinforcement, which facilitates both online within-session gains and retention of the acquired skills. Yet, in ecologically relevant situations, skills are often acquired when mapping between actions and rewarding outcomes is unknown to the learning agent, resulting in reinforcement schedules of a stochastic…

  1. Tangible Reinforcers: Bonuses or Bribes?

    ERIC Educational Resources Information Center

    O'Leary, K. Daniel; And Others

    1972-01-01

    Objections to the use of tangible reinforcers, such as prizes, candy, cigarettes, and money, are discussed. Treatment programs using tangible reinforcers are recommended as powerful modifers of behavior to be implemented only after less powerful means of modification have been tried. (Author)

  2. Reinforcement Learning Through Gradient Descent

    DTIC Science & Technology

    1999-05-14

    Reinforcement learning is often done using parameterized function approximators to store value functions. Algorithms are typically developed for...practice of existing types of algorithms, the gradient descent approach makes it possible to create entirely new classes of reinforcement learning algorithms

  3. Diagnosis And Prescription: Reinforcement Module.

    ERIC Educational Resources Information Center

    Fair, George W.

    This learning module has been designed to aid the teacher trainee in identifying ways in which he influences student behavior in the classroom and also explores means of selecting more meaningful reinforcers and their application. Terminal objectives of the module are the ability to (1) define the terms "reinforcement,""positive…

  4. A systems process of reinforcement.

    PubMed

    Sudakov, K V

    1997-01-01

    Functional systems theory was used to consider the process of reinforcement of the actions on the body of reinforcing factors, i.e., the results of behavior satisfying the body's original needs. The systems process of reinforcement includes reverse afferentation entering the CNS from receptors acted upon by various parameters of the desired results, and mechanisms for comparing reverse afferentation with the apparatus which accepts the results of the action and the corresponding emotional component. A tight interaction between reinforcement and the dominant motivation is generated on the basis of the hologram principle. Reinforcement forms an apparatus for predicting a desired result, i.e. a result-of-action acceptor. Reinforcement procedures significant changes in the activities of individual neurons in the various brain structures involved in dominant motivation, transforming their spike activity for a burst pattern to regular discharges; there are also molecular changes in neuron properties. After preliminary reinforcement, the corresponding motivation induces the ribosomal system of neurons to start synthesizing special effector molecules, which organize molecular engrams of the acceptor of the action's result. Sensory mechanisms of reinforcement are considered, with particular reference to the information role of emotions.

  5. Negative effects of positive reinforcement.

    PubMed

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive-those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say the distinction is untenable). When the distinction is made purely in operational terms, experiments reveal that positive reinforcement has aversive functions. On a practical level, positive reinforcement can lead to deleterious effects, and it is implicated in a range of personal and societal problems. These issues challenge us to identify other criteria for judging behavioral procedures.

  6. Negative effects of positive reinforcement

    PubMed Central

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive—those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say the distinction is untenable). When the distinction is made purely in operational terms, experiments reveal that positive reinforcement has aversive functions. On a practical level, positive reinforcement can lead to deleterious effects, and it is implicated in a range of personal and societal problems. These issues challenge us to identify other criteria for judging behavioral procedures. ImagesFigure 1Figure 2 PMID:22478391

  7. User’s Reference Manual: Computer Program for Design and Analysis of Inverted-T Retaining Walls and Floodwalls (TWDA).

    DTIC Science & Technology

    1980-12-01

    methodology. The analysis procedure considers overturn- ing, sliding, and bearing pressure, relative to the soil immediately adjacent to the wall...equilibrium methods. (e) Limiting value of the overturning stalbi lity resultant ratio . (f) Reinforced concrete design parameters. (g) Specification...combination of Values inside user-defined ranges of base width, bottom of tow elevation, base slope, and key length, for a given stem ratio or toe width

  8. Fracture resistance of direct inlay-retained adhesive bridges: effect of pontic material and occlusal morphology.

    PubMed

    Ozcan, Mutlu; Breuklander, Marijn; Salihoglu-Yener, Esra

    2012-01-01

    This study evaluated the effect of a) pontic materials and b) occlusal morphologies on the fracture resistance of fi ber-reinforced composite (FRC) inlay-retained fixed dental prostheses (FDP). Inlay-retained FRC FPDs (N=45, n=9) were constructed using a) resin composite (deep anatomy), b) natural tooth, c) acrylic denture tooth, d) porcelain denture tooth and e) resin composite (shallow anatomy), as pontic materials. In addition resin composite beams were fabricated (N=30, n=10): i) 'circular', ii) 'elliptic I', and iii) 'elliptic II'. There was no significant difference between the fracture resistance of Groups a, b, c, and d (598, 543, 539, 509 N, respectively) (p>0.05) (One-way ANOVA). Fracture resistance of Group e (1,186 N) was significantly higher than those of other groups (p<0.05) (Tukey's test). No significant difference was found between Group i (1,750 N) and Group ii (1,790 N). Not the pontic material but the occlusal morphology affects the fracture resistance of FRC FDPs.

  9. Human embryonic stem cells passaged using enzymatic methods retain a normal karyotype and express CD30.

    PubMed

    Thomson, Alison; Wojtacha, Davina; Hewitt, Zoë; Priddle, Helen; Sottile, Virginie; Di Domenico, Alex; Fletcher, Judy; Waterfall, Martin; Corrales, Néstor López; Ansell, Ray; McWhir, Jim

    2008-03-01

    Human embryonic stem cells (hESCs) are thought to be susceptible to chromosomal rearrangements as a consequence of single cell dissociation. Compared in this study are two methods of dissociation that do not generate single cell suspensions (collagenase and EDTA) with an enzymatic procedure using trypsin combined with the calcium-specific chelator EGTA (TEG), that does generate a single cell suspension, over 10 passages. Cells passaged by single cell dissociation using TEG retained a normal karyotype. However, cells passaged using EDTA, without trypsin, acquired an isochromosome p7 in three replicates of one experiment. In all of the TEG, collagenase and EDTA-treated cultures, cells retained consistent telomere length and potentiality, demonstrating that single cell dissociation can be used to maintain karyotypically and phenotypically normal hESCs. However, competitive genomic hybridization revealed that subkaryotypic deletions and amplifications could accumulate over time, reinforcing that present culture regimes remain suboptimal. In all cultures the cell surface marker CD30, reportedly expressed on embryonal carcinoma but not karyoptically normal ESCs, was expressed on hESCs with both normal and abnormal karyotype, but was upregulated on the latter.

  10. Is epidural analgesia during labor related to retained placenta?

    PubMed

    Sarit, Avraham; Sokolov, Amit; Many, Ariel

    2016-05-01

    To explore the influence of epidural analgesia on the course of the third stage of labor and on the incidence of the complete retained placenta as well as retained parts of the placenta. This is a population-based cohort study in a tertiary medical center. We collected data from all 4227 spontaneous singleton vaginal deliveries during 6 months and compared the incidence of retained placenta in deliveries with epidural analgesia with those without analgesia. Multivariable logistic regression was used to control for possible confounders. More than two-thirds of the women (69.25%) used epidural analgesia during their delivery. A need for intervention due to placental disorder during the third stage of labor was noted in 4.2% of all deliveries. Epidural analgesia appeared to be significantly (P=0.028) related to placental disorders compared with no analgesia: 4.8% vs. 3%, respectively. Deliveries with manual interventions during the third stage, for either complete retained placenta or suspected retained parts of the placenta, were associated with the use of epidural analgesia (P=0.008), oxytocin (P=0.002) and older age at delivery (P=0.000), but when including all factors in a multivariable analysis, using a stepwise logistic regression, the factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and, marginally, older age. Complete retained placenta and retained parts of the placenta share the same risk factors. Epidural analgesia does not directly influence the incidence of complete retained placenta or retained parts, though clinically linked through increased oxytocin use. The factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and older age.

  11. Lasting impression of violence: Retained bullets and depressive symptoms.

    PubMed

    Smith, Randi N; Seamon, Mark J; Kumar, Vinayak; Robinson, Andrew; Shults, Justine; Reilly, Patrick M; Richmond, Therese S

    2017-09-04

    Over 70,000 nonfatal firearm injuries occur in the US annually, frequently leaving victims injured with retained bullets. The long-term psychological risks associated with retained bullets remains unstudied. By serving as a constant reminder of injury, we hypothesized that the presence of retained bullets after firearm injury is associated with increased PTSD and depression symptom severity. We conducted a prospective cohort study (2013-2015) of Black male survivors of firearm injury at an urban Level I trauma center. Interviews, questionnaires and validated survey tools for PTSD (PCL-5) and depression (QIDS-SR16) to assess severity of symptoms were administered 3 months post-injury. Clinical characteristics and symptom severity scores were compared with respect to retained bullets using Wilcoxon Rank Sum tests and linear regression. Of 139 participants, 101(73%) had retained bullets. The cohort was young (mean age 26 years), educated (82% high school or greater) yet unemployed (53%) and with multiple injuries (median [IQR] no. of GSWs 2 [1-3]). There was no difference in age, education, employment status, number of gunshot wounds, operative procedures, pain, hospital or ICU LOS between groups (p>0.05). Patients with retained bullets less often rated their health as "very good" or "excellent" (10% vs 29%, p=0.046). Of those working prior to injury (n=47), 61% with retained bullets had not returned to work compared to 33% without retained bullets (p=0.027). No difference in PCL-5 scores [30.9 (SD 18.9) vs 27.9 (SD 18.6), p=0.470] was observed, but patients with retained bullets had greater mean QIDS-SR16 scores [10.7 (SD 6.2) vs 7.8 (SD 6.1), p=0.038] than those without. After controlling for injury severity, number of wounds, marital status and education level, multiple linear regression analysis determined that retained bullets (β=3.52; p=0.017) were associated with more severe depressive symptoms. Retained bullets are associated with adverse psychological

  12. Preference pulses induced by reinforcement.

    PubMed

    Hachiga, Yosuke; Sakagami, Takayuki; Silberberg, Alan

    2014-11-01

    Eight rats responded on concurrent Variable-Ratio 20 Extinction schedules for food reinforcement. The assignment of variable-ratio reinforcement to a left or right lever varied randomly following each reinforcer, and was cued by illumination of a stimulus light above that lever. Postreinforcement preference levels decreased substantially and reliably over time when the lever that just delivered reinforcement was now in extinction; however, if that lever was once again associated with variable ratio, this decrease in same-lever preference tended to be small, and for some subjects, not in evidence. The changes in preference level to the extinction lever were well described by a modified version of Killeen, Hanson, and Osborne's (1978) induction model. Consistent with this model's attribution of preference change to induction, we attribute preference change in this report to a brief period of reinforcer-induced arousal that energizes responding to the lever that delivered the last reinforcer. After a few seconds, this induced responding diminishes, and the operant responding that remains comes under the control of the stimulus light cuing the lever providing variable-ratio reinforcement.

