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Sample records for achieve stable performance

  1. An evolutionary method to achieve stable superpixel tracking

    NASA Astrophysics Data System (ADS)

    Xi, Wenxing; Tang, Xinyi

    2014-11-01

    Object tracking is a hot and hard problem in the computer vision study area.We deal with large objects,which are challenged in many aspects,such as the factors of lighting, size, posture, disturbance, occlusion, and so on.The superpixel tracking method has been proposed to deal with this problem. Unlike many other approaches, it is robust in all the mentioned aspects to some extent. It is very flexible to deal with non-rigid objects just like the meanshift of color histogram does,but can be more advanced, since it takes advantage of the segmented local color histogram. Here we first introduce the adaptive superpixel tracking algorithm, which is comprised by two parts, modeling and confidence mapping using the color features of superpixels.We model them by clustering, just like the "bags of words" method does, and build the cluster confidence.The model is adaptive since it just learns from some latest tracked frames, which can accumulate errors and lead to drift easily. So we propose a refined model, which incorporates the kalman filter's ideas to this problem, by integrating the current model and the new model as an evolutionary one, to better adapt to the object variation and disturbance in subsequent frames, thus achieve more stable tracking. The evolutionary model is achieved by reclustering the cluster centers of the two models, to make new cluster centers and new cluster confidences. We allocate different weight to them, if the current model gets more weight, then the evolutionary model will be more stable, otherwise it will be more adaptive. Finally we give some experiment comparisons between the evolutionary model and the adaptive one. For most cases, when the scene of the object is stable, namely there is no big sudden light change or color change, the evolutionary model outperforms the adaptive one. The reason is that the adaptive one easily learns from other objects. But when the scene suffers big sudden change, the evolutionary model can't quickly adapt

  2. Type A Performance Standards and Goal Achievement.

    ERIC Educational Resources Information Center

    Ward, Clay H.

    Achievement striving is a central dimension of the Type A behavior pattern. To investigate the relationship between Type A behavior pattern, personal performance goals, and goal achievement on two general information tests, 126 undergraduates participated in a two-phase study. First, behavior patterns were assessed using the Framingham Type A…

  3. Achieving fast and stable failure detection in WDM Networks

    NASA Astrophysics Data System (ADS)

    Gao, Donghui; Zhou, Zhiyu; Zhang, Hanyi

    2005-02-01

    In dynamic networks, the failure detection time takes a major part of the convergence time, which is an important network performance index. To detect a node or link failure in the network, traditional protocols, like Hello protocol in OSPF or RSVP, exchanges keep-alive messages between neighboring nodes to keep track of the link/node state. But by default settings, it can get a minimum detection time in the measure of dozens of seconds, which can not meet the demands of fast network convergence and failure recovery. When configuring the related parameters to reduce the detection time, there will be notable instability problems. In this paper, we analyzed the problem and designed a new failure detection algorithm to reduce the network overhead of detection signaling. Through our experiment we found it is effective to enhance the stability by implicitly acknowledge other signaling messages as keep-alive messages. We conducted our proposal and the previous approaches on the ASON test-bed. The experimental results show that our algorithm gives better performances than previous schemes in about an order magnitude reduction of both false failure alarms and queuing delay to other messages, especially under light traffic load.

  4. Achievement Goals in a Presentation Task: Performance Expectancy, Achievement Goals, State Anxiety, and Task Performance

    ERIC Educational Resources Information Center

    Tanaka, Ayumi; Takehara, Takuma; Yamauchi, Hirotsugu

    2006-01-01

    The aims of the study were to test the linkages between achievement goals to task performance, as mediated by state anxiety arousal. Performance expectancy was also examined as antecedents of achievement goals. A presentation task in a computer practice class was used as achievement task. Fifty-three undergraduates (37 females and 16 males) were…

  5. Achievement Goals, Learning Strategies and Instrumental Performance

    ERIC Educational Resources Information Center

    Nielsen, Siw Graabraek

    2008-01-01

    The current study is a survey of the achievement goals of music students and the manner in which their strategies and instrumental performance relate to these goals. In the context of advanced instrumental learning, the rationale for the present study was to contribute to the literature on motivation in music students, and thereby, help teachers…

  6. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  7. Achieving high performance on the Intel Paragon

    SciTech Connect

    Greenberg, D.S.; Maccabe, B.; Riesen, R.; Wheat, S.; Womble, D.

    1993-11-01

    When presented with a new supercomputer most users will first ask {open_quotes}How much faster will my applications run?{close_quotes} and then add a fearful {open_quotes}How much effort will it take me to convert to the new machine?{close_quotes} This paper describes some lessons learned at Sandia while asking these questions about the new 1800+ node Intel Paragon. The authors conclude that the operating system is crucial to both achieving high performance and allowing easy conversion from previous parallel implementations to a new machine. Using the Sandia/UNM Operating System (SUNMOS) they were able to port a LU factorization of dense matrices from the nCUBE2 to the Paragon and achieve 92% scaled speed-up on 1024 nodes. Thus on a 44,000 by 44,000 matrix which had required over 10 hours on the previous machine, they completed in less than 1/2 hour at a rate of over 40 GFLOPS. Two keys to achieving such high performance were the small size of SUNMOS (less than 256 kbytes) and the ability to send large messages with very low overhead.

  8. Outcomes of patients with myelodysplastic syndromes who achieve stable disease after treatment with hypomethylating agents.

    PubMed

    Nazha, Aziz; Sekeres, Mikkael A; Garcia-Manero, Guillermo; Barnard, John; Al Ali, Najla H; Roboz, Gail J; Steensma, David P; DeZern, Amy E; Zimmerman, Cassie; Jabbour, Elias J; Zell, Katrina; List, Alan F; Kantarjian, Hagop M; Maciejewski, Jaroslaw P; Komrokji, Rami S

    2016-02-01

    Treatment with hypomethylating agents (HMAs) improves overall survival (OS) in patients who achieve a response of stable disease (SD) or better (complete remission [CR], partial remission [PR], or hematologic improvement [HI]). It is not well established if patients who achieve SD at 4-6 months of therapy should be offered different therapies to optimize their response or continue with the same regimen. Clinical data were obtained from the MDS Clinical Research Consortium database. SD was defined as no evidence of progression and without achievement of any other responses. Of 291 patients treated with AZA or DAC, 55% achieved their best response (BR) at 4-6 months. Among patients with SD at 4-6 months, 29 (20%) achieved a better response at a later treatment time point. Younger patients with lower bone marrow blast percentages, and intermediate risk per IPSS-R were more likely to achieve a better response (CR, PR, or HI) after SD at 4-6 months. Patients with SD who subsequently achieved CR had superior OS compared to patients who remained with SD (28.1 vs. 14.4 months, respectively, p=.04). In conclusion, patients treated with HMAs who achieves CR after a SD status had longer survival with continuous treatment after 6 months. PMID:26777537

  9. Outcomes of patients with myelodysplastic syndromes who achieve stable disease after treatment with hypomethylating agents

    PubMed Central

    Nazha, Aziz; Sekeres, Mikkael A.; Garcia-Manero, Guillermo; Barnard, John; Al Ali, Najla H.; Roboz, Gail J.; Steensma, David P.; DeZern, Amy E.; Zimmerman, Cassie; Jabbour, Elias J.; Zell, Katrina; List, Alan F.; Kantarjian, Hagop M.; Maciejewski, Jaroslaw P.; Komrokji, Rami S.

    2016-01-01

    Treatment with hypomethylating agents (HMAs) improves overall survival (OS) in patients who achieve a response of stable disease (SD) or better (complete remission [CR], partial remission [PR], or hematologic improvement [HI]). It is not well established if patients who achieve SD at 4–6 months of therapy should be offered different therapies to optimize their response or continue with the same regimen. Clinical data were obtained from the MDS Clinical Research Consortium database. SD was defined as no evidence of progression and without achievement of any other responses. Of 291 patients treated with AZA or DAC, 55% achieved their best response (BR) at 4–6 months. Among patients with SD at 4–6 months, 29 (20%) achieved a better response at a later treatment time point. Younger patients with lower bone marrow blast percentages, and intermediate risk per IPSS-R were more likely to achieve a better response (CR, PR, or HI) after SD at 4–6 months. Patients with SD who subsequently achieved CR had superior OS compared to patients who remained with SD (28.1 vs. 14.4 months, respectively, p =.04). In conclusion, patients treated with HMAs who achieves CR after a SD status had longer survival with continuous treatment after 6 months. PMID:26777537

  10. Using the 2 x 2 Framework of Achievement Goals to Predict Achievement Emotions and Academic Performance

    ERIC Educational Resources Information Center

    Putwain, David W.; Sander, Paul; Larkin, Derek

    2013-01-01

    Previous work has established how achievement emotions are related to the trichotomous model of achievement goals, and how they predict academic performance. In our study we examine relations using an additional, mastery-avoidance goal, and whether outcome-focused emotions are predicted by mastery as well as performance goals. Results showed that…

  11. Use a linear model to achieve stable composition control in a naphtha splitter

    SciTech Connect

    Karpe, P.

    1997-01-01

    The following two points using dual composition control in a naphtha splitter are emphasized: while literature provides general guidelines for design of control systems for distillation columns, each column is unique in terms of dynamic and steady state behavior. Multivariable control analytical tools, such as RGA and SVD, coupled with rigorous steady state simulations, can be effectively employed to achieve stable control in columns beset with severe loop interactions, and often in the absence of on-line analyzers, linear models representing the first order approximations of distillation columns can yield significant benefits. Such models are simple to understand, readily acceptable to operators, do not require special expertise to maintain, and therefore, offer high degree of reliability.

