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Sample records for behavior retention des

  1. SHEARING AND WATER RETENTION BEHAVIOR OF UNSATURATED LOAM WITH MODELING

    NASA Astrophysics Data System (ADS)

    Kiyohara, Yukoh; Kazama, Motoki

    Unsaturated triaxial tests were carried out to study deformation behavior, effective stress path and water retention property of consolidated loam during consolidation and shearing processes. Initial matric suction was set as 0, 50, and 90 kPa, and confining pressures (net normal stresses) were set as 100 kPa. Then shearing processes were done under undrained and drained conditions. We clarified the relation between void ratio and Van Genuchten model parameter by using water retention curve. To predict the unsaturated shearing behavior, a modified Cam Clay model considering void ratio dependent Van Genuchten parameter was proposed. Those numerical test results were agreed well with laboratory tests results.

  2. [Systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography].

    PubMed

    Fu, Qing; Wang, Jun; Liang, Tu; Xu, Xiaoyong; Jin, Yu

    2013-11-01

    A systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography (HILIC) was performed. The influences of mobile phase, stationary phase and buffer salt on the retention of carbohydrates were investigated. According to the results, the retention time of carbohydrates decreased as the proportion of acetonitrile in mobile phase decreased. Increased time of carbohydrates was observed as the concentration of buffer salt in mobile phase increased. The retention behavior of carbohydrates was also affected by organic solvent and HILIC stationary phase. Furthermore, an appropriate retention equation was used in HILIC mode. The retention equation lnk = a + blnC(B) + cC(B) could quantitatively describe the retention factors of carbohydrates of plant origin with good accuracy: the relative error of the predicted time to actual time was less than 0.3%. The evaluation results could provide guidance for carbohydrates to optimize the experimental conditions in HILIC method development especially for carbohydrate separation

  3. Men's Benefit-Provisioning Mate Retention Behavior Mediates the Relationship Between Their Agreeableness and Their Oral Sex Behaviors.

    PubMed

    Pham, Michael N; Shackelford, Todd K; Holden, Christopher J; Zeigler-Hill, Virgil; Sela, Yael; Jeffery, Austin John

    2015-08-01

    Men perform oral sex on their romantic partner as part of a broader benefit-provisioning mate retention strategy and men higher in Agreeableness are especially likely to provision their partner with benefits. The current research explored whether men's benefit-provisioning mate retention behavior mediated the relationship between their Agreeableness and their oral sex behaviors in their long-term romantic relationship. Men (n = 346) in a committed, sexual, heterosexual relationship completed the Mate Retention Inventory-a 104-item instrument that assesses the frequency with which they performed various mate retention behaviors during the past month, a 40-item personality inventory, and reported on a questionnaire their interest in and the time they spent performing oral sex on their romantic partner during their most recent sexual encounter with her. The results indicated that men higher in Agreeableness reported greater interest in and spent more time performing oral sex on their partner, and that their benefit-provisioning mate retention behaviors partially mediated these relationships. The current research is the first to investigate the relationship between personality dimensions and oral sex behaviors and adds to a growing body of research documenting that mate retention strategies influence sexual behavior.

  4. A Study to Model Human Behavior in Discrete Event Simulation (DES) using Simkit

    DTIC Science & Technology

    2007-12-01

    example, can be autonomous decision- making agents, user controlled decision inputs, or environmental conditions affecting the simulated world. Time...perception of environmental information, performance of an action, making of a commitment and even satisfaction of claims. Objects that are...reducing latency. Integrating ABS into DES [10] • Provides an effective tool to implement human-like interaction and behavior into DES, especially

  5. Retention behavior in tungsten and molybdenum exposed to high fluences of deuterium ions in TPE

    SciTech Connect

    J.P. Sharpe; R.D. Kolasinski; M. Shimada; P. Calderoni; R.A. Causey

    2009-06-01

    The Tritium Plasma Experiment (TPE) has been used to investigate deuterium fuel retention behavior in tungsten and molybdenum– materials utilized for plasma-facing surfaces in some existing tokamak plasma devices and under consideration for future devices. Although several studies have been performed over the past several years on these metals, many issues remain unresolved, including for example blister formation mechanisms and correlation to surface conditions. In this study we expose several metal samples to deuterium ion fluences up to 1026 ions/m2 and measure retention behavior with thermal desportion spectroscopy. Fractional retention of up to 2.0×10-5 is found for W at 600 K, and Mo similarly retains deuterium at a fraction of 1.5×10-5 at 600 K. Blistering was found for W samples exposed at temperatures above 453 K, whereas blistering was not observed for Mo samples at any experiment temperature.

  6. Multiple Family Groups for Child Behavior Difficulties: Retention Among Child Welfare-Involved Caregivers

    ERIC Educational Resources Information Center

    Gopalan, Geetha; Fuss, Ashley; Wisdom, Jennifer P.

    2015-01-01

    Purpose: The Multiple Family Group (MFG) service delivery model to reduce childhood disruptive behavior disorders has shown promise in engaging child welfare-involved families. This qualitative study examines caregivers' perceptions of factors that influence retention in MFGs among child welfare-involved families. Methods: Twenty-five…

  7. Multiple Family Groups for Child Behavior Difficulties Retention Among Child Welfare-Involved Caregivers.

    PubMed

    Gopalan, Geetha; Fuss, Ashley; Wisdom, Jennifer P

    2015-09-01

    Among children who remain at home with their permanent caregivers following a child welfare investigation, few who manifest emotional and behavioral difficulties actually engage in mental health treatment. The Multiple Family Group service delivery model to reduce childhood disruptive behavior disorders (MFG) has shown promise in engaging child welfare-involved families. This qualitative study examines caregiver perceptions of factors that influence retention in MFGs among child welfare-involved families.

  8. Preparation and swelling behavior of chitosan-based superporous hydrogels for gastric retention application.

    PubMed

    Park, Hyojin; Park, Kinam; Kim, Dukjoon

    2006-01-01

    Chitosan and glycol chitosan hydrogels were prepared, and their swelling behaviors in acidic solution were studied to investigate their application for gastric retention device. The optimum preparation condition of superporous hydrogels was obtained from the gelation and blowing kinetics measured at varying acidic conditions. Both the swelling rate and swelling ratio of glycol chitosan hydrogels were higher than those of chitosan hydrogels. Swelling behaviors were significantly affected by not only foaming/drying methods but also crosslinking density, as the sizes and structures of pores generated were highly dependent on those preparation conditions. The prepared superporous hydrogels were highly sensitive to pH of swelling media, and showed reversible swelling and de-swelling behaviors maintaining their mechanical stability. The degradation kinetics in simulated gastric fluid was also studied.

  9. Gas retention and release behavior in Hanford double-shell waste tanks

    SciTech Connect

    Meyer, P.A.; Brewster, M.E.; Bryan, S.A.

    1997-05-01

    This report describes the current understanding of flammable gas retention and release in Hanford double-shell waste tanks AN-103, AN-104, AN-105, AW-101, SY-101, and SY-103. This knowledge is based on analyses, experimental results, and observations of tank behavior. The applicable data available from the void fraction instrument, retained gas sampler, ball rheometer, tank characterization, and field monitoring are summarized. Retained gas volumes and void fractions are updated with these new data. Using the retained gas compositions from the retained gas sampler, peak dome pressures during a gas burn are calculated as a function of the fraction of retained gas hypothetically released instantaneously into the tank head space. Models and criteria are given for gas generation, initiation of buoyant displacement, and resulting gas release; and predictions are compared with observed tank behavior.

  10. Improving utilization of and retention in PMTCT services: Can behavioral economics help?

    PubMed Central

    2013-01-01

    Background The most recent strategic call to action of the World Health Organization sets the elimination of pediatric HIV as a goal. While recent efforts have focused on building infrastructure and ensuring access to high-quality treatment, we must now turn our focus to the behavior change needed to eliminate vertical transmission. We make the case for the application of concepts from the field of behavioral economics to prevention of mother-to-child transmission (PMTCT) programs to more effectively address demand-side issues of uptake and retention. Discussion We introduce five concepts from the field of behavioral economics and discuss their application to PMTCT programs: 1) Mentor mothers who come from similar circumstances as PMTCT patients can serve as social references who provide temporally salient modeling of utilization of services and adherence to treatment. 2) Economic incentives, like cell phone minutes or food vouchers, that reward adherence to PMTCT protocols leverage present bias, the observation that people are generally biased toward immediate versus future awards. 3) Default bias, our preference for the default option, is already being used in many countries in the form of opt-out testing, and could be expanded to all PMTCT programs. 4) We are hardwired to avoid loss more than to pursue an equivalent gain. PMTCT programs can take advantage of loss aversion through the use of commitment contracts that incentivize mothers to return to the clinic in order to avoid both reputational and financial loss. Summary Eliminating vertical transmission of HIV is an ambitious goal. To close the remaining gap, innovations are needed to address demand for PMTCT services. Behavioral economics offers a set of tools that can be engineered into PMTCT programs to increase uptake and improve retention with minimal investment. PMID:24112440

  11. Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

    PubMed Central

    Gardner, Mona; Rosell, Mary; Myers, Edith M.

    2013-01-01

    C. elegans egg-laying behavior is affected by environmental cues such as osmolarity1 and vibration2. In the total absence of food C. elegans also cease egg-laying and retain fertilized eggs in their uterus3. However, the effect of different sources of food, especially pathogenic bacteria and particularly Enterococcus faecalis, on egg-laying behavior is not well characterized. The egg-in-worm (EIW) assay is a useful tool to quantify the effects of different types of bacteria, in this case E. faecalis, on egg- laying behavior. EIW assays involve counting the number of eggs retained in the uterus of C. elegans4. The EIW assay involves bleaching staged, gravid adult C. elegans to remove the cuticle and separate the retained eggs from the animal. Prior to bleaching, worms are exposed to bacteria (or any type of environmental cue) for a fixed period of time. After bleaching, one is very easily able to count the number of eggs retained inside the uterus of the worms. In this assay, a quantifiable increase in egg retention after E. faecalis exposure can be easily measured. The EIW assay is a behavioral assay that may be used to screen for potentially pathogenic bacteria or the presence of environmental toxins. In addition, the EIW assay may be a tool to screen for drugs that affect neurotransmitter signaling since egg-laying behavior is modulated by neurotransmitters such as serotonin and acetylcholine5-9. PMID:24192811

  12. Retention behavior of proton pump inhibitors using immobilized polysaccharide-derived chiral stationary phases with organic-aqueous mobile phases.

    PubMed

    Cirilli, Roberto; Ferretti, Rosella; Gallinella, Bruno; Zanitti, Leo

    2013-08-23

    In the present study, the chromatographic behavior of two immobilized polysaccharide-derived chiral stationary phases (CSPs), the Chiralpak ID-3 and Chiralpak IE-3, under aqueous mobile phases conditions is presented. Four proton pump inhibitors (PPIs) (omeprazole, lansoprazole, pentaprazole and rabeprazole) were selected as test compounds. The effect of the concentration of water in the mobile phase was investigated with respect to its contribution to enantioselectivity and retention. Under acetonitrile-water mobile phase conditions, retention behavior evidenced an interesting pattern. At lower water content, the retention factors decreased with increasing water and at higher water content a reversed trend was observed. These findings support the hypothesis that two retention mechanisms operated successively on the same CSP: the HILIC (with water-poor eluents) and RPLC (with water-rich eluents) modes. The retention factors were minimum in the intermediate region, corresponding to a water concentration of about 20%. Interestingly, the baseline separation of all PPIs investigated was optimized under organic-aqueous mobile phases containing a high water content (from about 50 to 65%). Thus, the dual retention behavior of the PPIs on the Chiralpak ID-3 and Chiralpak IE-3 made it possible to reach greener and harmless enantioselective conditions in a short analysis time.

  13. Activation, Self-management, Engagement, and Retention in Behavioral Health Care

    PubMed Central

    Alegría, Margarita; Carson, Nicholas; Flores, Michael; Li, Xinliang; Shi, Ping; Lessios, Anna Sophia; Polo, Antonio; Allen, Michele; Fierro, Mary; Interian, Alejandro; Jimenez, Aida; La Roche, Martin; Lee, Catherine; Lewis-Fernández, Roberto; Livas-Stein, Gabriela; Safar, Laura; Schuman, Catherine; Storey, Joan; Shrout, Patrick E.

    2015-01-01

    IMPORTANCE Given minority patients’ unequal access to quality care, patient activation and self-management strategies have been suggested as a promising approach to improving mental health care. OBJECTIVE To determine whether the DECIDE (Decide the problem; Explore the questions; Closed or open-ended questions; Identify the who, why, or how of the problem; Direct questions to your health care professional; Enjoy a shared solution) intervention, an educational strategy that teaches patients to ask questions and make collaborative decisions with their health care professional, improves patient activation and self-management, as well as engagement and retention in behavioral health care. DESIGN, SETTING, AND PATIENTS In this multisite randomized clinical trial performed from February 1, 2009, through October 9, 2011 (date of last follow-up interview), we recruited 647 English- or Spanish-speaking patients 18 to 70 years old from 13 outpatient community mental health clinics across 5 states and 1 US territory. A total of 722 patients were included in analyses of secondary outcomes. INTERVENTIONS Three DECIDE training sessions delivered by a care manager vs giving patients a brochure on management of behavioral health. MAIN OUTCOMES AND MEASURES Primary outcomes were patient assessment of activation (Patient Activation Scale) and self-management (Perceived Efficacy in Patient-Physician Interactions). Secondary outcomes included patient engagement (proportion of visits attended of those scheduled) and retention (attending at least 4 visits in the 6 months after the baseline research assessment), collected through medical record review or electronic records. RESULTS Patients assigned to DECIDE reported significant increases in activation (mean β = 1.74, SD = 0.58; P = .003) and self-management (mean β = 2.42, SD = 0.90; P = .008) relative to control patients, but there was no evidence of an effect on engagement or retention in care. CONCLUSIONS AND RELEVANCE The

  14. Corrosion behavior of dental alloys used for retention elements in prosthodontics.

    PubMed

    Nierlich, Judith; Papageorgiou, Spyridon N; Bourauel, Christoph; Hültenschmidt, Robert; Bayer, Stefan; Stark, Helmut; Keilig, Ludger

    2016-06-01

    The purpose of this study was to investigate the corrosion behavior of 10 different high noble gold-based dental alloys, used for prosthodontic retention elements, according to ISO 10271. Samples of 10 high-noble and noble gold-based dental alloys were subjected to: (i) static immersion tests with subsequent analysis of ion release for eight different elements using mass spectrometry; (ii) electrochemical tests, including open-circuit potential and potentiodynamic scans; and (iii) scanning electron microscopy, followed by energy-dispersive X-ray microscopy. The results were analyzed using one-way ANOVA and Sidak multiple-comparisons post-hoc test at a level of significance of α = 0.05. Significant differences were found among the 10 alloys studied for all ions (P < 0.001). The potentiodynamic analysis showed values from -82.5 to 102.8 mV for the open-circuit potential and from 566.7 to 1367.5 mV for the breakdown potential. Both the open-circuit and the breakdown potential varied considerably among these alloys. Scanning electron microscopy analysis confirmed the existence of typically small-diameter corrosion defects, whilst the energy-dispersive X-ray analysis found no significant alteration in the elemental composition of the alloys. The results of this study reveal the variability in the corrosive resistance among the materials used for retention elements in prosthodontics.

  15. The effect of A teacher questioning strategy training program on teaching behavior, student achievement, and retention

    NASA Astrophysics Data System (ADS)

    Otto, Paul B.; Schuck, Robert F.

    The use of questions in the classroom has been employed throughout the recorded history of teaching. One still hears the term Socratic method during discussions of questioning procedures. The use of teacher questions is presently viewed as a viable procedure for effective instruction. This study was conducted to investigate the feasibility of training teachers in the use of a questioning technique and the resultant effect upon student learning. The Post-Test Only Control Group Design was used in randomly assigning teachers and students to experimental and control groups. A group of teachers was trained in the use of a specific questioning technique. Follow-up periodic observations were made of questioning technique behavior while teaching science units to groups of students. Post-unit achievement tests were administered to the student groups to obtain evidence of a relationship between the implementation of specific types of teacher questions and student achievement and retention. Analysis of observation data indicated a higher use of managerial and rhetorical questions by the control group than the experimental group. The experimental group employed a greater number of recall and data gathering questions as well as higher order data processing and data verification type questions. The student posttest achievement scores for both units of instruction were greater for the experimental groups than for the control groups. The retention scores for both units were Beater for the experimental groups than for the control groups.

  16. Cognitive impairment, retention and abstinence among cocaine abusers in cognitive-behavioral treatment.

    PubMed

    Aharonovich, Efrat; Nunes, Edward; Hasin, Deborah

    2003-08-20

    Cognitive-behavioral therapy (CBT) depends on adequate cognitive functioning in patients, but prolonged cocaine use may impair cognitive functioning. Therefore, cognitive impairment may impede the ability of cocaine abusers to benefit from CBT. To begin to address this issue, we investigated the relationship between cognitive impairment and two treatment outcomes, therapy completion and abstention. Eighteen carefully screened non-depressed cocaine-dependent patients in a psychopharmacological clinical trial were administered the MicroCog computerized battery to assess cognitive performance at treatment entry. T-tests were used to compare cognitive functioning between completers (patients remaining in treatment at least 12 weeks) and dropouts. The results indicated that treatment completers had demonstrated significantly better cognitive performance at baseline than patients who dropped out of treatment. Cognitive domains that significantly distinguished between treatment completers and dropouts were attention, mental reasoning and spatial processing. This study provides preliminary evidence that cognitive impairments may decrease treatment retention and abstinence in CBT of cocaine dependence.

  17. Arsenic retention and transport behavior in the presence of typical anionic and nonionic surfactants.

    PubMed

    Liang, Chuan; Wang, Xianliang; Peng, Xianjia

    2016-01-01

    The massive production and wide use of surfactants have resulted in a large amount of surfactant residuals being discharged into the environment, which could have an impact on arsenic behavior. In the present study, the influence of the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and nonionic surfactant polyethylene glycol octylphenyl ether (Triton X-100) on arsenic behavior was investigated in batch and column tests. The presence of SDBS and Triton X-100 reduced arsenic retention onto ferrihydrite (FH), enhanced arsenic transport through FH coated sand (FH-sand) columns and promoted arsenic release from the FH surface. With coexisting surfactants in solution, the equilibrium adsorbed amount of arsenic on FH decreased by up to 29.7% and the adsorption rate decreased by up to 52.3%. Pre-coating with surfactants caused a decrease in the adsorbed amount and adsorption rate of arsenic by up to 15.1% and 58.3%, respectively. Because of the adsorption attenuation caused by surfactants, breakthrough of As(V) and As(III) with SDBS in columns packed with FH-sand was 23.8% and 14.3% faster than that in those without SDBS, respectively. In columns packed with SDBS-coated FH-sand, transport of arsenic was enhanced to a greater extent. Breakthrough of As(V) and As(III) was 52.4% and 43.8% faster and the cumulative retention amount was 44.5% and 57.3% less than that in pure FH-sand column systems, respectively. Mobilization of arsenic by surfactants increased with the increase of the initial adsorbed amount of arsenic. The cumulative release amount of As(V) and As(III) from the packed column reached 10.8% and 36.0%, respectively.

  18. Social, structural, behavioral and clinical factors influencing retention in Pre-Exposure Prophylaxis (PrEP) care in Mississippi

    PubMed Central

    Arnold, Trisha; Brinkley-Rubinstein, Lauren; Chan, Philip A.; Perez-Brumer, Amaya; Bologna, Estefany S.; Beauchamps, Laura; Johnson, Kendra; Mena, Leandro; Nunn, Amy

    2017-01-01

    Pre-exposure prophylaxis (PrEP) is a biomedical intervention that can reduce rates of HIV transmission when taken once daily by HIV-negative individuals. Little is understood about PrEP uptake and retention in care among the populations most heavily impacted by the HIV epidemic, particularly among young men who have sex with men (YMSM) in the Deep South. Therefore, this study explored the structural, social, behavioral, and clinical factors that affect PrEP use and retention in care among YMSM in Jackson, Mississippi. Thirty MSM who were prescribed PrEP at an outpatient primary care clinic were interviewed and included 23 men who had been retained in PrEP care and seven who had not been retained. The mean age of participants was 26.6 years. Most (23) participants were African American. Major factors affecting PrEP use and retention in PrEP care included 1) structural factors such as cost and access to financial assistance for medications and clinical services; 2) social factors such as stigma and relationship status; 3) behavioral factors including sexual risk behaviors; and 4) clinical factors such as perceived and actual side effects. Many participants also discussed the positive spillover effects of PrEP use and reported that PrEP had a positive impact on their health. Four of the seven individuals who had not been retained re-enrolled in PrEP care after completing their interviews, suggesting that case management and ongoing outreach can enhance retention in PrEP care. Interventions to enhance retention in PrEP care among MSM in the Deep South will be most effective if they address the complex structural, social, clinical, and behavioral factors that influence PrEP uptake and retention in PrEP care. PMID:28222118

  19. Understanding the Behavioral Determinants of Retention in HIV Care: A Qualitative Evaluation of a Situated Information, Motivation, Behavioral Skills Model of Care Initiation and Maintenance

    PubMed Central

    Fisher, Jeffrey D.; Cunningham, Chinazo O.; Amico, K. Rivet

    2012-01-01

    Abstract The current study provides a qualitative test of a recently proposed application of an Information, Motivation, Behavioral Skills (IMB) model of health behavior situated to the social-environmental, structural, cognitive-affective, and behavioral demands of retention in HIV care. Mixed-methods qualitative analysis was used to identify the content and context of critical theory-based determinants of retention in HIV care, and to evaluate the relative fit of the model to the qualitative data collected via in-depth semi-structured interviews with a sample of inner-city patients accessing traditional and nontraditional HIV care services in the Bronx, NY. The sample reflected a diverse marginalized patient population who commonly experienced comorbid chronic conditions (e.g., psychiatric disorders, substance abuse disorders, diabetes, hepatitis C). Through deductive content coding, situated IMB model-based content was identified in all but 7.1% of statements discussing facilitators or barriers to retention in HIV care. Inductive emergent theme identification yielded a number of important themes influencing retention in HIV care (e.g., acceptance of diagnosis, stigma, HIV cognitive/physical impairments, and global constructs of self-care). Multiple elements of these themes strongly aligned with the model's IMB constructs. The convergence of the results from both sets of analysis demonstrate that participants' experiences map well onto the content and structure of the situated IMB model, providing a systematic classification of important theoretical and contextual determinants of retention in care. Future intervention efforts to enhance retention in HIV care should address these multiple determinants (i.e., information, motivation, behavioral skills) of self-directed retention in HIV care. PMID:22612447

  20. A Comparative Study of the Effect of Behavioral Objectives on Class Performance and Retention in Physical Science.

    ERIC Educational Resources Information Center

    Olsen, Robert Charles; Lockard, J. David

    Presented at the annual meeting of the National Association for Research in Science Teaching (NARST) in April, 1972, in Chicago, this study compared the achievement and retention of ninth grade physical science classes receiving instruction with a prior knowledge of behavioral objectives with ninth grade classes taught the same material without…

  1. Prediction of salt effects on protein phase behavior by HIC retention and thermal stability.

    PubMed

    Baumgartner, Kai; Großhans, Steffen; Schütz, Juliane; Suhm, Susanna; Hubbuch, Jürgen

    2016-09-05

    In the biopharmaceutical industry it is mandatory to know and ensure the correct protein phase state as a critical quality attribute in every process step. Unwanted protein precipitation or crystallization can lead to column, pipe or filter blocking. In formulation, the formation of aggregates can even be lethal when injected into the patient. The typical methodology to illustrate protein phase states is the generation of protein phase diagrams. Commonly, protein phase behavior is shown in dependence of protein and precipitant concentration. Despite using high-throughput methods for the generation of phase diagrams, the time necessary to reach equilibrium is the bottleneck. Faster methods to predict protein phase behavior are desirable. In this study, hydrophobic interaction chromatography retention times were correlated to crystal size and form. High-throughput thermal stability measurements (melting and aggregation temperatures), using an Optim(®)2 system, were successfully correlated to glucose isomerase stability. By using hydrophobic interaction chromatography and thermal stability determinations, glucose isomerase conformational and colloidal stability were successfully predicted for different salts in a specific pH range.

  2. Retention behavior of phenols, anilines, and alkylbenzenes in liquid chromatographic separations using subcritical water as the mobile phase.

    PubMed

    Yang, Y; Jones, A D; Eaton, C D

    1999-09-01

    The unique characteristic of subcritical water is its widely tunable physical properties. For example, the polarity (measured by dielectric constant) of water is significantly decreased by raising water temperature. At temperatures of 200-250 °C (under moderate pressure to keep water in the liquid state), the polarity of pure water is similar to that of pure methanol or acetonitrile at ambient conditions. Therefore, pure subcritical water may be able to serve as the mobile phase for reversed-phase separations. To investigate the retention behavior in subcritical water separation, the retention factors of BTEX (benzene, toluene, ethylbenzene, and m-xylene), phenol, aniline, and their derivatives have been determined using subcritical water, methanol/water, and acetonitrile/water systems. Subcritical water separations were also performed using alumina, silica-bonded C18, and poly(styrene-divinylbenzene) columns to study the influence of the stationary phase on analyte retention under subcritical water conditions.

  3. Assessment of Lipophilicity Indices Derived from Retention Behavior of Antioxidant Compounds in RP-HPLC.

    PubMed

    Sima, Ioana Anamaria; Kot-Wasik, Agata; Wasik, Andrzej; Namieśnik, Jacek; Sârbu, Costel

    2017-03-29

    Reverse phase high pressure liquid chromatography was employed in order to evaluate the lipophilicity of antioxidant compounds from different classes, such as phenolic acids, flavanones, flavanols, flavones, anthocyanins, stilbenes, xantonoids, and proanthocyanidins. The retention time of each compound was measured using five different HPLC columns: RP18 (LiChroCART, Purosphere RP-18e), C8 (Zorbax, Eclipse XDBC8), C16-Amide (Discovery RP-Amide C16), CN100 (Saulentechnik, Lichrosphere), and pentafluorophenyl (Phenomenex, Kinetex PFP), and the mobile phase consisted of methanol and water (0.1% formic acid) in different proportions. The measurements were conducted at two different column temperatures, room temperature (22 °C) and, in order to mimic the environment from the human body, 37 °C. Furthermore, principal component analysis (PCA) was used to obtain new lipophilicity indices and holistic lipophilicity charts. Additionally, highly representative depictions of the chromatographic behavior of the investigated compounds and stationary phases at different temperatures were obtained using two new chemometric approaches, namely two-way joining cluster analysis and sum of ranking differences.

  4. Gas retention and release behavior in Hanford single-shell waste tanks

    SciTech Connect

    Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

    1996-12-01

    This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large ({approximately}100 m{sup 3}) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given.

  5. The Effect of Internal Salary Increment Distributions on Retention Behaviors of Western New York Teachers

    ERIC Educational Resources Information Center

    Patterson, Michele M.

    2013-01-01

    This is a study of district internal salary distribution practices and its effect on retention. The study is a replication study as recommended by Jacobson (1986) and Lankford and Wyckoff (1997) whereby their research shows the prevalence of "back loading" and ineffectiveness relative to retention. In the case of this study, the…

  6. Retention behavior of lipids in reversed-phase ultrahigh-performance liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Ovčačíková, Magdaléna; Lísa, Miroslav; Cífková, Eva; Holčapek, Michal

    2016-06-10

    Reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) method using two 15cm sub-2μm particles octadecylsilica gel columns is developed with the goal to separate and unambiguously identify a large number of lipid species in biological samples. The identification is performed by the coupling with high-resolution tandem mass spectrometry (MS/MS) using quadrupole - time-of-flight (QTOF) instrument. Electrospray ionization (ESI) full scan and tandem mass spectra are measured in both polarity modes with the mass accuracy better than 5ppm, which provides a high confidence of lipid identification. Over 400 lipid species covering 14 polar and nonpolar lipid classes from 5 lipid categories are identified in total lipid extracts of human plasma, human urine and porcine brain. The general dependences of relative retention times on relative carbon number or relative double bond number are constructed and fit with the second degree polynomial regression. The regular retention patterns in homologous lipid series provide additional identification point for UHPLC/MS lipidomic analysis, which increases the confidence of lipid identification. The reprocessing of previously published data by our and other groups measured in the RP mode and ultrahigh-performance supercritical fluid chromatography on the silica column shows more generic applicability of the polynomial regression for the description of retention behavior and the prediction of retention times. The novelty of this work is the characterization of general trends in the retention behavior of lipids within logical series with constant fatty acyl length or double bond number, which may be used as an additional criterion to increase the confidence of lipid identification.

  7. A Computer-Based Undergraduate Exercise Using Internet-Accessible Simulation Software for the Study of Retention Behavior and Optimization of Separation Conditions in Ion Chromatography

    ERIC Educational Resources Information Center

    Haddad, Paul R.; Shaw, Matthew J.; Madden, John E.; Dicinoski, Greg W.

    2004-01-01

    The ability to scan retention data over a wide range of eluent composition opens up the possibility of a computerized selection of the optimal separation conditions. The major characteristics of retention behavior, peak-shape effects and pH effects evident in ion chromatography (IC) using common stationary phases and eluents are illustrated.

  8. Statistical learning of peptide retention behavior in chromatographic separations: a new kernel-based approach for computational proteomics

    PubMed Central

    Pfeifer, Nico; Leinenbach, Andreas; Huber, Christian G; Kohlbacher, Oliver

    2007-01-01

    Background High-throughput peptide and protein identification technologies have benefited tremendously from strategies based on tandem mass spectrometry (MS/MS) in combination with database searching algorithms. A major problem with existing methods lies within the significant number of false positive and false negative annotations. So far, standard algorithms for protein identification do not use the information gained from separation processes usually involved in peptide analysis, such as retention time information, which are readily available from chromatographic separation of the sample. Identification can thus be improved by comparing measured retention times to predicted retention times. Current prediction models are derived from a set of measured test analytes but they usually require large amounts of training data. Results We introduce a new kernel function which can be applied in combination with support vector machines to a wide range of computational proteomics problems. We show the performance of this new approach by applying it to the prediction of peptide adsorption/elution behavior in strong anion-exchange solid-phase extraction (SAX-SPE) and ion-pair reversed-phase high-performance liquid chromatography (IP-RP-HPLC). Furthermore, the predicted retention times are used to improve spectrum identifications by a p-value-based filtering approach. The approach was tested on a number of different datasets and shows excellent performance while requiring only very small training sets (about 40 peptides instead of thousands). Using the retention time predictor in our retention time filter improves the fraction of correctly identified peptide mass spectra significantly. Conclusion The proposed kernel function is well-suited for the prediction of chromatographic separation in computational proteomics and requires only a limited amount of training data. The performance of this new method is demonstrated by applying it to peptide retention time prediction in IP

  9. Retention behavior of isomeric triacylglycerols in silver-ion HPLC: effects of mobile phase composition and temperature.

    PubMed

    Lísa, Miroslav; Denev, Rumen; Holčapek, Michal

    2013-09-01

    A systematic study of the retention behavior of isomeric triacylglycerols (TGs) in silver-ion HPLC on a ChromSpher Lipids column has been performed between 10 to 40°C using the most widespread hexane- and dichloromethane-based mobile phases. The randomization of mono-acyl TG standards and the random esterification of glycerol with fatty acids are employed to produce mixtures of TG isomers. The mobile phase composition has no influence on the general retention pattern, but significant differences in the retention order of double bond (DB) positional isomers in hexane and dichloromethane mobile phases are described and compared with the previous literature data. Saturated TGs with fatty acyl chain length from C7:0 to C22:0 are partially separated using the hexane mobile phase but not at all with the dichloromethane mobile phase. The hexane mobile phase enables at least partial resolution of TG regioisomers with up to seven DBs, while the resolution of only ALA/AAL and ALnA/AALn isomers is achieved with the dichloromethane mobile phase. The effect of temperature differs significantly depending on the mobile phase composition. Retention times of TGs increase with increasing temperature in the hexane mobile phase, while an opposite effect is observed for the dichloromethane mobile phase.

  10. What Factors Determine the Retention Behavior of Engineered Nanomaterials in Saturated Porous Media?

    PubMed

    Goldberg, Eli; McNew, Coy; Scheringer, Martin; Bucheli, Thomas D; Nelson, Peter; Hungerbühler, Konrad

    2017-02-16

    A fundamental problem associated with the vertical transport of engineered nanomaterials (ENMs) in saturated porous media is the occurrence of nonexponential, for example, nonmonotonic or linearly increasing, retention profiles. To investigate this problem, we compiled an extensive database of ENMs transport experiments in saturated porous media. Using this database we trained a decision tree that shows the order of importance, and range of influence, of the physicochemical factors that control the retention profile shape. Our results help identify domains where current particle-transport models can be used, but also highlight, for the first time, large domains where nonexponential retention profiles dominate and new approaches are needed to understand ENM transport. Importantly, highly advective flow and high ENM influent mass can mask the influence of other physicochemical factors on the retention profile shape; notably, this occurs in 50% of the experiments investigated. Where the relationship between physicochemical factors and retention profile shape can be investigated in detail, our results agree with, and provide validation for, the current understanding of how these factors influence ENM transport.

  11. Effect of boundary conditions on measured water retention behavior within soils

    NASA Astrophysics Data System (ADS)

    Galindo-torres, S.; Scheuermann, A.; Pedroso, D.; Li, L.

    2013-12-01

    conducted to examine how the fluids are distributed inside the porous medium. This distribution is quantified by the measurement of the interfacial area which behaves also differently between the two configurations. Hassanizadeh proposed an unique relation among saturation, suction and interfacial area, which has been validated experimentally [4]. However we found that such relation is not 'unique' and instead depends on the flow and boundary conditions. While future experimental tests on these results need to be carried out, the simulated SWCC behaviors raise serious questions about the current experimental set-up for measuring the soil water retention characteristics. References. 1. Serrano, S.E., Modeling infiltration with approximate solutions to Richard's equation. Journal of Hydrologic Engineering, 2004. 9(5): p. 421-432. 2. Galindo-Torres, S.A., et al., A Lattice Boltzmann model for studying transient effects during imbibition-drainage cycles in unsaturated soils. Computer Physics Communications, 2013. 184(4): p. 1086-1093. 3. Drake, S.S., D.M. O'Carroll, and J.I. Gerhard, Wettability contrasts between fresh and weathered diesel fuels. Journal of contaminant hydrology, 2012. 4. Culligan, K.A., et al., Interfacial area measurements for unsaturated flow through a porous medium. Water Resources Research, 2004. 40(12).

  12. Retention behavior on aminoethyl-modified poly(p-phenylene terephthalamide) fiber stationary phases in gas chromatography.

    PubMed

    Shirai, Shingoro; Saito, Yoshihiro; Sakurai, Yasuhiro; Ueta, Ikuo; Jinno, Kiyokatsu

    2010-01-01

    Surface derivatization of Kevlar, poly(p-phenylene terephthalamide), fiber has been studied along with the evaluation of the surface characteristics of the chemically-modified fiber as the stationary phase in packed-capillary gas chromatography (GC). Several experimental parameters in the derivatization reaction have been optimized, and the retention behavior of the surface-derivatized fibrous stationary phase has been investigated using various standard solutes, such as alkanes, alcohols and alkylbenzenes. By introducing aminoethyl functional groups onto the surface of the fibrous material, a specific selectivity for polar solutes has been observed.

  13. Retention behavior of isomeric polycyclic aromatic sulfur heterocycles in reversed-phase liquid chromatography.

    PubMed

    Wilson, Walter B; Sander, Lane C; de Alda, Miren Lopez; Lee, Milton L; Wise, Stephen A

    2016-08-26

    Retention indices for 70 polycyclic aromatic sulfur heterocycles (PASHs) were determined using reversed-phase liquid chromatography (LC) on a monomeric and a polymeric C18 stationary phase. Molecular shape parameters [length, breadth, thickness (T), and length-to-breadth ratio (L/B)] were calculated for all the compounds studied. Correlations between the retention on the polymeric C18 phase and PASH geometry (L/B and T) were investigated for six specific PASH isomer groups with molecular mass (MM) 184Da, 234Da, 258Da, 284Da, 334Da, and 384Da. Similar to previous studies for polycyclic aromatic hydrocarbons (PAHs), PASH elution order on the polymeric C18 phase was generally found to follow increasing L/B values. Correlation coefficients for retention vs L/B ranged from r=0.45 (MM 184Da) to r=0.89 (MM 284Da). In the case of smaller PASHs (MM≤258Da), the location of the sulfur atom in the bay-region of the structure resulted in later than expected elution of these isomers based on L/B. In the case of the larger PASHs (MM≥284Da), nonplanarity had a significant influence on earlier than predicted elution based on L/B values.

  14. Deuterium implantation into Y2O3-doped and pure tungsten: Deuterium retention and blistering behavior

    NASA Astrophysics Data System (ADS)

    Zhao, M.; Jacob, W.; Manhard, A.; Gao, L.; Balden, M.; von Toussaint, U.; Zhou, Z.

    2017-04-01

    The blistering and near-surface deuterium retention of a Y2O3-doped tungsten (W) and two different pure W grades were studied after exposure to deuterium (D) plasma at elevated temperatures (370, 450 and 570 K). Samples were exposed to a deuterium fluence of 6 × 1024 D m-2 applying a moderate ion flux of about 9 × 1019 D m-2 s-1 at an ion energy of 38 eV/D. Morphological modifications at the surface were analyzed by confocal laser scanning microscopy and scanning electron microscopy. The D depth profiles and the accumulated D inventories within the topmost 8 μm were determined by nuclear reaction analysis. Blistering and deuterium retention were strongly dependent on the implantation temperature. In addition, blistering was sensitively influenced by the used tungsten grade, although the total amount of retained D measured by nuclear reaction analysis was comparable. Among the three different investigated tungsten grades, Y2O3-doped W exhibited the lowest degree of surface modification despite a comparable total D retention.

  15. Capacity retention behavior and morphology evolution of SixGe1-x nanoparticles as lithium-ion battery anode.

    PubMed

    Ge, Mingyuan; Kim, Seongbeom; Nie, Anmin; Shahbazian-Yassar, Reza; Mecklenburg, Matthew; Lu, Yunhao; Fang, Xin; Shen, Chenfei; Rong, Jiepeng; Yi Park, Song; Suk Kim, Dong; Young Kim, Jin; Zhou, Chongwu

    2015-01-26

    Engineering silicon into nanostructures has been a well-adopted strategy to improve the cyclic performance of silicon as a lithium-ion battery anode. Here, we show that the electrode performance can be further improved by alloying silicon with germanium. We have evaluated the electrode performance of SixGe1-x nanoparticles (NPs) with different compositions. Experimentally, SixGe1-x NPs with compositions approaching Si50Ge50 are found to have better cyclic retention than both Si-rich and Ge-rich NPs. During the charge/discharge process, NP merging and Si-Ge homogenization are observed. In addition, a distinct morphology difference is observed after 100 cycles, which is believed to be responsible for the different capacity retention behavior. The present study on SixGe1-x alloy NPs sheds light on the development of Si-based electrode materials for stable operation in lithium-ion batteries (e.g., through a comprehensive design of material structure and chemical composition). The investigation of composition-dependent morphology evolution in the delithiated Li-SiGe ternary alloy also significantly broadens our understanding of dealloying in complex systems, and it is complementary to the well-established understanding of dealloying behavior in binary systems (e.g., Au-Ag alloys).

  16. The value of spontaneous alternation behavior (SAB) as a test of retention in pharmacological investigations of memory.

    PubMed

    Hughes, Robert N

    2004-09-01

    Because of its reliance on memory, the tendency for rats, mice and other animals to alternate successive choices of T- or Y-maze arms has assumed considerable popularity in pharmacological studies of spatial memory as a quick and simple measure of retention that avoids the need for extensive training and the use of conventional reinforcers. Two forms of this tendency have been utilized, namely two-trial and continuous spontaneous alternation behavior (SAB). However, as the behavior can also reflect drug-related changes in sensory/attentional, motivational and performance processes, SAB should not be unquestionably accepted as a measure of memory alone. While assessments of post-acquisition drug effects on longer term memory may be possible through the appropriate timing of drug administration, this is more problematic if SAB is used as a measure of shorter term memory. Even though SAB can be a useful index of responsiveness to novelty, its value as a measure of retention is less certain. In this latter respect, a possible alternative to SAB testing might be the recently developed form of the related procedure, responsiveness to change.

  17. Prevention des Toxicomanies Aupres des Filles avec des Problemes de Comportement: Effets a Court Terme (Prevention of Drug Addiction in Girls with Behavior Problems: Short-Term Effects).

    ERIC Educational Resources Information Center

    Vitaro, Frank; And Others

    1992-01-01

    This article, written in French, describes and evaluates the first phase of a program to prevent drug addiction among 110 fifth-grade girls with behavior problems in Montreal (Quebec, Canada). Evaluation of the instructional program showed positive results for student knowledge level, attitudes, and behaviors and supported program continuation…

  18. Retention behavior of alkyl-substituted polycyclic aromatic sulfur heterocycles in reversed-phase liquid chromatography.