  13. Conditioned inhibition and reinforcement rate.

    PubMed

    Harris, Justin A; Kwok, Dorothy W S; Andrew, Benjamin J

    2014-07-01

    We investigated conditioned inhibition in a magazine approach paradigm. Rats were trained on a feature negative discrimination between an auditory conditioned stimulus (CS) reinforced at one rate versus a compound of that CS and a visual stimulus (L) reinforced at a lower rate. This training established L as a conditioned inhibitor. We then tested the inhibitory strength of L by presenting it in compound with other auditory CSs. L reduced responding when tested with a CS that had been reinforced at a high rate, but had less or even no inhibitory effect when tested with a CS that had been reinforced at a low rate. The inhibitory strength of L was greater if it signaled a decrease in reinforcement from an already low rate than if it signaled an equivalent decrease in reinforcement from a high rate. We conclude that the strength of inhibition is not a linear function of the change in reinforcement that it signals. We discuss the implications of this finding for models of learning (e.g., Rescorla & Wagner, 1972) that identify inhibition with a difference (subtraction) rule.

  14. Stimuli, Reinforcers, and Private Events

    PubMed Central

    Nevin, John A

    2008-01-01

    Radical behaviorism considers private events to be a part of ongoing observable behavior and to share the properties of public events. Although private events cannot be measured directly, their roles in overt action can be inferred from mathematical models that relate private responses to external stimuli and reinforcers according to the same quantitative relations that characterize public operant behavior. This approach is illustrated by a model of attending to stimuli and to anticipated reinforcers in delayed matching to sample, in which the probabilities of attending are related to reinforcer rates by an expression derived from research on behavioral momentum. PMID:22478505

  15. Verbal reinforcement combinations in schizophrenics.

    PubMed

    Martin, R B; Moltmann, M L

    1978-10-01

    Investigated the effects of verbal reinforcement paradigms on hospitalized schizophrenics and staff. Positive reinforcement that involved good was found to be relatively ineffective for all groups; furthermore, associating good with the termination of a white noise did not increase its effectiveness for schizophrenics. Verbal punishment was more effective than verbal positive reinforcement for staff, but for schizophrenics only when explicit problem-solving instructions were given. The results suggest that the reduction of deficit is not more likely via verbal punishment; if anything, deficit is increased because of increased staff performance under verbal punishment.

  16. Stimuli, reinforcers, and private events.

    PubMed

    Nevin, John A

    2008-01-01

    Radical behaviorism considers private events to be a part of ongoing observable behavior and to share the properties of public events. Although private events cannot be measured directly, their roles in overt action can be inferred from mathematical models that relate private responses to external stimuli and reinforcers according to the same quantitative relations that characterize public operant behavior. This approach is illustrated by a model of attending to stimuli and to anticipated reinforcers in delayed matching to sample, in which the probabilities of attending are related to reinforcer rates by an expression derived from research on behavioral momentum.

  17. Theory of fiber reinforced materials

    NASA Technical Reports Server (NTRS)

    Hashin, Z.

    1972-01-01

    A unified and rational treatment of the theory of fiber reinforced composite materials is presented. Fundamental geometric and elasticity considerations are throughly covered, and detailed derivations of the effective elastic moduli for these materials are presented. Biaxially reinforced materials which take the form of laminates are then discussed. Based on the fundamentals presented in the first portion of this volume, the theory of fiber-reinforced composite materials is extended to include viscoelastic and thermoelastic properties. Thermal and electrical conduction, electrostatics and magnetostatics behavior of these materials are discussed. Finally, a brief statement of the very difficult subject of physical strength is included.

  18. Micromechanics for particulate reinforced composites

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Goldberg, Robert K.; Mital, Subodh K.

    1996-01-01

    A set of micromechanics equations for the analysis of particulate reinforced composites is developed using the mechanics of materials approach. Simplified equations are used to compute homogenized or equivalent thermal and mechanical properties of particulate reinforced composites in terms of the properties of the constituent materials. The microstress equations are also presented here to decompose the applied stresses on the overall composite to the microstresses in the constituent materials. The properties of a 'generic' particulate composite as well as those of a particle reinforced metal matrix composite are predicted and compared with other theories as well as some experimental data. The micromechanics predictions are in excellent agreement with the measured values.

  19. Fiber-reinforced syntactic foams

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Jen

    Long fibers are generally preferred for reinforcing foams for performance reasons. However, uniform dispersion is difficult to achieve because they must be mixed with liquid resin prior to foam expansion. New approaches aiming to overcome such problem have been developed at USC's Composites Center. Fiber-reinforced syntactic foams with long fibers (over 6 mm in length) manufactured at USC's Composites Center have achieved promising mechanical properties and demonstrated lower density relative to conventional composite foams. Fiber-reinforced syntactic foams were synthesized from thermosetting polymeric microspheres (amino and phenolic microspheres), as well as thermoplastic PVC heat expandable microspheres (HEMs). Carbon and/or aramid fibers were used to reinforce the syntactic foams. Basic mechanical properties, including shear, tensile, and compression, were measured in syntactic foams and fiber-reinforced syntactic foams. Microstructure and crack propagation behavior were investigated by scanning electron microscope and light microscopy. Failure mechanisms and reinforcing mechanisms of fiber-reinforced syntactic foams were also analyzed. As expected, additions of fiber reinforcements to foams enhanced both tensile and shear properties. However, only limited enhancement in compression properties was observed, and fiber reinforcement was of limited benefit in this regard. Therefore, a hybrid foam design was explored and evaluated in an attempt to enhance compression properties. HEMs were blended with glass microspheres to produce hybrid foams, and hybrid foams were subsequently reinforced with continuous aramid fibers to produce fiber-reinforced hybrid foams. Mechanical properties of these foams were evaluated. Findings indicated that the production of hybrid foams was an effective way to enhance the compressive properties of syntactic foams, while the addition of fiber reinforcements enhanced the shear and tensile performance of syntactic foams. Another approach

  20. 132. View of Great Wall of China retaining wall and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    132. View of Great Wall of China retaining wall and unnamed viaduct on Grandfather Mountain. Viaduct completed in 1987. Looking northwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  1. 17. RETAINING WALL CRIBBING AND ROAD VIEW, LOOKING IN SOUTHWARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. RETAINING WALL CRIBBING AND ROAD VIEW, LOOKING IN SOUTHWARD DIRECTION OF TRAVEL BELOW DIAMOND PEAK. ROAD SIGN NOTES SWITCHBACK SEEN IN CA-270-14 TO CA-270-16. LOOKING ESE. - Lassen Park Road, Mineral, Tehama County, CA

  2. 17 CFR 256.215 - Appropriated retained earnings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) UNIFORM SYSTEM OF ACCOUNTS FOR MUTUAL SERVICE COMPANIES AND SUBSIDIARY SERVICE COMPANIES, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935 Liabilities and Other Credit Accounts § 256.215 Appropriated retained...

  3. Recruiting and Retaining Teachers for Richmond Public Schools: Partnership Efforts.

    ERIC Educational Resources Information Center

    Fox, Jill; Alder, Nora; Fitrer, Harold; McLeod, Alan

    2002-01-01

    Describes partnership efforts between the Richmond Public Schools, Virginia, and Virginia Commonwealth University that have focused on the needs of urban schools. Describes challenges that remain with regard to preparing teachers, mentoring beginning teachers, and retaining experienced teachers. (SLD)

  4. 40 CFR 98.427 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of a facility containing production process units must retain quarterly records of captured or transferred CO2 streams and composition. (b) The owner or operator of a CO2 production well facility must...

  5. 40. RETAINING WALL CONSTRUCTION SHOWING PORTION OF COMPLETED WALL. BACKFILLING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. RETAINING WALL CONSTRUCTION SHOWING PORTION OF COMPLETED WALL. BACKFILLING BY POWER SHOVEL IN PROGRESS. ZION NP NEGATIVE NO. 1490. PHOTOGRAPHER: PARKER, NO DATE - Zion-Mount Carmel Highway, Springdale, Washington County, UT

  6. 6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW TO WEST. - Rainbow Hydroelectric Facility, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  7. VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  8. 14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING WALL AT SOUTHERN END OF DAM - Upper Doughty Dam, 200 feet west of Garden State Parkway, 1.7 miles west of Absecon, Egg Harbor City, Atlantic County, NJ

  9. 40 CFR 98.167 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.167 Records that must be retained. In...) through (b) of this section for each hydrogen production facility. (a) If a CEMS is used to measure...

  10. 40 CFR 98.167 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.167 Records that must be retained. In...) through (b) of this section for each hydrogen production facility. (a) If a CEMS is used to measure...

  11. 40 CFR 98.167 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.167 Records that must be retained. In...) through (b) of this section for each hydrogen production facility. (a) If a CEMS is used to measure...

  12. 40 CFR 98.167 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.167 Records that must be retained. In...) through (b) of this section for each hydrogen production facility. (a) If a CEMS is used to measure...

  13. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained. In... aluminum production in metric tons. (b) Type of smelter technology used. (c) The following PFC-specific...

  14. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained. In... aluminum production in metric tons. (b) Type of smelter technology used. (c) The following PFC-specific...

