Science.gov

Sample records for reinforced soil retaining

  1. Analysis of foundations on reinforced soil

    NASA Astrophysics Data System (ADS)

    Brown, B. S.; Poulos, H. G.

    1980-10-01

    A finite element model of reinforced earth is used to investigate the increase in bearing capacity and stiffness of a foundation due to the placement of reinforcement in the soil. The analysis is used to examine the effect of reinforcement on the load settlement behavior of a strip foundation founded on a c-theta soil. It is shown that the improvement in foundation performance depends on both the number of reinforcing layers and on the concentration (surface area per unit width of footing) of the reinforcement. The case of a footing on a reinforced soil mass overlying a cavity or a very soft zone is also analyzed, and the reinforced soil is shown to result in a significant improvement in footing performance.

  2. 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.

  3. 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)

  4. Rehabilitation of maxillary arch with attachment-retained mesh-reinforced single complete denture.

    PubMed

    Vamsi Krishna, C H; Rao, A Kaleshwar; Sekhar, N Chandra; Shastry, Y Mahadev

    2014-02-26

    Fabrication of conventional complete dentures was one of the most commonly advised treatment options to mange edentulous patients since many years. One of the commonly encountered challenging tasks in prosthodontics is a clinical situation in which patients have maxillary completely edentulous arches opposing mandibular natural dentition. This situation can be effectively managed by retaining some of the natural teeth as overdenture abutments. Tooth supported overdenture retained by attachments will improve retention, support and stability, and reduces rate of ridge resorption along with psychological benefits to the patients by providing tactile sensation. The present case report describes management of patients with edentulous maxillary arch opposing natural mandibular dentition-rehabilitated attachment-retained mesh-reinforced overdenture.

  5. 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.

  6. 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. PMID:15206522

  7. Metal-reinforced single implant mandibular overdenture retained by an attachment: a clinical report.

    PubMed

    Grageda, Edgar; Rieck, Bastian

    2014-01-01

    Results of studies have shown that a single implant mandibular overdenture significantly increases the satisfaction and quality of life of patients with edentulism. The single implant-retained overdenture has the additional advantage of being less expensive and invasive than a 2-implant supported overdenture but has a high incidence of fracture of the acrylic resin base at the point of the implant. The treatment, design, and fabrication of a metal-reinforced single-implant mandibular overdenture with the Locator attachment as a retention device is described.

  8. 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.

  9. Analysis of Different Positions of Fiber-Reinforced Composite Retainers versus Multistrand Wire Retainers Using the Finite Element Method

    PubMed Central

    Jahanbin, Arezoo; Abtahi, Mostafa; Heravi, Farzin; Hoseini, Mohsen

    2014-01-01

    Background. The aim of this study was to evaluate root displacement of the lower incisors fixed with FRC in different positions versus FSW retainers using the finite element method. Materials and Methods. 3D finite element models were designed for a mandibular anterior segment: Model 1: flexible spiral wire bonded to the lingual teeth surfaces, Model 2: FRC bonded to the upper third of lingual teeth surfaces, and Model 3: FRC bonded to the middle third. FE analysis was performed for three models and then tooth displacements were evaluated. Results. In contrast to lateral incisors and canines, the FSW retainer caused the central teeth to move more than the teeth bonded with FRC in both loadings. Comparison between Models 2 and 3 (in vertical loading) showed that FRC retainers that bonded at the upper third of lingual teeth surfaces made central and canine teeth move less than FRC retainers bonded at the middle third; however, for lateral teeth it was the opposite. Conclusion. FRC retainers bonded at the upper third of lingual teeth surfaces make central and canine teeth move less than FRC retainers bonded at the middle third in vertical loading; however, for lateral teeth it was the opposite. PMID:25400664

  10. 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

  11. 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.

  12. 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.

  13. [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.

  14. [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. PMID:23715455

  15. 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

  16. 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. PMID:18550353

  17. 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

  18. Fracture strength of direct surface-retained fixed partial dentures: effect of fiber reinforcement versus the use of particulate filler composites only.

    PubMed

    Kumbuloglu, Ovul; Ozcan, Mutlu; User, Atilla

    2008-03-01

    This study compared the fracture strengths and analyzed the failure types of direct, surface-retained, anterior fixed-partial-dentures (FPD), reinforced with four types of fiber-reinforced composites (FRC) versus non-fiber-reinforced FPDs made of three particulate filler composites (PFC). To this end, surface-retained anterior FPDs (N = 70, 10 per group) were prepared and divided into seven experimental groups, where Group 1: FRC1 (everStick) + PFC1 (Clearfil Photo Posterior); Group 2: FRC2 (BR 100) + PFC1; Group 3: FRC3 (Interling) + PFC1; Group 4: FRC4 (Ribbond) + PFC1; Group 5: PFC1 only; Group 6: PFC2 only (Sinfony); and Group 7: PFC3 only (Estenia). Fracture strength test was performed after water storage at 37 degrees C for three days (universal testing machine, 1 mm/min). No significant differences were found among the four FRC types veneered with PFC1 (1490 +/- 548--1951 +/- 335 N) (p < 0.05) (ANOVA, Tukey's test). Among all the experimental groups, PFC1 presented a significantly higher mean value (2061 +/- 270 N) than PFC2 (1340 +/- 395 N) (p < 0.05) and all the other FRC-reinforced groups (p < 0.05). Complete pontic fracture was 100% and 70% for PFC2 and PFC3 respectively. PMID:18540392

  19. 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.

  20. Survival of post-treatment canine-to-canine lingual retainers with fiber-reinforced composite resin: a retrospective study

    PubMed Central

    Farronato, Davide; Briguglio, Roberto; Mangano, Francesco; Azzi, Lorenzo; Grossi, Giovanni Battista; Briguglio, Francesco

    2014-01-01

    Summary The aim of the study is to evaluate the long term results of ribbond retainer after orthodontic treatment. One hundred and thirty patients who were orthodontically treated satisfied the inclusion criteria of having received a semipermanent retention were treated with FRC lingual retainers (Ribbond ®). It was performed a follow up evaluation after 2 years average from the retainer application and any complication or failure was recorded. Data from 119 remaining patients that met the inclusion criteria were analyzed and no instances of loosening were observed. It may be concluded that orthodontic canine-to-canine FRC retainers provide aneffective means of retaining realigned anterior teeth for at least two years. PMID:25506411

  1. 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).

  2. [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.

  3. 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

  4. Biomechanical comparison of implant retained fixed partial dentures with fiber reinforced composite versus conventional metal frameworks: a 3D FEA study.

    PubMed

    Erkmen, Erkan; Meriç, Gökçe; Kurt, Ahmet; Tunç, Yahya; Eser, Atılım

    2011-01-01

    Fiber reinforced composite (FRC) materials have been successfully used in a variety of commercial applications. These materials have also been widely used in dentistry. The use of fiber composite technology in implant prostheses has been previously presented, since they may solve many problems associated with metal alloy frameworks such as corrosion, complexity of fabrication and high cost. The hypothesis of this study was that an FRC framework with lower flexural modulus provides more even stress distribution throughout the implant retained fixed partial dentures (FPDs) than a metal framework does. A 3-dimensional finite element analysis was conducted to evaluate the stress distribution in bone, implant-abutment complex and prosthetic structures. Hence, two distinctly different models of implant retained 3-unit fixed partial dentures, composed of Cr-Co and porcelain (M-FPD model) or FRC and particulate composite (FRC-FPD model) were utilized. In separate load cases, 300 N vertical, 150 N oblique and 60 N horizontal forces were simulated. When the FRC-FPD and M-FPD models were compared, it was found that all investigated stress values in the M-FPD model were higher than the values in the FRC-FPD model except for the stress values in the implant-abutment complex. It can be concluded that the implant supported FRC-FPD could eliminate the excessive stresses in the bone-implant interface and maintain normal physiological loading of the surrounding bone, therefore minimizing the risk of peri-implant bone loss due to stress-shielding. PMID:21094484

  5. [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. PMID:17615891

  6. 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

  7. 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.

  8. Quantifying root-reinforcement of river bank soils by four Australian tree species

    NASA Astrophysics Data System (ADS)

    Docker, B. B.; Hubble, T. C. T.

    2008-08-01

    The increased shear resistance of soil due to root-reinforcement by four common Australian riparian trees, Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata and Acacia floribunda, was determined in-situ with a field shear-box. Root pull-out strengths and root tensile-strengths were also measured and used to evaluate the utility of the root-reinforcement estimation models that assume simultaneous failure of all roots at the shear plane. Field shear-box results indicate that tree roots fail progressively rather than simultaneously. Shear-strengths calculated for root-reinforced soil assuming simultaneous root failure, yielded values between 50% and 215% higher than directly measured shear-strengths. The magnitude of the overestimate varies among species and probably results from differences in both the geometry of the root-system and tensile strengths of the root material. Soil blocks under A. floribunda which presents many, well-spread, highly-branched fine roots with relatively higher tensile strength, conformed most closely with root model estimates; whereas E. amplifolia, which presents a few, large, unbranched vertical roots, concentrated directly beneath the tree stem and of relatively low tensile strength, deviated furthest from model-estimated shear-strengths. These results suggest that considerable caution be exercised when applying estimates of increased shear-strength due to root-reinforcement in riverbank stability modelling. Nevertheless, increased soil shear strength provided by tree roots can be calculated by knowledge of the Root Area Ratio ( RAR) at the shear plane. At equivalent RAR values, A. floribunda demonstrated the greatest earth reinforcement potential of the four species studied.

  9. 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.

  10. [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.

  11. 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

  12. Load-bearing capacity of indirect inlay-retained fixed dental prostheses made of particulate filler composite alone or reinforced with E-glass fibers impregnated with various monomers.

    PubMed

    Özcan, Mutlu; Koekoek, Winand; Pekkan, Gurel

    2012-08-01

    The load-bearing capacity and failure types of indirect inlay-retained fixed dental prostheses (FDP), made of particulate filler composite (PFC) (Estenia) alone or reinforced with E-glass fibers impregnated with various monomers were evaluated. Indirect inlay-retained FDPs were made between first premolars and first molars (N=30, 10/per group). The inlay parts of the specimens were silica coated and silanized and the specimens were cemented with dual-polymerized resin cement under ultrasonic vibrations. The experimental groups were as follows: Group 1: FRC1 (BR-100, UTMA) + PFC; Group 2: FRC2 (everStick C&B, Bis-GMA/PMMA) + PFC; Group 3: PFC only. The specimens were kept in distilled water at 37 °C for one month and then subjected to fracture strength test. No significant difference was found between the Group 1 and Group 2 FDPs (1357±301 N and 1213±316 N, respectively) (p>0.05) (ANOVA). Group 3 (856±299 N) showed significantly lower results than those of FRC reinforced groups (p<0.05). Failure analyses revealed no debonding of any of the FDPs from the inlay cavities. FDPs made of PFC only showed mainly catastrophic fracture of the pontic. In the FRC reinforced groups, predominantly delamination of the veneering was observed. The use of silica coating and silanization in combination with the dual-polymerized resin cement used; under ultrasonic cementation procedure provided sufficient adhesion to withstand static loading forces at the cementation interface, since the failures were predominantly delamination of the veneering in the FRC reinforced groups.

  13. Bicruciate retaining

    PubMed Central

    2016-01-01

    Total knee replacement (TKR) is a procedure used to treat knee arthropathy. Patients’ dissatisfaction is still relevant (literature reports dissatisfaction rates as high as 40%). The anterior cruciate ligament is usually removed while performing a total knee arthroplasty, thus changing knee biomechanics. As patients’ mean age to surgery is decreasing, bicruciate retaining models, which preserve normal biomechanics, may be useful in increasing patients’ outcomes. Limited data concerning bicruciate retaining arthroplasty is available; although clinical results are encouraging, there are concerns regarding surgical exposure, anterior cruciate integrity evaluation, and implant fixation. PMID:27162778

  14. Three-dimensional analysis of the seismic behaviour of micropiles used in the reinforcement of saturated soil

    NASA Astrophysics Data System (ADS)

    Ousta, R.; Shahrour, I.

    2001-02-01

    This paper includes a numerical study of the behaviour of micropiles used for the reinforcement of saturated soil. Analysis is carried out using the (u-p) formulation (displacement for the solid phase and pore-pressure for the fluid phase) implemented in a three-dimensional finite element program. The soil behaviour is described by means of a cyclic elastoplastic constitutive relation which was developed within the framework of the bounding surface concept. The paper is composed of three parts. The first one is concerned with a presentation of the numerical model; the second includes analysis of the seismic behaviour of a single micropile; the last part deals with the group effect under seismic loading.

  15. 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.

  16. 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

  17. In vivo orthodontic retainer survival - a review

    PubMed Central

    LABUNET, ANCA VICTORIA; BADEA, MÎNDRA

    2015-01-01

    Background Relapse following orthodontic treatment is a constant concern of orthodontists. Fixed retention is preferred especially for the lower arch by most orthodontists. Objectives This review focuses on in vivo studies. The main objective is to determine the survival rates of different types of retainer: glass-fiber reinforced composite resin, polyethylene or multistrand stainless steel wire bonded to each tooth from canine to canine in the mandibular arch. A second objective is to assess which of these types is less likely to cause additional problems and the third objective is to evaluate the factors that may influence retainer survival. Results and conclusions There were 8 studies identified that matched the objectives stated. Current in vivo studies on survival rate take little notice of the role of the material used for bonding of the fixed retainer. It is not possible to draw a conclusion on reliability of new types of retainers glass fiber reinforced composite resin or polyethylene compared to multistrand stainless steel wire. The multistrand wire remains the gold standard for fixed retention. Although it is a logical outcome that retainer survival is dependent on the application technique, there seems to be no research outcome proving that operator experience, moisture control are essential, nor does patient age or sex have statistically proven effects on survival rates. Adequate studies that involve such aspects should be performed. PMID:26609260

  18. Reliability-based design optimization of reinforced concrete structures including soil-structure interaction using a discrete gravitational search algorithm and a proposed metamodel

    NASA Astrophysics Data System (ADS)

    Khatibinia, M.; Salajegheh, E.; Salajegheh, J.; Fadaee, M. J.

    2013-10-01

    A new discrete gravitational search algorithm (DGSA) and a metamodelling framework are introduced for reliability-based design optimization (RBDO) of reinforced concrete structures. The RBDO of structures with soil-structure interaction (SSI) effects is investigated in accordance with performance-based design. The proposed DGSA is based on the standard gravitational search algorithm (GSA) to optimize the structural cost under deterministic and probabilistic constraints. The Monte-Carlo simulation (MCS) method is considered as the most reliable method for estimating the probabilities of reliability. In order to reduce the computational time of MCS, the proposed metamodelling framework is employed to predict the responses of the SSI system in the RBDO procedure. The metamodel consists of a weighted least squares support vector machine (WLS-SVM) and a wavelet kernel function, which is called WWLS-SVM. Numerical results demonstrate the efficiency and computational advantages of DGSA and the proposed metamodel for RBDO of reinforced concrete structures.

  19. 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

  20. Detail view of reinforced concrete of Bonita Ridge Access Road ...

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

    Detail view of reinforced concrete of Bonita Ridge Access Road Retaining Wall, camera facing northwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  1. The retained placenta.

    PubMed

    Weeks, Andrew D

    2008-12-01

    The incidence and importance of retained placenta (RP) varies greatly around the world. In less developed countries, it affects about 0.1% of deliveries but has up to 10% case fatality rate. In more developed countries, it is more common (about 3% of vaginal deliveries) but very rarely associated with mortality. There are three main types of retained placenta following the vagina delivery: placenta adherens (when there is failed contraction of the myometrium behind the placenta), trapped placenta (a detached placenta trapped behind a closed cervix) and partial accreta (when there is a small area of accreta preventing detachment). All can be treated by manual removal of placenta, which should be carried out at 30-60 minutes postpartum. Medical management is also an option for placenta adherens and trapped placenta. The need for manual removal can be reduced by 20% by the use of intraumbilical oxytocin (30 i.u. in 30 mL saline). A trapped placenta may respond to glyceryl trinitrate (500 mcg sublingually) or gentle, persistent, controlled cord traction.

  2. 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.

  3. 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.

  4. Retained Placenta Accreta Mimicking Choriocarcinoma

    PubMed Central

    Kohi, Maureen P.; Rizzuto, Gabrielle A.; Fidelman, Nicholas; Lucero, Jennifer; Thiet, Mari-Paule

    2015-01-01

    This case demonstrates a rare event of retained invasive placenta masquerading as choriocarcinoma. The patient presented with heavy vaginal bleeding following vaginal delivery complicated by retained products of conception. Ultrasound and computed tomography demonstrated a vascular endometrial mass, invading the uterine wall and raising suspicion for choriocarcinoma. Hysterectomy revealed retained invasive placenta. PMID:26495146

  5. Quick locking/unlocking retainer

    NASA Technical Reports Server (NTRS)

    Okamoto, G.; Williams, B. B.

    1979-01-01

    Spring clip retainer may prove more convenient than clamps or wingnut and stud combination when holding two small parts together in test fixtures and other applications where parts must be frequently moved or changed.

  6. 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

  7. 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.

  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. 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)

  10. Retaining-Ring Installation Tool

    NASA Technical Reports Server (NTRS)

    Christian, S.

    1983-01-01

    New tool eliminates damage to ring through improper tool use. Tool installs spiral-wound retaining rings quickly, reliably, and safely. Tool inserts rings in splined or irregularly shaped bores, bores at bottom of deep ring and slides it along bore until it nests in groove. Pistons are moved by variety of linkages.

  11. 47 CFR 32.4550 - Retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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...

  12. 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.

  13. 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

  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. 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...

  16. 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...

  17. 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...

  18. 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...

  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. Reinforced Carbon Nanotubes.

    SciTech Connect

    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.

  2. 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.

  3. The Non-finished, Non-well Compacted Soil of the Crest of Zayzoun Dam, the Technical and Administrative Errors, and the Correct Ways of its Reinforcement and Renovation

    NASA Astrophysics Data System (ADS)

    Hamze, Youssef; Stanivska, Anna

    Zayzoun dam is one of the irrigation elements of the valley of (Alkhab) in northern Syria; its exploitation started in 1996 and breached on June 4th, 2002. There were many experts searching for the causes of its failure and the correct ways of its renovation. There were many reports written about the failure with different opinions, and we have been one of these experts with an objective opinion. The principal aim was to study all the technical and administrative components of the dam, and to analyze the existing and the new laboratory testing. The soil of the unfinished summit of the dam, in the end, was found to be the real cause that led to its failure. These causes will be analyzed in order to avoid them in the future and to find the suitable ways of its renovation and reinforcement.

  4. 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

  5. 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…

  6. 12 CFR 1805.504 - Retained earnings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Retained earnings accumulated after the end of the Applicant's most recent fiscal year ending prior to the... over the Applicant's most recent fiscal year (e.g., retained earnings at the end of fiscal year 2003... that has occurred over the Applicant's three most recent fiscal years. (c)(1) In the case of...

  7. 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

  8. 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. PMID:23499392

  9. 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

  10. 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

  11. 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.

  12. Reinforcement, Expectancy, and Learning

    ERIC Educational Resources Information Center

    Bolles, Robert

    1972-01-01

    Surveys some of the difficulties currently confronting the reinforcement concept and cosiders some alternatives to reinforcement as the fundamental basis of learning. Two specific alternatives considered are: an incentive motivation approach and a cognitive approach. (Author)

  13. 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

  14. 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)

  15. [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.

  16. General level of reinforcement.

    PubMed

    Cautela, J R

    1984-06-01

    A concept of General Level of Reinforcement (GLR) is introduced. This concept is defined as the number, quality and duration of reinforcements per unit time. The assumptions of this theory are discussed. A crucial assumption is that the theory is related to psychological and physiological well-being. Ways to measure general level of reinforcement are described, and clinical implications presented. Methods to increase the level of reinforcement, such as covert reinforcement and the Self-Control Triad, are specified. Finally, suggestions for research are provided.

  17. 15 CFR 762.2 - Records to be retained.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Records to be retained. 762.2 Section... § 762.2 Records to be retained. (a) Records required to be retained. The records required to be retained... section describes records that are required to be retained. Other parts, sections, or supplements of...

  18. 15 CFR 762.2 - Records to be retained.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Records to be retained. 762.2 Section... § 762.2 Records to be retained. (a) Records required to be retained. The records required to be retained... section describes records that are required to be retained. Other parts, sections, or supplements of...

  19. 15 CFR 762.2 - Records to be retained.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false Records to be retained. 762.2 Section... § 762.2 Records to be retained. (a) Records required to be retained. The records required to be retained... section describes records that are required to be retained. Other parts, sections, or supplements of...

  20. 15 CFR 762.2 - Records to be retained.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Records to be retained. 762.2 Section... § 762.2 Records to be retained. (a) Records required to be retained. The records required to be retained.... Paragraph (a) of this section describes records that are required to be retained. Other parts, sections,...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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…

  7. 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.

  8. 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. PMID:24982951

  9. 45 CFR 1611.9 - Retainer agreements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to the client or for legal services provided to the client by a private attorney pursuant to 45 CFR... 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,...