    PubMed

    Wilson, Walter B; Sander, Lane C; de Alda, Miren Lopez; Lee, Milton L; Wise, Stephen A

    2016-08-26

    Retention indices for 79 alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) were determined by using reversed-phase liquid chromatography (LC) on a monomeric and polymeric octadecylsilane (C18) stationary phase. Molecular shape parameters [length, breadth, thickness (T), and length-to-breadth ratio (L/B)] were calculated for all the compounds studied. Based on separations of isomeric methylated polycyclic aromatic hydrocarbons on polymeric C18 phases, alkyl-substituted PASHs are expected to elute based on increasing L/B ratios. However, the correlation coefficients had a wide range of values from r=0.43 to r=0.93. Several structural features besides L/B ratios were identified to play an important role in the separation mechanism of PASHs on polymeric C18 phases. First, the location of the sulfur atom in a bay-like-region results in alkylated-PASHs being more retentive than non-bay-like-region alkylated-PASHs, and they elute later than expected based on L/B value. Second, the placement of the alkyl group in the k region of the structure resulted in a later elution than predicted by L/B. Third, highly nonplanar methyl-PASHs (i.e., 1-Me and 11-MeBbN12T) elute prior to the parent PASH (BbN12T).

  19. TRENDS (Transport and Retention of Nuclides in Dominant Sequences): A code for modeling iodine behavior in containment during severe accidents

    SciTech Connect

    Weber, C.F.; Beahm, E.C.; Kress, T.S.; Daish, S.R.; Shockley, W.E.

    1989-01-01

    The ultimate aim of a description of iodine behavior in severe LWR accidents is a time-dependent accounting of iodine species released into containment and to the environment. Factors involved in the behavior of iodine can be conveniently divided into four general categories: (1) initial release into containment, (2) interaction of iodine species in containment not directly involving water pools, (3) interaction of iodine species in, or with, water pools, and (4) interaction with special systems such as ice condensers or gas treatment systems. To fill the large gaps in knowledge and to provide a means for assaying the iodine source term, this program has proceeded along two paths: (1) Experimental studies of the chemical behavior of iodine under containment conditions. (2) Development of TRENDS (Transport and Retention of Nuclides in Dominant Sequences), a computer code for modeling the behavior of iodine in containment and its release from containment. The main body of this report consists of a description of TRENDS. These two parts to the program are complementary in that models within TRENDS use data that were produced in the experimental program; therefore, these models are supported by experimental evidence that was obtained under conditions expected in severe accidents. 7 refs., 1 fig., 2 tabs.

  20. Effects of comprehensive function of factors on retention behavior of microparticles in gravitational field-flow fractionation.

    PubMed

    Guo, Shuang; Qiu, Bai-Ling; Zhu, Chen-Qi; Yang, Ya-Ya Gao; Wu, Di; Liang, Qi-Hui; Han, Nan-Yin

    2016-09-15

    Gravitational field-flow fractionation (GrFFF) is a useful technique for separation and characterization for micrometer-sized particles. Elution behavior of micrometer-sized particles in GrFFF was researched in this study. Particles in GrFFF channel are subject to hydrodynamic lift forces (HLF), fluid inertial forces and gravity, which drive them to different velocities by carrier flow, resulting in a size-based separation. Effects of ionic strength, flow rate and viscosity as well as methanol were investigated using polystyrene latex beads as model particles. This study is devoted to experimental verification of the effect of every factor and their comprehensive function. All experiments were performed to show isolated influence of every variable factor. The orthogonal design test was used to evaluate various factors comprehensively. Results suggested that retention ratio of particles increases with increasing flow rate or the viscosity of carrier liquid by adjusting external forces acting on particles. In addition, retention ratio increases as ionic strength decreases because of decreased electrostatic repulsion between particles and channel accumulation wall. As far as methanol, there is no general trend due to the change of both density and viscosity. On the basis of orthogonal design test it was found that viscosity of carrier liquid plays a significant role in determining resolution of micrometer-sized particles in GrFFF.

  1. A Study of Middle School Principal Behaviors and Their Impact on Teacher Retention

    ERIC Educational Resources Information Center

    Martin, Todd

    2011-01-01

    This dissertation was designed to investigate the causes behind teacher turnover and the connection between principal behavior, teacher working conditions, and rates of teacher turnover. In particular, this study examined behaviors that teachers in three North Carolina middle schools felt their principals displayed that helped encourage them to…

  2. An Empirical Examination of Outdoor Behavioral Healthcare Field Instructor Job-Related Stress and Retention

    ERIC Educational Resources Information Center

    Marchand, Genevieve; Russell, Keith C.; Cross, Reid

    2009-01-01

    The purpose of this study was to collect and analyze demographic characteristics and job related difficulties experienced by field instructors in outdoor behavioral healthcare programs which utilized wilderness therapy as well as other treatment modalities. Three state-licensed outdoor behavioral healthcare programs in the United States provided a…

  3. COSMO-RS for the prediction of the retention behavior in micellar liquid chromatography based on partition coefficients of non-dissociated and dissociated solutes.

    PubMed

    Mehling, Tanja; Kloss, Linda; Mushardt, Heike; Ingram, Thomas; Smirnova, Irina

    2013-01-18

    Several methods for the description of the retention behavior in micellar liquid chromatography (MLC) were described previously. Thereby, the most common are the linear solvation energy relationships (LSER). However, for the evaluation of the LSER, a number of experimental data are necessary. In this work, the retention data are predicted based on a single data point for a given solute/surfactant combination. The prediction of micelle/water partition coefficients with the COSMO-RS model was evaluated for the nonionic surfactant Brij 35 and the cationic CTAB for 21 solutes. The predicted partition coefficients along with the retention data of a single measurement were combined with a common retention model for the evaluation of partition coefficients. Thus, the description of the retention data based on a minimum of experimental data was realized in this work. The COSMO-RS model appears to be suitable for the flexible and qualitative prediction of the retention data, which is of special benefit, when a large number of solutes are studied. Furthermore, the introduced method is a promising alternative to describe the retention behavior of ionizable solutes, which is of great interest for e.g. pharmaceutical processes and analyses. To evaluate the method, lipophilicity profiles of several solutes were determined with MLC. While for the nonionic surfactant the lipophilicity is similar to the octanol/water system, a contrary phenomenon, namely a significant increase of the partition coefficient with progressive dissociation can be observed with the ionic surfactant. The MLC method proved to be an efficient method for the determination of micelle/water partition coefficients, excluding non-binding and "overbinding" solutes. The introduced COSMO-RS based approach for the estimation of the retention in MLC is especially promising for highly retarding solutes, since it is time and cost saving compared to the experimental determination.

  4. Retention behavior of long chain quaternary ammonium homologues and related nitroso-alkymethylamines

    USGS Publications Warehouse

    Abidi, S.L.

    1985-01-01

    Several chromatographic methods have been utilized to study the retentionbehavior of a homologous series of n-alkylbenzyldimethylammonium chlorides (ABDAC) and the corresponding nitroso-n-alkylmethylamines (NAMA). Linear correlation of the logarithmic capacity factor (k') with the number of carbons in the alkyl chain provides useful information on both gas chromatographic (GC) and high-performance liquid chromatographich (HPLC) retention parameters of unknown components. Under all conditions empolyed, GC methodology has proved effective in achieving complete resolution of the homologous mixture of NMA despite its obvious inadequacy in the separation of E-Z configurational isomers. Conversely, normal-phase HPLC on silica demonstrates that the selectivity (a) value for an E-Z pair is much higher than that for an adjacent homologous pair. In the reversed-phase HPLC study, three different silica-based column systems were examined under various mobile phase conditions. The extent of variation in k' was found to be a function of the organic modifier, counter-ion concentration, eluent pH, nature of counter-ion, and the polarity and type of stationary phase. The k'—[NaClO4] profiles showed similar trends between the ABDAC and the NAMA series, supporting the dipolar electronic structures of the latter compounds. Mobile phase and stationary phase effects on component separation are described. The methodology presented establishes the utility of HPLC separation techniques as versatile analytical tools for practical application.

  5. Different retention behavior of structurally diverse basic and neutral drugs in immobilized artificial membrane and reversed-phase high performance liquid chromatography: comparison with octanol-water partitioning.

    PubMed

    Vrakas, Demetris; Giaginis, Costas; Tsantili-Kakoulidou, Anna

    2006-05-26

    The retention behavior of 43 structurally diverse neutral and basic drugs in immobilized artificial membrane chromatography was investigated and compared to the reversed-phase retention and octanol-water partitioning. IAM chromatography was performed using morpholinepropanesulfonic acid (MOPS) or phosphate buffer saline (PBS) at pH 7.4 as the aqueous component of the mobile phase. The differences in the retention factors were attributed to increased electrostatic interactions in the MOPS environment, dependent on the fraction of charged species. Electrostatic interactions were found to play a key role in the relationships with reversed-phase retention factors determined under two different mobile phase conditions as well as in the relationships with lipophilicity data. IAM retention factors correlated better with octanol-water partition coefficients log P than with log D(7.4), as a result of the contribution of electrostatic forces in IAM retention. With log D(7.4) the relationships were improved when the fraction of charged species was taken into consideration. In any case the regression coefficient of log P or log D(7.4) was considerably lower than 1 reflecting the reduced hydrophobic environment of the IAM stationary phase. The different data sets were submitted to principal component analysis for further exploration of their similarities/dissimilarities.

  6. Forced egg retention and oviposition behavior of malaria, dengue and filariasis vectors to a topical repellent diethyl-phenylacetamide.

    PubMed

    Seenivasagan, T; Iqbal, S Thanvir; Guha, Lopamudra

    2015-07-01

    Egg retention and oviposition behavior of four species of mosquito vectors viz., Anopheles stephensi, Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus to a topical insect repellent diethyl-phenylacetamide (DEPA) at 0.1-1000 mg/L was investigated under laboratory conditions. Based on oviposition activity indices, DEPA demonstrated concentration dependent oviposition deterrent effect to A. stephensi (-0.18 to -0.97), A. aegypti (-0.18 to -0.91) and A. albopictus (-0.50 to -0.98) females. In contrast, positive oviposition response by C. quinquefasciatus (+0.39 and +0.70) was observed respectively at 0.1 and 1 ppm, while 10 ppm of DEPA on water received 50% lesser egg rafts than control. Gravid Culex females laid no egg rafts at 100 and 1000 ppm DEPA treated bowls effecting 100% oviposition deterrence. Test mosquito females deposited most of their eggs (> 90%) in the absence of repellent odour, while DEPA odour on water surface forced them to retain huge numbers of eggs. Females of A. aegypti, A. albopictus and A. stephensi retained 49, 67 and 50% of total eggs, respectively throughout the experiment. Egg retention by Culex females due to DEPA on the water surface was ca. 65%, equivalent to 4 egg rafts. Therefore, DEPA at lower concentrations could effectively disturb the oviposition by these vectors. Application of repellents in small water bodies would help in reducing the population build up of mosquitoes near human households and could be useful in the integrated management of mosquito vectors.

  7. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS

    SciTech Connect

    Lebone T. Moeti; Ramanathan Sampath

    2001-09-28

    This final technical report describes work performed under DOE Grant No. DE-FG26-97FT97278 during the period October 01, 1997 to August 31, 2001 which covers the total performance period of the project. During this period, detailed information on optimal salinity, temperature, emulsion morphologies, effectiveness for surfactant retention and oil recovery was obtained for an Alcohol Ethoxycarboxylate (AEC) surfactant to evaluate its performance in flooding processes. Tests were conducted on several AEC surfactants and NEODOX (23-4) was identified as the most suitable hybrid surfactant that yielded the best proportion in volume for top, middle, and bottom phases when mixed with oil and water. Following the selection of this surfactant, temperature and salinity scans were performed to identify the optimal salinity and temperature, and the temperature and salinity intervals in which all three phases coexisted. NEODOX 23-4 formed three phases between 4 and 52.5 C. It formed an aqueous rich microemulsion phase at high temperatures and an oleic rich microemulsion phase at low temperatures--a characteristic of the ionic part of the surfactant. The morphology measurement system was set-up successfully at CAU. The best oil/water/surfactant system defined by the above phase work was then studied for emulsion morphologies. Electrical conductivities were measured for middle and bottom phases of the NEODOX 23-4/dodecane/10mM water system and by mixing measured volumes of the middle phase into a fixed volume of the bottom phase and vice versa at room temperature. Electrical conductivity of the mixture decreased as the fraction of volume of the middle phase was increased and vice versa. Also inversion phenomena was observed. These experiments were then repeated for bottom/middle (B/M) and middle/bottom (M/B) conjugate pair phases at 10, 15, 25, 30, 35, 40, and 45 C. Electrical conductivity measurements were then compared with the predictions of the conductivity model developed in

  8. INVESTIGATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND CONDENSATE RECOVERY FOR CONDENSATE/WATER/ETHANOL MIXTURES

    SciTech Connect

    Ramanathan Sampath

    2003-10-01

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period April 01, 2003 to September 30, 2003 which covers the second six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. During this reporting period, salinity scans were completed for 0, 5, 10, 20, 50, 100, 250, 500, and 1000 mM salt concentrations at room temperature to identify optimal salinity intervals in which all three phases coexist for this system. Temperature scans are in progress at Morehouse College to identify the optimal temperature, and the temperature intervals in which all three phases coexist for this system. Coreflooding experiments are being conducted by our industrial partner in this project, Surtek, CO, to measure the effectiveness for surfactant retention and condensate recovery in flooding processes. Review of the current literature in the subject area, and modeling efforts that were established in our previous studies to predict electrical conductivities and inversion phenomena was continued from the previous reporting period. Based on the review a computer model to predict electrical conductivities of the ethylbenzene (that has the equivalent carbon number of the condensate)/water/ethanol system is being developed.

  9. Retention behavior of C1-C6 aliphatic monoamines on anion-exchange and polymethacrylate resins with heptylamine as eluent.

    PubMed

    Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae Jeong; Lee, Kwang-Pill

    2004-06-11

    Retention behavior of C1-C6, aliphatic monoamines (methylamine, ethylamine, propylamine, butylamine, amylamine and hexylamine) on columns (150 mm x 6 mm i.d.) packed with various anion-exchange resins (styrene-divinylbenzene (PS-DVB) copolymer-based strongly basic anion-exchange resin: TSKgel SAX, polymethacrylate-based strongly basic anion-exchange resin: TSKgel SuperQ-5PW and polymethacrylate-based weakly basic anion-exchange resin: TSKgel DEAE-5PW) and unfunctionized polymethacrylate resins (TSKgel G5000PW and TSKgel G3000PWXL) was investigated with basic solutions (sodium hydroxide and heptylamine) as the eluents. Due to strongly electrostatic repulsion (ion-exclusion effect) between these anion-exchange resins and these amines, peak resolution between these amines on these anion-exchange resin columns was unsatisfactory with both sodium hydroxide and heptylamine as the eluents. In contrast, these polymethacrylate resins were successfully applied as the stationary phases for the separation of these C1-C6 amines with heptylamine as eluent, because of both small hydrophobicity and small cation-exchange ability of these resins. Excellent simultaneous separation, highly sensitive conductimetric detection and symmetrical peaks for these C1-C6 amines were achieved on the TSKgel G3000PWXL column in 35 min with 5 mM heptylamine at pH 11.1 as the eluent.

  10. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS

    SciTech Connect

    LEBONE MOETI; RAMANATHAN SAMPATH

    1998-11-01

    This semi-annual technical progress report describes work performed at Clark Atlanta University under DOE Grant No. DE-FG26-97FT97278 during the period April 01, 1998 to October 01, 1998 which covers the second six months of the project. Presently work is in progress at the EOR Laboratory, Clark Atlanta University (CAU), to characterize phase and emulsion behavior for a novel, hybrid (ionic/non-ionic), alcohol ethoxycarboxylate surfactant (NEODOX 23-4 from Shell Chemical Company). During this reporting period, salinity scans were completed for 0, 5, 10, 20, 50, 100, 250, 500, 1000, 2000, 3000, 4000, 5000, and 6000 mM salt concentrations at 20, 25, and 30 °C to identify optimal salinity intervals in which all three phases coexist for this surfactant. Temperature scans were also performed at 20 mM salt concentration for various surfactant concentrations ranging from 0 to 60 weight percent at temperatures ranging from 5 to 50 °C to identify optimal surfactant concentration and temperature intervals in which all three phases coexist. This resulted in an "alpha" curve with an interval of temperature in which all three phases coexisted. Presently, temperature scans are being repeated at 100, 250, 500, 1000, and 5000 mM salt concentrations to see whether increase in salt concentration has any effect on the temperature interval. This will provide us better understanding and experimental control of the many variables involved in this research in the future. Following completion of the temperature scans, phase studies will be conducted at CAU, and coreflooding experiments at the facility of our industrial partner, Surtek, Golden, CO.

  11. Factors Affecting Retention Behavior: A Model To Predict At-Risk Students. AIR 1997 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Sadler, William E.; Cohen, Frederic L.; Kockesen, Levent

    This paper describes a methodology used in an on-going retention study at New York University (NYU) to identify a series of easily measured factors affecting student departure decisions. Three logistic regression models for predicting student retention were developed, each containing data available at three distinct times during the first…

  12. Phenomenon of dual- and single-retention behaviors of solutes and its validation by computational simulation in linear programmed temperature gas chromatography.

    PubMed

    Wu, Liejun; Duan, Xiaojuan; Liu, Chuanyu; Zhang, Guangxiang; Li, Qing X

    2016-07-01

    The current theory of programmed temperature gas chromatography considers that solutes are focused by the stationary phase at the column head completely and does not explicitly recognize the different effects of initial temperature (To ) and heating rate (rT ) on the retention time or temperature of a homologue series. In the present study, n-alkanes, 1-alkenes, 1-alkyl alcohols, alkyl benzenes, and fatty acid methyl esters standards were used as model chemicals and were separated on two nonpolar columns, one moderately polar column and one polar column. Effects of To and rT on the retention of nonstationary phase focusing solutes can be explicitly described with isothermal and cubic equation models, respectively. When the solutes were in the stationary phase focusing status, the single-retention behavior of solutes was observed. It is simple, dependent upon rT only and can be well described by the cubic equation model that was visualized through four sequential slope analyses. These observed dual- and single-retention behaviors of solutes were validated by various experimental data, physical properties, and computational simulation.

  13. Role of air on local water retention behavior in the shallow heterogeneous vadose zone

    NASA Astrophysics Data System (ADS)

    Sakaki, T.; Limsuwat, A.; Illangasekare, T. H.

    2009-12-01

    simple heterogeneous column. The column was packed using two sands to form three layers where the coarser sand was sandwitched by two layers of a finer sand. In each layer, soil moisture, water pressure and air pressure were monitored. The soil was initially saturated and suction at the bottom was gradually increased to induce wetting fluid drainage, and followed by a wetting cycle. In the drainage cycle, the coarse middle layer did not drain until air front reached the bottom of the top fine layer. Once the air front reached the fine-coarse interface, air was quickly pulled into the coarse layer. The results showed that the newly developed hydrophobic material showed very small time lag and captured the abrupt air pressure change in the wet soil. In the wetting cycle, we observed positive air pressure which indicated entrapment of air and its compression as wetting proceeded. This behavior cannot be evaluated properly without the rapid measurement of air pressure. The method is currently being applied in a large 2D vertical aquifer with a structured heterogeneity to investigate how air pathways are formed under various flux/temperature conditions at the soil surface.

  14. The persistence of the effect of methylglucamine orotate on the retention of a learned behavior in the rat.

    PubMed

    Rüthrich, H L; Wetzel, W; Matthies, H

    1980-01-01

    The effects of methylglucamine orotate (MGO) on the retention of a brightness discrimination in rats was investigated after different intervals between treatment and acquisition, 225 mg MGO/kg were injected intraperitoneally each day over a period of 10 days. Control animals received a NaCl-solution. After drug-free intervals of 5 days or 12 days respectively, MGO-treated rats showed significantly better retention of the learned reaction than controls, whereas their training performance was not influenced. Possible interpretations of the long-lasting persistence of the orotate effect are discussed.

  15. Material and Social Incentives to Participation in Behavioral Interventions: A Meta-Analysis of Gender Disparities in Enrollment and Retention in Experimental Human Immunodeficiency Virus Prevention Interventions

    PubMed Central

    Durantini, Marta R.; Albarracín, Dolores

    2013-01-01

    Objective A meta-analysis was conducted to test theoretical hypotheses about the predictors of enrollment and completion of condom-use-promotion interventions among men and women. Design A meta-analysis summarized research reports of the efficacy of experimental interventions on human immunodeficiency virus (HIV) prevention. Main Outcome Measures The outcome measure consisted of (a) a measure of participation, obtained by subtracting the actual number of participants from the number of the invited people, and (b) a measure of retention was obtained by subtracting the number of participants who completed the intervention from the number of commencers. Results Experimental interventions providing instrumental and financial resources (e.g., payments) increased initiation and retention more among predominantly male samples, whereas experimental interventions using group formats increased initiation and retention more among predominantly female samples. These patterns remained while controlling for past condom use, other HIV-risk behaviors, and demographics associated with gender composition. Conclusion People seek out HIV-prevention interventions to fulfill gender-specific needs, and these differences must be taken into account in the design of HIV-prevention interventions. PMID:19751090

  16. Inductively coupled plasma mass spectrometry study of the retention behavior of arsenic species on various solid phase extraction cartridges and its application in arsenic speciation

    NASA Astrophysics Data System (ADS)

    Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang; Khoo, Soo Beng

    2003-07-01

    Inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the retention behavior of arsenite, arsenate, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), arsenocholine (AsC), trimethylarsine oxide (TMAO) and tetramethylarsonium ion (TMAI) on various silica-based solid phase extraction (SPE) cartridges. A method for arsenic speciation is then developed on the basis of selective SPE separation of arsenic species and highly sensitive ICP-MS detection. Factors affecting the retention and elution of arsenic species were examined. Results showed that the retention of arsenic species depended on the chemical characteristics of arsenic species and the types of sorbent materials. Change of pH in the range of 2.0-9.0 did not show significant effects on the retention of DMA, AsB, AsC, TMAI and TMAO on an ethylbenzene sulfonic acid-based strong cation exchange (SCX-3) cartridge. pH also did not influence the retention of AsB, AsC, TMAI and TMAO on a mixed-mode (M-M) cartridge containing non-polar, strong cation exchange and strong anion exchange (SAX) functional groups. However, the retentions of As(V) and MMA on the SAX and the M-M cartridge changed with pH. As(V) and MMA were completely retained on the SAX cartridge and sequentially selectively eluted with 1.0 mol l -1 acetic acid (for MMA). DMA, AsB, AsC, TMAI and TMAO were completely retained on the SCX-3 cartridge and sequentially selectively eluted with 1.0 mol l -1 HNO 3 (for DMA). As(V), MMA, AsB, AsC, TMAI and TMAO were completely retained on the M-M cartridge. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently determined by ICP-MS. A detection limit of 8 ng l -1 arsenic in water sample was obtained. This method was successfully applied to arsenic speciation in various sources of water samples (drinking water, waste water, raw water, etc.) and US National Institute of

  17. Study of thermal behavior of vitamin D3 by pyrolysis-GC-MS in combination with boiling point-retention time correlation.

    PubMed

    Sun, Yu'an; Liu, Baoxia; Wang, Guoqing; Zhang, Rongjie; Xie, Bing

    2005-01-01

    The thermal behavior of vitamin D3 was studied based on pyrolysis-GC-MS technique. It was pyrolyzed at 600 degrees C, 750 degrees C, 900 degrees C, respectively. The pyrolysis product were separated With an HP-5 column and identified by the NIST mass spectral search program in combination with the correlation of boiling point and retention time (BP-RT). There are totally 50 components, including mono aromatics and polycyclic aromatic hydrocarbons (PAHs), were determined. It is shown that the contents of the PAHs are increasing with the increasing of the pyrolysis temperature. The contents of the determined components vary from 0.04% to 37.08%.

  18. Lipophilicity indices derived from the liquid chromatographic behavior observed under bimodal retention conditions (reversed phase/hydrophilic interaction): application to a representative set of pyridinium oximes.

    PubMed

    Voicu, Victor; Sârbu, Costel; Tache, Florentin; Micăle, Florina; Rădulescu, Ştefan Flavian; Sakurada, Koichi; Ohta, Hikoto; Medvedovici, Andrei

    2014-05-01

    The liquid chromatographic behavior observed under bimodal retention conditions (reversed phase and hydrophilic interaction) offers a new basis for the determination of some derived lipophilicity indices. The experiments were carried out on a representative group (30 compounds) of pyridinium oximes, therapeutically tested in acetylcholinesterase reactivation, covering a large range of lipophilic character. The chromatographic behavior was observed on a mixed mode acting stationary phase, resulting from covalent functionalization of high purity spherical silica with long chain alkyl groups terminated by a polar environment created through the vicinal diol substitution at the lasting carbon atoms (Acclaim Mixed Mode HILIC 1 column). Elution was achieved by combining different proportions of 5 mM ammonium formiate solutions in water and acetonitrile. The derived lipophilicity indices were compared with logP values resulting from different computational algorithms. The correlations between experimental and computed data sets are significant. To obtain a better insight on the transition from reversed phase to hydrophilic interaction retention mechanisms, the variation of the thermodynamic parameters determined through the van׳t Hoff approach was also discussed.

  19. Promoting Retention

    PubMed Central

    Hall, LaToya N.; Ficker, Lisa J.; Chadiha, Letha A.; Green, Carmen R.; Jackson, James S.; Lichtenberg, Peter A.

    2016-01-01

    Objectives: The objectives of this study were to evaluate the capability of a research volunteer registry to retain community-dwelling African American older adults, and to explore demographic and health factors associated with retention. Method: A logistic regression model was used to determine the influence of demographics, health factors, and registry logic model activities on retention in a sample of 1,730 older African American adults. Results: Almost 80% of participants active in the volunteer research registry between January 2012 and June 2015 were retained. Employment, being referred to research studies, a higher number of medical conditions, and more follow-up contacts were associated with an increased likelihood of retention. Older age, more months in the registry, and more mobility problems decreased the likelihood of retention. Discussion: These results suggest the Michigan Center for Urban African American Aging Research logic model promotes retention through involving older African American adults in research through study referrals and intensive follow-up. The loss of participants due to age- and mobility-related issues indicate the registry may be losing its most vulnerable participants. PMID:28138501

  20. American Recovery and Reinvestment Act of 2009. Interim Report on Customer Acceptance, Retention, and Response to Time-Based Rates from the Consumer Behavior Studies

    SciTech Connect

    Cappers, Peter; Hans, Liesel; Scheer, Richard

    2015-06-01

    Time-based rate programs1, enabled by utility investments in advanced metering infrastructure (AMI), are increasingly being considered by utilities as tools to reduce peak demand and enable customers to better manage consumption and costs. There are several customer systems that are relatively new to the marketplace and have the potential for improving the effectiveness of these programs, including in-home displays (IHDs), programmable communicating thermostats (PCTs), and web portals. Policy and decision makers are interested in more information about customer acceptance, retention, and response before moving forward with expanded deployments of AMI-enabled new rates and technologies. Under the Smart Grid Investment Grant Program (SGIG), the U.S. Department of Energy (DOE) partnered with several utilities to conduct consumer behavior studies (CBS). The goals involved applying randomized and controlled experimental designs for estimating customer responses more precisely and credibly to advance understanding of time-based rates and customer systems, and provide new information for improving program designs, implementation strategies, and evaluations. The intent was to produce more robust and credible analysis of impacts, costs, benefits, and lessons learned and assist utility and regulatory decision makers in evaluating investment opportunities involving time-based rates. To help achieve these goals, DOE developed technical guidelines to help the CBS utilities estimate customer acceptance, retention, and response more precisely.

  1. The effects of forced-egg retention on the blood-feeding behavior and reproductive potential of Culex pipiens (Diptera: Culicidae).

    PubMed

    Johnson, Brian J; Fonseca, Dina M

    2014-07-01

    High rates of West Nile virus (WNV) transmission to humans are associated with exceptionally hot and dry summers. This is paradoxical since the eggs of Culex vectors of WNV depend on the persistence of containers with water, which decline during droughts. We examined the effects of forced-egg retention on the reproductive success of female Culex pipiens as well as behavioral responses, such as likelihood of secondary blood meals. As controls we examined the effects of female age and delayed mating. We found that early mating is essential to achieve reproductive success and, consistent with an "all-or-none" ovipositing strategy, C. pipiens females are able to retain considerable reproductive potential while searching for oviposition sites. Specifically, although forced-egg retention resulted in significant decreases in fitness, the decline was moderate for 5 weeks and most can be accounted for by increases in female age. Consequently, no females took blood more than once per gonotrophic cycle, which eliminates the possibility that heightened vectorial capacity due to multiple blood-feedings increases WNV transmission during periods of drought. Instead, our findings suggest that during droughts populations of C. pipiens have time to locate the remaining water holes, which are associated with human populations and WNV-competent bird species.

  2. Effects of ionic strength on bacteriophage MS2 behavior and their implications for the assessment of virus retention by ultrafiltration membranes.

    PubMed

    Furiga, Aurelie; Pierre, Gwenaelle; Glories, Marie; Aimar, Pierre; Roques, Christine; Causserand, Christel; Berge, Mathieu

    2011-01-01

    Bacteriophage MS2 is widely used as a surrogate to estimate pathogenic virus elimination by membrane filtration processes used in water treatment. Given that this water technology may be conducted with different types of waters, we focused on investigating the effects of ionic strength on MS2 behavior. For this, MS2 was analyzed while suspended in solutions of various ionic strengths, first in a batch experiment and second during membrane ultrafiltration, and quantified using (i) quantitative reverse transcriptase PCR (qRT-PCR), which detects the total number of viral genomes, (ii) qRT-PCR without the RNA extraction step, which reflects only particles with a broken capsid (free RNA), and (iii) the PFU method, which detects only infectious viruses. At the beginning of the batch experiments using solutions containing small amounts of salts, losses of MS2 infectivity (90%) and broken particles (20%) were observed; these proportions did not change during filtration. In contrast, in high-ionic-strength solutions, bacteriophage kept its biological activity under static conditions, but it quickly lost its infectivity during the filtration process. Increasing the ionic strength decreased both the inactivation and the capsid breakup in the feed suspension and increased the loss of infectivity in the filtration retentate, while the numbers of MS2 genomes were identical in both experiments. In conclusion, the effects of ionic strength on MS2 behavior may significantly distort the results of membrane filtration processes, and therefore, the combination of classical and molecular methods used here is useful for an effective validation of the retention efficiency of ultrafiltration membranes.

  3. Urinary Retention

    MedlinePlus

    ... indicates the bladder does not empty completely. A health care provider performs this test during an office visit. The patient often receives ... more urodynamic tests to diagnose urinary retention. The health care provider will perform these tests during an office visit. For tests that use ...

  4. Retention Checklist.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    Designed to improve student retention at Bronx Community College (BCC), this workbook is comprised of sets checklists for use by students in evaluating their progress toward a number of academic, personal, and work-related goals. The workbook is divided into five sections, each containing a set of goals and associated checklists. Part I deals with…

  5. Occurrence of pharmaceuticals and endocrine disruptors in raw sewage and their behavior in UASB reactors operated at different hydraulic retention times.

    PubMed

    Queiroz, F B; Brandt, E M F; Aquino, S F; Chernicharo, C A L; Afonso, R J C F

    2012-01-01

    This work investigated the occurrence of pharmaceuticals and endocrine disrupting compounds (EDCs) in raw sewage (from Belo Horizonte city, Minas Gerais state, Brazil) and assessed their behavior in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) operated at different hydraulic retention times (HRT). The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The natural (estradiol) and synthetic (ethinylestradiol) estrogens were hardly detected; when present, however, their concentrations were lower than the method quantification limits. The concentrations of bisphenol A and miconazole in raw sewage were similar to that reported in the literature (around 200 ng L⁻¹ and hardly detected, respectively). The antibiotics sulfamethoxazole (median 13.0 ng L⁻¹) and trimethoprim (median 61.5 ng L⁻¹), and the other pharmaceutical compounds (diclofenac and bezafibrate, with median 99.9 and 94.4 ng L⁻¹, respectively) were found in lower concentrations when compared with reports in the literature, which might indicate a lower consumption of such drugs in Brazil. The UASB reactors were inefficient in the removal of bisphenol A, and led to an increased concentration of nonylphenol in the effluent. The anaerobic reactors were also inefficient in the removal of diclofenac, and led to a partial removal of bezafibrate; whereas, for sulfamethoxazole there seemed to be a direct relationship between the HRT and removal efficiencies. For trimethoprim the sludge retention time (SRT) seemed to play an important role, although it was only partially removed in the UASB reactors.

  6. [Influences of ion-suppressors on retention behaviors of nine food additives in reversed-phase high performance liquid chromatographic separation].

    PubMed

    Zhao, Yonggang; Chen, Xiaohong; Li, Xiaoping; Yao, Shanshan; Jin, Micong

    2011-10-01

    The influences of ion-suppressors on retention behaviors of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in reversed-phase high performance liquid chromatographic (RP-HPLC) separation were investigated. The organic modification effects of acids, i. e. , trifluoroacetic acid (TFA) and buffer salts, i. e. , TFA-ammonium acetate (AmAc) were studied emphatically. The relationships between retention factors of solutes and volume percentages of ion-suppressors in the mobile phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, separately. The separation of nine food additives was completed by a gradient elution with acetonitrile-TFA (0.01%, v/v)-AmAc (2. 5 mmol/L) aqueous solution as the mobile phases. An RP-HPLC method was established for the simultaneous determination of nine food additives in red wine. In the range of 10. 0 - 100. 0 mg/L, nine food additives showed good linearity with the correlation coefficients ( r2 ) larger than 0. 999 1. The limits of detection (LODs) were in the range of 0. 33 - 2. 36 mg/L and the limits of quantification (LOQs) were in the range of 1. 11 - 7. 80 mg/L. The spiked recoveries were between 87. 61% and 108. 4% with the relative standard deviations (RSDs) of 2. 2% -9. 4%. These results are of referential significance for the rapid establishment and accu- rate optimization of RP-HPLC separation for the simultaneous determination of food additives in other foods.

  7. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2004-03-31

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2003 to March 31, 2004 which covers the third six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, temperature scans were performed mixing equal volumes of ethylbenzene and 10mM NaCl water with various concentrations of ethanol ranging from 2 to 70 vol%. For the range of temperatures tested (2 to 70 C), results indicate that temperature is invariant and produced a single phase for ethanol concentrations greater than 60 vol%. For ethanol concentrations less than 60 vol%, only two phases were obtained with aqueous rich bottom phase more in volume than that of the ethylbenzene rich top phase. Linear coreflooding experiments were completed by our industrial partner in this project, Surtek, CO, to measure the condensate recovery in flooding processes. It was found about 30% ethylbenzene recovery was obtained by the waterflooding, however, 2wt% ethanol flooding did not produce incremental recovery of the ethylbenzene. Radial coreflooding with ethanol injection prior to water injection is in progress to assess the effectiveness of the surfactant flooding in the recovery of condensate.

  8. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2003-03-31

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2002 to April 01, 2003 which covers the first six months of the project. Presently work is in progress to characterize phase and emulsion behavior for condensate/water/ethanol system. Temperature and salinity scans are planned to identify the optimal salinity and temperature, and the temperature and salinity intervals in which all three phases coexist for this system. Test matrix to perform salinity and temperature scans has been established. Supply requests to obtain hydrocarbons, surfactant, etc., were processed and supplies obtained. Current literature in the subject area, and modeling efforts that were established in our previous studies to predict electrical conductivities and inversion phenomena were reviewed. Based on the review a computer model to predict electrical conductivities of the ethylbenzene (that has the equivalent carbon number of the condensate)/water/ethanol system is being developed. These activities resulted in one published conference abstract during this reporting period.

  9. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2005-03-31

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2004 to March 31, 2005 which covers the fifth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, electrical conductivity measurements for bottom, and top phases, as well as bottom/top, and top/bottom conjugate pair phases of the ethylbenzene/water/ethanol system were performed for various ethanol volume percentage of the mixtures starting from 2% to 60%. Preliminary findings are that electrical conductivity of the bottom phase decreased as ethanol volume fraction of the mixture increased. Conductivity of the top phase was small and remained almost the same for variations in ethanol volume fraction of the mixture. Conductivity of the emulsion of the conjugate pair phases decreased as the fraction of volume of the top phase was increased and vice versa. Also inversion phenomena was observed. Detailed analyses are in progress including the prediction of conductivity data using the theoretical model already developed in this project.

  10. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2005-09-30

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period April 01, 2005 to September 30, 2005 which covers the sixth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. In the last reporting period, electrical conductivity measurements for bottom/top, and top/bottom conjugate pair phases of the ethylbenzene/water/ethanol system were performed for various ethanol volume percentage in the mixture: 2,10,20,33,43,50, and 56. During this reporting period, prediction of electrical conductivity data obtained in the past was conducted employing a theoretical model already developed in this project. Results of the comparisons for 2, and 10% ethanol volume in the mixture are presented here. A good agreement was obtained between the predicted emulsion conductivities and the measured values. To date about 99% of the proposed work has been completed. Conductivity prediction for 56% ethanol volume in the mixture is in progress. Following this prediction, a final report will be developed describing the research activities conducted through the entire project period including results and conclusions.

  11. Development of comprehensive descriptors for multiple linear regression and artificial neural network modeling of retention behaviors of a variety of compounds on different stationary phases.

    PubMed

    Jalali-Heravi, M; Parastar, F

    2000-12-01

    A new series of six comprehensive descriptors that represent different features of the gas-liquid partition coefficient, K(L), for commonly used stationary phases is developed. These descriptors can be considered as counterparts of the parameters in the Abraham solvatochromic model of solution. A separate multiple linear regression (MLR) model was developed by using the six descriptors for each stationary phase of poly(ethylene glycol adipate) (EGAD), N,N,N',N'-tetrakis(2-hydroxypropyl) ethylenediamine (THPED), poly(ethylene glycol) (Ucon 50 HB 660) (U50HB), di(2-ethylhexyl)phosphoric acid (DEHPA) and tetra-n-butylammonium N,N-(bis-2-hydroxylethyl)-2-aminoethanesulfonate (QBES). The results obtained using these models are in good agreement with the experiment and with the results of the empirical model based on the solvatochromic theory. A 6-6-5 neural network was developed using the descriptors appearing in the MLR models as inputs. Comparison of the mean square errors (MSEs) shows the superiority of the artificial neural network (ANN) over that of the MLR. This indicates that the retention behavior of the molecules on different columns show some nonlinear characteristics. The experimental solvatochromic parameters proposed by Abraham can be replaced by the calculated descriptors in this work.

  12. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2004-09-30

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period April 01, 2004 to September 30, 2004 which covers the fourth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, work was under way and the electrical conductivity experimental system was set up at the Atlanta University Center. Following the set-up of the emulsion measurement system, the electronic instruments and data acquisition modules involved were tested for proper operation of the system. Then, the conductivity output was normalized with that obtained for 10mM NaCl water. Radial coreflooding experiments with ethanol injection prior to and after water injection were completed to assess the effectiveness of the surfactant flooding in the recovery of condensate by our industrial partner, Surtek, CO, in this reporting period. In Run 1, 10 mM NaCl without ethanol injection recovered 31.5% of the initial ethyl benzene saturation. Injection of ethanol following 10 mM NaCl produced a tertiary ethyl benzene bank with maximum ethyl benzene cuts of 32%. In Run 2, 50 vol% of pure (100%) ethanol was injected and flowed through the Berea sandstone after Ethyl Benzene Saturation. 69% of the initial ethyl benzene was recovered. Results of the radial corefloods are very encouraging. Emulsion conductivity measurements for conjugate pair phases are in progress at Morehouse.

  13. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transport, retention, and long-term fate of zinc oxide nanoparticles (ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and t...

  14. Investigation of the retention behavior of structurally diverse drugs on alpha(1) acid glycoprotein column: insight on the molecular factors involved and correlation with protein binding data.

    PubMed

    Chrysanthakopoulos, Marios; Vallianatou, Theodosia; Giaginis, Costas; Tsantili-Kakoulidou, Anna

    2014-08-18

    Retention of 49 structurally diverse drugs on alpha1 acid glycoprotein column was investigated under different chromatographic conditions. Acetonitrile and 2-propanol were used as organic modifiers at different percentages and the pH was adjusted at 7.0 using PBS. Analysis of extrapolated and isocratic retention in terms of lipophilicity and electrostatic interactions revealed significant effect of the nature and percentage of organic modifier, which was attributed to the different shielding degree of the charged sites on the stationary phase by the buffer constituents. AGP retention factors were compared to HSA retention factors analyzed previously. Application of LSER analysis, extended to incorporate fractions ionized, demonstrated hydrogen bond acidity, dipolarity/polarizability and excess molar refraction as the most significant parameters for all AGP chromatographic indices, elucidating the differentiation of AGP retention from octanol-water partitioning and HSA retention. An attempt to correlate AGP chromatographic indices to AGP association constants, available in literature, supported the importance of stationary shielding in retention mechanism. Thus, isocratic retention factors logk10(ACN)(AGP) show a moderate but still better performance than lipophilicity in the case of A variant and may be a useful tool for the estimation of relevant association constants. For F1/S binding simulation lower stationary phase shielding is needed to obtain a significant two term regression equation, where logk20(ACN)(AGP) exerts a secondary contribution next to the most important bulk effect expressed by molecular weight.