  15. STREET FRONT AND LAVA ROCK RETAINING WALL WITH ENTRY AWNING. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STREET FRONT AND LAVA ROCK RETAINING WALL WITH ENTRY AWNING. VIEW FACING NORTH-NORTHEAST. - U.S. Naval Base, Pearl Harbor, Naval Housing Area Makalapa, Senior Officers' Quarters Type A, 37 Makalapa Drive, Pearl City, Honolulu County, HI

  16. BRICK RETAINING WALL AND STEPS AT FRONT YARD OF CROATAN, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BRICK RETAINING WALL AND STEPS AT FRONT YARD OF CROATAN, VIEW TOWARD GARDEN, FACING NORTHEAST - Overhills, Fort Bragg Military Reservation, Approximately 15 miles NW of Fayetteville, Overhills, Harnett County, NC

  17. 9. Raven's roost overlook detail of the rusticated stone retaining ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Raven's roost overlook detail of the rusticated stone retaining wall/railing and stone curbing. Facing west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  18. RIVER AND ROAD VIEW SHOWING METAL CRIB RETAINING WALLS AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    RIVER AND ROAD VIEW SHOWING METAL CRIB RETAINING WALLS AT RIGHT, FACING SOUTHWEST. PHOTO IS TAKEN FROM SAME POSITION AS PHOTO NO. 84, BUT WITH LONG LENS - Generals Highway, Three Rivers, Tulare County, CA

  19. STONE RETAINING WALL IN CEMETERY CENTER, WITH BIVOUAC OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STONE RETAINING WALL IN CEMETERY CENTER, WITH BIVOUAC OF THE DEAD PLAQUE IN CENTER FOREGROUND. VIEW TO SOUTHEAST. - Fort Mackinac Post Cemetery, Mackinac State Park, Mackinac Island, Mackinac County, MI

  20. 25. VIEW TO EAST; SHOWS CURVE IN SOUTH RETAINING WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. VIEW TO EAST; SHOWS CURVE IN SOUTH RETAINING WALL AND SIDEWALK ELECTROLIER ON ALISO STREET (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  1. 36. VIEW TO NORTH; SOUTH RETAINING WALL AT TRACK LOCATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. VIEW TO NORTH; SOUTH RETAINING WALL AT TRACK LOCATION SHOWING ELECTROLIER (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  2. 19. VIEW TO SOUTHEAST, NORTH SIDE RETAINING WALL; WEST FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW TO SOUTHEAST, NORTH SIDE RETAINING WALL; WEST FRONT MBE BUILDING, FIRST FLOOR (Dobson) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  3. 24. VIEW TO NORTHEAST; OBLIQUE VIEW OF SOUTH RETAINING WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. VIEW TO NORTHEAST; OBLIQUE VIEW OF SOUTH RETAINING WALL AND PARKING STRUCTURE BELOW REA LOADING DOCK (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  4. 9. VIEW TO NORTH; SOUTH RETAINING WALL AND SOUTH FACADE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW TO NORTH; SOUTH RETAINING WALL AND SOUTH FACADE OF MBE BUILDING (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  5. 37. VIEW TO SOUTHEAST; DETAIL, SOUTH RETAINING WALL ELECTROLIER (Asano) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. VIEW TO SOUTHEAST; DETAIL, SOUTH RETAINING WALL ELECTROLIER (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  6. 4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL AND EROSION ON ROAD SURFACE. - Bridalveil Fall Bridge No. 3, Spanning Bridalveil Creek on carriage road, Yosemite Village, Mariposa County, CA

  7. 40 CFR 98.427 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of a facility containing production process units must retain quarterly records of captured or transferred CO2 streams and composition. (b) The owner or operator of a CO2 production well facility...

  8. 40 CFR 98.77 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.77 Records that must be retained... paragraphs (a) and (b) of this section for each ammonia manufacturing unit. (a) If a CEMS is used to measure...

  9. 40 CFR 98.77 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.77 Records that must be retained... paragraphs (a) and (b) of this section for each ammonia manufacturing unit. (a) If a CEMS is used to measure...

  10. Percutaneous Retrieval of a Retained Jackson-Pratt Drain Fragment

    SciTech Connect

    Namyslowski, Jan; Halin, Neil J.; Greenfield, Alan J.

    1996-11-15

    A retained intraabdominal Jackson-Pratt drain fragment was percutaneously retrieved using an inflated angioplasty balloon that had been maneuvered inside of the drain lumen over a hydrophilic-coated steerable guidewire.

  11. 168. Craggy Gardens Visitor Center. View of the rock retaining ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    168. Craggy Gardens Visitor Center. View of the rock retaining wall outside the women's restroom to the northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  12. 40 CFR 98.57 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.57 Records that must be retained... paragraphs (a) through (h) of this section at the facility level: (a) Annual adipic acid production...

  13. 40 CFR 98.387 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Coal-based Liquid Fuels § 98.387 Records that... to the appropriate coal-to-liquid product supplier (e.g., retaining copies of all reports...

  14. 11. EAST VIEW OF RETAINING WALL C ON NORTH SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. EAST VIEW OF RETAINING WALL C ON NORTH SIDE OF EASTBOUND TRAFFIC LANES, EAST OF HAMILTON AVENUE BRIDGE - Davison Freeway from M-10 to Oakland Avenue, Davison Freeway, M-10 to Highland Park, Highland Park, MI

  15. View of main terrace retaining wall with mature tree on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of main terrace retaining wall with mature tree on left center, camera facing southeast - Naval Training Station, Senior Officers' Quarters District, Naval Station Treasure Island, Yerba Buena Island, San Francisco, San Francisco County, CA

  16. 9. VIEW OF SOUTH SIDE OF BRIDGE RETAINING WALL, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF SOUTH SIDE OF BRIDGE RETAINING WALL, SHOWING SMOOTH STEEL REBAR SET IN CONCRETE, LOOKING SOUTH - Box Elder Creek Arch Bridge, Spanning former channel of South fork of Box Elder Creek, Mantua, Box Elder County, UT

  17. 1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM TO LEFT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  18. Elevation of Warrington Avenue Bridge and cut stone retaining wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation of Warrington Avenue Bridge and cut stone retaining wall southbound on Warrington Avenue - Pittsburgh & Castle Shannon Railroad, Warrington Avenue Bridge, Overbrook Trolley Line, Crossing Warrington Avenue, Pittsburgh, Allegheny County, PA

  19. 8. VIEW OF DOWNSTREAM OUTLET CULVERT AND WING RETAINING WALLS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF DOWNSTREAM OUTLET CULVERT AND WING RETAINING WALLS, LOOKING NORTHWEST - High Mountain Dams in Upalco Unit, Twin Pots Dam, Ashley National Forest, 10.1 miles North of Mountain Home, Mountain Home, Duchesne County, UT

  20. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... LOCOMOTIVE ENGINEERS Implementation of the Certification Process § 240.215 Retaining information supporting...) If a railroad relies on the use of a locomotive operations simulator to conduct the...

  1. ELEVATION FROM EAST, SHOWING INTEGRAL RETAINING WALL EXTENDING TO NORTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ELEVATION FROM EAST, SHOWING INTEGRAL RETAINING WALL EXTENDING TO NORTH. - Brick Arch Culvert over Master Street, Spanning dirt slope of Master Street at Thirty-third Street (U.S. Route 13), Philadelphia, Philadelphia County, PA

  2. Function Transformation without Reinforcement

    PubMed Central

    Tonneau, François; Arreola, Fara; Martínez, Alma Gabriela

    2006-01-01

    In studies of function transformation, participants initially are taught to match stimuli in the presence of a contextual cue, X; the stimuli to be matched bear some formal relation to each other, for example, a relation of opposition or difference. In a second phase, the participants are taught to match arbitrary stimuli (say, A and B) in the presence of X. In a final test, A often displays behavioral functions that differ from those of B, and can be predicted from the nature of the relation associated with X in the initial training phase. Here we report function-transformation effects in the absence of selection responses and of their reinforcers. In three experiments with college students, exposure to relations of difference or identity modified the responses given to later stimuli. In Experiment 1, responses to a test stimulus A varied depending on preexposure to pairs of colors that were distinct from A but exemplified relations of difference or identity. In Experiment 2, a stimulus A acquired distinct functions, depending on its previous pairing with a contextual cue X that had itself been paired with identity or difference among colors. Experiment 3 confirmed the results of Experiment 2 with a modified design. Our data are consistent with the notion that relations of identity or difference can serve as stimuli for Pavlovian processes, and, in compound with other cues, produce apparent function-transformation effects. PMID:16776058

  3. Function transformation without reinforcement.

    PubMed

    Tonneau, Franćois; Arreola, Fara; Martínez, Alma Gabriela

    2006-05-01

    In studies of function transformation, participants initially are taught to match stimuli in the presence of a contextual cue, X; the stimuli to be matched bear some formal relation to each other, for example, a relation of opposition or difference. In a second phase, the participants are taught to match arbitrary stimuli (say, A and B) in the presence of X. In a final test, A often displays behavioral functions that differ from those of B, and can be predicted from the nature of the relation associated with X in the initial training phase. Here we report function-transformation effects in the absence of selection responses and of their reinforcers. In three experiments with college students, exposure to relations of difference or identity modified the responses given to later stimuli. In Experiment 1, responses to a test stimulus A varied depending on preexposure to pairs of colors that were distinct from A but exemplified relations of difference or identity. In Experiment 2, a stimulus A acquired distinct functions, depending on its previous pairing with a contextual cue X that had itself been paired with identity or difference among colors. Experiment 3 confirmed the results of Experiment 2 with a modified design. Our data are consistent with the notion that relations of identity or difference can serve as stimuli for Pavlovian processes, and, in compound with other cues, produce apparent function-transformation effects.

  4. Ceramic fiber reinforced filter

    DOEpatents

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  5. Labeled leukocyte scans for detection of retained polyurethane foam

    SciTech Connect

    Ellenberger, P.; Graham, W.P. 3d.; Manders, E.K.; Basarab, R.M.

    1986-01-01

    Complete removal of an infected polyurethane-covered breast prosthesis is difficult, and retained tissue-embedded foam can form a nidus for persistent infection. Scanning the chest wall after administration of indium-111 oxine-labeled autogenous leukocytes will locate areas of infection around retained fragments of foam, thereby facilitating their removal and allowing eventual successful reconstruction. This technique may deserve wider application for locating infected foreign bodies in a variety of patient problems.

  6. Implant retention systems for implant-retained overdentures.

    PubMed

    Laverty, D P; Green, D; Marrison, D; Addy, L; Thomas, M B M

    2017-03-10

    Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

  7. Magnet-Retained Orbital Prosthesis Using a Dental Implant.

    PubMed

    Kim, Soung Min

    2016-12-30

    The loss of an eye and the associated facial disharmony has major physical, psychological, and social consequences for patients undergoing orbital exenteration. A magnet-retained prosthesis with an implant has various advantages over both adhesive and spectacle-retained prostheses for reconstruction of the exenterated orbit.The author demonstrates one representative patient with our orbital reconstruction patients with magnetic implants, which will be applied to various maxillofacial prosthesis strategies in the near future.

  8. Soil warming increases metabolic quotients of soil microorganisms without changes in temperature sensitivity of soil respiration

    NASA Astrophysics Data System (ADS)

    Marañón-Jiménez, Sara; Soong, Jenniffer L.; Leblans, Niki I. W.; Sigurdsson, Bjarni D.; Dauwe, Steven; Fransen, Erik; Janssens, Ivan A.