  12. Relative performance of a vibratory energy harvester in mono- and bi-stable potentials

    NASA Astrophysics Data System (ADS)

    Masana, Ravindra; Daqaq, Mohammed F.

    2011-11-01

    Motivated by the need for broadband vibratory energy harvesting, many research studies have recently proposed energy harvesters with nonlinear characteristics. Based on the shape of their potential function, such devices are classified as either mono- or bi-stable energy harvesters. This paper aims to investigate the relative performance of these two classes under similar excitations and electric loading conditions. To achieve this goal, an energy harvester consisting of a clamped-clamped piezoelectric beam bi-morph is considered. The shape of the harvester's potential function is altered by applying a static compressive axial load at one end of the beam. This permits operation in the mono-stable (pre-buckling) and bi-stable (post-buckling) configurations. For the purpose of performance comparison, the axial load is used to tune the harvester's oscillation frequencies around the static equilibria such that they have equal values in the mono- and bi-stable configurations. The harvester is subjected to harmonic base excitations of different magnitudes and a slowly varying frequency spanning a wide band around the tuned oscillation frequency. The output voltage measured across a purely resistive load is compared over the frequency range considered. Two cases are discussed; the first compares the performance when the bi-stable harvester has deep potential wells, while the second treats a bi-stable harvester with shallow wells. Both numerical and experimental results demonstrate the essential role that the potential shape plays in conjunction with the base acceleration to determine whether the bi-stable harvester can outperform the mono-stable one and for what range of frequencies. Results also illustrate that, for a bi-stable harvester with shallow potential wells, super-harmonic resonances can activate the inter-well dynamics even for a small base acceleration, thereby producing large voltages in the low frequency range.

  13. Classroom Environment, Achievement Goals and Maths Performance: Gender Differences

    ERIC Educational Resources Information Center

    Gherasim, Loredana Ruxandra; Butnaru, Simona; Mairean, Cornelia

    2013-01-01

    This study investigated how gender shapes the relationships between classroom environment, achievement goals and maths performance. Seventh-grade students ("N"?=?498) from five urban secondary schools filled in achievement goal orientations and classroom environment scales at the beginning of the second semester. Maths performance was assessed as…

  14. A Model of Statistics Performance Based on Achievement Goal Theory.

    ERIC Educational Resources Information Center

    Bandalos, Deborah L.; Finney, Sara J.; Geske, Jenenne A.

    2003-01-01

    Tests a model of statistics performance based on achievement goal theory. Both learning and performance goals affected achievement indirectly through study strategies, self-efficacy, and test anxiety. Implications of these findings for teaching and learning statistics are discussed. (Contains 47 references, 3 tables, 3 figures, and 1 appendix.)…

  15. Extremely Stable Polypyrrole Achieved via Molecular Ordering for Highly Flexible Supercapacitors.

    PubMed

    Huang, Yan; Zhu, Minshen; Pei, Zengxia; Huang, Yang; Geng, Huiyuan; Zhi, Chunyi

    2016-01-27

    The cycling stability of flexible supercapacitors with conducting polymers as electrodes is limited by the structural breakdown arising from repetitive counterion flow during charging/discharging. Supercapacitors made of facilely electropolymerized polypyrrole (e-PPy) have ultrahigh capacitance retentions of more than 97, 91, and 86% after 15000, 50000, and 100000 charging/discharging cycles, respectively, and can sustain more than 230000 charging/discharging cycles with still approximately half of the initial capacitance retained. To the best of our knowledge, such excellent long-term cycling stability was never reported. The fully controllable electropolymerization shows superiority in molecular ordering, favoring uniform stress distribution and charge transfer. Being left at ambient conditions for even 8 months, e-PPy supercapacitors completely retain the good electrochemical performance. The extremely stable supercapacitors with excellent flexibility and scalability hold considerable promise for the commerical application of flexible and wearable electronics. PMID:26741145

  16. Conservation and Achievement Test Performance among Fifth-Graders.

    ERIC Educational Resources Information Center

    Silliphant, Virginia M.; Cox, David L.

    The relationship between conservation and achievement is examined on specific tests and test items on the Stanford Achievement Test Battery used in the elementary years. Specifically, performance on two tests (Word Meaning and Arithmetic Concepts) were analyzed according to subjects level of thinking (concrete or formal) for total score,…

  17. Force production during squats performed with a rotational resistance device under stable versus unstable conditions

    PubMed Central

    Moras, Gerard; Vázquez-Guerrero, Jairo

    2015-01-01

    [Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Forcemean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The forcepeak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in forcemean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar forcemean and forcepeak under stable and unstable conditions. The forcepeak produced is also similar in concentric and eccentric phases. PMID:26696707

  18. Force production during squats performed with a rotational resistance device under stable versus unstable conditions.

    PubMed

    Moras, Gerard; Vázquez-Guerrero, Jairo

    2015-11-01

    [Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Forcemean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The forcepeak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in forcemean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar forcemean and forcepeak under stable and unstable conditions. The forcepeak produced is also similar in concentric and eccentric phases. PMID:26696707

  19. Achieving Deeper Energy Savings in Federal Energy Performance Contracts

    SciTech Connect

    Shonder, John A.; Nasseri, Cyrus

    2015-01-01

    Legislation requires each agency of the US federal government to reduce the aggregate energy use index of its buildings by 30% by 2015, with respect to a 2003 baseline. The declining availability of appropriated funding means that energy performance contracting will be key to achieving this goal. Historically however, energy performance contracts have been able to reduce energy use by only about 20% over baseline. Achieving 30% energy reductions using performance contracting will require new approaches and a specific focus on achieving higher energy savings, both by ESCOs and by agencies. This paper describes some of the ways federal agencies are meeting this challenge, and presents results from the efforts of one agency the US General Services Administration -- to achieve deeper energy savings in conventional energy savings performance contracts.

  20. Achieving Deeper Energy Savings in Federal Energy Performance Contracts

    DOE PAGESBeta

    Shonder, John A.; Nasseri, Cyrus

    2015-01-01

    Legislation requires each agency of the US federal government to reduce the aggregate energy use index of its buildings by 30% by 2015, with respect to a 2003 baseline. The declining availability of appropriated funding means that energy performance contracting will be key to achieving this goal. Historically however, energy performance contracts have been able to reduce energy use by only about 20% over baseline. Achieving 30% energy reductions using performance contracting will require new approaches and a specific focus on achieving higher energy savings, both by ESCOs and by agencies. This paper describes some of the ways federal agenciesmore » are meeting this challenge, and presents results from the efforts of one agency the US General Services Administration -- to achieve deeper energy savings in conventional energy savings performance contracts.« less

  1. Mind the bubbles: achieving stable measurements of maximum hydraulic conductivity through woody plant samples

    PubMed Central

    Espino, Susana; Schenk, H. Jochen

    2011-01-01

    The maximum specific hydraulic conductivity (kmax) of a plant sample is a measure of the ability of a plants’ vascular system to transport water and dissolved nutrients under optimum conditions. Precise measurements of kmax are needed in comparative studies of hydraulic conductivity, as well as for measuring the formation and repair of xylem embolisms. Unstable measurements of kmax are a common problem when measuring woody plant samples and it is commonly observed that kmax declines from initially high values, especially when positive water pressure is used to flush out embolisms. This study was designed to test five hypotheses that could potentially explain declines in kmax under positive pressure: (i) non-steady-state flow; (ii) swelling of pectin hydrogels in inter-vessel pit membranes; (iii) nucleation and coalescence of bubbles at constrictions in the xylem; (iv) physiological wounding responses; and (v) passive wounding responses, such as clogging of the xylem by debris. Prehydrated woody stems from Laurus nobilis (Lauraceae) and Encelia farinosa (Asteraceae) collected from plants grown in the Fullerton Arboretum in Southern California, were used to test these hypotheses using a xylem embolism meter (XYL'EM). Treatments included simultaneous measurements of stem inflow and outflow, enzyme inhibitors, stem-debarking, low water temperatures, different water degassing techniques, and varied concentrations of calcium, potassium, magnesium, and copper salts in aqueous measurement solutions. Stable measurements of kmax were observed at concentrations of calcium, potassium, and magnesium salts high enough to suppress bubble coalescence, as well as with deionized water that was degassed using a membrane contactor under strong vacuum. Bubble formation and coalescence under positive pressure in the xylem therefore appear to be the main cause for declining kmax values. Our findings suggest that degassing of water is essential for achieving stable and precise

  2. Stable same-sex friendships with higher achieving partners promote mathematical reasoning in lower achieving primary school children.