  15. Pulmonary retention of coal dusts

    SciTech Connect

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  16. INVESTIGATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND CONDENSATE RECOVERY FOR CONDENSATE/WATER/ETHANOL MIXTURES

    SciTech Connect

    Ramanathan Sampath

    2005-12-01

    This final technical report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2002 to September 30, 2005, which covers the total performance period of the project. During this period, work was conducted to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number was used as the model condensate. Salinity scans were performed for 0, 5, 10, 20, 50, 100, 250, 500, and 1000 mM salt concentrations at room temperature to identify the optimal salinity and salinity intervals in which all phases coexisted. It was found that only two phases formed, and salinity has no significant effect in the volumes of the phases formed. Experiments were repeated at 30 C and observed salinity has no effect at higher temperatures as well. Following the salinity experiments, measurements were made with 10mM NaCl water for surfactant concentrations from 2 to 70 volume percent at room temperature. It was found that only two phases were formed upto 60 vol% concentration of the surfactant. Above 60 vol% surfactant, the mixture produced only a single phase. Experiments were repeated from 2 to 70 C and observed that temperature has no significant effect on the number of phases formed. At the temperatures and surfactant concentration tested, volume fraction of the aqueous bottom phase was found to be larger than that of the top phase. Electrical conductivity measurements were then conducted for bottom/top, and top/bottom conjugate pair phases of the ethylbenzene/water/ethanol system formed by mixing ethanol at various volume percentages including 2,10,33,and 56% while keeping the volumes of ethylbenzene and water the same in the mixture. Electrical conductivity of the bottom phase decreased as ethanol volume fraction in the mixture increased. Conductivity of the top phase was found small and remained almost the same for variations in ethanol volume fraction in

  17. Managing retention.

    PubMed

    Carter, Tony

    2007-01-01

    To build this process it is necessary to consult customers for preferences, build familiarity and knowledge to build a relationship and conduct business in a customized fashion. The process takes every opportunity to build customer satisfaction with each customer contact. It is an important process to have, since customers today are more demanding, sophisticated, educated and comfortable speaking to the company as an equal (Belk, 2003). Customers have more customized expectations so they want to be reached as individuals (Raymond and Tanner, 1994). Also, a disproportionate search for new business is costly. The cost to cultivate new customers is more than maintaining existing customers (Cathcart, 1990). Other reasons that customer retention is necessary is because many unhappy customers will never buy again from a company that dissatisfied them and they will communicate their displeasure to other people. These dissatisfied customers may not even convey their displeasure but without saying anything just stop doing business with that company, which may keep them unaware for some time that there is any problem (Cathcart, 1990).

  18. Classroom Management for Student Retention.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    This guidebook recommends methods for teachers to use to improve teacher-student interaction in the classroom, as a means of increasing student retention. Chapter I introduces eight major systems of classroom management which teachers may use as their values and the classroom situation dictate: "Behavior Modification,""Reality Therapy,""Discipline…

  19. Strategies for Teacher Retention.

    ERIC Educational Resources Information Center

    Gonzalez, Patricia

    1995-01-01

    Strategies for teacher retention are presented, including successful approaches and elements for operating a state system for personnel recruitment and retention in special education. Such initiatives as the Utah Mentor Teacher Academy; the Texas Teacher Recruitment, Retention and Assistance Program; and the Kansas Recruitment/Retention Project…

  20. Retentivity, selectivity and thermodynamic behavior of polycyclic aromatic hydrocarbons on charge-transfer and hypercrosslinked stationary phases under conditions of normal phase high performance liquid chromatography.

    PubMed

    Jiang, Ping; Lucy, Charles A

    2016-03-11

    Charge-transfer and hypercrosslinked polystyrene phases offer retention and separation for polycyclic aromatic hydrocarbons (PAHs) and thus have potential for petroleum analysis. The size, shape and planarity selectivity for PAH standards on charge-transfer (DNAP column) and hypercrosslinked polystyrene (HC-Tol and 5HGN columns) phases are different under normal phase liquid chromatography (NPLC). The HC-Tol column behaves like a conventional NPLC column with low retention of PAHs. Retention of PAHs on the DNAP and 5HGN are strong and increases with the number of aromatic rings. The main retention mechanism is through π-π interactions and dipole-induced dipole interaction. Thermodynamics indicates that the retention mechanism of PAHs remains unchanged over the temperature range 20-60°C. In addition, on either DNAP or 5HGN column, both linear and bent PAHs are retained through the same mechanism. But DNAP possesses smaller π-π interaction and higher planarity selectivity than 5HGN for PAHs. This is suggestive that DNAP interacts with PAHs through a disordered phase arrangement, while 5HGN behaves as an ordered adsorption phase.

  1. Effect of chromatographic conditions on retention behavior and system efficiency for HPTLC of selected psychotropic drugs on chemically bonded stationary phases.

    PubMed

    Petruczynik, Anna; Wróblewski, Karol; Waksmundzka-Hajnos, Monika

    2015-01-01

    Selected psychotropic drug standards have been chromatographed on RP18, CN and diol layers with a variety of aqueous and nonaqueous mobile phases. The effect of buffers at acidic or basic pH, acetic acid, ammonia and diethylamine (DEA) in aqueous mobile phases on retention, efficiency and peak symmetry was examined. Improved peak symmetry and separation selectivity for investigated compounds were observed when ammonia or DEA were used as mobile phase additives. The effect of diethylamine concentration in aqueous eluents on retention, peak symmetry and theoretical plate number obtained on CN plates was also investigated. Because of the strong retention of these basic drugs on stationary phases bonded on silica matrix, nonaqueous eluents containing medium polar diluents, strongly polar modifiers and silanol blockers (ammonia or diethylamine) were applied. Aqueous and nonaqueous eluent systems with the best selectivity and efficiency were used for separate psychotropic drug standards' mixture on CN layer by 2D TLC.

  2. Towards a Dynamic DES model

    NASA Astrophysics Data System (ADS)

    Subbareddy, Pramod; Candler, Graham

    2009-11-01

    Hybrid RANS/LES methods are being increasingly used for turbulent flow simulations in complex geometries. Spalart's detached eddy simulation (DES) model is one of the more popular ones. We are interested in examining the behavior of the Spalart-Allmaras (S-A) Detached Eddy Simulation (DES) model in its ``LES mode.'' The role of the near-wall functions present in the equations is analyzed and an explicit analogy between the S-A and a one-equation LES model based on the sub-grid kinetic energy is presented. A dynamic version of the S-A DES model is proposed based on this connection. Validation studies and results from DES and LES applications will be presented and the effect of the proposed modification will be discussed.

  3. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating.

    PubMed

    Han, Yosep; Hwang, Gukhwa; Kim, Donghyun; Bradford, Scott A; Lee, Byoungcheun; Eom, Igchun; Kim, Pil Je; Choi, Siyoung Q; Kim, Hyunjung

    2016-03-01

    The transport, retention, and long-term release of zinc oxide nanoparticle aggregates (denoted below as ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and the ionic strength (IS) was 0.1 or 10 mM NaCl, and the retention profiles were always hyper-exponential. Increasing the solution IS and biofilm coating produced enhanced retention of ZnO-NPs near the column inlet. The enhanced NPs retention at high IS was attributed to more favorable NP-silica and NP-NP interactions; this was consistent with the interaction energy calculations. Meanwhile, the greater NPs retention in the presence of biofilm was attributed to larger roughness heights which alter the mass transfer rate, the interaction energy profile, and lever arms associated with the torque balance; e.g., scanning electron and atomic force microscopy was used to determine roughness heights of 33.4 nm and 97.8 nm for bare sand and biofilm-coated sand, respectively. Interactions between NPs and extracellular polymeric substances may have also contributed to enhanced NP retention in biofilm-coated sand at low IS. The long-term release of retained ZnO-NPs was subsequently investigated by continuously injecting NP-free solution at pH 6, 9, or 10 and keeping the IS constant at 10 mM. The amount and rate of retained ZnO-NP removal was strongly dependent on the solution pH. Specifically, almost complete removal of retained ZnO-NPs was observed after 627 pore volumes when the solution pH was 6, whereas much less Zn was recovered when the eluting solution pH was buffered to pH = 9 and especially 10. This long-term removal was attributed to pH-dependent dissolution of retained ZnO-NPs because: (i) the solubility of ZnO-NPs increases with decreasing pH; and (ii) ZnO-NPs were not detected in the effluent. The presence of biofilm also decreased the

  4. Fuel nozzle tube retention

    DOEpatents

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  5. Des Moines.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This document, intended for elementary students, contains articles and activities designed to acquaint young people with the history of Des Moines, Iowa. The articles are short, and new or difficult words are highlighted and defined for young readers. "The Raccoon River Indian Agency" discusses the archeological exploration of the indian…

  6. Difference equation model for isothermal gas chromatography expresses retention behavior of homologues of n-alkanes excluding the influence of holdup time.

    PubMed

    Wu, Liejun; Chen, Yongli; Caccamise, Sarah A L; Li, Qing X

    2012-10-19

    A difference equation (DE) model is developed using the methylene retention increment (Δtz) of n-alkanes to avoid the influence of gas holdup time (tM). The effects of the equation orders (1st-5th) on the accuracy of a curve fitting show that a linear equation (LE) is less satisfactory and it is not necessary to use a complicated cubic or higher order equation. The relationship between the logarithm of Δtz and the carbon number (z) of the n-alkanes under isothermal conditions closely follows the quadratic equation for C3-C30n-alkanes at column temperatures of 24-260 °C. The first and second order forward differences of the expression (Δlog Δtz and Δ2log Δtz, respectively) are linear and constant, respectively, which validates the DE model. This DE model lays a necessary foundation for further developing a retention model to accurately describe the relationship between the adjusted retention time and z of n-alkanes.

  7. EFFECTS OF TELENCEPHALIC RADIOLESIONS ON LEARNING AND RETENTION IN THE PIGEON (COLUMBA LIVIA). APPENDIX II.

    DTIC Science & Technology

    PIGEONS, BEHAVIOR), (*BEHAVIOR, RADIATION EFFECTS), (*RADIATION EFFECTS, CENTRAL NERVOUS SYSTEM), (*LEARNING, RADIATION EFFECTS), RETENTION(PSYCHOLOGY), RADIATION INJURIES, BRAIN , NERVOUS SYSTEM, PHYSIOLOGY, RESPONSE, SWEDEN

  8. Clay particle retention in small constructed wetlands.

    PubMed

    Braskerud, B C

    2003-09-01

    Constructed wetlands (CWs) can be used to mitigate non-point source pollution from arable fields. Previous investigations have shown that the relative soil particle retention in small CWs increases when hydraulic load increases. This paper investigates why this phenomenon occurs, even though common retention models predict the opposite, by studying clay and silt particle retention in two Norwegian CWs. Retention was measured with water flow proportional sampling systems in the inlet and outlet of the wetlands, and the texture of the suspended solids was analyzed. The surface area of the CWs was small compared to the watershed area (approximately 0.07%), giving high average hydraulic loads (1.1 and 2.0 md(-1)). One of the watersheds included only old arable land, whereas the other included areas with disturbed topsoil after artificial land leveling. Clay particle retention was 57% for the CW in the first watershed, and 22% for the CW in the disturbed watershed. The different behavior of the wetlands could be due to differences in aggregate size and stability of the particles entering the wetlands. Results showed that increased hydraulic loads did affect CW retention negatively. However, as runoff increased, soil particles/aggregates with higher sedimentation velocities entered the CWs (e.g., the clay particles behaved as silt particles). Hence, clay particle settling velocity is not constant as assumed in many prediction models. The net result was increased retention.

  9. Retention, retention, retention: targeting the young in CPR skills training!

    PubMed

    Roppolo, Lynn P; Pepe, Paul E

    2009-01-01

    The usefulness of basic cardiopulmonary resuscitation (CPR) training in school systems has been questioned, considering that young students may not have the physical or cognitive skills required to perform complex tasks correctly. In the study conducted by Fleishhackl and coworkers, students as young as 9 years were able to successfully and effectively learn basic CPR skills, including automated external defibrillator deployment, correct recovery position, and emergency calling. As in adults, physical strength may limit the depth of chest compressions and ventilation volumes given by younger individuals with low body mass index; however, skill retention is good. Training all persons across an entire community in CPR may have a logarithmic improvement in survival rates for out-of-hospital cardiac arrest because bystanders, usually family members, are more likely to know CPR and can perform it immediately, when it is physiologically most effective. Training captured audiences of trainees, such as the entire work-force of the community or the local school system, are excellent mechanisms to help achieve that goal. In addition to better retention with new half hour training kits, a multiplier effect can be achieved through school children. In addition, early training not only sets the stage for subsequent training and better retention, but it also reinforces the concept of a social obligation to help others.

  10. The Effect of Voice Ambulatory Biofeedback on the Daily Performance and Retention of a Modified Vocal Motor Behavior in Participants with Normal Voices

    ERIC Educational Resources Information Center

    Van Stan, Jarrad H.; Mehta, Daryush D.; Hillman, Robert E.

    2015-01-01

    Purpose: Ambulatory biofeedback has potential to improve carryover of newly established vocal motor behaviors into daily life outside of the clinic and warrants systematic research that is lacking in the literature. This proof-of-concept study was designed to establish an empirical basis for future work in this area by formally assessing whether…

  11. Effects of Episodic Variations in Web-Based Avian Influenza Education: Influence of Fear and Humor on Perception, Comprehension, Retention and Behavior

    ERIC Educational Resources Information Center

    Kim, Paul; Sorcar, Piya; Um, Sujung; Chung, Heedoo; Lee, Young Sung

    2009-01-01

    In order to provide empirical evidence on the role of a web-based avian influenza (AI) education program for mass communication and also ultimately help young children learn and develop healthy behaviors against AI and all types of influenza, an education program with two episodic variations (i.e. fear and humor) has been developed and examined…

  12. Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat Part 2: Effects on reproductive parameters, on sex behavior, on memory retention and on hypothalamic expression of aromatase and 5alpha-reductases in the offspring.

    PubMed

    Colciago, A; Casati, L; Mornati, O; Vergoni, A V; Santagostino, A; Celotti, F; Negri-Cesi, P

    2009-08-15

    The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted mixture of four indicator congeners (PCB 126, 138, 153 and 180) was injected subcutaneously to dams at the dose of 10 mg/kg daily from GD15 to GD19 and then twice a week till weanling. The results indicated that developmental PCB exposure produced important changes in the dimorphic hypothalamic expression of both aromatase and the 5alpha-Rs, which were still evident in adult animals. We observed that female puberty onset occurs earlier than in control animals without cycle irregularity, while testicular descent in males was delayed. A slight but significant impairment of sexual behavior and an important alteration in memory retention were also noted specifically in males. We conclude that PCBs might affect the dimorphic neuroendocrine control of reproductive system and of other neurobiological processes.

  13. Teacher Beliefs regarding Grade Retention in an Urban Elementary School

    ERIC Educational Resources Information Center

    Gilmore-Hook, Toni

    2011-01-01

    The purpose of this study was to determine if exposure to a research-based presentation on grade retention, including the academic, socio-emotional and behavioral outcomes, would yield a change in teacher beliefs regarding retention as an intervention strategy. Teachers from a small urban school district were asked to complete a pre-survey, view a…

  14. Development of Theories of Collective and Cognitive Skill Retention

    DTIC Science & Technology

    2016-06-07

    Skill Retention Humansystems® Incorporated ® 5.2.1 Structure of the collective While consideration of organizational psychology was deemed beyond...consulted to collect available data for review. Review of the selected material revealed five factors: task variables, structure of the collective...variables des tâches, la structure du collectif, les membres du collectif, les différences individuelles et la formation. On n’a relevé qu’un

  15. Alternatives to Social Promotion and Retention

    ERIC Educational Resources Information Center

    Lynch, Matthew

    2013-01-01

    Studies indicate that retention negatively impacts students' behavior, attitude, and attendance, but it is still practiced in schools around the country. Social promotion undermines students' futures when they fail to develop critical study and job-related skills; however, it too is still practiced in many schools throughout the United…

  16. Drug Retention Times

    SciTech Connect

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  17. Effects of 3 Hz and 60 Hz Extremely Low Frequency Electromagnetic Fields on Anxiety-Like Behaviors, Memory Retention of Passive Avoidance and Electrophysiological Properties of Male Rats

    PubMed Central

    Rostami, Amin; Shahani, Minoo; Zarrindast, Mohammad Reza; Semnanian, Saeed; Rahmati Roudsari, Mohammad; Rezaei Tavirani, Mostafa; Hasanzadeh, Hadi

    2016-01-01

    Introduction: The effects of electromagnetic fields on biological organisms have been a controversial and also interesting debate over the past few decades, despite the wide range of investigations, many aspects of extremely low frequency electromagnetic fields (ELF/EMFs) effects including mechanism of their interaction with live organisms and also their possible biological applications still remain ambiguous. In the present study, we investigated whether the exposures of ELF/EMF with frequencies of 3 Hz and 60 Hz can affect the memory, anxiety like behaviors, electrophysiological properties and brain’s proteome in rats. Methods: Male rats were exposed to 3 Hz and 60 Hz ELF/EMFs in a protocol consisting of 2 cycles of 2 h/day exposure for 4 days separated with a 2-day interval. Short term memory and anxiety like behaviors were assessed immediately, 1 and 2 weeks after the exposures. Effects of short term exposure were also assessed using electrophysiological approach immediately after 2 hours exposure. Results: Behavioral test revealed that immediately after the end of exposures, locomotor activity of both 3 Hz and 60 Hz exposed groups significantly decreased compared to sham group. This exposure protocol had no effect on anxiety like behavior during the 2 weeks after the treatment and also on short term memory. A significant reduction in firing rate of locus coeruleus (LC) was found after 2 hours of both 3 Hz and 60 Hz exposures. Proteome analysis also revealed global changes in whole brain proteome after treatment. Conclusion: Here, some evidence regarding the fact that such exposures can alter locomotor activity and neurons firing rate in male rats were presented. PMID:27330708

  18. Mentorship: increasing retention probabilities.

    PubMed

    Leners, Debra Woodard; Wilson, Vicki W; Connor, Peggy; Fenton, Joanne

    2006-11-01

    Retaining nurses is a significant workforce issue. Experienced nurses in particular are getting harder to retain within hospitals and the discipline at large. One solution to boost retention is to give serious attention to professional socialization activities through contemporary nurse mentorship experiences. The authors contend that contemporary mentoring programmes, targeting developmental quality of life issues of the expert nurse, would appreciably benefit retention programmes within the hospital environment.

  19. Foraging behavior of the mangrove sesarmid crab Neosarmatium trispinosum enhances food intake and nutrient retention in a low-quality food environment

    NASA Astrophysics Data System (ADS)

    Harada, Yota; Lee, S. Y.

    2016-06-01

    The large sesarmid crab Neosarmatium trispinosum has been reported to actively collect freshly fallen mangrove leaves and store them in its burrow where they are assumed to age prior to consumption. This leaf-catching behavior was hypothesized to improve the palatability and nutritional quality of leaves through leaching of feeding deterrent and microbial enrichment during storage. Earlier studies also hypothesized that N. trispinosum feeds on sediment or animal material to meet their N needs. A series of experiments was carried out to investigate the foraging behavior of N. trispinosum against these hypotheses. Study of foraging behavior using remotely operated cameras indicated that this crab spends the far majority of time (97.5 ± 2.5%, SD) underground and only a small percentage of time outside its burrow foraging (2.2 ± 2.3%). Collection of fresh mangrove litter was swift but no record of predation was evident over 31 h of video records. A field leaf tethering experiment showed that this crab started to consume the leaves immediately after collection rather than storing whole leaves, refuting the leaf-aging hypothesis. N. trispinosum also showed a preference for senescent yellow leaves over decaying brown leaves. This behavior may only aim to stock leaves (i.e. to ensure food availability) rather than conditioning them through decay (i.e. to improve food quality). Analysis of gut contents showed that vascular plant material was the dominant food item (83.3 ± 4.6%), followed by sediment (9.2 ± 4.6%) but no animal materials were recorded. N. trispinosum therefore relies minimally on animal food but are capable of removing 50% of the daily leaf litter production. Elemental C, N analysis shows that sediment inside the burrow is a sufficient potential food source (C/N = 13 to 15). While having a lower C/N ratio than fresh green or yellow leaves, the N content of sediment (∼0.1%) was significantly lower than those of mangrove leaves (0.3-0.9%), and may thus

  20. Grade Retention and Its Association with School Misconduct in Adolescence: A Multilevel Approach

    ERIC Educational Resources Information Center

    Demanet, Jannick; Van Houtte, Mieke

    2013-01-01

    Few studies with respect to grade retention and school-disruptive behavior have focused on adolescence. Moreover, previous retention research has ignored multilevel issues. This study aims to fill these research lacunae by addressing the role of grade retention in adolescent students' school misconduct. Furthermore, we explore the role of the…

  1. Post-deposition early-phase migration and retention behavior of radiocesium in a litter-mineral soil system in a Japanese deciduous forest affected by the Fukushima nuclear accident.

    PubMed

    Koarashi, Jun; Nishimura, Syusaku; Nakanishi, Takahiro; Atarashi-Andoh, Mariko; Takeuchi, Erina; Muto, Kotomi

    2016-12-01

    The fate of radiocesium ((137)Cs) derived from the Fukushima nuclear accident and associated radiation risks are largely dependent on its migration and retention behavior in the litter-soil system of Japanese forest ecosystems. However, this behavior has not been well quantified. We established field lysimeters in a Japanese deciduous broad-leaved forest soon after the Fukushima nuclear accident to continuously monitor the downward transfer of (137)Cs at three depths: the litter-mineral soil boundary and depths of 5 cm and 10 cm in the mineral soil. Observations were conducted at two sites within the forest from May 2011 to May 2015. Results revealed similar temporal and depth-wise variations in (137)Cs downward fluxes for both sites. The (137)Cs downward fluxes generally decreased year by year at all depths, indicating that (137)Cs was rapidly leached from the forest-floor litter layer and was then immobilized in the upper (0-5 cm) mineral soil layer through its interaction with clay minerals. The (137)Cs fluxes also showed seasonal variation, which was in accordance with variations in the throughfall and soil temperature at the sites. There was no detectable (137)Cs flux at a depth of 10 cm in the mineral soil in the third and fourth years after the accident. The decreased inventory of mobile (or bioavailable) (137)Cs observed during early stages after deposition indicates that the litter-soil system in the Japanese deciduous forest provides only a temporary source for (137)Cs recycling in plants.

  2. Financial Literacy and Retention

    ERIC Educational Resources Information Center

    Adams, Ruth L.

    2006-01-01

    Higher education administrators know it is more cost-effective to keep students than to recruit them. Understanding financial literacy--and how it impacts student retention and persistence on the campuses--is an important concept for administrators to comprehend. Most students are not financially literate when they enter the world of higher…

  3. Tritium retention in TFTR

    SciTech Connect

    Dylla, H.F.; Wilson, K.L.

    1988-04-01

    This report discusses the materials physics related to D-T operation in TFTR. Research activities are described pertaining to basic studies of hydrogenic retention in graphite, hydrogen recycling phenomena, first-wall and limiter conditioning, surface analysis of TFTR first-wall components, and estimates of the tritium inventory.

  4. Secondary Retention Alternative.

    ERIC Educational Resources Information Center

    Baenen, Nancy R.; Hopkins, Patricia

    Two alternatives to retention in grade for secondary school students were evaluated in Austin (Texas). Both were designed to allow students who are potential retainees (PRs) to receive remediation in one semester. The Transitional Academic Program (TAP) allows PRs to enroll in ninth-grade courses while repeating eighth-grade courses they had…

  5. Principals Retention. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2005-01-01

    Many districts are struggling with the problem of administrator retention. Hoffman (2004) identifies some of the reasons for this: (1) Increased accountability expectations; (2) Diminished or static levels of resources to support reform efforts; (3) Greater administrator vulnerability to sanctions; (4) The complex demands of government and the…

  6. Data Show Retention Disparities

    ERIC Educational Resources Information Center

    Adams, Caralee J.; Robelen, Erik W.; Shah, Nirvi

    2012-01-01

    New nationwide data collected by the U.S. Department of Education's civil rights office reveal stark racial and ethnic disparities in student retentions, with black and Hispanic students far more likely than white students to repeat a grade, especially in elementary and middle school. The contrast is especially strong for African-Americans. In the…

  7. Genetics Home Reference: chylomicron retention disease

    MedlinePlus

    ... Retention Disease MalaCards: chylomicron retention disease Merck Manual Consumer Version: Hypolipidemia Merck Manual Consumer Version: Overview of Malabsorption Orphanet: Chylomicron retention disease ...

  8. Mobile Learning and Student Retention

    ERIC Educational Resources Information Center

    Fozdar, Bharat Inder; Kumar, Lalita S.

    2007-01-01

    Student retention in open and distance learning (ODL) is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not…

  9. Psychogenic urinary retention.

    PubMed

    Bird, J R

    1980-01-01

    The literature on psychogenic urinary retention is reviewed. 2 cases treated by analytical psychotherapy are reported, in which significant demand for physical punishment was revealed and seen as linked to unacceptable, unconscious sadistic and aggressive feelings. Some psychodynamic aspects of what is considered to be "a disturbance of internal body space' are discussed. Psychogenic urinary retention has received little attention in the literature. It may represent the uneasy position this disorder of bodily function occupies in clinical practice, with clear physical symptoms and associated psychological factors. The condition is more frequent in females, usually young adults. Case histories regularly record the placid, passive presentation of these patients, childhood enuresis and disturbed backgrounds. The diagnosis, "hysteric', is frequent and most psychodynamic evaluations suggest the symptom represents a displacement of unacceptable sexual wishes and impulse. 2 patients treated by analytical psychotherapy are reported who, whilst fulfilling many of the criteria already noted, additionally revealed an intense desire for physical punishment. This punitive demand had less to do with unacceptable sexual wishes, than guilt at repressed aggressive drives of considerable magnitude. The role of aggression in the genesis of psychogenic urinary retention has so far been little studied.

  10. Retention in medication-assisted treatment for opiate dependence: A systematic review.

    PubMed

    Timko, Christine; Schultz, Nicole R; Cucciare, Michael A; Vittorio, Lisa; Garrison-Diehn, Christina

    2016-01-01

    Retention in medication-assisted treatment among opiate-dependent patients is associated with better outcomes. This systematic review (55 articles, 2010-2014) found wide variability in retention rates (i.e., 19%-94% at 3-month, 46%-92% at 4-month, 3%-88% at 6-month, and 37%-91% at 12-month follow-ups in randomized controlled trials), and identified medication and behavioral therapy factors associated with retention. As expected, patients who received naltrexone or buprenorphine had better retention rates than patients who received a placebo or no medication. Consistent with prior research, methadone was associated with better retention than buprenorphine/naloxone. And, heroin-assisted treatment was associated with better retention than methadone among treatment-refractory patients. Only a single study examined retention in medication-assisted treatment for longer than 1 year, and studies of behavioral therapies may have lacked statistical power; thus, studies with longer-term follow-ups and larger samples are needed. Contingency management showed promise to increase retention, but other behavioral therapies to increase retention, such as supervision of medication consumption, or additional counseling, education, or support, failed to find differences between intervention and control conditions. Promising behavioral therapies to increase retention have yet to be identified.

  11. Selenide retention by mackinawite.

    PubMed

    Finck, N; Dardenne, K; Bosbach, D; Geckeis, H

    2012-09-18

    The isotope (79)Se may be of great concern with regard to the safe disposal of nuclear wastes in deep geological repositories due to its long half-life and potential mobility in the geosphere. The Se mobility is controlled by the oxidation state: the oxidized species (Se(IV)) and (Se(VI)) are highly mobile, whereas the reduced species (Se(0) and Se(-II)) form low soluble solids. The mobility of this trace pollutant can be greatly reduced by interacting with the various barriers of the repository. Numerous studies report on the oxidized species retention by mineral phases, but only very scarce studies report on the selenide (Se(-II)) retention. In the present study, the selenide retention by coprecipitation with and by adsorption on mackinawite (FeS) was investigated. XRD and SEM analyses of the samples reveal no significant influence of Se on the mackinawite precipitate morphology and structure. Samples from coprecipitation and from adsorption are characterized at the molecular scale by a multi-edge X-ray absorption spectroscopy (XAS) investigation. In the coprecipitation experiment, all elements (S, Fe, and Se) are in a low ionic oxidation state and the EXAFS data strongly point to selenium located in a mackinawite-like sulfide environment. By contacting selenide ions with FeS in suspension, part of Se is located in an environment similar to that found in the coprecipitation experiment. The explanation is a dynamical dissolution-recrystallization mechanism of the highly reactive mackinawite. This is the first experimental study to report on selenide incorporation in iron monosulfide by a multi-edge XAS approach.

  12. Behaviorism

    ERIC Educational Resources Information Center

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  13. Understanding Recruitment and Retention in Neurological Research

    PubMed Central

    Newberry, Alyssa; Sherwood, Paula; Hricik, Allison; Bradley, Sarah; Kuo, Jean; Crago, Elizabeth; Hoffman, Leslie A.; Given, Barbara A.

    2010-01-01

    Cognitive deficits in participants and the abrupt and traumatic way in which many neurological conditions present are two examples of the unique challenges in recruiting and retaining subjects with neurological injury for research studies. The purpose of this investigation was to identify obstacles to recruitment and retention in three ongoing research studies. These studies involve persons with neurological disorders across the continuum of care, from those newly diagnosed and with emergent presentation to those with more established, chronic neurological conditions. For the purpose of this analysis, we evaluated the effectiveness of the strategies employed to improve participation rates. The first study was an NIH funded project designed to identify biomarkers of vasospasm in persons (N=496) with aneurysmal subarachnoid hemorrhage (SAH) who presented to the neurovascular intensive care unit (NINR, RO1 NR004339). The purpose of the second study was to examine bio-behavioral interactions in family caregivers (N=59) of persons with a primary malignant brain tumor (PMBT) recruited in the community setting. The third project involved recruiting persons (N=1019) within an outpatient neurosurgical center to participate in a research registry. To determine differential effectiveness of strategies, consent and attrition rates were calculated at serial points over time in three studies and recruitment and retention strategies were compared. Sentinel time points in participants' disease trajectories played a key role in determining whether those who were approached to participate gave consent and were retained, particularly in the studies involving persons with aneurysmal SAH (consent = 85%; retention = 89%) and persons with PMBTs and their caregivers (consent = 68%; retention = 83%). In addition, several specific recruiter and interviewer training techniques were associated with higher recruitment and retention. Targeted strategies to improve participation rates are vital

  14. Tritium retention in TFTR

    NASA Astrophysics Data System (ADS)

    Skinner, C. H.; Mueller, D.; Walters, R. T.; TFTR Team; Causey, R.; Luckhardt, S.; Hirooka, J.

    1996-11-01

    The large tritium inventories projected for ITER pose an important constraint in the design of plasma facing components and the selection of first wall materials. Three years of deuterium-tritium operation in TFTR has provided a special opportunity to address the issues of tritium retention in a tokamak environment. More than 18 kCi of tritium has been injected into the torus via neutral beam injection and gas puffs and approximately half of this amount was retained in the vacuum vessel.(C.H. Skinner et al.), PPPL 3172 (Jan 1995). Tritium has been successfully removed by glow discharges, exposure to room air and other techniques and it is not a constraint on continued operations. A vacuum opening is scheduled for September 1996 and we plan to extract samples of tritiated carbon dust and flakes from the limiter and vacuum vessel for elemental and chemical analysis. We will present the TFTR experience in tritium recycling, retention and removal and its implications for ITER.

  15. Des ballons pour demain

    NASA Astrophysics Data System (ADS)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  16. Mechanisms of deterioration of nutrients. [retention of flavor during freeze drying

    NASA Technical Reports Server (NTRS)

    Karel, M.; Flink, J. M.

    1975-01-01

    The retention of flavor during freeze drying was studied with model systems. Mechanisms by which flavor retention phenomena is explained were developed and process conditions specified so that flavor retention is optimized. The literature is reviewed and results of studies of the flavor retention behavior of a number of real food products, including both liquid and solid foods are evaluated. Process parameters predicted by the mechanisms to be of greatest significance are freezing rate, initial solids content, and conditions which result in maintenance of sample structure. Flavor quality for the real food showed the same behavior relative to process conditions as predicted by the mechanisms based on model system studies.

  17. Boulder Valley Kindergarten Study: Retention Practices and Retention Effects.

    ERIC Educational Resources Information Center

    Shepard, Lorrie A.; Smith, Mary Lee

    Having implemented a policy that allowed schools to retain children in kindergarten an extra year, the Boulder Valley Public School District in Colorado conducted a study to determine the cognitive and emotional benefits of retention in kindergarten and the characteristics that led to decisions about retention. The study involved a research review…

  18. Stability and Retention.

    PubMed

    Will, Leslie A

    2016-01-01

    Stability of tooth position in the broader sense considers all the forces that may act on the tooth. Reitan reported that significant forces remained in the periodontium after tooth movement, and he carried out research that demonstrated residual stretching of the crestal periodontal fibers more than 7 months after tooth movement. Brain demonstrated that severing the fibers reduced the relapse in tooth position in dogs. Edwards published a series of papers exploring the effects of surgical transection of the gingival fibers on tooth stability, recommending that circumferential fiberotomy be performed in order to increase posttreatment tooth stability. Other researchers have suggested ways to increase the stability of the incisors, which are typically most prone to relapse. Peck and Peck recommended that interproximal reduction be done to broaden the contact point. Boese also recommended interproximal reduction as part of a four-pronged approach to retention.

  19. Drug Retention Times

    SciTech Connect

    None, None

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user. Based on anecdotal evidence, most people “party” during extended time away from the work environment. Therefore, the following scenarios were envisioned: (1) a person uses an illicit drug at a party on Saturday night (infrequent user); (2) a person uses a drug one time on Friday night and once again on Saturday night (infrequent user); and (3) a person uses a drug on Friday night, uses a drug twice on Saturday night, and once again on Sunday (frequent user).

  20. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  1. Toward a Record Retention Policy

    ERIC Educational Resources Information Center

    Vaughan, Jason

    2007-01-01

    An academic library working group was charged in 2005 to create a records retention schedule and policy applicable to records containing personally identifiable information of library patrons. This group conducted a survey and extensive research, culminating in an adopted library records retention schedule and policy implemented in 2006.

  2. Maladie des vibrations

    PubMed Central

    Shen, Shixin (Cindy); House, Ronald A.

    2017-01-01

    Résumé Objectif Permettre aux médecins de famille de comprendre l’épidémiologie, la pathogenèse, les symptômes, le diagnostic et la prise en charge de la maladie des vibrations, une maladie professionnelle importante et courante au Canada. Sources d’information Une recherche a été effectuée sur MEDLINE afin de relever les recherches et comptes rendus portant sur la maladie des vibrations. Une recherche a été effectuée sur Google dans le but d’obtenir la littérature grise qui convient au contexte canadien. D’autres références ont été tirées des articles relevés. Message principal La maladie des vibrations est une maladie professionnelle répandue touchant les travailleurs de diverses industries qui utilisent des outils vibrants. La maladie est cependant sous-diagnostiquée au Canada. Elle compte 3 éléments : vasculaire, sous la forme d’un phénomène de Raynaud secondaire; neurosensoriel; et musculosquelettique. Aux stades les plus avancés, la maladie des vibrations entraîne une invalidité importante et une piètre qualité de vie. Son diagnostic exige une anamnèse minutieuse, en particulier des antécédents professionnels, un examen physique, des analyses de laboratoire afin d’éliminer les autres diagnostics, et la recommandation en médecine du travail aux fins d’investigations plus poussées. La prise en charge consiste à réduire l’exposition aux vibrations, éviter les températures froides, abandonner le tabac et administrer des médicaments. Conclusion Pour assurer un diagnostic rapide de la maladie des vibrations et améliorer le pronostic et la qualité de vie, les médecins de famille devraient connaître cette maladie professionnelle courante, et pouvoir obtenir les détails pertinents durant l’anamnèse, recommander les patients aux cliniques de médecine du travail et débuter les demandes d’indemnisation de manière appropriée. PMID:28292812

  3. Effect of Grade Retention in First Grade on Psychosocial Outcomes

    PubMed Central

    Wu, Wei; West, Stephen G.; Hughes, Jan N.

    2010-01-01

    In a 4-year longitudinal study, the authors investigated effects of retention in first grade on children’s externalizing and internalizing behaviors; social acceptance; and behavioral, cognitive, and affective engagement. From a large multiethnic sample (n = 784) of children below the median on literacy at school entrance, 124 retained children were matched with 251 promoted children on the basis of propensity scores (probability of being retained in first grade estimated from 72 baseline variables). Relative to promoted children, retained children were found to benefit from retention in both the short and longer terms with respect to decreased teacher-rated hyperactivity, decreased peer-rated sadness and withdrawal, and increased teacher-rated behavioral engagement. Retained children had a short-term increase in mean peer-rated liking and school belongingness relative to promoted children, but this advantage showed a substantial decrease in the longer term. Retention had a positive short-term effect on children’s perceived school belonging and a positive longer term effect on perceived academic self-efficacy. Retention may bestow advantages in the short-term, but longer term detrimental effects on social acceptance may lead to the documented longer term negative effects of retention. PMID:20448829

  4. Rethinking Student Retention in Community Colleges.

    ERIC Educational Resources Information Center

    Wild, Linda; Ebbers, Larry

    2002-01-01

    States that student retention is significant for measuring institutional effectiveness in the prevailing environment of accountability and budgetary constraints. Presents recommendations for increasing retention, including training staff on retention issues, reviewing admission and advising strategies affecting minority populations, and piloting…

  5. Orthodontic retention: why when and how?

    PubMed

    McNally, M; Mullin, M; Dhopatkar, A; Rock, W P

    2003-10-01

    Retention is normally required after active orthodontic tooth movement to hold the teeth in their new positions. This article reviews the principles of orthodontic retention and describes common retention regimes and appliances.

  6. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r

  7. Retention in orthodontics.

    PubMed

    Johnston, C D; Littlewood, S J

    2015-02-16

    Retention is necessary following orthodontic treatment to prevent relapse of the final occlusal outcome. Relapse can occur as a result of forces from the periodontal fibres around the teeth which tend to pull the teeth back towards their pre-treatment positions, and also from deflecting occlusal contacts if the final occlusion is less than ideal. Age changes, in the form of ongoing dentofacial growth, as well as changes in the surrounding soft tissues, can also affect the stability of the orthodontic outcome. It is therefore essential that orthodontists, patients and their general dental practitioners understand the importance of wearing retainers after orthodontic treatment. This article will update the reader on the different types of removable and fixed retainers, including their indications, duration of wear, and how they should be managed in order to minimise any unwanted effects on oral health and orthodontic outcomes. The key roles that the general dental practitioner can play in supporting their patients wearing orthodontic retainers are also emphasised.

  8. Data Retention and Anonymity Services

    NASA Astrophysics Data System (ADS)

    Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

    The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

  9. Models of retention of adamantylamidrazones in reversed-phase high-performance liquid chromatography

    NASA Astrophysics Data System (ADS)

    Prokopov, S. V.; Kurbatova, S. V.

    2011-05-01

    Rules governing the chromatographic behavior of some amidrazones of the adamantane series were studied under the conditions of reversed-phase high-performance liquid chromatography. The characteristics of the retention of sorbates in elution by aqueous-acetonitrile phases with various compositions were calculated. Correlations between the structure and physicochemical characteristics of sorbate molecules and their retention were studied.

  10. The Impact of Principal Leadership on Working Conditions and Teacher Retention in North Carolina Middle Schools

    ERIC Educational Resources Information Center

    Tomon, Catherine

    2009-01-01

    Research indicates that administrative leadership is the most important factor in determining the climate of a school, and there are specific leadership attributes such as improving working conditions that promote retention. This study seeks to identify leadership behaviors that positively affect quality teacher retention among two particular…

  11. Retention, Persistence, and Enrollment Management: An Exploration of Organizational Models

    ERIC Educational Resources Information Center

    Bartlett, Stacy A.

    2013-01-01

    Low student retention and persistence continues to be a major problem within American higher education (Elkins, Braxton, & James, 2000; Kalsbeek & Hossler, 2010; Kezar, 2004; Tinto, 2006-2007). Less is known about the institutional organizational behavior influence on student persistence (Berger, 2001-2002); and while enrollment management…

  12. Fission gas retention and axial expansion of irradiated metallic fuel

    SciTech Connect

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1986-05-01

    Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin.