    2017-04-01

    Increasing temperatures can accelerate soil organic matter (SOM) decomposition and release large amounts of CO2 to the atmosphere, potentially inducing climate change feedbacks. Alterations to the temperature sensitivity and metabolic pathways of soil microorganisms in response to soil warming can play a key role in these soil carbon (C) losses. Here, we present results of an incubation experiment using soils from a geothermal gradient in Iceland that have been subjected to different intensities of soil warming (+0, +1, +3, +5, +10 and +20 °C above ambient) over seven years. We hypothesized that 7 years of soil warming would led to a depletion of labile organic substrates, with a subsequent decrease of the "apparent" temperature sensitivity of soil respiration. Associated to this C limitation and more sub-optimal conditions for microbial growth, we also hypothesized increased microbial metabolic quotients (soil respiration per unit of microbial biomass), which is associated with increases in the relative amount of C invested into catabolic pathways along the warming gradient. Soil respiration and basal respiration rates decreased with soil warming intensity, in parallel with a decline in soil C availability. Contrasting to our first hypothesis, we did not detect changes in the temperature sensitivity of soil respiration with soil warming or on the availability of nutrients and of labile C substrates at the time of incubation. However, in agreement to our second hypothesis, microbial metabolic quotients (soil respiration per unit of microbial biomass) increased at warmer temperatures, while the C retained in biomass decreased as substrate became limiting. Long-term (7 years) temperature increases thus triggered a change in the metabolic functioning of the soil microbial communities towards increasing energy costs for maintenance or resource acquisition, thereby lowering the capacity of C retention and stabilization of warmed soils. These results highlight the need

  9. Geometric Attributes of Retaining Glycosyltransferase Enzymes Favor an Orthogonal Mechanism

    PubMed Central

    Schuman, Brock; Evans, Stephen V.; Fyles, Thomas M.

    2013-01-01

    Retaining glycosyltransferase enzymes retain the stereochemistry of the donor glycosidic linkage after transfer to an acceptor molecule. The mechanism these enzymes utilize to achieve retention of the anomeric stereochemistry has been a matter of much debate. Re-analysis of previously released structural data from retaining and inverting glycosyltransferases allows competing mechanistic proposals to be evaluated. The binding of metal-nucleotide-sugars between inverting and retaining enzymes is conformationally unique and requires the donor substrate to occupy two different orientations in the two types of glycosyltransferases. The available structures of retaining glycosyltransferases lack appropriately positioned enzymatic dipolar residues to initiate or stabilize the intermediates of a dissociative mechanism. Further, available structures show that the acceptor nucleophile and anomeric carbon of the donor sugar are in close proximity. Structural features support orthogonal (front-side) attack from a position lying ≤90° from the C1-O phosphate bond for retaining enzymes. These structural conclusions are consistent with the geometric conclusions of recent kinetic and computational studies. PMID:23936487

  10. The community-reinforcement approach.

    PubMed

    Miller, W R; Meyers, R J; Hiller-Sturmhöfel, S

    1999-01-01

    The community-reinforcement approach (CRA) is an alcoholism treatment approach that aims to achieve abstinence by eliminating positive reinforcement for drinking and enhancing positive reinforcement for sobriety. CRA integrates several treatment components, including building the client's motivation to quit drinking, helping the client initiate sobriety, analyzing the client's drinking pattern, increasing positive reinforcement, learning new coping behaviors, and involving significant others in the recovery process. These components can be adjusted to the individual client's needs to achieve optimal treatment outcome. In addition, treatment outcome can be influenced by factors such as therapist style and initial treatment intensity. Several studies have provided evidence for CRA's effectiveness in achieving abstinence. Furthermore, CRA has been successfully integrated with a variety of other treatment approaches, such as family therapy and motivational interviewing, and has been tested in the treatment of other drug abuse.

  11. Fiber reinforced concrete solar collector

    SciTech Connect

    Slemmons, A. J.; Newgard, P. J.

    1985-05-07

    A solar collector is disclosed comprising a glass member having a solar selective coating thereon, and a molded, glass-reinforced concrete member bonded to the glass member and shaped to provide a series of passageways between the glass member and the fiber-reinforced concrete member capable of carrying heat exchanging fluid therethrough. The fiber-reinforced concrete member may be formed by spraying a thin layer of concrete and chopped fibers such as chopped glass fibers onto a mold to provide an inexpensive and lightweight, thin-walled member. The fiber-reinforced concrete member may have a lightweight cellular concrete backing thereon for insulation purposes. The collector is further characterized by the use of materials which have substantially matching thermal coefficients of expansion over the temperature range normally encountered in the use of solar collectors.

  12. Conditioned reinforcement value and choice.

    PubMed Central

    Preston, R A; Fantino, E

    1991-01-01

    The delay-reduction hypothesis of conditioned reinforcement states that the reinforcing value of a food-associated stimulus is determined by the delay to primary reinforcement signaled by the onset of the stimulus relative to the average delay to primary reinforcement in the conditioning situation. In contrast, most contemporary models of conditioned reinforcement strength posit that the reinforcing strength of a stimulus is some simple function only of the delay to primary reinforcement in the presence of stimulus. The delay-reduction hypothesis diverges from other conditioned reinforcement models in that it predicts that a fixed-duration food-paired stimulus will have different reinforcing values depending on the frequency of its presentation. In Experiment 1, pigeons' key pecks were reinforced according to concurrent-chains schedules with variable-interval 10-second and variable-interval 20-second terminal-link schedules. The initial-link schedule preceding the shorter terminal link was always variable-interval 60 seconds, and the initial-link schedule requirement preceding the longer terminal link was varied between 1 second and 60 seconds across conditions. In Experiment 2, the initial-link schedule preceding the longer of two terminal links was varied for each of three groups of pigeons. The terminal links of the concurrent chains for the three groups were variable-interval 10 seconds and 20 seconds, variable-interval 10 seconds and 30 seconds, and variable-interval 30 seconds and 50 seconds. In both experiments, preference for the shorter terminal link was either a bitonic function or an inverse function of the initial-link schedule preceding the longer terminal-link schedule. Consistent with the predictions of the delay-reduction hypothesis, the relative values of the terminal-link stimuli changed as a function of the overall frequency of primary reinforcement. Vaughan's (1985) melioration model, which was shown to be formally similar to Squires and Fantino

  13. Matching and conditioned reinforcement rate.

    PubMed

    Shahan, Timothy A; Podlesnik, Christopher A; Jimenez-Gomez, Corina

    2006-03-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative conditioned reinforcement rate. In the absence of observing responses, unsignaled periods of food delivery on a variable-interval 90-s schedule alternated with extinction on a center key (i.e., a mixed schedule was in effect). Two concurrently available observing responses produced 15-s access to a stimulus differentially associated with the schedule of food delivery (S+). The relative rate of S+ deliveries arranged by independent variable-interval schedules for the two observing responses varied across conditions. The relation between the ratio of observing responses and the ratio of S+ deliveries was well described by the generalized matching law, despite the absence of changes in the rate of food delivery. In addition, the value of the S+ deliveries likely remained constant across conditions because the ratio of S+ to mixed schedule food deliveries remained constant. Assuming that S+ deliveries serve as conditioned reinforcers, these findings are consistent with the functional similarity between primary and conditioned reinforcers suggested by general choice theories based on the concatenated matching law (e.g., contextual choice and hyperbolic value-added models). These findings are inconsistent with delay reduction theory, which has no terms for the effects of rate of conditioned reinforcement in the absence of changes in rate of primary reinforcement.

  14. Optimization of reinforced concrete slabs

    NASA Technical Reports Server (NTRS)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  15. Optimization of reinforced concrete slabs

    NASA Technical Reports Server (NTRS)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  16. Reinforced ceramics employing discontinuous phases

    SciTech Connect

    Becher, P.F.

    1990-01-01

    The fracture toughness of ceramics can be improved by the incorporation of a variety of discontinuous reinforcing phases and microstructures. Observations of crack paths in these systems indicate that these reinforcing phases bridge the crack tip wake region. Recent developments in micromechanics toughening models applicable to such systems are discussed and compared with experimental observations. Because material parameters and microstructural characteristics are considered, the crack bridging models provide a means to optimize the toughening effects. 18 refs., 2 figs.

  17. Establishing operations and reinforcement effects.

    PubMed

    Vollmer, T R; Iwata, B A

    1991-01-01

    Positive reinforcement procedures have had a major impact on educational programs for the developmentally disabled; nevertheless, variation in reinforcer effectiveness both within and across individuals is a common phenomenon. This study examined one class of variables--establishing operations--that might influence the effectiveness of reinforcers. Five developmentally disabled adult males participated. Responding on one of two motor tasks--switch closure or block placement--was assessed during baseline, satiation, and deprivation conditions with respect to three classes of consequences: small food items, music, and social praise. Deprivation and satiation conditions were constructed so as not to alter significantly the normal course of events in a subject's day. For example, food deprivation entailed scheduling sessions just prior to a subject's regular lunch, and social deprivation involved limiting a subject's access to social interaction for 15 minutes, during which time the subject had access to an assortment of other activities. Results showed that each stimulus class functioned as reinforcement with different degrees of effectiveness during satiation versus deprivation conditions. These results are discussed in light of previous research on enhancement of reinforcer efficacy as well as the assessment and identification of functional reinforcers, and implications are presented for future research and client habilitation.

  18. Reinforcing adherence to antihypertensive medications.

    PubMed

    Petry, Nancy M; Alessi, Sheila M; Byrne, Shannon; White, William B

    2015-01-01

    This pilot study evaluated a reinforcement intervention to improve adherence to antihypertensive therapy. Twenty-nine participants were randomized to standard care or standard care plus financial reinforcement for 12 weeks. Participants in the reinforcement group received a cell phone to self-record videos of adherence, for which they earned rewards. These participants sent videos demonstrating on-time adherence 97.8% of the time. Pill count adherence differed significantly between the groups during treatment, with 98.8%±1.5% of pills taken during treatment in the reinforcement condition vs 92.6%±9.2% in standard care (P<.002). Benefits persisted throughout a 3-month follow-up, with 93.8%±9.3% vs 78.0%±18.5% of pills taken (P<.001). Pill counts correlated significantly (P<.001) with self-reports of adherence, which also differed between groups over time (P<.01). Systolic blood pressure decreased modestly over time in participants overall (P<.01) but without significant time-by-group effects. These results suggest that reinforcing medication adherence via cellular phone technology and financial reinforcement holds potential to improve adherence.