    PubMed

    DeLay, Dawn; Laursen, Brett; Kiuru, Noona; Poikkeus, Anna-Maija; Aunola, Kaisa; Nurmi, Jari-Erik

    2015-11-01

    This study was designed to investigate friend influence over mathematical reasoning in a sample of 374 children in 187 same-sex friend dyads (184 girls in 92 friendships; 190 boys in 95 friendships). Participants completed surveys that measured mathematical reasoning in the 3rd grade (approximately 9 years old) and 1 year later in the 4th grade (approximately 10 years old). Analyses designed for dyadic data (i.e., longitudinal actor-partner interdependence model) indicated that higher achieving friends influenced the mathematical reasoning of lower achieving friends, but not the reverse. Specifically, greater initial levels of mathematical reasoning among higher achieving partners in the 3rd grade predicted greater increases in mathematical reasoning from 3rd grade to 4th grade among lower achieving partners. These effects held after controlling for peer acceptance and rejection, task avoidance, interest in mathematics, maternal support for homework, parental education, length of the friendship, and friendship group norms on mathematical reasoning. PMID:26402901

  3. Raising the Achievement of Low-Performing Students. Policy Brief.

    ERIC Educational Resources Information Center

    Goodwin, Bryan

    This brief synthesizes seven papers commissioned for a series of meetings convened by Mid-Continent Research for Education and Learning to discuss raising the achievement of low-performing students. The purpose of the brief is to identify some causes of the low performance of marginalized students, and then offer research-based solutions for what…

  4. School Performance Indicators, Accountability Ratings, and Student Achievement

    ERIC Educational Resources Information Center

    Jackson, Shirley A.; Lunenburg, Fred C.

    2010-01-01

    Researchers have been challenged to find school-level characteristics that make a difference in student achievement. This study focused on a diverse sample of 24 middle schools to examine differences between schools rated Exemplary, Recognized, Academically Acceptable, and Academically Unacceptable on four performance indicator dimensions:…

  5. Performance Achievement and Analysis of Teaching during Choral Rehearsals.

    ERIC Educational Resources Information Center

    Davis, Anita P.

    1998-01-01

    Evaluates teaching sequences in high-school choral rehearsals to provide insight into the relationship between ensemble achievement and performance preparation. Indicates that teacher pace improvement is unrelated to ensemble maturity, teacher verbalization may not relate to success, and teacher assistance and instructions decrease with student…

  6. The Effect of Contiguity on Informational Achievement and Psychomotor Performance.

    ERIC Educational Resources Information Center

    Hudson, Donald W.

    Using a randomized block design and involving the participation of 73 fifth, sixth, and seventh grade pupils, this study sought to ascertain the relative effects of traditional, varied and integrated contiguity on the achievement of information content and the performance of a psychomotor task. The informational content selected for the study…

  7. Sex Differences in Item Performance on a Standardized Achievement Battery.

    ERIC Educational Resources Information Center

    Green, Donald Ross

    Differential functioning of males and females on achievement test items was studied in a sample of 110,000 students in kindergarten through grade 12. First, item parameters and ability estimates for these parameters were obtained from LOGIST computer program runs for the entire group. Predicted performance for each item for each group was…

  8. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    PubMed Central

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  9. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-10-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

  10. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors.

    PubMed

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W; Chatterjee, Shahana; Erwin, William R; Bardhan, Rizia; Weiss, Sharon M; Pint, Cary L

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  11. Implicit Guidance to Stable Performance in a Rhythmic Perceptual-Motor Skill

    PubMed Central

    Huber, Meghan E.; Sternad, Dagmar

    2015-01-01

    Feedback information about error or reward is regarded essential to aid learners to acquire a perceptual-motor skill. Yet, simple error feedback does not suffice in guiding the learner towards the optimal solutions, when tasks have redundancy where the mapping between execution and performance outcome is unknown. The present study developed and tested a new means of implicitly guiding learners to acquire a perceptual-motor skill, rhythmically bouncing a ball on a racket. Due to its rhythmic nature, this task affords dynamically stable solutions that are resistant to small errors and noise, a strategy that is independent from simply reducing error. Based on the task model implemented in a virtual environment, a state-dependent manipulation was designed that shifted the range of ball-racket contacts that achieved to dynamically stable solutions. In two experiments, subjects practiced with this manipulation that guided them to impact the ball with more negative racket accelerations, the indicator for the strategy with dynamic stability. Subjects who practiced under normal conditions took longer time to acquire this skill, although error measures were identical between the control and experimental groups. Unlike in many other haptic guidance or adaptation studies, the experimental groups not only learned but also maintained the stable solution after the manipulation was removed. These results are a first demonstration that more subtle ways to guide the learner to better performance are needed to assist performance improvements, especially in tasks with redundancy, where error feedback may not be sufficient. PMID:25821180

  12. Implicit guidance to stable performance in a rhythmic perceptual-motor skill.

    PubMed

    Huber, Meghan E; Sternad, Dagmar

    2015-06-01

    Feedback about error or reward is regarded essential for aiding learners to acquire a perceptual-motor skill. Yet, when a task has redundancy and the mapping between execution and performance outcome is unknown, simple error feedback does not suffice in guiding the learner toward the optimal solutions. The present study developed and tested a new means of implicitly guiding learners to acquire a perceptual-motor skill, rhythmically bouncing a ball on a racket. Due to its rhythmic nature, this task affords dynamically stable solutions that are robust to small errors and noise, a strategy that is independent from actively correcting error. Based on the task model implemented in a virtual environment, a time-shift manipulation was designed to shift the range of ball-racket contacts that achieved dynamically stable solutions. In two experiments, subjects practiced with this manipulation that guided them to impact the ball with more negative racket accelerations, the indicator for the strategy with dynamic stability. Subjects who practiced under normal conditions took longer time to acquire this strategy, although error measures were identical between the control and experimental groups. Unlike in many other haptic guidance or adaptation studies, the experimental groups not only learned, but also maintained the stable solution after the manipulation was removed. These results are a first demonstration that more subtle ways to guide the learner to better performance are needed especially in tasks with redundancy, where error feedback may not be sufficient. PMID:25821180

  13. Prehension synergies: trial-to-trial variability and hierarchical organization of stable performance

    PubMed Central

    Shim, Jae K.; Latash, Mark L.

    2010-01-01

    We studied multi-digit synergies as relations among digit forces and points of their application across multiple repetitions of a static prehensile task. The task required holding a grasped object (14.9 N) against different external torques. Subjects (n=6) performed 25 trials for each torque condition: −1.0, −0.5, 0, +0.5 and +1.0 Nm. In spite of the variability of individual forces and points of their application, stable performance was achieved. Individual performance variables were organized into two subsets. Variables within each subset highly correlated with each other (the coefficients of correlation were close to ±1.0) while there was no correlation among variables from different subsets. The two subsets were associated with two components of the prehension task: grasp control (preventing an object from slipping out of the hand) and torque control (maintaining a desired object orientation). PMID:12898101

  14. Long term, stable brain machine interface performance using local field potentials and multiunit spikes

    NASA Astrophysics Data System (ADS)

    Flint, Robert D.; Wright, Zachary A.; Scheid, Michael R.; Slutzky, Marc W.

    2013-10-01

    Objective. Brain machine interfaces (BMIs) have the potential to restore movement to people with paralysis. However, a clinically-viable BMI must enable consistently accurate control over time spans ranging from years to decades, which has not yet been demonstrated. Most BMIs that use single-unit spikes as inputs will experience degraded performance over time without frequent decoder re-training. Two other signals, local field potentials (LFPs) and multi-unit spikes (MSPs), may offer greater reliability over long periods and better performance stability than single-unit spikes. Here, we demonstrate that LFPs can be used in a biomimetic BMI to control a computer cursor. Approach. We implanted two rhesus macaques with intracortical microelectrodes in primary motor cortex. We recorded LFP and MSP signals from the monkeys while they performed a continuous reaching task, moving a cursor to randomly-placed targets on a computer screen. We then used the LFP and MSP signals to construct biomimetic decoders for control of the cursor. Main results. Both monkeys achieved high-performance, continuous control that remained stable or improved over nearly 12 months using an LFP decoder that was not retrained or adapted. In parallel, the monkeys used MSPs to control a BMI without retraining or adaptation and had similar or better performance, and that predominantly remained stable over more than six months. In contrast to their stable online control, both LFP and MSP signals showed substantial variability when used offline to predict hand movements. Significance. Our results suggest that the monkeys were able to stabilize the relationship between neural activity and cursor movement during online BMI control, despite variability in the relationship between neural activity and hand movements.

  15. Carboxylate-based molecular magnet: One path toward achieving stable quantum correlations at room temperature

    NASA Astrophysics Data System (ADS)

    Cruz, C.; Soares-Pinto, D. O.; Brandão, P.; dos Santos, A. M.; Reis, M. S.

    2016-02-01

    The control of quantum correlations in solid-state systems by means of material engineering is a broad avenue to be explored, since it makes possible steps toward the limits of quantum mechanics and the design of novel materials with applications on emerging quantum technologies. In this context, this letter explores the potential of molecular magnets to be prototypes of materials for quantum information technology. More precisely, we engineered a material and from its geometric quantum discord we found significant quantum correlations up to 9540 K (even without entanglement); and, in addition, a pure singlet state occupied up to around 80 K (above liquid nitrogen temperature). These results could only be achieved due to the carboxylate group promoting a metal-to-metal huge magnetic interaction.