  13. A Job Retention Model for Individuals with Mental Retardation

    ERIC Educational Resources Information Center

    Fornes, Sandra

    2006-01-01

    This structured literature review examines the literature and addresses issues of job retention for adult workers with moderate to mild mental retardation (MR), investigating the relationships between work-related social behaviors, self-determination, person-job congruency of individuals with MR, and their job performance and job satisfaction with…

  14. Professional Development and Mentoring in Support of Teacher Retention

    ERIC Educational Resources Information Center

    Rodgers, Christopher; Skelton, Jillian

    2014-01-01

    The authors' discussion will describe how teacher retention is in jeopardy. Many novice teachers are ill-prepared to handle the rigorous school days and challenging students academically and behaviorally (Stansbury & Zimmerman, 2002). Novice teachers need guidance and support to ease tensions and stress levels which arise during teaching…

  15. Post-operative urinary retention.

    PubMed

    Steggall, Martin; Treacy, Colm; Jones, Mark

    Urinary retention is a common complication of surgery and anaesthesia. The risk of post-operative urinary retention is increased following certain surgical procedures and anaesthetic modalities, and with patients' advancing age. Patients at increased risk of post-operative urinary retention should be identified before surgery or the condition should be identified and treated in a timely manner following surgery. If conservative measures do not help the patient to pass urine, the bladder will need to be drained using either an intermittent catheter or an indwelling urethral catheter, which can result in catheter-associated urinary tract infections. This article provides an overview of normal bladder function, risk factors for developing post-operative urinary retention, and treatment options. Guidance drawn from the literature aims to assist nurses in identifying at-risk patients and inform patient care.

  16. EA Shuttle Document Retention Effort

    NASA Technical Reports Server (NTRS)

    Wagner, Howard A.

    2010-01-01

    This slide presentation reviews the effort of code EA at Johnson Space Center (JSC) to identify and acquire databases and documents from the space shuttle program that are adjudged important for retention after the retirement of the space shuttle.

  17. Diversity and Retention in Engineering

    ERIC Educational Resources Information Center

    Davis, Cinda-Sue G.; Finelli, Cynthia J.

    2007-01-01

    The authors describe three initiatives designed to increase the academic achievement and retention of historically underrepresented students (including females and underrepresented students of color) in engineering. (Contains 2 tables.)

  18. Turnover: strategies for staff retention.

    PubMed

    SnowAntle, S

    1990-01-01

    This discussion has focused on a number of areas where organizations may find opportunities for more effectively managing employee retention. Given the multitude of causes and consequences, there is no one quick fix. Effective management of employee retention requires assessment of the entire human resources process, that is, recruitment, selection, job design, compensation, supervision, work conditions, etc. Regular and systematic diagnosis of turnover and implementation of multiple strategies and evaluation are needed (Mobley, 1982).

  19. Retention Rate by Ethnicity. Information Capsule.

    ERIC Educational Resources Information Center

    Baldwin, Anne

    This document discusses retention rate based on ethnicity for Miami-Dade Community College (M-DCC) for December 2002. The study found that the 2001 Fall-Spring retention rates increased among all ethnic groups. The total college retention rate rose by 2.7 percentage points to 75.2%. Among individual groups, the highest retention rate of 76.9% was…

  20. Injectabilite des coulis de ciment dans des milieux fissures

    NASA Astrophysics Data System (ADS)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  1. Influence of hydrologic loading rate on phosphorus retention and ecosystem productivity in created wetlands. Final report

    SciTech Connect

    Mitsch, W.J.; Cronk, J.K.

    1995-01-01

    Four 2- to 3-ha constructed freshwater riparian wetlands in Lake County, Illinois, were subjected to two hydrologic regimes of pumped river water to simulate nonpoint source pollution. The experimental wetlands at the Des Plaines River Wetland Demonstration Project were designed to develop and test wetland design principles, construction methods, and management programs needed to create and maintain wetlands for the purposes of water quality management, flood control, and fish and wildlife habitat. High-flow wetlands (HFW) with short retention times received 34 to 38 cm of river water per week, and low-flow wetlands (LFW) with high retention times received 10 to 15 cm per week. This report summarizes research results for phosphorus dynamics and retention, macrophyte development, periphyton productivity, and overall water column metabolism through 1992. All of these functions were hypothesized to be related to hydrologic conditions.

  2. Charge retention of twisted nematic liquid-crystal displays

    NASA Astrophysics Data System (ADS)

    Yang, K. H.

    1990-01-01

    A simulated thin-film transistor (TFT) circuit has been built to drive the twisted nematic (TN) cell for the measurements of charge retention and the transmission versus peak voltage applied to the drain electrode of the simulated TFT using the gate pulse width as a parameter. The established rule that the transmission of the TN cell depends only on the rms voltage applied to the cell has been confirmed by calculating the rms voltage of the charge retention curves in correlation with the measured transmissions. The deviation of the decaying charge retention curves from the exponential behavior has been observed and can be qualitatively explained by a combination of the dielectric and transport properties of nematic liquid-crystal medium.

  3. Foliar retention and leachability of submicron plutonium and americium particles

    SciTech Connect

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.

    1981-01-01

    Submicron particles of Pu and Am were aerosolized, deposited onto foliage of bush bean (Phaseolus vulgaris L.), and their subsequent retention and behavior determined. Particles having mass median diameters of <1 ..mu..m are not readily dislodged from leaf surfaces at wind speeds of approx. 400 m min/sup -1/. Under conditions of simulated rainfall, weathering half-times range from 164 to 1000 days, and are dependent on both particle size and initial solubility. The residence time of contaminants on foliar surfaces prior to leaching influences subsequent foliar retention and leachate characteristics. Foliar retention of particles ranges from 20 to 92% and is dependent on particle size of Pu- and Am-oxides, chemical form of Pu, and environmental conditions such as humidity, simulated rainfall, and acidity of the simulated rain.

  4. Fuel retention studies on MAST

    NASA Astrophysics Data System (ADS)

    Mast Team Huang, J.; Lisgo, S.; Maddison, G.

    2011-08-01

    Fuel retention has been studied on MAST using gas-balance analysis. With 8-15 min of inter-shot helium glow-discharge cleaning (4He-GDC), the wall retention fraction stays very high (>90%) during the flat-top of the plasma current, indicating this component is dominant during the discharge. Recovery of wall conditioning with 4He-GDC suggests the retention process is dominated by direct implantation of particles in shallow surface layers. The effect of 4He-GDC duration on the particle balance has also been investigated. It is shown that when there was no preceding 4He-GDC, the wall pumping capacity was reduced, causing higher plasma density and tank pressure for the next shot.

  5. CHLORIDE RETENTION IN EXPERIMENTAL HYDRONEPHROSIS

    PubMed Central

    Keith, Norman M.; Pulford, D. Schuyler

    1923-01-01

    1. In acute experimental hydronephrosis chloride retention occurs as well as retention of water, urea, and phenolsulfonephthalein. 2. If both water and chlorides are retained there may be no appreciable rise in the plasma chloride content. 3. When chlorides are retained, but not water, the chloride content of the plasma rises strikingly. 4. After the removal of the ureteral obstruction in acute hydronephrosis all renal functions, water, urea, and chloride excretion, may be rapidly restored in equal degree, or the chlorides may be retained temporarily while there is free excretion of water and urea. 5. In chronic hydronephrosis adequate daily excretion of urea and chlorides may be maintained by a compensatory polyuria. 6. Chloride retention or an abnormal chloride excretion may occur in certain renal lesions when there is no change in the urea, phenolsulfonephthalein, or water excretion. PMID:19868720

  6. Lake retention of manufactured nanoparticles.

    PubMed

    Koelmans, A A; Quik, J T K; Velzeboer, I

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hydraulic loadings covered the widest possible range among existing lakes. Sedimentation accounted for natural colloid as well as suspended solid settling regimes. An ENP-specific mixed sedimentation regime is proposed. This regime combines ENP sedimentation through slow settling with natural colloids from the water column, with faster settling with suspended solids from a selected part of the water column. Although sedimentation data and hydrodynamic concepts as such were not new, their first time combination or application to ENPs shows in which cases lake retention is important for these particles. In combination with ENP emission data, lake retention translates directly into potential risks of ENPs for lake benthic communities.

  7. Genetic programming based quantitative structure-retention relationships for the prediction of Kovats retention indices.

    PubMed

    Goel, Purva; Bapat, Sanket; Vyas, Renu; Tambe, Amruta; Tambe, Sanjeev S

    2015-11-13

    The development of quantitative structure-retention relationships (QSRR) aims at constructing an appropriate linear/nonlinear model for the prediction of the retention behavior (such as Kovats retention index) of a solute on a chromatographic column. Commonly, multi-linear regression and artificial neural networks are used in the QSRR development in the gas chromatography (GC). In this study, an artificial intelligence based data-driven modeling formalism, namely genetic programming (GP), has been introduced for the development of quantitative structure based models predicting Kovats retention indices (KRI). The novelty of the GP formalism is that given an example dataset, it searches and optimizes both the form (structure) and the parameters of an appropriate linear/nonlinear data-fitting model. Thus, it is not necessary to pre-specify the form of the data-fitting model in the GP-based modeling. These models are also less complex, simple to understand, and easy to deploy. The effectiveness of GP in constructing QSRRs has been demonstrated by developing models predicting KRIs of light hydrocarbons (case study-I) and adamantane derivatives (case study-II). In each case study, two-, three- and four-descriptor models have been developed using the KRI data available in the literature. The results of these studies clearly indicate that the GP-based models possess an excellent KRI prediction accuracy and generalization capability. Specifically, the best performing four-descriptor models in both the case studies have yielded high (>0.9) values of the coefficient of determination (R(2)) and low values of root mean squared error (RMSE) and mean absolute percent error (MAPE) for training, test and validation set data. The characteristic feature of this study is that it introduces a practical and an effective GP-based method for developing QSRRs in gas chromatography that can be gainfully utilized for developing other types of data-driven models in chromatography science.

  8. Treating Non-Retentive Encopresis with Rewarded Scheduled Toilet Visits

    PubMed Central

    Boles, Richard E; Roberts, Michael C; Vernberg, Eric M

    2008-01-01

    We evaluated the effects of rewarded scheduled toilet sits on non-retentive encopretic behavior of an elementary-school student receiving services for serious emotional disturbance. A multidisciplinary team implemented the 8-week intervention using a multiple baseline across settings design. The results showed an increase in sitting on the toilet and a decline in encopretic episodes in both school and home settings. These findings support the use of a behavioral intervention for children with significant behavioral disorders within a classroom setting. PMID:22477690

  9. Grundlagen des Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  10. Meeting Individual Needs Fosters Retention.

    ERIC Educational Resources Information Center

    Artman, Johanne I.; Gore, Robert C.

    A 1991 study of non-returning students at Del Mar College (DMC), in Corpus Christi, Texas, revealed that only 37.9% of these students were actual dropouts (i.e., had failed to accomplish their educational goals, and had no plans to take up further study). Retention studies conducted in Texas between 1985 and 1989 have shown that DMC has…

  11. Strategies for improving employee retention.

    PubMed

    Verlander, Edward G; Evans, Martin R

    2007-03-28

    This article proposes a solution to the perennial problem of talent retention in the clinical laboratory. It includes the presentation of 12 strategies that may be used to significantly improve institutional identity formation and establishment of the psychological contract that employees form with laboratory management. Identity formation and psychological contracting are deemed as essential in helping reduce employee turnover and increase retention. The 12 conversational strategies may be used as a set of best practices for all employees, but most importantly for new employees, and should be implemented at the critical moment when employees first join the laboratory. This time is referred to as "retention on-boarding"--the period of induction and laboratory orientation. Retention on-boarding involves a dialogue between employees and management that is focused on the psychological, practical, cultural, and political dimensions of the laboratory. It is placed in the context of the modern clinical laboratory, which is faced with employing and managing Generation X knowledge workers. Specific topics and broad content areas of those conversations are outlined.

  12. Implicit Memory: Retention without Remembering.

    ERIC Educational Resources Information Center

    Roediger, Henry L., III

    1990-01-01

    Reviews recent research on retention that is demonstrated without conscious recollection, such as the ability to tie shoelaces or drive a car. Suggests that future research in this field may have implications for such educational issues as the transfer of training and the carryover of abstract classroom learning to problems in other contexts. (EVL)

  13. Maslow's Hierarchy and Student Retention.

    ERIC Educational Resources Information Center

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  14. A Research Study in Retention.

    ERIC Educational Resources Information Center

    Knibbe, Marie Vannozzi; Dusewicz, Russell A.

    A study of the Center for Literacy's (CFL) program was conducted to provide information on retention and attrition in an urban, open-entry/open-exit, individualized, goal-based literacy program. An exploratory analysis that used student and tutor records from 1985 through 1989 provided a summary of demographics and attendance patterns. This…

  15. Three Recruitment and Retention Surveys.

    ERIC Educational Resources Information Center

    Bronx Community Coll., NY.

    This three-part report summarizes methodology and findings of three recruitment and retention studies conducted by the Bronx Community College (BCC) during 1979-1980. Part I examines a survey of enrolled students conducted to determine student attitudes toward BCC, the services that were most in demand, the reasons for attending BCC, and student…

  16. Academic Advising for Retention Purposes.

    ERIC Educational Resources Information Center

    Kazazes, Barbara A.

    An effective academic advising system can assist in the retention of two-year college students; however, the institution and its faculty must be committed to providing such a system. Establishing a successful advising system would require the following: (1) a clear distinction must be made between academic advising and course scheduling; (2)…

  17. Course Retention Analysis. Focus Study.

    ERIC Educational Resources Information Center

    Mount San Antonio Coll., Walnut, CA.

    A study was conducted at Mount San Antonio College (MSAC), California, to analyze patterns in credit course retention between fall 1986 and spring 1989. The study investigated the development of course prerequisites based on faculty perceptions of the skills necessary for success and minimal skill levels associated with success; student assessment…

  18. Institutionalization of a Retention Model

    NASA Astrophysics Data System (ADS)

    Davis, E. J.; Campbell, A.

    2006-05-01

    Bowie State University and NASA Goddard Space Flight Center have, for the past 10 years, worked diligently together to enhance the science, mathematics, engineering and technology (SMET) domain. Efforts made, because of a Model Institutions for Excellence (MIE) Award, have changed the landscape of the SMET domain by increasing the retention and graduation rates, the number of students entering graduate and professional schools, and the number of students entering SMET related careers for minorities and women. Several initiatives a Scholarship Program, PRISEM Tutoring Center, Safety-net Program, Research emphasis, Focused Mentoring, a Summer Academy for accepted incoming students, a Bridge Program for students needing assistance being admitted to the University, the RISE Program and the Bowie State Satellite Operations and Control Center (BSOCC) provide the nurturing, mentoring, and opportunities for our students. As a result of efforts made, the retention rate has increase to approximately 80%, the graduation rate has increased 40%, and 85% of the SMET students are now interested or entering graduate and professional schools. Successes that have been documented by various assessment activities have led to the institutionalization of the Retention Model of the MIE Initiative. It is anticipated that University-wide application of the retention model will prove the incentives necessary to obtain similar results as the MIE Initiative.

  19. Reticulation des fibres lignocellulosiques

    NASA Astrophysics Data System (ADS)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  20. La diffraction des neutrons et des rayons X pour l'étude structurale des liquides et des verres

    NASA Astrophysics Data System (ADS)

    Fischer, H. E.; Salmon, P. S.; Barnes, A. C.

    2003-02-01

    La compréhension de mainte propriété physique d'un verre ou d'un liquide nécessite la connaissance des facteurs de structure partiels (PSFs) qui décrivent chacun la distribution d'une espèce atomique autour d'une autre. La technique de diffraction des neutrons avec substitution isotopique (NDIS) [1,2,3], ayant bien réussi a déterminer les PSFs de certains composés [4,5], est pourtant restreinte aux isotopes présentant un contraste suffisant en longueur de diffusion. D'un autre cote, la technique de diffusion anomale des rayons X (AXS ou AXD) [6] permet de faire varier la longueur de diffusion d'une espèce atomique pourvu que son énergie d'absorption soit à la fois accessible et suffisamment élevée pour donner un assez grand transfert du moment. La combinaison des techniques de diffraction des neutrons (avec ou sans substitution isotopique) et de diffraction des rayons X (avec ou sans diffusion anomale) peut donc permettre d'obtenir un meilleur contraste en longueurs de diffusion pour un système donné, mais exige une analyse de données plus soignée pour pouvoir bien tenir compte des erreurs systématiques qui sont différentes pour les 2 techniques [7]. Pour les atomes ayant des distributions électroniques quasi-sphériques, e.g. dans le cas d'un alliage liquide, la combinaison des techniques de NDIS et de diffraction des rayons X s'est déjà montrée très avantageuse pour la détermination des PSFs [8,9]. Dans le cas des verres ayant d'importantes liaisons covalentes, l'effective combinaison des 2 techniques peut être moins directe mais facilitée lorsqu'il s'agit des atomes de grand Z [10,11]. Nous présentons ici un sommaire du méthode et quelques exemples des résultats.

  1. Population Ration, Intermarriage and Mother Tongue Retention

    ERIC Educational Resources Information Center

    Kuo, Eddie C. Y.

    1978-01-01

    An explanatory model of the relationship between mother tongue retention, population ratio, and intermarriage is presented. In general, data collected on mother tongue retention in Singapore, a multilingual and multiethnic society, support the proposed model. (DS)

  2. 12 CFR 202.12 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 2 2011-01-01 2011-01-01 false Record retention. 202.12 Section 202.12 Banks... OPPORTUNITY ACT (REGULATION B) § 202.12 Record retention. (a) Retention of prohibited information. A creditor...) Applications. For 25 months (12 months for business credit, except as provided in paragraph (b)(5) of...

  3. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  4. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  5. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  6. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  7. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  8. Persistence-Retention. Snapshot™ Report, Spring 2015

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2015

    2015-01-01

    This Snapshot Report offers information on student persistence and retention rates for 2009-2013. It offers data on the following: (1) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year Private Nonprofit Institutions; (2) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year…

  9. Persistence-Retention. Snapshot™ Report, Spring 2014

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2014

    2014-01-01

    This snapshot report provides information on student persistence and retention rates for Spring 2014. Data is presented in tabular format on the following: (1) First-Year Persistence and Retention Rates by Starting Enrollment Intensity (all institutional sectors); (2) First-Year Persistence and Retention Rates by Age at College Entry (all…

  10. Reframing Retention Strategy: A Focus on Progress

    ERIC Educational Resources Information Center

    Spittle, Brian

    2013-01-01

    Few words have dominated the vocabulary of college retention as has the word "persistence." Many institutions still struggle to engage faculty and administrators in building campuswide retention efforts, to find the organizational levers that translate the abstractions and complexities of retention theory into scalable and durable initiatives, and…

  11. Reframing Retention Strategy: A Focus on Profile

    ERIC Educational Resources Information Center

    Kalsbeek, David H.; Zucker, Brian

    2013-01-01

    Over 35 years of retention theory and literature have acknowledged the importance of institutional and student profiles in accounting for cross-sectional differences in retention and completion rates between types of colleges and universities. The first "P" within a 4 Ps framework of student retention--"profile"--recognizes that an institution's…

  12. Designing Online Courses to Promote Student Retention

    ERIC Educational Resources Information Center

    Dietz-Uhler, Beth; Fisher, Amy; Han, Andrea

    2008-01-01

    Although the issue of student retention is a campus-wide one, it is of special interest in online distance learning courses, where retention rates are reported to be lower than in face-to-face classes. Among the explanations and theories of retention rates in online courses, one that struck us as most useful is a structural one, namely, course…

  13. Missile Aerodynamics (Aerodynamique des Missiles)

    DTIC Science & Technology

    1998-11-01

    guerre froide la production des missiles a baisse’, avec pour consequence une diminution des budgets de d6veloppement. Les nouveaux types de conflits ...Roma) Directeur - Gestion de l’information LUXEMBOURG (Recherche et developpement) - DRDGI 3 Voir Belgique Ministbre de la Difense nationale NORVEGE

  14. Do We Have a Retention Problem ... Or Do We Have a Problem "about" Retention?

    ERIC Educational Resources Information Center

    Butler, Lawrence

    2011-01-01

    This paper deals with the "problem" of student retention in higher education. But unlike most, this paper focuses not on the problem of retention "per se" but rather on how institutional leaders think about student retention, completion, and success--how the way they frame their concerns about retention can give rise to a different sort of…

  15. Oxygen plasma immersion ion implantation treatment to enhance data retention of tungsten nanocrystal nonvolatile memory

    SciTech Connect

    Wang, Jer-Chyi Chang, Wei-Cheng; Lai, Chao-Sung; Chang, Li-Chun; Ai, Chi-Fong; Tsai, Wen-Fa

    2014-03-15

    Data retention characteristics of tungsten nanocrystal (W-NC) memory devices using an oxygen plasma immersion ion implantation (PIII) treatment are investigated. With an increase of oxygen PIII bias voltage and treatment time, the capacitance–voltage hysteresis memory window is increased but the data retention characteristics become degraded. High-resolution transmission electron microscopy images show that this poor data retention is a result of plasma damage on the tunneling oxide layer, which can be prevented by lowering the bias voltage to 7 kV. In addition, by using the elevated temperature retention measurement technique, the effective charge trapping level of the WO{sub 3} film surrounding the W-NCs can be extracted. This measurement reveals that a higher oxygen PIII bias voltage and treatment time induces more shallow traps within the WO{sub 3} film, degrading the retention behavior of the W-NC memory.

  16. Enhanced methodology for porting ion chromatography retention data.

    PubMed

    Park, Soo Hyun; Shellie, Robert A; Dicinoski, Greg W; Schuster, Georg; Talebi, Mohammad; Haddad, Paul R; Szucs, Roman; Dolan, John W; Pohl, Christopher A

    2016-03-04

    Porting is a powerful methodology to recalibrate an existing database of ion chromatography (IC) retention times by reflecting the changes of column behavior resulting from either batch-to-batch variability in the production of the column or the manufacture of new versions of a column. This approach has been employed to update extensive databases of retention data of inorganic and organic anions forming part of the "Virtual Column" software marketed by Thermo Fisher Scientific, which is the only available commercial optimization tool for IC separation. The current porting process is accomplished by performing three isocratic separations with two representative analyte ions in order to derive a porting equation which expresses the relationship between old and new data. Although the accuracy of retention prediction is generally enhanced on new columns, errors were observed on some columns. In this work, the porting methodology was modified in order to address this issue, where the porting equation is now derived by using six representative analyte ions (chloride, bromide, iodide, perchlorate, sulfate, and thiosulfate). Additionally, the updated porting methodology has been applied on three Thermo Fisher Scientific columns (AS20, AS19, and AS11HC). The proposed approach showed that the new porting methodology can provide more accurate and robust retention prediction on a wide range of columns, where average errors in retention times for ten test anions under three eluent conditions were less than 1.5%. Moreover, the retention prediction using this new approach provided an acceptable level of accuracy on a used column exhibiting changes in ion-exchange capacity.

  17. Retention in the Canadian Forces

    DTIC Science & Technology

    2007-12-14

    the reasons that contribute to their personnel and retention problems . The research will then focus on the implemented solutions that the ADF has... one place Desire to live in own home 4 Low morale in work environment Desire to stay in one place Better career prospects in civilian life To... on my career management Low morale in my work environment and impact of job demands on family/personal life A desire for more challenging work

  18. Research and identification of tranquillizers - use of retention index.

    PubMed Central

    Courtot, D.

    1976-01-01

    At the request of the Service des Haras, our laboratory works on the toxicological problems of the sport-horse. These studies have resulted in the setting up of an anti-doping control for equestrian competitions of various types, not only flat racing. During events, horses, must be calm and docile to the riders' order. Frequently, the latter use tranquillizers to try and win events. The analytical method for the research and identification of these compounds is described. The technique involves successively: 1. alkalinisation of the sample - saliva, blood or urine after enzymatic hydrolysis. 2. extraction with diethyl ether - the recovery is 70% to 90% depending upon the drug. 3. determination by gas-liquid chromatography with use of a retention index for qualitative analysis. We can detect up to fifteen tranquillizers in any one sample, even when present at such low concentrations as found in saliva. The use of the retention index is a reliable method for qualitative analysis. For example, the method has been used for three years, during which period the rentention index of acetylpromazine remained at 3240 +/- 7. The chromatographic analysis was performed on 3% OV-17 at 290 degrees. The chromatographic analysis has been performed by three columns of different polarity (OV-1; OV-17; SP-2250). If on the three columns, the retention index of one peak is the same as that of the tranquilizer, a further confirmation is made with the use of a thermionic detector specific for nitrogenous drugs. In conclusion, this method which is sufficiently precise and specific has been used for anti-doping control. PMID:1000160

  19. Acute urinary retention among astronauts.

    PubMed

    Stepaniak, Philip C; Ramchandani, Suneil R; Jones, Jeffrey A

    2007-04-01

    Although acute urinary retention (AUR) is not commonly thought of as a life-threatening condition, its presentation in orbit can lead to a number of medical complications that could compromise a space mission. We report on a middle-aged astronaut who developed urinary retention during two spaceflights. On the first mission of note, the astronaut initially took standard doses of promethazine and scopolamine before launch, and developed AUR immediately after entering orbit. For the first 3 d, the astronaut underwent intermittent catheterizations with a single balloon-tipped catheter. Due to the lack of iodine solution on board and the need for the astronaut to complete certain duties without interruption, the catheter was left in place for a total of 4 d. Although the ability to void returned after day 7, a bout of AUR reemerged on day 10, 1 d before landing. On return to Earth, a cystometrogram was unremarkable. During the astronaut's next mission, AUR again recurred for the first 24 h of microgravity exposure, and the astronaut was subsequently able to void spontaneously while in space. This report details the presentation of this astronaut, the precautions that were taken for space travel subsequent to the initial episode of AUR, and the possible reasons why space travel can predispose astronauts to urinary retention while in orbit. The four major causes of AUR--obstructive, pharmacologic, psychogenic, and neurogenic-are discussed, with an emphasis on how these may have played a role in this case.

  20. Toward a Greater Understanding of Hispanic Undergraduate Retention at a Private Christian University Using Narrative Inquiry and Autoethnographic Methods

    ERIC Educational Resources Information Center

    Sanchez, Robert

    2016-01-01

    Student retention is considered a complex human behavior. Adding to the complex nature of student retention is the ever changing landscape of higher education due in large part to the growth of Hispanic undergraduate student enrollment on college campuses. While notable gains have been made increasing the number of Hispanic students graduating…

  1. Deuterium retention in tungsten films after different heat treatments

    NASA Astrophysics Data System (ADS)

    Wang, P.; Jacob, W.; Elgeti, S.

    2015-01-01

    Tungsten films deposited by magnetron sputtering on polycrystalline tungsten substrates were used as a model system to study the influence of the film microstructure on deuterium retention behavior. Different microstructures were produced by annealing the films up to recrystallization temperature and the corresponding structural changes were investigated by scanning electron microscopy combined with focused ion beam (FIB) cross sectioning. The influence of the induced structural changes on D retention was investigated by both nuclear reaction analysis and temperature-programmed desorption. D concentration in the investigated W films is higher than in polycrystalline bulk tungsten by a factor of 3. D retention in the films decreases as a function of annealing temperature. After annealing at 2000 K, FIB cross-section images reveal that cavities appeared at the grain boundaries within the film and at the initial interface between the W film and W substrate. This new microstructure strongly affects the D depth profile and leads to the increase of D retention. Although a further increase of the holding time at 2000 K or an increase of the annealing temperature to 2150 K lead to the reduction of the retained D amount, the D concentration in the recrystallized W films cannot be reduced to a level as low as that of bulk W recrystallized at 2000 K for 30 min.

  2. Effect of temperature on data retention of SNOS transistors

    SciTech Connect

    Miller, S.L.

    1986-01-01

    Understanding thermal effects on data retention of MNOS transistors is of fundamental importance in characterizing and predicting the behavior of fully functional parts in real environments. Much work, both theoretical and experimental, has been done in this area, with reasonable agreement being made between the two when appropriate assumptions were made. Most of this work was performed on metal gate, APCVD nitride, p-channel devices. The current paper studies temperature effects in modern Si gate, LPCVD nitride, n-channel transistors (the same transistors used in Sandia's SA2999-2, a 16K EEPROM with 5 year retention over the temperature range - 55 to 80/sup 0/C utilizing 16V, 230..mu..S/2500..mu..S write/erase pulses). A major result of the present study is the fundamental difference in the response of the two logic states (trapped electrons vs trapped holes) in thermally varying environments. Here, the effects of hole trapping are not negligible, as has been the case of previous investigations on older technologies. Data are presented from our transistors which illustrate the fundamentally different ways that trapped electrons and holes respond to a thermally varying environment. Two primary cases are examined: (1) program at a fixed temperature and store at different temperatures, (2) program at different temperatures and store at a fixed temperature. The results are directly applicable to developing data retention screens and for developing strategies to increase data retention time.

  3. Neckband retention for lesser snow geese in the western Arctic

    USGS Publications Warehouse

    Samuel, M.D.; Goldberg, D.R.; Smith, A.E.; Baranyuk, W.; Cooch, E.G.

    2001-01-01

    Neckbands are commonly used in waterfowl studies (especially geese) to identify individuals for determination of movement and behavior and to estimate population parameters. Substantial neckband loss can adversely affect these research objectives and produce biased survival estimates. We used capture, recovery, and observation histories for lesser snow geese (Chen caerulescens caerulescens) banded in the western Arctic, 1993-1996, to estimate neckband retention. We found that neckband retention differed between snow goose breeding colonies at Wrangel Island, Russia, and Banks Island, Northwest Territories, Canada. Male snow geese had higher neckband loss than females, a pattern similar to that found for Canada geese (Branta canadensis) and lesser snow geese in Alaska. We found that the rate of neckband loss increased with time, suggesting that neckbands are lost as the plastic deteriorates. Survival estimates for geese based on resighting neckbands will be biased unless estimates are corrected for neckband loss. We recommend that neckband loss be estimated using survival estimators that incorporate recaptures, recoveries, and observations of marked birds. Research and management studies using neckbands should be designed to improve neckband retention and to include the assessment of neckband retention.

  4. University Executive Team's Collective Leadership and Its Impact on Student Retention on Catholic Campuses

    ERIC Educational Resources Information Center

    Perez, Michelle

    2016-01-01

    Although individual leadership behaviors, particularly those of a college president have been studied extensively, the possibility of leading at the group level, particularly the relationship of leadership behaviors of the college executive team and its effect on student retention, remains unclear. Based on 68 college executive leader responses,…

  5. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  6. Retention at Departments of Physics

    NASA Astrophysics Data System (ADS)

    Muller, Rafael; Rosa, Luis

    2013-03-01

    A thriving physics department is the end result of many actions, taken over time, that results in the development of a sense of community between the faculty and the students. As part of this sense of community, gifted students must receive special attention and innovative ideas must be incorporated to successfully accommodate the needs of these students. We have found that the best retention strategy for gifted undergraduates is the total involvement of them in undergraduate research projects and also the development of leadership in extracurricular activities within the department. A careful employment strategy is needed to secure a faculty committed to the goals of the community.

  7. Preheating temperature effect on tritium retention in VPS-W

    SciTech Connect

    Sato, M.; Uchimura, H.; Toda, K.; Oya, Y.; Okuno, K.; Tokunaga, T.; Watanabe, H.; Yoshida, N.; Hatano, Y.; Kasada, R.; Kimura, A.; Nagasaka, T.

    2015-03-15

    The W coating by Vacuum Plasma Spraying (VPS) technology is thought to be reasonable for most plasma facing components in future fusion reactors. In this paper the deuterium retention behavior for the Vacuum Plasma Spraying (VPS) tungsten (W) coating has been studied to demonstrate the tritium retention as a function of heating temperature. It has been found that two major deuterium desorption stages were observed at the temperature regions of 400 - 700 K (Stage 1) and 900 - 1100 K (Stage 2), considering that Stage 1 has been linked to the desorption of deuterium trapped by near surface and intrinsic defects, and Stage 2 has been related to the desorption of deuterium bound to impurities as C-D bonds. By heating the sample above 673 K, the major peak of C-1s shifted from C-O bond to C-C bond, where the retention of deuterium as Stage 2 has increased. Therefore it indicates that the hydrogen isotope retention was controlled by the amount of C-C bond in VPS, most of which was contaminated during the VPS coating process. The comparison of several samples (VPS-W with shading, VPS-W without shading and Polycrystalline W (PCW)) shows that the carbon impurity has a large affinity with deuterium and makes stable trapping states compared to that with intrinsic defects and grain boundaries. However, most of them was reduced by heating at 1173 K. Therefore, heating treatment is quite important to get rid of carbon impurities and refrain higher tritium retention in VPS. (authors)

  8. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  9. The Retention of Female Unrestricted Line Officers

    DTIC Science & Technology

    2005-03-01

    PS y• s’TANTIA PER SCIENTIAM NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS THE RETENTION OF FEMALE UNRESTRICTED LINE OFFICERS by Elena G...Title (Mix case letters) 5. FUNDING NUMBERS The Retention of Female Unrestricted Line Officers 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND...public release; distribution is unlimited. 13. ABSTRACT (maximum 200 words) This thesis analyzes the retention of female Naval officers, focusing on the

  10. Fission-product retention in HTGR fuels

    SciTech Connect

    Homan, F.J.; Kania, M.J.; Tiegs, T.N.

    1982-01-01

    Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed.

  11. Impact of Materials Defects on Engine Structures Integrity (L’Impact des Defauts des Materiaux sur l’Integrite des Structures des Moteurs)

    DTIC Science & Technology

    1993-04-01

    participants ont fait le point des aspects traitement et contr6le des mat~riaux. en mettant I’accent sur les materiaux constitutifs des disques moteur en...adapte. Pour le physicien. un -d~faur’" peut tres bien se resumer A une imperfection de Ia structure rericulaire d’un materiau. En science des materiaux ... materiaux sur l~integrite des structures des moteurs Defence Research Ag~ency Matenials & Structures Department Farnborough. Hants GUt 14 fITD Rovaume-Uni

  12. Clearance kinetics of biomaterials affects stem cell retention and therapeutic efficacy.

    PubMed

    Lai, Chia Y; Wu, Pei J; Roffler, Steve R; Lee, Sho T; Hwang, Shiaw M; Wang, Shoei S; Wang, Kuan; Hsieh, Patrick C H

    2014-02-10

    The use of biomaterial carriers to improve the therapeutic efficacy of stem cells is known to augment cell delivery, retention, and viability. However, the way that carrier clearance kinetics boosts stem cell delivery and impacts stem cell function remains poorly characterized. In this study, we designed a platform to simultaneously quantify carrier clearance and stem cell retention to evaluate the impact of carrier clearance kinetics on stem cell retention. Additionally, a murine model of hindlimb ischemia was employed to investigate the effects of various cell retention profiles on mitigating peripheral arterial disease. To image the in vivo behaviors of material and cells, we used biotinylated hyaluronan with fluorescently labeled streptavidin and Discosoma sp. Red (Ds-Red)-expressing human mesenchymal stem cells. We found that the retention of transplanted stem cells was closely related to the remaining biomaterial. Furthermore, therapeutic effectiveness was also affected by stem cell retention. These results demonstrate that low-molecular-weight hyaluronan had a slow clearance and high cell retention profile, improving the therapeutic efficacy of human stem cells.

  13. Formation and retention of methane in coal

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  14. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  15. Predicting health plan member retention from satisfaction surveys: the moderating role of intention and complaint voicing.

    PubMed

    Huppertz, John W

    2008-01-01

    Many health plans have tried to increase member retention by improving their scores on customer satisfaction surveys. However, prior research has demonstrated weak relationships between member satisfaction and retention, suggesting that other variables are needed to understand how satisfaction impacts member retention. In a longitudinal study 4,806 health plan members who completed satisfaction surveys were re-assessed three years later; we compared measures of satisfaction, intention, and complaining behavior from voluntary disenrollees and retained members. The relationship between satisfaction and retention was moderated by members' intentions to disenroll. The findings suggest that health plans can enhance the predictive validity of their satisfaction surveys by including measures of both satisfaction and intentions.

  16. Peste des petits ruminants

    PubMed Central

    Parida, S.; Muniraju, M.; Mahapatra, M.; Muthuchelvan, D.; Buczkowski, H.; Banyard, A.C.

    2015-01-01

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  17. Peste des petits ruminants.

    PubMed

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants.

  18. Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography.

    PubMed

    Jovanović, Marko; Rakić, Tijana; Jančić-Stojanović, Biljana; Ivanović, Darko; Medenica, Mirjana

    2014-07-01

    Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.

  19. 12 CFR 226.25 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Record retention. 226.25 Section 226.25 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRUTH IN LENDING (REGULATION Z) Miscellaneous § 226.25 Record retention. (a) General rule. A creditor...

  20. 10 CFR 37.103 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Record retention. 37.103 Section 37.103 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL PROTECTION OF CATEGORY 1 AND CATEGORY 2 QUANTITIES OF RADIOACTIVE MATERIAL Records § 37.103 Record retention. Licensees shall maintain the records that are required by...

  1. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  2. Measuring Up: Benchmarking Graduate Retention. IES Report.

    ERIC Educational Resources Information Center

    Tyers, C.; Perryman, S.; Barber, L.

    Retention of college graduates by employers across the United Kingdom was examined. Data were collected through a survey of 362 organizations and interviews with 36 employers and their graduate employees. Most employers were unworried by their levels of graduate retention; two-thirds expected to keep new recruits for the foreseeable future. Rates…

  3. Novel Word Retention in Sequential Bilingual Children

    ERIC Educational Resources Information Center

    Kan, Pui Fong

    2014-01-01

    Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after…

  4. 76 FR 34010 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ...-AA43 DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 24 CFR Part 267 RIN 2501-AD53 Credit Risk Retention... a joint notice of proposed rulemaking for public comment to implement the credit risk retention... Reform and Consumer Protection Act (``Credit Risk NPR'' or ``proposed rule''). Due to the complexity...

  5. The Grade Retention/Social Promotion Debate.

    ERIC Educational Resources Information Center

    Lindelow, John

    1985-01-01

    This publication focuses on the retention/promotion debate regarding failing and low-achieving students. An introductory essay describes the inherent limitation in the research done on this issue--the impossibility of obtaining an appropriate control group--and suggests that the retention/promotion quandary can best be resolved by accommodating…

  6. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  7. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  8. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  9. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  10. Effective Teacher Retention Bonuses: Evidence From Tennessee

    ERIC Educational Resources Information Center

    Springer, Matthew G.; Swain, Walker A.; Rodriguez, Luis A.

    2016-01-01

    We report findings from a quasi-experimental evaluation of the recently implemented US$5,000 retention bonus program for effective teachers in Tennessee's Priority Schools. We estimate the impact of the program on teacher retention using a fuzzy regression discontinuity design by exploiting a discontinuity in the probability of treatment…

  11. Profile in Action: Linking Admission and Retention

    ERIC Educational Resources Information Center

    Cortes, Carla M.

    2013-01-01

    A profile-oriented retention strategy embraces the admission process as a powerful lever in improving retention and completion rates and recognizes that the student profile can be shaped by changes in admission policies or priorities--even within the current market position of the institution. In addition, the student body can be oriented toward…

  12. Emotional Intelligence and Nursing Student Retention

    ERIC Educational Resources Information Center

    Wilson, Victoria Jane

    2013-01-01

    The study examined the constructs of a Multi-Intelligence Model of Retention with four constructs: cognitive and emotional-social intelligence, student characteristics, and environmental factors. Data were obtained from sophomore students entering two diploma, nine associate, and five baccalaureate nursing programs. One year later, retention and…

  13. Faculty Personality: A Factor of Student Retention

    ERIC Educational Resources Information Center

    Shaw, Cassandra S.; Wu, Xiaodong; Irwin, Kathleen C.; Patrizi, L. A. Chad

    2016-01-01

    The purpose of this study was to determine the relationship between student retention and faculty personality as it was hypothesized that faculty personality has an effect on student retention. The methodology adopted for this study was quantitative and in two parts 1) using linear regression models to examine the impact or causality of faculty…

  14. Managing human resources to improve employee retention.

    PubMed

    Arnold, Edwin

    2005-01-01

    Managers face increased challenges as the demand for health care services increases while the supply of employees with the requisite skills continues to lag. Employee retention will become more important in the effort to service health care needs. Appropriate human resource management strategies and policies implemented effectively can significantly assist managers in dealing with the employee retention challenges ahead.

  15. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 354.73 Retention labels. An inspector may use such labels, devices, and methods as may be approved...

  16. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 354.73 Retention labels. An inspector may use such labels, devices, and methods as may be approved...

  17. Retention of New Teachers in California

    ERIC Educational Resources Information Center

    Reed, Deborah; Rueben, Kim S.; Barbour, Elisa

    2006-01-01

    In the continuing effort to raise the academic performance of public schools, improving teacher retention could be an important strategy for California. Keeping new teachers in the classroom could improve academic performance, because experienced teachers are, on average, more effective at raising student test scores. Better retention of teachers…

  18. Minority Teacher Recruitment and Retention Strategies

    ERIC Educational Resources Information Center

    Kearney-Gissendaner, Janet E.

    2010-01-01

    The tools and resources in this book help school leaders seamlessly incorporate minority teacher recruitment and retention programs into current human-resources activities. With details about exemplary minority teacher recruitment and retention programs, this book also showcases strategies for how to replicate such programs in your own school or…

  19. Using Enrollment Data to Predict Retention Rate

    ERIC Educational Resources Information Center

    Bingham, Melissa A.; Solverson, Natalie Walleser

    2016-01-01

    First- to second-year retention rates are one metric reported by colleges and universities to convey institutional success to a variety of external constituents. But how much of a retention rate is institutional inputs, and how much can be understood by examining student inputs? The authors utilize multi-year, multi-institutional data to examine…

  20. 5 CFR 9901.356 - Pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... retention. (b) Pay retention will be based on the employee's rate of base salary in effect immediately... under NSPS for the area, location, occupational group, or other class of positions involved; (ii) The remoteness of the area or location involved; (iii) The undesirability of the working conditions or the...