  19. Carbon Nanotubes Reinforced Composites for Biomedical Applications

    PubMed Central

    Wang, Wei; Zhu, Yuhe; Liao, Susan; Li, Jiajia

    2014-01-01

    This review paper reported carbon nanotubes reinforced composites for biomedical applications. Several studies have found enhancement in the mechanical properties of CNTs-based reinforced composites by the addition of CNTs. CNTs reinforced composites have been intensively investigated for many aspects of life, especially being made for biomedical applications. The review introduced fabrication of CNTs reinforced composites (CNTs reinforced metal matrix composites, CNTs reinforced polymer matrix composites, and CNTs reinforced ceramic matrix composites), their mechanical properties, cell experiments in vitro, and biocompatibility tests in vivo. PMID:24707488

  20. Carbon nanotubes reinforced composites for biomedical applications.

    PubMed

    Wang, Wei; Zhu, Yuhe; Liao, Susan; Li, Jiajia

    2014-01-01

    This review paper reported carbon nanotubes reinforced composites for biomedical applications. Several studies have found enhancement in the mechanical properties of CNTs-based reinforced composites by the addition of CNTs. CNTs reinforced composites have been intensively investigated for many aspects of life, especially being made for biomedical applications. The review introduced fabrication of CNTs reinforced composites (CNTs reinforced metal matrix composites, CNTs reinforced polymer matrix composites, and CNTs reinforced ceramic matrix composites), their mechanical properties, cell experiments in vitro, and biocompatibility tests in vivo.

  1. Methods for producing reinforced carbon nanotubes

    DOEpatents

    Ren, Zhifen [Newton, MA; Wen, Jian Guo [Newton, MA; Lao, Jing Y [Chestnut Hill, MA; Li, Wenzhi [Brookline, MA

    2008-10-28

    Methods for producing reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials are disclosed. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  2. Role of Instructions and Reinforcement in Behavior Changes in Token Reinforcement Programs

    ERIC Educational Resources Information Center

    Kazdin, Alan E.

    1973-01-01

    Major findings were that: contingent reinforcement was effective in altering behavior; instructions did not augment the efficacy of contingent reinforcement; noncontingent reinforcement was effective for nondeviant students who were told that the reinforcement was actually contingent; and contingent reinforcement led to greater generalization than…

  3. Role of Instructions and Reinforcement in Behavior Changes in Token Reinforcement Programs

    ERIC Educational Resources Information Center

    Kazdin, Alan E.

    1973-01-01

    Major findings were that: contingent reinforcement was effective in altering behavior; instructions did not augment the efficacy of contingent reinforcement; noncontingent reinforcement was effective for nondeviant students who were told that the reinforcement was actually contingent; and contingent reinforcement led to greater generalization than…

  4. Relationships between soil physicochemical, microbiological properties, and nutrient release in buffer soils compared to field soils.

    PubMed

    Stutter, Marc I; Richards, Samia

    2012-01-01

    The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nutrient retention between buffer and field soils were determined using a combined assay for release of dissolved P, N, and C forms and particulate P. We then explored these differences in relation to changes in soil bulk density (BD), moisture, organic matter by loss on ignition (OM), and altered microbial diversity using molecular fingerprinting (terminal restriction fragment length polymorphism [TRFLP]). Buffer soils had significantly greater soil OM (89% of sites), moisture content (95%), and water-soluble nutrient concentrations for dissolved organic C (80%), dissolved organic N (80%), dissolved organic P (55%), and soluble reactive P (70%). Buffer soils had consistently smaller bulk densities than field soils. Soil fine particle release was generally greater for field than buffer soils. Significantly smaller soil bulk density in buffer soils than in adjacent fields indicated increased porosity and infiltration in buffers. Bacterial, archaeal, and fungal communities showed altered diversity between the buffer and field soils, with significant relationships with soil BD, moisture, OM, and increased solubility of buffer nutrients. Current soil conditions in VBS appear to be leading to potentially enhanced nutrient leaching via increasing solubility of C, N, and P. Manipulating soil microbial conditions (by management of soil moisture, vegetation type, and cover) may provide options for increasing the buffer storage for key nutrients such as P without increasing leaching to adjacent streams.

  5. Reproductive outcomes of retransferring retained embryos in blastocyst transfer cycles.

    PubMed

    Yi, Hyun Jeong; Koo, Hwa Seon; Cha, Sun Hwa; Kim, Hye Ok; Park, Chan Woo; Song, In Ok

    2016-06-01

    To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET. We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population. The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive β-hCG rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) 2,928.4±631.8 vs. 2,948.7±497.8 and the mean gestational age at birth (269.3±17.2 days vs. 264.2±25.7 days). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group. Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters.

  6. Reproductive outcomes of retransferring retained embryos in blastocyst transfer cycles

    PubMed Central

    Yi, Hyun Jeong; Koo, Hwa Seon; Cha, Sun Hwa; Kim, Hye Ok; Park, Chan Woo

    2016-01-01

    Objective To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET. Methods We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population. Results The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive β-hCG rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) 2,928.4±631.8 vs. 2,948.7±497.8 and the mean gestational age at birth (269.3±17.2 days vs. 264.2±25.7 days). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group. Conclusion Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters. PMID:27358833

  7. Implant-retained auricular prostheses: a clinical challenge.

    PubMed

    Arora, V; Sahoo, N K; Gopi, A; Saini, D K

    2016-05-01

    Microtia, malformation, deformity, and partial or complete loss of the pinna may be due to various congenital or acquired factors. In adult patients, surgical reconstruction of the missing pinna is difficult and the results are often far from satisfactory. An implant-retained auricular prosthesis is a suitable alternative. A retrospective study of eight patients treated with implant-retained auricular prostheses was performed. For each missing pinna, three titanium implants were placed in the temporal bone. After 6 months of osseointegration, the implants were loaded. Four cases were rehabilitated with a magnet-retained prosthesis and the remaining four with a bar and clip retained prosthesis. There were six male and two female patients with an average age of 30.62 years. Seven patients had unilateral absence of the pinna and one had bilateral absence. The loss was due to trauma in four patients and to burn in one patient, and three had congenital absence. A total 27 implants were placed, 12 on the right side and 15 on the left. The average post-rehabilitation follow-up was 21 months. Peri-implant tissue reactions were observed at two sites. The implant-retained auricular prosthesis is an alternative treatment approach with good retention and patient satisfaction. Long-term follow-up is required to assess delayed complications.

  8. Seismic analysis for translational failure of landfills with retaining walls.

    PubMed

    Feng, Shi-Jin; Gao, Li-Ya

    2010-11-01

    In the seismic impact zone, seismic force can be a major triggering mechanism for translational failures of landfills. The scope of this paper is to develop a three-part wedge method for seismic analysis of translational failures of landfills with retaining walls. The approximate solution of the factor of safety can be calculated. Unlike previous conventional limit equilibrium methods, the new method is capable of revealing the effects of both the solid waste shear strength and the retaining wall on the translational failures of landfills during earthquake. Parameter studies of the developed method show that the factor of safety decreases with the increase of the seismic coefficient, while it increases quickly with the increase of the minimum friction angle beneath waste mass for various horizontal seismic coefficients. Increasing the minimum friction angle beneath the waste mass appears to be more effective than any other parameters for increasing the factor of safety under the considered condition. Thus, selecting liner materials with higher friction angle will considerably reduce the potential for translational failures of landfills during earthquake. The factor of safety gradually increases with the increase of the height of retaining wall for various horizontal seismic coefficients. A higher retaining wall is beneficial to the seismic stability of the landfill. Simply ignoring the retaining wall will lead to serious underestimation of the factor of safety. Besides, the approximate solution of the yield acceleration coefficient of the landfill is also presented based on the calculated method.

  9. SOSlope 3D: implementing root reinforcement and preferential flow in slope stability modeling

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Cohen, D.

    2013-12-01

    The quantification of root reinforcement represents a key issue in different area of engineering (slope stability, soil protection, silviculture/tree stability, hydraulic). Between all the effects of plants (direct and indirect) on the physical and chemical soil processes, the mechanical effect of roots is considered particularly important for slope stability. The study of root reinforcement is faced with the high complexity of interactions of processes and factors at different spatio-temporal scales. In particular, the hierarchical spatial heterogeneity of vegetation and its effects on soil processes represent a big challenge for quantitative up-scaling methods. The objective of this contribution is to contextualize the complexity of the root-soil interactions in view of slope stability problems, to review the recent scientific contributions in the quantification of root reinforcement, and to discuss the practical meaning of recent research results. In the presentation of an up-scaling framework for the implementation of root reinforcement and preferential flow in slope stability analysis, the following arguments will be discussed: tensile force and pullout force of single roots, apparent elasticity of single roots, strain loading approach for the characterization of root bundle mechanics, meaning of root diameter distribution on root reinforcement, spatial heterogeneity of root distribution, hydro-mechanical and rheological properties of rooted soil under tension and compression, and triggering mechanism of shallow landslides. The above-mentioned factors and processes build up the modules implemented in a numerical model for slope stability calculations, the SOSlope model. The SOSlope model is characterized by the use of a spring-block framework (with 1x1 m cell grid), a strain step loading approach for the redistribution of forces, and the implementation of a spatial distribution of root at the hill slope scale. The results of simulations performed with the

  10. Effect of Reinforcement Architecture on Fracture of Selectively Reinforced Metallic Compact Tension Specimens

    NASA Technical Reports Server (NTRS)

    Abada, Christopher H.; Farley, Gary L.; Hyer, Michael W.

    2006-01-01

    A computer-based parametric study of the effect of reinforcement architectures on fracture response of aluminum compact-tension (CT) specimens is performed. Eleven different reinforcement architectures consisting of rectangular and triangular cross-section reinforcements were evaluated. Reinforced specimens produced between 13 and 28 percent higher fracture load than achieved with the non-reinforced case. Reinforcements with blunt leading edges (rectangular reinforcements) exhibited superior performance relative to the triangular reinforcements with sharp leading edges. Relative to the rectangular reinforcements, the most important architectural feature was reinforcement thickness. At failure, the reinforcements carried between 58 and 85 percent of the load applied to the specimen, suggesting that there is considerable load transfer between the base material and the reinforcement.

  11. Bovine retained placenta: aetiology, pathogenesis and economic loss.

    PubMed

    Laven, R A; Peters, A R

    1996-11-09

    The literature on the effects and causes of retained placenta in the cow is reviewed. On a herd basis the condition can adversely affect milk yield and fertility, but on an individual cow basis the effects are unpredictable. The aetiology of retained placenta has been extensively studied and many causal factors have been implicated, but little is known of how many of them cause the condition. As a result its prevention and prediction is uncertain, primarily because of the lack of knowledge of the normal process of placental release. Vascular changes and uterine contractions play a role in placental release, but current opinion suggests that the primary cause of retained placenta is the retention of the feto-maternal union. Release only occurs after a process of maturation, which involves hormonal and structural changes. The factors which are thought to influence these changes, and thus cause the condition, are discussed.