  10. Retaining Principals. ERIC Digest Number 147.

    ERIC Educational Resources Information Center

    Hertling, Elizabeth

    This Digest examines the reasons why--outside of retirement--school principals leave their jobs. It also lists strategies districts can employ to retain principals. Many principals exit their profession because of the long hours, the workload and complexity of the job, the unending supervision of evening activities, the minimal pay difference…

  11. Reteniendo los directores (Retaining Principals). ERIC Digest.

    ERIC Educational Resources Information Center

    Hertling, Elizabeth

    This digest in Spanish examines the reasons why--outside of retirement--school principals leave their jobs. It also lists strategies districts can employ to retain principals. Many principals exit their profession because of the long hours, the workload and complexity of the job, the unending supervision of evening activities, the minimal pay…

  12. Recruiting, Retaining, and Fairly Compensating Our Teachers

    ERIC Educational Resources Information Center

    Lynch, Matthew

    2012-01-01

    This article examines three interlinked problems facing public schools today: how to recruit, retain, and pay our teachers. The article begins with an overview of the current situation in the United States, paying particular attention to schools in areas where minorities are the majority. It goes on to examine some of the causes of teacher…

  13. Stopping the Leak: Retaining Beginning Teachers

    ERIC Educational Resources Information Center

    Richardson, Rita C.; Glessner, Linda L.; Tolson, Homer

    2007-01-01

    The need for teacher retention has prompted numerous American states to provide programs for training mentors. The goal of mentor training is to offer a support mechanism that will retain novice teachers and assist them in developing their teaching skills. Such a program is the Texas Beginning Educator Support System (TxBESS) which has supported…

  14. 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…

  15. 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.

  16. 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.

  17. 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…

  18. 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.

  19. 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

  20. 23-gauge vitrectomy for retained lens material.

    PubMed

    Bhandari, Ramanath; Ernst, Benjamin J; Stafeeva, Ksenia; Mandava, Naresh; Quiroz-Mercado, Hugo

    2012-07-01

    A technique for removal of retained lens material is described with a three-port 23-gauge vitrectomy system. Removal of the core vitreous is first performed, followed by removal of the cortical vitreous. All vitreous adhesions to the lens are cleared. The cut rate is then decreased to 1,500 cuts per minute, and vacuum increased to 600 mm Hg. The cortical lens material is cleared first, and then the nuclear material is taken with the same vitrectomy probe using the light pipe to assist in crushing the nuclear fragments. With this technique, even large dense nuclear and cortical retained lens material can be removed from the vitreous chamber without the need for a fragmatome. PMID:22692723

  1. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time/temperature requirements set forth in 9 CFR 381.66. Additional purposes that could be included are determining... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Retained water. 441.10 Section...

  2. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time/temperature requirements set forth in 9 CFR 381.66. Additional purposes that could be included are determining... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Retained water. 441.10 Section...

  3. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time/temperature requirements set forth in 9 CFR 381.66. Additional purposes that could be included are determining... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Retained water. 441.10 Section...

  4. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time/temperature requirements set forth in 9 CFR 381.66. Additional purposes that could be included are determining... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Retained water. 441.10 Section...

  5. 9 CFR 441.10 - Retained water.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time/temperature requirements set forth in 9 CFR 381.66. Additional purposes that could be included are determining... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Retained water. 441.10 Section...

  6. 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.

  7. 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

  8. Retaining latch for a water pit gate

    DOEpatents

    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.

  9. Dynamic response of cantilever retaining walls

    SciTech Connect

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

    1996-10-01

    A critical evaluation is made of the response to horizontal ground shaking of flexible cantilever retaining walls that are elastically constrained against rotation at their base. The retained medium is idealized as a uniform, linear, viscoelastic stratum of constant thickness and semi-infinite extent in the horizontal direction. The parameters varied include the flexibilities of the wall and its base, the properties of the retained medium, and the characteristics of the ground motion. In addition to long-period, effectively static excitations, both harmonic base motions and an actual earthquake record are considered. The response quantities examined include the displacements of the wall relative to the moving base, the wall pressures, and the associated shears and bending moments. The method of analysis employed is described only briefly, emphasis being placed on the presentation and interpretation of the comprehensive numerical solutions. It is shown that, for realistic wall flexibilities, the maximum wall forces are significantly lower than those obtained for fixed-based rigid walls and potentially of the same order of magnitude as those computed by the Mononobe-Okabe method.

  10. 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.

  11. Reinforced plastics durability

    SciTech Connect

    Pritchard, G.

    1999-01-01

    Written especially for first-time users of reinforced plastics. The book offers substantial introductory information with key concepts. Chapters examine the long-term threats to the integrity of reinforced plastics: outdoor weathering, solvent/water attack, high temperatures, and repetitive stress.

  12. "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.

  13. "Reinforcement" in behavior theory.

    PubMed

    Schoenfeld, W N

    1995-01-01

    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 stand-point of reflex behavior theory.

  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)

    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.

  15. 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.

  16. 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.

  17. Endoscopic removal of retained T- tube fragment.

    PubMed

    Chandrasekar, Thoguluva Seshadri; Murugesh, Mallaiyappan; Radhakrishnan, Subbaiah; Sadagopan, Thiruvengadam; Hussain, Abdul Cadar Mohammed Hameed

    2009-01-01

    T-tube usage is common following common bile duct exploration for calculi and other complex biliary surgeries to ensure proper biliary diversion and healing. A 25-year-old woman was referred from a surgical unit with a history of open cholecystectomy and common bile duct exploration for cholelithiasis and choledocholithiasis with T-tube placement in the common bile duct for postoperative biliary diversion. While retrieving the T-tube, it got fractured and the fragment remained in the bile duct. We report a rare case of retained T-tube fragment after T-tube removal that was retrieved endoscopically.

  18. Endoscopic removal of retained T- tube fragment

    PubMed Central

    Chandrasekar, Thoguluva Seshadri; Murugesh, Mallaiyappan; Radhakrishnan, Subbaiah; Sadagopan, Thiruvengadam; Hussain, Abdul cadar Mohammed Hameed

    2009-01-01

    T-tube usage is common following common bile duct exploration for calculi and other complex biliary surgeries to ensure proper biliary diversion and healing. A 25-year-old woman was referred from a surgical unit with a history of open cholecystectomy and common bile duct exploration for cholelithiasis and choledocholithiasis with T-tube placement in the common bile duct for postoperative biliary diversion. While retrieving the T-tube, it got fractured and the fragment remained in the bile duct. We report a rare case of retained T-tube fragment after T-tube removal that was retrieved endoscopically. PMID:21686845

  19. 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.

  20. Endoscopic removal of retained T- tube fragment.

    PubMed

    Chandrasekar, Thoguluva Seshadri; Murugesh, Mallaiyappan; Radhakrishnan, Subbaiah; Sadagopan, Thiruvengadam; Hussain, Abdul Cadar Mohammed Hameed

    2009-01-01

    T-tube usage is common following common bile duct exploration for calculi and other complex biliary surgeries to ensure proper biliary diversion and healing. A 25-year-old woman was referred from a surgical unit with a history of open cholecystectomy and common bile duct exploration for cholelithiasis and choledocholithiasis with T-tube placement in the common bile duct for postoperative biliary diversion. While retrieving the T-tube, it got fractured and the fragment remained in the bile duct. We report a rare case of retained T-tube fragment after T-tube removal that was retrieved endoscopically. PMID:21686845

  1. Reinforcement of Tree Root and Non-frame Method in Slope Stabilization

    NASA Astrophysics Data System (ADS)

    Naoto, I.; Quang, N. Minh

    2009-04-01

    A root fiber can nail a slipping soil mass into the bedrock and thus can increase slope stability. The reinforcement of root fibers is considered as the resultant of tension and shear reinforces occurred in the cross section of root at slip surface. The shear force and bending moment of a deformed root directly prevent against the displacement of unstable soil mass while the tension force increase the friction force between unstable soil and bed rock. Longer displacement of slope causes larger deformation and thus causes larger reinforcement of tree root. In other side, larger root reinforcement results in more slope stability. The reinforcement of tree root and displacement of slipping soil mass depending on each other is the reinforcement mechanism of tree root in a landslide. The mechanism of tree root reinforcement is considered in developing a new soil nail method named Non-frame. By conducting a number of experiments of soil nail stabilizing slope, the alteration process of root reinforcement was performed in various conditions of rainfall and earthquake.

  2. Choice and conditioned reinforcement.

    PubMed

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

    1991-03-01

    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.

  3. Fire test method for graphite fiber reinforced plastics

    NASA Technical Reports Server (NTRS)

    Bowles, K. J.

    1980-01-01

    A potential problem in the use of graphite fiber reinforced resin matrix composites is the dispersal of graphite fibers during accidental fires. Airborne, electrically conductive fibers originating from the burning composites could enter and cause shorting in electrical equipment located in surrounding areas. A test method for assessing the burning characteristics of graphite fiber reinforced composites and the effectiveness of the composites in retaining the graphite fibers has been developed. The method utilizes a modified Ohio State University Rate of Heat Release apparatus. The equipment and the testing procedure are described. The application of the test method to the assessment of composite materials is illustrated for two resin matrix/graphite composite systems.

  4. Fire test method for graphite fiber reinforced plastics

    NASA Technical Reports Server (NTRS)

    Bowles, K. J.

    1980-01-01

    A potential problem in the use of graphite fiber reinforced resin matrix composites is the dispersal of graphite fibers during accidential fires. Airborne, electrically conductive fibers originating from the burning composites could enter and cause shorting in electrical equipment located in surrounding areas. A test method for assessing the burning characteristics of graphite fiber reinforced composites and the effectiveness of the composites in retaining the graphite fibers has been developed. The method utilizes a modified rate of heat release apparatus. The equipment and the testing procedure are described. The application of the test method to the assessment of composite materials is illustrated for two resin matrix/graphite composite systems.

  5. Full-arch metal-resin cement- and screw-retained provisional restoration for immediately loaded implants.

    PubMed

    Baig, Mirza Rustum; Rajan, Gunaseelan

    2010-01-01

    Abstract This article describes the clinical and laboratory procedures involved in the fabrication of laboratory-processed, provisional, screw-retained, implant-supported maxillary and mandibular fixed complete dentures incorporating a cast metal reinforcement for immediate loading of implants. Precise fit is achieved by intraoral luting of the cast frame to milled abutments. Effective splinting of all implants is attained by the metal substructure and retrievability is provided by the screw-retention of the prosthesis. PMID:20553176

  6. Seismic displacement of geosynthetic-reinforced slopes subject to cracks

    NASA Astrophysics Data System (ADS)

    Abd, Akram H.

    2015-09-01

    The kinematical approach of limit analysis associated with pseudo static assumption is employed to evaluate the displacement of geosynthetically reinforced soil slopes subject to cracks. According to existing literature, the seismic displacements for soil slopes have been calculated with the effect of possible cracking being neglected, such cracking is likely to emerge due to an earthquake with even moderately large motion. In this paper, a new technique is proposed to estimate the horizontal displacement of the slope toe for geosynthetically reinforced slopes resulting from a given earthquake postulating a rough estimation of real time crack propagation. The effect of crack formation as part of the failure process during the earthquake on the horizontal displacement of the slope toe is specifically tackled. The seismic displacement is estimated by incorporating a stepwise yield acceleration corresponding to postulated crack propagation. Rotational failure mechanisms accounting for either intact reinforced slopes that can show cracks or reinforced slopes with pre-existing cracks are considered. Two types of reinforcement layouts are employed here; uniformly distributed reinforcement along the slope height and linearly increasing distribution (i.e. the spacing between layers decreases linearly with depth). An example illustrating the procedure for a given earthquake is presented. Results show that the horizontal displacement of the slope toe calculated using the stepwise yield acceleration for both uniform distribution of reinforcement and for linearly increasing distribution can provide a reasonable estimation of the slope displacement. Furthermore, in terms of the slope displacement, linearly increasing distribution yields better results than the uniform layout.

  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. 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

  10. Should PTSD Criterion A be retained?

    PubMed

    Kilpatrick, Dean G; Resnick, Heidi S; Acierno, Ron

    2009-10-01

    Criterion A has been controversial since its inception, partially because it performs a key gate keeping function. Major criticisms of Criterion A of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; American Psychiatric Association, 1994) include that it has resulted in "criterion creep." The authors tested the hypothesis that a nonrestrictive definition would substantially increase posttraumatic stress disorder (PTSD) prevalence by determining PTSD based on Criteria B, C, D, E, and F, without restricting Criterion A in large probability samples of U.S. adolescents and Florida adults. Few PTSD cases occurred in the absence of Criterion A1 events, providing little support for the criterion creep hypothesis. Specific recommendations are to retain Criterion A; permit additional events; consider expanding Criterion A2; consider that either Criterion A1 or A2 be met; and place greater emphasis on Criterion F.

  11. 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).

  12. The substitutability of reinforcers.

    PubMed

    Green, Leonard; Freed, Debra E

    1993-07-01

    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

  13. Preference pulses without reinforcers.

    PubMed

    McLean, Anthony P; Grace, Randolph C; Pitts, Raymond C; Hughes, Christine E

    2014-05-01

    Preference pulses are thought to represent strong, short-term effects of reinforcers on preference in concurrent schedules. However, the general shape of preference pulses is substantially determined by the distributions of responses-per-visit (visit lengths) for the two choice alternatives. In several series of simulations, we varied the means and standard deviations of distributions describing visits to two concurrently available response alternatives, arranged "reinforcers" according to concurrent variable-interval schedules, and found a range of different preference pulses. Because characteristics of these distributions describe global aspects of behavior, and the simulations assumed no local effects of reinforcement, these preference pulses derive from the visit structure alone. This strongly questions whether preference pulses should continue to be interpreted as representing local effects of reinforcement. We suggest an alternative approach whereby local effects are assessed by subtracting the artifactual part, which derives from visit structure, from the observed preference pulses. This yields "residual" preference pulses. We illustrate this method in application to published data from mixed dependent concurrent schedules, revealing evidence that the delivery of reinforcers had modest lengthening effects on the duration of the current visit, a conclusion that is quantitatively consistent with early research on short-term effects of reinforcement.

  14. 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

  15. 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. PMID:12555908

  16. 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.

  17. Detail view of Bonita Ridge Access Road Retaining Wall showing ...

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

    Detail view of Bonita Ridge Access Road Retaining Wall showing drainpipes, camera facing northwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  18. View of northern end of Bonita Ridge Access Road Retaining ...

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

    View of northern end of Bonita Ridge Access Road Retaining Wall, camera facing northwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  19. 40 CFR 98.277 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reference, see § 98.7) or an online measurement system). If an online measurement system is used, you must... retained. In addition to the information required by § 98.3(g), you must retain the records in...

  20. 40 CFR 98.277 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reference, see § 98.7) or an online measurement system). If an online measurement system is used, you must... retained. In addition to the information required by § 98.3(g), you must retain the records in...

  1. 40 CFR 98.277 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reference, see § 98.7) or an online measurement system). If an online measurement system is used, you must... retained. In addition to the information required by § 98.3(g), you must retain the records in...

  2. 40 CFR 98.277 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reference, see § 98.7) or an online measurement system). If an online measurement system is used, you must... retained. In addition to the information required by § 98.3(g), you must retain the records in...

  3. 40 CFR 98.467 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for...

  4. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for...

  5. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for calibration....

  6. 40 CFR 98.467 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for...

  7. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for...

  8. 40 CFR 98.347 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... retained. In addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for...

  9. 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... COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must— (a) Retain its MSDS for as long as the hazardous chemical is known to be at the mine, and (b) Notify...

  10. 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... COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must— (a) Retain its MSDS for as long as the hazardous chemical is known to be at the mine, and (b) Notify...

  11. 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... COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must— (a) Retain its MSDS for as long as the hazardous chemical is known to be at the mine, and (b) Notify...

  12. 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... COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must— (a) Retain its MSDS for as long as the hazardous chemical is known to be at the mine, and (b) Notify...

  13. 30 CFR 47.55 - Retaining an MSDS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Retaining an MSDS. 47.55 Section 47.55 Mineral... COMMUNICATION (HazCom) Material Safety Data Sheets (MSDS) § 47.55 Retaining an MSDS. The operator must— (a) Retain its MSDS for as long as the hazardous chemical is known to be at the mine, and (b) Notify...

  14. Every reinforcer counts: reinforcer magnitude and local preference.

    PubMed Central

    Davison, Michael; Baum, William M

    2003-01-01

    Six pigeons were trained on concurrent variable-interval schedules. Sessions consisted of seven components, each lasting 10 reinforcers, with the conditions of reinforcement differing between components. The component sequence was randomly selected without replacement. In Experiment 1, the concurrent-schedule reinforcer ratios in components were all equal to 1.0, but across components reinforcer-magnitude ratios varied from 1:7 through 7:1. Three different overall reinforcer rates were arranged across conditions. In Experiment 2, the reinforcer-rate ratios varied across components from 27:1 to 1:27, and the reinforcer-magnitude ratios for each alternative were changed across conditions from 1:7 to 7:1. The results of Experiment 1 replicated the results for changing reinforcer-rate ratios across components reported by Davison and Baum (2000, 2002): Sensitivity to reinforcer-magnitude ratios increased with increasing numbers of reinforcers in components. Sensitivity to magnitude ratio, however, fell short of sensitivity to reinforcer-rate ratio. The degree of carryover from component to component depended on the reinforcer rate. Larger reinforcers produced larger and longer postreinforcer preference pulses than did smaller reinforcers. Similar results were found in Experiment 2, except that sensitivity to reinforcer magnitude was considerably higher and was greater for magnitudes that differed more from one another. Visit durations following reinforcers measured either as number of responses emitted or time spent responding before a changeover were longer following larger than following smaller reinforcers, and were longer following sequences of same reinforcers than following other sequences. The results add to the growing body of research that informs model building at local levels. PMID:13677611

  15. 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

  16. 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

  17. 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.

  18. Retaining volunteers in volunteer computing projects.

    PubMed

    Darch, Peter; Carusi, Annamaria

    2010-09-13

    Volunteer computing projects (VCPs) have been set up by groups of scientists to recruit members of the public who are asked to donate spare capacity on their personal computers to the processing of scientific data or computationally intensive models. VCPs serve two purposes: to acquire significant computing capacity and to educate the public about science. A particular challenge for these scientists is the retention of volunteers as there is a very high drop-out rate. This paper develops recommendations for scientists and software engineers setting up or running VCPs regarding which strategies to pursue in order to improve volunteer retention rates. These recommendations are based on a qualitative study of volunteers in a VCP (climateprediction.net). A typology of volunteers has been developed, and three particularly important classes of volunteers are presented in this paper: for each type of volunteer, the particular benefits they offer to a project are described, and their motivations for continued participation in a VCP are identified and linked to particular strategies. In this way, those setting up a VCP can identify which types of volunteers they should be particularly keen to retain, and can then find recommendations to increase the retention rates of their target volunteers.

  19. Reinforcement of hydrogels using three-dimensionally printed microfibres.

    PubMed

    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

    2015-01-01

    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. PMID:25917746

  20. 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.

  1. 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. PMID:21999693

  2. History of reinforced plastics

    SciTech Connect

    Milewski, J.V.; Rosato, D.V.

    1981-01-01

    This history of reinforced plastics is told by combining the individual histories of each reinforcement and the way in which they added to and changed the direction and rate of growth of the industry. The early history is based on all resins, fillers, and fibers found in nature. Then came the Baekeland revolution with the first synthetic resin which lasted about 25 years, at which time synthetic fiber glass and polyester resin dramatically changed the industry. Now, for the 1980s, the high modulus fibers developed 10 to 20 years ago are reshaping the industry. 32 figures.

  3. 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.

  4. 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. PMID:17970264

  5. Evaluating The Influence of Postsession Reinforcement on Choice of Reinforcers

    PubMed Central

    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. PMID:17970264

  6. 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.

  7. 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…

  8. 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…

  9. A three dimensional embedded beam element for reinforced geomaterials

    NASA Astrophysics Data System (ADS)

    Sadek, Machhour; Shahrour, Isam

    2004-08-01

    This paper presents the formulation and verification of a 3D embedded beam element, which is intended for numerical modelling of three dimensional problems concerned by reinforced geomaterials. This element permits analysis of reinforced geomaterial structures with simplified meshes, that do not need to account for reinforcement orientation. The paper is composed of four sections. Section 1 discusses the need for the development of a particular beam element for soil reinforcement, which can be easily used in practical applications. Section 2 describes the mathematical formulation of this element, while Section 3 deals with its verification on various examples. Section 4 illustrates an application of this element by analysing the behaviour of a group of micropiles containing inclined elements and subjected to lateral loading. Copyright

  10. Turbomachine blade reinforcement

    DOEpatents

    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.

  11. 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…

  12. Al-based metal matrix composites reinforced with nanocrystalline Al-Ti-Ni particles

    NASA Astrophysics Data System (ADS)

    Scudino, S.; Ali, F.; Surreddi, K. B.; Prashanth, K. G.; Sakaliyska, M.; Eckert, J.

    2010-07-01

    Al-based metal matrix composites containing different volume fractions of nanocrystalline Al70Ti20Ni10 reinforcing particles have been produced by powder metallurgy and the effect of the volume fraction of reinforcement on the mechanical properties of the composites has been studied. Room temperature compression tests reveal a considerable improvement of the mechanical properties as compared to pure Aluminum. The compressive strength increases from 155 MPa for pure Al to about 200 and 240 MPa for the samples with 20 and 40 vol.% of reinforcement, respectively, while retaining appreciable plastic deformation with a fracture strain ranging between 43 and 28 %.

  13. Retaining clinician-scientists: nature versus nurture.

    PubMed

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

    2014-05-01

    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. PMID:24867910

  14. 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.

  15. Quasicrystalline particulate reinforced aluminum composite

    SciTech Connect

    Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

    1997-07-01

    Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

  16. 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.

  17. 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…

  18. Developmental Reinforcement and Special Education.

    ERIC Educational Resources Information Center

    Garris, Raymond P.