  1. 7 CFR 4280.136 - Minimum retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Minimum retention. 4280.136 Section 4280.136 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.136 Minimum retention. Minimum...

  2. Retention modelling in hydrophilic interaction chromatography.

    PubMed

    Euerby, Melvin R; Hulse, Jennifer; Petersson, Patrik; Vazhentsev, Andrey; Kassam, Karim

    2015-12-01

    The retention behaviour of acidic, basic and quaternary ammonium salts and polar neutral analytes has been evaluated on acidic, basic and neutral hydrophilic interaction chromatography (HILIC) stationary phases as a function of HILIC operating parameters such as MeCN content, buffer concentration, pH and temperature. Numerous empirical HILIC retention models (existing and newly developed ones) have been assessed for their ability to describe retention as a function of the HILIC operating parameters investigated. Retention models have been incorporated into a commercially available retention modelling programme (i.e. ACD/LC simulator) and their accuracy of retention prediction assessed. The applicability of HILIC modelling using these equations has been demonstrated in the two-dimensional isocratic (i.e. buffer concentration versus MeCN content modelling) and one-dimensional gradient separations for a range of analytes of differing physico-chemical properties on the three stationary phases. The accuracy of retention and peak width prediction was observed to be comparable to that reported in reversed-phase chromatography (RPC) retention modelling. Intriguingly, our results have confirmed that the use of gradient modelling to predict HILIC isocratic conditions and vice versa is not reliable. A relative ranking of the importance of the retention and selectivity of HILIC operating parameters has been determined using statistical approaches. For retention, the order of importance was observed to be organic content > stationary phase > temperature ≈ mobile phase pH (i.e. pH 3-6 which mainly effects the ionization of the analyte) ≈ buffer concentration. For selectivity, the nature of the stationary phase > mobile phase pH > buffer concentration > temperature > organic content.

  3. Quantifying colloid retention in partially saturated porous media

    NASA Astrophysics Data System (ADS)

    Zevi, Yuniati; Dathe, Annette; Gao, Bin; Richards, Brian K.; Steenhuis, Tammo S.

    2006-12-01

    The transport of colloid-contaminant complexes and colloid-sized pathogens through soil to groundwater is of concern. Visualization and quantification of pore-scale colloid behavior will enable better description and simulation of retention mechanisms at individual surfaces, in contrast to breakthrough curves which only provide an integrated signal. We tested two procedures for quantifying colloid movement and retention as observed in pore-scale image sequences. After initial testing with static images, three series of images of synthetic microbead suspensions passing through unsaturated sand were examined. The region procedure (implemented in ImageJ) and the Boolean procedure (implemented in KS400) yielded nearly identical results for initial test images and for total colloid-covered areas in three image series. Because of electronic noise resulting in pixel-level brightness fluctuations the Boolean procedure tended to underestimate attached colloid counts and conversely overestimate mobile colloid counts. The region procedure had a smaller overestimation error of attached colloids. Reliable quantification of colloid retention at pore scale can be used to improve current understanding on the transport mechanisms of colloids in unsaturated porous media. For example, attachment counts at individual air/water meniscus/solid interface were well described by Langmuir isotherms.

  4. Lubricant retention for liquid infused surfaces exposed to turbulent flow

    NASA Astrophysics Data System (ADS)

    Fu, Matthew; Hultmark, Marcus

    2015-11-01

    Liquid infused surfaces have been proposed as a robust alternative to traditional, air-filled superhydrophobic surfaces. The mobility of the liquid lubricant facilitates a surface slip with the outer turbulent shear flow. However, shear driven drainage in turbulent flow has been found to be a primary failure mechanism for such surfaces, resulting in loss of lubricant and the associated slip effect. A turbulent channel flow facility is used to characterize shear-driven drainage behavior of liquid infused micro-patterned surfaces. Micro-manufactured surfaces can be mounted flush in the channel and exposed to turbulent flows. The retention of fluorescent lubricants is monitored to characterize how surface geometry and lubricant properties affect the steady state retention length. Results are compared with theoretical predictions and experiments for lubricant retention in laminar microchannels, where the shear driven drainage is balanced by a Laplace pressure gradient, to determine the additional drainage induced by turbulent fluctuations. Supported under ONR Grants N00014-12-1-0875 and N00014-12-1-0962 (program manager Ki-Han Kim).

  5. Etude des Abondances de MG et de fe dans la Composante Stellaire des Disques des Galaxies Spirales

    NASA Astrophysics Data System (ADS)

    Beauchamp, Dominique

    Je presente ici une technique d'observation par imagerie des disques stellaires des galaxies spirales. Je tente, a l'aide d'un modele evolutif multiphase, de determiner les abondances de fer et de magnesium dans les disques. Dans ce but, je mesure les indices Mg2 et Fe5270 du systeme de Lick. Ces elements representent un choix judicieux d'indicateurs car ils sont formes par des supernovae de deux types differents ayant des durees de vie differentes. Le rapport d'abondances de ces deux elements est un indicateur du taux de formation des populations stellaires. Je decris, en premier lieu, les observations, la technique de mesure, ainsi que son application. J'analyse ensuite les indices mesures. A partir du modele multiphase, j'explore differents parametres physiques des spirales comme le taux de formation stellaire, l'evolution des abondances, les effets possibles de la presence de la barre, etc.

  6. Causes and implications of colloid and microorganism retention hysteresis.

    PubMed

    Bradford, Scott A; Kim, Hyunjung

    2012-09-01

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1 μm) and microorganisms (coliphage φX174 and E. coli D21g) under various transient solution chemistry conditions, and 360 μm Ottawa sand that was subject to different levels of cleaning, namely, a salt cleaning procedure that removed clay particles, and a salt+acid cleaning procedure that removed clay and reduced microscopic heterogeneities due to metal oxides and surface roughness. Comparison of results from the salt and salt+acid treated sand indicated that microscopic heterogeneity was a major contributor to colloid retention hysteresis. The influence of this heterogeneity increased with IS and decreasing colloid/microbe size on salt treated sand. These trends were not consistent with calculated mean interaction energies (the secondary minima), but could be explained by the size of the electrostatic zone of influence (ZOI) near microscopic heterogeneities. In particular, the depth of local minima in the interaction energy has been predicted to increase with a decrease in the ZOI when the colloid size and/or the Debye length decreased (IS increased). The adhesive interaction was therefore largely irreversible for smaller sized 0.1 μm CML colloids, whereas it was reversible for larger 1.1 μm CML colloids. Similarly, the larger E. coli D21g exhibited greater reversibility in retention than φX174. However, direct comparison of CML colloids and microbes was not possible due to differences in size, shape, and surface properties. Retention and release behavior of CML colloids on salt+acid treated sand was much more consistent with mean interaction energies due to reduction in microscopic heterogeneities.

  7. Average Soil Water Retention Curves Measured by Neutron Radiography

    SciTech Connect

    Cheng, Chu-Lin; Perfect, Edmund; Kang, Misun; Voisin, Sophie; Bilheux, Hassina Z; Horita, Juske; Hussey, Dan

    2011-01-01

    Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.

  8. Causes and implications of colloid and microorganism retention hysteresis

    NASA Astrophysics Data System (ADS)

    Bradford, Scott A.; Kim, Hyunjung

    2012-09-01

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1 μm) and microorganisms (coliphage φX174 and E. coli D21g) under various transient solution chemistry conditions, and 360 μm Ottawa sand that was subject to different levels of cleaning, namely, a salt cleaning procedure that removed clay particles, and a salt + acid cleaning procedure that removed clay and reduced microscopic heterogeneities due to metal oxides and surface roughness. Comparison of results from the salt and salt + acid treated sand indicated that microscopic heterogeneity was a major contributor to colloid retention hysteresis. The influence of this heterogeneity increased with IS and decreasing colloid/microbe size on salt treated sand. These trends were not consistent with calculated mean interaction energies (the secondary minima), but could be explained by the size of the electrostatic zone of influence (ZOI) near microscopic heterogeneities. In particular, the depth of local minima in the interaction energy has been predicted to increase with a decrease in the ZOI when the colloid size and/or the Debye length decreased (IS increased). The adhesive interaction was therefore largely irreversible for smaller sized 0.1 μm CML colloids, whereas it was reversible for larger 1.1 μm CML colloids. Similarly, the larger E. coli D21g exhibited greater reversibility in retention than φX174. However, direct comparison of CML colloids and microbes was not possible due to differences in size, shape, and surface properties. Retention and release behavior of CML colloids on salt + acid treated sand was much more consistent with mean interaction energies due to reduction in microscopic heterogeneities.

  9. Fractal processes in soil water retention

    SciTech Connect

    Tyler, S.W.; Wheatcraft, S.W. )

    1990-05-01

    The authors propose a physical conceptual model for soil texture and pore structure that is based on the concept of fractal geometry. The motivation for a fractal model of soil texture is that some particle size distributions in granular soils have already been shown to display self-similar scaling that is typical of fractal objects. Hence it is reasonable to expect that pore size distributions may also display fractal scaling properties. The paradigm that they used for the soil pore size distribution is the Sierpinski carpet, which is a fractal that contains self similar holes (or pores) over a wide range of scales. The authors evaluate the water retention properties of regular and random Sierpinski carpets and relate these properties directly to the Brooks and Corey (or Campbell) empirical water retention model. They relate the water retention curves directly to the fractal dimension of the Sierpinski carpet and show that the fractal dimension strongly controls the water retention properties of the Sierpinski carpet soil. Higher fractal dimensions are shown to mimic clay-type soils, with very slow dewatering characteristics and relatively low fractal dimensions are shown to mimic a sandy soil with relatively rapid dewatering characteristics. Their fractal model of soil water retention removes the empirical fitting parameters from the soil water retention models and provides paramters which are intrinsic to the nature of the fractal porous structure. The relative permeability functions of Burdine and Mualem are also shown to be fractal directly from fractal water retention results.

  10. Predictors of Calcium Retention in Adolescent Boys

    PubMed Central

    Hill, Kathleen M.; Braun, Michelle; Kern, Mark; Martin, Berdine R.; Navalta, James W.; Sedlock, Darlene A.; McCabe, Linda; McCabe, George P.; Peacock, Munro; Weaver, Connie M.

    2008-01-01

    Context: The relationship between calcium (Ca) intake and Ca retention in adolescent boys was recently reported. Objective: This study evaluated the influence of Ca intake, serum hormone levels, biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness on Ca retention in the same sample. Design: This study was a randomized, cross-over design that consisted of two 3-wk metabolic balance periods. Setting: The study took place on a university campus as a summer camp. Patients or Other Participants: A total of 31 American white boys (13–15 yr) participated in the study. Interventions: Each subject consumed a controlled diet with one of five high-low Ca intake pairs that ranged from 670-2003 mg/d, which was manipulated utilizing a fortified beverage. Main Outcome Measures: Ca retention was determined by Ca intake minus urinary and fecal Ca excretion during each balance period. Results: Ca intake explained 21.7% of the variability in Ca retention, and serum IGF-I concentration explained an additional 11.5%. Other serum hormone levels did not significantly add to the model. Biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness were not significant predictors of Ca retention in adolescent boys. Conclusions: IGF-I, a regulator of growth during puberty, is an important predictor of Ca retention in adolescent boys. However, dietary Ca intake is an even greater predictor of Ca retention during this period of growth. PMID:18840643

  11. Classification of 8 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    King, A.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; OâNeill, C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  12. Classification of 17 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Hoormann, J. K.; Asorey, J.; Carollo, D.; Moller, A.; Sharp, R.; Sommer, N. E.; Tucker, B. E.; Zhang, B.; Lidman, C.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Macaulay, E.; Nichol, R.; Childress, M.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Gupta, R.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Yuan, F.; Davis, T. M.; Hinton, S.; Muthukrishna, D.; Parkinson, D.; Lewis, G. F.; Uddin, S.; Kessler, R.; Lasker, J.; Scolnic, D.

    2016-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  13. Classification of 13 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Sommer, N.; Tucker, B. E.; Moller, A.; Zhang, B.; Macualay, E.; Lidman, C.; Gshwend, J.; Martini, P.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  14. Classification of 11 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Sharp, R.; Zhang, B.; Sommer, N. E.; Tucker, B. E.; Lidman, C.; Davis, T. M.; Asorey, J.; Mould, J.; Smith, M.; Macaulay, E.; Nichol, R.; Childress, M.; Prajs, S.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Gupta, R.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Carollo, D.; Moller, A.; Yuan, F.; Hinton, S.; Muthukrishna, D.; Parkinson, D.; Lewis, G. F.; Uddin, S.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.

    2017-01-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  15. Classification of 2 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    O'Neill, C. R.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Macaulay, E.; Nichol, R.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Gupta, R.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.

    2016-10-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  16. Classification of 3 DES Supernovae with OzDES

    NASA Astrophysics Data System (ADS)

    Moller, A.; Tucker, B. E.; Yuan, F.; Lewis, G.; Lidman, C.; Macaulay, E.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.

    2016-02-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  17. Classification of 20 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Davis, T. M.; Kim, A. G.; Macualay, E.; Lidman, C.; Sharp, R.; Tucker, B. E.; Yuan, F.; Zhang, B.; Lewis, G. F.; Sommer, N. E.; Martini, P.; Mould, J.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.

    2015-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  18. Classification of 14 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Tucker, B. E.; Sharp, R.; Yuan, F.; Zhang, B.; Lidman, C.; Davis, T. M.; Hinton, S.; Mould, J.; Smith, R. C.; Schubnell, M.; Kessler, R.; Scolnic, D.; Covarrubias, R. A.; Brout, D. J.; Fischer, J. A.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; D'Andrea, C.; Smith, M.; Sullivan, M.; Childress, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Castander, F. J.; Desai, S.; Paech, K.

    2015-10-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey. The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  19. Classification of 4 DES supernovae by OzDES

    NASA Astrophysics Data System (ADS)

    Glazebrook, K.; Amon, A.; Lidman, C.; Martini, P.; Tucker, B. E.; Yuan, F.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.

    2015-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  20. Classification of 6 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Lewis, G. F.; Mould, J.; Lidman, C.; Tucker, B. E.; Sharp, R.; Yuan, F.; Martini, P.; Kessler, R.; Scolnic, D.; Covarrubias, R. A.; Brout, D. J.; Fischer, J. A.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; D'Andrea, C.; Smith, M.; Sullivan, M.; Childress, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.

    2015-10-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  1. Classification of 15 DES supernovae by OzDES

    NASA Astrophysics Data System (ADS)

    Yuan, F.; Tucker, B. E.; Lidman, C.; Martini, P.; Gshwend, Julia; Moller, A.; Zhang, B.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.

    2015-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  2. Classification of 17 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Mudd, D.; Martini, P.; Lewis, G. F.; Moller, A.; Sharp, R. G.; Sommer, N. E.; Tucker, B. E.; Yuan, F.; Zhang, B.; Asorey, J.; Davis, T. M.; Hinton, S.; Muthukrishna, D.; Parkinson, D.; Carnero, A.; King, A.; Lidman, C.; Webb, S.; Uddin, S.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Macaulay, E.; Nichol, R.; Childress, M.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Gupta, R.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.

    2016-11-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  3. Application of a quantitative structure retention relationship approach for the prediction of the two-dimensional gas chromatography retention times of polycyclic aromatic sulfur heterocycle compounds.

    PubMed

    Gieleciak, Rafal; Hager, Darcy; Heshka, Nicole E

    2016-03-11

    Information on the sulfur classes present in petroleum is a key factor in determining the value of refined products and processing behavior in the refinery. A large part of the sulfur present is included in polycyclic aromatic sulfur heterocycles (PASHs), which in turn are difficult to desulfurize. Furthermore, some PASHs are potentially more mutagenic and carcinogenic than polycyclic aromatic hydrocarbons, PAHs. All of this calls for improved methods for the identification and quantification of individual sulfur species. Recent advances in analytical techniques such as comprehensive two-dimensional gas chromatography (GC×GC) have enabled the identification of many individual sulfur species. However, full identification of individual components, particularly in virgin oil fractions, is still out of reach as standards for numerous compounds are unavailable. In this work, a method for accurately predicting retention times in GC×GC using a QSRR (quantitative structure retention relationship) method was very helpful for the identification of individual sulfur compounds. Retention times for 89 saturated, aromatic, and polyaromatic sulfur-containing heterocyclic compounds were determined using two-dimensional gas chromatography. These retention data were correlated with molecular descriptors generated with CODESSA software. Two independent QSRR relationships were derived for the primary as well as the secondary retention characteristics. The predictive ability of the relationships was tested by using both independent sets of compounds and a cross-validation technique. When the corresponding chemical standards are unavailable, the equations developed for predicting retention times can be used to identify unknown chromatographic peaks by matching their retention times with those of sulfur compounds of known molecular structure.

  4. Online Mate-Retention Tactics on Facebook Are Associated With Relationship Aggression.

    PubMed

    Brem, Meagan J; Spiller, Laura C; Vandehey, Michael A

    2015-10-01

    A measure of Facebook-related mate-retention tactics was developed to investigate the relationship between online behaviors and intimate partner aggression. One hundred and seventy-seven young adults (65 men, 112 women) completed questionnaires that included measures of online and offline mate-retention tactics, Facebook jealousy, Facebook surveillance, and intimate partner violence. A factor analysis yielded four subscales for the Facebook Mate-Retention Tactic Inventory (FMRTI): Care and Affection, Jealousy and Surveillance, Possession Signals, and Punishment of Infidelity Threat. The FMRTI total scores were positively correlated with Facebook jealousy, Facebook surveillance, and use of offline mate-retention tactics. The Jealousy and Surveillance subscale uniquely predicted intimate partner psychological and physical aggression over and above existing measures. Facebook mate-retention tactics fully mediated the relation between Facebook jealousy and both intimate partner psychological and physical aggression. The current study provides preliminary evidence for conceptualizing Facebook as an environment for the use of mate-retention tactics that have real-life implications for intimate partner violence.

  5. Retention and leaching of nitrite by municipal solid waste incinerator bottom ash under the landfill circumstance.

    PubMed

    Yao, Jun; Kong, Qingna; Zhu, Huayue; Long, Yuyang; Shen, Dongsheng

    2015-01-01

    The retention and leaching of nitrite by municipal solid waste incinerator (MSWI) bottom ash could affect its migration in the landfill. In this study, the effect of the dosage of MSWI bottom ash as well as the variation of the landfill environmental parameters including pH, anions and organic matter on the nitrite retention and leaching behavior was investigated by batch experiments. The highest removal percentage (73.0%) of nitrite was observed when the dosage of MSWI bottom ash was 10 g L(-1) in 2 mg L(-1) nitrite solution. Further increase of the dosage would retard the retention, as the nitrite leaching from MSWI bottom ash was enhanced. The optimum retention of nitrite was observed when the pH was 5.0, while the leaching of nitrite showed a consistent reduction with the increase of pH. Besides, the presence of Cl(-), SO4(2)(-) and acetic acid could enhance the leaching of nitrite and mitigate the retention process. However, the retention of nitrite was enhanced by PO4(3)(-), which was probably due to the formation of the apatite, an active material for the adsorption of the nitrite. These results suggested that MSWI bottom ash could affect the migration of nitrite in the landfill, which was related to the variation of the landfill circumstance.

  6. Latina Voices of Des Moines.

    ERIC Educational Resources Information Center

    Taylor, P. Dawn

    This dissertation examines the lives of Hispanic women living in Des Moines and includes their views of problems and opportunities involved in living in that city. Interviews were conducted with 24 Latino women over the age of 17 who had been in the area for over 2 years. Findings indicate that learning to speak English was the single most…

  7. Evaluation of the Telecourse Program at Saddleback College: Student Retention and Academic Achievement.

    ERIC Educational Resources Information Center

    Smith, Jeanne

    A study was conducted at Saddleback College to evaluate the retention, achievement, and satisfaction of students enrolled in the college's telecourse program. The study sample included all telecourse and on-campus students enrolled in courses in American government, human behavior, music, and marine biology in spring 1983. Study methods, which…

  8. Third-Year College Retention and Transfer: Effects of Academic Performance, Motivation, and Social Connectedness

    ERIC Educational Resources Information Center

    Allen, Jeff; Robbins, Steven B.; Casillas, Alex; Oh, In-Sue

    2008-01-01

    We studied the effects of academic performance, motivation, and social connectedness on third-year retention, transfer, and dropout behavior. To accommodate the three outcome categories and nesting of data within institutions, we fit a hierarchical multinomial logistic regression path model with first-year academic performance as a mediating…

  9. [Electrochemical behavior of 3 magnetic alloys used for prosthetic retention].

    PubMed

    Pezzoli, M; Angelini, E; Zucchi, F; Re, G

    1989-06-01

    By means of potentiodynamic techniques the electrochemical behaviour of a ferromagnetic alloy Pd-Co and three types of caps (AISI 316 stainless steel, Pd, Ti) for permanent Sm-Co magnets has been investigated in artificial saliva and in Ringer's solution. In addition short-circuit measurements were performed on several couples Pd-Co/AISI 316, Ti, Pd caps. From our findings a good corrosion resistance of all the materials is evidenced in artificial saliva. In Ringer's solution, which is more aggressive, Pd-Co shows no tendency to passivity.

  10. Academic Dishonesty: Behaviors, Sanctions, and Retention of Adjudicated College Students

    ERIC Educational Resources Information Center

    Olafson, Lori; Schraw, Gregory; Kehrwald, Nicholas

    2014-01-01

    Academic dishonesty, also known as academic misconduct, includes a variety of actions such as plagiarism, cheating on tests using text messaging or concealed notes, exchanging work with other students, buying essays from students or on the Internet, and having other students write examinations (Diekhoff, LaBeff, Shinohara, & Yasukawa, 1999;…

  11. The Causal Effects of Grade Retention on Behavioral Outcomes

    ERIC Educational Resources Information Center

    Mariano, Lou; Martorell, Paco

    2015-01-01

    Requiring a failing student to repeat a grade is, of course, not a novel idea. The theory behind test-based promotion policies is that students who fail to demonstrate a sufficient understanding of their current grade's curriculum lack the prerequisite proficiency to fully engage in the following grade. This view recognizes the cumulative nature…

  12. Escitalopram-associated acute urinary retention.

    PubMed

    Trombetta, Dominick; Garrett, Kathleen; Harrison, Marissa

    2013-10-01

    New-onset urinary retention can typically be explained by the use of the routine normally suspected medications (e.g., anticholinergics, antihistamines). However, selective serotonin-reuptake inhibitors are not typically presumed as the cause of acute urinary retention (AUR). The following case describes the introduction of escitalopram in a patient and the subsequent development of AUR. Medical causes of urinary retention had been ruled out, and ipratropium was initially suspected to be the cause of urinary difficulties and was discontinued. However, the retention persisted four days after suspending the ipratropium. Normal micturition resumed only after stopping the escitalopram without further need for catheterization. Escitalopram may cause rare cases of AUR and may often times be overlooked possibly because of the paucity of reporting.

  13. Taking a Holistic Approach to Retention.

    ERIC Educational Resources Information Center

    Fields, Cheryl D.

    2002-01-01

    Describes how, at the University of Kansas, many students of color are excelling at a rate that has outpaced their peers. Campus officials credit the HAWK Link program and its comprehensive approach to retention. (EV)

  14. L'astronomie des Anciens

    NASA Astrophysics Data System (ADS)

    Nazé, Yaël

    2009-04-01

    Quelle que soit la civilisation à laquelle il appartient, l'être humain cherche dans le ciel des réponses aux questions qu'il se pose sur son origine, son avenir et sa finalité. Le premier mérite de ce livre est de nous rappeler que l'astronomie a commencé ainsi à travers les mythes célestes imaginés par les Anciens pour expliquer l'ordre du monde et la place qu'ils y occupaient. Mais les savoirs astronomiques passés étaient loin d'être négligeables et certainement pas limités aux seuls travaux des Grecs : c'est ce que l'auteur montre à travers une passionnante enquête, de Stonehenge à Gizeh en passant par Pékin et Mexico, fondée sur l'étude des monuments anciens et des sources écrites encore accessibles. Les tablettes mésopotamiennes, les annales chinoises, les chroniques médiévales, etc. sont en outre d'une singulière utilité pour les astronomes modernes : comment sinon remonter aux variations de la durée du jour au cours des siècles, ou percer la nature de l'explosion qui a frappé tant d'observateurs en 1054 ? Ce livre offre un voyage magnifiquement illustré à travers les âges, entre astronomie et archéologie.

  15. Magnetic denture retention systems: inexpensive and efficient.

    PubMed

    Gillings, B R

    1984-09-01

    A magnetic retention system has been used in more than 6000 complete and partial overdentures, sectional dentures and implant overdentures, with excellent clinical results and patient acceptability. For the overdenture application, decoronated, root-treated teeth are fitted with preformed or cast magnetisable alloy root elements, or 'keepers'. Following conventional denture construction, paired cobalt/samarium magnets in a special configuration are cured into the denture base so that with the denture inserted, the magnets grip the root elements with a retentive force of approximately 300 g per root. The paired magnet arrangement eliminates any external magnetic field and doubles the available retention. Magnetic retention has few of the problems encountered with other retention devices. It offers simplicity, low cost, self-adjustment, inherent stress-breaking, automatic repositioning after denture displacement, comparative freedom of lateral denture movement, reduces trauma to retained roots and eliminates the need for adjustment in service. For the sectional denture application, undesirable undercuts on the abutment teeth are used to provide passive, positive retention. The separate buccal and lingual sections are joined together by parallel pins fitting into matching tubes, assembly being maintained by magnetic attraction between a retention element in one section and a keeper in the other. Insertion and removal are more difficult than with a conventional denture but soft tissue coverage is minimal. There are no visible retainer arms and food traps are eliminated. Abutment tooth preparation is negligible, the laboratory procedures simple, and the treatment inexpensive and reversible. A clinical trial of magnetic overdenture retention in conjunction with osseointegrated titanium implants is now in progress. After 21 months acceptable clinical results have been obtained. An improved implant with an alumina core and a sintered hydroxyapatite coating is at present

  16. Effect of concentration, homogenization and stabilizing salts on heat stability and rheological properties of cow skim milk ultrafiltered retentate.

    PubMed

    Meena, Ganga Sahay; Singh, Ashish Kumar; Borad, Sanket; Panjagari, Narender Raju

    2016-11-01

    Ultrafiltration (UF) of skimmed milk altered the composition of UF retentate and decreased the heat stability. Heat stability further reduced upon its subsequent homogenization or diafiltration. Poor heat stability of UF retentate restricts its processing at elevated temperatures. Therefore, this study was aimed to investigate the effect of protein concentration, homogenization and addition of stabilizing salts on the heat stability and rheological properties of UF retentates. Changes in the heat stability of fivefold homogenized UF retentate (5× HUFR) was studied in the pH range of 6.1-7.0. Disodium phosphate and trisodium citrate significantly increased the heat coagulation time (HCT) from 1.45 min (pH 6.41) to 120 min (at pH 6.5, 6.6, 7.0) and 80 min (pH 6.6), respectively. Significant reduction in ζ-potential of UF retentates was observed with an increase in calcium and reduction in pH during UF process. Rheological behaviour of retentates above threefold concentration exhibited Herschel-Bulkley behavior with linear increase in flow behavior index (n). Changes in the viscosity of the homogenized retentates were measured at the respective pH of maximum heat stability as a function of temperature (20-80 °C). Promising approaches that might improve the heat stability, solubility and other functional properties of protein rich powders have been discussed in this article.

  17. Multistatic Surveillance and Reconnaissance: Sensor, Signals and Data Fusion (Surveillance et Reconnaissance Multistatiques : Fusion des capteurs, des signaux et des donnees)

    DTIC Science & Technology

    2009-04-01

    capteurs , des signaux et des données) Research and Technology Organisation (NATO) BP 25, F-92201 Neuilly-sur-Seine Cedex, France RTO-EN-SET-133...Multistatiques : Fusion des capteurs , des signaux et des données) The material in this publication was assembled to support a Lecture Series under the...Surveillance et Reconnaissance Multistatiques : Fusion des capteurs , des signaux et des données (RTO-EN-SET-133) Synthèse Les systèmes radar

  18. The influence of the structure of some aromatic heterocyclic derivatives on their retention in reversed-phase high-performance liquid chromatography

    NASA Astrophysics Data System (ADS)

    Kurbatova, S. V.; Saifutdinov, B. R.; Larionov, O. G.; Meshkovaya, V. V.

    2009-03-01

    The chromatographic behavior of aromatic heterocyclic derivatives in reversed-phase high-performance liquid chromatography was investigated. The retention characteristics of the substances under the conditions of chromatography with water-acetonitrile mobile phases (retention factors, relative retentions, distribution coefficients, Henry adsorption constants, differences in the differential molar energy of sorption, and Gibbs energies of sorption) were determined. It was shown that the chromatographic retention of the sorbates depended on their molecular structure. The influence of the nature of heteroatoms and their number on the sorption of heterocyclic compounds was discussed.

  19. Effect of dislocations on helium retention in deformed pure iron

    NASA Astrophysics Data System (ADS)

    Gong, Y. H.; Cao, X. Z.; Jin, S. X.; Lu, E. Y.; Hu, Y. C.; Zhu, T.; Kuang, P.; Xu, Q.; Wang, B. Y.

    2016-12-01

    The effects of dislocations created by deformation on helium retention in pure iron, including the helium atoms diffusion along the dislocation line and desorption from dislocation trapping sites, were investigated. The dislocation defect was introduced in specimens by cold-rolling, and then 5 keV helium ions were implanted into the deformed specimens. Slow positron beam technology and thermal desorption spectroscopy were used to investigate the evolution of dislocation defects and the desorption behavior of helium atoms under influence of dislocation. The behaviors of S-E, W-E and S-W plots indicate clearly that lots of helium atoms remain in the deformed specimen and helium atoms combining with dislocation change the distribution of electron density. The helium desorption plot indicates that dislocation accelerates helium desorption at 293 K-600 K and facilitates helium dissociation from HenVm (n/m = 1.8) cluster.

  20. Toward Improved Management of Officer Retention: A New Capability for Assessing Policy Options

    DTIC Science & Technology

    2014-01-01

    models are solely in the VBA code particular to each model . This design feature is intentional because it is typically much easier to understand... model of officer behavior, and we use the parameter estimates in a simulation model to help evaluate the effect that changes in compensation can...behavior of these officers can also change the aggregate retention of the population of officers at earlier or later years of their careers. The model

  1. Retention of U.S. Navy Surface Warfare Officers Before and After the Global War on Terror (GWOT)

    DTIC Science & Technology

    2012-03-01

    frequently and because of this, retention rates had decreased after GWOT. The increased OPTEMPO affected the retention behavior in a negative way . To...personnel and with officers in each service in the first six months of 2004. Their analysis focused on stress and intention to stay based on self-reports...The two measures of stress were higher-than-usual work stress and higher- than-usual personal stress . Four measures of intention to stay were used

  2. Active Control Technology for Enhanced Performance Operational Capabilities of Military Aircraft, Land Vehicles and Sea Vehicles (Technologies des systemes a commandes actives pour l’amelioration des performances operationnelles des aeronefs militaires, des vehicules terrestres et des vehicules maritimes)

    DTIC Science & Technology

    2001-06-01

    d’améliorer le comportement global des systèmes et des sous- systèmes. Il s’agit de matériaux intelligents, de technologies informatiques, de capteurs ...des servocommandes rapides et fiables, ainsi que des capteurs de fonctionnement fiable même dans des environnements défavorables, et en particulier...des sous-systèmes. Il s’agit de matériaux intelligents, de technologies de fabrication novatrices, de technologies informatiques, de capteurs et de

  3. Grade Retention: A Three Part Series. Policy Briefs. Grade Retention: A Flawed Education Strategy [and] Cost-Benefit Analysis of Grade Retention [and] Grade Retention: The Gap between Research and Practice

    ERIC Educational Resources Information Center

    Xia, Claire; Glennie, Elizabeth

    2005-01-01

    This document compiles a series of three policy briefs focused on the subject of grade retention. The first brief, "Grade Retention: A Flawed Education Strategy," suggests educators and policymakers caution the use of grade retention as a remedy for poor student performance. As concluded by the majority of past studies, grade retention is a failed…

  4. Synthesis, characterization and mechanism of polycarboxylate superplasticizer with slump retention capability

    NASA Astrophysics Data System (ADS)

    Li, Mengting; Wang, Yi; Jiang, Haidong; Zheng, Chunyang; Guo, Zhaolai

    2017-03-01

    Two kinds of slump-retaining polycarboxylate superplasticizer with different molecular structures were synthesized via maleic anhydride(MAH), polyethylene glycol monoallyl ether(APEG) and hydroxyethyl acrylate (HEA)/ethyl acrylate (EA) according to molecular structure design principle. The comprehensive performances of each slump-retaining polycarboxylate superplasticizer were analyzed and compared with that of different molecular structure. The Gel Permeation Chromatography (GPC), surface tension, zeta potential, adsorption behavior, cement paste fluidity and application performance in concrete were measured. And the slump retention mechanism was analyzed. The results show that the polycarboxylate superplaticizer with hydroxyethyl group prepared in this study has good dispersing performance and high slump retention capability for concrete.

  5. Retention of nucleic acids in ion-pair reversed-phase high-performance liquid chromatography depends not only on base composition but also on base sequence.

    PubMed

    Qiao, Jun-Qin; Liang, Chao; Wei, Lan-Chun; Cao, Zhao-Ming; Lian, Hong-Zhen

    2016-12-01

    The study on nucleic acid retention in ion-pair reversed-phase high-performance liquid chromatography mainly focuses on size-dependence, however, other factors influencing retention behaviors have not been comprehensively clarified up to date. In this present work, the retention behaviors of oligonucleotides and double-stranded DNAs were investigated on silica-based C18 stationary phase by ion-pair reversed-phase high-performance liquid chromatography. It is found that the retention of oligonucleotides was influenced by base composition and base sequence as well as size, and oligonucleotides prone to self-dimerization have weaker retention than those not prone to self-dimerization but with the same base composition. However, homo-oligonucleotides are suitable for the size-dependent separation as a special case of oligonucleotides. For double-stranded DNAs, the retention is also influenced by base composition and base sequence, as well as size. This may be attributed to the interaction of exposed bases in major or minor grooves with the hydrophobic alky chains of stationary phase. In addition, no specific influence of guanine and cytosine content was confirmed on retention of double-stranded DNAs. Notably, the space effect resulted from the stereostructure of nucleic acids also influences the retention behavior in ion-pair reversed-phase high-performance liquid chromatography.

  6. Retention prediction of low molecular weight anions in ion chromatography based on quantitative structure-retention relationships applied to the linear solvent strength model.

    PubMed

    Park, Soo Hyun; Haddad, Paul R; Talebi, Mohammad; Tyteca, Eva; Amos, Ruth I J; Szucs, Roman; Dolan, John W; Pohl, Christopher A

    2017-02-24

    Quantitative Structure-Retention Relationships (QSRRs) represent a popular technique to predict the retention times of analytes, based on molecular descriptors encoding the chemical structures of the analytes. The linear solvent strength (LSS) model relating the retention factor, k to the eluent concentration (log k=a-blog [eluent]), is a well-known and accurate retention model in ion chromatography (IC). In this work, QSRRs for inorganic and small organic anions were used to predict the regression parameters a and b in the LSS model (and hence retention times) for these analytes under a wide range of eluent conditions, based solely on their chemical structures. This approach was performed on retention data of inorganic and small organic anions from the "Virtual Column" software (Thermo Fisher Scientific). These retention data were recalibrated via a "porting" methodology on three columns (AS20, AS19, and AS11HC), prior to the QSRR modeling. This provided retention data more applicable on recently produced columns which may exhibit changes of column behavior due to batch-to-batch variability. Molecular descriptors for the analytes were calculated with Dragon software using the geometry-optimized molecular structures, employing the AM1 semi-empirical method. An optimal subset of molecular descriptors was then selected using an evolutionary algorithm (EA). Finally, the QSRR models were generated by multiple linear regression (MLR). As a result, six QSRR models with good predictive performance were successfully derived for a- and b-values on three columns (R(2)>0.98 and RMSE<0.11). External validation showed the possibility of using the developed QSRR models as predictive tools in IC (Qext(F3)(2)>0.7 and RMSEP<0.4). Moreover, it was demonstrated that the obtained QSRR models for the a- and b-values can predict the retention times for new analytes with good accuracy and predictability (R(2) of 0.98, RMSE of 0.89min, Qext(F3)(2) of 0.96 and RMSEP of 1.18min).

  7. Retention in care and medication adherence: current challenges to antiretroviral therapy success.

    PubMed

    Holtzman, Carol W; Brady, Kathleen A; Yehia, Baligh R

    2015-04-01

    Health behaviors such as retention in HIV medical care and adherence to antiretroviral therapy (ART) pose major challenges to reducing new HIV infections, addressing health disparities, and improving health outcomes. Andersen's Behavioral Model of Health Service Use provides a conceptual framework for understanding how patient and environmental factors affect health behaviors and outcomes, which can inform the design of intervention strategies. Factors affecting retention and adherence among persons with HIV include patient predisposing factors (e.g., mental illness, substance abuse), patient-enabling factors (e.g., social support, reminder strategies, medication characteristics, transportation, housing, insurance), and healthcare environment factors (e.g., pharmacy services, clinic experiences, provider characteristics). Evidence-based recommendations for improving retention and adherence include (1) systematic monitoring of clinic attendance and ART adherence; (2) use of peer or paraprofessional navigators to re-engage patients in care and help them remain in care; (3) optimization of ART regimens and pharmaceutical supply chain management systems; (4) provision of reminder devices and tools; (5) general education and counseling; (6) engagement of peer, family, and community support groups; (7) case management; and (8) targeting patients with substance abuse and mental illness. Further research is needed on effective monitoring strategies and interventions that focus on improving retention and adherence, with specific attention to the healthcare environment.

  8. Retention time variability as a mechanism for animal mediated long-distance dispersal.

    PubMed

    Guttal, Vishwesha; Bartumeus, Frederic; Hartvigsen, Gregg; Nevai, Andrew L

    2011-01-01

    Long-distance dispersal (LDD) events, although rare for most plant species, can strongly influence population and community dynamics. Animals function as a key biotic vector of seeds and thus, a mechanistic and quantitative understanding of how individual animal behaviors scale to dispersal patterns at different spatial scales is a question of critical importance from both basic and applied perspectives. Using a diffusion-theory based analytical approach for a wide range of animal movement and seed transportation patterns, we show that the scale (a measure of local dispersal) of the seed dispersal kernel increases with the organisms' rate of movement and mean seed retention time. We reveal that variations in seed retention time is a key determinant of various measures of LDD such as kurtosis (or shape) of the kernel, thinkness of tails and the absolute number of seeds falling beyond a threshold distance. Using empirical data sets of frugivores, we illustrate the importance of variability in retention times for predicting the key disperser species that influence LDD. Our study makes testable predictions linking animal movement behaviors and gut retention times to dispersal patterns and, more generally, highlights the potential importance of animal behavioral variability for the LDD of seeds.

  9. Information Warfare Officer Retention: Using a Capabilities-based Assessment to Solve Retention Issues

    DTIC Science & Technology

    2009-12-01

    39 1. Web -based Surveys............................................................... 39 2. Choice-based Conjoint... CONTACT E-MAILS .......................... 179 APPENDIX E. IW RETENTION SURVEY QUESTION 3 OPTIONS..................... 183 APPENDIX F. IW RETENTION...30 Table 6. Web -Based Survey Positives and Negatives (After Denmond, Johnson, Lewis

  10. Considering Student Retention as a Complex System: A Possible Way forward for Enhancing Student Retention

    ERIC Educational Resources Information Center

    Forsman, Jonas; van den Bogaard, Maartje; Linder, Cedric; Fraser, Duncan

    2015-01-01

    This study uses multilayer minimum spanning tree analysis to develop a model for student retention from a complex system perspective, using data obtained from first-year engineering students at a large well-regarded institution in the European Union. The results show that the elements of the system of student retention are related to one another…

  11. Calculation of retention time tolerance windows with absolute confidence from shared liquid chromatographic retention data.

    PubMed

    Boswell, Paul G; Abate-Pella, Daniel; Hewitt, Joshua T

    2015-09-18

    Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user's system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called "retention projection" was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously.

  12. Nursing Student Retention in Associate Degree Nursing Programs Utilizing a Retention Specialist

    ERIC Educational Resources Information Center

    Schrum, Ronna A.

    2014-01-01

    The purpose of this study was to examine specific variables associated with nursing student retention in Associate Degree Nursing (ADN) Programs. Jeffreys (2004) Nursing Undergraduate Retention and Success (NURS) conceptual model provided the framework for this descriptive correlational study. One hundred sixty eight pre-licensure associate degree…

  13. Signature spectrale des grains interstellaires.

    NASA Astrophysics Data System (ADS)

    Léger, A.

    Notre connaissance de la nature des grains interstellaires reposait sur un nombre très restreint de signatures spectrales dans la courbe d'extinction du milieu interstellaire. Une information considérable est contenue dans les 40 bandes interstellaires diffuses dans le visible, mais reste inexploitée. L'interprétation récente des cinq bandes IR en émission, en terme de molécules d'hydrocarbures aromatiques polycycliques, est développée. Elle permet l'utilisation d'une information spectroscopique comparable, à elle seule, à ce sur quoi était basée jusqu'alors notre connaissance de la matière interstellaire condensée. Différentes implications de cette mise en évidence sont proposées.