  12. Retained fetal adrenal cortex in a cynomolgus macaque (Macaca fascicularis).

    PubMed

    Radi, Zaher; Evans, Mark

    2014-10-01

    An incidental, bilateral, retained fetal adrenal cortex was detected in a male cynomolgus macaque (age, approximately 2.4 y) used in a 4-week toxicology study. Microscopic examination of the adrenal gland cortex zone revealed the presence of additional solid sheets and columns of cells supported by vascular capillary bed and composed of large polyhedral cells with abundant eosinophilic, slightly finely vacuolated cytoplasm that surrounded the entire circumference of the medulla. Nuclei were vesicular, round to oval with prominent small nucleoli. There was no evidence for inflammation or cellular degeneration. Based on the microscopic examination, a diagnosis of retained fetal cortex of the adrenal gland was made. This morphologic change resembles fetal cortex in human infants. To our knowledge, this case description is the first report of a cynomolgus macaque with the rare entity of retained fetal cortex, which should not be misinterpreted as a test article-related change. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Follicular Dendritic Cells Retain Infectious HIV in Cycling Endosomes.

    PubMed

    Heesters, Balthasar A; Lindqvist, Madelene; Vagefi, Parsia A; Scully, Eileen P; Schildberg, Frank A; Altfeld, Marcus; Walker, Bruce D; Kaufmann, Daniel E; Carroll, Michael C

    2015-12-01

    Despite the success of antiretroviral therapy (ART), it does not cure Human Immunodeficiency Virus (HIV) and discontinuation results in viral rebound. Follicular dendritic cells (FDC) are in direct contact with CD4+ T cells and they retain intact antigen for prolonged periods. We found that human FDC isolated from patients on ART retain infectious HIV within a non-degradative cycling compartment and transmit infectious virus to uninfected CD4 T cells in vitro. Importantly, treatment of the HIV+ FDC with a soluble complement receptor 2 purges the FDC of HIV virions and prevents viral transmission in vitro. Our results provide an explanation for how FDC can retain infectious HIV for extended periods and suggest a therapeutic strategy to achieve cure in HIV-infected humans.

  14. Retained fetal membranes in the mare: A retrospective study

    PubMed Central

    Provencher, Real; Threlfall, Walter R.; Murdick, Phillip W.; Wearly, W. Keith

    1988-01-01

    A retrospective study of 3456 deliveries was conducted from the records of four Standardbred broodmare farms where mares were bred by artificial insemination and maintained under close veterinary supervision. Retained fetal membranes (RFM) were observed in 10.6% of the deliveries. Retained fetal membranes occurred more frequently (p < 0.05) after dystocia and in mares which had RFM the previous year. Retained fetal membranes after normal foaling had no significant effect on the reproductive performance (pregnancy rate, pregnancy loss rate, or foaling rate), nor on the general health of the mares, regardless of the duration of RFM (3 to 144 hours). Postfoaling laminitis was not observed. Oxytocin therapy of mares with RFM starting at two hours postpartum significantly reduced the incidence of RFM ≥ 8 hours. Mares with RFM which had received intrauterine antimicrobials between foaling and first breeding had a foaling rate similar to mares with RFM which had not received intrauterine therapy. PMID:17423164

  15. Retained surgical sponges, a denied neurosurgical reality? Cautionary note.

    PubMed

    Marquardt, G; Rettig, J; Lang, J; Seifert, V

    2001-03-01

    Surgically acquired foreign bodies are well known but not widely reported. Only seven articles pertaining to this subject were found in the current neurosurgical literature. Are they a denied neurosurgical reality? In this report with a concededly provoking title, the authors elucidate clinical and medicolegal aspects of retained surgical sponges, with emphasis on spinal procedures. To highlight particulars, a case is presented in which a retained surgical sponge was encountered as the cause of progressive low back pain and tender swelling in the scar area after instrumented posterolateral lumbar spinal fusion combined with pedicle screw fixation for lumbosacral spondylolisthesis 4 years earlier. However, until today, no reported neurosurgical patient has suffered a serious complication due to a retained surgical sponge. The authors wish to remind the neurosurgical community to learn from unpleasant clinical and medicolegal experiences in other specialties before serious complications occur, and we suggest rigorous standardization of intraoperative habits to avoid this hazardous complication.

  16. Reinforcement learning and Tourette syndrome.

    PubMed

    Palminteri, Stefano; Pessiglione, Mathias

    2013-01-01

    In this chapter, we report the first experimental explorations of reinforcement learning in Tourette syndrome, realized by our team in the last few years. This report will be preceded by an introduction aimed to provide the reader with the state of the art of the knowledge concerning the neural bases of reinforcement learning at the moment of these studies and the scientific rationale beyond them. In short, reinforcement learning is learning by trial and error to maximize rewards and minimize punishments. This decision-making and learning process implicates the dopaminergic system projecting to the frontal cortex-basal ganglia circuits. A large body of evidence suggests that the dysfunction of the same neural systems is implicated in the pathophysiology of Tourette syndrome. Our results show that Tourette condition, as well as the most common pharmacological treatments (dopamine antagonists), affects reinforcement learning performance in these patients. Specifically, the results suggest a deficit in negative reinforcement learning, possibly underpinned by a functional hyperdopaminergia, which could explain the persistence of tics, despite their evident inadaptive (negative) value. This idea, together with the implications of these results in Tourette therapy and the future perspectives, is discussed in Section 4 of this chapter.

  17. A selectionist approach to reinforcement.

    PubMed Central

    Donahoe, J W; Burgos, J E; Palmer, D C

    1993-01-01

    We describe a principle of reinforcement that draws upon experimental analyses of both behavior and the neurosciences. Some of the implications of this principle for the interpretation of behavior are explored using computer simulations of adaptive neural networks. The simulations indicate that a single reinforcement principle, implemented in a biologically plausible neural network, is competent to produce as its cumulative product networks that can mediate a substantial number of the phenomena generated by respondent and operant contingencies. These include acquisition, extinction, reacquisition, conditioned reinforcement, and stimulus-control phenomena such as blocking and stimulus discrimination. The characteristics of the environment-behavior relations selected by the action of reinforcement on the connectivity of the network are consistent with behavior-analytic formulations: Operants are not elicited but, instead, the network permits them to be guided by the environment. Moreover, the guidance of behavior is context dependent, with the pathways activated by a stimulus determined in part by what other stimuli are acting on the network at that moment. In keeping with a selectionist approach to complexity, the cumulative effects of relatively simple reinforcement processes give promise of simulating the complex behavior of living organisms when acting upon adaptive neural networks. PMID:8354965

  18. Economic and reproductive consequences of retained placenta in dairy cattle.

    PubMed

    Joosten, I; Stelwagen, J; Dijkhuizen, A A

    1988-07-09

    The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    PubMed

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Does supplementary reinforcement of stereotypy facilitate extinction?

    PubMed

    Dozier, Claudia L; Iwata, Brian A; Wilson, David M; Thomason-Sassi, Jessica L; Roscoe, Eileen M

    2013-01-01

    Results of several studies suggest that delivery of supplemental (social) reinforcement for stereotypy might facilitate its subsequent extinction. We examined this possibility with 9 subjects who engaged in stereotypy by including methodological refinements to ensure that (a) subjects' stereotypy was maintained in the absence of social consequences, (b) supplementary reinforcers were highly preferred and were shown to be reinforcers for some behavior, and (c) subjects were exposed to lengthy reinforcement and extinction conditions. In spite of these modifications, only 4 subjects' stereotypy increased when supplementary reinforcement was delivered contingent on stereotypy, and no subject's stereotypy decreased below initial baseline levels when social reinforcement was subsequently withheld. Decreases in stereotypy occurred with the implementation of noncontingent reinforcement. Thus, delivery of supplementary reinforcers either did not increase stereotypy or did not facilitate extinction of stereotypy maintained by automatic reinforcement. We discuss the practical and conceptual bases of these results with respect to our current understanding of function-based interventions.

  1. A review of positive conditioned reinforcement.

    PubMed

    KELLEHER, R T; GOLLUB, L R

    1962-10-01

    This review critically analyzes experimental data relevant to the concept of conditioned reinforcement. The review has five sections. Section I is a discussion of the relationship between primary and conditioned reinforcement in terms of chains of stimuli and responses. Section II is a detailed analysis of the conditions in which the component stimuli in chained schedules of reinforcement will become conditioned reinforcers; this section also analyzes studies of token reinforcement, observing responses, switching responses, implicit chained schedules, and higher-order conditioning. Section III analyzes experiments in which potential conditioned reinforcers are used either to prolong responding or to generate responding during experimental extinction. This section discusses hypotheses that have been offered as alternatives to the concept of conditioned reinforcement and hypotheses concerning the necessary and sufficient conditions for establishing a conditioned reinforcer. Section IV discusses other variables that act when a conditioned reinforcer is being established or that act when an established conditioned reinforcer is used to develop or maintain behavior. Section V is a general discussion of conditioned reinforcement. The evidence indicates that the conditioned reinforcing effectiveness of a stimulus is directly related to the frequency of primary reinforcement occurring in its presence, but is independent of the response rate or response pattern occurring in its presence. Results from chained schedules comprised of several components indicate that a stimulus can be established as a conditioned reinforcer by pairing it with an already established conditioned reinforcer rather than a primary reinforcer; however, this type of higher-order conditioning has not been clearly demonstrated with respondent conditioning procedures. Although discriminative stimuli are usually conditioned reinforcers, the available evidence indicates that establishing a stimulus as a

  2. A Review of Positive Conditioned Reinforcement1

    PubMed Central

    Kelleher, Roger T.; Gollub, Lewis R.

    1962-01-01

    This review critically analyzes experimental data relevant to the concept of conditioned reinforcement. The review has five sections. Section I is a discussion of the relationship between primary and conditioned reinforcement in terms of chains of stimuli and responses. Section II is a detailed analysis of the conditions in which the component stimuli in chained schedules of reinforcement will become conditioned reinforcers; this section also analyzes studies of token reinforcement, observing responses, switching responses, implicit chained schedules, and higher-order conditioning. Section III analyzes experiments in which potential conditioned reinforcers are used either to prolong responding or to generate responding during experimental extinction. This section discusses hypotheses that have been offered as alternatives to the concept of conditioned reinforcement and hypotheses concerning the necessary and sufficient conditions for establishing a conditioned reinforcer. Section IV discusses other variables that act when a conditioned reinforcer is being established or that act when an established conditioned reinforcer is used to develop or maintain behavior. Section V is a general discussion of conditioned reinforcement. The evidence indicates that the conditioned reinforcing effectiveness of a stimulus is directly related to the frequency of primary reinforcement occurring in its presence, but is independent of the response rate or response pattern occurring in its presence. Results from chained schedules comprised of several components indicate that a stimulus can be established as a conditioned reinforcer by pairing it with an already established conditioned reinforcer rather than a primary reinforcer; however, this type of higher-order conditioning has not been clearly demonstrated with respondent conditioning procedures. Although discriminative stimuli are usually conditioned reinforcers, the available evidence indicates that establishing a stimulus as a

  3. A system-wide initiative to prevent retained vaginal sponges.

    PubMed

    Chagolla, Brenda A; Gibbs, Verna C; Keats, John P; Pelletreau, Barbara

    2011-01-01

    As any perinatal nurse knows, retained vaginal sponges are an obstetrical and postpartum patient safety problem. As surgical sponge counts are not routine in some obstetrical units for vaginal births, our healthcare system chose to institute a rigorous process to eliminate retained sponges in all vaginal births. This article describes this process, along with the lessons learned, when Catholic Healthcare West implemented the Sponge ACCOUNTing System in its 32 hospitals in California, Arizona, and Nevada. Implementation of this process involved the standardization of practice for obstetricians, certified nurse midwives, nurses, obstetric technicians, radiologists, and radiology technicians in the management and accounting of surgical sponges.