    The author uses a developmental model (1) to describe the developmental reinforcement process as it occurs in a child's life, using a hierarchical concept, and (2) to discuss some educational consequences of a reinforcement deficit. The developmental reinforcement process is composed of a hierarchy of four levels. Development takes place in…

  19. 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…

  20. 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. PMID:25693154

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

    PubMed Central

    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. PMID:18595284

  2. 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

  3. Hydraulic Properties of Unsaturated Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 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

  5. 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.

  6. 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. PMID:20885815

  7. Nanostructured composite reinforced material

    DOEpatents

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    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.

  8. 40 CFR 98.367 - 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. 98.367 Section 98.367 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Manure Management § 98.367 Records that must be retained....

  9. 40 CFR 98.367 - 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. 98.367 Section 98.367 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Manure Management § 98.367 Records that must be retained....

  10. 40 CFR 98.367 - 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. 98.367 Section 98.367 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Manure Management § 98.367 Records that must be retained....

  11. 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…

  12. 40 CFR 98.437 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.437 Records that must be retained. (a) In... closed-cell foams must retain the following records substantiating each of the imports that they report... entry form. (4) Ports of entry through which the pre-charged equipment or closed-cell foams passed....

  13. 40 CFR 98.437 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.437 Records that must be retained. (a) In... closed-cell foams must retain the following records substantiating each of the imports that they report... entry form. (4) Ports of entry through which the pre-charged equipment or closed-cell foams passed....

  14. 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

  15. Retrieval of a defective cement-retained implant prosthesis.

    PubMed

    Schoenbaum, Todd R; McLaren, Edward A

    2013-10-01

    As the popularity of cement-retained implant prosthetics grows, so, too, does the need for retreatment. The predictable removal of cement-retained implant crowns has often proven difficult due to a multitude of variables, including locating the access and stripped screws. The techniques discussed in this article address these issues, thus simplifying the retreatment process.

  16. View of middle portion of Bonita Ridge Access Road Retaining ...

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

    View of middle portion of Bonita Ridge Access Road Retaining Wall, showing Signal Corps Radar 296 Station 5 Tower concrete pier (top center), camera facing northwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  17. Oblique view of Bonita Ridge Access Road Retaining Wall, showing ...

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

    Oblique view of Bonita Ridge Access Road Retaining Wall, showing southernmost portion of intact wall and portion of concrete drainage ditch from Signal Corps Radar 296 Station 5 Transmitter Building foundation above, camera facing west-north - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  18. Contextual view of Bonita Ridge Access Road Retaining Wall, showing ...

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

    Contextual view of Bonita Ridge Access Road Retaining Wall, showing concrete stairway and ramp with Army Fire Control Station (Buildings 621 and 622) at far left, camera facing southwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  19. 49 CFR 379.3 - Records required to be retained.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PRESERVATION OF RECORDS § 379.3 Records required to be retained. Companies subject to this part shall retain... the obligation of the subject company to maintain records that adequately support financial...

  20. 5 CFR 536.306 - Limitation on retained rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... other law or regulation to the rate of basic pay the employee would have received but for this... AND PAY RETENTION Pay Retention § 536.306 Limitation on retained rates. (a) A retained rate may not at any time exceed the rate payable for level IV of the Executive Schedule. (b) When an...

  1. Robust reinforcement learning.

    PubMed

    Morimoto, Jun; Doya, Kenji

    2005-02-01

    This letter proposes a new reinforcement learning (RL) paradigm that explicitly takes into account input disturbance as well as modeling errors. The use of environmental models in RL is quite popular for both offline learning using simulations and for online action planning. However, the difference between the model and the real environment can lead to unpredictable, and often unwanted, results. Based on the theory of H(infinity) control, we consider a differential game in which a "disturbing" agent tries to make the worst possible disturbance while a "control" agent tries to make the best control input. The problem is formulated as finding a min-max solution of a value function that takes into account the amount of the reward and the norm of the disturbance. We derive online learning algorithms for estimating the value function and for calculating the worst disturbance and the best control in reference to the value function. We tested the paradigm, which we call robust reinforcement learning (RRL), on the control task of an inverted pendulum. In the linear domain, the policy and the value function learned by online algorithms coincided with those derived analytically by the linear H(infinity) control theory. For a fully nonlinear swing-up task, RRL achieved robust performance with changes in the pendulum weight and friction, while a standard reinforcement learning algorithm could not deal with these changes. We also applied RRL to the cart-pole swing-up task, and a robust swing-up policy was acquired.

  2. 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.

  3. Retained and recurrent bile duct stones. Surgical or nonsurgical removal?

    PubMed Central

    Girard, R M; Legros, G

    1981-01-01

    An experience with 69 patients who underwent 72 common bile duct reoperations for retained or recurrent choledocholithiasis is presented. The mean age of the patients was 57 years, and 35 patients had associated conditions. In this series six patients (8.3%) had minor complications and no patient developed major complications or died. Two (2.9%) patients developed recurrent choledocholithiasis. In recent years, nonoperative removal of retained stones through a T-tube by mechanical extraction or chemical dissolution, and removal of retained or recurrent stones by endoscopic sphincterotomy has gained widespread popularity. Retained or recurrent choledocholithiasis should be managed on an individual basis. Reoperation has a good success rate, low morbidity and mortality rates. It should be considered as the treatment of choice in low risk patients, in whom a retained stone cannot be mechanically extracted through a T-tube, and in patients with recurrent choledocholithiasis diagnosed after removal of the T-tube. PMID:7469550

  4. 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.

  5. 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.

  6. 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. PMID:26994316

  7. 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

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

    PubMed

    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.

  9. 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

  10. Analysis of stone-column reinforced foundations

    NASA Astrophysics Data System (ADS)

    Lee, J. S.; Pande, G. N.

    1998-12-01

    A numerical model is proposed to analyse elastic as well as elastoplastic behaviour of stone-column reinforced foundations. The stone-columns are assumed to be dispersed within the in situ soil and a homogenization technique is invoked to establish equivalent material properties for in situ soil and stone-column composite. The difficulties encountered in carrying out elastoplastic analyses of composite materials are overcome by adopting a separate yield function for each of the constituent materials and a sub-iteration procedure within an implicit backward Euler stress integration scheme. In the proposed procedure, equilibrium as well as kinematic conditions implied in the homogenization procedure are satisfied for both elastic as well as elastoplastic stress states.The proposed model is implemented in an axi-symmetric finite element code and numerical prediction is made for the behaviour of model circular footings resting on stone-column reinforced foundations. This prediction indicates good agreement with experimental observation. Finally, a new scheme in which the length of stone-column is variable is proposed and its behaviour is examined through a numerical example.

  11. 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

  12. 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

  13. Retained Urethral Catheter Secondary to Placement in Proximal Ureter.

    PubMed

    McGregor, Thomas B; Sharda, Rajan

    2016-01-01

    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter.

  14. Retained Urethral Catheter Secondary to Placement in Proximal Ureter

    PubMed Central

    Sharda, Rajan

    2016-01-01

    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter. PMID:27144050

  15. [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.

  16. 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.

  17. 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.

  18. [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.

  19. 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...

  20. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (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...

  1. 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...

  2. 40 CFR 98.67 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (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...

  3. 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

  4. 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

  5. 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...

  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. 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

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (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...

  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...

  10. 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...

  11. 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

  12. 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

  13. A self-retaining retractor for mitral valve operations.

    PubMed

    Cosgrove, D M

    1986-08-01

    A new self-retaining retractor for mitral valve operations is described. It is universally adjustable, may be affixed to any sternal retractor, and is completely removable when not required for the intracardiac portion of the procedure.

  14. 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

  15. 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

  16. 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

  17. 40 CFR 98.327 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Underground Coal Mines § 98.327 Records that must be retained... for calibration. (b) Records of gas sales. (c) Logbooks of parameter measurements. (d)...

  18. 40 CFR 98.327 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Underground Coal Mines § 98.327 Records that must be retained... for calibration. (b) Records of gas sales. (c) Logbooks of parameter measurements. (d)...

  19. 40 CFR 98.327 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Underground Coal Mines § 98.327 Records that must be retained... for calibration. (b) Records of gas sales. (c) Logbooks of parameter measurements. (d)...

  20. 40 CFR 98.327 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Underground Coal Mines § 98.327 Records that must be retained... for calibration. (b) Records of gas sales. (c) Logbooks of parameter measurements. (d)...

  1. 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...

  2. 40 CFR 98.167 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (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...

  3. 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...

  4. 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...

  5. 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...

  6. 40 CFR 98.427 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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 98.427 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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...

  9. 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...

  10. 40 CFR 98.367 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... addition to the information required by § 98.3(g), you must retain the calibration records for all monitoring equipment, including the method or manufacturer's specification used for calibration....

  11. 15. VIEW LOOKING EAST, SHOWING RETAINING WALL ON EAST SIDE ...

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

    15. VIEW LOOKING EAST, SHOWING RETAINING WALL ON EAST SIDE OF PARK, SOUTH OF ENGINE HOUSE (4' X 5' negative) - Fairmount Waterworks, East bank of Schuylkill River, Aquarium Drive, Philadelphia, Philadelphia County, PA

  12. A technique for relining bar-retained overdentures.

    PubMed

    Mosharraf, Ramin; Abolhasani, Majid; Givehchian, Pirooz

    2014-12-01

    This article describes a technique for relining a mandibular bar-retained overdenture that allows recording the soft tissue beneath the bar and makes it possible to replace or modify the retentive bar attachment simultaneously with the reline procedure.

  13. 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

  14. 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.

  15. 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. PMID:18784007

  16. Optically transparent composites reinforced with plant fiber-based nanofibers

    NASA Astrophysics Data System (ADS)

    Iwamoto, S.; Nakagaito, A. N.; Yano, H.; Nogi, M.

    2005-11-01

    The fibrillation of pulp fiber was attempted by two methods, a high-pressure homogenizer treatment and a grinder treatment. The grinder treatment resulted in the successful fibrillation of wood pulp fibers into nanofibers. The nanofibers demonstrate promising characteristics as reinforcement material for optically transparent composites. Due to the size effect, the nanofiber-reinforced composite retains the transparency of the matrix resin even at high fiber content such as 70 wt %. Since the nanofiber is an aggregate of semi-crystalline extended cellulose chains, its addition also contributes to a significant improvement in the thermal expansion properties of plastics while maintaining its ease of bending. Cellulose nanofibers have tremendous potential as a future resource since they are produced in a sustainable manner by plants, one of the most abundant organic resources on earth.

  17. Reinforcing property of music in Java sparrows (Padda oryzivora).

    PubMed

    Watanabe, S; Nemoto, M

    1998-05-01

    The reinforcing property of music for Java sparrows was examined in a chamber with three perches. One of the end perches produced music by Bach while the other perch produced music by Schoenberg. Two of four birds significantly stayed longer on the perch associated with Bach music and retained their preference of Bach to Schoenberg when other pieces of music by Bach and Schoenberg were used. These two birds also preferred Vivaldi to Carter, suggesting preference for classical music over modern music. One of the two birds that did not show a preference between Bach and Schoenberg preferred Bach to a white noise, but the remaining one did not show any musical preference to noise. These results suggest that Java sparrows have musical preference and that the reinforcing properties depend on individuals. PMID:24896007

  18. 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

  19. Structural Evolution of Silicon Oxynitride Fiber Reinforced Boron Nitride Matrix Composite at High Temperatures

    NASA Astrophysics Data System (ADS)

    Zou, Chunrong; Li, Bin; Zhang, Changrui; Wang, Siqing; Xie, Zhengfang; Shao, Changwei

    2016-02-01

    The structural evolution of a silicon oxynitride fiber reinforced boron nitride matrix (Si-N-Of/BN) wave-transparent composite at high temperatures was investigated. When heat treated at 1600 °C, the composite retained a favorable bending strength of 55.3 MPa while partially crystallizing to Si2N2O and h-BN from the as-received amorphous structure. The Si-N-O fibers still performed as effective reinforcements despite the presence of small pores due to fiber decomposition. Upon heat treatment at 1800 °C, the Si-N-O fibers already lost their reinforcing function and rough hollow microstructure formed within the fibers because of the accelerated decomposition. Further heating to 2000 °C led to the complete decomposition of the reinforcing fibers and only h-BN particles survived. The crystallization and decomposition behaviors of the composite at high temperatures are discussed.

  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. 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…

  2. Positive reinforcement in clinical teaching.

    PubMed

    Gallagher, L M

    1992-01-01

    Contrary to the idea that nursing students are intrinsically motivated, findings in research studies show that students repeatedly report the significance of positive feedback to them. Delivery of positive reinforcement by clinical instructors can be developed so that the reinforcement is more meaningful to students and more effective in promoting or maintaining desired student behaviors.

  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. 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…

  5. 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.

  6. 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…

  7. Reinforcement Schedules and Attributed Freedom.

    ERIC Educational Resources Information Center

    Davidson, Andrew R.; Steiner, Ivan D.

    This study tests the contention that a reinforcing agent's manner of administering rewards and punishments is construed by his associates as revealing his margin of freedom, and that associates are more attentive to cues concerning a reinforcing agent's dispositional qualities, and more inclined to ingratiate themselves to him, when he employes…

  8. 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. PMID:26943741

  9. Physical restraint as positive reinforcement.

    PubMed

    Favell, J E; McGimsey, J F; Jones, M L; Cannon, P R

    1981-01-01

    The reinforcing function of physical restraint was analyzed for three retarded individuals who had a history of restraint and appeared to enjoy it. Using a preference paradigm with one participant and a reversal design with two others, we found that an arbitrary response systematically increased for each participant when followed by brief periods of restraint. No comparable increases occurred in conditions in which responses were not reinforced or were followed by stimuli designed to control for the nonrestraint components of the restraint consequence. Results were discussed in terms of three clinical issues: determining the possible role of restraint in maintaining behavior problems such as self-injury in natural settings, preventing or eliminating the reinforcing function of restraint, and using restraint reinforcement in treating behavior problems when this consequence is the only identifiable reinforcer for an individual.

  10. 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

  11. 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.

  12. Whisker reinforced glass ceramic

    SciTech Connect

    Hirschfeld, D.A.; Brown, J.J. Jr.

    1996-06-03

    The process for making an in-situ whisker reinforced glass-ceramic that is up to 1.5 times as strong as conventional glass-ceramics was developed at Virginia Tech and patented in 1993. This technology has been identified as having commercial potential for use in high temperature heat exchanger applications for the electric power generation field by the National Center for Appropriate Technology (NCAT). This technology was licensed by MATVA, Inc., a small Virginia business, for further development. In particular, the goal of this project was to develop a property database and conduct initial testing of heat exchanger prototypes to demonstrate its potential application. This final report describes how the glass precursor was formed, physical properties of the glass-ceramic, techniques for making heat exchanger prototypes.

  13. 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

  14. 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.

  15. Comparison of retention characteristics of Essix and Hawley retainers

    PubMed Central

    Demir, Abdullah; Nalcacı, Ruhi; Topcuoglu, Tolga

    2012-01-01

    Objective We aimed to compare the retention characteristics of Essix and Hawley retainers. Methods Adolescents undergoing fixed appliance treatment at 2 centers were recruited for this study. Twenty-two patients (16 women and 6 men) wore Essix retainers (Essix group) while 20 (14 women and 6 men) wore Hawley retainers (Hawley group). The mean retention time was 1 year, and the mean follow-up recall time for both groups was 2 years. Two qualified dental examiners evaluated the blind patient data. Maxillary and mandibular dental casts and lateral cephalograms were analyzed at 4 stages: pretreatment (T1), post-treatment (T2), post-retention (T3), and follow-up (T4). Results The results revealed that Essix appliances were more efficient in retaining the anterior teeth in the mandible during a 1-year retention period. The irregularity index increased in both arches in both groups after a 2-year post-retention period. The mandibular arch lengths increased during treatment and tended to return to their original value after retention in both groups; however, these changes were statistically significant only in the Hawley group. Cephalometric variables did not show any significant differences. Conclusions The retention characteristics of both Essix and Hawley retainers are similar. PMID:23173119

  16. Reinforcement, stereotypy, and rule discovery

    PubMed Central

    Steele, David L.; Hayes, Steven C.; Brownstein, Aaron J.

    1990-01-01

    The effects of reinforced pretraining on subsequent rule discovery were examined with college students as subjects. Levels of behavioral stereotypy observed during reinforced and non-contingent pretraining were compared. During pretraining subjects received reinforcement if they pressed two keys in a particular sequence. During the problem session pressing each key four times was a necessary condition for reinforcement, but each problem had additional different requirements for reinforcement. Subjects were asked to solve the problems by discovering the rule that determined whether or not they received reinforcement. Levels of stereotyped responding during pretraining were equivalent for contingently and non-contingently trained subjects. During the problem session contingently pretrained, non-contingently pretrained, and naive subjects required equal numbers of trials to solve problems and solved the same number of problems. The results suggest that behavioral stereotypy observed in this experimental preparation may be due to repeated exposure to the task. Differences between the results observed in this study and that of Schwartz (1982) and implications for the use of reinforcement procedures in applied settings are discussed. PMID:22477604

  17. 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.

  18. 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.

  19. Lead poisoning from retained bullets. Pathogenesis, diagnosis, and management.

    PubMed Central

    Linden, M A; Manton, W I; Stewart, R M; Thal, E R; Feit, H

    1982-01-01

    Lead intoxication (plumbism) from retained bullets has rarely been reported but may be fatal if unrecognized. Bullets lodged within joint spaces or pseudocysts are more likely to develop this complication, although patients with retained missiles in other locations may also be at risk. Subtle findings such as the occurrence of unexplained anemia, abdominal colic, nephropathy, or neurologic deterioration in patients with retained missiles may suggest consideration of plumbism. An intercurrent metabolic stress such as infection, endocrinopathy, or alcoholism may be a precipitating factor. Among the various diagnostic studies available, mass spectrometric stable isotope dilution analysis may be the most reliable. It is important to employ chelation therapy prior to any operative intervention. This will reduce the mobilization of lead from bone during or following the surgical procedure. Images Fig. 1. Fig. 3. Fig. 5. PMID:6800314

  20. Postoperative complications due to a retained surgical sponge.

    PubMed

    Sarda, A K; Pandey, D; Neogi, S; Dhir, U

    2007-06-01

    Retained surgical sponge or glossypiboma is a relatively common occurrence; however, surgeons may not report these events for fear of litigation and adverse publicity. We report postoperative complications in three cases due to retained surgical sponges. The first case, a 26-year-old woman, presented with gastric outlet obstruction due to the sponge obstructing the pyloric canal three weeks following cholecystectomy, which was completely relieved following endoscopical removal of the sponge. The second case, a 32-year-old woman, presented with repeated attacks of intestinal obstruction following cholecystectomy and tubal ligation and was treated with surgical removal of the sponge. The third patient, a 40-year-old woman, presented with features of colonic obstruction following hysterectomy. Colonoscopy revealed a partial migration of the sponge through the colonic wall and on laparotomy, she was found to have multiple internal fistulae between the small and large intestines, all occurring around the inflammation caused by the retained sponge.

  1. 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.

  2. 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. PMID:25945543

  3. 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.

  4. 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

  5. Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane.

    PubMed

    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.

  6. 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

  7. Evaluation of residual strength in the basalt fiber reinforced composites under impact damage

    NASA Astrophysics Data System (ADS)

    Kim, Yun-Hae; Lee, Jin-Woo; Moon, Kyung-Man; Yoon, Sung-Won; Baek, Tae-Sil; Hwang, Kwang-Il

    2015-03-01

    Composites are vulnerable to the impact damage by the collision as to the thickness direction, because composites are being manufactured by laminating the fiber. The understanding about the retained strength after the impact damage of the material is essential in order to secure the reliability of the structure design using the composites. In this paper, we have tried to evaluate the motion of the material according to the kinetic energy and potential energy and the retained strength after impact damage by testing the free fall test of the basalt fiber reinforced composite in the limelight as the environment friendly characteristic.

  8. 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.

  9. 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

  10. 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. PMID:16776058

  11. 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.

  12. 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.

  13. 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.

  14. Detail of staircase (stepped ramp) and retaining wall at West ...

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

    Detail of staircase (stepped ramp) and retaining wall at West 102nd Street, soccer field at right, looking south, with London Plane trees surrounding field. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  15. Structural analysis of a thermal insulation retainer assembly

    NASA Technical Reports Server (NTRS)

    Greene, William H.; Gray, Carl E., Jr.

    1989-01-01

    In January 1989 an accident occurred in the National Transonic Facility wind tunnel at NASA Langley Research Center that was believed to be caused by the failure of a thermal insulation retainer. A structural analysis of this retainer assembly was performed in order to understand the possible failure mechanisms. Two loading conditions are important and were considered in the analysis. The first is the centrifugal force due to the fact that this retainer is located on the fan drive shaft. The second loading is a differential temperature between the retainer assembly and the underlying shaft. Geometrically nonlinear analysis is required to predict the stiffness of this component and to account for varying contact regions between various components in the assembly. High, local stresses develop in the band part of the assembly near discontinuities under both the centrifugal and thermal loadings. The presence of an aluminum ring during a portion of the part's operating life was found to increase the stresses in other regions of the band. Under the centrifugal load, high bending stresses develop near the intersection of the band with joints in the assembly. These high bending stresses are believed to be the most likely cause for failure of the assembly.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 40 CFR 98.47 - 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. 98.47 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...

  2. 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...

  3. 40 CFR 98.47 - 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. 98.47 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...

  4. 40 CFR 98.47 - 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. 98.47 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...

  5. Rheology and retained gas measurements in Hanford tank 101-SY

    SciTech Connect

    Shepard, C.L.; Alzheimer, J.M.; Terrones, G.