  14. Employee retention: a customer service approach.

    PubMed

    Gerson, Richard F

    2002-01-01

    Employee retention is a huge problem. There are staff shortages in radiology because not enough people are entering the profession; too many people are leaving the profession for retirement, higher-paying jobs or jobs with less stress; and there are not enough opportunities for career advancement. Staff shortages are exacerbated by difficulty in retaining people who enter the profession. While much work has been focused on recruitment and getting more people "in the front door," I suggest that the bulk of future efforts be focused on employee retention and "closing the back door." Employee retention must be an ongoing process, not a program. Approaches to employee retention that focus on external things, i.e., things that the company can do to or for the employee, generally are not successful. The truth is that employee retention processes must focus on what the employee gets out of the job. The process must be a benefits-based approach that helps employees answer the question, "What's in it for me?" The retention processes must be ongoing and integrated into the daily culture of the company. The best way to keep your employees is to treat them like customers. Customer service works for external customers. We treat them nicely. We work to satisfy them. We help them achieve their goals. Why not do the same for our employees? If positive customer service policies and practices can satisfy and keep external customers, why not adapt these policies and practices for employees? And, there is a service/satisfaction link between employee retention and higher levels of customer satisfaction. Customers prefer dealing with the same employees over and over again. Employee turnover destroys a customer's confidence in the company. Just like a customer does not want to have to "train and educate" a new provider, they do not want to do the same for your "revolving door" employees. So, the key is to keep employees so they in turn will help you keep your customers. Because the

  15. Original research: nurse-physician relationships: impact on nurse satisfaction and retention.

    PubMed

    Rosenstein, Alan H

    2002-06-01

    The worsening state of the nation's nursing shortage has drawn attention to the need for more effective ways to recruit and retain nurses. For this reason, VHA West Coast (a regional division of VHA, Inc., a national network of community-owned hospitals and health care systems) conducted the targeting nurses, physicians, and executives in a large network of hospitals. VHA designed the survey to assess how these disparate groups viewed nurse-physician relationships, disruptive physician behavior, the institutional response to such behavior, and how such behavior affected nurse satisfaction, morale, and retention. An analysis of the first 1,200 responses from nurses, physicians, and hospital executives suggests that daily interactions between nurses and physicians strongly influence nurses' morale. All respondents were very concerned with the significance of nurse-physician relationships and the atmosphere they create. And although all respondents saw a direct link between disruptive physician behavior and nurse satisfaction and retention, the groups differed in their beliefs about responsibility, barriers to progress, and potential solutions. The findings suggest that the quality of nurse-physician relationships must be addressed as facilities seek to improve nurse recruitment and retention. A survey shows that relations with physicians greatly affect nurses' job satisfaction and morale. Disruptive behavior on the part of physicians is a chief issue.

  16. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention.

  17. Use of mucolytics to enhance magnetic particle retention at a model airway surface

    NASA Astrophysics Data System (ADS)

    Ally, Javed; Roa, Wilson; Amirfazli, A.

    A previous study has shown that retention of magnetic particles at a model airway surface requires prohibitively strong magnetic fields. As mucus viscoelasticity is the most significant factor contributing to clearance of magnetic particles from the airway surface, mucolytics are considered in this study to reduce mucus viscoelasticity and enable particle retention with moderate strength magnetic fields. The excised frog palate model was used to simulate the airway surface. Two mucolytics, N-acetylcysteine (NAC) and dextran sulfate (DS) were tested. NAC was found to enable retention at moderate field values (148 mT with a gradient of 10.2 T/m), whereas DS was found to be effective only for sufficiently large particle concentrations at the airway surface. The possible mechanisms for the observed behavior with different mucolytics are also discussed based on aggregate formation and the loading of cilia.

  18. Safeguards Workforce Repatriation, Retention and Utilization

    SciTech Connect

    Gallucci, Nicholas; Poe, Sarah

    2015-10-01

    Brookhaven National Laboratory was tasked by NA-241 to assess the transition of former IAEA employees back to the United States, investigating the rate of retention and overall smoothness of the repatriation process among returning safeguards professionals. Upon conducting several phone interviews, study authors found that the repatriation process went smoothly for the vast majority and that workforce retention was high. However, several respondents expressed irritation over the minimal extent to which their safeguards expertise had been leveraged in their current positions. This sentiment was pervasive enough to prompt a follow-on study focusing on questions relating to the utilization rather than the retention of safeguards professionals. A second, web-based survey was conducted, soliciting responses from a larger sample pool. Results suggest that the safeguards workforce may be oversaturated, and that young professionals returning to the United States from Agency positions may soon encounter difficulties finding jobs in the field.

  19. A Practical Methodology to Measure Unbiased Gas Chromatographic Retention Factor vs. Temperature Relationships

    PubMed Central

    Peng, Baijie; Kuo, Mei-Yi; Yang, Panhia; Hewitt, Joshua T.; Boswell, Paul G.

    2014-01-01

    Compound identification continues to be a major challenge. Gas chromatography-mass spectrometry (GC-MS) is a primary tool used for this purpose, but the GC retention information it provides is underutilized because existing retention databases are experimentally restrictive and unreliable. A methodology called “retention projection” has the potential to overcome these limitations, but it requires the retention factor (k) vs. T relationship of a compound to calculate its retention time. Direct methods of measuring k vs. T relationships from a series of isothermal runs are tedious and time-consuming. Instead, a series of temperature programs can be used to quickly measure the k vs. T relationships, but they are generally not as accurate when measured this way because they are strongly biased by non-ideal behavior of the GC system in each of the runs. In this work, we overcome that problem by using the retention times of 25 n-alkanes to back-calculate the effective temperature profile and hold-up time vs. T profiles produced in each of six temperature programs. When the profiles were measured this way and taken into account, the k vs. T relationships measured from each of two different GC-MS instruments were nearly as accurate as the ones measured isothermally, showing less than 2-fold more error. Furthermore, temperature-programmed retention times calculated in five other labs from the new k vs. T relationships had the same distribution of error as when they were calculated from k vs. T relationships measured isothermally. Free software was developed to make the methodology easy to use. The new methodology potentially provides a relatively fast and easy way to measure unbiased k vs. T relationships. PMID:25496658

  20. Critical role of surface roughness on colloid retention and release in porous media.

    PubMed

    Torkzaban, Saeed; Bradford, Scott A

    2016-01-01

    This paper examines the critical role of surface roughness (both nano- and micro-scale) on the processes of colloid retention and release in porous media under steady-state and transient chemical conditions. Nanoscale surface roughness (NSR) in the order of a few nanometers, which is common on natural solid surfaces, was incorporated into extended-DLVO calculations to quantify the magnitudes of interaction energy parameters (e.g. the energy barrier to attachment, ΔΦa , and detachment, ΔΦd , from a primary minimum). This information was subsequently used to explain the behavior of colloid retention and release in column and batch experiments under different ionic strength (IS) and pH conditions. Results demonstrated that the density and height of NSR significantly influenced the interaction energy parameters and consequently the extent and kinetics of colloid retention and release. In particular, values of ΔΦa and ΔΦd significantly decreased in the presence of NSR. Therefore, consistent with findings of column experiments, colloid retention in the primary minimum was predicted to occur at some specific locations on the sand surface, even at low IS conditions. However, NSR yielded a much weaker primary minimum interaction compared with that of smooth surfaces. Colloid release from primary minima upon decreasing IS and increasing pH was attributed to the impact of NSR on the values of ΔΦd . Pronounced differences in the amount of colloid retention in batch and column experiments indicated that primary minimum interactions were weak even at high IS conditions. Negligible colloid retention in batch experiments was attributed to hydrodynamic torques overcoming adhesive torques, whereas significant colloid retention in column experiments was attributed to nano- and micro-scale roughness which would dramatically alter the lever arms associated with hydrodynamic and adhesive torques.

  1. Transport quantique dans des nanostructures

    NASA Astrophysics Data System (ADS)

    Naud, C.

    2002-09-01

    structure des oscillations de conductance en fonction du flux du champ magnétique de période h/e dont l'amplitude est beaucoup plus importante que celle mesurée sur un réseau carré de même dimension. Cette différence constitue une signature d'un effet de localisation induit par le champ magnétique sur la topologie mathcal{T}3. Pour des valeurs spécifiques du champ magnétique, du fait des interférences destructives Aharonov-Bohm, la propagation des fonctions d'ondes est limitée à un ensemble fini de cellule du réseau appelé cage. De la dépendance en température des oscillations de période h/e mesurées sur le réseau mathcal{T}3 nous avons tiré une longueur caractéristique qui peut être rattachée au périmètre des cages. Un phénomène inattendu fut l'observation, pour des champs magnétiques plus importants, d'un doublement de fréquence des oscillations. Ces oscillations de période h/2e pouvant avoir une amplitude supérieure aux oscillations de période h/e, une interprétation en terme d'harmonique n'est pas possible. Enfin, l'influence de la largeur électrique des fils constituant le réseau et donc celle du nombre de canaux par brin a été étudiée en réalisant des grilles électrostatique. Les variations de l'amplitude des signaux en h/e et h/2e en fonction de la tension de grille ont été mesurés.

  2. USAR Nurse Referral and Retention Program.

    PubMed

    Foley, J E; Foley, B J

    1992-09-01

    In 1987, the 804th Hospital Center made alleviating the shortfall of registered nurses in the Command a priority. The Command had only 79% of its registered nurse positions filled at the time. Using the recruitment strategies of an employee referral program and a mailing list, the Command reached 100% fill in 2 years and maintained those gains for an additional year. Retention strategies were also implemented which lowered the attrition rate. This paper describes the Army Nurse Referral and Retention Program developed and implemented at the 804th Hospital Center that relieved the shortfall of registered nurses in the United States Army Reserve in New England.

  3. JT8D engine performance retention

    NASA Technical Reports Server (NTRS)

    James, A. D.; Weisel, D. R.

    1981-01-01

    The attractive performance retention characteristics of the JT8D engine are described. Because of its moderate bypass ratio and turbine temperature, and stiff structural design, the performance retention versus flight cycles of the JT8D engine sets a standard that is difficult for other engines to equal. In addition, the significant benefits of refurbishment of the JT8D engine are presented. Cold section refurbishment offers thrust specific fuel consumption improvements of up to 2 percent and payback in less than a year, making a very attractive investment option for the airlines.

  4. Nitrogen Saturation in Highly Retentive Watersheds?

    NASA Astrophysics Data System (ADS)

    Daley, M. L.; McDowell, W. H.

    2009-12-01

    Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

  5. Mentoring--a staff retention tool.

    PubMed

    Kanaskie, Mary Louise

    2006-01-01

    Staff retention presents a common challenge for hospitals nationwide. Mentorship programs have been explored as one method of creating environments that promote staff retention. Successful achievement of nurse competencies identified in the Synergy Model for Patient Care can best be achieved in an environment that encourages and facilitates mentoring. Mentoring relationships in critical care provide the ongoing interactions, coaching, teaching, and role modeling to facilitate nurses' progression along this continuum. Mentoring relationships offer support and professional development for nurses at all levels within an organization as well as an optimistic outlook for the nursing profession.

  6. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    NASA Astrophysics Data System (ADS)

    Amrani, Salah

    La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

  7. Examining the effect of the Life Enhancement Treatment for Substance Use (LETS ACT) on residential substance abuse treatment retention.

    PubMed

    Magidson, Jessica F; Gorka, Stephanie M; MacPherson, Laura; Hopko, Derek R; Blanco, Carlos; Lejuez, C W; Daughters, Stacey B

    2011-06-01

    Effective, parsimonious behavioral interventions that target reinforcement are needed for substance users with depression to improve mood as well as treatment retention. The Life Enhancement Treatment for Substance Use (LETS ACT; Daughters et al., 2008) is a behavioral activation-based approach tailored to increase levels of positive reinforcement among depressed substance users while in substance abuse treatment. The current study tested the efficacy of LETS ACT compared to a contact-time matched control condition, supportive counseling (SC), examining effects on depressed mood, substance abuse treatment retention, and behavioral activation outcomes. Fifty-eight adult substance users in residential substance abuse treatment presenting with depressive symptoms (BDI≥12) were randomly assigned to LETS ACT or SC. Assessments were administered at pre- and post-treatment and included assessment of DSM-IV psychiatric diagnoses, depression severity, treatment motivation, overall activation, environmental reward, and substance abuse treatment retention. Patients in LETS ACT had significantly higher rates of substance abuse treatment retention and significantly greater increases in activation on the Behavioral Activation for Depression Scale (BADS) compared to those in SC. Both groups had decreased depression severity at post-treatment, although the group by time interaction was not significant. This study was the first to compare LETS ACT to a contact-time matched control treatment to evaluate effects on substance abuse treatment retention and two distinct measures of behavioral activation: overall activation and environmental reward. Findings suggest preliminary support for the feasibility, tolerability, and efficacy of a brief behavioral activation-based protocol that may be particularly useful to improve substance abuse treatment retention.

  8. Application of hydrophilic interaction chromatography retention coefficients for predicting peptide elution with TFA and methanesulfonic acid ion-pairing reagents.

    PubMed

    Wujcik, Chad E; Tweed, Joseph; Kadar, Eugene P

    2010-03-01

    Hydrophilic retention coefficients for 17 peptides were calculated based on retention coefficients previously published for TSKgel silica-60 and were compared with the experimental elution profile on a Waters Atlantis HILIC silica column using TFA and methanesulfonic acid (MSA) as ion-pairing reagents. Relative peptide retention could be accurately determined with both counter-ions. Peptide retention and chromatographic behavior were influenced by the percent acid modifier used with increases in both retention and peak symmetry observed at increasing modifier concentrations. The enhancement of net peptide polarity through MSA pairing shifted retention out by nearly five-fold for the earliest eluting peptide, compared with TFA. Despite improvements in retention and efficiency (N(eff)) for MSA over TFA, a consistent reduction in calculated selectivity (alpha) was observed. This result is believed to be attributed to the stronger polar contribution of MSA masking and diminishing the underlying influence of the amino acid residues of each associated peptide. Finally, post-column infusion of propionic acid and acetic acid was evaluated for their potential to recover signal intensity for TFA and MSA counter-ions for LC-ESI-MS applications. Acetic acid generally yielded more substantial signal improvements over propionic acid on the TFA system while minimal benefits and some further reductions were noted with MSA.

  9. A second order kinetic approach for modeling solute retention and transport in soils

    NASA Astrophysics Data System (ADS)

    Selim, H. M.; Amacher, M. C.

    1988-12-01

    We present a second-order kinetic approach for the description of solute retention during transport in soils. The basis for this approach is that it accounts for the sites on the soil matrix which are accessible for retention of the reactive solutes in solution. This approach was incorporated with the fully kinetic two-site model where the difference between the characteristics of the two types of sites is based on the rate of kinetic retention reactions. We also assume that the retention mechanisms are site-specific, e.g., the sorbed phase on type 1 sites may be characteristically different in their energy of reaction and/or the solute species from that on type 2 sites. The second-order two-site (SOTS) model was capable of describing the kinetic retention behavior of Cr(VI) batch data for Olivier, Windsor, and Cecil soils. Using independently measured parameters, the SOTS model was successful in predicting experimental Cr breakthrough curves (BTC's). The proposed second-order approach was also extended to the diffusion controlled mobile-immobile or two-region (SOMIM) model. The use of estimated parameters (e.g., the mobile water fraction and mass transfer coefficients) for the SOMIM model did not provide improved predictions of Cr BTC's in comparison to the SOTS model. The failure of the mobile-immobile model was attributed to the lack of nonequilibrium conditions for the two regions in these soils.

  10. Effects of polymer retention on dynamics of single phase flow

    NASA Astrophysics Data System (ADS)

    Parsa, Shima; Weitz, David

    2014-11-01

    We study the effect of adsorption of polymer solution on dynamics of a single phase flow in a model porous medium. We use confocal microscopy to fully visualize the flow of fluid in 3D micromodel of porous media. Polymer flooding is known to be an effective method for enhanced oil recovery. However, the physical mechanism is not clearly understood. We study the effect of polymer retention on the dynamics of single phase flow using particle image velocimetery. The distribution of velocities in the medium changes greatly after flow of high concentrations of polymer through the medium. Comparing the magnitude of velocities before and after the polymer flow, we observe reduction of accessible pores to the fluid at similar injection rates. Independent measurement of the permeability of the medium confirms the decrease in the porosity. Measurements of the retention of polymer in porous media shows a weak dependence on the hydrodynamic radius of the polymer. In these experiments, the viscoelastic behavior of the polymer is isolated from velocity measurements.

  11. Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

    SciTech Connect

    Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

    2010-04-15

    Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had {sup 125}I and 638 patients had {sup 103}Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline alpha-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm{sup 3}, 25-45 cm{sup 3}, <25 cm{sup 3}; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline alpha-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

  12. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  13. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  14. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  15. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  16. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  17. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  18. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  19. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 28 2011-07-01 2011-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  20. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  1. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  2. Tallahassee Community College Retention Study. Final Report.

    ERIC Educational Resources Information Center

    Johnston, Archie B.

    A retention study was conducted at Tallahassee Community College (TCC) to determine reasons student withdrew from TCC prior to meeting their educational objectives. The survey population consisted of all students, apart from graduates and those who had been academically suspended, who were enrolled in winter 1981 but had not returned by winter…

  3. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2012-01-01 2012-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  4. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2013-01-01 2013-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  5. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2014-01-01 2014-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  6. 12 CFR 1026.25 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 9 2014-01-01 2014-01-01 false Record retention. 1026.25 Section 1026.25 Banks... under § 1026.19(e) and (f)) for two years after the date disclosures are required to be made or action... inspect its relevant records for compliance. (c) Records related to certain requirements for...

  7. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  8. Does Retention Help? Perspectives after Three Years.

    ERIC Educational Resources Information Center

    Schuyler, Nancy Baenen

    The Austin Independent School District Office of Research and Evaluation (AISD-ORE) has recently completed a three year study of the effects of retention on elementary students. As in other studies comparing the academic achievement of elementary retainees and similar students not retained, findings indicated that promoted students generally show…

  9. The Literature on Social Promotion versus Retention.

    ERIC Educational Resources Information Center

    Southwest Educational Development Lab., Austin, TX.

    This general review of the relative merits of social promotion and retention examines research on the benefits of each, describes current strategies for resolving the policy dilemma involved, and considers issues raised by abolishing social promotion and establishing remedial programs. A summary of the history of the widespread adoption of the…

  10. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF... requirements of this section, DHS will, after coordination with OPM, issue implementing directives...

  11. Relationship of Personality Traits to Student Retention

    ERIC Educational Resources Information Center

    Liang, John Paul

    2010-01-01

    Carl Jung's theory of psychological types has been the basis for the development of personality categorization, including tests such as Myers-Briggs Type Indicator (MBTI). This study analyzed the extent of the relationship between MBTI and Tinto (1993) retention factors that influence Oriental medicine students' choice of staying or dropping out…

  12. Healthcare Learning Community and Student Retention

    ERIC Educational Resources Information Center

    Johnson, Sherryl W.

    2014-01-01

    Teaching, learning, and retention processes have evolved historically to include multifaceted techniques beyond the traditional lecture. This article presents related results of a study using a healthcare learning community in a southwest Georgia university. The value of novel techniques and tools in promoting student learning and retention…

  13. Retention--A Pseudo-Problem?

    ERIC Educational Resources Information Center

    Geis, George L.

    1999-01-01

    Discusses retention of learning; training methods; maintenance issues; the effect of punishment; reinforcement; the performance environment; transfer of training; forgetting; implications for designers of instructional materials or designers of training programs; and the division between training and on-the-job performance. (LRW)

  14. An Examination of Master's Student Retention & Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Mathies, Charles

    2011-01-01

    This study was conducted at a research-extensive public university in the southeastern United States. It examined the retention and completion of master's degree students across numerous disciplines. Results were derived from a series of descriptive statistics, T-tests, and a series of binary logistic regression models. The findings from binary…

  15. 49 CFR 236.1037 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Records retention. 236.1037 Section 236.1037...; (3) An Operations and Maintenance Manual, pursuant to § 236.1039; and (4) Training and testing... designated office training records required under § 236.1039(b). (d) After the PTC system is placed...

  16. Long-Term Retention of Conditioned Attitudes.

    ERIC Educational Resources Information Center

    Staats, Arthur W.; And Others

    The extent to which semantic differential ratings of trigrams remain consistent over a four-week retention period following pairing with positive or negative attitudinal words was determined. The trigrams initially served as stimulus items in a paired associate list consisting of both positive and negative evaluative response terms; and rating and…

  17. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Record retention. 946.10 Section 946.10 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10...

  18. Texas Teacher Recruitment and Retention Study.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This report on teacher recruitment and retention in Texas identifies and analyzes programs offered by higher education institutions, school districts, regional education service centers, and other organizations that address the teacher shortage in Texas. The study was undertaken with the understanding that teacher compensation issues are pervasive…

  19. Effects of Emotional Intelligence on Teacher Retention

    ERIC Educational Resources Information Center

    Gerald, Grant Ronald

    2010-01-01

    This mixed methods, explanatory design study focused on determining if the emotional intelligence of principals affects the retention of new teachers. In phase one, a non-random cluster sample of 138 public school principals in the state of Louisiana was surveyed using a quantitative instrument. A Factor Analysis, Analysis of Variance (ANOVA), and…

  20. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  1. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  2. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  3. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  4. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  5. Employee Retention: A Challenge of the Nineties.

    ERIC Educational Resources Information Center

    Zeiss, Tony

    1990-01-01

    Considers ways in which community colleges can help employers implement programs to improve the work environment and retain trained workers. Presents a model for employee retention that has worked effectively in Pueblo, Colorado. Describes Pueblo Community College's cooperative program with the Wats Marketing Group to help reduce employee…

  6. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  7. High temperature ceramic composition for hydrogen retention

    DOEpatents

    Webb, R.W.

    1974-01-01

    A ceramic coating for H retention in fuel elements is described. The coating has relatively low thermal neutron cross section, is not readily reduced by H at 1500 deg F, is adherent to the fuel element base metal, and is stable at reactor operating temperatures. (JRD)

  8. COMPARTMENTAL MODEL OF NITRATE RETENTION IN STREAMS

    EPA Science Inventory

    A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first order reaction terms to represent nitrate uptake in the free stream, and denitrifica...

  9. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  10. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  11. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  12. 1978-79 Recruitment & Retention Program.

    ERIC Educational Resources Information Center

    DeCosmo, Richard

    The Moraine Valley Community College (MVCC) 1978-79 Recruitment Program seeks to increase the pool of students who wish to attend college rather than compete more aggressively for those students who have already decided to participate in higher education. A special adjunct Retention Program has been developed to enhance the entire recruitment…

  13. Retention and relapse in clinical practice.

    PubMed

    Littlewood, S J; Kandasamy, S; Huang, G

    2017-03-01

    Maintaining teeth in their corrected positions following orthodontic treatment can be extremely challenging. Teeth have a tendency to move back towards the original malocclusion as a result of periodontal, gingival, occlusal and growth related factors. However, tooth movement can also occur as a result of normal age changes. Because orthodontics is unable to predict which patients are at risk of relapse, those which will remain stable and the extent of relapse that will occur in the long-term, clinicians need to treat all patients as if they have a high potential to relapse. To reduce this risk, long term retention is advocated. This can be a significant commitment for patients, and so retention and the potential for relapse must form a key part of the informed consent process prior to orthodontic treatment. It is vital that patients are made fully aware of their responsibilities in committing to wear retainers as prescribed in order to reduce the chance of relapse. If patients are unable or unwilling to comply as prescribed, they must be prepared to accept that there will be tooth positional changes following treatment. There is currently insufficient high quality evidence regarding the best type of retention or retention regimen, and so each clinician's approach will be affected by their personal, clinical experience and expertise, and guided by their patients' expectations and circumstances.

  14. Lung retention of cerium in humans.

    PubMed Central

    Pairon, J C; Roos, F; Iwatsubo, Y; Janson, X; Billon-Galland, M A; Bignon, J; Brochard, P

    1994-01-01

    A retrospective study was conducted to evaluate lung retention of particles containing cerium in subjects with and without previous occupational exposure to mineral dusts. Analytical transmission electron microscopy was performed on 459 samples of bronchoalveolar lavage (BAL) fluid and 75 samples of lung tissue. Study of the distribution of mineralogical species in human samples showed that particles containing cerium were encountered in less than 10% of subjects. The proportion of subjects with particles containing cerium in their biological samples was not different between controls and subjects with previous occupational exposure to fibrous or nonfibrous mineral dusts. This was considered as the background level of lung retention of cerium in the general population. By contrast, determination of the absolute concentration of particles containing cerium in BAL fluid and lung tissue samples showed that 1.2% (from BAL fluid) and 1.5% (from lung tissue) of subjects with previous exposure to mineral particles had high lung retention of particles containing cerium. This study is believed to be the first one in which lung retention of cerium was estimated in the general population. PMID:8130849

  15. 5 CFR 293.404 - Retention schedule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ....404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Employee Performance File System Records § 293.404 Retention schedule. (a)(1) Except as provided in § 293.405(a), performance ratings or documents supporting them are generally not permanent...

  16. Personnel Recruitment and Retention in Rural America.

    ERIC Educational Resources Information Center

    Helge, Doris; Marrs, Lawrence W.

    Recruitment and retention of special education teachers and related services staff have been persistent problems of rural school districts nationwide. High teacher attrition rates have serious ramifications for personnel development and program stability. Effective recruitment strategies for rural areas have four main components: (1) emphasis on…

  17. Structural Information Retention in Visual Art Processing.

    ERIC Educational Resources Information Center

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  18. Maximizing Female Retention In the Navy

    DTIC Science & Technology

    2014-03-01

    Initiatives in the Workplace ......................................8 b. Diversity Initiatives in the Navy................................................8...11 C. PAST STUDIES OF FEMALE RETENTION IN THE WORKPLACE ... workplace has become an increased focus in America. This is due in part to changing demographics within the United States. As cultural norms change

  19. Reframing Retention Strategy: A Focus on Process

    ERIC Educational Resources Information Center

    Schroeder, Charles C.

    2013-01-01

    When institutions engage in discussions regarding improving retention and graduation rates, invariably the conversation focuses on entering student characteristics, especially ACT and SAT scores and high school grades. Clearly, attracting and enrolling well-prepared and motivated high-ability students will certainly improve institutional measures…

  20. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... monitor recalls of the formula. Such records shall be retained for at least 1 year after the expiration...

  1. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  2. Recruitment and Retention with a Spin

    ERIC Educational Resources Information Center

    Lindgren, Rita; Hixson, Carla Braun

    2010-01-01

    Strategic planning and innovation at Bismarck State College (BSC) found common ground in the college's goal to recruit and retain employees in an environment of low unemployment and strong competition for skilled employees. BSC's strategic plan for 2007-09 included the objective "to increase retention of employees." One of the strategies…

  3. Testing to Enhance Retention in Human Anatomy

    ERIC Educational Resources Information Center

    Logan, Jessica M.; Thompson, Andrew J.; Marshak, David W.

    2011-01-01

    Recent work in cognitive psychology has shown that repeatedly testing one's knowledge is a powerful learning aid and provides substantial benefits for retention of the material. To apply this in a human anatomy course for medical students, 39 fill-in-the-blank quizzes of about 50 questions each, one for each region of the body, and four about the…

  4. Conjoint Retention of Maps and Related Discourse.

    ERIC Educational Resources Information Center

    Kulhavy, Raymond, W.; And Others

    1985-01-01

    Two experiments used fifth grade students to test the hypothesis that conjointly presented verbal/spatial information facilitates retrieval from either stimulus format. Results support the notion of conjoint retention which assumes that related verbal/spatial arrays are stored in a fashion which allows separate use of both formats during…

  5. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  6. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  7. Water Retention: Relieve This Premenstrual Symptom

    MedlinePlus

    ... If you continue to be troubled by monthly water retention, consult your doctor. He or she might suggest that you keep a symptom diary for a few months. This can help confirm that your symptoms are related to your menstrual cycle, rather than other causes of abdominal bloating — including ...

  8. Methylene blue improves brain oxidative metabolism and memory retention in rats.

    PubMed

    Callaway, Narriman Lee; Riha, Penny D; Bruchey, Aleksandra K; Munshi, Zeenat; Gonzalez-Lima, F

    2004-01-01

    Methylene blue (MB) increases mitochondrial oxygen consumption and restores memory retention in rats metabolically impaired by inhibition of cytochrome c oxidase. This study tested two related hypotheses using biochemical and behavioral techniques: (1) that low-level MB would enhance brain cytochrome c oxidation, as tested in vitro in brain homogenates and after in vivo administration to rats and (2) that corresponding low-dose MB would enhance spatial memory retention in normal rats, as tested 24 h after rats were trained in a baited holeboard maze for 5 days with daily MB posttraining injections. The biochemical in vitro studies showed an increased rate of brain cytochrome c oxidation with the low but not the high MB concentrations tested. The in vivo administration studies showed that the corresponding MB low dose (1 mg/kg) increased brain cytochrome c oxidation 24 h after intraperitoneal injection, but not after 1 or 2 h postinjection. In the behavioral studies, spatial memory retention in probe trials (percentage of visits to training-baited holes compared to total visits) was significantly better for MB-treated than saline control groups (66% vs. 31%). Together the findings suggest that low-dose MB enhances spatial memory retention in normal rats by increasing brain cytochrome c oxidase activity.

  9. ORTHODONTIC RETENTION. Studies of retention capacity, cost-effectiveness and long-term stability.

    PubMed

    Tynelius, Gudrun Edman

    2014-01-01

    Retention strategies, cost-effectiveness and long-term stability of treatment outcome are essential aspects of orthodontic treatment planning. The overall aim of this thesis was to compare and evaluate three different retention strategies, with special reference to short- and long-term clinical stability and cost-effectiveness. The approach was evidence-based, hence randomized controlled methodology was used in order to generate high levels of evidence. This thesis is based on four studies: Papers I and II are based on randomized controlled trials, evaluating the stability of treatment outcome after one and two years of retention, using three different retention strategies: a maxillary vacuum-formed retainer combined with a mandibular canine-to-canine retainer; a maxillary vacuum-formed retainer combined with stripping of the mandibular anterior teeth and a prefabricated positioner. Paper III presents a cost-minimization analysis of two years of retention treatment. Paper IV is based on a randomized controlled trial documenting the results five years post-retention. The following conclusions were drawn: Papers I and II. From a clinical perspective, asssessment after one year of retention disclosed that the three retention methods were successful in retaining the orthodontic treatment results. After two years of retention, all three retention methods were equally effective in controlling relapse at a clinically acceptable level. Most of the relapse occurred during the first year of retention; only minor or negligible changes were found during the second year. The subjects were grouped according to the level of compliance (excellent or good). After two years of retention there was a negative correlation between growth in body height and relapse of mandibular LII in the group of subjects with excellent compliance. The group with good compliance showed a positive correlation (Paper II, Figure 3). After two years of retention, growth in body height, initial crowding and

  10. Plastic debris retention and exportation by a mangrove forest patch.

    PubMed

    Ivar do Sul, Juliana A; Costa, Monica F; Silva-Cavalcanti, Jacqueline S; Araújo, Maria Christina B

    2014-01-15

    An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years).

  11. Statistical evaluation and choice of soil water retention models

    NASA Astrophysics Data System (ADS)

    Lennartz, Franz; Müller, Hans-Otfried; Nollau, Volker; Schmitz, Gerd H.; El-Shehawy, Shaban A.

    2008-12-01

    This paper presents the results of statistical investigations for the evaluation of soil water retention models (SWRMs). We employed three different methods developed for model selection in the field of nonlinear regression, namely, simulation studies, analysis of nonlinearity measures, and resampling strategies such as cross validation and bootstrap methods. Using these methods together with small data sets, we evaluated the performance of three exemplarily chosen types of SWRMs with respect to their parameter properties and the reliability of model predictions. The resulting rankings of models show that the favorable models are characterized by few parameters with an almost linear estimation behavior and close to symmetric distributions. To further demonstrate the potential of the statistical methods in the field of model selection, a modification of the four-parameter van Genuchten model is proposed which shows significantly improved and robust statistical properties.

  12. Reliability of in-stream retention metrics

    NASA Astrophysics Data System (ADS)

    Savickis, Jevgenijs; Zaramella, Mattia; Marion, Andrea

    2016-04-01

    The temporary solute retention within transient storage zones (TSZs) has been shown to have a large effect on the transport of solute. This retention can significantly increase the overall in-stream residence time and as consequence increase the contact time of solute with aquatic interfaces (biota, sediment) and living species. An important question that arises is whether the currently available metrics adequately represent retention mechanism. This work attempts to investigate the reliability of two existing measures, the hydrological retention factor (Rh) and the fraction of median travel time due to transient storage zone (Fmed200). For this purpose, five conservative tracer tests were conducted in four European streams with distinct morphological, sediment composition, vegetation and hydraulic characteristics. The obtained breakthrough curves (BTCs) were used to derive storage zone parameters (storage zone area, storage zone exchange coefficient and mean residence time), which then were used for comparison and in the metric expressions. The storage zone parameters were computed using a single TSZ model OTIS-P and a multiple TSZ model STIR. The STIR model was applied to BTCs as an additional tool to separate TSZs into short timescale (ST) and long timescale (LT). The study results reveal correlation between Fmed200 and LT residence time T2 values, where the streams with the lowest Fmed200 (0.01-0.96) have the smallest long timescale storage zones T2 values, ranging from 912 s to 1402 s. The findings also demonstrate an influence of discharge rate on both retention metrics. The greatest Fmed200 (6.19) and Rh (0.938) values are calculated for the streams with low discharge rates (0.08-0.10 m3s-1) and a relatively high ST storage zone residence times T1 (159 s to 351 s). Results show that the Fmed200 and Rh metrics are strongly affected by the short timescale transient storage zones, whereas the LT storage zones (hyporheic) effects are not taken into account.

  13. Transport and retention of multi-walled carbon nanotubes in saturated porous media: effects of input concentration and grain size.

    PubMed

    Kasel, Daniela; Bradford, Scott A; Šimůnek, Jiří; Heggen, Marc; Vereecken, Harry; Klumpp, Erwin

    2013-02-01

    Water-saturated column experiments were conducted to investigate the effect of input concentration (C₀) and sand grain size on the transport and retention of low concentrations (1, 0.01, and 0.005 mg L⁻¹) of functionalized ¹⁴C-labeled multi-walled carbon nanotubes (MWCNT) under repulsive electrostatic conditions that were unfavorable for attachment. The breakthrough curves (BTCs) for MWCNT typically did not reach a plateau, but had an asymmetric shape that slowly increased during breakthrough. The retention profiles (RPs) were not exponential with distance, but rather exhibited a hyper-exponential shape with greater retention near the column inlet. The collected BTCs and RPs were simulated using a numerical model that accounted for both time- and depth-dependent blocking functions on the retention coefficient. For a given C₀, the depth-dependent retention coefficient and the maximum solid phase concentration of MWCNT were both found to increase with decreasing grain size. These trends reflect greater MWCNT retention rates and a greater number of retention locations in the finer textured sand. The fraction of the injected MWCNT mass that was recovered in the effluent increased and the RPs became less hyper-exponential in shape with higher C₀ due to enhanced blocking/filling of retention locations. This concentration dependency of MWCNT transport increased with smaller grain size because of the effect of pore structure and MWCNT shape on MWCNT retention. In particular, MWCNT have a high aspect ratio and we hypothesize that solid phase MWCNT may create a porous network with enhanced ability to retain particles in smaller grain sized sand, especially at higher C₀. Results demonstrate that model simulations of MWCNT transport and fate need to accurately account for observed behavior of both BTCs and RPs.

  14. Retention of participants in medication-assisted programs in low- and middle-income countries: an international systematic review

    PubMed Central

    Feelemyer, Jonathan; Jarlais, Don Des; Arasteh, Kamyar; Abdul-Quader, Abu S.; Hagan, Holly

    2017-01-01

    Background and aims Medication-assisted treatment (MAT) is a key component in overdose prevention, reducing illicit opiate use and risk of blood-borne virus infection. By retaining participants in MAT programs for longer periods of time, more noticeable and permanent changes in drug use, risk behavior and quality of life can be achieved. Many studies have documented retention in MAT programs in high-income countries, using a 50% average 12-month follow-up retention rate as a marker for a successful MAT program. This study contributes to a systematic understanding of how successful programs have been in retaining participants in low- and middle-income countries (LMIC) over time. Methods Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic literature search to identify MAT program studies that documented changes in retention over time for participants in buprenorphine and methadone programs in LMIC. Retention was measured for participants by length of follow-up, type of MAT and treatment dosage. Results There were 58 MAT program studies, with 27 047 participants eligible for inclusion in the review. Overall average retention after 12 months was 54.3% [95% confidence interval (CI) = 46.2, 63.7%]. Overall average retention was moderately good for both buprenorphine (48.3%, 95% CI = 22.1, 74.6%) and methadone (56.6%, 95% CI = 45.9%, 67.3%) after 12 months of treatment. Among programs using methadone there was no statistically significant difference in average retention by dosage level, and the 10 highest and lowest dosage programs obtained similar average retention levels after 12 months. Conclusion Medication-assisted treatment programs in low- and middle-income countries achieve an average 50% retention rate after 12 months, with wide variation across programs but little difference between those using buprenorphine versus methadone. PMID:23859638

  15. 48 CFR 4.705 - Specific retention periods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATIVE MATTERS Contractor Records Retention 4.705 Specific retention periods. The contractor shall retain... specific name or form number. Although the descriptive identifications may not conform to normal...

  16. 48 CFR 4.705 - Specific retention periods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATIVE MATTERS Contractor Records Retention 4.705 Specific retention periods. The contractor shall retain... specific name or form number. Although the descriptive identifications may not conform to normal...

  17. Nutrient retention in riparian floodplains on landscape scale, the necessity for a monthly retention approach.

    PubMed

    Natho, S; Venohr, M

    2012-01-01

    This study analyses the computed nitrogen retention, the distribution and the extent of riparian floodplains of three German rivers, as input data and application of the retention model has not been carried out on landscape scale so far. The Software FLYS 2.1.3 was used for the calculation of the floodplain extent and depth at certain discharges. Thus a first empirical approach is suggested to quantify the share of load that enters the floodplain (incoming load) and the extent of floodplain as variables depending on discharge ratios. Measured loads have subsequently been applied to the presented approach to calculate incoming loads on a monthly and yearly basis for the years 1999 and 2002. Finally, linear and exponential yearly retention models were applied, obtained from the literature. Large variations in the retention results were found between the years and the models and between monthly and yearly calculations. In hydrologically average years, calculated retention rates are in the range of reported values (440-670 kg N ha⁻¹ yr⁻¹), whereas for wet years, retention values account for 1,400 kg N ha⁻¹ yr⁻¹. Consequently, this approach needs to be improved to reduce overestimation by considering more complex characteristics of the floodplain, but generally its application is possible on the landscape scale.

  18. Etude des effets du martelage repetitif sur les contraintes residuelles

    NASA Astrophysics Data System (ADS)

    Hacini, Lyes

    L'assemblage par soudage peut engendrer des contraintes residuelles. Ces contraintes provoquent des fissurations prematurees et un raccourcissement de la duree de vie des composants. Dans ce contexte, le martelage robotise est utilise pour relaxer ces contraintes residuelles. Trois volets sont presentes: le premier est l'evaluation des effets des impacts unitaires repetes sur le champ de contraintes developpe dans des plaques d'acier inoxydable austenitique 304L vierges ou contenant des contraintes residuelles initiales. Dans la deuxieme partie de ce projet, le martelage est applique grace au robot SCOMPI. Les contraintes residuelles induites et relaxees par martelage sont ensuite mesurees par la methode des contours, qui a ete adaptee a cet effet. Dans la troisieme partie, le martelage est modelise par la methode des elements finis. Un modele axisymetrique developpe grace au logiciel ANSYS permet de simuler des impacts repetes d'un marteau elastique sur une plaque ayant un comportement elastoplastique.

  19. The Tennessee Lottery Scholarship Program: Impact on Retention

    ERIC Educational Resources Information Center

    Puryear, Carol G.

    2009-01-01

    This study examined if the Tennessee Education Lottery Scholarship (TELS), which began in 2004, was related to student retention at the six Tennessee Board of Regents four-year institutions. This study investigated the impact of the TELS on student retention at TBR universities and general knowledge regarding retention. Post-facto data were…

  20. Policies and Practice: A Focus on Higher Education Retention.

    ERIC Educational Resources Information Center

    American Association of State Colleges and Universities, Washington, DC.

    This book, based on a discussion at an interactive videoconference, examines student diversity issues and retention strategies in the context of the Sallie Mae National Retention Project that addressed state expectations for more accountability and federal reporting requirements on graduation and retention. The eight chapters focus on equity as it…

  1. 46 CFR 308.600 - Records retention requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Records retention requirement. 308.600 Section 308.600 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE Records Retention § 308.600 Records retention requirement. The records specified in §§ 308.8, 308.517,...

  2. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Retentive and splinting pin. 872.3740 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin. (a) Identification. A retentive and splinting pin is a device made of austenitic alloys or alloys containing...