  4. Uncertainty in retained austenite measurements applied to individual crystallographic orientations

    NASA Astrophysics Data System (ADS)

    Creuziger, A.; Gnäupel-Herold, T.

    2015-04-01

    A technique to measure the phase volume fraction of an individual orientation and the uncertainty in the measurement is demonstrated in this paper. The technique of complete pole figure averaging using neutron diffraction was used to assess the phase fraction of retained austenite in transformation induced plasticity (TRIP) steels and quantify the uncertainty in the phase fraction. In parallel, an ensemble of orientation distribution functions was calculated to assess crystallographic volume fractions of particular orientations and the uncertainty of these volume fractions using Monte Carlo techniques. These methods were combined to measure the retained austenite phase volume fraction of an individual orientation.

  5. 10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN HOUSE AND HILLMAN FAN HOUSE LOOKING EAST The stone retaining wall encloses a pit which may have been the original site of the Hillman Fan House steam engine. The concrete foundations in the left foreground are more recent (c. 1930) additions which may be supports for a porch or stairway. The sloping airshaft, in the middle ground, connected the Baltimore shaft to the New Fan House (not shown) and Hillman Fan House in the background. The Hillman engine house is on the left. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

  6. Bioinspired air-retaining nanofur for drag reduction.

    PubMed

    Kavalenka, Maryna N; Vüllers, Felix; Lischker, Simone; Zeiger, Claudia; Hopf, Andreas; Röhrig, Michael; Rapp, Bastian E; Worgull, Matthias; Hölscher, Hendrik

    2015-05-27

    Bioinspired nanofur, covered by a dense layer of randomly distributed high aspect ratio nano- and microhairs, possesses superhydrophobic and air-retaining properties. Nanofur is fabricated using a highly scalable hot pulling method in which softened polymer is elongated with a heated sandblasted plate. Here we investigate the stability of the underwater air layer retained by the irregular nanofur topography by applying hydraulic pressure to the nanofur kept underwater, and evaluate the gradual changes in the air-covered area. Furthermore, the drag reduction resulting from the nanofur air retention is characterized by measuring the pressure drop across channels with and without nanofur.

  7. Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane

    PubMed Central

    Alharbi, Saad S.; Asiri, Mohammed S.

    2016-01-01

    A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO) following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation. PMID:27555718

  8. Analysing hydro-mechanical behaviour of reinforced slopes through centrifuge modelling

    NASA Astrophysics Data System (ADS)

    Veenhof, Rick; Wu, Wei

    2017-04-01

    Every year, slope instability is causing casualties and damage to properties and the environment. The behaviour of slopes during and after these kind of events is complex and depends on meteorological conditions, slope geometry, hydro-mechanical soil properties, boundary conditions and the initial state of the soils. This study describes the effects of adding reinforcement, consisting of randomly distributed polyolefin monofilament fibres or Ryegrass (Lolium), on the behaviour of medium-fine sand in loose and medium dense conditions. Direct shear tests were performed on sand specimens with different void ratios, water content and fibre or root density, respectively. To simulate the stress state of real scale field situations, centrifuge model tests were conducted on sand specimens with different slope angles, thickness of the reinforced layer, fibre density, void ratio and water content. An increase in peak shear strength is observed in all reinforced cases. Centrifuge tests show that for slopes that are reinforced the period until failure is extended. The location of shear band formation and patch displacement behaviour indicate that the design of slope reinforcement has a significant effect on the failure behaviour. Future research will focus on the effect of plant water uptake on soil cohesion.

  9. Resurgence and alternative-reinforcer magnitude.

    PubMed

    Craig, Andrew R; Browning, Kaitlyn O; Nall, Rusty W; Marshall, Ciara M; Shahan, Timothy A

    2017-03-01

    Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative-reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single-pellet reinforcers during Phase 1. In Phase 2, target-lever pressing was extinguished, and alternative-lever pressing produced either five-pellet, one-pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five-pellet alternative reinforcement produced faster elimination and greater resurgence of target-lever pressing than one-pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative-reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six-pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six-pellet to one-pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative-reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative-reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative-reinforcement source.

  10. Response acquisition with delayed reinforcement.

    PubMed

    Lattal, K A; Gleeson, S

    1990-01-01

    Discrete responses of experimentally naive, food-deprived White Carneaux pigeons (key pecks) or Sprague-Dawley rats (bar or omnidirectional lever presses) initiated unsignaled delay periods that terminated with food delivery. Each subject first was trained to eat from the food source, but no attempt was made to shape or to otherwise train the response. In both species, the response developed and was maintained. Control procedures excluded the simple passage of time, response elicitation or induction by food presentation, type of operandum, food delivery device location, and adventitious immediate reinforcement of responding as the basis for the effects. Results revealed that neither training nor immediate reinforcement is necessary to establish new behavior. The conditions that give rise to both the first and second response are discussed, and the results are related to other studies of the delay of reinforcement and to explanations of behavior based on contingency or correlation and contiguity.

  11. Strong fiber-reinforced hydrogel.

    PubMed

    Agrawal, Animesh; Rahbar, Nima; Calvert, Paul D

    2013-02-01

    In biological hydrogels, the gel matrix is usually reinforced with micro- or nanofibers, and the resulting composite is tough and strong. In contrast, synthetic hydrogels are weak and brittle, although they are highly elastic. The are many potential applications for strong synthetic hydrogels in medical devices, including as scaffolds for tissue growth. This work describes a new class of hydrogel composites reinforced with elastic fibers, giving them a cartilage-like structure. A three-dimensional rapid prototyping technique was used to form crossed "log-piles" of elastic fibers that are then impregnated with an epoxy-based hydrogel in order to form the fiber-reinforced gel. The fibrous construct improves the strength, modulus and toughness of the hydrogel, and also constrains the swelling. By altering the construct geometry and studying the effect on mechanical properties, we will develop the understanding needed to design strong hydrogels for biomedical devices and soft machines. Copyright © 2012. Published by Elsevier Ltd.

  12. Forest soils

    Treesearch

    Charles H. (Hobie) Perry; Michael C. Amacher

    2009-01-01

    Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

  13. Circuit organization of sugar reinforcement.

    PubMed

    de Araujo, Ivan E

    2016-10-01

    Sugar's potent reinforcing properties arise from the complex interplay between gustatory and nutritive signals. This commentary addresses a unique organizational aspect of the neuronal circuitry that mediates sugar reinforcement in both Drosophila and rodents. Specifically, current evidence supports a general circuit model where separate populations of dopaminergic neurons encode the gustatory and nutritive values of sugar. This arrangement allows animals to prioritize energy seeking over taste quality, and implies that specialized subpopulations of dopamine-containing neurons form a class of evolutionary conserved chemo- and nutrient-sensors. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Novel Methods for Reinforcing Elastomers

    DTIC Science & Technology

    1989-04-05

    elastomer bonding was not as strong as that observed in the case of silica. Zeolites , simply blended into poly(dimethylsiloxane), gave surprisingly good...Used to Reinforce an Elastomer, G. S. Sur and J. E. Mark, Polvm. Bulletin, 20, 131 (1988). -2-,,)flC-’ Avalaebility Codes COW - Av Ii and/or t4 spcla...Wang, Plvm. Bullen. 20, 443 (1988). 13. Zeolites as Reinforcing Fillers in an Elastomer, A. M. S. Al-ghamdi and J. E. Mark, Polm. Bulltin, 20, 537

  15. Special Education and Reinforcement Theory: Are we Reinforcing Deficient Behavior?

    ERIC Educational Resources Information Center

    Stoppleworth, Leland J.

    1974-01-01

    The consequences that follow behavioral performance play an important part in operant learning theory. This article asks if special educational practice take into consideration the possibility that the performance of deficient behavior may, in fact, have reinforcing consequences for some handicapped individuals. (Author)

  16. Reinforcer Accumulation in a Token-Reinforcement Context with Pigeons

    ERIC Educational Resources Information Center

    Yankelevitz, Rachelle L.; Bullock, Christopher E.; Hackenberg, Timothy D.

    2008-01-01

    Four pigeons were exposed to a token-reinforcement procedure with stimulus lights serving as tokens. Responses on one key (the token-production key) produced tokens that could be exchanged for food during an exchange period. Exchange periods could be produced by satisfying a ratio requirement on a second key (the exchange-production key). The…

  17. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Records that must be retained. 98.347 Section 98.347 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.347 Records that must...

  18. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Records that must be retained. 98.347 Section 98.347 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.347 Records that must...

  19. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Records that must be retained. 98.347 Section 98.347 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.347 Records that must...

  20. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Records that must be retained. 98.347 Section 98.347 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.347 Records that must...

  1. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.347 Section 98.347 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.347 Records that must...

  2. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.147 Records that must be retained. In... paragraphs (a)(1) and (a)(2) of this section: (1) Monthly glass production rate for each continuous glass... glass melting furnace (tons). (b) If process CO2 emissions are calculated according to the procedures...

  3. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.147 Records that must be retained. In... paragraphs (a)(1) and (a)(2) of this section: (1) Monthly glass production rate for each continuous glass... glass melting furnace (tons). (b) If process CO2 emissions are calculated according to the procedures...

  4. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.147 Records that must be retained. In... paragraphs (a)(1) and (a)(2) of this section: (1) Monthly glass production rate for each continuous glass... glass melting furnace (tons). (b) If process CO2 emissions are calculated according to the procedures...

  5. 40 CFR 98.447 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Records that must be retained. 98.447 Section 98.447 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Geologic Sequestration of Carbon Dioxide § 98.447 Records that...