    1995-12-31

    Several high-level radioactive waste tanks at the Hanford site are known to produce flammable gases. The best known of these tanks is tank 241-SY-101, and to mitigate the safety concerns associated with flammable gas release from this tank, a mixer pump was installed in mid-1993 to mix the waste contents and thereby eliminate or reduce the capability of the waste to retain gas. The mixer pump has proven very effective and only needs to be operated for 30 min about every other day. Large periodic gas release events no longer occur in this tank. However, specific information about the Theological character of the mixed waste and the amount of retained gas has been lacking. In order to determine the amount of gas still retained in the waste and the rheology of the mixed fluid, which is important in establishing the capability of the waste for retaining gas, two instruments were developed to probe the waste in situ. These instruments were the ball rheometer and the void fraction instrument (VFI).

  6. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (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...

  7. 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...

  8. 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...

  9. 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...

  10. 40 CFR 98.147 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (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...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.67 Records that must be retained. In... information on a monthly basis: (1) Perfluoromethane and perfluoroethane emissions from anode effects in prebake and Sderberg electolysis cells. (2) Anode effect minutes per cell-day (AE-mins/cell-day),...

  12. Portable conduit retention apparatus for releasably retaining a conduit therein

    DOEpatents

    Metzger, R.H.

    1998-07-07

    Portable conduit retention apparatus is described for releasably retaining a conduit therein. The apparatus releasably retains the conduit out of the way of nearby personnel and equipment. The apparatus includes a portable support frame defining a slot therein having an open mouth portion in communication with the slot for receiving the conduit through the open mouth portion and into the slot. A retention bar is pivotally connected to the support frame adjacent the mouth portion for releasably retaining the conduit in the slot. The retention bar freely pivots to a first position, so that the mouth portion is unblocked in order that the conduit is received through the mouth portion and into the slot. In addition, the retention bar freely pivots to a second position, so that the mouth portion is blocked in order that the conduit is retained in the slot. The conduit is released from the slot by pivoting the retention bar to the first position to unblock the mouth portion and thereafter manipulating the conduit from the slot and through the mouth portion. The apparatus may further include a mounting member attached to the support frame for mounting the apparatus on a vertical support surface. Another embodiment of the apparatus includes a shoe assembly of predetermined weight removably connected to the support frame for resting the apparatus on a floor in such a manner that the apparatus is substantially stationary on the floor. 6 figs.

  13. 40 CFR 98.237 - 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. 98.237 Section 98.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems § 98.237 Records that...

  14. 40 CFR 98.357 - 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. 98.357 Section 98.357 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment § 98.357 Records that must...

  15. 40 CFR 98.357 - 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. 98.357 Section 98.357 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment § 98.357 Records that must...

  16. 40 CFR 98.357 - 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. 98.357 Section 98.357 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment § 98.357 Records that must...

  17. 40 CFR 98.357 - 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. 98.357 Section 98.357 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment § 98.357 Records that must...

  18. 40 CFR 98.157 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING HCFC-22 Production and HFC-23 Destruction § 98.157 Records that must be retained. (a) In addition to the data required by § 98.3(g), HCFC-22 production facilities... documenting the initial and periodic calibration of the gas chromatographs, weigh scales, volumetric...

  19. 40 CFR 98.157 - Records that must be retained.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING HCFC-22 Production and HFC-23 Destruction § 98.157 Records that must be retained. (a) In addition to the data required by § 98.3(g), HCFC-22 production facilities... documenting the initial and periodic calibration of the gas chromatographs, weigh scales, volumetric...

  20. 40 CFR 98.97 - 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. 98.97 Section 98.97 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electronics Manufacturing § 98.97 Records that must...

  1. 40 CFR 98.97 - 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. 98.97 Section 98.97 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electronics Manufacturing § 98.97 Records that must...

  2. 49 CFR 240.215 - Retaining information supporting determinations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... driving record; and (4) Any relevant data furnished by the person seeking certification concerning his or... concerning eligibility that the railroad shall retain includes: (1) Any relevant data from the railroad's records concerning the person's prior safety conduct; (2) Any relevant data furnished by another...

  3. 40 CFR 98.407 - 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. 98.407 Section 98.407 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... metered data and showing the calculations of the values used for the missing data. (c) Calculations...

  4. The Retention Factor: Retaining the Distance Education Learner

    ERIC Educational Resources Information Center

    Boyd, Victoria

    2010-01-01

    The purpose of this study is focused upon retaining distance education learners. Many adult learners are returning to higher education but may not complete their chosen curriculum. Fike and Fike (2008) stated that retention is important for a variety of reasons: (a) from the institution's perspective, the retention of students is necessary for…

  5. 4. TURNOUT AND RETAINING WALL AT BASE OF TURTLEBACK DOME. ...

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

    4. TURNOUT AND RETAINING WALL AT BASE OF TURTLEBACK DOME. FACING EAST AT VIEW OF YOSEMITE VALLEY; EL CAPITAN ON LEFT, HALF DOME AT CENTER AND SENTINEL DOME AT LEFT REAR. POST AT LOWER LEFT MARKED 'W3' IS MARKER FOR SELF GUIDED TOUR TO PARK. - Wawona Road, Between South Entrance & Yosemite Valley, Yosemite Village, Mariposa County, CA

  6. 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)

  7. 40 CFR 98.247 - 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. 98.247 Section 98.247 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petrochemical Production § 98.247 Records that must...

  8. 40 CFR 98.337 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (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...

  9. Wear comparison of thermoplastic materials used for orthodontic retainers.

    PubMed

    Gardner, Gary D; Dunn, William J; Taloumis, Louis

    2003-09-01

    Clear thermoplastic retainers are an alternative to fixed lingual retainers and removable Hawley appliances. However, thermoplastic retainers have demonstrated poor wear resistance and durability after only a few months of use. In this study, a simulated wear device was used to compare the wear of different thermoplastic materials used for orthodontic retainers. Three thermoplastic products were evaluated: C+ (Raintree Essix, New Orleans, La),.040-in Invisacryl C (Great Lakes Orthodontics, Towanda, NY), and.040-in TR sheet material (Bay Dental Direct, Bay City, Mich). Twenty specimens were fabricated for each group. The specimens were vacuum thermoformed according to the manufacturers' recommendations and subjected to wear for 1000 cycles in a wear apparatus with steatite ceramic abraders. Depth of wear was determined by surface profilometry. The maximum peak-to-valley measurement was recorded for each specimen. Mean wear (SD) in microns was as follows: C+, 5.9 (2.4); Invisacryl C, 6.1 (2.6); and TR, 1.6 (0.9). One-way analysis of variance detected a significant difference between groups (P <.001). TR material, a hard polyethylene terephthalate glycol copolymer (PETG), demonstrated greater resistance to wear than did the other 2 materials, which were softer, polypropylene-based thermoplastics. There was no evidence to suggest a difference in mean wear between the 2 polypropylene-based materials (P >.05).

  10. 53. Humbug Creek looking downstream from Humbug Diversion Dam. Retaining ...

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

    53. Humbug Creek looking downstream from Humbug Diversion Dam. Retaining wall for canal is visible beginning at left center. Photographer James Eastwood, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  11. 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...

  12. View looking SW at brick retaining wall running parallel to ...

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

    View looking SW at brick retaining wall running parallel to Jones Street showing bricked up storage vaults - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Brick Storage Vaults under Jones Street, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  13. 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…

  14. California's Community Colleges Struggle to Recruit and Retain President

    ERIC Educational Resources Information Center

    Moser, Kate

    2008-01-01

    A year and half has passed since California's Riverside Community College district had a permanent chancellor. Two searches and two interim leaders later, the district's continuing quest for a permanent chancellor reflects a statewide problem of recruiting and retaining two-year-college executives. Smaller applicant pools and many vacant positions…

  15. 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…

  16. 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...

  17. 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...

  18. 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...

  19. 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...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-specific clinker CO2 emission factor. (2) Documentation of quarterly calculated kiln-specific CKD CO2... 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...

  1. 40 CFR 98.407 - 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. 98.407 Section 98.407 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... content or carbon content showing specific industry standards used to develop reporter-specific...

  2. 40 CFR 98.77 - 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. 98.77 Section 98.77 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.77 Records that must be...

  3. 40 CFR 98.437 - 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. 98.437 Section 98.437 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Importers and Exporters of Fluorinated Greenhouse...

  4. 40 CFR 98.417 - 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. 98.417 Section 98.417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.417 Records...

  5. 40 CFR 98.77 - 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. 98.77 Section 98.77 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.77 Records that must be...

  6. 40 CFR 98.417 - 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. 98.417 Section 98.417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.417 Records...

  7. 40 CFR 98.437 - 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. 98.437 Section 98.437 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Importers and Exporters of Fluorinated Greenhouse...

  8. 40 CFR 98.417 - 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. 98.417 Section 98.417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.417 Records...

  9. 40 CFR 98.417 - 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. 98.417 Section 98.417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.417 Records...

  10. 40 CFR 98.57 - 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. 98.57 Section 98.57 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.57 Records that must be...

  11. 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....

  12. 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

  13. 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

  14. 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...

  15. 40 CFR 98.57 - 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. 98.57 Section 98.57 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... in calendar year. (d) Documentation of how accounting procedures were used to estimate...

  16. 40 CFR 98.57 - 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. 98.57 Section 98.57 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... calendar year. (d) Documentation of how accounting procedures were used to estimate production rate....

  17. 40 CFR 98.57 - 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. 98.57 Section 98.57 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... in calendar year. (d) Documentation of how accounting procedures were used to estimate...

  18. Retained Stingray Barb and the Importance of Imaging.

    PubMed

    O'Malley, Gerald F; O'Malley, Rika N; Pham, Oahn; Randolph, Frederick

    2015-09-01

    Stingray envenomation is a common occurrence. X-ray evaluation of stingray wounds is an unnecessarily misunderstood diagnostic concept. We present the case of a patient stung by a stingray with a prolonged and complicated course and permanent disability due to a retained barb. The patient had undergone multiple medical evaluations before an X-ray was obtained. PMID:25937550

  19. 40 CFR 98.257 - 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. 98.257 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...

  20. 40 CFR 98.257 - 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. 98.257 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...

  1. 40 CFR 98.257 - 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. 98.257 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...

  2. 40 CFR 98.257 - 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. 98.257 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...

  3. 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...

  4. 15. VIEW OF DISCHARGE THROUGH SPILLWAY CHUTE FROM WEST RETAINING ...

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

    15. VIEW OF DISCHARGE THROUGH SPILLWAY CHUTE FROM WEST RETAINING WALL, FACING SOUTH. STANDING WAVES ARE VISIBLE. WATER ELEVATION MEASURED 4.8 FEET ABOVE CREST. December 1933 - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA

  5. Cultural Strategies for Retaining Fisheries, Forestries and Land.

    ERIC Educational Resources Information Center

    Paul, Cletus Maanu

    1987-01-01

    Outlines culturally based political and legal strategies used by the indigenous peoples of New Zealand to retain or regain control of fisheries, forests, and land. Emphasizes the need to integrate tribal culture and history into the general education system of New Zealand, thereby underpinning customary tribal rights. (SV)

  6. Portable conduit retention apparatus for releasably retaining a conduit therein

    DOEpatents

    Metzger, Richard H.

    1998-01-01

    Portable conduit retention apparatus for releasably retaining a conduit therein. The apparatus releasably retains the conduit out of the way of nearby personnel and equipment. The apparatus includes a portable support frame defining a slot therein having an open mouth portion in communication with the slot for receiving the conduit through the open mouth portion and into the slot. A retention bar is pivotally connected to the support frame adjacent the mouth portion for releasably retaining the conduit in the slot. The retention bar freely pivots to a first position, so that the mouth portion is unblocked in order that the conduit is received through the mouth portion and into the slot. In addition, the retention bar freely pivots to a second position, so that the mouth portion is blocked in order that the conduit is retained in the slot. The conduit is released from the slot by pivoting the retention bar to the first position to unblock the mouth portion and thereafter manipulating the conduit from the slot and through the mouth portion. The apparatus may further include a mounting member attached to the support frame for mounting the apparatus on a vertical support surface. Another embodiment of the apparatus includes a shoe assembly of predetermined weight removably connected to the support frame for resting the apparatus on a floor in such a manner that the apparatus is substantially stationary on the floor.

  7. An Integrated Approach to Recruiting and Retaining Appalachian Engineering Students

    ERIC Educational Resources Information Center

    Winn, Gary; Hensel, Robin; Curtis, Reagan; Taylor, Lydotta M.; Cilento, Gene

    2012-01-01

    Recruiting and retaining Appalachian engineering students is difficult for a variety of ecological and cultural reasons. At West Virginia University an NSF STEP grant has allowed the development of specific interventions to evolve from an ecological model we describe here. The interventions include web-based, realistic engineering design exercises…

  8. 40 CFR 98.297 - Records that must be retained.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (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)...

  9. 40 CFR 98.297 - Records that must be retained.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (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)...

  10. 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)...

  11. 40 CFR 98.297 - Records that must be retained.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (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)...

  12. 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)...

  13. Retaining Urban Middle School Teachers: An Investigation of Influencing Factors

    ERIC Educational Resources Information Center

    Richardson, JacQueline Elaine

    2012-01-01

    President William Jefferson Clinton is often credited with beginning a new era of improving teacher quality. Since the late 1990's, the federal government has presented a number of reforms that have encouraged states to develop methods to address the revolving door of teachers entering and exiting schools yearly. Retaining teachers has been…

  14. 40 CFR 98.467 - 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. 98.467 Section 98.467 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Waste Landfills § 98.467 Records that must...

  15. On the design of looped orthodontic retainer wires.

    PubMed

    Nikolai, R J; Horner, K D; Blackwell, D A; Carr, R J

    1991-01-01

    Removable Hawley orthodontic retainers have long been prescribed by clinicians following completion of active therapy. Only minor changes have occurred in the design of the retainer over the past 40 years. Structural, in-service failures of this appliance are typically: 1) permanent (inelastic) deformation of the as-prepared labial bow from masticatory action that induces unwanted force transmitted by the appliance to the dentition; or 2) accumulated material damage from removal and replacement of the retainer that eventually results in fracture of the labial bow. This paper reports the results of a series of experimental studies; the overall objective was the optimization of the appliance design, focusing on the labial bow. Wire size, material, temper, canine-loop height, markings for bend placements, heat-treatment of the prepared bow, and two procedures for removing and replacing the appliance were investigated. The collective outcomes suggest a combination of design-parameter values to help maximize the life of the labial bow of the retainer. PMID:1928823

  16. The use of retained patient specimens for haematology quality control.

    PubMed

    Hackney, J R; Cembrowski, G S

    1990-01-01

    Patient blood specimens constitute ideal quality control material in many respects. Although stability is a problem, patient specimens are sufficiently stable to allow their use in the control of short-term systematic error. The principal challenges involve the design of a system which combines excellent performance characteristics (probability of error detection and probability of false rejection) with a minimum of extra work. In the past, guidelines have been presented for an optimized quality control program using retained patient specimens in haematology. These guidelines call for the use of three retained specimens initially analysed only once, with subsequent analyses judged 'out of control' if they deviate from the initial result by a prescribed multiple of the long-term standard deviation. In practice, this system may result in a relatively high probability of false rejection of data (Pfr) due to inadequately established control ranges. Also, the maintenance of three retained patient specimens may be an excessive burden on small laboratories. We present data on the optimization of a quality control program using one retained specimen that is appropriate for use by smaller laboratories. The control rules and the number of initial analyses are adjusted to yield the highest possible probability of error detection (Ped while maintaining a low Pfr and a low additional workload. In addition, we present data concerning the control of satellite instruments by sharing patient specimens between the satellite instrument and a 'reference' instrument.

  17. Retained portion of latex glove during femoral nailing. Case report.

    PubMed

    Sadat-Ali, M; Marwah, S; al-Habdan, I

    1996-11-01

    A case of retained glove during Kuntscher intramedullary nailing is described. An abscess around the glove could have lead to osteomyelitis. One need to be cautious feeling the top end of the nail while femoral nailing to avoid such a complication.

  18. 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...

  19. 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...

  20. 10. Photocopy copy of historic photograph showing retaining wall and ...

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

    10. Photocopy copy of historic photograph showing retaining wall and gabeon of lower dam. Date and photographer unknown. (original in possession of United States Department of Agriculture-Forest Service-Allegheny National Forest) VIEW NORTHEAST - Loleta Recreation Area, Lower Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  1. Find, Attract, and Retain Workers with Affordable Benefits

    ERIC Educational Resources Information Center

    Battersby, Mark E.

    2005-01-01

    Providing benefits to the employees are well-proven motivators. Many child care center owners and directors have discovered that employee benefits can eliminate the need for incentive compensation. This article discusses the importance of fringe benefits to find, attract, and retain workers in a company. It also discusses benefits that employees…

  2. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... account balance. On the business day that the TSC receives an AOC from a retainer or investor depositary, the TSC will credit the depositary's TIP main account balance for the amount reported on the AOC... debited to the reserve account and credited to the TGA. (b) Late delivery of AOC. If an AOC does...

  3. 13. Removal of slide material and construction of stone retaining ...

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

    13. Removal of slide material and construction of stone retaining wall to protect highway. Zion NP negative no. 2084. Photographer: Russell K. Grater, 1941. - Floor of the Valley Road, Between Zion-Mt. Carmel Highway & Temple of Sinawava, Springdale, Washington County, UT

  4. 21 CFR 178.3850 - Reinforced wax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Reinforced wax. 178.3850 Section 178.3850 Food and... and Production Aids § 178.3850 Reinforced wax. Reinforced wax may be safely used as an article or... holding food subject to the provisions of this section. (a) Reinforced wax consists of petroleum wax...

  5. 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. PMID:1890048

  6. Differential reinforcement and signal detection.

    PubMed

    Nevin, J A; Olson, K; Mandell, C; Yarensky, P

    1975-11-01

    Reinforcement was introduced for responses normally treated as errors in signal-detection procedures. The first experiment used a standard two-response discrete-trial procedure with no reinforcement for errors. Results showed that rats altered their response biases but maintained constant sensitivity to visual signals when reinforcement probabilities varied, and that their sensitivity depended on the physical difference between signals, in accordance with the predictions of signal-detection theory. Experiment II, with rats, and Experiment III, with pigeons, demonstrated that sensitivity decreased in this procedure when reinforcement was scheduled for errors with the signals held constant, despite independence of overall number of reinforcers and sensitivity. Experiment IV, with rats, replicated the decrease in sensitivity in a continuous procedure employing only one response. The decrements in sensitivity were similar across Experiments II, III, and IV, and accorded well with earlier research. Thus, contrary to a fundamental assumption of signal-detection theory, estimates of sensitivity are not always invariant with respect to the outcomes of responding, but depend on relative reinforcement of correct responses.

  7. 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.

  8. Methods for producing reinforced carbon nanotubes

    SciTech Connect

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

    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.

  9. 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

  10. Summary report on the design of the retained gas sampler system (retained gas sampler, extruder and extractor)

    SciTech Connect

    Wootan, D.W.; Bolden, R.C.; Bridges, A.E.; Cannon, N.S.; Chastain, S.A.; Hey, B.E.; Knight, R.C.; Linschooten, C.G.; Pitner, A.L.; Webb, B.J.

    1994-09-29

    This document summarizes work performs in Fiscal Year 1994 to develop the three main components of Retained Gas Sampler System (RGSS). These primary components are the Retained Gas Sampler (RGS), the Retained Gas Extruder (RGE), and the Retained Gas Extractor (RGEx). The RGS is based on the Westinghouse Hanford Company (WHC) Universal Sampler design, and includes modifications to reduce gas leakage. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. Significant progress has been made in developing the RGSS. The RGSS is being developed by WHC to extract a representative waste sample from a Flammable Gas Watch List Tanks and to measure both the amount and composition of free and {open_quotes}bound{close_quotes} gases. Sudden releases of flammable gas mixtures are a safety concern for normal waste storage operations and eventual waste retrieval. Flow visualization testing was used to identify important fluid dynamic issues related to the sampling process. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. The safety analysis for the RGSS is being performed by Los Alamos National Laboratory and is more than sixty percent (60%) complete.

  11. Reinforcement of timber beams with carbon fibers reinforced plastics

    NASA Astrophysics Data System (ADS)

    Gugutsidze, G.; Draškovič, F.

    2010-06-01

    Wood is a polymeric material with many valuable features and which also lacks some negative features. In order to keep up with high construction rates and the minimization of negative effects, wood has become one of the most valuable materials in modern engineering. But the use of timber material economically is also an actual problem in order to protect the environment and improve natural surroundings. A panel of scientists is interested in solving these problems and in creating rational structures, where timber can be used efficiently. These constructions are as follows: glue-laminated (gluelam), composed and reinforced wooden constructions. Composed and reinforced wooden constructions are examined less, but according to researches already carried out, it is clear that significant work can be accomplished in creating rational, highly effective and economic timber constructions. The paper deals with research on the formation of composed fiber-reinforced beams (CFRP) made of timber and provide evidence of their effectiveness. The aim of the paper is to investigate cross-bending of CFRP-reinforced gluelaminated timber beams. According to the results we were able to determine the additional effectiveness of reinforcement with CFRP (which depends on the CFRP material's quality, quantity and module of elasticity) on the mechanical features of timber and a whole beam.