  16. Science Achievement for All: Improving Science Performance and Closing Achievement Gaps

    ERIC Educational Resources Information Center

    Jackson, Julie K.; Ash, Gwynne

    2012-01-01

    This article addresses the serious and growing need to improve science instruction and science achievement for all students. We will describe the results of a 3-year study that transformed science instruction and student achievement at two high-poverty ethnically diverse public elementary schools in Texas. The school-wide intervention included…

  17. Achieving fast timing performance with multiplexed SiPMs.

    PubMed

    Bieniosek, M F; Cates, J W; Levin, C S

    2016-04-01

    Using time of flight (ToF) measurements for positron emission tomography (PET) is an attractive avenue for increasing the signal to noise (SNR) ratio of PET images. However, achieving excellent time resolution required for high SNR gain using silicon photomultipliers (SiPM) requires many resource heavy high bandwidth readout channels. A method of multiplexing many SiPM signals into a single electronic channel would greatly simplify ToF PET systems. However, multiplexing SiPMs degrades time resolution because of added dark counts and signal shaping. In this work the relative contribution of dark counts and signal shaping to timing degradation is simulated and a baseline correction technique to mitigate the effect of multiplexing on the time resolution of analog SiPMs is simulated and experimentally verified. A charge sharing network for multiplexing is proposed and tested. Results show a full width at half maximum (FWHM) coincidence time resolution of [Formula: see text] ps for a single 3 mm  ×  3 mm  ×  20 mm LYSO scintillation crystals coupled to an array of sixteen 3 mm  ×  3 mm SiPMs that are multiplexed to a single timing channel (in addition to 4 position channels). A [Formula: see text] array of 3 mm  ×  3 mm  ×  20 mm LFS crystals showed an average FWHM coincidence time resolution of [Formula: see text] ps using the same timing scheme. All experiments were performed at room temperature with no thermal regulation. These results show that excellent time resolution for ToF can be achieved with a highly multiplexed analog SiPM readout. PMID:26987898

  18. Achieving fast timing performance with multiplexed SiPMs

    NASA Astrophysics Data System (ADS)

    Bieniosek, M. F.; Cates, J. W.; Levin, C. S.

    2016-04-01

    Using time of flight (ToF) measurements for positron emission tomography (PET) is an attractive avenue for increasing the signal to noise (SNR) ratio of PET images. However, achieving excellent time resolution required for high SNR gain using silicon photomultipliers (SiPM) requires many resource heavy high bandwidth readout channels. A method of multiplexing many SiPM signals into a single electronic channel would greatly simplify ToF PET systems. However, multiplexing SiPMs degrades time resolution because of added dark counts and signal shaping. In this work the relative contribution of dark counts and signal shaping to timing degradation is simulated and a baseline correction technique to mitigate the effect of multiplexing on the time resolution of analog SiPMs is simulated and experimentally verified. A charge sharing network for multiplexing is proposed and tested. Results show a full width at half maximum (FWHM) coincidence time resolution of 232+/- 2 ps for a single 3 mm  ×  3 mm  ×  20 mm LYSO scintillation crystals coupled to an array of sixteen 3 mm  ×  3 mm SiPMs that are multiplexed to a single timing channel (in addition to 4 position channels). A 4× 4 array of 3 mm  ×  3 mm  ×  20 mm LFS crystals showed an average FWHM coincidence time resolution of 278+/- 7 ps using the same timing scheme. All experiments were performed at room temperature with no thermal regulation. These results show that excellent time resolution for ToF can be achieved with a highly multiplexed analog SiPM readout.

  19. Science Achievement for All: Improving Science Performance and Closing Achievement Gaps

    NASA Astrophysics Data System (ADS)

    Jackson, Julie K.; Ash, Gwynne

    2012-11-01

    This article addresses the serious and growing need to improve science instruction and science achievement for all students. We will describe the results of a 3-year study that transformed science instruction and student achievement at two high-poverty ethnically diverse public elementary schools in Texas. The school-wide intervention included purposeful planning, inquiry science instruction, and contextually rich academic science vocabulary development. In combination, these instructional practices rapidly improved student-science learning outcomes and narrowed achievement gaps across diverse student populations.

  20. The role of shaping in achieving high performance in DIII-D

    SciTech Connect

    Lazarus, E.A.; Hyatt, A.W.; Osborne, T.H.

    1994-10-01

    Experiments to study the effect of plasma shape on performance show that the high performance levels characteristic of VH-mode plasmas are only obtained for high triangularity ({delta}). A characteristic difference in central heating efficiency is observed when high and low {delta} plasmas are compared. The authors find this difference to correlate well with the attainment of Mercier stability. The core plasma for the high {delta} cases achieves Mercier stability when q{sub 0} rises above a critical value which depends on {delta}, providing direct access to the second-stable regime. Other attributes of the VH-mode commence after a delay. The rise in q{sub 0} is attributable to the radial gradients in the neutral beam and bootstrap current sources. Simulation indicates that such plasmas would persist for many seconds if the rise in density could be controlled, maintaining a centrally peaked neutral beam deposition profile.

  1. Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation

    PubMed Central

    Wang, Dongbo; Wang, Qilin; Laloo, Andrew; Xu, Yifeng; Bond, Philip L.; Yuan, Zhiguo

    2016-01-01

    Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4+ to NO3−. Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5–3.0 to 0.3–0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater. PMID:27151247

  2. Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation

    NASA Astrophysics Data System (ADS)

    Wang, Dongbo; Wang, Qilin; Laloo, Andrew; Xu, Yifeng; Bond, Philip L.; Yuan, Zhiguo

    2016-05-01

    Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4+ to NO3‑. Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5–3.0 to 0.3–0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater.

  3. Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation.

    PubMed

    Wang, Dongbo; Wang, Qilin; Laloo, Andrew; Xu, Yifeng; Bond, Philip L; Yuan, Zhiguo

    2016-01-01

    Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4(+) to NO3(-). Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5-3.0 to 0.3-0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater. PMID:27151247

  4. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads

    PubMed Central

    Vázquez-Guerrero, Jairo; Moras, Gerard

    2016-01-01

    The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010) and peak force output differed between all loads for each condition (P < 0.045). Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001). There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries. PMID:27111766

  5. Partnering through Training and Practice to Achieve Performance Improvement

    ERIC Educational Resources Information Center

    Lyons, Paul R.

    2010-01-01

    This article presents a partnership effort among managers, trainers, and employees to spring to life performance improvement using the performance templates (P-T) approach. P-T represents a process model as well as a method of training leading to performance improvement. Not only does it add to our repertoire of training and performance management…

  6. Student Achievement and Education System Performance in a Developing Country

    ERIC Educational Resources Information Center

    Marshall, Jeffery H.; Chinna, Ung; Hok, Ung Ngo; Tinon, Souer; Veasna, Meung; Nissay, Put

    2012-01-01

    The global spread of national assessment testing activities, and the growing pressure to move beyond basic measures of participation in educational monitoring, means that student achievement measures are likely to become increasingly relevant indicators of systemic progress in the developing world. Using data from the CESSP project in Cambodia,…

  7. Concurrently adjusting interrelated control parameters to achieve optimal engine performance

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2015-12-01

    Methods and systems for real-time engine control optimization are provided. A value of an engine performance variable is determined, a value of a first operating condition and a value of a second operating condition of a vehicle engine are detected, and initial values for a first engine control parameter and a second engine control parameter are determined based on the detected first operating condition and the detected second operating condition. The initial values for the first engine control parameter and the second engine control parameter are adjusted based on the determined value of the engine performance variable to cause the engine performance variable to approach a target engine performance variable. In order to cause the engine performance variable to approach the target engine performance variable, adjusting the initial value for the first engine control parameter necessitates a corresponding adjustment of the initial value for the second engine control parameter.

  8. Achieving intelligent performance in autonomous on-road driving

    NASA Astrophysics Data System (ADS)

    Schlenoff, Craig I.; Evans, John M.; Barbera, Anthony J.; Albus, James S.; Messina, Elena R.; Balakirsky, Stephen B.

    2004-12-01

    This paper describes NIST"s efforts in evaluating what it will take to achieve autonomous human-level driving skills in terms of time and funding. NIST has approached this problem from several perspectives: considering the current state-of-the-art in autonomous navigation and extrapolating from there, decomposing the tasks identified by the Department of Transportation for on-road driving and comparing that with accomplishments to date, analyzing computing power requirements by comparison with the human brain, and conducting a Delphi Forecast using the expert researchers in the field of autonomous driving. A detailed description of each of these approaches is provided along with the major finding from each approach and an overall picture of what it will take to achieve human level driving skills in autonomous vehicles.

  9. Some methods for achieving more efficient performance of fuel assemblies

    NASA Astrophysics Data System (ADS)

    Boltenko, E. A.

    2014-07-01

    More efficient operation of reactor plant fuel assemblies can be achieved through the use of new technical solutions aimed at obtaining more uniform distribution of coolant over the fuel assembly section, more intense heat removal on convex heat-transfer surfaces, and higher values of departure from nucleate boiling ratio (DNBR). Technical solutions using which it is possible to obtain more intense heat removal on convex heat-transfer surfaces and higher DNBR values in reactor plant fuel assemblies are considered. An alternative heat removal arrangement is described using which it is possible to obtain a significantly higher power density in a reactor plant and essentially lower maximal fuel rod temperature.

  10. Orchestrating ACO success: how top performers achieve shared savings.

    PubMed

    Harris, John M; Elizondo, Idette; Brown, Amanda M

    2016-03-01

    Leaders of the top-performing accountable care organizations in the Medicare Shared Savings Program attribute the success of their organizations in large part to seven strategies: Seek action-oriented leadership. Transform primary care physician practices. Keep patients out of the emergency department. Ensure all transitions are smooth. Make effective use of available data. Share information on physician performance. Keep patients engaged. PMID:27183758

  11. [Influence of a turkey stable with a veranda on performance, behaviour and health of male turkeys].