  6. 40 CFR 98.447 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Records that must be retained. 98.447 Section 98.447 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Geologic Sequestration of Carbon Dioxide § 98.447 Records that...

  7. 40 CFR 98.337 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.337 Records that must be retained. In...) through (b) of this section for each zinc production facility. (a) If a CEMS is used to measure emissions... each zinc product (tons). (2) Annual operating hours for all Waelz kilns and electrothermic furnaces...

  8. 40 CFR 98.337 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.337 Records that must be retained. In...) through (b) of this section for each zinc production facility. (a) If a CEMS is used to measure emissions... each zinc product (tons). (2) Annual operating hours for all Waelz kilns and electrothermic furnaces...

  9. 40 CFR 98.337 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.337 Records that must be retained. In...) through (b) of this section for each zinc production facility. (a) If a CEMS is used to measure emissions... each zinc product (tons). (2) Annual operating hours for all Waelz kilns and electrothermic furnaces...

  10. 40 CFR 98.337 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.337 Records that must be retained. In...) through (b) of this section for each zinc production facility. (a) If a CEMS is used to measure emissions... each zinc product (tons). (2) Annual operating hours for all Waelz kilns and electrothermic furnaces...

  11. A Market-Driven Approach to Retaining Talent.

    ERIC Educational Resources Information Center

    Cappelli, Peter

    2000-01-01

    Employee retention must be rethought in a free-agent market. Compensation can shape who leaves and stays. Job design and customization can tailor jobs to employee needs. Encouraging social ties among colleagues and selecting appealing locations for workplaces are other ways to retain talented workers. (SK)

  12. Recruiting and Retaining Physicians in Very Rural Areas

    ERIC Educational Resources Information Center

    Pepper, Carolyn M.; Sandefer, Ryan H.; Gray, Matt J.

    2010-01-01

    Context: Recruiting and retaining physicians is a challenge in rural areas. Growing up in a rural area and completing medical training in a rural area have been shown to predict decisions to practice in rural areas. Little is known, though, about factors that contribute to physicians' decisions to locate in very sparsely populated areas. Purpose:…

  13. 40 CFR 98.47 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Records that must be retained. 98.47 Section 98.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.47 Records that must be...

  14. 40 CFR 98.47 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Records that must be retained. 98.47 Section 98.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.47 Records that must be...

  15. A Market-Driven Approach to Retaining Talent.

    ERIC Educational Resources Information Center

    Cappelli, Peter

    2000-01-01

    Employee retention must be rethought in a free-agent market. Compensation can shape who leaves and stays. Job design and customization can tailor jobs to employee needs. Encouraging social ties among colleagues and selecting appealing locations for workplaces are other ways to retain talented workers. (SK)

  16. Hiring & Retaining More Women: The Advantages to Law Enforcement Agencies.

    ERIC Educational Resources Information Center

    Lonsway, Kimberly A.

    Hiring and retaining more women provides numerous important advantages to law enforcement agencies. Research conducted in the United States and internationally has clearly documented that following facts: (1) female officers are as competent as their male counterparts and even excel in certain areas of police performance; (2) female officers are…

  17. 24 CFR 266.210 - HUD-retained review functions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Subsidy layering. The Commissioner, or Housing Credit Agencies through such delegation as may be in effect... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false HUD-retained review functions. 266.210 Section 266.210 Housing and Urban Development Regulations Relating to Housing and Urban...

  18. 40 CFR 98.277 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Records that must be retained. 98.277 Section 98.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Pulp and Paper Manufacturing § 98.277 Records that must...

  19. 40 CFR 98.297 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Soda Ash Manufacturing § 98.297 Records that must be retained... (a) and (b) of this section for each soda ash manufacturing line. (a) If a CEMS is used to measure... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual...

  20. 40 CFR 98.297 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Soda Ash Manufacturing § 98.297 Records that must be retained... (a) and (b) of this section for each soda ash manufacturing line. (a) If a CEMS is used to measure... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual...

  1. Six Types of Teachers: Recruiting, Retaining and Mentoring the Best

    ERIC Educational Resources Information Center

    Fiore, Douglas J.; Whitaker, Todd

    2004-01-01

    This book helps principals and all others who hire and retain teachers to sharpen their ability to hire better teachers for their schools, improve the ones who are already there, and keep their best and brightest on board. It demonstrates that the quality of the people on staff will ultimately determine the quality of the school and the success of…

  2. Retaining Students in Grade: Consequences for Florida. Policy Brief.

    ERIC Educational Resources Information Center

    Smith, Mary Lee

    2004-01-01

    Eliminating social promotion, retaining students in grade, and using proficiency standards to determine students' progress through grades was intended to make schools accountable and increase academic achievement. Research evidence demonstrates that grade retention does not improve achievement and may increase the chances of a student dropping out…

  3. Attracting and Retaining Teachers: A Question of Motivation

    ERIC Educational Resources Information Center

    Muller, Karin; Alliata, Roberta; Benninghoff, Fabienne

    2009-01-01

    Attracting and retaining competent teachers is a key concern when it comes to managing the supply and demand for teachers. This article examines the motivation that prompts people to enter or leave the teaching profession with the aim of identifying a decision framework for defining teacher policies. The results are based on the teacher workforce…

  4. Attracting and Retaining High-Quality Professionals in Science Education.

    ERIC Educational Resources Information Center

    Weld, Jeffrey

    1998-01-01

    To attract and retain high-quality teachers, the education system must address science teachers' sense of professional isolation, administrators' lack of receptivity to thoughtful teachers' ideas, egalitarian salary compensation schemes, and lack of professional recognition. An outstanding chemistry teacher-turned-pharmaceutical saleswoman is…

  5. Good Laboratory Practice. Part 2. Recording and Retaining Raw Data

    ERIC Educational Resources Information Center

    Wedlich, Richard C.; Libera, Agata E.; Pires, Amanda; Tellarini, Cassandra

    2013-01-01

    A clear understanding of how "raw data" is defined, recorded, and retained in the laboratory record is essential to the chemist employed in the laboratory compliant with the Good Laboratory Practices regulations. This article is intended to provide an understanding by drawing upon examples taken from the modern pharmaceutical analysis…

  6. 14 CFR 330.35 - What records must carriers retain?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in making the forecasts. (4) You must agree to have your independent public accountant retain all... conducted by your independent public accountant under the requirements of this part for a period of five years. The accountant must make this information available for audit and examination by...

  7. 9. PHOTO LOOKING SOUTH FROM THE RETAINING WALL ON THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. PHOTO LOOKING SOUTH FROM THE RETAINING WALL ON THE NORTH ABUTMENT REVEALS THE SOUTHEAST ABUTMENT. DETAILS OF THE CONCRETE WORK ON THE BALUSTRADE ARE ALSO VISIBLE - Delphi Bridge on U.S. Route 421, Spanning Deer Creek at U.S. Route 421, Delphi, Carroll County, IN

  8. 9. VIEW OF ROCK SLIDE AND STONE RETAINING WALL ALONG ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF ROCK SLIDE AND STONE RETAINING WALL ALONG THE RAILROAD GRADE ABOUT 3/4 MILE SOUTHWEST OF VIVIAN PARK, LOOKING SOUTHWEST - Heber Creeper Railroad Line, Section from Bridal Veil Falls to Vivian Park, Between Provo & Heber City, Provo, Utah County, UT

  9. Evaluating the Need for Counseling Intervention for Retained Elementary Students

    ERIC Educational Resources Information Center

    Landrum, Diedra

    2008-01-01

    Evaluating the Need for Counseling Intervention for Retained Elementary Students. Landrum, Diedra, 2007: Applied Dissertation, Nova Southeastern University, Fischler School of Education and Human Services. Elementary School Counseling/School Counseling/Grade Repetition/Counselor Teacher Cooperation/Parent School Relationship. This applied…

  10. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; (3) Any relevant data furnished by a governmental agency concerning the person's motor vehicle... administered. (e) The information concerning demonstrated performance skills that the railroad shall retain... the performance skills test(s) that documents the relevant operating facts on which the evaluation is...

  11. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; (3) Any relevant data furnished by a governmental agency concerning the person's motor vehicle... administered. (e) The information concerning demonstrated performance skills that the railroad shall retain... the performance skills test(s) that documents the relevant operating facts on which the evaluation is...

  12. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; (3) Any relevant data furnished by a governmental agency concerning the person's motor vehicle... administered. (e) The information concerning demonstrated performance skills that the railroad shall retain... the performance skills test(s) that documents the relevant operating facts on which the evaluation is...

  13. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...; (3) Any relevant data furnished by a governmental agency concerning the person's motor vehicle... administered. (e) The information concerning demonstrated performance skills that the railroad shall retain... the performance skills test(s) that documents the relevant operating facts on which the evaluation is...

  14. 40 CFR 98.287 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... purchases. (2) Annual operating hours. (b) If a CEMS is not used to measure emissions, you must retain records for the information listed in this paragraph (b): (1) Records of all analyses and calculations conducted for reported data listed in § 98.286(b). (2) Records of all petroleum coke purchases. (3)...

  15. 50 CFR Table 11 to Part 679 - BSAI Retainable Percentages

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false BSAI Retainable Percentages 11 Table 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679...

  16. Keeping the Best: A Practical Guide to Retaining Key Employees.

    ERIC Educational Resources Information Center

    Bevan, Stephen; Barber, Linda; Robinson, Dilys

    This book, which is intended to assist human resource professionals and line managers in the United Kingdom, is a practical guide to retaining key employees. Discussed in the introduction are the relationship between downsizing and retention, problems that retention difficulties pose for human resource management, and the effects of retention…

  17. Six Types of Teachers: Recruiting, Retaining and Mentoring the Best

    ERIC Educational Resources Information Center

    Fiore, Douglas J.; Whitaker, Todd

    2004-01-01

    This book helps principals and all others who hire and retain teachers to sharpen their ability to hire better teachers for their schools, improve the ones who are already there, and keep their best and brightest on board. It demonstrates that the quality of the people on staff will ultimately determine the quality of the school and the success of…

  18. 12. View of the swimming pool retaining wall, the steps, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View of the swimming pool retaining wall, the steps, ascending to the rock garden, and the Belvedere (more distant view). The view includes the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and a honey locust (Gleditsia triacanthos). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  19. 13. View of the swimming pool retaining wall, the steps, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View of the swimming pool retaining wall, the steps, ascending to the rock garden, and the Belvedere (less distant view). The view includes the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and a honey locust (Gleditsia triacanthos). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  20. 40 CFR 98.477 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Records that must be retained. 98.477 Section 98.477 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Injection of Carbon Dioxide § 98.477 Records that must...