  12. Hypodontia, ankylosis and infraocclusion: report of a case restored with a fibre-reinforced ceromeric bridge.

    PubMed

    Sidhu, H K; Ali, A

    2001-12-01

    Retained primary molars without permanent successors often undergo progressive infra-occlusion, without predictable exfoliation. Early prophylactic removal, after assessment of root resorption and adjacent periodontal support loss as well as age of onset, is often indicated. This article describes the joint orthodontic-restorative care of such a case and describes an alternative method of restoration using a fibre-reinforced ceromeric bridge. As well as a conservative preparation and good aesthetics, an overlay restoration provided a fully functional occlusion.

  13. 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.

  14. Positive reinforcement and the elimination of reinforced responses1

    PubMed Central

    Zeiler, Michael D.

    1976-01-01

    Key pecking was maintained on a fixed-interval schedule while either a differential-reinforcement-of-not-responding or a fixed-time schedule was imposed simultaneously. The lower the time parameter of the not-responding schedule, the lower was the response rate. Similar effects occurred with the fixed-time schedule, if the pigeons had experience with reinforcement for not responding. Otherwise the effects were less orderly, to the extent that rate could reach maximum with the lowest-valued fixed-time schedule. The not-responding and the response-independent schedules had similar effects on rate in experienced pigeons only when the time parameter or nominal frequency of food presentation was considered. When considered in terms of obtained frequency of food presentation, reinforcement of not responding produced larger decrements in rate than did the fixed-time schedule. PMID:16811929

  15. Positive reinforcement and the elimination of reinforced responses.

    PubMed

    Zeiler, M D

    1976-07-01

    Key pecking was maintained on a fixed-interval schedule while either a differential-reinforcement-of-not-responding or a fixed-time schedule was imposed simultaneously. The lower the time parameter of the not-responding schedule, the lower was the response rate. Similar effects occurred with the fixed-time schedule, if the pigeons had experience with reinforcement for not responding. Otherwise the effects were less orderly, to the extent that rate could reach maximum with the lowest-valued fixed-time schedule. The not-responding and the response-independent schedules had similar effects on rate in experienced pigeons only when the time parameter or nominal frequency of food presentation was considered. When considered in terms of obtained frequency of food presentation, reinforcement of not responding produced larger decrements in rate than did the fixed-time schedule.

  16. Composites reinforced via mechanical interlocking of surface-roughened microplatelets within ductile and brittle matrices.

    PubMed

    Libanori, R; Carnelli, D; Rothfuchs, N; Binelli, M R; Zanini, M; Nicoleau, L; Feichtenschlager, B; Albrecht, G; Studart, A R

    2016-06-01

    Load-bearing reinforcing elements in a continuous matrix allow for improved mechanical properties and can reduce the weight of structural composites. As the mechanical performance of composite systems are heavily affected by the interfacial properties, tailoring the interactions between matrices and reinforcing elements is a crucial problem. Recently, several studies using bio-inspired model systems suggested that interfacial mechanical interlocking is an efficient mechanism for energy dissipation in platelet-reinforced composites. While cheap and effective solutions are available at the macroscale, the modification of surface topography in micron-sized reinforcing elements still represents a challenging task. Here, we report a simple method to create nanoasperities with tailored sizes and densities on the surface of alumina platelets and investigate their micromechanical effect on the energy dissipation mechanisms of nacre-like materials. Composites reinforced with roughened platelets exhibit improved mechanical properties for both organic ductile epoxy and inorganic brittle cement matrices. Mechanical interlocking increases the modulus of toughness (area under the stress-strain curve) by 110% and 56% in epoxy and cement matrices, respectively, as compared to those reinforced with flat platelets. This interlocking mechanism can potentially lead to a significant reduction in the weight of mechanical components while retaining the structural performance required in the application field. PMID:27070938

  17. Removal of Retained Descemets Membrane Using Femtosecond Laser

    PubMed Central

    May, William; Alrashidi, Sultan; Daoud, Yassine J.

    2016-01-01

    We present a unique method of retrocorneal membrane removal with a femtosecond laser (FSL). A 22-year-old male who had undergone penetrating keratoplasty had a retained retrocorneal membrane and a double anterior chamber postoperatively. The membrane was dissected completely with the FSL and the free-floating membrane was removed. Histopathological evaluation confirmed the diagnosis of retained Descemets membrane (DM). There was improvement in uncorrected visual acuity from 20/300 to 20/50. Central corneal endothelial cell count was 810 cells/mm2 preoperatively and 778 cells/mm2 postoperatively. Inadvertent retention of DM may be safely treated with the FSL. Clarity and viability of the existing graft can be maintained. PMID:27555712

  18. Drill bit assembly for releasably retaining a drill bit cutter

    DOEpatents

    Glowka, David A.; Raymond, David W.

    2002-01-01

    A drill bit assembly is provided for releasably retaining a polycrystalline diamond compact drill bit cutter. Two adjacent cavities formed in a drill bit body house, respectively, the disc-shaped drill bit cutter and a wedge-shaped cutter lock element with a removable fastener. The cutter lock element engages one flat surface of the cutter to retain the cutter in its cavity. The drill bit assembly thus enables the cutter to be locked against axial and/or rotational movement while still providing for easy removal of a worn or damaged cutter. The ability to adjust and replace cutters in the field reduces the effect of wear, helps maintains performance and improves drilling efficiency.

  19. Implant-retained craniofacial prostheses for facial defects

    PubMed Central

    Federspil, Philipp A.

    2012-01-01

    Craniofacial prostheses, also known as epistheses, are artificial substitutes for facial defects. The breakthrough for rehabilitation of facial defects with implant-retained prostheses came with the development of the modern silicones and bone anchorage. Following the discovery of the osseointegration of titanium in the 1950s, dental implants have been made of titanium in the 1960s. In 1977, the first extraoral titanium implant was inserted in a patient. Later, various solitary extraoral implant systems were developed. Grouped implant systems have also been developed which may be placed more reliably in areas with low bone presentation, as in the nasal and orbital region, or the ideally pneumatised mastoid process. Today, even large facial prostheses may be securely retained. The classical atraumatic surgical technique has remained an unchanged prerequisite for successful implantation of any system. This review outlines the basic principles of osseointegration as well as the main features of extraoral implantology. PMID:22073096

  20. Neurochemical substrates for opiate reinforcement.

    PubMed

    Koob, G F; Vaccarino, F J; Amalric, M; Bloom, F E

    1986-01-01

    The studies reported herein summarize our work to date aimed at determining the neurochemical substrates for the reinforcing properties of opiates. Rats were trained to self-administer heroin intravenously in daily 3-hour sessions, and pharmacological blockade and neurotoxin-induced lesions were used to define the neurochemical substrates for this reinforcing action. Low-dose DA receptor blockade failed to alter heroin self-administration but significantly increased cocaine self-administration, presumably reflecting a decrease in the reinforcing effectiveness of cocaine. Destruction of presynaptic DA terminals within the N.Acc. produced extinction of cocaine, but not heroin, self-administration. Opiate receptor blockade with systemic naloxone increased heroin, but not cocaine, self-administration. Methylnaloxonium injections into the N.Acc. were effective in increasing heroin self-administration at doses one-eighth those observed for intracerebroventricular injections. Reinforcement has been explored using a place-preference procedure and a self-administration drug-substitution paradigm. Mu/delta agonists such as B-END readily produce a naloxone-reversible place preference. Fentanyl derivatives also produce place preference and substitute for heroin during self-administration. The kappa agonist U50-488 produces place aversion, not place preference, and does not readily substitute for heroin. Altogether, these results suggest that mu/delta receptor subtypes in the region of the N.Acc. may be an important neurochemical substrate for opiate reinforcement.

  1. 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.

  2. 12. A VIEW LOOKING EAST, FROM ATOP THE RETAINING WALL ...

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

    12. A VIEW LOOKING EAST, FROM ATOP THE RETAINING WALL ON THE NORTHEAST ABUTMENT PROVIDES A COMPANION VIEW TO THE PREVIOUS PHOTOGRAPH. THE CLUB HOUSE, PORTIONS OF THE BOARDWALK, A PICNIC SHELTER AND THE SWIMMING STEPS ARE VISIBLE, ALONG WITH A PORTION OF THE NINETEENTH CENTURY BUILDING ON THE NORTH BANK WHICH IS NOW HOME TO COMMERCIAL ENDEAVORS - Delphi Bridge on U.S. Route 421, Spanning Deer Creek at U.S. Route 421, Delphi, Carroll County, IN

  3. Sodium-retaining effect of insulin in diabetes

    PubMed Central

    Manhiani, M. Marlina

    2012-01-01

    Insulin has long been hypothesized to cause sodium retention, potentially of enough magnitude to contribute to hypertension in obesity, metabolic syndrome, and Type II diabetes. There is an abundance of supportive evidence from correlational analyses in humans, acute insulin infusion studies in humans and animals, and chronic insulin infusion studies in rats. However, the absence of hypertension in human insulinoma patients, and negative results for sodium-retaining or blood pressure effects of chronic insulin infusion in a whole series of dog studies, strongly refute the insulin hypothesis. We recently questioned whether the euglycemic, hyperinsulinemia model used for most insulin infusion studies, including the previous chronic dog studies, was the most appropriate model to test the renal actions of insulin in obesity, metabolic syndrome, and Type II diabetes. In those circumstances, hyperinsulinemia coexists with hyperglycemia. Therefore, we tested the sodium-retaining effect of insulin in chronically instrumented, alloxan-treated diabetic dogs. We used 24 h/day intravenous insulin infusion to regulate plasma insulin concentration. Induction of diabetes (∼400 mg/dl) caused sustained natriuresis and diuresis. However, if we clamped insulin at baseline, control levels, i.e., prevented it from decreasing, then the sustained natriuresis and diuresis were completely reversed, despite the same level of hyperglycemia. We also found that 24 h/day intrarenal insulin infusion had the same effect in diabetic dogs but had no sodium-retaining action in normal dogs. This new evidence that insulin has a sodium-retaining effect during hyperglycemia may have implications for maintaining sodium balance in uncontrolled Type II diabetes. PMID:23034715

  4. Analysis of Embedded Retaining Wall Using the Subgrade Reaction Method

    NASA Astrophysics Data System (ADS)

    Pasik, Tomasz; Chalecki, Marek; Koda, Eugeniusz

    2015-03-01

    This paper analyzes the distribution of internal forces and displacements of embedded retaining wall in Quaternary deposits and Tertiary clays. Calculations have been based on the Subgrade Reaction Method (SRM) for two different types of earth pressure behind the wall (active, at-rest) in order to show the differences resulting from adopting the limit values. An algorithm for calculation of "cantilever wall" using the Mathematica program was proposed.

  5. Method for residual stress relief and retained austenite destabilization

    DOEpatents

    Ludtka, Gerard M.

    2004-08-10

    A method using of a magnetic field to affect residual stress relief or phase transformations in a metallic material is disclosed. In a first aspect of the method, residual stress relief of a material is achieved at ambient temperatures by placing the material in a magnetic field. In a second aspect of the method, retained austenite stabilization is reversed in a ferrous alloy by applying a magnetic field to the alloy at ambient temperatures.

  6. Water-retaining barrier and method of construction

    DOEpatents

    Adams, M.R.; Field, J.G.

    1996-02-20

    An agricultural barrier is disclosed which provides a medium for supporting plant life in an arid or semi-arid land region having a ground surface. The barrier is disposed on native soil of the region. The barrier includes a first porous layer composed of pieces of basalt, and is in contact with the native soil. There is a less porous second layer of at least one material selected from at least one of sand and gravel. The second layer overlies the first layer. A third layer, less porous than the second layer, contains soil which favors plant growth. The third layer overlies the second layer and has an exposed upper surface. The porosities of the second and third layers differ from one another by an amount which impedes transport of soil from the first layer into the second layer. Soil for the third layer may be provided by washing salinated or contaminated soil with water and using the washed soil for the third layer. 2 figs.

  7. Water-retaining barrier and method of construction

    DOEpatents

    Adams, Melvin R.; Field, Jim G.

    1996-01-01

    An agricultural barrier providing a medium for supporting plant life in an arid or semi-arid land region having a ground surface, the barrier being disposed on native soil of the region, the barrier including: a first layer composed of pieces of basalt, the first layer being porous and being in contact with the native soil; a porous second layer of at least one material selected from at least one of sand and gravel, the second layer being less porous than, and overlying, the first layer; and a porous third layer containing soil which favors plant growth, the third layer being less porous than, and overlying, the second layer and having an exposed upper surface, wherein the porosities of the second and third layers differ from one another by an amount which impedes transport of soil from the first layer into the second layer. Soil for the third layer may be provided by washing salinated or contaminated soil with water and using the washed soil for the third layer.

  8. 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

  9. 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.

  10. A survey of failed post-retained restorations

    PubMed Central

    Sahafi, A.; Asmussen, E.

    2007-01-01

    Survival of endodontically treated, post-restored teeth depends on a multitude of factors, all of which are practically impossible to include in a randomized, controlled clinical study. The purpose of this survey was to characterize and analyze reported failures of post-retained restorations to identify factors critical to failure and to type of failure. A questionnaire was mailed to private practitioners in Denmark with a request to complete the questionnaire whenever a patient presented with a failed post-retained restoration. Information was gathered on factors related to the patient, the tooth, the restorative materials, and the techniques. Two-hundred and sixty questionnaires were collected from 171 practitioners over a 3-year period. Functioning time until failure varied between 3 months and 38 years. Mean survival time until failure was 11 years. Of the failed restorations, 61% had functioned for 10 years or less. Fracture of the tooth was the most common type of failure reported, followed by loosening of the post and fracture of the post. Tapered posts implied an increased risk of tooth fracture compared to loosening or fracture of the post, and the relative risk of tooth fracture increased with the functioning time until failure. Fracture of the post was more common among male than female patients. On the basis of this survey of failed post-retained restorations, it was concluded that tapered posts were associated with a higher risk of tooth fracture than were parallel-sided posts. PMID:17636353

  11. Engaging and Retaining Abused Women in Perinatal Home Visitation Programs

    PubMed Central

    Alhusen, Jeanne L.; Bullock, Linda; Bhandari, Shreya; Ghazarian, Sharon; Udo, Ifeyinwa E.; Campbell, Jacquelyn

    2013-01-01

    OBJECTIVES: Intimate partner violence (IPV) during pregnancy affects 0.9% to 17% of women and affects maternal health significantly. The impact of IPV extends to the health of children, including an increased risk of complications during pregnancy and the neonatal period, mental health problems, and cognitive delays. Despite substantial sequelae, there is limited research substantiating best practices for engaging and retaining high-risk families in perinatal home visiting (HV) programs, which have been shown to improve infant development and reduce maltreatment. METHODS: The Domestic Violence Enhanced Home Visitation Program (DOVE) is a multistate longitudinal study testing the effectiveness of a structured IPV intervention integrated into health department perinatal HV programs. The DOVE intervention, based on an empowerment model, combined 2 evidence-based interventions: a 10-minute brochure-based IPV intervention and nurse home visitation. RESULTS: Across all sites, 689 referrals were received from participating health departments. A total of 339 abused pregnant women were eligible for randomization; 42 women refused, and 239 women were randomly assigned (124 DOVE; 115 usual care), resulting in a 71% recruitment rate. Retention rates from baseline included 93% at delivery, 80% at 3 months, 76% at 6 months, and 72% at 12 months. CONCLUSIONS: Challenges for HV programs include identifying and retaining abused pregnant women in their programs. DOVE strategies for engaging and retaining abused pregnant women should be integrated into HV programs’ federal government mandates for the appropriate identification and intervention of women and children exposed to IPV. PMID:24187115

  12. Hybrid Approach to Reinforcement Learning

    NASA Astrophysics Data System (ADS)

    Boulebtateche, Brahim; Fezari, Mourad; Boughazi, Mohamed

    2008-06-01

    Reinforcement Learning (RL) is a general framework in which an autonomous agent tries to learn an optimal policy of actions from direct interaction with the surrounding environment (RL). However, one difficulty for the application of RL control is its slow convergence, especially in environments with continuous state space. In this paper, a modified structure of RL is proposed to speed up reinforcement learning control. In this approach, supervision technique is combined with the standard Q-learning, a model-free algorithm of reinforcement learning. The a priori information is provided to the RL by an optimal LQ-controller, used to indicate preferred actions at intermittent times. It is shown that the convergence speed of the supervised RL agent is greatly improved compared to the conventional Q-Learning algorithm. Simulation work and results on the cart-pole balancing problem are given to illustrate the efficiency of the proposed method.

  13. Microwave NDE for Reinforced Concrete

    NASA Astrophysics Data System (ADS)

    Arunachalam, Kavitha; Melapudi, Vikram R.; Rothwell, Edward J.; Udpa, Lalita; Udpa, Satish S.

    2006-03-01

    Nondestructive assessment of the integrity of civil structures is of paramount importance for ensuring safety. In concrete imaging, radiography, ground penetrating radar and infrared thermography are some of the widely used techniques for health monitoring. Other emerging technologies that are gaining impetus for detecting and locating flaws in steel reinforcement bar include radioactive computed tomography, microwave holography, microwave and acoustic tomography. Of all the emerging techniques, microwave NDT is a promising imaging modality largely due to their ability to penetrate thick concrete structures, contrast between steel rebar and concrete and their non-radioactive nature. This paper investigates the feasibility of a far field microwave NDE technique for reinforced concrete structures.

  14. 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…

  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. FEM evaluation of cemented-retained versus screw-retained dental implant single-tooth crown prosthesis

    PubMed Central

    Cicciu, Marco; Bramanti, Ennio; Matacena, Giada; Guglielmino, Eugenio; Risitano, Giacomo

    2014-01-01

    Prosthetic rehabilitation of partial or total edentulous patients is today a challenge for clinicians and dental practitioners. The application of dental implants in order to recover areas of missing teeth is going to be a predictable technique, however some important points about the implant angulation, the stress distribution over the bone tissue and prosthetic components should be well investigated for having final long term clinical results. Two different system of the prosthesis fixation are commonly used. The screw retained crown and the cemented retained one. All of the two restoration techniques give to the clinicians several advantages and some disadvantages. Aim of this work is to evaluate all the mechanical features of each system, through engineering systems of investigations like FEM and Von Mises analyses. The FEM is today a useful tool for the prediction of stress effect upon material and biomaterial under load or strengths. Specifically three different area has been evaluated through this study: the dental crown with the bone interface; the passant screw connection area; the occlusal surface of the two different type of crown. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed an adequate response for both type of prostheses, although cemented retained one showed better results over the occlusal area. PMID:24955150

  17. FEM evaluation of cemented-retained versus screw-retained dental implant single-tooth crown prosthesis.

    PubMed

    Cicciu, Marco; Bramanti, Ennio; Matacena, Giada; Guglielmino, Eugenio; Risitano, Giacomo

    2014-01-01

    Prosthetic rehabilitation of partial or total edentulous patients is today a challenge for clinicians and dental practitioners. The application of dental implants in order to recover areas of missing teeth is going to be a predictable technique, however some important points about the implant angulation, the stress distribution over the bone tissue and prosthetic components should be well investigated for having final long term clinical results. Two different system of the prosthesis fixation are commonly used. The screw retained crown and the cemented retained one. All of the two restoration techniques give to the clinicians several advantages and some disadvantages. Aim of this work is to evaluate all the mechanical features of each system, through engineering systems of investigations like FEM and Von Mises analyses. The FEM is today a useful tool for the prediction of stress effect upon material and biomaterial under load or strengths. Specifically three different area has been evaluated through this study: the dental crown with the bone interface; the passant screw connection area; the occlusal surface of the two different type of crown. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed an adequate response for both type of prostheses, although cemented retained one showed better results over the occlusal area. PMID:24955150

  18. Fit-for-purpose phosphorus management: do riparian buffers qualify in catchments with sandy soils?

    PubMed

    Weaver, David; Summers, Robert

    2014-05-01

    Hillslope runoff and leaching studies, catchment-scale water quality measurements and P retention and release characteristics of stream bank and catchment soils were used to better understand reasons behind the reported ineffectiveness of riparian buffers for phosphorus (P) management in catchments with sandy soils from south-west Western Australia (WA). Catchment-scale water quality measurements of 60 % particulate P (PP) suggest that riparian buffers should improve water quality; however, runoff and leaching studies show 20 times more water and 2 to 3 orders of magnitude more P are transported through leaching than runoff processes. The ratio of filterable reactive P (FRP) to total P (TP) in surface runoff from the plots was 60 %, and when combined with leachate, 96 to 99 % of P lost from hillslopes was FRP, in contrast with 40 % measured as FRP at the large catchment scale. Measurements of the P retention and release characteristics of catchment soils (<2 mm) compared with stream bank soil (<2 mm) and the <75-μm fraction of stream bank soils suggest that catchment soils contain more P, are more P saturated and are significantly more likely to deliver FRP and TP in excess of water quality targets than stream bank soils. Stream bank soils are much more likely to retain P than contribute P to streams, and the in-stream mixing of FRP from the landscape with particulates from stream banks or stream beds is a potential mechanism to explain the change in P form from hillslopes (96 to 99 % FRP) to large catchments (40 % FRP). When considered in the context of previous work reporting that riparian buffers were ineffective for P management in this environment, these studies reinforce the notion that (1) riparian buffers are unlikely to provide fit-for-purpose P management in catchments with sandy soils, (2) most P delivered to streams in sandy soil catchments is FRP and travels via subsurface and leaching pathways and (3) large catchment-scale water quality measurements

  19. What is a "schedule of reinforcement"?

    PubMed

    Schoenfeld, W N; Cole, B K

    1975-01-01

    Several ambiguities in the present terminology of behavior theory obscure some important theoretical assumptions and experimental details in current research. Left unclarified, such ambiguities impede the accurate analysis of laboratory procedures, and prevent reliable communication among researchers. This paper focuses on the term "schedule of reinforcement". It points out that two distinguishable operational rules are implicated in the term: in the case where reinforcement is of the so-called response contingent type, the "schedule" is really a rule to identify the response to be reinforced; in the case of non-contingent reinforcement, the "schedule" is truly a rule for delivery of reinforcement. Other terminological ambiguities that are encountered in a discussion of this term include "reinforcement" and "intermittency." A resolution of these problems will necessarily involve the procedures of non-contingent reinforcement, and the parameter of reinforcement probability.