    PubMed

    Berk, J; Wartemann, S

    2006-03-01

    Throughout 4 fattening periods (summer and winter) the influence of a veranda (roofed outside run) on the performance, behaviour and health of tom turkeys was investigated in a pilot study. A second conventional naturally ventilated stable without a veranda was also included in the investigations for special aspects. The aim of this study was to investigate this first turkey stable with a veranda and to give first recommendation for the practical use. The use of the veranda and the differences in behaviour between inside the stable with a veranda and inside the veranda as well as inside both stables were analysed. From 100 turkeys in each period we examined feather condition, walking ability and leg posture in the 9th, 13th and 17th week of age in both stables. In addition, body weight, food consumption and mortality were recorded. The results of this pilot study indicate that the tom turkeys of the line BUT Big 6 used the veranda without negative effects on health and performance parameters. There was some indication for an improved health of animals or a reduced mortality in the stable with veranda. The decrease of walking ability and normal leg posture with increasing age and body weight in both stables suggests that the genetic influence seems to have a higher influence than the enrichment of environment in this study using the fast growing line BUT Big 6. On the other hand, in this pilot study only one stable with a veranda and another commercial stable without a veranda at a different location were included. For this reason the results should be interpreted carefully with respect to possible effects in the management between the two farms. PMID:16669193

  12. Student Achievement Data Systems in High and Low Performing Schools

    ERIC Educational Resources Information Center

    Stachowiak, Jeannie E.

    2013-01-01

    The purpose of this study was to determine if there was a difference in how high and low performing elementary school districts use and analyze data to differentiate instruction, make changes to district/grade level curriculum, determine professional development needs, determine teacher effectiveness, and determine the use of school district…

  13. Teacher Performance and Pupil Achievement on Teacher-Made Tests.

    ERIC Educational Resources Information Center

    Ellett, Chad D.; And Others

    This study investigated the predictive validity of the Teacher Performance Assessment Instruments (TPAI) using pupil gains on teacher-made tests (TMT) as a criterion. The TPAI and the TMT's were administered to 56 elementary and secondary classrooms in Georgia. Results supported the validity of the TPAI with a large number of correlations ranging…

  14. Achieving High Performance with FPGA-Based Computing

    PubMed Central

    Herbordt, Martin C.; VanCourt, Tom; Gu, Yongfeng; Sukhwani, Bharat; Conti, Al; Model, Josh; DiSabello, Doug

    2011-01-01

    Numerous application areas, including bioinformatics and computational biology, demand increasing amounts of processing capability. In many cases, the computation cores and data types are suited to field-programmable gate arrays. The challenge is identifying the design techniques that can extract high performance potential from the FPGA fabric. PMID:21603088

  15. Achieving Transformational Materials Performance in a New Era of Science

    ScienceCinema

    John Sarrao

    2010-01-08

    The inability of current materials to meet performance requirements is a key stumbling block for addressing grand challenges in energy and national security. Fortunately, materials research is on the brink of a new era - a transition from observation and validation of materials properties to prediction and control of materials performance. In this talk, I describe the nature of the current challenge, the prospects for success, and a specific facility concept, MaRIE, that will provide the needed capabilities to meet these challenges, especially for materials in extreme environments. MaRIE, for Matter-Radiation Interactions in Extremes, is Los Alamos' concept to realize this vision of 21st century materials research. This vision will be realized through enhancements to the current LANSCE accelerator, development of a fourth-generation x-ray light source co-located with the proton accelerator, and a comprehensive synthesis and characterization facility focused on controlling complex materials and the defect/structure link to materials performance.

  16. 39 CFR 3055.1 - Annual reporting of service performance achievements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Annual reporting of service performance achievements. 3055.1 Section 3055.1 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements § 3055.1 Annual reporting of service performance...

  17. Achieving high sustained performance in an unstructured mesh CFD application

    SciTech Connect

    Keyes, D E; Anderson, W K; Gropp, W D; Kaushik, D K; Smith, B F

    1999-12-10

    This paper highlights a three-year project by an interdisciplinary team on a legacy F77 computational fluid dynamics code, with the aim of demonstrating that implicit unstructured grid simulations can execute at rates not far from those of explicit structured grid codes, provided attention is paid to data motion complexity and the reuse of data positioned at the levels of the memory hierarchy closest to the processor, in addition to traditional operation count complexity. The demonstration code is from NASA and the enabling parallel hardware and (freely available) software toolkit are from DOE, but the resulting methodology should be broadly applicable, and the hardware limitations exposed should allow programmers and vendors of parallel platforms to focus with greater encouragement on sparse codes with indirect addressing. This snapshot of ongoing work shows a performance of 15 microseconds per degree of freedom to steady-state convergence of Euler flow on a mesh with 2.8 million vertices using 3072 dual-processor nodes of ASCI Red, corresponding to a sustained floating-point rate of 0.227 Tflop/s.

  18. 18-Months operation of Lunar-based Ultraviolet Telescope: a highly stable photometric performance

    NASA Astrophysics Data System (ADS)

    Wang, J.; Meng, X. M.; Han, X. H.; Cai, H. B.; Cao, L.; Deng, J. S.; Qiu, Y. L.; Wang, S.; Wei, J. Y.; Hu, J. Y.

    2015-11-01

    We here report the photometric performance of Lunar-based Ultraviolet telescope (LUT), the first robotic telescope working on the Moon, for its 18-months operation. In total, 17 IUE standards have been observed in 51 runs until June 2015, which returns a highly stable photometric performance during the past 18 months (i.e., no evolution of photometric performance with time). The magnitude zero point is determined to be 17.53±0.05 {mag}, which is not only highly consistent with the results based on its first 6-months operation, but also independent on the spectral type of the standard from which the magnitude zero point is determined. The implications of this stable performance is discussed, and is useful for next generation lunar-based astronomical observations.

  19. 39 CFR 3055.30 - Periodic reporting of service performance achievements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Periodic reporting of service performance achievements. 3055.30 Section 3055.30 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service Performance Achievements §...

  20. 39 CFR 3055.2 - Contents of the annual report of service performance achievements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Contents of the annual report of service performance achievements. 3055.2 Section 3055.2 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  1. 39 CFR 3055.30 - Periodic reporting of service performance achievements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Periodic reporting of service performance achievements. 3055.30 Section 3055.30 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service Performance Achievements §...

  2. 39 CFR 3055.1 - Annual reporting of service performance achievements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Annual reporting of service performance achievements. 3055.1 Section 3055.1 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  3. 39 CFR 3055.30 - Periodic reporting of service performance achievements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Periodic reporting of service performance achievements. 3055.30 Section 3055.30 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service Performance Achievements §...

  4. 39 CFR 3055.30 - Periodic reporting of service performance achievements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Periodic reporting of service performance achievements. 3055.30 Section 3055.30 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service Performance Achievements §...

  5. 39 CFR 3055.2 - Contents of the annual report of service performance achievements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Contents of the annual report of service performance achievements. 3055.2 Section 3055.2 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  6. 39 CFR 3055.1 - Annual reporting of service performance achievements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Annual reporting of service performance achievements. 3055.1 Section 3055.1 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  7. 39 CFR 3055.1 - Annual reporting of service performance achievements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Annual reporting of service performance achievements. 3055.1 Section 3055.1 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  8. 39 CFR 3055.2 - Contents of the annual report of service performance achievements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Contents of the annual report of service performance achievements. 3055.2 Section 3055.2 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements § 3055.2 Contents of the annual report...

  9. 39 CFR 3055.2 - Contents of the annual report of service performance achievements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Contents of the annual report of service performance achievements. 3055.2 Section 3055.2 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements §...

  10. Boredom in Achievement Settings: Exploring Control-Value Antecedents and Performance Outcomes of a Neglected Emotion

    ERIC Educational Resources Information Center

    Pekrun, Reinhard; Goetz, Thomas; Daniels, Lia M.; Stupnisky, Robert H.; Perry, Raymond P.

    2010-01-01

    The linkages of achievement-related boredom with students' appraisals and performance outcomes were examined in a series of 5 exploratory, cross-sectional, and predictive investigations. Studies 1 and 2 assessed students' boredom in a single achievement episode (i.e., state achievement boredom); Studies 3, 4, and 5 focused on their habitual…

  11. Relations among Motivation, Performance Achievement, and Music Experience Variables in Secondary Instrumental Music Students

    ERIC Educational Resources Information Center

    Schmidt, Charles P.

    2005-01-01

    The purpose of this study was to (1) reexamine academic achievement motivation orientations within the context of instrumental music, and (2) examine relations among achievement motivation orientations, self-concept in instrumental music, and attitude to band in relation to teachers' ratings of performance achievement and effort, and students'…

  12. Performance Trajectories and Performance Gaps as Achievement Effect-Size Benchmarks for Educational Interventions

    ERIC Educational Resources Information Center

    Bloom, Howard S.; Hill, Carolyn J.; Black, Alison Rebeck; Lipsey, Mark W.

    2008-01-01

    Two complementary approaches to developing empirical benchmarks for achievement effect sizes in educational interventions are explored. The first approach characterizes the natural developmental progress in achievement made by students from one year to the next as effect sizes. Data for seven nationally standardized achievement tests show large…

  13. Performance as a Function of Resultant Achievement Motivation (Perceived Ability) and Perceived Difficulty

    ERIC Educational Resources Information Center

    Kukla, Andy

    1974-01-01

    Data confirmed Kukla's attributional theory of performance. When a task is perceived to be difficult, high resultant achievers perform better than low resultant achievers, whereas the low motive group proves to be superior to the high group when the task is perceived as easy. (Author/RK)

  14. A Comparison of Low Performing Students' Achievements in Factoring Cubic Polynomials Using Three Different Strategies

    ERIC Educational Resources Information Center

    Ogbonnaya, Ugorji I.; Mogari, David L.; Machisi, Eric

    2013-01-01

    In this study, repeated measures design was employed to compare low performing students' achievements in factoring cubic polynomials using three strategies. Twenty-five low-performing Grade 12 students from a secondary school in Limpopo province took part in the study. Data was collected using achievement test and was analysed using repeated…

  15. A Commentary on "Differentiating Low Performance of the Gifted Learner: Achieving, Underachieving, and Selective Consuming Students"

    ERIC Educational Resources Information Center

    Flint, Lori J.; Ritchotte, Jennifer A.