  3. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Retentive and splinting pin. 872.3740 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin. (a) Identification. A retentive and splinting pin is a device made of austenitic alloys or alloys containing...

  4. 48 CFR 4.704 - Calculation of retention periods.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Calculation of retention periods. 4.704 Section 4.704 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Contractor Records Retention 4.704 Calculation of retention periods. (a) The...

  5. Framing Retention for Institutional Improvement: A 4 Ps Framework

    ERIC Educational Resources Information Center

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps framework for student retention strategy is a construct for reframing the retention discussion in a way that enables institutional improvement by challenging some conventional wisdom and prevailing perspectives that have characterized retention strategy for years. It opens new possibilities for action and improvement by suggesting that…

  6. Retention Initiatives Used by Professional Master's Athletic Training Program Directors

    ERIC Educational Resources Information Center

    Bowman, Thomas G.; Dodge, Thomas M.; Mazerolle, Stephanie M.

    2015-01-01

    Context: Many professional master's athletic training program directors believe retention is a problem facing athletic training education. However, it remains unknown what steps, if any, are taken to improve retention. Objective: To inquire with program directors about their respective methods and interventions aimed at increasing retention rates.…

  7. Family, personality, and social risk factors impacting the retention rates of first-year Hispanic and Anglo college students.

    PubMed

    Pidcock, B W; Fischer, J L; Munsch, J

    2001-01-01

    This study investigated familial and behavioral differences between Hispanic and Anglo-American first-year college students. Analyses of variance and chi-square analyses were used to test for ethnic differences in (a) risk factors associated with family dysfunction, family addictions, personality factors, and social experiences, (b) student problem behaviors, namely alcohol use, drug use, and eating disorders, (c) a one-year follow-up of student retention, and (d) specific factors related to retention at the one-year follow-up. The Hispanic freshmen appeared to demonstrate resilience despite a lack of mentoring and greater paternal addiction. However, the one-year follow-up suggested that Hispanic females were at particular risk for leaving school. To improve college retention rates, social policy should focus on Hispanic students' vulnerabilities and strengths in making important developmental transitions.

  8. Influence of helium on deuterium retention in reduced activation ferritic martensitic steel (F82H) under simultaneous deuterium and helium irradiation

    NASA Astrophysics Data System (ADS)

    Yakushiji, K.; Lee, H. T.; Oya, M.; Hamaji, Y.; Ibano, K.; Ueda, Y.

    2016-02-01

    Deuterium and helium retention in Japanese reduced activation ferritic martensitic (RAFM) steel (F82H) under simultaneous D-He irradiation at 500, 625, 750, and 818 K was studied. This study aims to clarify tritium retention behavior in RAFM steels to assess their use as plasma facing materials. The irradiation fluence was kept constant at 1 × 1024 D m-2. Four He desorption peaks were observed with He retention greatest at 625 K. At T > 625 K a monotonic decrease in He retention was observed. At all temperatures a systematic reduction in D retention was observed for the simultaneous D-He case in comparison to D-only case. This suggests that He implanted at the near surface in RAFM steels may reduce the inward penetration of tritium in RAFM steels that would result in lower tritium inventory for a given fluence.

  9. Retention Curve Measurement for Sands Using a TDR-based Long Column and Modified Tempe Cell

    NASA Astrophysics Data System (ADS)

    Sakaki, T.; Illangasekare, T. H.

    2006-12-01

    Long column and Tempe cell are typical methods for measuring the water retention curves for soils. In the conventional long column method utilizing a stack of rings, water saturation profile is determined gravimetrically. X-ray or gamma ray attenuation are non-destructive methods but require complex and expensive devices and involve the use of photon sources. Time domain reflectometry (TDR) is an alternative to these radioactive methods for measuring water content profile along the column. Typical Tempe cells have a sample height of 3 to 6 cm. Suction is applied to the sample to induce drainage and monitored outflow is used to calculate the average water saturation of the sample, which potentially leads to obscuring the distinct displacement pressure value and results in a smoothed retention curve. In this study, we assumed that direct point-wise measurements provide retention curves that represent the physical behavior of the porous medium. We first determined retention curves for a number of well-sorted industrial silica sands using a long column that allows such point-wise measurements by TDR probes horizontally installed at eleven different elevations. Then, we modified a commercially available Tempe cell so that water saturation and capillary pressure head at a physical point in the cell, as well as the conventional height-averaged water saturation, can be measured simultaneously. Comparison of the conventional and point- measured retention curves that were obtained simultaneously for the identical sand samples revealed that 1) point-measured retention curves were identical to the ones measured in the long column, 2) the artifact of using height-averaged saturation values as pointed out by Dane et al. [1992] was experimentally confirmed. We further show that the displacement pressure head can possibly be underestimated especially for coarse soils when height-averaged water saturation is used. This is more significant for oil-water and DNAPL-water systems where

  10. Using simulation to enhance the acquisition and retention of clinical skills in neonatology.

    PubMed

    Anderson, JoDee M; Warren, Jamie B

    2011-04-01

    Neonatal care occurs in extremely complex and dynamic environments and requires providers to operate under intense time pressure in coordination with multiple disciplines. Teaching the clinical skills requisite to effective practice requires the meticulous application of curricular design principles. Simulation can be used as an effective instructional strategy in achieving learner acquisition and retention of the cognitive, technical, and behavioral skills essential to optimal delivery of care in neonatology.

  11. Retention and processing methods of nasal prosthesis.

    PubMed

    Goiato, Marcelo Coelho; Mancuso, Daniela Nardi; Zuccolotti, Bruna Carolina Rossati; Murakawa, Ana Cristina; Lima, Daniela Coelho de; Santos, Daniela Micheline dos; Andreotti, Agda Marobo

    2012-11-01

    Patients with congenital malformations, traumatic or pathological mutilation and maxillofacial developmental disorders can be restored aesthetically and emotionally by the production and use of facial prostheses. The aim of this study was to review the literature about the retention and processing methods of facial prostheses, and discuss their characteristics. A literature review on Medline (PubMed) database was performed by using the keywords "maxillofacial prosthesis, silicone, esin, pigment, cosmetic, prosthetic nose", based on articles published from 1956 to 2010. Several methods of retention, from adhesives to the placement of implants, and different processing methods such as laser, CAD/CAM and rapid prototyping technologies have been reported. There are advantages and disadvantages of each procedure, and none can be classified as better compared to others.

  12. Selective Surface Modification on Lubricant Retention

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

    2016-11-01

    While surface patterns are effective in improving tribological properties, nevertheless they alter the surface wettability, which will in turn affect the surface-lubricant interactions. When there is a shortage of lubricant on a patterned surface, the lubricant stored inside the cavities will be extracted to compensate the surface lubricant dissipation. Additionally, the lubricant retention effect provided by the cavities is competing with the release of the lubricant. With weak surface-lubricant interaction, the retention is limited. Therefore, the lubrication will have a sudden failure, giving a dramatic transition to abrasive wear. To improve the performance of polar lubricants on hydrophobic polymer surfaces, both topographical and selective surface modifications were incorporated on injection molded polypropylene surfaces. Distinctive lubrication improvement was observed when the surface structure density for the lubricant storage was high, and the release of the lubricant was controlled by the interaction with the selectively modified surfaces.

  13. Improving student retention in computer engineering technology

    NASA Astrophysics Data System (ADS)

    Pierozinski, Russell Ivan

    The purpose of this research project was to improve student retention in the Computer Engineering Technology program at the Northern Alberta Institute of Technology by reducing the number of dropouts and increasing the graduation rate. This action research project utilized a mixed methods approach of a survey and face-to-face interviews. The participants were male and female, with a large majority ranging from 18 to 21 years of age. The research found that participants recognized their skills and capability, but their capacity to remain in the program was dependent on understanding and meeting the demanding pace and rigour of the program. The participants recognized that curriculum delivery along with instructor-student interaction had an impact on student retention. To be successful in the program, students required support in four domains: academic, learning management, career, and social.

  14. Retention technique #1. Developing managerial warmth.

    PubMed

    Davidhizar, R

    1989-01-01

    A manager who has interpersonal warmth is not simply gullible or naive, but instead possesses a valuable skill in reaching others. In most manager-employee relationships, some degree of limit-setting and judgment are necessary; however, warmth integrated with limit-setting is more satisfying for both employee and manager. Although warmth as an interpersonal phenomenon is affected by the employee's perception, certain managerial actions can increase the likelihood of being perceived as warm; yet, in spite of careful adherence to the guidelines for communicating warmth, managerial warmth will still be rejected in some situations. As is true of any managerial technique, the effective use of warmth requires an assessment of the employee's personality and the approach most appropriate for the situation at hand. The excellent manager is able to quickly adapt, matching the level of warmth to the situation. See Nurse Manager Retention Factors for viewpoints from nurses themselves. Interpersonal management style is an important retention factor.

  15. The Successful Mobilization of a Campus Community for Student Retention. Report of the University Retention Steering Committee.

    ERIC Educational Resources Information Center

    Eastern Michigan Univ., Ypsilanti.

    Components of a student retention program at Eastern Michigan University are examined; for each effort to improve retention, project objectives and design, results, and recommendations are presented. Retention initiatives, decided upon as a result of a campus-wide mobilization of effort, include: a student-focused orientation system, a fast track…

  16. 78 FR 57927 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ...The OCC, Board, FDIC, Commission, FHFA, and HUD (the agencies) are seeking comment on a joint proposed rule (the proposed rule, or the proposal) to revise the proposed rule the agencies published in the Federal Register on April 29, 2011, and to implement the credit risk retention requirements of section 15G of the Securities Exchange Act of 1934 (15. U.S.C. 78o-11), as added by section 941 of......

  17. Family and Other Impacts on Retention

    DTIC Science & Technology

    1992-04-01

    the first- and second-stage samples were chosen with minimum replacement ( Chromy , 1979). The minimum replacement procedure is equivalent to without...testing differences between groups. REFERENCES Chromy , J. (1979). Sequential sample -election methods. Proceedings of the American Statistical...Soldiers Married to Civilfan Spouses B- 324 Table 5.13 - Standard Errors Retention Plans by Pay Grade and Sense of Community Quality SENSE OF COMMUNITY

  18. Meeting Canadian Forces Expansion Goals through Retention

    DTIC Science & Technology

    2010-05-01

    strategies to improve 13 For the purposes of this study, the Quantitative Group refers to new...the CF. With improved retention, CF expansion and transformation will be facilitated to allow the CF to best meet Canada’s national security...way, under conditions that could lead to loss of life . 23 In no other profession in Canada, (except perhaps in isolated cases, certain emergency

  19. 300 Area Building Retention Evaluation Mitigation Plan

    SciTech Connect

    D. J. McBride

    2007-07-03

    Evaluate the long-term retention of several facilities associated with the PNNL Capability Replacement Laboratory and other Hanfor mission needs. WCH prepared a mitigation plan for three scenarios with different release dates for specific buildings. The evaluations present a proposed plan for providing utility services to retained facilities in support of a long-term (+20 year) lifespan in addition to temporary services to buildings with specified delayed release dates.

  20. Retention Quick Polls of Three Navy Communities

    DTIC Science & Technology

    2011-03-01

    FY07, and additional incentives are being considered to motivate personnel to “Stay Navy”. Since retention decisions are impacted by a number of...issues, it is useful to know what motivates Sailors to stay or leave, and what incentives influence that decision. This report presents results of...three Navy Quick Polls that asked about job satisfaction, continuation intentions, motivators to stay or leave, and incentives that would increase the

  1. Ostéosynthèse des fractures des métacarpiens et des phalanges de la main par mini plaque: à propos de 12 cas

    PubMed Central

    Moncef, Erraji; Abdelhafid, Derfoufi; Abdessamad, Kharraji; Omar, Agoumi; Najib, Abdeljaouad; Abdelkrim, Daoudi; Hicham, Yacoubi

    2016-01-01

    Le traitement des fractures instables des métacarpes et des phalanges reste un objet de controverse. Peu de séries ont été rapportées dans la littérature, rendant leur analyse difficile. Nous rapportons une étude rétrospective comportant 12 patients, opérés par cette technique, ayant eu des fractures déplacées des métacarpes ou des phalanges, sur une période de deux ans. Les résultats globaux ont été bons dans 75% des cas, moyenne dans 16,5% des cas et mauvais dans 8,5% des cas. La stabilité du montage par mini plaques des fractures instables des métacarpiens et des phalanges ont permis une mobilisation précoce des articulations de la main, évitant ainsi la raideur. PMID:27800079

  2. Review of Attrition and Retention Research for the Canadian Forces

    DTIC Science & Technology

    2008-10-01

    est des militaires du rang (MR) dans les groupes professionnels de la Marine. Plusieurs stratégies d’intervention ont été recommandées, et les taux...d’attrition pour les deux groupes sont désormais comparables comme c’est le cas pour les autres groupes professionnels des FC. Des études... professionnels , le programme d’attribution de commission et surtout les années de service. En examinant les données des dernières années, on constate

  3. Recruitment and retention of novice faculty.

    PubMed

    Hessler, Karen; Ritchie, Heidi

    2006-05-01

    As nursing faculty members younger than 35, we consider ourselves to be in the minority. Our concern about the future of nursing education has driven us to consider ways to recruit and retain new, young faculty. To stimulate discussion, 10 suggestions for schools of nursing in the recruitment and retention of new faculty are presented: provide guidance, foster socialization, encourage flexibility, conduct orientation, provide support, facilitate collaboration, allow for mistakes, coordinate teaching assignments, grow your own, and offer rewards. While this list is far from complete, we believe it is a starting point from which schools could develop individual strategies for recruitment and retention of faculty members in nursing academia. The nursing shortage continues to intensify the lack of nursing faculty members. As a result, strategies to recruit and retain young faculty members only gain importance. Generations are changing, and it is important that schools of nursing are aware that recruitment and retention strategies that may have been successful in the past, may now be obsolete.

  4. Retention of perceptual generalization of fear extinction.

    PubMed

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed.

  5. High efficiency diffusion molecular retention tumor targeting.

    PubMed

    Guo, Yanyan; Yuan, Hushan; Cho, Hoonsung; Kuruppu, Darshini; Jokivarsi, Kimmo; Agarwal, Aayush; Shah, Khalid; Josephson, Lee

    2013-01-01

    Here we introduce diffusion molecular retention (DMR) tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT) injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding) and RAD (control) probes were synthesized bearing DOTA (for (111) In(3+)), a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111)In] RGD and [(111)In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111)In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.). The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide), which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters) for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  6. Determinants of feedback retention in soccer players

    PubMed Central

    Januário, Nuno; Rosado, António; Mesquita, Isabel; Aguilar-Parra, José M.

    2016-01-01

    Abstract This study analyzed soccer players’ retention of coaches’ feedback during training sessions. We intended to determine if the retention of information was influenced by the athletes’ personal characteristic (age, gender and the sports level), the quantity of information included in coach’s feedback (the number of ideas and redundancy), athletes’ perception of the relevance of the feedback information and athletes’ motivation as well as the attention level. The study that was conducted over the course of 18 sessions of soccer practice, involved 12 coaches (8 males, 4 females) and 342 athletes (246 males, 96 females), aged between 10 and 18 years old. All coach and athlete interventions were transposed to a written protocol and submitted to content analysis. Descriptive statistics and multiple linear regression were calculated. The results showed that a substantial part of the information was not retained by the athletes; in 65.5% of cases, athletes experienced difficulty in completely reproducing the ideas of the coaches and, on average, the value of feedback retention was 57.0%. Six variables with a statistically significant value were found: gender, the athletes’ sports level, redundancy, the number of transmitted ideas, athletes’ perception of the relevance of the feedback information and the athletes’ motivation level. PMID:28149387

  7. INTRODUCTION OF SPRINKLER FOR CONTINUATION OF WATER RETENTIVENESS

    NASA Astrophysics Data System (ADS)

    Kuribayashi, Mokichi; Yasuda, Kohei

    This report shows the study for the development of the efficient sprinkler system which contribute to the sustainability of water-retentive pavement. Water Retentive Pavement is one of the green engineering that is hoped to mitigate heat-island phenomenon. It is necessary for water retentiveness to keep showing the best performance, because it has shortage of water retentiveness, unless it rains. Therefore, the sprinkler system which is maximized its performance of water retentiveness at any time has been developed and it has started operating in June 2010.

  8. Do goethite surfaces really control the transport and retention of multi-walled carbon nanotubes in chemically heterogeneous porous media?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transport and retention behavior of multiwalled carbon nanotubes (MWCNTs) was studied in mixtures of negatively charged quartz sand (QS) and positively charged goethite-coated sand (GQS) to assess the role of chemical heterogeneity. The linear equilibrium sorption model provided a good description o...

  9. Peste des Petits Ruminants Virus.

    PubMed

    Baron, M D; Diallo, A; Lancelot, R; Libeau, G

    2016-01-01

    Peste des petits ruminants virus (PPRV) causes a severe contagious disease of sheep and goats and has spread extensively through the developing world. Because of its disproportionately large impact on the livelihoods of low-income livestock keepers, and the availability of effective vaccines and good diagnostics, the virus is being targeted for global control and eventual eradication. In this review we examine the origin of the virus and its current distribution, and the factors that have led international organizations to conclude that it is eradicable. We also review recent progress in the molecular and cellular biology of the virus and consider areas where further research is required to support the efforts being made by national, regional, and international bodies to tackle this growing threat.

  10. Dysfunctional Elimination Behaviors and Associated Complications in School-Age Children

    ERIC Educational Resources Information Center

    Kistner, Mary

    2009-01-01

    Lack of privacy, risk of bullying, limited access, lack of essential products for good hygiene, and dirty bathrooms can all contribute to encouraging a child to withhold urine and stool while in school. Withholding behaviors over time can create a condition known as dysfunctional elimination syndrome (DES). DES is any pattern of voiding or…

  11. Greening America's Capitals - Des Moines, IA

    EPA Pesticide Factsheets

    Report from Greening America's Capitals project in Des Moines, IA, to help the city enhance the 6th Avenue Corridor with pedestrian and bike improvements and green infrastructure to manage stormwater.

  12. Investigation of data retention under current bias for phase change memory

    NASA Astrophysics Data System (ADS)

    Lu, Yao-Yao; Cai, Dao-Lin; Chen, Yi-Feng; Wang, Yue-Qing; Wei, Hong-Yang; Huo, Ru-Ru; Song, Zhi-Tang

    2016-10-01

    With Phase-change memory (PCM), information can be stored as different resistance states even when not powered. In order to accurately characterize the reliability of PCM devices, data retention has to be tested carefully. In this paper, a new test method is applied to measure the data retention of T-shaped PCM devices. This method makes it possible to accelerate crystallization in the amorphous area by using current bias. The new method works based on the field-induced crystallization theory, and could be able to gather fast and detailed information about high-resistance state's failure process, and at the same time, it could avoid issues related to high temperature. Experimental data for T-shaped PCM devices based on Ge2Sb2Te5 are presented and analyzed. An exponential trend-line of failure time t versus reciprocal bias current 1/I shows only negligible deviation of the measured data points, enabling the extrapolation of the retention behavior for ten-year lifetime. A maximum disturb current value of 5.08 μA is extracted to guarantee the ten years data retention requirement for PCM applications.

  13. Grafting zwitterionic polymer onto cryogel surface enhances protein retention in steric exclusion chromatography on cryogel monolith.

    PubMed

    Tao, Shi-Peng; Zheng, Jie; Sun, Yan

    2015-04-10

    Cryogel monoliths with interconnected macropores (10-100μm) and hydrophilic surfaces can be employed as chromatography media for protein retention in steric exclusion chromatography (SXC). SXC is based on the principle that the exclusion of polyethylene glycol (PEG) on both a hydrophilic chromatography surface and a protein favors their association, leading to the protein retention on the chromatography surface. Elution of the retained protein can be achieved by reducing PEG concentration. In this work, the surface of polyacrylamide-based cryogel monolith was modified by grafting zwitterionic poly(carboxybetaine methacrylate) (pCBMA), leading the increase in the surface hydrophilicity. Observation by scanning electron microscopy revealed the presence of the grafted pCBMA chain clusters on the cryogel surface, but pCBMA grafting did not result in the changes of the physical properties of the monolith column, and the columns maintained good recyclability in SXC. The effect of the surface grafting on the SXC behavior of γ-globulin was investigated in a wide flow rate range (0.6-12cm/min). It was found that the dynamic retention capacity increased 1.4-1.8 times by the zwitterionic polymer grafting in the flow rate range of 1.5-12cm/min. The mechanism of enhanced protein retention on the zwitterionic polymer-grafted surface was proposed. The research proved that zwitterionic polymer modification was promising for the development of new materials for SXC applications.

  14. Evaluation of systemic administration of Boswellia papyrifera extracts on spatial memory retention in male rats.

    PubMed

    Mahmoudi, Ali; Hosseini-Sharifabad, Ali; Monsef-Esfahani, Hamid R; Yazdinejad, Ali R; Khanavi, Mahnaz; Roghani, Ali; Beyer, Cordian; Sharifzadeh, Mohammad

    2011-07-01

    Time-dependent effects of ethanolic extract of Boswellia papyrifera, administered systemically, on spatial memory retention in the Morris water maze were investigated in male rats. A total extract of Boswellia papyrifera (300 mg/kg) was administered every eight hours to three groups of rats by gavage for 1, 2 and 4 weeks. In a separate set of experiments, three doses of a fraction of the extract, called the boswellic acids (100, 200 and 300 mg/kg) were administered by gavage to three groups of rats three times a day for 2 weeks. Following these applications, animals were trained for 4 days. Behavioral testing for evaluation of spatial memory retention was performed 48 h after completion of training. Boswellia papyrifera extracts and boswellic acids caused a significant reduction in escape latency and distance traveled but had no influence on swimming speed. These findings provide evidence that Boswellia papyrifera extracts affect spatial memory retention irrespective of the treatment period. In addition our data show that systemic administration of the boswellic acids fraction enhanced spatial memory retention in a dose-dependent manner. These improving effects may be due to some extent to the interactions of these products with inflammatory mediators, neurotransmitter signaling cascades or protein kinase pathways in the brain.

  15. Installation-Restoration Program. Phase 2. Confirmation/quantification. Stage 1. Iowa Air National Guard, Des Moines Municipal Airport, Des Moines, Iowa. Final report, August 1984-February 1985

    SciTech Connect

    Buchmiller, R.C.

    1986-02-01

    Soil and water samples were collected for chemical analyses from unconsolidated loess and glacial till surficial materials at 4 sites on the Des Moines Air National Guard Base. Analyses of samples used gas chromatograph-flame ionization detector (GC-FID) scans on all samples and gas chromatograph-mass spectrometer (GC-MS) on selected samples. Interpretation was based on correlation of GC-FID scan retention time peaks between field sites and samples of known contaminated material or wastes. Results of GC-MS indicate the presence of acenapthene, phenenthrene, pyrene, 1,2-dichlorobenzene, fluoranthene, butylbenzylphthalate, aliphatic hydrocarbons, naphthalenes, cyclohexanes, benzenes, and other organic substances in on or more of the samples. GC-MS analyses indicate the presence of priority pollutants in excess of detection limit concentrations at each site.

  16. Caracterisation des proprietes acoustiques des materiaux poreux a cellules ouvertes et a matrice rigide ou souple

    NASA Astrophysics Data System (ADS)

    Salissou, Yacoubou

    L'objectif global vise par les travaux de cette these est d'ameliorer la caracterisation des proprietes macroscopiques des materiaux poreux a structure rigide ou souple par des approches inverses et indirectes basees sur des mesures acoustiques faites en tube d'impedance. La precision des approches inverses et indirectes utilisees aujourd'hui est principalement limitee par la qualite des mesures acoustiques obtenues en tube d'impedance. En consequence, cette these se penche sur quatre problemes qui aideront a l'atteinte de l'objectif global precite. Le premier probleme porte sur une caracterisation precise de la porosite ouverte des materiaux poreux. Cette propriete en est une de passage permettant de lier la mesure des proprietes dynamiques acoustiques d'un materiau poreux aux proprietes effectives de sa phase fluide decrite par les modeles semi-phenomenologiques. Le deuxieme probleme traite de l'hypothese de symetrie des materiaux poreux selon leur epaisseur ou un index et un critere sont proposes pour quantifier l'asymetrie d'un materiau. Cette hypothese est souvent source d'imprecision des methodes de caracterisation inverses et indirectes en tube d'impedance. Le critere d'asymetrie propose permet ainsi de s'assurer de l'applicabilite et de la precision de ces methodes pour un materiau donne. Le troisieme probleme vise a mieux comprendre le probleme de transmission sonore en tube d'impedance en presentant pour la premiere fois un developpement exact du probleme par decomposition d'ondes. Ce developpement permet d'etablir clairement les limites des nombreuses methodes existantes basees sur des tubes de transmission a 2, 3 ou 4 microphones. La meilleure comprehension de ce probleme de transmission est importante puisque c'est par ce type de mesures que des methodes permettent d'extraire successivement la matrice de transfert d'un materiau poreux et ses proprietes dynamiques intrinseques comme son impedance caracteristique et son nombre d'onde complexe. Enfin, le

  17. Activation of the bacterial thermosensor DesK involves a serine zipper dimerization motif that is modulated by bilayer thickness

    PubMed Central

    Cybulski, Larisa Estefanía; Ballering, Joost; Moussatova, Anastassiia; Inda, Maria Eugenia; Vazquez, Daniela B.; Wassenaar, Tsjerk A.; de Mendoza, Diego; Tieleman, D. Peter; Killian, J. Antoinette

    2015-01-01

    DesK is a bacterial thermosensor protein involved in maintaining membrane fluidity in response to changes in environmental temperature. Most likely, the protein is activated by changes in membrane thickness, but the molecular mechanism of sensing and signaling is still poorly understood. Here we aimed to elucidate the mode of action of DesK by studying the so-called “minimal sensor DesK” (MS-DesK), in which sensing and signaling are captured in a single transmembrane segment. This simplified version of the sensor allows investigation of membrane thickness-dependent protein–lipid interactions simply by using synthetic peptides, corresponding to the membrane-spanning parts of functional and nonfunctional mutants of MS-DesK incorporated in lipid bilayers with varying thicknesses. The lipid-dependent behavior of the peptides was investigated by circular dichroism, tryptophan fluorescence, and molecular modeling. These experiments were complemented with in vivo functional studies on MS-DesK mutants. Based on the results, we constructed a model that suggests a new mechanism for sensing in which the protein is present as a dimer and responds to an increase in bilayer thickness by membrane incorporation of a C-terminal hydrophilic motif. This results in exposure of three serines on the same side of the transmembrane helices of MS-DesK, triggering a switching of the dimerization interface to allow the formation of a serine zipper. The final result is activation of the kinase state of MS-DesK. PMID:25941408

  18. Linkage to and retention in care following healthcare transition from pediatric to adult HIV care.

    PubMed

    Ryscavage, Patrick; Macharia, Thomas; Patel, Devang; Palmeiro, Robyn; Tepper, Vicki

    2016-01-01

    Outcomes following healthcare transition (HCT) from pediatric to adult HIV care are not well described. We sought to describe clinical outcomes following HCT within our institution among young adults with behavioral-acquired (N = 31) and perinatally-acquired (N = 19) HIV. We conducted a retrospective cohort study among HIV-infected adults who attempted transition from pediatric to adult HIV care within our institution. The primary end point was retention in care, defined as the completion of at least two visits over 12 months following linkage to adult care. Additional end points include time to linkage to adult care, and changes in CD4 + T cell count and HIV RNA across time. Outcomes were compared between perinatal and behavioral HIV cohorts. Binary data were analyzed using the Fisher exact test and continuous data were analyzed using the Mann-Whitney test. Forty-three (86%) of 50 patients were successfully linked to adult care. The median time to linkage was 98 days. Fifty percent of patients achieved full retention in care at 12 months post-linkage. Though those with behavioral-acquired HIV attempted transfer at an older age, the groups did not differ in rates of linkage and retention in adult care. CD4 + T cell counts and rates of viral suppression did not differ between pre- and post-HCT periods. Despite high rates of successful linkage to adult care in our study population, rates of retention in adult HIV care following HCT were low. These results imply that challenges remain in the adult HIV care setting toward improving the HCT process.

  19. Strategies to improve retention in randomised trials

    PubMed Central

    Brueton, Valerie C; Tierney, Jayne; Stenning, Sally; Harding, Seeromanie; Meredith, Sarah; Nazareth, Irwin; Rait, Greta

    2013-01-01

    Background Loss to follow-up from randomised trials can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to reduce loss to follow-up and improve retention but few have been formally evaluated. Objectives To quantify the effect of strategies to improve retention on the proportion of participants retained in randomised trials and to investigate if the effect varied by trial strategy and trial setting. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PreMEDLINE, EMBASE, PsycINFO, DARE, CINAHL, Campbell Collaboration's Social, Psychological, Educational and Criminological Trials Register, and ERIC. We handsearched conference proceedings and publication reference lists for eligible retention trials. We also surveyed all UK Clinical Trials Units to identify further studies. Selection criteria We included eligible retention trials of randomised or quasi-randomised evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance. Data collection and analysis We contacted authors to supplement or confirm data that we had extracted. For retention trials, we recorded data on the method of randomisation, type of strategy evaluated, comparator, primary outcome, planned sample size, numbers randomised and numbers retained. We used risk ratios (RR) to evaluate the effectiveness of the addition of strategies to improve retention. We assessed heterogeneity between trials using the Chi2 and I2 statistics. For main trials that hosted retention trials, we extracted data on disease area, intervention, population, healthcare setting, sequence generation and allocation concealment. Main results We identified 38 eligible retention trials. Included trials evaluated six broad types of strategies to improve retention. These

  20. Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

    SciTech Connect

    Gauglitz, P.A.; Rassat, S.D.; Powell, M.R.

    1995-08-01

    Several of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood. Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles. The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be used in large-scale computations of waste tank physical phenomena.

  1. LARES Mission: Separation and Retention Subsystem

    NASA Technical Reports Server (NTRS)

    Bursi, Alessandro; Camilli, Pierluigi; Piredda, Claudio; Babini, Gianni; Mangraviti, Elio

    2014-01-01

    As part of the Lares (LAser RElativity Satellite) mission, an all-Italian scientific mission launched with the Vega maiden flight in February 2012, a mechanical separation and retention subsystem (SSEP) has been developed to retain the LARES satellite during launch and release it in the final orbit. The design flow was based on the identification of the driving requirements and critical areas to guide the trade-off, design, analysis and test activities. In particular, the SSEP had to face very high environmental loads and to minimize the contact areas with the satellite that had a spherical shape. The test activity overview is provided.

  2. Survey on workforce retention and attrition

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-03-01

    The Society of Petroleum Engineers (SPE) is conducting a survey to gather information on why technical professionals change jobs or quit working. The survey, prompted by concern about the retention of skilled workers, aims to provide information to employers that can assist them in addressing practices that can lead to significant workforce attrition. To participate in the survey, which is open to everyone (including those who are not SPE members), go to http://research.spe.org/se.ashx?s=705E3F1335720258 through 15 May 2013. For more information, contact speresearch@spe.org.

  3. Workforce Challenges and Retention Success Stories

    NASA Technical Reports Server (NTRS)

    Donohue, John T.

    2008-01-01

    This viewgraph document discusses the current and future challenges in building and retaining the required workforce of scientist and engineers for NASA. Specifically, the talk reviews the current situation at the Goddard Space Flight Center in Greenbelt, Maryland. Several programs at NASA for high school and college students to assist in inspiring the next generation of scientist and engineers are reviewed. The issue of retention of the best of the young scientists and engineers is also reviewed, with a brief review of several young engineers and their success with and for NASA.

  4. Strategies to Address Recruiting and Retention Issues in the Military (Strategies pour aborder les questions de recrutement et de fidelisation dans les armees)

    DTIC Science & Technology

    2009-10-01

    Oct 2009 Strategies to Address Recruiting and Retention Issues in the Military (Stratégies pour aborder les questions de recrutement et de...les questions de recrutement et de fidélisation dans les armées) The material in this publication was assembled to support a Special Course under...HFM-180 Stratégies pour aborder les questions de recrutement et de fidélisation dans les armées (RTO-EN-HFM-180) Synthèse L’objectif des

  5. Football and Freshmen Retention: Examining the Impact of College Football on Institutional Retention Rates

    ERIC Educational Resources Information Center

    Jones, Willis A.

    2010-01-01

    Student retention has been one of the more researched topics in the study of American higher education over the past 20 years (Braxton, Hirschy, & McClendon, 2004; Pascarella & Terenzini, 2005). Very little of this research, however, has attempted to examine the impact of college athletics on an institution's ability to retain students.…

  6. Sexual Behaviors in Autism: Problems of Definition and Management.

    ERIC Educational Resources Information Center

    Realmuto, George M.; Ruble, Lisa A.

    1999-01-01

    Explores the problems of definition of sexual behaviors in individuals with autism and describes a case that highlights the difficulties of management. After failure of behavioral and educational programs, a testosterone-suppressing medication was used resulting in suppression of public masturbation behaviors and retention of the participant's…

  7. Modeling structural influences on soil water retention

    USGS Publications Warehouse

    Nimmo, J.R.

    1997-01-01

    A new model quantities the effect of soil structure, considered as the arrangement of particles in the soil, on soil water retention. The model partitions the pore space into texture-related and structure-related components, the textural component being what can be deduced to exist if the arrangement of the particles were random, and the structural component being the remainder. An existing model, based on particle-size distributions, represents the textural component, and a new model, based on aggregate-size distributions, represents the structural component. This new model makes use of generalized properties that vary little from one medium to another, thereby eliminating any need for empirically tilted parameters. It postulates a particular character of the structural pore space that in same ways resembles texture-related pore space, but with pore shape related to the breadth of the aggregate-size distribution. To predict a soil water retention curve, this model requires the soil's porosity and particle- and aggregate-size distributions. Tested with measurements for 17 samples from two sources, it fits the data much better than does a model based on texture alone. Goodness of fit indicated by correlation coefficients ranged from 0.908 to 0.998 for the new model, compared with a range of 0.686 in 0.955 for the texture-based model.

  8. Radionuclide Retention in Concrete Waste Forms

    SciTech Connect

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  9. Global phosphorus retention by river damming

    PubMed Central

    Maavara, Taylor; Parsons, Christopher T.; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H.; Powley, Helen R.; Van Cappellen, Philippe

    2015-01-01

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y−1, or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions. PMID:26644553

  10. Radionuclide Retention in Concrete Wasteforms - FY13

    SciTech Connect

    Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

    2013-10-15

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  11. Hydrogen retention in ion irradiated steels

    SciTech Connect

    Hunn, J.D.; Lewis, M.B.; Lee, E.H.

    1998-11-01

    In the future 1--5 MW Spallation Neutron Source, target radiation damage will be accompanied by high levels of hydrogen and helium transmutation products. The authors have recently carried out investigations using simultaneous Fe/He,H multiple-ion implantations into 316 LN stainless steel between 50 and 350 C to simulate the type of radiation damage expected in spallation neutron sources. Hydrogen and helium were injected at appropriate energy and rate, while displacement damage was introduced by nuclear stopping of 3.5 MeV Fe{sup +}, 1 {micro}m below the surface. Nanoindentation measurements showed a cumulative increase in hardness as a result of hydrogen and helium injection over and above the hardness increase due to the displacement damage alone. TEM investigation indicated the presence of small bubbles of the injected gases in the irradiated area. In the current experiment, the retention of hydrogen in irradiated steel was studied in order to better understand its contribution to the observed hardening. To achieve this, the deuterium isotope ({sup 2}H) was injected in place of natural hydrogen ({sup 1}H) during the implantation. Trapped deuterium was then profiled, at room temperature, using the high cross-section nuclear resonance reaction with {sup 3}He. Results showed a surprisingly high concentration of deuterium to be retained in the irradiated steel at low temperature, especially in the presence of helium. There is indication that hydrogen retention at spallation neutron source relevant target temperatures may reach as high as 10%.

  12. Retention of Halogens in Waste Glass

    SciTech Connect

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  13. Cooking utensil with improved heat retention

    DOEpatents

    Potter, T.F.; Benson, D.K.; Burch, S.D.

    1997-07-01

    A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber there between. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food. 26 figs.

  14. Cooking utensil with improved heat retention

    DOEpatents

    Potter, Thomas F.; Benson, David K.; Burch, Steven D.

    1997-01-01

    A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber therebetween. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food.

  15. Practical solutions for staff recruitment & retention.

    PubMed

    Vander Hoek, N

    2001-01-01

    There are three essential topics for radiology managers to consider in light of persistent staffing shortages: support of the profession and educational programs, perks as recruitment tools and incentives as retention tools. Some activities that can help support departments and educational programs for radiologic technologists are job shadowing, training for volunteer services, advanced placement for school applicants, sponsoring an educational program or clinical training site, creating a positive work environment and supporting outreach projects geared to local high schools. Traditional perks used in recruitment efforts have included relocation assistance, travel and lodging expenses during the interview process, loan repayment, scholarships and sign-on bonuses. Some common incentives for retaining employees are tuition reimbursement, cross training, availability of educational resources, continuing education opportunities, professional development and incremental increases in salary. There are many other tools that can be used, such as career ladders, creating an environment conducive to teamwork or a more personal atmosphere and showcasing talents of various staff members. There is much overlap among these suggestions in support of the profession and educational programs, recruitment and retention of qualified staff radiologic technologists. Radiology managers can and should be creative in developing different programs to build loyalty and commitment to a radiology department.

  16. Permeability and Retentivity Curves In Mountain Soils

    NASA Astrophysics Data System (ADS)

    Barontini, S.; Ranzi, R.

    The saturated conductivity, Ks, and the retentivity curves, for mountain non-mature soils have been determined after laboratory- and field-experiments carried out over about 146 soil samples in the Toce river basin (Val d'Ossola, Northern Italian Alps). Eightythree samples only have been used to measure the retentivity curves using 15 bar and 5 bar Richard's extractors. Coherently with other researches, traditional meth- ods used to derive Ks on the basis of in situ infiltration test with a single ring infiltrom- eter provided values grater than those calculated using a variable head permeameter in laboratory. So other simplified methods have been used to estimate Ks after field analysis: the traditional method based on the Darcy's law, modified in respect of soil saturation; a method based on an application of Green and Ampt infiltration model; and a method based on the Wooding's works. All these methods, in particular the Wooding (1968) solution, gave estimates of Ks closer to the laboratory ones and to the results of a finite elements numerical solution of the Richard's equation in a 3D domain with axial simmetry. As a result an updated legend for the existing surface soil saturated conductivity map for the of the Toce basin is proposed. Inhomogeneities in the vertical permeability profiles have been identified also.

  17. Uterine Fibroid (Leiomyoma) with Acute Urinary Retention: A Case Series.

    PubMed

    Singh, Sweta; Jena, Saubhagya Kumar; Naik, Monalisha; Ray, Lipsa; Behera, Satyanarayan

    2016-04-01

    Uterine leiomyomas are an extremely rare cause of acute urinary retention in women. The delay in diagnosing uterine leiomyomas presenting with acute urinary retention further complicates the management. The rarity of the condition makes it difficult to plan either prospective or retrospective trials. Hence, most of the evidence comes from case reports or series. We report a case series of acute urinary retention in women with uterine leiomyomas and discuss the pathophysiology, diagnosis and management options.

  18. Uterine Fibroid (Leiomyoma) with Acute Urinary Retention: A Case Series

    PubMed Central

    Jena, Saubhagya Kumar; Naik, Monalisha; Ray, Lipsa; Behera, Satyanarayan

    2016-01-01

    Uterine leiomyomas are an extremely rare cause of acute urinary retention in women. The delay in diagnosing uterine leiomyomas presenting with acute urinary retention further complicates the management. The rarity of the condition makes it difficult to plan either prospective or retrospective trials. Hence, most of the evidence comes from case reports or series. We report a case series of acute urinary retention in women with uterine leiomyomas and discuss the pathophysiology, diagnosis and management options. PMID:27190903

  19. Learning communities: the link to recruitment and retention.

    PubMed

    Bassi, Sherry; Polifroni, E Carol

    2005-01-01

    The professional learning community is a strategy to help staff development educators address recruitment and retention and organizational culture. The purpose of this article is to analyze the concept of learning communities and discuss their potential to increase the recruitment and retention of new graduate nurses and returning practitioners to the nursing profession. Incorporating learning communities into the healthcare organization will decrease the number of nurses leaving nursing, foster retention, and thus, enhance recruitment.

  20. Retention of Digital Skills: Command Post of the Future

    DTIC Science & Technology

    2011-01-01

    Social Sciences. NOTE: The findings in this Research Report are not to be construed as an official Department of the Army position, unless so...among the patterns of individual-skill retention were found. In addition, differences were found in CPOF-skill retention across types of skills. The...pattern of retention was then used to identify the specific skills and the progression of skills that are critical in developing CPOF expertise. 15

  1. Job embeddedness as a nurse retention strategy for rural hospitals.

    PubMed

    Stroth, Chandra

    2010-01-01

    RN turnover is expensive and disruptive for rural hospitals, constraining finances, impacting patient care, and stressing remaining nurses. Recent investigations have described a promising new construct related to employee retention: job embeddedness. Leaders in nonhealthcare organizations have adopted a job-embeddedness model to guide retention strategies and experienced a subsequent reduction in turnover. The author explores job embeddedness as an effective retention plan strategy for rural hospitals.