  20. Choice, conditioned reinforcement, and the prius effect.

    PubMed

    Fantino, Edmund

    2008-01-01

    Psychologists have long been intrigued with the rationales that underlie our decisions. Similarly, the concept of conditioned reinforcement has a venerable history, particularly in accounting for behavior not obviously maintained by primary reinforcers. The studies of choice and of conditioned reinforcement have often developed in lockstep. Many contemporary approaches to these fundamental topics share an emphasis on context and on relative value. We trace the evolution of thinking about the potency of conditioned reinforcers from stimuli that were thought to acquire their value from pairings with more fundamental reinforcers to stimuli that acquire their value by being differentially correlated with these more fundamental reinforcers. We discuss some seminal experiments (including several that have been underappreciated) and some ongoing data, all of which have propelled us to the conclusion that the strength of conditioned reinforcers is determined by their signaling a relative improvement in the organism's relation to reinforcement.

  1. Reinforcement learning in supply chains.

    PubMed

    Valluri, Annapurna; North, Michael J; Macal, Charles M

    2009-10-01

    Effective management of supply chains creates value and can strategically position companies. In practice, human beings have been found to be both surprisingly successful and disappointingly inept at managing supply chains. The related fields of cognitive psychology and artificial intelligence have postulated a variety of potential mechanisms to explain this behavior. One of the leading candidates is reinforcement learning. This paper applies agent-based modeling to investigate the comparative behavioral consequences of three simple reinforcement learning algorithms in a multi-stage supply chain. For the first time, our findings show that the specific algorithm that is employed can have dramatic effects on the results obtained. Reinforcement learning is found to be valuable in multi-stage supply chains with several learning agents, as independent agents can learn to coordinate their behavior. However, learning in multi-stage supply chains using these postulated approaches from cognitive psychology and artificial intelligence take extremely long time periods to achieve stability which raises questions about their ability to explain behavior in real supply chains. The fact that it takes thousands of periods for agents to learn in this simple multi-agent setting provides new evidence that real world decision makers are unlikely to be using strict reinforcement learning in practice.

  2. Brucite nanoplate reinforced starch bionanocomposites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper the mechanical reinforcement in a series of bionanocomposites films based on starch and nano-sized brucite, Mg(OH)2, was investigated. Brucite nanoplates with an aspect ratio of 9.25 were synthesized by wet precipitation and incorporated into starch matrices at different concentrations...

  3. Fiber reinforced PMR polyimide composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.; Winters, W. E.

    1978-01-01

    Commercially obtained PMR-15 polyimide prepregs with S-glass and graphite fiber reinforcements were evaluated along with in-house prepared glass and graphite cloth PMR 2 materials. A novel autoclave approach was conceived and used to demonstrate that both the PMR systems respond to 1.4 MPa (200 psi) autoclave pressures to produce void free composites equivalent to die molded laminates. Isothermal gravimetric analysis and subsequent mechanical property tests indicated that the PMR 2 system was significantly superior in thermo-oxidative stability, and that S-glass reinforcements may contribute to the accelerated degradation of composites at 316 C (600 F) when compared to graphite fiber reinforced composites. Fully reversed bending fatigue experiments were conducted with a type of fixture unused for organic matrix composites. These studies indicated that the graphite fiber composites were clearly superior in fatigue resistance to the glass fiber reinforced material and that PMR matrix composite systems yield performance of the same order as composite materials employing other families of matrices.

  4. Stimuli, Reinforcers, and Private Events

    ERIC Educational Resources Information Center

    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…

  5. Interprofessional simulation of a retained placenta and postpartum hemorrhage.

    PubMed

    Phillippi, Julia C; Buxton, Margaret; Overstreet, Maria

    2015-07-01

    To improve quality and safety in healthcare, national and international organizations have called for students to receive dedicated training in interprofessional communication and collaboration. We developed a simulation for nurse-midwifery and nurse-anesthesia students, using the Core Competencies for Interprofessional Collaborative Practice framework. The simulation, involving a postpartum women with a retained placenta and acute blood loss, allowed students to collaboratively manage a high-risk situation. We present the details of the simulation and evaluation to assist educators. PMID:25707310

  6. Retaining space and time coherence in radiative transfer models.

    PubMed

    Rosato, J

    2015-05-01

    A recent model for radiative transfer that accounts for spatial coherence is extended in such a way as to retain temporal coherence. The method employs Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy techniques. Both spatial and temporal coherence are shown to affect the formation of atomic line spectra. Calculations of Lyman α radiation transport in optically thick divertor plasma conditions are reported as an illustration of the model. A possible extension of the formalism to dense media involving correlations between atoms is discussed in an appendix. A link to partial frequency redistribution modeling is also discussed.

  7. Retained Contrast After Embolization of a Right Gastric Artery Pseudoaneurysm

    SciTech Connect

    Winick, Adam B.; Malloy, Patrick C.; Lund, Gunnar B.

    1996-11-15

    Pseudoaneurysms due to chronic pancreatitis can be a source of major gastrointestinal (GI) hemorrhage. Computed tomography (CT) is the primary diagnostic imaging modality for pancreatic pseudocysts associated with GI bleeding. Pseudoaneurysms and associated GI bleeding can be diagnosed and embolized with transcatheter techniques once the arterial anatomy is defined. CT is a useful modality for follow-up examination of the pseudocyst; the findings must be correlated with other procedures performed on these patients. On follow-up studies, contrast medium retained in the pseudocyst after embolization may falsely signal persistent bleeding into the pseudocyst.

  8. Porous electrolyte retainer for molten carbonate fuel cell. [lithium aluminate

    DOEpatents

    Singh, R.N.; Dusek, J.T.

    1979-12-27

    A porous tile for retaining molten electrolyte within a fuel cell is prepared by sintering particles of lithium aluminate into a stable structure. The tile is assembled between two porous metal plates which serve as electrodes with fuels gases such as H/sub 2/ and CO opposite to oxidant gases such as O/sub 2/ and CO/sub 2/. The tile is prepared with a porosity of 55 to 65% and a pore size distribution selected to permit release of sufficient molten electrolyte to wet but not to flood the adjacent electrodes.

  9. Porous electrolyte retainer for molten carbonate fuel cell

    DOEpatents

    Singh, Raj N.; Dusek, Joseph T.

    1983-06-21

    A porous tile for retaining molten electrolyte within a fuel cell is prepared by sintering particles of lithium aluminate into a stable structure. The tile is assembled between two porous metal plates which serve as electrodes with fuels gases such as H.sub.2 and CO opposite to oxidant gases such as O.sub.2 and CO.sub.2. The tile is prepared with a porosity of 55-65% and a pore size distribution selected to permit release of sufficient molten electrolyte to wet but not to flood the adjacent electrodes.

  10. Autofrettage: Stress distribution under load and retained stresses after depressurization

    NASA Astrophysics Data System (ADS)

    Avitzur, Boaz

    1992-07-01

    There is a long-standing interest in developing a capability to predict the distribution of retained stresses in thick-walled tubes after the removal of an internal pressure-post autofrettage. In this report, four different methods of calculating such stresses are presented and compared. The methods presented are based on the following assumed yield criteria and deformation conditions: (1) Tresca's yield criterion; (2) Tresca's yield criterion 2/3; (3) Mises' yield criterion in plane-stress; and (4) Mises' yield criterion in plane-strain.

  11. 6. "TEST STAND NO. 13, RETAINING WALLS & APRON, SECTIONS ...

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

    6. "TEST STAND NO. 1-3, RETAINING WALLS & APRON, SECTIONS & ELEVATIONS." Specifications No. OC11-50-10; Drawing No. 60-09-06; no sheet number within title block. D.O. SERIES 1109/20, Rev. B. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04-353 Eng. 177, Rev. B; Date: 26 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-3, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  12. To forget is human: the case of the retained bulb.

    PubMed

    Sakhel, Khaled; Hines, James

    2009-03-01

    The scenario of a forgotten instrument or foreign body has plagued surgical procedures from the early days. It has been estimated that the incidence of retained foreign bodies is around one in every 1,000-1,500 intra-abdominal operations and can be expected to occur at least once per year in hospitals where 8,000-18,000 major surgeries are performed annually. We report a case of a forgotten asepto bulb in the vagina following a robot-assisted total laparoscopic hysterectomy. PMID:27628453

  13. OBSERVABLE CHANGES OF HYPOTHESES UNDER POSITIVE REINFORCEMENT.

    PubMed

    SUPPES, P; SCHLAG-REY, M

    1965-04-30

    In mathematical models of concept learning it has consistently been assumed that positive reinforcement cannot lead to a change of the hypothesis determining the overt response. When hypotheses are experimentally identified and recorded along with positive and negative reinforcements of stimulus-response pairs, it can be shown that hypotheses may change after a positive reinforcement. Positive reinforcement has an information content for subjects that has not yet been adequately recognized in concept formation studies.

  14. Positive Reinforcement and Response Cost Procedures in a Token Reinforcement Program in a Special Education Class.

    ERIC Educational Resources Information Center

    Eisen, Lynne G.; Eisen, Marvin

    Compared in a junior high class of 12 educable mentally handicapped children were the effects on adaptive behaviors of a token reinforcement program involving only positive reinforcement and a token reinforcement program additionally involving response cost. The token reinforcement response cost condition allowed students to earn points for…

  15. Conditioned Reinforcement Value and Resistance to Change

    ERIC Educational Resources Information Center

    Shahan, Timothy A.; Podlesnik, Christopher A.

    2008-01-01

    Three experiments examined the effects of conditioned reinforcement value and primary reinforcement rate on resistance to change using a multiple schedule of observing-response procedures with pigeons. In the absence of observing responses in both components, unsignaled periods of variable-interval (VI) schedule food reinforcement alternated with…

  16. Stimulus properties of reinforcing brain shock.

    PubMed

    Stutz, R M; Butcher, R E; Rossi, R

    1969-03-01

    Rats easily discriminate between two types of subcortical brain shock which differ in reinforcing properties. When both stimuli are either neutral or positively reinforcing subjects have difficulty in responding differentially to the two types of electrical stimulation of the brain. Possible implications for a theory concerning a generalized or diffuse reinforcement system are discussed.

  17. Applied Implications of Reinforcement History Effects

    ERIC Educational Resources Information Center

    Pipkin, Claire St. Peter; Vollmer, Timothy R.

    2009-01-01

    Although the influence of reinforcement history is a theoretical focus of behavior analysis, the specific behavioral effects of reinforcement history have received relatively little attention in applied research and practice. We examined the potential effects of reinforcement history by reviewing nonhuman, human operant, and applied research and…

  18. Rational and Mechanistic Perspectives on Reinforcement Learning

    ERIC Educational Resources Information Center

    Chater, Nick

    2009-01-01

    This special issue describes important recent developments in applying reinforcement learning models to capture neural and cognitive function. But reinforcement learning, as a theoretical framework, can apply at two very different levels of description: "mechanistic" and "rational." Reinforcement learning is often viewed in mechanistic terms--as…

  19. A Novel Reinforcer System: Teacher Idea Exchange.

    ERIC Educational Resources Information Center

    Raschke, Donna; And Others

    1988-01-01

    The "PEZ" candy dispenser has been used effectively to deliver reinforcers to moderately handicapped preschool students who display desirable behaviors. Contingency management procedures are described for using the candy dispenser to deliver reinforcers and subsequently to fade out the edible reinforcer and have the colorful dispenser itself…

  20. Practicing Positive Reinforcement: Ten Behavior Management Techniques.

    ERIC Educational Resources Information Center

    McDaniel, Thomas R.

    1987-01-01

    Presents practical techniques teachers can use for classroom management: (1) teach specific directions, (2) look for good behavior, (3) praise effectively, (4) model good behavior, (5) use nonverbal reinforcement, (6) establish token economies, (7) "premack" (students determine reinforcers for appropriate behavior), (8) teach kids to reinforce one…

  1. Stem cell programs are retained in human leukemic lymphoblasts.

    PubMed

    Fan, D; Zhou, X; Li, Z; Li, Z-Q; Duan, C; Liu, T; Zhang, F; Huang, Y; Zhang, Y; Gao, F; Guo, Y; Gupta, R; Chen, G; Enver, T; Tang, J; Hong, D

    2015-04-16

    Leukemic lymphoblasts within different immunophenotypic populations possess stem cell properties. However, whether or not the self-renewal program is retained from stem cells or conferred on progenitors by leukemogenic molecules remains unknown. We have addressed the issue in the context of TEL-AML1-associated acute lymphoblastic leukemia (ALL) by profiling a refined program edited from genes essential for self-renewal of hematopoietic stem cells and B-cell development. Bioinformatic analysis shows that ALL populations are loosely clustered and close to the normal population that contains stem and primitive progenitor cells. This finding indicates that immunophenotypes do not reflect maturation stages in ALL and that the self-renewal program may be retained from stem cells. Results of assessing 'first hit' function of TEL-AML1 in different populations of normal cells demonstrate the molecular model. Therefore, the current study shows a leukemogenic scenario of human ALL in which programs of stem cells are sustained in distinct fractions by leukemogenic mutations.

  2. Are forensic experts biased by the side that retained them?

    PubMed

    Murrie, Daniel C; Boccaccini, Marcus T; Guarnera, Lucy A; Rufino, Katrina A

    2013-10-01

    How objective are forensic experts when they are retained by one of the opposing sides in an adversarial legal proceeding? Despite long-standing concerns from within the legal system, little is known about whether experts can provide opinions unbiased by the side that retained them. In this experiment, we paid 108 forensic psychologists and psychiatrists to review the same offender case files, but deceived some to believe that they were consulting for the defense and some to believe that they were consulting for the prosecution. Participants scored each offender on two commonly used, well-researched risk-assessment instruments. Those who believed they were working for the prosecution tended to assign higher risk scores to offenders, whereas those who believed they were working for the defense tended to assign lower risk scores to the same offenders; the effect sizes (d) ranged up to 0.85. The results provide strong evidence of an allegiance effect among some forensic experts in adversarial legal proceedings. PMID:23969777

  3. Fracture resistance of weakened roots restored with different intracanal retainers.

    PubMed

    Broch, Juliana; Marchionatti, Ana Maria Estivalete; Bergoli, Cesar Dalmolin; Valandro, Luiz Felipe; Kaizer, Osvaldo Bazzan

    2015-01-01

    The purposes of the study were to evaluate the effect of mechanical cycling (MC) on the fracture resistance of endodontically treated weakened roots restored with different intraradicular retainers and to analyze the failure mode. Eighty bovine roots were prepared and restored: 20 roots were reconstructed with cast post-and-cores (CPCs); 20 with fiber posts (FPs); 20 with fiber posts with larger coronal diameter (FPLs); and 20 with anatomic posts (APs). Metal crowns were cemented in all the roots. Half of specimens from each restoration strategy (n = 10) were submitted to MC: CPC-MC, FP-MC, FPL-MC, and AP-MC. The specimens were subjected to a fracture resistance test. The results showed that the type of retainer used was statistically significant (P < 0.0004). The CPC specimens demonstrated a fracture resistance similar to that of the APs, but greater than that of the FPs and FPLs. MC was statistically significant (P < 0.003) and affected AP-MC fracture resistance, which was lower than that of CPC-MC and similar to those of FP-MC and FPL-MC.

  4. Retained austenite thermal stability in a nanostructured bainitic steel

    SciTech Connect

    Avishan, Behzad; Garcia-Mateo, Carlos; Yazdani, Sasan; Caballero, Francisca G.

    2013-07-15

    The unique microstructure of nanostructured bainite consists of very slender bainitic ferrite plates and high carbon retained austenite films. As a consequence, the reported properties are opening a wide range of different commercial uses. However, bainitic transformation follows the T{sub 0} criteria, i.e. the incomplete reaction phenomena, which means that the microstructure is not thermodynamically stable because the bainitic transformation stops well before austenite reaches an equilibrium carbon level. This article aims to study the different microstructural changes taking place when nanostructured bainite is destabilized by austempering for times well in excess of that strictly necessary to end the transformation. Results indicate that while bainitic ferrite seems unaware of the extended heat treatment, retained austenite exhibits a more receptive behavior to it. - Highlights: • Nanostructured bainitic steel is not thermodynamically stable. • Extensive austempering in these microstructures has not been reported before. • Precipitation of cementite particles is unavoidable at longer austempering times. • TEM, FEG-SEM and XRD analysis were used for microstructural characterization.

  5. Buckling of Fiber Reinforced Composite Plates with Nanofiber Reinforced Matrices

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Murthy, Pappu L. N.

    2010-01-01

    Anisotropic composite plates were evaluated with nanofiber reinforced matrices (NFRM). The nanofiber reinforcement volumes ratio in the matrix was 0.01. The plate dimensions were 20 by 10 by 1.0 in. (508 by 254 by 25.4 mm). Seven different loading condition cases were evaluated: three for uniaxial loading, three for pairs of combined loading, and one with three combined loadings. The anisotropy arose from the unidirectional plates having been at 30 from the structural axis. The anisotropy had a full 6 by 6 rigidities matrix which were satisfied and solved by a Galerkin buckling algorithm. The buckling results showed that the NFRM plates buckled at about twice those with conventional matrix.

  6. Screening of matrices and fibers for reinforced thermoplastics intended for dental applications.

    PubMed

    Goldberg, A J; Burstone, C J; Hadjinikolaou, I; Jancar, J

    1994-02-01

    Plastics reinforced with continuous fibers (FRC) are being developed for dental applications, such as prosthodontic frameworks and orthodontic retainers. Flexure properties, stress relaxation and hydrolytic stability of FRC based on six thermoplastic matrices, three types of fibers, and three fiber volume fractions were evaluated. Samples with clinically relevant dimensions were tested. Polycarbonate was the preferred matrix material. Polycarbonate reinforced with 42 volume percent glass fibers exhibited the highest combination of flexure modulus (17.9 +/- 2.6 GPa), flexure strength (426 +/- 40 MPa), reinforcing efficiency (0.79), and resistance to stress relaxation. No statistically significant difference was observed between E and S2 glass reinforced composites under the experimental conditions used. Kevlar reinforced materials exhibited a low flexure modulus and strength. The apparent flexure moduli of all composites decreased with span length in the range of clinical interest. Generally, the prevalent mode of failure for all FRC investigated was brittle failure under flexure loading. Relatively large sample-to-sample variation in both composition and properties indicated that improved fabrication methods will be needed in future studies. The combination of good flexure properties, formability, and translucency suggests that novel appliance designs for dentistry are feasible with FRC, but further studies of its properties and particularly the effects of fiber/matrix interfacial quality are needed.

  7. Automatic tuning of the reinforcement function

    SciTech Connect

    Touzet, C.; Santos, J.M.

    1997-12-31

    The aim of this work is to present a method that helps tuning the reinforcement function parameters in a reinforcement learning approach. Since the proposal of neural based implementations for the reinforcement learning paradigm (which reduced learning time and memory requirements to realistic values) reinforcement functions have become the critical components. Using a general definition for reinforcement functions, the authors solve, in a particular case, the so called exploration versus exploitation dilemma through the careful computation of the RF parameter values. They propose an algorithm to compute, during the exploration part of the learning phase, an estimate for the parameter values. Experiments with the mobile robot Nomad 200 validate their proposals.

  8. Investigation of Selectively-Reinforced Metallic Lugs

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.; Abada, Christopher H.

    2007-01-01

    An investigation of the effects of material and geometric variables on the response of U-shaped band-reinforced metallic lugs was performed. Variables studied were reinforcement, adhesive and metallic lug mechanical properties, hole diameter, reinforcement and adhesive thickness, and the distance from the hole s center to the end of the lug. Generally, U-shaped band reinforced lugs exhibited superior performance than non-reinforced lugs, that is higher load at the conventional lug design criteria of four percent hole elongation. Depending upon the reinforcement configuration the increase in load may be negligible to 15 or 20 percent. U-shaped band reinforcement increases lug load carrying capability primarily through two mechanisms; increasing the slope of the response curve after the initial knee and restraining overall deformation of the metallic portion of the lug facilitating increased yielding of metallic material between the hole and the edge of the metallic portion of the lug.

  9. Human choice under schedules of negative reinforcement.

    PubMed

    Alessandri, Jérôme; Cançado, Carlos R X

    2015-12-01

    The generalized matching equation provides a good description of response allocation in concurrent schedules of positive reinforcement in nonhumans as well as in humans. The present experiment was conducted to further investigate the allocation of responding under concurrent schedules of negative reinforcement (i.e., timeouts from pressing a force cell) in humans. Each of three participants was exposed to different reinforcement ratios (9:1, 1:1 and 1:9) in the terminal links of a concurrent-chains schedule of negative reinforcement. The allocation of responding under this schedule was well described by the generalized matching equation, for each participant. These results replicate previous findings obtained with nonhumans and humans under concurrent schedules of positive reinforcement. In addition, they extend the results reported by Alessandri and Rivière (2013) showing that human behavior maintained by timeouts from an effortful response is sensitive to changes in relative reinforcement ratios as well as relative delays of reinforcement. PMID:26518610

  10. Human choice under schedules of negative reinforcement.

    PubMed

    Alessandri, Jérôme; Cançado, Carlos R X

    2015-12-01

    The generalized matching equation provides a good description of response allocation in concurrent schedules of positive reinforcement in nonhumans as well as in humans. The present experiment was conducted to further investigate the allocation of responding under concurrent schedules of negative reinforcement (i.e., timeouts from pressing a force cell) in humans. Each of three participants was exposed to different reinforcement ratios (9:1, 1:1 and 1:9) in the terminal links of a concurrent-chains schedule of negative reinforcement. The allocation of responding under this schedule was well described by the generalized matching equation, for each participant. These results replicate previous findings obtained with nonhumans and humans under concurrent schedules of positive reinforcement. In addition, they extend the results reported by Alessandri and Rivière (2013) showing that human behavior maintained by timeouts from an effortful response is sensitive to changes in relative reinforcement ratios as well as relative delays of reinforcement.