    2012-01-01

    This article presents the authors' critique on "Differentiating Low Performance of the Gifted Learner: Achieving, Underachieving, and Selective Consuming Students" (Figg, Low, McCormick, & Rogers 2012). The authors of "Differentiating Low Performance of the Gifted Learner: Achieving, Underachieving, and Selective Consuming Students" endeavored to…

  16. Predicting Examination Performance Using an Expanded Integrated Hierarchical Model of Test Emotions and Achievement Goals

    ERIC Educational Resources Information Center

    Putwain, Dave; Deveney, Carolyn

    2009-01-01

    The aim of this study was to examine an expanded integrative hierarchical model of test emotions and achievement goal orientations in predicting the examination performance of undergraduate students. Achievement goals were theorised as mediating the relationship between test emotions and performance. 120 undergraduate students completed…

  17. Performance of Children with Autism on Selected Measures of Reading Achievement and Cognitive-Linguistic Ability

    ERIC Educational Resources Information Center

    Turner, Vicky

    2010-01-01

    This study examined the performance of children with autism on selected measures of reading achievement and cognitive-linguistic ability. How children with autism performed on three reading achievement measures, Letter-Word Identification, Passage Comprehension, and Oral Reading Fluency, and two cognitive-linguistic measures, Rapid Letter Naming…

  18. Utopia for Music Performance Graduates. Is It Achievable, and How Should It Be Defined?

    ERIC Educational Resources Information Center

    Bennett, Dawn

    2007-01-01

    For the majority of undergraduate classical music performance students, "musotopia" is a place where performance ambitions are realised with an international performance career. However, given that so few musicians achieve this ambition, should this ideal be redefined? This paper investigates instrumental musicians' careers by exploring…

  19. Do Performance Goals Promote Learning? A Pattern Analysis of Singapore Students' Achievement Goals

    ERIC Educational Resources Information Center

    Luo, Wenshu; Paris, Scott G.; Hogan, David; Luo, Zhiqiang

    2011-01-01

    This study investigated how achievement goals are combined to affect students' learning. We used a multiple goals perspective, based on mastery (i.e., mastery approach) and performance (including both approach and avoidance components) goals, to examine the achievement goal patterns of 1697 Singapore Secondary 3 students in their math study. Four…

  20. Relationship of Achievement Test Scores and State Board Performance in a Diploma Nursing Program.

    ERIC Educational Resources Information Center

    Washburn, Gail

    The relationship between the National League for Nursing (NLN) achievement test scores and performance on the State Board Test Pool Examination (SBTPE) was studied with 166 graduates of a diploma degree school of nursing between 1976 and 1978. It was found that NLN achievement test scores had a highly significant correlation with SBTPE results.…

  1. Positive Biases in Self-Assessment of Mathematics Competence, Achievement Goals, and Mathematics Performance

    ERIC Educational Resources Information Center

    Dupeyrat, Caroline; Escribe, Christian; Huet, Nathalie; Regner, Isabelle

    2011-01-01

    The study examined how biases in self-evaluations of math competence relate to achievement goals and progress in math achievement. It was expected that performance goals would be related to overestimation and mastery goals to accurate self-assessments. A sample of French high-school students completed a questionnaire measuring their math…

  2. A methodology to assess performance of human-robotic systems in achievement of collective tasks

    NASA Technical Reports Server (NTRS)

    Howard, Ayanna M.

    2005-01-01

    In this paper, we present a methodology to assess system performance of human-robotic systems in achievement of collective tasks such as habitat construction, geological sampling, and space exploration.

  3. Neuropsychological and Academic Achievement Correlates of Abnormal WISC-R Verbal-Performance Discrepancies.

    ERIC Educational Resources Information Center

    Lueger, Robert J.; And Others

    1985-01-01

    Examined neuropsychological and academic achievement correlates of statistically abnormal verbal-performance discrepancies on the Wechsler Intelligence Scale for Children (Revised). Results indicated that abnormal discrepancies reflect specific aphasia deficits rather than generalized neuropsychological dysfunction and that academic achievement…

  4. Personality Stability Is Associated With Better Cognitive Performance in Adulthood: Are the Stable More Able?

    PubMed Central

    Lachman, Margie E.

    2012-01-01

    Objectives. Although personality is relatively stable over time, there are individual differences in the patterns and magnitude of change. There is some evidence that personality change in adulthood is related to physical health and longevity. The present study expanded this work to consider whether personality stability or change would be associated with better cognitive functioning, especially in later adulthood. Method. A total of 4,974 individuals participated in two waves of The Midlife in the United States Study (MIDUS) in 1994–1995 and 2004–2005. Participants completed the MIDUS personality inventory at both times and the Brief Test of Adult Cognition by Telephone cognitive battery at Time 2. Results. Multiple regression and analysis of covariance analyses showed that, consistent with predictions, individuals remaining stable in openness to experience and neuroticism had faster reaction times and better inductive reasoning than those who changed. Among older adults, those who remained stable or decreased in neuroticism had significantly faster reaction times than those who increased. Conclusions. As predicted, personality stability on some traits was associated with more adaptive cognitive performance on reasoning and reaction time. Personality is discussed as a possible resource for protecting against or minimizing age-related declines in cognition. PMID:22357641

  5. Regulating Debilitating Emotions in the Context of Performance: Achievement Goal Orientations, Achievement-Elicited Emotions, and Socialization Contexts

    ERIC Educational Resources Information Center

    Tyson, Diana F.; Linnenbrink-Garcia, Lisa; Hill, Nancy E.

    2009-01-01

    A theoretical framework that incorporates emotional responses and emotion regulation into achievement goal theory is proposed as an alternative view to understanding the inconsistent pattern of findings linking achievement goal orientations to academic outcomes. In this critical review and synthesis, the relation of achievement goal orientations…

  6. A Meta-Analysis of Self-Reported Achievement Goals and Nonself-Report Performance across Three Achievement Domains (Work, Sports, and Education)

    PubMed Central

    Van Yperen, Nico W.; Blaga, Monica; Postmes, Tom

    2014-01-01

    During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual’s drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports) are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not) generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG) measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that – overall – approach goals (either mastery or performance) were associated positively with performance attainment, whereas avoidance goals (either mastery or performance) were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of

  7. Prediction of intrinsic motivation and sports performance using 2 x 2 achievement goal framework.

    PubMed

    Li, Chiung-Huang; Chi, Likang; Yeh, Suh-Ruu; Guo, Kwei-Bin; Ou, Cheng-Tsung; Kao, Chun-Chieh

    2011-04-01

    The purpose of this study was to examine the influence of 2 x 2 achievement goals on intrinsic motivation and performance in handball. Participants were 164 high school athletes. All completed the 2 x 2 Achievement Goals Questionnaire for Sport and the Intrinsic Motivation subscale of the Sport Motivation Scale; the coach for each team rated his athletes' overall sports performance. Using simultaneous-regression analyses, mastery-approach goals positively predicted both intrinsic motivation and performance in sports, whereas performance-avoidance goals negatively predicted sports performance. These results suggest that athletes who pursue task mastery and improvement of their competence perform well and enjoy their participation. In contrast, those who focus on avoiding normative incompetence perform poorly. PMID:21675576

  8. The Effects of the Classroom Performance System on Student Participation, Attendance, and Achievement

    ERIC Educational Resources Information Center

    Termos, Mohamad Hani

    2013-01-01

    The Classroom Performance System (CPS) is an instructional technology that increases student performance and promotes active learning. This study assessed the effect of the CPS on student participation, attendance, and achievement in multicultural college-level anatomy and physiology classes, where students' first spoken language is not…

  9. Performance Assessment: Looking at the "Real" Achievement of Middle Level Students.

    ERIC Educational Resources Information Center

    Aseltine, James M.

    1993-01-01

    Performance assessment may be the best vehicle for validating student achievement. Performance assessment, in theory and practice, is compatible with middle-school philosophy, stated mission, organizational structure, and instructional models. The challenge is to reexamine program outcomes and decide what middle-level students should know and be…

  10. Universal Factors of Student Achievement in High-Performing Eastern and Western Countries

    ERIC Educational Resources Information Center

    Lee, Jihyun

    2014-01-01

    This study investigates whether a common set of student attitudes and behavioral tendencies can account for academic achievement across different, especially high-performing, countries via analysis of the PISA 2009 international data set. The 13 countries examined are 5 of the top-performing Eastern countries/systems, namely Shanghai China, South…

  11. 39 CFR 3055.31 - Contents of the Quarterly Report of service performance achievements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Contents of the Quarterly Report of service performance achievements. 3055.31 Section 3055.31 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service...

  12. 39 CFR 3055.31 - Contents of the Quarterly Report of service performance achievements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Contents of the Quarterly Report of service performance achievements. 3055.31 Section 3055.31 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service...