  2. Simulation study on retention and reflection from tungsten carbide under high fluence of helium ions

    NASA Astrophysics Data System (ADS)

    Ono, T.; Kawamura, T.; Kenmotsu, T.; Yamamura, Y.

    2001-03-01

    We have studied, with a Monte Carlo simulation code ACAT-DIFFUSE, the fluence-dependence of the amount of helium atoms retained in tungsten carbide at room temperature under helium ion bombardment. The retention behavior may be understood qualitatively in terms of irradiation-dependent diffusion coefficient assumed and range. The re-emission, reflection and sputtering from tungsten carbide under helium ion irradiation were derived and compared with each other. We have discussed the retention curves for incident energy of 5 keV at incident angles of 0° and 80° and of 500 eV at 0°. The energy spectra of helium atoms reflected from tungsten carbide for incident energy of 500 eV at 0° and 80° were compared with those from graphite and tungsten.

  3. Effects of Globally Waste Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks

    SciTech Connect

    Stewart, Charles W.; Fountain, Matthew S.; Huckaby, James L.; Mahoney, Lenna A.; Meyer, Perry A.; Wells, Beric E.

    2005-08-02

    Various operations are authorized in Hanford single- and double-shell tanks that disturb all or a large fraction of the waste. These globally waste-disturbing activities have the potential to release a large fraction of the retained flammable gas and to affect future gas generation, retention, and release behavior. This report presents analyses of the expected flammable gas release mechanisms and the potential release rates and volumes resulting from these activities. The background of the flammable gas safety issue at Hanford is summarized, as is the current understanding of gas generation, retention, and release phenomena. Considerations for gas monitoring and assessment of the potential for changes in tank classification and steady-state flammability are given.

  4. Synthesis and performances of polycarboxylate superplaticizer with clay-inerting and high slump retention capability

    NASA Astrophysics Data System (ADS)

    Qian, Shanshan; Jiang, Haidong; Ding, Bei; Wang, Yi; Zheng, Chunyang; Guo, Zhaolai

    2017-03-01

    Macromolecules with pendant chlorine groups on their main chains were synthesized via free-radical copolymerization of 2-hydroxyethyl acrylate(HEA), TPEG and vinylbenzyl chloride(VBC) in the presence of intiator and chain transfer agent according to molecular structure design principle. The subsequent Arbuzov reaction between trimethoxyphosphine(TMP) and chlorine groups of macromolecules(PHVT) gave rise to new type of polycarboxylate superplaticizer with clay-inerting and high slump retention capability. The molecular structure of superplasticizer was determined by Fourier Transform Infrared Spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC), respectively. The adaptability of clays, Zata potential, adsorption behavior and application performance in concrete were measured. The results shows that the polycarboxylate superplaticizer we prepared has good clay compatibility, excellent clay-inerting and high slump retention capability.

  5. Rayleigh-Taylor Instability within Sediment Layers Due to Gas Retention: Preliminary Theory and Experiments

    SciTech Connect

    Gauglitz, Phillip A.; Wells, Beric E.; Buchmiller, William C.; Rassat, Scot D.

    2013-03-21

    In Hanford underground waste storage tanks, a typical waste configuration is settled beds of waste particles beneath liquid layers. The settled beds are typically composed of layers, and these layers can have different physical and chemical properties. One postulated configuration within the settled bed is a less-dense layer beneath a more-dense layer. The different densities can be a result of different gas retention in the layers or different degrees of settling and compaction in the layers. This configuration can experience a Rayleigh-Taylor (RT) instability where the less dense lower layer rises into the upper layer. Previous studies of gas retention and release have not considered potential buoyant motion within a settle bed of solids. The purpose of this report is to provide a review of RT instabilities, discuss predictions of RT behavior for sediment layers, and summarize preliminary experimental observations of RT instabilities in simulant experiments.

  6. Human memory retention and recall processes. A review of EEG and fMRI studies.

    PubMed

    Amin, Hafeezullah; Malik, Aamir S

    2013-10-01

    Human memory is an important concept in cognitive psychology and neuroscience. Our brain is actively engaged in functions of learning and memorization. Generally, human memory has been classified into 2 groups: short-term/working memory, and long-term memory. Using different memory paradigms and brain mapping techniques, psychologists and neuroscientists have identified 3 memory processes: encoding, retention, and recall. These processes have been studied using EEG and functional MRI (fMRI) in cognitive and neuroscience research. This study reviews previous research reported for human memory processes, particularly brain behavior in memory retention and recall processes with the use of EEG and fMRI. We discuss issues and challenges related to memory research with EEG and fMRI techniques.

  7. Retention performance of green roofs in three different climate regions

    NASA Astrophysics Data System (ADS)

    Sims, Andrew W.; Robinson, Clare E.; Smart, Charles C.; Voogt, James A.; Hay, Geoffrey J.; Lundholm, Jeremey T.; Powers, Brandon; O'Carroll, Denis M.

    2016-11-01

    Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier climates were found to have greater percent cumulative stormwater retention with Calgary (67%) having significantly better percent retention than both London (48%) and Halifax (34%). However, over the same study period the green roof in London retained the greatest depth of stormwater (598 mm), followed by the green roof in Halifax (471 mm) and then Calgary (411 mm). The impact of climate was largest for medium sized storms where the antecedent moisture condition (AMC) at the beginning of a rainfall event governs retention performance. Importantly AMC was a very good predictor of stormwater retention, with similar retention at all three sites for a given AMC, emphasizing that AMC is a relevant indicator of retention performance in any climate. For large rainfall events (i.e., >45 mm) green roof average retention ranged between 16% and 29% in all cities. Overall, drier climates have superior retention due to lower AMC in the media. However, moderate and wet climates still provide substantial total volume reduction benefits.

  8. Secondary retention of rubber dam: effective moisture control access considerations.

    PubMed

    Liebenberg, W H

    1995-04-01

    Primary rubber dam retention affects attachment of the latex sheet to the anchor teeth bordering the isolated working field. Secondary rubber dam retention is the provision of an effective seal at the dam-tooth junction, which is essential to the maintenance of adequate access and moisture control within the working field. Practical hints are offered to optimize access and moisture control through well-planned and properly executed secondary retention of classic rubber dam applications. In addition, innovative solutions to the limitations of general field isolation, which pertain mostly to secondary retention of the unrestrained buccal and lingual curtains of the slit dam, are introduced.

  9. Reliability of the retention factor estimations in liquid chromatography.

    PubMed

    Escuder-Gilabert, L; Bermúdez-Saldaña, J M; Villanueva-Camañas, R M; Medina-Hernández, M J; Sagrado, S

    2004-04-16

    The retention factor is one of the most universally used parameters in chromatography. However, large differences in the experimental retention factor values are observed when the same compound is injected in a given stationary/mobile phase system under intermediate precision conditions. Conventional protocols for estimating retention factors have problems that mainly arise from difficulties in the hold-up time measurements and the omission of the existence of extra-column times by practicing chromatographers. In the present paper, three different approaches for estimating retention factors are tested: (i) classical retention factor estimations based on the gross hold-up time, (ii) based on the real hold-up time (taking into account the extra-column time), and (iii) a new approach that uses 'relative' retention factors based on the use of an external standard. Assays are performed in micellar liquid chromatography (MLC) under intermediate precision conditions (different days, equipments, columns lengths, and mobile phase flow rates). The reliability of the three approaches tested is evaluated by means of precision studies, analysis of factors affecting retention factors, and uncertainty calculations. The approach based on 'relative' retention factors was found to be the most precise, reliable, and robust strategy for estimating retention factors.

  10. 21 CFR 320.63 - Retention of bioequivalence samples.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.63 Retention of bioequivalence...

  11. Permanent ferroelectric retention of BiFeO3 mesocrystal

    PubMed Central

    Hsieh, Ying-Hui; Xue, Fei; Yang, Tiannan; Liu, Heng-Jui; Zhu, Yuanmin; Chen, Yi-Chun; Zhan, Qian; Duan, Chun-Gang; Chen, Long-Qing; He, Qing; Chu, Ying-Hao

    2016-01-01

    Non-volatile electronic devices based on magnetoelectric multiferroics have triggered new possibilities of outperforming conventional devices for applications. However, ferroelectric reliability issues, such as imprint, retention and fatigue, must be solved before the realization of practical devices. In this study, everlasting ferroelectric retention in the heteroepitaxially constrained multiferroic mesocrystal is reported, suggesting a new approach to overcome the failure of ferroelectric retention. Studied by scanning probe microscopy and transmission electron microscopy, and supported via the phase-field simulations, the key to the success of ferroelectric retention is to prevent the crystal from ferroelastic deformation during the relaxation of the spontaneous polarization in a ferroelectric nanocrystal. PMID:27782123

  12. Conceptual classification model for Sustainable Flood Retention Basins.

    PubMed

    Scholz, Miklas; Sadowski, Adam J

    2009-01-01

    The aim of this paper is to recommend a rapid conceptual classification model for Sustainable Flood Retention Basins (SFRB) used to control runoff in a temperate climate. An SFRB is an aesthetically pleasing retention basin predominantly used for flood protection adhering to sustainable drainage and best management practices. The classification model was developed on the basis of a database of 141 SFRB using the River Rhine catchment in Baden (part of Baden-Württemberg, Germany) as a case study. It is based on an agglomerative cluster analysis and is intended to be used by engineers and scientists to adequately classify the following different types of SFRB: Hydraulic Flood Retention Basin, Traditional Flood Retention Basin, Sustainable Flood Retention Wetland, Aesthetic Flood Retention Wetland, Integrated Flood Retention Wetland and Natural Flood Retention Wetland. The selection of classification variables was supported by a principal component analysis. The identification of SFRB in the data set was based on a Ward cluster analysis of 34 weighted classification variables. Scoring tables were defined to enable the assignment of the six SFRB definitions to retention basins in the data set. The efficiency of these tables was based on a scoring system which gave the conceptual model for the example case study sites an overall efficiency of approximately 60% (as opposed to 17% by chance). This conceptual classification model should be utilized to improve communication by providing definitions for SFRB types. The classification definitions are likely to be applicable for other regions with both temperate oceanic and temperate continental climates.

  13. Maternal weight change between 1 and 2 years postpartum: the importance of 1 year weight retention.

    PubMed

    Lipsky, Leah M; Strawderman, Myla S; Olson, Christine M

    2012-07-01

    Pregnancy weight gain may lead to long-term increases in maternal BMI for some women. The objective of this study was to examine maternal body weight change 1y-2y postpartum, and to compare classifications of 2y weight retention with and without accounting for 1y-2y weight gain. Early pregnancy body weight (EPW, first trimester) was measured or imputed, and follow-up measures obtained before delivery, 1 year postpartum (1y) and 2 years postpartum (2y) in an observational cohort study of women seeking prenatal care in several counties in upstate New York (n = 413). Baseline height was measured; demographic and behavioral data were obtained from questionnaires and medical records. Associations of 1y-2y weight change (kg) and 1y-2y weight gain (≥2.25 kg) with anthropometric, socioeconomic, and behavioral variables were evaluated using linear and logistic regressions. While mean ± SE 1y-2y weight change was 0.009 ± 4.6 kg, 1y-2y weight gain (≥2.25 kg) was common (n = 108, 26%). Odds of weight gain 1y-2y were higher for overweight (OR(adj) = 2.63, CI(95%) = 1.43-4.82) and obese (OR(adj) = 2.93, CI(95%) = 1.62-5.27) women than for women with BMI <25. Two year weight retention (2y-EPW ≥2.25 kg) was misclassified in 38% (n = 37) of women when 1y-2y weight gain was ignored. One year weight retention (1YWR) (1y-EPW) was negatively related to 1y-2y weight change (β(adj) ± SE = -0.28 ± 0.04, P < 0.001) and weight gain (≥2.25 kg) (OR(adj) = 0.91, CI(95%) = 0.87-0.95). Relations between 1y weight retention and 1y-2y weight change were attenuated for women with higher early pregnancy BMI. Weight change 1y-2y was predicted primarily by an inverse relation with 1y weight retention. The high frequency of weight gain has important implications for classification of postpartum weight retention.

  14. Positionsbestimmung des Unternehmens: Interne und externe Analyse

    NASA Astrophysics Data System (ADS)

    Bergmann, Lars; Crespo, Isabel; Portmann, Stefan

    Die Initiierung und Lenkung von Maßnahmen zur integrierten Modernisierung zielen auf die Verbesserung der Wettbewerbsfähigkeit eines Unternehmens ab. Damit diese Maßnahmen zielgerichtet die Wettbewerbsfähigkeit verbessern können, ist Wissen über die bestehende Wettbewerbsfähigkeit sowie über die bestehenden Fähigkeiten eine zentrale Voraussetzung. Eine zielgerichtete Auswahl problemadäquater Maßnahmen zur Verbesserung der Wettbewerbsfähigkeit bedarf daher im Vorfeld einer Bewertung der aktuellen Situation des Unternehmens im Sinne einer Positionsbestimmung. Erst wenn die internen Stärken und Schwächen sowie die externen Chancen und Risiken identifiziert sind, kann ein ganzheitliches Bild von der Position eines Unternehmens in seiner Umwelt gewonnen werden. Auf Basis der Kenntnisse über die Position des Unternehmens können anschließend zielgerichtet Maßnahmen ausgewählt werden, die einen Beitrag zur Verbesserung der Wettbewerbsfähigkeit des Unternehmens haben. Damit kommt der Positionsbestimmung als initialer Schritt des Prozesses der strategischen Unternehmensplanung eine zentrale Bedeutung im Rahmen der integrierten Modernisierung zu. Erfolgt die Auswahl von Maßnahmen ohne eine vorherige Positionsbestimmung, also lediglich auf Basis drängender Probleme, so besteht die Gefahr einer unbedachten und nur auf das "hier und heute“ bezogenen Schwerpunktbildung ohne Berücksichtigung der mittel- und langfristigen Ziele des Unternehmens.

  15. Associative Learning during Early Adulthood Enhances Later Memory Retention in Honeybees

    PubMed Central

    Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

    2009-01-01

    Background Cognitive experiences during the early stages of life play an important role in shaping the future behavior in mammals but also in insects, in which precocious learning can directly modify behaviors later in life depending on both the timing and the rearing environment. However, whether olfactory associative learning acquired early in the adult stage of insects affect memorizing of new learning events has not been studied yet. Methodology Groups of adult honeybee workers that experienced an odor paired with a sucrose solution 5 to 8 days or 9 to 12 days after emergence were previously exposed to (i) a rewarded experience through the offering of scented food, or (ii) a non-rewarded experience with a pure volatile compound in the rearing environment. Principal Findings Early rewarded experiences (either at 1–4 or 5–8 days of adult age) enhanced retention performance in 9–12-day-conditioned bees when they were tested at 17 days of age. The highest retention levels at this age, which could not be improved with prior rewarded experiences, were found for memories established at 5–8 days of adult age. Associative memories acquired at 9–12 days of age showed a weak effect on retention for some pure pre-exposed volatile compounds; whereas the sole exposure of an odor at any younger age did not promote long-term effects on learning performance. Conclusions The associative learning events that occurred a few days after adult emergence improved memorizing in middle-aged bees. In addition, both the timing and the nature of early sensory inputs interact to enhance retention of new learning events acquired later in life, an important matter in the social life of honeybees. PMID:19956575

  16. Psychometric Evaluation and Cultural Correlates of the Mate Retention Inventory-Short Form (MRI-SF) in Iran.

    PubMed

    Atari, Mohammad; Barbaro, Nicole; Shackelford, Todd K; Chegeni, Razieh

    2017-01-01

    The current study investigated the psychometric properties of the Persian translation of the Mate Retention Inventory-Short Form (MRI-SF) in Iran. We also investigated sex differences in the use of mate retention tactics and investigated the relationships between mate retention behaviors and a number of related cultural constructs. Participants ( N = 308) ranged in age from 18 to 57 years. All participants were in a committed romantic relationship, with mean relationship length of 63.5 months ( SD = 73.8). Participants completed the Persian translation of the MRI-SF and measures of religiosity, relationship satisfaction, self-esteem, and socioeconomic status. Cultural measures specific to Iran were also included, such as Mahr (for married individuals), self-perceived Qeiratiness (for men), and self-perceived jealousy (for women). Mahr is a mandatory amount of money or possessions paid or promised to be paid by the groom to the bride at the time of the marriage contract. Qeirati is a male-specific adjective in Persian meaning protective against unwanted attention toward a man's romantic partner. Female jealousy is usually regarded the counterpart of male Qeiratiness in Iranian culture. The 19 mate retention tactics formed a two-component structure, consistent with previous research. Results demonstrate adequate internal consistency of 2-item assessments of mate retention tactics. Observed sex differences accorded with previous mate retention research and are discussed in reference to evolutionary perspectives on human mating. Several significant associations emerged between mate retention tactics and Iranian culture-specific variables and are discussed from a cross-cultural perspective.

  17. Scoring Dawg Core Breakoff and Retention Mechanism

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Backes, Paul G.

    2011-01-01

    This novel core break-off and retention mechanism consists of a scoring dawg controlled by a set of two tubes (a drill tube and an inner tube). The drill tube and the inner tube have longitudinal concentric holes. The solution can be implemented in an eccentric tube configuration as well where the tubes have eccentric longitudinal holes. The inner tube presents at the bottom two control surfaces for controlling the orientation of the scoring dawg. The drill tube presents a sunk-in profile on the inside of the wall for housing the scoring dawg. The inner tube rotation relative to the drill tube actively controls the orientation of the scoring dawg and hence its penetration and retrieval from the core. The scoring dawg presents a shaft, two axially spaced arms, and a tooth. The two arms slide on the control surfaces of the inner tube. The tooth, when rotated, can penetrate or be extracted from the core. During drilling, the two tubes move together maintaining the scoring dawg completely outside the core. After the desired drilling depth has been reached the inner tube is rotated relative to the drill tube such that the tooth of the scoring dawg moves toward the central axis. By rotating the drill tube, the scoring dawg can score the core and so reduce its cross sectional area. The scoring dawg can also act as a stress concentrator for breaking the core in torsion or tension. After breaking the core, the scoring dawg can act as a core retention mechanism. For scoring, it requires the core to be attached to the rock. If the core is broken, the dawg can be used as a retention mechanism. The scoring dawg requires a hard-tip insert like tungsten carbide for scoring hard rocks. The relative rotation of the two tubes can be controlled manually or by an additional actuator. In the implemented design solution the bit rotation for scoring was in the same direction as the drilling. The device was tested for limestone cores and basalt cores. The torque required for breaking the

  18. Retention in HIV care among female sex workers in the Dominican Republic: implications for research, policy and programming.

    PubMed

    Zulliger, Rose; Maulsby, Cathy; Barrington, Clare; Holtgrave, David; Donastorg, Yeycy; Perez, Martha; Kerrigan, Deanna

    2015-04-01

    There are clear benefits of retention in HIV care, yet millions of people living with HIV are sub-optimally retained. This study described factors from Andersen's behavioral model that were associated with retention in HIV care among 268 female sex workers (FSWs) living with HIV in the Dominican Republic using two measures of retention: a 6-month measure of HIV clinic attendance and a measure that combined clinic attendance and missed visits. FSWs who ever attended HIV care reported high rates (92 %) of 6-month attendance, but 37 % reported missed visits. Using the combined retention measure, the odds of being retained in HIV care were higher among FSWs with more positive perceptions of HIV service providers [adjusted odds ratio (AOR) 1.17; 95 % confidence interval (CI) 01.09, 1.25] and lower among women who reported recent alcohol consumption (AOR 0.50; 95 % CI 0.28, 0.92) and self-stigmatizing beliefs related to sex work (AOR 0.93; 95 % CI 0.88, 0.98). These findings support the hypothesis that retention in HIV care may be best determined through a combined measure as missed visits are an important mechanism to identify in-care patients who require additional support.

  19. Cross-Correlating DES and SPT

    NASA Astrophysics Data System (ADS)

    Baxter, Eric

    2017-01-01

    The Dark Energy Survey (DES) and the South Pole Telescope (SPT) provide a uniquely powerful combination of overlapping optical imaging and cosmic microwave background (CMB) data. Cross-correlations between DES and SPT are expected to arise from several physical effects, including gravitational lensing, the Sunyaev-Zel'dovich (SZ) effect, and the Integrated Sachs-Wolfe effect. The resultant correlations contain information not accessible to either experiment on its own. Measurement of these correlations offers several exciting possibilities, such as improved cosmological parameter constraints, improved understanding of systematics affecting the two experiments, and calibration of the masses of galaxy clusters at high redshift. In this talk I will summarize recent results obtained by cross-correlating early DES data with data from the SPT-SZ survey and will discuss prospects for future cross-correlation measurements with these two surveys.

  20. Dynamic DDES On DES Type Grid

    NASA Astrophysics Data System (ADS)

    Yin, Zifei; Durbin, Paul

    2014-11-01

    A dynamic procedure allows a DES formulation that we developed to adjustCDES for different flow configurations. Similarly to the dynamic Smagorinsky model, the grid is required to be fine enough to resolve a significant portion of the inertial range. In some cases, that requirement conflicts with the goal of DES to cut down computing cost. The current effort is therefore to determine a properCDES value by approximately recovering some unresolved small scales from primary, filtered solution. Repeated test filtering is adopted here to compute the approximation of the unfiltered solution. The formulation is based on the dynamicl2 w DDES model and different geometries with varies grid resolution are tested to determine the applicability of proposed formultion on DES type grids.

  1. Novel word retention in bilingual and monolingual speakers

    PubMed Central

    Kan, Pui Fong; Sadagopan, Neeraja

    2014-01-01

    The goal of this research was to examine word retention in bilinguals and monolinguals. Long-term word retention is an essential part of vocabulary learning. Previous studies have documented that bilinguals outperform monolinguals in terms of retrieving newly-exposed words. Yet, little is known about whether or to what extent bilinguals are different from monolinguals in word retention. Participants were 30 English-speaking monolingual adults and 30 bilingual adults who speak Spanish as a home language and learned English as a second language during childhood. In a previous study (Kan et al., 2014), the participants were exposed to the target novel words in English, Spanish, and Cantonese. In this current study, word retention was measured a week after the fast mapping task. No exposures were given during the one-week interval. Results showed that bilinguals and monolinguals retain a similar number of words. However, participants produced more words in English than in either Spanish or Cantonese. Correlation analyses revealed that language knowledge plays a role in the relationships between fast mapping and word retention. Specifically, within- and across-language relationships between bilinguals' fast mapping and word retention were found in Spanish and English, by contrast, within-language relationships between monolinguals' fast mapping and word retention were found in English and across-language relationships between their fast mapping and word retention performance in English and Cantonese. Similarly, bilinguals differed from monolinguals in the relationships among the word retention scores in three languages. Significant correlations were found among bilinguals' retention scores. However, no such correlations were found among monolinguals' retention scores. The overall findings suggest that bilinguals' language experience and language knowledge most likely contribute to how they learn and retain new words. PMID:25324789

  2. Dynamic fuel retention in tokamak wall materials: An in situ laboratory study of deuterium release from polycrystalline tungsten at room temperature

    NASA Astrophysics Data System (ADS)

    Bisson, R.; Markelj, S.; Mourey, O.; Ghiorghiu, F.; Achkasov, K.; Layet, J.-M.; Roubin, P.; Cartry, G.; Grisolia, C.; Angot, T.

    2015-12-01

    Retention of deuterium ion implanted in polycrystalline tungsten samples is studied in situ in an ultra-high vacuum apparatus equipped with a low-flux ion source and a high sensitivity thermo-desorption setup. Retention as a function of ion fluence was measured in the 1017-1021 D+·m-2 range. By combining this new fluence range with the literature in situ experimental data, we evidence the existence of a retention ∝ fluence0.645±0.025 relationship which describes deuterium retention behavior on polycrystalline tungsten on 8 orders of magnitude of fluence. Evolution of deuterium retention as a function of the sample storage time in vacuum at room temperature was followed. A loss of 50% of the retained deuterium is observed when the storage time is increased from 2 h to 135 h. The role of the surface and of natural bulk defects on the deuterium retention/release in polycrystalline tungsten is discussed in light of the behavior of the single desorption peak obtained with Temperature Programmed Desorption.

  3. Formation and retention of methane in coal. Final report

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  4. Recruitment and Retention of LGBTIQ Astronomers

    NASA Astrophysics Data System (ADS)

    Dixon, William Van Dyke

    2012-01-01

    While lesbian, gay, bisexual, transgender, intersex, or questioning (LGBTIQ) astronomers face many of the same workplace challenges as women and racial/ethnic minorities, from implicit bias to overt discrimination, other challenges are unique to this group. An obvious example is the absence at many institutions of health insurance and other benefits for the same-sex domestic partners of their employees. More subtle is the psychological toll paid by LGBTIQ astronomers who remain "in the closet," self-censoring every statement about their personal lives. Paradoxically, the culture of the physical sciences, in which sexuality, gender identity, and gender expression are considered irrelevant, can discourage their discussion, further isolating LGBTIQ researchers. Addressing these challenges is not just a matter of fairness; it is an essential tool in the recruitment and retention of the brightest researchers and in assuring their productivity. We will discuss these issues and what individuals and departments can to make their institutions more welcoming to their LGBTIQ colleagues.

  5. Managing and Preventing Acute Urinary Retention

    PubMed Central

    Lepor, Herbert

    2005-01-01

    Acute urinary retention (AUR), an uncomfortable and potentially dangerous condition, often occurs in men who have benign prostatic hyperplasia. Although the reported incidence of AUR varies in the literature, there are a number of events that are known to precipitate episodes of AUR, including ingestion of certain agents, infection, general anesthesia, and performance of various diagnostic genitourinary procedures. Because it is preferable to avoid the need for catheterization (and the associated risks) in men at high risk for AUR, certain measures have been studied as means to prevent AUR episodes. Specifically, α-blockers and 5-α-reductase inhibitors have been shown to reduce the incidence of initial and subsequent AUR episodes in certain at-risk men. PMID:16985887

  6. Retention of Cationic Starch onto Cellulose Fibres

    NASA Astrophysics Data System (ADS)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  7. Retention of Compounding Skills Among Pharmacy Students

    PubMed Central

    Eley, John G.; Birnie, Christine

    2006-01-01

    Objective To evaluate the competency of second-year pharmacy students to compound capsules from a prescription 12 months after completing a compounding course. Methods Students who completed the compounding course were given the same prescription they had been given 12 months earlier to compound metoprolol capsules. No warning of the second exercise was given and they were expected to prepare capsules and package and label the finished product. Performance was evaluated in an identical manner for both exercises based on the level of professional competency of a score of 80% or above. Results Eighty-seven percent fewer students achieved a score of 90% or more on the second exercise and 81% fewer students demonstrated the required competency. Conclusions Differences in scores on the first and second exercises indicate that pharmacy students’ level of competency and retention of knowledge with respect to compounding capsules is not adequately retained after a 12-month hiatus. PMID:17332858

  8. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  9. Volatile species retention during metallic fuel casting

    NASA Astrophysics Data System (ADS)

    Fielding, Randall S.; Porter, Douglas L.

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  10. Building 310 retention tanks characterization report

    SciTech Connect

    Sholeen, C.M.; Geraghty, D.C.

    1996-12-01

    The Health Physics Section of ANL performed a characterization of the Building 310 Service Floor Retention Tank Facility during the months of July and August, 1996. The characterization included measurements for radioactivity, air sampling for airborne particles and sampling to determine the presence and quantity of hazardous materials requiring remediation. Copies of previous lead and asbestos sampling information was obtained from ESH-IH. The facility consists of ten retention tanks located in rooms, A-062A, A-050A, A-038A, A-026A, and an entry room A-068A which contained miscellaneous pumps and other scrap material. Significant contamination was found in each room except room A-068A which had two contaminated spots on the floor and a discarded contaminated pump. Room A-062A: This room had the highest radiation background. Therefore, beta readings reflected the background readings. The floor, west wall, and the exterior of tank No. 1 had areas of alpha contamination. The piping leading from the tank had elevated gamma readings. There were low levels of smearable contamination on the west wall-Room A-050A: Alpha and Beta contamination is wide spread on the floor, west wall and the lower portion of the north wall. An area near the electrical box on the west wall had alpha and beta loose contamination. The exterior of tank No. 4 also had contaminated areas. The grate in front of tank No. 4 was contaminated. The piping leading from tanks No. 2, 3, and 4 had elevated gamma readings. There were low levels of smearable contamination on tank No. 4 and on the tar paper that is glued to the floor.

  11. NASA records retention schedules: Procedures governing the retention, retirement, and destruction of agency records

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This handbook sets forth the minimum retention periods of official records of NASA. Its provisions are applicable to NASA Headquarters and all field installations. This revised edition has been correlated to the 'NASA Uniform Files Index (UFI) (NHB 1442.1B), the General Records Schedules' produced by the National Archives and Records Administration (NARA), and has been enlarged in scope to cover Privacy Act Systems of Records and record series previously omitted. Guidance is provided in the areas of record retirement, transfer, and retrieval from Federal Record Centers (FRC) and disposal actions. Included are provisions for making changes to these schedules by addition of new items or revision of current items. The NASA Records Retention Schedules (NRRS) were approved for NASA use by NARA, the General Services Administration, and the General Accounting Office.

  12. 39 CFR 262.6 - Retention and disposal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Retention and disposal. 262.6 Section 262.6 Postal Service UNITED STATES POSTAL SERVICE ORGANIZATION AND ADMINISTRATION RECORDS AND INFORMATION MANAGEMENT DEFINITIONS § 262.6 Retention and disposal. (a) Records control schedule. A directive describing...

  13. Recruitment and Retention of Latino Children in a Lifestyle Intervention

    ERIC Educational Resources Information Center

    Guzman, Angelica; Richardson, Irma M.; Gesell, Sabina; Barkin, Shari L.

    2009-01-01

    Objective: To describe promising recruitment and retention strategies for transient Latino populations, assisting investigators who work with this population in their research design and implementation. Methods: Strategies in recruitment and retention from a year-long intervention in children and their families are described. Results: Of the 159…

  14. What Works in Student Retention? All Survey Colleges

    ERIC Educational Resources Information Center

    Habley, Wesley R.; McClanahan, Randy

    2004-01-01

    This report reflects ACT's commitment to assist colleges and universities to better understand the impact of campus practices on college student retention and degree completion. Survey findings indicate that: (1) Only 51.7% of campuses have identified an individual responsible for coordinating retention strategies; (2) Only 47.2% of campuses have…

  15. Student Variables that Predict Retention: Recent Research and New Developments

    ERIC Educational Resources Information Center

    Reason, Robert D.

    2009-01-01

    This article reviews recent research related to the study of college student retention, specifically examining research related to individual student demographic characteristics. The increasing diversity of undergraduate college students requires a new, thorough examination of those student variables previously understood to predict retention. The…

  16. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  17. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  18. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  19. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  20. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  1. 12 CFR 230.9 - Enforcement and record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Enforcement and record retention. 230.9 Section 230.9 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRUTH IN SAVINGS (REGULATION DD) § 230.9 Enforcement and record retention. (a)...

  2. 12 CFR 707.9 - Enforcement and record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Enforcement and record retention. 707.9 Section 707.9 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS TRUTH IN SAVINGS § 707.9 Enforcement and record retention. (a) Administrative enforcement. Section 270...

  3. 28 CFR 543.12 - Retention of attorneys.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Retention of attorneys. 543.12 Section... MATTERS Inmate Legal Activities § 543.12 Retention of attorneys. (a) The Warden shall allow an inmate to contact and retain attorneys. With the written consent of the inmate, staff may advise an attorney of...

  4. 16 CFR 453.6 - Retention of documents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Retention of documents. 453.6 Section 453.6 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES FUNERAL INDUSTRY PRACTICES § 453.6 Retention of documents. To prevent the unfair or deceptive acts or practices specified in §§ 453.2 and...

  5. 42 CFR 35.31 - Retention by patients.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Retention by patients. 35.31 Section 35.31 Public... HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.31 Retention by patients. Subject to the rules of the station or hospital, patients may be accorded the privilege of...

  6. Retention Initiatives Used by Professional Bachelor's Athletic Training Program Directors

    ERIC Educational Resources Information Center

    Bowman, Thomas G.; Mazerolle, Stephanie M.; Dodge, Thomas M.

    2016-01-01

    Context: Retaining athletic training students has been identified as problematic by approximately half of athletic training program (ATP) directors. It is unknown what ATP directors do to improve athletic training student retention. Objective: To identify initiatives that ATP directors use to improve the retention rates of athletic training…

  7. 45 CFR 650.8 - Retention of rights by inventor.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Retention of rights by inventor. 650.8 Section 650.8 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PATENTS § 650.8 Retention of rights by inventor. If an awardee elects not to retain rights to an...

  8. 12 CFR 1030.9 - Enforcement and record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 9 2014-01-01 2014-01-01 false Enforcement and record retention. 1030.9...) § 1030.9 Enforcement and record retention. (a) Administrative enforcement. Section 270 of the act (12 U.S.C. 4309) contains the provisions relating to administrative sanctions for failure to comply with...

  9. 48 CFR 1652.204-70 - Contractor records retention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contractor records... of FEHBP Clauses 1652.204-70 Contractor records retention. As prescribed in 1604.705 the following clause will be inserted in all FEHB Program contracts. Contractor Records Retention (JUL...

  10. 48 CFR 2152.215-70 - Contractor records retention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contractor records... PRECONTRACT PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 2152.215-70 Contractor records retention. As prescribed in 2115.071, insert the following clause: Contractor Records Retention (OCT...

  11. 19 CFR 143.37 - Retention of records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Retention of records. 143.37 Section 143.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) SPECIAL ENTRY PROCEDURES Electronic Entry Filing § 143.37 Retention of records....

  12. 19 CFR 181.49 - Retention of records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Retention of records. 181.49 Section 181.49 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... Programs § 181.49 Retention of records. All records required to be kept by the exporter,...

  13. 11 CFR 9039.1 - Retention of books and records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 11 Federal Elections 1 2012-01-01 2012-01-01 false Retention of books and records. 9039.1 Section... PRIMARY MATCHING FUND REVIEW AND INVESTIGATION AUTHORITY § 9039.1 Retention of books and records. The candidate and his or her authorized committee(s) shall keep all books, records and other...

  14. 11 CFR 9039.1 - Retention of books and records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 11 Federal Elections 1 2013-01-01 2012-01-01 true Retention of books and records. 9039.1 Section... PRIMARY MATCHING FUND REVIEW AND INVESTIGATION AUTHORITY § 9039.1 Retention of books and records. The candidate and his or her authorized committee(s) shall keep all books, records and other...

  15. 11 CFR 9039.1 - Retention of books and records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 11 Federal Elections 1 2011-01-01 2011-01-01 false Retention of books and records. 9039.1 Section... PRIMARY MATCHING FUND REVIEW AND INVESTIGATION AUTHORITY § 9039.1 Retention of books and records. The candidate and his or her authorized committee(s) shall keep all books, records and other...

  16. 11 CFR 9039.1 - Retention of books and records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 11 Federal Elections 1 2014-01-01 2014-01-01 false Retention of books and records. 9039.1 Section... PRIMARY MATCHING FUND REVIEW AND INVESTIGATION AUTHORITY § 9039.1 Retention of books and records. The candidate and his or her authorized committee(s) shall keep all books, records and other...

  17. Incorporating carbon saturation concepts and nitrogen retention theory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent advances in soil C saturation concepts have increased our understanding of soil C storage and mineralization without explicit links to N retention and saturation theories. Here, we exploit a soil texture gradient to test hypotheses that link C saturation with soil 15N retention and nitrifica...

  18. Recruitment and Retention of Black Students in Higher Education.

    ERIC Educational Resources Information Center

    Niba, Johnson N., Ed.; Norman, Regina, Ed.

    Six articles on recruitment and retention of black students are presented that cite dropping out as the factor most responsible for significantly impeding minority access to and successful progress in the collegiate experience. Increasingly, retention is becoming the ultimate yardstick for measuring institutional effectiveness, which translates…

  19. Designing Incentives for Marine Corps Cyber Workforce Retention

    DTIC Science & Technology

    2014-12-01

    to explore these challenges. Key fmdings show the importance of tailoring retention policies across three areas: monetary rewards (money and...retention policies across three areas: monetary rewards (money and benefits), non- monetary rewards (duty station preference, geographic stability...aviators. Qualified personnel matter in highly technical fields such as aviation and cyber security (DOD 2014). When bonuses or other types of monetary

  20. 19 CFR 143.37 - Retention of records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Retention of records. 143.37 Section 143.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) SPECIAL ENTRY PROCEDURES Electronic Entry Filing § 143.37 Retention of records....

  1. Retention in Special Education Teachers in Georgia: A Phenomenological Approach

    ERIC Educational Resources Information Center

    Jackson, Arndra N.

    2012-01-01

    The purpose of this qualitative study using a phenomenological approach was to identify and examine factors influencing the retention rate of special education teachers in rural and urban schools in middle Georgia. Provided in this study are factors that are related to retention in special education teachers. Semistructured interviews were used to…

  2. Catholic School Principal Job Satisfaction: Keys to Retention and Recruitment

    ERIC Educational Resources Information Center

    Fraser, Jennifer; Brock, Barbara L.

    2006-01-01

    This article presents a study on principal retention in New South Wales, Australia. Factors in job retention included economic security, role enjoyment, and the opportunity to contribute. Disincentives to the principalship included lack of support from the employing authority, inadequate pay, isolation, growing responsibilities, difficult parents,…

  3. Mentoring: the retention factor in the acute care setting.

    PubMed

    Funderburk, Amy E

    2008-01-01

    The most difficult time to retain staff nurses can be the first year after hire. Because of the high costs of recruitment and orientation, retention of these new employees is essential. Mentoring is a viable retention tool for the new employee and for existing experienced nurses. Mentoring also provides professional growth benefits that appeal to existing employees and increase their job enjoyment and satisfaction.

  4. Mapping a Retention Index across the Student Continuum

    ERIC Educational Resources Information Center

    van der Merwe, C. A.

    2011-01-01

    Student retention is the field of institutional research that has (deservedly) had the most attention. Besides the models proposed by Tinto (1975, 1993), there have been many theoretical and applied papers on many aspects of student retention. These include demographic characteristics, scholastic scores, financial and residential considerations,…

  5. 42 CFR 35.31 - Retention by patients.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Retention by patients. 35.31 Section 35.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.31 Retention by...

  6. Retention of Community College Students: Related Student and Institutional Characteristics

    ERIC Educational Resources Information Center

    Craig, Alfred J.; Ward, Cynthia V. L.

    2008-01-01

    Public community colleges were established to improve access to higher education. However, access for all often results in low student retention and in the loss of effort, time, and money for students and institutions. This institutional specific retention study, which examined student factors, both demographic and academic, and institutional…

  7. Effects of Targeted Sales Messages on Subscription Sales and Retention.

    ERIC Educational Resources Information Center

    Gamst, Glenn; And Others

    1987-01-01

    Investigates the effects of targeted sales messages on newspaper subscription sales and retention by combining two large research projects--a demographic market segmentation scheme, and a readership-lifestyle survey. Proposes that the content of sales messages influences new subscriptions but does not affect retention. (MM)

  8. 42 CFR 35.31 - Retention by patients.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Retention by patients. 35.31 Section 35.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.31 Retention by...

  9. 42 CFR 35.31 - Retention by patients.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Retention by patients. 35.31 Section 35.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.31 Retention by...

  10. 42 CFR 35.31 - Retention by patients.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Retention by patients. 35.31 Section 35.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.31 Retention by...

  11. Negligent Hiring and Retention. School Management Advisor, Issue 27.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh.

    This document examines legal issues in the negligent hiring and retention of North Carolina Department of Public Instruction school employees. There are no statutes that relate specifically to negligent hiring or retention; it is a judicially created area of law. This document centers around employees who cause injury to school children, but the…

  12. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  13. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  14. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  15. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  16. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  17. IDENTIFYING RECRUITMENT AND RETENTION ISSUES FOR THE NATIONAL CHILDREN'S STUDY

    EPA Science Inventory

    Recruitment and Retention Issues for the National Children's Study
    Danelle T Lobdell1, Suzanne Gilboa2, Pauline Mendola1 (1US EPA, NHEERL; 2UNC Chapel Hill)

    A better understanding of the most effective recruitment techniques and retention strategies for longitudinal, co...

  18. 29 CFR 500.270 - Retention of official record.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Retention of official record. 500.270 Section 500.270 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS MIGRANT AND SEASONAL AGRICULTURAL WORKER PROTECTION Administrative Proceedings Record § 500.270 Retention of...

  19. 4 CFR 5.2 - Grade and pay retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... equal or higher than the retained grade; or (4) Elects in writing to have the benefits of this chapter... 4 Accounts 1 2011-01-01 2011-01-01 false Grade and pay retention. 5.2 Section 5.2 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.2 Grade and pay retention. (a) Change...

  20. 4 CFR 5.2 - Grade and pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... equal or higher than the retained grade; or (4) Elects in writing to have the benefits of this chapter... 4 Accounts 1 2010-01-01 2010-01-01 false Grade and pay retention. 5.2 Section 5.2 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.2 Grade and pay retention. (a) Change...