  11. Alumina-Reinforced Zirconia Composites

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Bansal, Narottam P.

    2003-01-01

    Alumina-reinforced zirconia composites, used as electrolyte materials for solid oxide fuel cells, were fabricated by hot pressing 10 mol percent yttria-stabilized zirconia (10-YSZ) reinforced with two different forms of alumina particulates and platelets each containing 0 to 30 mol percent alumina. Major mechanical and physical properties of both particulate and platelet composites including flexure strength, fracture toughness, slow crack growth, elastic modulus, density, Vickers microhardness, thermal conductivity, and microstructures were determined as a function of alumina content either at 25 C or at both 25 and 1000 C. Flexure strength and fracture toughness at 1000 C were maximized with 30 particulate and 30 mol percent platelet composites, respectively, while resistance to slow crack growth at 1000 C in air was greater for 30 mol percent platelet composite than for 30 mol percent particulate composites.

  12. Wax Reinforces Honeycomb During Machining

    NASA Technical Reports Server (NTRS)

    Towell, Timothy W.; Fahringer, David T.; Vasquez, Peter; Scheidegger, Alan P.

    1995-01-01

    Method of machining on conventional metal lathe devised for precise cutting of axisymmetric contours on honeycomb cores made of composite (matrix/fiber) materials. Wax filling reinforces honeycomb walls against bending and tearing while honeycomb being contoured on lathe. Innovative method of machining on lathe involves preparation in which honeycomb is placed in appropriate fixture and the fixture is then filled with molten water-soluble wax. Number of different commercial waxes have been tried.

  13. The aging nursing workforce: How to retain experienced nurses.

    PubMed

    Cohen, Jeremye D

    2006-01-01

    In the face of an anticipated nursing shortage, healthcare organizations must evaluate their culture, operations, and compensation system to ensure that these elements align with organizational efforts to retain nurses who are approaching retirement age. Management should focus on enhancing elements of job satisfaction and job embeddedness that will motivate nurses to remain both in the workforce and with their employer. Although much of this responsibility falls on the nurse manager, nurse managers are often not provided the necessary support by top management and are neither recognized nor held accountable for nurse turnover. Other retention initiatives can include altering working conditions to reduce both physical and mental stress and addressing issues of employee health and safety. As for compensation, organizations may be well-served by offering senior nursing staff flexible working hours, salary structures that reward experience, and benefit programs that hold value for an aging workforce. PMID:16916117

  14. Retaining local image information in gamut mapping algorithms.

    PubMed

    Zolliker, Peter; Simon, Klaus

    2007-03-01

    Our topic is the potential of combining global gamut mapping with spatial methods to retain the percepted local image information in gamut mapping algorithms. The main goal is to recover the original local contrast between neighboring pixels in addition to the usual optimization of preserving lightness, saturation, and global contrast. Special emphasis is placed on avoiding artifacts introduced by the gamut mapping algorithm itself. We present an unsharp masking technique based on an edge-preserving smoothing algorithm allowing to avoid halo artifacts. The good performance of the presented approach is verified by a psycho-visual experiment using newspaper printing as a representative of a small destination gamut application. Furthermore, the improved mapping properties are documented with local mapping histograms. PMID:17357727

  15. Transorbital Stab Injury with Retained Knife: A Narrow Escape

    PubMed Central

    Alharthy, Abdulrehman; Aletreby, Waleed Tharwat; Huwait, Basim; Kulshrestha, Akhilesh

    2014-01-01

    Transorbital penetrating injuries are unusual but may cause severe brain damage if cranium is entered. These kinds of injuries are dangerous as the walls of orbit are very thin, hence easily broken by the otherwise innocent objects. Because of the very critical anatomical area involved, these injuries pose a serious challenge to the physicians who first receive them as well as the treating team. These may present as trivial trauma or may be occult and are often associated with serious complications and delayed sequel. Prompt evaluation by utilizing best diagnostic modality available and timely interference to remove them are the key aspects to avoid damage to vital organs surrounding the injury and to minimize the late complications. We report a case of transorbital assault with a 13 centimeter long knife which got broken from the handle and the blade was retained. The interesting aspect is that there was no neurological deficit on presentation or after removal. PMID:25328717

  16. Hader bar and clip attachment retained mandibular complete denture

    PubMed Central

    Singh, Kunwarjeet; Gupta, Nidhi; Kapoor, Vikram; Gupta, Ridhimaa

    2013-01-01

    Bar and clip attachments significantly improve the level of satisfaction of denture-wearing patients by enhancing the retention and stability of the prosthesis. These attachments have been most commonly used for connecting the prosthesis to implants, but they can be effectively used to retain tooth-supported prosthesis as well. The primary functions of bar attachments are splinting the abutments together, even distribution of forces to the abutments and supporting areas, guiding the prosthesis into place, improving the retention, stability, support and comfort of the patient. The primary requirement for the use of bar attachments is the availability of sufficient vertical and buccolingual space for the proper placement of the bar, sleeves, teeth arrangement and sufficient thickness of acrylic denture base to minimise incidence of denture fracture in the area of bar assembly. PMID:24145505

  17. The aging nursing workforce: How to retain experienced nurses.

    PubMed

    Cohen, Jeremye D

    2006-01-01

    In the face of an anticipated nursing shortage, healthcare organizations must evaluate their culture, operations, and compensation system to ensure that these elements align with organizational efforts to retain nurses who are approaching retirement age. Management should focus on enhancing elements of job satisfaction and job embeddedness that will motivate nurses to remain both in the workforce and with their employer. Although much of this responsibility falls on the nurse manager, nurse managers are often not provided the necessary support by top management and are neither recognized nor held accountable for nurse turnover. Other retention initiatives can include altering working conditions to reduce both physical and mental stress and addressing issues of employee health and safety. As for compensation, organizations may be well-served by offering senior nursing staff flexible working hours, salary structures that reward experience, and benefit programs that hold value for an aging workforce.

  18. Diet-induced obese mice retain endogenous leptin action.

    PubMed

    Ottaway, Nickki; Mahbod, Parinaz; Rivero, Belen; Norman, Lee Ann; Gertler, Arieh; D'Alessio, David A; Perez-Tilve, Diego

    2015-06-01

    Obesity is characterized by hyperleptinemia and decreased response to exogenous leptin. This has been widely attributed to the development of leptin resistance, a state of impaired leptin signaling proposed to contribute to the development and persistence of obesity. To directly determine endogenous leptin activity in obesity, we treated lean and obese mice with a leptin receptor antagonist. The antagonist increased feeding and body weight (BW) in lean mice, but not in obese models of leptin, leptin receptor, or melanocortin-4 receptor deficiency. In contrast, the antagonist increased feeding and BW comparably in lean and diet-induced obese (DIO) mice, an increase associated with decreased hypothalamic expression of Socs3, a primary target of leptin. These findings demonstrate that hyperleptinemic DIO mice retain leptin suppression of feeding comparable to lean mice and counter the view that resistance to endogenous leptin contributes to the persistence of DIO in mice.

  19. Apparatus and Process for Controlled Nanomanufacturing Using Catalyst Retaining Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien (Inventor)

    2013-01-01

    An apparatus and method for the controlled fabrication of nanostructures using catalyst retaining structures is disclosed. The apparatus includes one or more modified force microscopes having a nanotube attached to the tip portion of the microscopes. An electric current is passed from the nanotube to a catalyst layer of a substrate, thereby causing a localized chemical reaction to occur in a resist layer adjacent the catalyst layer. The region of the resist layer where the chemical reaction occurred is etched, thereby exposing a catalyst particle or particles in the catalyst layer surrounded by a wall of unetched resist material. Subsequent chemical vapor deposition causes growth of a nanostructure to occur upward through the wall of unetched resist material having controlled characteristics of height and diameter and, for parallel systems, number density.

  20. Self-Retaining Retractor Support—New Applications

    PubMed Central

    Thompson, Richard C.

    1964-01-01

    A retractor support consisting of an inverted L-rod, fastened to the operating table with a clamp, can be applied in a variety of ways to maintain retraction more conveniently and reliably in some circumstances than a human assistant. Through universal joints and connecting rods it can be quickly adjusted to hold a Weinberg retractor, a BiBall retainer, a rectangular frame for multidirectional retraction in vascular repair, or a ribbon retractor for herniotomy, pneumonectomy and lobectomy. By freeing the assistant this device can shorten operating time and permit cumbersome procedures to be accomplished by a surgeon and one assistant with less operative trauma. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:14201242

  1. Reaching (and retaining) Broader Audiences in Citizen Science.

    NASA Astrophysics Data System (ADS)

    Cavalier, D.

    2015-12-01

    Individuals come to citizen science from different perspectives and preferences, and engage in a wide range of projects from data collection to public policy (Irwin 1995, Bonney et al. 2009a). Many participate exclusively online in crowdsourcing projects such as Galaxy Zoo, Fold-It, and Eyewire. Hundreds of thousands gather data on-the-ground for academic andcommunity research projects led by scientists at universities, government agencies/NGOs, and nonprofits. Untold others initiate their own projects in response to local environmental and health issues. All types of citizen science endeavors face challenges around data access and management, around relationships with scientists and project managers, and around making their scientific accomplishments visible as they accumulate over time. Among the most universal and ongoing challenges for all types of citizen science, however, "is attracting and retaining enough participants to make achievement of project goals possible." (Crowston and Prestopnik One known reason for this issue is the reality that individual projects and project types exist in "silos" - as self-segregated groups with particular shared interests (Dickinson et al. 2010). What efforts can be made in digital infrastructures and community building efforts to enable the unprecedented ability to support and retain diverse types of citizen science participation and data exchange between communities? How do we support participation in, and management of, multiple projects; continuity in, and sharing of, a broad and accessible citizen science community; and related social components? This presentation will provide a brief overview of the known barriers to this "utopia" and a snapshot of efforts underway to address many of these barriers.

  2. Recruiting and retaining high-quality teachers in rural areas.

    PubMed

    Monk, David H

    2007-01-01

    In examining recruitment and retention of teachers in rural areas, David Monk begins by noting the numerous possible characteristics of rural communities--small size, sparse settlement, distance from population concentrations, and an economic reliance on agricultural industries that are increasingly using seasonal and immigrant workers to minimize labor costs. Many, though not all, rural areas, he says, are seriously impoverished. Classes in rural schools are relatively small, and teachers tend to report satisfaction with their work environments and relatively few problems with discipline. But teacher turnover is often high, and hiring can be difficult. Monk observes that rural schools have a below-average share of highly trained teachers. Compensation in rural schools tends to be low, perhaps because of a lower fiscal capacity in rural areas, thus complicating efforts to attract and retain teachers. Several student characteristics, including relatively large shares of students with special needs and with limited English skills and lower shares of students attending college, can also make it difficult to recruit and retain high-quality teachers. Other challenges include meeting the needs of highly mobile children of low-income migrant farm workers. With respect to public policy, Monk asserts a need to focus on a subcategory of what might be called hard-to-staff rural schools rather than to develop a blanket set of policies for all rural schools. In particular, he recommends a focus on such indicators as low teacher qualifications, teaching in fields far removed from the area of training, difficulty in hiring, high turnover, a lack of diversity among teachers in the school, and the presence of migrant farm workers' children. Successful efforts to stimulate economic growth in these areas would be highly beneficial. He also calls attention to the potential for modern telecommunication and computing technologies to offset some of the drawbacks associated with teaching

  3. Quantification of brain perfusion with tracers retained by the brain

    SciTech Connect

    Pupi, A.; Bacciottini, L.; De Cristofaro, M.T.R.; Formiconi, A.R.; Castagnoli, A.

    1991-12-31

    Almost a decade ago, tracers, labelled with {sup 123}I and {sup 99m}Tc, that are retained by the brain, started to be used for studies of regional brain perfusion (regional cerebral blood flow, rCBF). To date, these tracers have been used for brain perfusion imaging with SPECT in brain disorders as well as for physiological activation protocols. Only seldom, however, have they been used in protocols that quantitatively measure rCBF. Nevertheless, comparative studies with perfusion reference tracers have repeatedly demonstrated that the brain uptake of these brain-retained tracers is correlated to perfusion, the major determinant of the distribution of these tracers in the brain. The brain kinetics of {sup 99m}Tc HMPAO, which is the tracer most commonly used, was described with a two-compartment tissue model. The theoretical approach, which is, in itself, sufficient for modeling quantitative measurements with {sup 99m}Tc HMPAO, initially suggested the possibility of empirically narrowing the distance between the brain`s regional uptake of the tracer and rCBF with a linearization algorithm which uses the cerebellum as the reference region. The value of this empirical method is hampered by the fact that the cerebellum can be involved in cerebrovascular disease (i.e. cerebellar diaschisis) as well as in several other brain disorders (e.g. anxiety, and dementia of the Alzheimer type). It also was proposed that different reference regions (occipital, whole slice, or whole brain) should be selected in relation to the brain disorder under study. However, this approach does not solve the main problem because it does not equip us with a reliable tool to evaluate rCBF with a high predictive value, and, at the same time, to reduce intersubject variability. The solution would be to measure a quantitative parameter which directly reflects rCBF, such as the unidirectional influx constant of the freely diffusible flow-limited tracers. 45 refs., 3 figs., 1 tab.

  4. 26 CFR 1.636-2 - Production payments retained in leasing transactions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Production payments retained in leasing... payments retained in leasing transactions. (a) Treatment by lessee. In the case of a production payment (as defined in paragraph (a) of § 1.636-3) which is retained by the lessor in a leasing transaction...

  5. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  6. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  7. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  8. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  9. 7 CFR 97.17 - Papers of completed application to be retained.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Papers of completed application to be retained. 97.17... LABORATORY TESTING PROGRAMS PLANT VARIETY AND PROTECTION The Application § 97.17 Papers of completed application to be retained. The papers submitted with a completed application shall be retained by the...

  10. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  11. 41 CFR 102-37.270 - May a SASP retain surplus property for its own use?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false May a SASP retain surplus property for its own use? 102-37.270 Section 102-37.270 Public Contracts and Property Management... Property § 102-37.270 May a SASP retain surplus property for its own use? Yes, you can retain...

  12. 7 CFR 97.17 - Papers of completed application to be retained.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Papers of completed application to be retained. 97.17... LABORATORY TESTING PROGRAMS PLANT VARIETY AND PROTECTION The Application § 97.17 Papers of completed application to be retained. The papers submitted with a completed application shall be retained by the...

  13. Antimony release from contaminated mine soils and its migration in four typical soils using lysimeter experiments.

    PubMed

    Shangguan, Yu-Xian; Zhao, Long; Qin, Yusheng; Hou, Hong; Zhang, Naiming

    2016-11-01

    Antimony (Sb) can pose great risks to the environment in mining and smelting areas. The migration of Sb in contaminated mine soil was studied using lysimeter experiments. The exchangeable concentration of soil Sb decreased with artificial leaching. The concentrations of Sb retained in the subsoil layers (5-25cm deep) were the highest for Isohumosol and Ferrosol and the lowest for Sandy soil. The Sb concentrations in soil solutions decreased with soil depth, and were adequately simulated using a logarithmic function. The Sb migration pattern in Sandy soil was markedly different from the patterns in the other soils which suggested that Sb may be transported in soil colloids. Environmental factors such as water content, soil temperature, and oxidation-reduction potential of the soil had different effects on Sb migration in Sandy soil and Primosol. The high Fe and Mn contents in Ferrosol and Isohumosol significantly decreased the mobility of Sb in these soils. The Na and Sb concentrations in soils used in the experiments positively correlated with each other (P<0.01). The Sb concentrations in soil solutions, the Sb chemical fraction patterns, and the Sb/Na ratios decreased in the order Sandy soil>Primosol>Isohumosol>Ferrosol, and we concluded that the Sb mobility in the soils also decreased in that order. PMID:27395817

  14. Antimony release from contaminated mine soils and its migration in four typical soils using lysimeter experiments.

    PubMed

    Shangguan, Yu-Xian; Zhao, Long; Qin, Yusheng; Hou, Hong; Zhang, Naiming

    2016-11-01

    Antimony (Sb) can pose great risks to the environment in mining and smelting areas. The migration of Sb in contaminated mine soil was studied using lysimeter experiments. The exchangeable concentration of soil Sb decreased with artificial leaching. The concentrations of Sb retained in the subsoil layers (5-25cm deep) were the highest for Isohumosol and Ferrosol and the lowest for Sandy soil. The Sb concentrations in soil solutions decreased with soil depth, and were adequately simulated using a logarithmic function. The Sb migration pattern in Sandy soil was markedly different from the patterns in the other soils which suggested that Sb may be transported in soil colloids. Environmental factors such as water content, soil temperature, and oxidation-reduction potential of the soil had different effects on Sb migration in Sandy soil and Primosol. The high Fe and Mn contents in Ferrosol and Isohumosol significantly decreased the mobility of Sb in these soils. The Na and Sb concentrations in soils used in the experiments positively correlated with each other (P<0.01). The Sb concentrations in soil solutions, the Sb chemical fraction patterns, and the Sb/Na ratios decreased in the order Sandy soil>Primosol>Isohumosol>Ferrosol, and we concluded that the Sb mobility in the soils also decreased in that order.

  15. Pavlovian conditioning and cumulative reinforcement rate.

    PubMed

    Harris, Justin A; Patterson, Angela E; Gharaei, Saba

    2015-04-01

    In 5 experiments using delay conditioning of magazine approach with rats, reinforcement rate was varied either by manipulating the mean interval between onset of the conditioned stimulus (CS) and unconditioned stimulus (US) or by manipulating the proportion of CS presentations that ended with the US (trial-based reinforcement rate). Both manipulations influenced the acquisition of responding. In each experiment, a specific comparison was made between 2 CSs that differed in their mean CS-US interval and in their trial-based reinforcement rate, such that the cumulative reinforcement rate-the cumulative duration of the CS between reinforcements-was the same for the 2 CSs. For example, a CS reinforced on 100% of trials with a mean CS-US interval of 60 s was compared with a CS reinforced on 33% of trials and a mean duration of 20 s. Across the 5 experiments, conditioning was virtually identical for the 2 CSs with matched cumulative reinforcement rate. This was true as long as the timing of the US was unpredictable and, thus, response rates were uniform across the length of the CS. We conclude that the effects of CS-US interval and of trial-based reinforcement rate are reducible entirely to their common effect on cumulative reinforcement rate. We discuss the implications of this for rate-based, trial-based, and real-time associative models of conditioning.

  16. Comparative Evaluation of Microleakage of Lingual Retainer Wires Bonded with Three Different Lingual Retainer Composites: An In Vitro Study

    PubMed Central

    Vaz, Anna; Patil, Pravinkumar G.

    2014-01-01

    Objective: To evaluate microleakage when two types of retainer wires were bonded with two light cured and a self cured lingual retainer composites. Materials and Methods: Total 120 freshly extracted human mandibular incisor teeth were collected and separated into six subgroups of 20 teeth each. Two different wires, a 0.036 inch hard round stainless steel (HRSS) wire sandblasted at the ends and 0.0175 inch multistranded wire bonded onto the lingual surfaces of the incisors with three different types of composite resins of 3M company; Concise Orthodontic (self-cure), Transbond XT (light-cure) and Transbond LR (light-cure). Specimens were further sealed with a nail varnish, stained with 0.5% basic fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-composite and wire-composite interfaces. Statistical analysis was performed by Kruskal-Wallis and Mann-Whitney U-tests. Results: For HRSS wire, at the enamel-composite interface, the microleakage was least with Transbond LR followed by Concise Orthodontic and greatest for Transbond XT (p<0.05). At the wire composite interface too, the microleakage was in order of Transbond LR

  17. Carbon black retention in saturated natural soils: Effects of flow conditions, soil surface roughness and soil organic matter.

    PubMed

    Lohwacharin, J; Takizawa, S; Punyapalakul, P

    2015-10-01

    We evaluated factors affecting the transport, retention, and re-entrainment of carbon black nanoparticles (nCBs) in two saturated natural soils under different flow conditions and input concentrations using the two-site transport model and Kelvin probe force microscopy (KPFM). Soil organic matter (SOM) was found to create unfavorable conditions for the retention. Despite an increased flow velocity, the relative stability of the estimated maximum retention capacity in soils may suggest that flow-induced shear stress forces were insufficient to detach nCB. The KPFM observation revealed that nCBs were retained at the grain boundary and on surface roughness, which brought about substantial discrepancy between theoretically-derived attachment efficiency factors and the ones obtained by the experiments using the two-site transport model. Thus, decreasing ionic strength and increasing solution pH caused re-entrainment of only a small fraction of retained nCB in the soil columns.