  13. 39 CFR 3055.31 - Contents of the Quarterly Report of service performance achievements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Contents of the Quarterly Report of service performance achievements. 3055.31 Section 3055.31 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service...

  14. 39 CFR 3055.31 - Contents of the Quarterly Report of service performance achievements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Contents of the Quarterly Report of service performance achievements. 3055.31 Section 3055.31 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Periodic Reporting of Service...

  15. Boasts are a boost: achievement prime self-reactivity predicts subsequent academic performance.

    PubMed

    Gramzow, Richard H; Johnson, Camille S; Willard, Greg

    2014-03-01

    The present research tests the hypothesis that self-reactivity following an achievement prime reflects the strength of achievement goals and is a predictor of future goal-relevant performance. In Studies 1-3, undergraduates reported their grade-point averages (GPAs) following either an achievement goal prime or a control prime. Academic exaggeration (higher self-reported than official GPA) was the indicator of self-reactivity to the prime. Study 1 involved a direct achievement goal prime, whereas Studies 2 and 3 involved indirect priming techniques. In all 3 experiments, greater academic exaggeration following the achievement goal prime (but not the control prime) predicted better academic performance a semester later (based on official records). Study 4 demonstrated that the magnitude of students' GPA goals mediated the association between academic exaggeration and subsequent performance (1 year later). The fact that self-reactivity to a single achievement goal prime in the lab predicted later performance in "real life" suggests that individual differences in reactivity to a specific prime can signal much broader motivational orientations related to the primed goal. PMID:24588092

  16. Trends in Performance and Characteristics of Ultra-Stable Oscillators for Deep Space Radio Science Experiments

    NASA Technical Reports Server (NTRS)

    Asmar, Sami

    1997-01-01

    Telecommunication systems of spacecraft on deep space missions also function as instruments for Radio Science experiments. Radio scientists utilize the telecommunication links between spacecraft and Earth to examine very small changes in the phase/frequency, amplitude, and/or polarization of radio signals to investigate a host of physical phenomena in the solar system. Several missions augmented the radio communication system with an Ultra-Stable Oscillator (USO) in order to provide a highly stable reference signal for oneway downlink. This configuration is used in order to enable better investigations of the atmospheres of the planets occulting the line-of-sight to the spacecraft; one-way communication was required and the transponders' built-in auxiliary oscillators were neither sufficiently stable nor spectrally pure for the occultation experiments. Since Radio Science instrumentation is distributed between the spacecraft and the ground stations, the Deep Space Network (DSN) is also equipped to function as a world-class instrument for Radio Science research. For a detailed account of Radio Science experiments, methodology, key discoveries, and the DSN's historical contribution to the field, see Asmar and Renzetti (1993). The tools of Radio Science can be and have also been utilized in addressing several mission engineering challenges; e.g., characterization of spacecraft nutation and anomalous motion, antenna calibrations, and communications during surface landing phases. Since the first quartz USO was flown on Voyager, the technology has advanced significantly, affording future missions higher sensitivity in reconstructing the temperature pressure profiles of the atmospheres under study as well as other physical phenomena of interest to Radio Science. This paper surveys the trends in stability and spectral purity performance, design characteristics including size and mass, as well as cost and history of these clocks in space.

  17. The impact of the achievement motive on athletic performance in adolescent football players.

    PubMed

    Zuber, Claudia; Conzelmann, Achim

    2014-01-01

    Researchers largely agree that there is a positive relationship between achievement motivation and athletic performance, which is why the achievement motive is viewed as a potential criterion for talent. However, the underlying mechanism behind this relationship remains unclear. In talent and performance models, main effect, mediator and moderator models have been suggested. A longitudinal study was carried out among 140 13-year-old football talents, using structural equation modelling to determine which model best explains how hope for success (HS) and fear of failure (FF), which are the aspects of the achievement motive, motor skills and abilities that affect performance. Over a period of half a year, HS can to some extent explain athletic performance, but this relationship is not mediated by the volume of training, sport-specific skills or abilities, nor is the achievement motive a moderating variable. Contrary to expectations, FF does not explain any part of performance. Aside from HS, however, motor abilities and in particular skills also predict a significant part of performance. The study confirms the widespread assumption that the development of athletic performance in football depends on multiple factors, and in particular that HS is worth watching in the medium term as a predictor of talent. PMID:24041313

  18. Student Achievement for Whom? High-Performing and Still "Playing the Game," the Meaning of School Achievement among High Achieving African American Students

    ERIC Educational Resources Information Center

    Wiggan, Greg

    2014-01-01

    The preponderance of the research on African American students has generally focused on issues of school failure and underperformance. While the literature on high achieving Black students is sparse, very little is known about these students' school experiences and the meanings that they assign to achievement. Using student-based inquiry…

  19. Performance-based alternative assessments as a means of eliminating gender achievement differences on science tests

    NASA Astrophysics Data System (ADS)

    Brown, Norman Merrill

    1998-09-01

    Historically, researchers have reported an achievement difference between females and males on standardized science tests. These differences have been reported to be based upon science knowledge, abstract reasoning skills, mathematical abilities, and cultural and social phenomena. This research was designed to determine how mastery of specific science content from public school curricula might be evaluated with performance-based assessment models, without producing gender achievement differences. The assessment instruments used were Harcourt Brace Educational Measurement's GOALSsp°ler: A Performance-Based Measure of Achievement and the performance-based portion of the Stanford Achievement Testspcopyright, Ninth Edition. The identified independent variables were test, gender, ethnicity, and grade level. A 2 x 2 x 6 x 12 (test x gender x ethnicity x grade) factorial experimental design was used to organize the data. A stratified random sample (N = 2400) was selected from a national pool of norming data: N = 1200 from the GOALSsp°ler group and N = 1200 from the SAT9spcopyright group. The ANOVA analysis yielded mixed results. The factors of test, gender, ethnicity by grade, gender by grade, and gender by grade by ethnicity failed to produce significant results (alpha = 0.05). The factors yielding significant results were ethnicity, grade, and ethnicity by grade. Therefore, no significant differences were found between female and male achievement on these performance-based assessments.

  20. Predicting subjective vitality and performance in sports: the role of passion and achievement goals.

    PubMed

    Li, Chiung-Huang

    2010-06-01

    The major purpose of this study was to test the hypothesized paths from dualistic passions through achievement goals to subjective vitality and performance in sports. 645 high school athletes participated. The proposed structural equation model, with relationships between dualistic passions and subjective vitality and sports performance mediated by achievement goals, fit the data well, especially for mastery-approach and performance-approach goals. Harmonious and obsessive passions may lead athletes to high performance via the adoption of mastery-approach goals. However, these passions seem to have two paths influencing personal functioning: direct effects make players feel energetic, and indirect effects on subjective vitality through adoption of mastery-approach and performance-approach goals. PMID:20865990

  1. Performance on large-scale science tests: Item attributes that may impact achievement scores

    NASA Astrophysics Data System (ADS)

    Gordon, Janet Victoria

    Significant differences in achievement among ethnic groups persist on the eighth-grade science Washington Assessment of Student Learning (WASL). The WASL measures academic performance in science using both scenario and stand-alone question types. Previous research suggests that presenting target items connected to an authentic context, like scenario question types, can increase science achievement scores especially in underrepresented groups and thus help to close the achievement gap. The purpose of this study was to identify significant differences in performance between gender and ethnic subgroups by question type on the 2005 eighth-grade science WASL. MANOVA and ANOVA were used to examine relationships between gender and ethnic subgroups as independent variables with achievement scores on scenario and stand-alone question types as dependent variables. MANOVA revealed no significant effects for gender, suggesting that the 2005 eighth-grade science WASL was gender neutral. However, there were significant effects for ethnicity. ANOVA revealed significant effects for ethnicity and ethnicity by gender interaction in both question types. Effect sizes were negligible for the ethnicity by gender interaction. Large effect sizes between ethnicities on scenario question types became moderate to small effect sizes on stand-alone question types. This indicates the score advantage the higher performing subgroups had over the lower performing subgroups was not as large on stand-alone question types compared to scenario question types. A further comparison examined performance on multiple-choice items only within both question types. Similar achievement patterns between ethnicities emerged; however, achievement patterns between genders changed in boys' favor. Scenario question types appeared to register differences between ethnic groups to a greater degree than stand-alone question types. These differences may be attributable to individual differences in cognition

  2. Quantitative Guidance for Stove Usage and Performance to Achieve Health and Environmental Targets

    PubMed Central

    Chiang, Ranyee A.

    2015-01-01

    Background Displacing the use of polluting and inefficient cookstoves in developing countries is necessary to achieve the potential health and environmental benefits sought through clean cooking solutions. Yet little quantitative context has been provided on how much displacement of traditional technologies is needed to achieve targets for household air pollutant concentrations or fuel savings. Objectives This paper provides instructive guidance on the usage of cooking technologies required to achieve health and environmental improvements. Methods We evaluated different scenarios of displacement of traditional stoves with use of higher performing technologies. The air quality and fuel consumption impacts were estimated for these scenarios using a single-zone box model of indoor air quality and ratios of thermal efficiency. Results Stove performance and usage should be considered together, as lower performing stoves can result in similar or greater benefits than a higher performing stove if the lower performing stove has considerably higher displacement of the baseline stove. Based on the indoor air quality model, there are multiple performance–usage scenarios for achieving modest indoor air quality improvements. To meet World Health Organization guidance levels, however, three-stone fire and basic charcoal stove usage must be nearly eliminated to achieve the particulate matter target (< 1–3 hr/week), and substantially limited to meet the carbon monoxide guideline (< 7–9 hr/week). Conclusions Moderate health gains may be achieved with various performance–usage scenarios. The greatest benefits are estimated to be achieved by near-complete displacement of traditional stoves with clean technologies, emphasizing the need to shift in the long term to near exclusive use of clean fuels and stoves. The performance–usage scenarios are also provided as a tool to guide technology selection and prioritize behavior change opportunities to maximize impact. Citation

  3. Factors Influencing Student Achievement at a High-Performing Title I Elementary School

    ERIC Educational Resources Information Center

    Neimeier, Charlann K.