  18. Understanding plant root system influences on soil strength and stability

    NASA Astrophysics Data System (ADS)

    Bengough, A. Glyn; Brown, Jennifer L.; Loades, Kenneth W.; Knappett, Jonathan A.; Meijer, Gertjan; Nicoll, Bruce

    2016-04-01

    Keywords: root growth, soil reinforcement, tensile strength Plant roots modify and reinforce the soil matrix, stabilising it against erosion and shallow landslides. Roots mechanically bind the soil particles together and modify the soil hydrology via water uptake, creation of biopores, and modification of the soil water-release characteristic. Key to understanding the mechanical reinforcement of soil by roots is the relation between root strength and root diameter measured for roots in any given soil horizon. Thin roots have frequently been measured to have a greater tensile strength than thick roots, but their strength is also often much more variable. We consider the factors influencing this strength-diameter relationship, considering relations between root tensile strength and root dry density, root water content, root age, and root turnover in several woody and non-woody species. The role of possible experimental artefacts and measurement techniques will be considered. Tensile strength increased generally with root age and decreased with thermal time after excision as a result of root decomposition. Single factors alone do not appear to explain the strength-diameter relationship, and both strength/stiffness and dry density may vary between different layers of tissue within a single root. Results will be discussed to consider how we can achieve a more comprehensive understanding of the variation in root biomechanical properties, and its consequences for soil reinforcement. Acknowledgements: The James Hutton Institute receives funding from the Scottish Government. AGB and JAK acknowledge part funding from EPSRC (EP/M020355/1).

  19. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    PubMed

    Edwards, Felicity A; Edwards, David P; Sloan, Sean; Hamer, Keith C

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture.

  20. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    PubMed

    Edwards, Felicity A; Edwards, David P; Sloan, Sean; Hamer, Keith C

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture. PMID:24638038

  1. Sustainable Management in Crop Monocultures: The Impact of Retaining Forest on Oil Palm Yield

    PubMed Central

    Edwards, Felicity A.; Edwards, David P.; Sloan, Sean; Hamer, Keith C.

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture. PMID:24638038

  2. Reinforcement of vocalizations through contingent vocal imitation.

    PubMed

    Pelaez, Martha; Virues-Ortega, Javier; Gewirtz, Jacob L

    2011-01-01

    Maternal vocal imitation of infant vocalizations is highly prevalent during face-to-face interactions of infants and their caregivers. Although maternal vocal imitation has been associated with later verbal development, its potentially reinforcing effect on infant vocalizations has not been explored experimentally. This study examined the reinforcing effect of maternal vocal imitation of infant vocalizations using a reversal probe BAB design. Eleven 3- to 8-month-old infants at high risk for developmental delays experienced contingent maternal vocal imitation during reinforcement conditions. Differential reinforcement of other behavior served as the control condition. The behavior of 10 infants showed evidence of a reinforcement effect. Results indicated that vocal imitations can serve to reinforce early infant vocalizations. PMID:21541136

  3. A progressive-duration schedule of reinforcement.

    PubMed

    Gulotta, Kara B; Byrne, Tom

    2015-12-01

    We describe a schedule of reinforcement involving systematic, within-session increases in response-duration requirements. Rats received access to appetitive reinforcers for depressing and holding down a response lever. Duration requirements increased after each reinforcer delivery. Sessions ended when reinforcement criteria were unmet for a period of ten minutes. Breaking points, defined as the terminal duration requirement in effect prior to the end of the session, stabilized when environmental conditions were held constant. Breaking points were sensitive to manipulations of both food deprivation and reinforcer quality. Analogous to progressive-ratio schedules, progressive-duration schedules may provide an assay for measuring the amount of behavior an organism will emit for a given reinforcer under current motivational conditions.

  4. Reinforcement of vocalizations through contingent vocal imitation.

    PubMed

    Pelaez, Martha; Virues-Ortega, Javier; Gewirtz, Jacob L

    2011-01-01

    Maternal vocal imitation of infant vocalizations is highly prevalent during face-to-face interactions of infants and their caregivers. Although maternal vocal imitation has been associated with later verbal development, its potentially reinforcing effect on infant vocalizations has not been explored experimentally. This study examined the reinforcing effect of maternal vocal imitation of infant vocalizations using a reversal probe BAB design. Eleven 3- to 8-month-old infants at high risk for developmental delays experienced contingent maternal vocal imitation during reinforcement conditions. Differential reinforcement of other behavior served as the control condition. The behavior of 10 infants showed evidence of a reinforcement effect. Results indicated that vocal imitations can serve to reinforce early infant vocalizations.

  5. Failure to produce response variability with reinforcement

    PubMed Central

    Schwartz, Barry

    1982-01-01

    Two experiments attempted to train pigeons to produce variable response sequences. In the first, naive pigeons were exposed to a procedure requiring four pecks on each of two keys in any order, with a reinforcer delivered only if a given sequence was different from the preceding one. In the second experiment, the same pigeons were exposed to this procedure after having been trained successfully to alternate between two specific response sequences. In neither case did any pigeon produce more than a few different sequences or obtain more than 50% of the possible reinforcers. Stereotyped sequences developed even though stereotypy was not reinforced. It is suggested that reinforcers have both hedonic and informative properties and that the hedonic properties are responsible for sterotyped repetition of reinforced responses, even when stereotypy is negatively related to reinforcer delivery. PMID:16812263

  6. Behavior systems and reinforcement: an integrative approach.

    PubMed Central

    Timberlake, W

    1993-01-01

    Most traditional conceptions of reinforcement are based on a simple causal model in which responding is strengthened by the presentation of a reinforcer. I argue that reinforcement is better viewed as the outcome of constraint of a functioning causal system comprised of multiple interrelated causal sequences, complex linkages between causes and effects, and a set of initial conditions. Using a simplified system conception of the reinforcement situation, I review the similarities and drawbacks of traditional reinforcement models and analyze the recent contributions of cognitive, regulatory, and ecological approaches. Finally, I show how the concept of behavior systems can begin to incorporate both traditional and recent conceptions of reinforcement in an integrative approach. PMID:8354963

  7. Graphite fiber reinforced thermoplastic resins

    NASA Technical Reports Server (NTRS)

    Novak, R. C.

    1975-01-01

    Mechanical properties of neat resin samples and graphite fiber reinforced samples of thermoplastic resins were characterized with particular emphasis directed to the effects of environmental exposure (humidity, temperature and ultraviolet radiation). Tensile, flexural, interlaminar shear, creep and impact strengths were measured for polysulfone, polyarylsulfone and a state-of-the-art epoxy resin samples. In general, the thermoplastic resins exhibited environmental degradation resistance equal to or superior to the reference epoxy resin. Demonstration of the utility and quality of a graphite/thermoplastic resin system was accomplished by successfully thermoforming a simulated compressor blade and a fan exit guide vane.

  8. Bacterial RNA polymerase can retain σ70 throughout transcription

    PubMed Central

    Harden, Timothy T.; Wells, Christopher D.; Friedman, Larry J.; Landick, Robert; Hochschild, Ann; Kondev, Jane

    2016-01-01

    Production of a messenger RNA proceeds through sequential stages of transcription initiation and transcript elongation and termination. During each of these stages, RNA polymerase (RNAP) function is regulated by RNAP-associated protein factors. In bacteria, RNAP-associated σ factors are strictly required for promoter recognition and have historically been regarded as dedicated initiation factors. However, the primary σ factor in Escherichia coli, σ70, can remain associated with RNAP during the transition from initiation to elongation, influencing events that occur after initiation. Quantitative studies on the extent of σ70 retention have been limited to complexes halted during early elongation. Here, we used multiwavelength single-molecule fluorescence-colocalization microscopy to observe the σ70–RNAP complex during initiation from the λ PR′ promoter and throughout the elongation of a long (>2,000-nt) transcript. Our results provide direct measurements of the fraction of actively transcribing complexes with bound σ70 and the kinetics of σ70 release from actively transcribing complexes. σ70 release from mature elongation complexes was slow (0.0038 s−1); a substantial subpopulation of elongation complexes retained σ70 throughout transcript elongation, and this fraction depended on the sequence of the initially transcribed region. We also show that elongation complexes containing σ70 manifest enhanced recognition of a promoter-like pause element positioned hundreds of nucleotides downstream of the promoter. Together, the results provide a quantitative framework for understanding the postinitiation roles of σ70 during transcription. PMID:26733675

  9. The Role of Organizational Culture in Retaining Nursing Workforce

    PubMed Central

    Banaszak-Holl, Jane; Castle, Nicholas G.; Lin, Michael K.; Shrivastwa, Nijika; Spreitzer, Gretchen

    2015-01-01

    Purpose of the Study: We examined how organizational culture in nursing homes affects staff turnover, because culture is a first step to creating satisfactory work environments. Design and Methods: Nursing home administrators were asked in 2009 to report on facility culture and staff turnover. We received responses from 419 of 1,056 administrators contacted. Respondents reported the strength of cultural values using scales from a Competing Values Framework and percent of staff leaving annually for Registered Nurse (RN), Licensed Practice Nurse (LPN), and nursing aide (NA) staff. We estimated negative binomial models predicting turnover.  Results: Turnover rates are lower than found in past but remain significantly higher among NAs than among RNs or LPNs. Facilities with stronger market values had increased turnover among RNs and LPNs, and among NAs when turnover was adjusted for facilities with few staff. Facilities emphasizing hierarchical internal processes had lower RN turnover. Group and developmental values focusing on staff and innovation only lowered LPN turnover. Finally, effects on NA turnover become insignificant when turnover was adjusted if voluntary turnover was reported. Implications: Organizational culture had differential effects on the turnover of RN, LPN, and NA staff that should be addressed in developing culture-change strategies. More flexible organizational culture values were important for LPN staff only, whereas unexpectedly, greater emphasis on rigid internal rules helped facilities retain RNs. Facilities with a stronger focus on customer needs had higher turnover among all staff. PMID:24218146

  10. Magnet retained lip prosthesis in a geriatric patient.

    PubMed

    Rao, Srinivasa B; Gurram, Sunil Kumar; Mishra, Sunil Kumar; Chowdhary, Ramesh

    2015-01-01

    Surgical resection of lips is a relatively rare procedure. A defective lip may cause the patient to feel socially vulnerable as well as functionally handicapped and the defect will influence the patient's self-esteem and body image. Patients with labial defects also experience speech problems along with drying and crusting of the tissues in the area of defect. The lip and cheek provide a valve mechanism for speech. Rehabilitation of patients with this type of surgery creates numerous challenges for both the surgical and the maxillofacial prosthetic teams. The goals of prosthetic treatment include regaining favorable speech and restoration of esthetics. This case report presents a 65-year-old woman who was referred for restoration of her lost lip. This case paper describes a quick and simple method of positioning magnets with lip prosthesis attached to maxillary denture and thus esthetics and speech of the patient is restored. Use of retention magnets simplify the clinical and laboratory phase retains the denture and makes it stable and comfortable for the patient. The advent of magnets has enhanced the dental practitioner's capabilities with a remarkably improved potential for increasing prosthesis stability and preserving tissue. PMID:26929510

  11. Magnet retained lip prosthesis in a geriatric patient

    PubMed Central

    Rao, Srinivasa B; Gurram, Sunil Kumar; Mishra, Sunil Kumar; Chowdhary, Ramesh

    2015-01-01

    Surgical resection of lips is a relatively rare procedure. A defective lip may cause the patient to feel socially vulnerable as well as functionally handicapped and the defect will influence the patient's self-esteem and body image. Patients with labial defects also experience speech problems along with drying and crusting of the tissues in the area of defect. The lip and cheek provide a valve mechanism for speech. Rehabilitation of patients with this type of surgery creates numerous challenges for both the surgical and the maxillofacial prosthetic teams. The goals of prosthetic treatment include regaining favorable speech and restoration of esthetics. This case report presents a 65-year-old woman who was referred for restoration of her lost lip. This case paper describes a quick and simple method of positioning magnets with lip prosthesis attached to maxillary denture and thus esthetics and speech of the patient is restored. Use of retention magnets simplify the clinical and laboratory phase retains the denture and makes it stable and comfortable for the patient. The advent of magnets has enhanced the dental practitioner's capabilities with a remarkably improved potential for increasing prosthesis stability and preserving tissue. PMID:26929510

  12. Cruciate retaining and cruciate substituting ultra-congruent insert

    PubMed Central

    Deledda, Davide; Rosso, Federica; Ratto, Nicola; Bruzzone, Matteo; Bonasia, Davide Edoardo; Rossi, Roberto

    2016-01-01

    The posterior cruciate ligament (PCL) conservation and the polyethylene insert constraint in total knee arthroplasty (TKA) are still debated. The PCL is one of the primary stabilizers of the joint, but cruciate retaining (CR) implants have the disadvantage of a difficult balancing of the PCL. Postero-stabilized (PS) implants were introduced to reduce this problem. However, also the PS implants have some disadvantages, due to the cam-mechanism, such as high risk of cam-mechanism polyethylene wear. To minimize the polyethylene wear of the cam-mechanism and the bone sacrifice due to the intercondylar box, different types of inserts were developed, trying to increase the implant conformity and to reduce stresses on the bone-implant interface. In this scenario ultra-congruent (UC) inserts were developed. Those inserts are characterized by a high anterior wall and a deep-dished plate. This conformation should guarantee a good stability without the posterior cam. Few studies on both kinematic and clinical outcomes of UC inserts are available. Clinical and radiological outcomes, as well as kinematic data are similar between UC mobile bearing (MB) and standard PS MB inserts at short to mid-term follow-up. In this manuscript biomechanics and clinical outcomes of UC inserts will be described, and they will be compared to standard PS or CR inserts. PMID:26855938

  13. Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments

    PubMed Central

    Kumar, Vinod; Takkar, Brijesh

    2016-01-01

    Purpose: To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments. Methods: In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up for a minimum of six months to evaluate the visual outcomes and complications. Results: The preoperative best-corrected visual acuity (BCVA) ranged from light perception to 0.3. No complications such as thermal burns of the scleral wound, retinal damage due to flying lens fragments, or difficult lens aspiration occurred during intravitreal phacoemulsification. Mean post-operative BCVA at the final follow-up was 0.5. Two eyes developed cystoid macular edema, which was managed medically. No retinal detachment was noted. Conclusion: Intravitreal phacoemulsification using torsional hand piece is a safe and effective alternative to conventional longitudinal phacofragmentation. PMID:27621783

  14. Automated identification of retained surgical items in radiological images

    NASA Astrophysics Data System (ADS)

    Agam, Gady; Gan, Lin; Moric, Mario; Gluncic, Vicko

    2015-03-01

    Retained surgical items (RSIs) in patients is a major operating room (OR) patient safety concern. An RSI is any surgical tool, sponge, needle or other item inadvertently left in a patients body during the course of surgery. If left undetected, RSIs may lead to serious negative health consequences such as sepsis, internal bleeding, and even death. To help physicians efficiently and effectively detect RSIs, we are developing computer-aided detection (CADe) software for X-ray (XR) image analysis, utilizing large amounts of currently available image data to produce a clinically effective RSI detection system. Physician analysis of XRs for the purpose of RSI detection is a relatively lengthy process that may take up to 45 minutes to complete. It is also error prone due to the relatively low acuity of the human eye for RSIs in XR images. The system we are developing is based on computer vision and machine learning algorithms. We address the problem of low incidence by proposing synthesis algorithms. The CADe software we are developing may be integrated into a picture archiving and communication system (PACS), be implemented as a stand-alone software application, or be integrated into portable XR machine software through application programming interfaces. Preliminary experimental results on actual XR images demonstrate the effectiveness of the proposed approach.

  15. Recruiting and Retaining Arab Muslim Mothers and Children for Research

    PubMed Central

    Aroian, Karen J.; Katz, Anne; Kulwicki, Anahid

    2006-01-01

    Purpose To describe successful and not-so-successful strategies for recruiting and retaining Arab Muslim immigrant women and their adolescent children for research. Design and Methods A longitudinal study of mother-child adjustment of Arab immigrants to the US is used for illustration. A panel of experts was assembled and provided culturally specific advice about gatekeepers, advertising, data collectors, data collection, and how to track and encourage participation at subsequent time points in the study. Findings Most of the strategies recommended by the panel were overwhelmingly positive, including advice about data collectors, how to collect data, financial incentives, avoiding offending families, and personal contacts. Hiring data collectors who were able to establish personal and culturally appropriate relationships with study participants was the single most successful recruitment and retention strategy. Advice from cultural experts about which gatekeepers to engage and how to advertise for study participants was not productive. Conclusions Researchers should not only assemble a panel of cultural experts to provide advice about group specific strategies to build trust and maintain cultural sensitivity, but also to budget generously for time for data collectors to build and maintain rapport with study populations who, like Arab immigrant women, highly value personal relationships. PMID:17044343

  16. Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments

    PubMed Central

    Kumar, Vinod; Takkar, Brijesh

    2016-01-01

    Purpose: To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments. Methods: In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up for a minimum of six months to evaluate the visual outcomes and complications. Results: The preoperative best-corrected visual acuity (BCVA) ranged from light perception to 0.3. No complications such as thermal burns of the scleral wound, retinal damage due to flying lens fragments, or difficult lens aspiration occurred during intravitreal phacoemulsification. Mean post-operative BCVA at the final follow-up was 0.5. Two eyes developed cystoid macular edema, which was managed medically. No retinal detachment was noted. Conclusion: Intravitreal phacoemulsification using torsional hand piece is a safe and effective alternative to conventional longitudinal phacofragmentation.

  17. Leading a multigenerational workforce: strategies for attracting and retaining millennials.

    PubMed

    Cahill, Terrence F; Sedrak, Mona

    2012-01-01

    Over the past several years, leaders in healthcare have noticed an increase in generational tension among employees, most often focused on the attitudes and behaviors of the arriving millennials (generation Y). While these employee relations issues were a nuisance, they rarely rose to the level of a priority demanding leadership intervention. Some leaders, in fact, hoped that the issues would resolve themselves as these young employees settled in and learned that they had to demonstrate new behaviors to be successful in the workplace. Most organizations adopted this wait-and-see attitude. Not so today. As the boomer generation has begun its exodus from the workplace, organizations are increasingly looking at the millennials as not a problem but a solution to the workplace manpower transition that is under way. Our problem is that we don't yet know how best to lead such a diverse, multigenerational workforce. This article examines the generational topic and provides advice concerning a variety of changes that leaders may implement to advance their organization's ability to attract and to retain the millennials. PMID:23050333

  18. Improving wheat to remove coeliac epitopes but retain functionality

    PubMed Central

    Shewry, Peter R.; Tatham, Arthur S.

    2016-01-01

    Coeliac disease is an intolerance triggered by the ingestion of wheat gluten proteins. It is of increasing concern to consumers and health professionals as its incidence appears to be increasing. The amino acid sequences in gluten proteins that are responsible for triggering responses in sensitive individuals have been identified showing that they vary in distribution among and between different groups of gluten proteins. Conventional breeding may therefore be used to select for gluten protein fractions with lower contents of coeliac epitopes. Molecular breeding approaches can also be used to specifically down-regulate coeliac-toxic proteins or mutate coeliac epitopes within individual proteins. A combination of these approaches may therefore be used to develop a “coeliac-safe” wheat. However, this remains a formidable challenge due to the complex multigenic control of gluten protein composition. Furthermore, any modified wheats must retain acceptable properties for making bread and other processed foods. Not surprisingly, such coeliac-safe wheats have not yet been developed despite over a decade of research. PMID:26937068

  19. Retained surgical sponges: what the practicing clinician should know.

    PubMed

    Sakorafas, George H; Sampanis, Dimitrios; Lappas, Christos; Papantoni, Eva; Christodoulou, Spyros; Mastoraki, Aikaterini; Safioleas, Michael

    2010-11-01

    Retained surgical sponges (RSS) are an avoidable complication following surgical operations. RSS can elicit either an early exudative-type reaction or a late aseptic fibrous tissue reaction. They may remain asymptomatic for long time; when present, symptomatology varies substantially and includes septic complications (abscess formation, peritonitis) or fibrous reaction resulting in adhesion formation or fistulation into adjacent hollow organs or externally. Plain radiograph may be useful for the diagnosis; however, computed tomography is the method of choice to establish correct diagnosis preoperatively. Removal of RSS is always indicated to prevent further complications. This is usually accomplished by open surgery; rarely, endoscopic or laparoscopic removal may be successful. Prevention is of key importance to avoid not only morbidity and even mortality but also medicolegal consequences. Preventive measures include careful counting, use of sponges marked with a radiopaque marker, avoidance of use of small sponges during abdominal procedures, careful examination of the abdomen by the operating surgeon before closure, radiograph in the operating theater (either routinely or selectively), and recently, usage of barcode and radiofrequency identification technology. PMID:20652587

  20. Preference for unreliable reinforcement in children with mental retardation: the role of conditioned reinforcement.

    PubMed

    Lalli, J S; Mauro, B C; Mace, F C

    2000-01-01

    We examined the effects of conditioned reinforcement on children's choice between reliable (100%) and unreliable (50%) reinforcement under various stimulus conditions in a concurrent-chains procedure. The study was conducted across three experiments. Experiments 1 and 2 were conducted under conditions similar to basic laboratory work and consisted of participants selecting from one of two black boxes (placed on a table) that were correlated with different reinforcement schedules. In Experiment 3, we assessed a participant's preference for unreliable reinforcement during conditions in which the target responses were aggression and mands. Results of the three experiments showed that the participants preferred unreliable reinforcement under certain conditions. Findings are discussed regarding the role of specific stimuli (i.e., items correlated with a reinforcement schedule, adult reactions) as conditioned reinforcers and how they may influence children's preference for a response (e.g., aggression, self-injury) that produces reinforcement on a leaner schedule than a socially desirable response (e.g., mands).