    2012-01-01

    Schools in America are required to provide all students with a quality education regardless of race, ethnicity, or socioeconomic background, demonstrated through test scores mandated by the No Child Left Behind Act. Knowledge about factors that influence students' academic performance and serve to reduce the achievement gap between Hispanic…

  4. Achievement Motivation Goals in Relation to Academic Performance in Traditional and Nontraditional College Students.

    ERIC Educational Resources Information Center

    Eppler, Marion; Harju, Beverly L.

    1997-01-01

    A study of the relationship between goal orientation and academic performance in 262 undergraduates, classified as traditional or nontraditional, found both groups rated themselves higher on learning goals than achievement goals, but nontraditional students endorsed learning goals more strongly. Goal orientations were a better predictor of…

  5. Performance-Approach Goal Effects on Achievement under Low versus High Challenge Conditions

    ERIC Educational Resources Information Center

    Senko, Corwin; Durik, Amanda M.; Patel, Lily; Lovejoy, Chelsea M.; Valentiner, David

    2013-01-01

    Two studies examined the effects of university students' achievement goals on performance under low versus high challenge conditions. The first was a laboratory experiment in which participants were assigned goals to pursue on a novel mathematics task alleged to be simple or complex to use. The second was a survey study in which students set goals…

  6. Supporting Instructional Improvement in Low-Performing Schools to Increase Students' Academic Achievement

    ERIC Educational Resources Information Center

    Bellei, Cristian

    2013-01-01

    This is an impact evaluation of the Technical Support to Failing Schools Program, a Chilean compensatory program that provided 4-year in-school technical assistance to low-performing schools to improve students' academic achievement. The author implemented a quasi-experimental design by using difference-in-differences estimation combined with…

  7. A Study of the Relationships Between Test Order, Physiological Arousal, and Intelligence and Achievement Test Performance.

    ERIC Educational Resources Information Center

    Nighswander, James K.; Beggs, Donald L.

    The relative predictive abilities of two indices of test anxiety were investigated. The galvanic skin response (GSR) and the Test Anxiety Scale for Children (TASC) were used as predictor variables for IQ and achievement test performance. The results of multiple linear regression analysis indicated that neither the TASC nor the GSR, combined over…

  8. Four Language Skills Performance, Academic Achievement, and Learning Strategy Use in Preservice Teacher Training Programs

    ERIC Educational Resources Information Center

    Shawer, Saad Fathy

    2016-01-01

    This article examines the differences in language learning strategies (LLS) use between preservice teachers of English as a foreign language (EFL) and Arabic as a second language (ASL). It also examines the relationship between LLS use and language performance (academic achievement and four language skills) among ASL students. The study made use…

  9. Gender, Geographic Locations, Achievement Goals and Academic Performance of Secondary School Students from Borno State, Nigeria

    ERIC Educational Resources Information Center

    Musa, Alice K.J.

    2013-01-01

    The paper examined gender, geography location, achievement goals and academic performance of senior secondary school students in Borno State, Nigeria. The sample consists of 827 students from 18 public boarding secondary schools across South and North of Borno State: 414 (50.1 per cent) males and 413 (49.9 per cent) are females; 414 (50.1 per…

  10. Using Self-Correction to Improve the Spelling Performance of Low-Achieving Third Graders.

    ERIC Educational Resources Information Center

    Wirtz, Connie L.; And Others

    1996-01-01

    Comparison of two spelling strategies (traditional versus self-correction) on spelling performance of six low-achieving third-grade students found the self-correction procedure more effective than the traditional condition and also helped students maintain their ability to correctly spell previously learned words. (Author/DB)

  11. Teaching to the Tails: Teacher Performance Pay and the Distribution of Student Achievement

    ERIC Educational Resources Information Center

    Loyalka, Prashant; Sylvia, Sean; Liu, Chengfang; Chu, James; Rozelle, Scott

    2015-01-01

    Growing evidence suggests that teachers in developing countries often have weak or misaligned incentives for improving student outcomes. In response, policymakers and researchers have proposed performance pay as a way to improve student outcomes by tying concrete measures like achievement scores to teacher pay. While evidence from randomized…

  12. Performance Concern, Contingent Self-Worth, and Responses to Repeated Achievement Failure in Second Graders

    ERIC Educational Resources Information Center

    Smiley, Patricia A.; Coulson, Sheri L.; Greene, Joelle K.; Bono, Katherine L.

    2010-01-01

    Individual differences in emotion, cognitions, and task choice following achievement failure are found among four- to seven-year-olds. However, neither performance deterioration during failure nor generalization after failure--aspects of the helpless pattern in 10-year-olds--have been reliably demonstrated in this age group. In the present study,…

  13. Marked for Success: Secondary School Performance and University Achievement in Biology

    ERIC Educational Resources Information Center

    Comer, Keith; Broght, Erik; Sampson, Kaylene

    2011-01-01

    Building on Shulruf, Hattie and Tumen (2008), this work examines the capacity of various National Certificate in Educational Achievement (NCEA)-derived models to predict first-year performance in Biological Sciences at a New Zealand university. We compared three models: (1) the "best-80" indicator as used by several New Zealand…

  14. Improving Achievement in Low-Performing Schools: Key Results for School Leaders

    ERIC Educational Resources Information Center

    Ward, Randolph E.; Burke, Mary Ann

    2004-01-01

    As accountability in schools becomes more crucial, educators are looking for comprehensive and innovative management practices that respond to challenges and realities of student academic achievement. In order to improve academic performance and the quality of instruction, the entire school community needs to be involved. This book provides six…

  15. The Influence of Overt Practice, Achievement Level, and Explanatory Style on Calibration Accuracy and Performance

    ERIC Educational Resources Information Center

    Bol, Linda; Hacker, Douglas J.; O'Shea, Patrick; Allen, Dwight

    2005-01-01

    The authors measured the influence of overt calibration practice, achievement level, and explanatory style on calibration accuracy and exam performance. Students (N = 356) were randomly assigned to either an overt practice or no-practice condition. Students in the overt practice condition made predictions and postdictions about their performance…

  16. Immigrant Children's Educational Achievement in Western Countries: Origin, Destination, and Community Effects on Mathematical Performance

    ERIC Educational Resources Information Center

    Levels, Mark; Dronkers, Jaap; Kraaykamp, Gerbert

    2008-01-01

    This article explores the extent to which macro-level characteristics of destination countries, origin countries, and immigrant communities help explain differences in immigrant children's educational achievement. Using data from the 2003 PISA survey, we analyze the mathematical performance of 7,403 pupils from 35 different origin countries in 13…

  17. Preparation and performance of novel thermally stable polyamide/PPENK composite nanofiltration membranes

    NASA Astrophysics Data System (ADS)

    Hu, Lijie; Zhang, Shouhai; Han, Runlin; Jian, Xigao

    2012-09-01

    Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na2SO4 > MgSO4 > Al2(SO4)3 > NaCl > MgCl2, which indicated a negative charge at the membrane surface. The flux and Na2SO4 rejection of PPENK composite membranes reached 57.9 L/m2 h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20 °C to 80 °C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h.

  18. The honeymoon effect in job performance - Temporal increases in the predictive power of achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.; Sawin, Linda L.; Carsrud, Alan L.

    1986-01-01

    Correlations between a job performance criterion and personality measures reflecting achievement motivation and an interpersonal orientation were examined at three points in time after completion of job training for a sample of airline reservations agents. Although correlations between the personality predictors and performance were small and nonsignificant for the 3-month period after beginning the job, by the end of six and eight months a number of significant relationships had emerged. Implications for the utility of personality measures in selection and performance prediction are discussed.

  19. High-Performance Inkjet-Printed Indium-Gallium-Zinc-Oxide Transistors Enabled by Embedded, Chemically Stable Graphene Electrodes.

    PubMed

    Secor, Ethan B; Smith, Jeremy; Marks, Tobin J; Hersam, Mark C

    2016-07-13

    Recent developments in solution-processed amorphous oxide semiconductors have established indium-gallium-zinc-oxide (IGZO) as a promising candidate for printed electronics. A key challenge for this vision is the integration of IGZO thin-film transistor (TFT) channels with compatible source/drain electrodes using low-temperature, solution-phase patterning methods. Here we demonstrate the suitability of inkjet-printed graphene electrodes for this purpose. In contrast to common inkjet-printed silver-based conductive inks, graphene provides a chemically stable electrode-channel interface. Furthermore, by embedding the graphene electrode between two consecutive IGZO printing passes, high-performance IGZO TFTs are achieved with an electron mobility of ∼6 cm(2)/V·s and current on/off ratio of ∼10(5). The resulting printed devices exhibit robust stability to aging in ambient as well as excellent resilience to thermal stress, thereby offering a promising platform for future printed electronics applications. PMID:27327555

  20. A physical education trial improves adolescents' cognitive performance and academic achievement: the EDUFIT study.

    PubMed

    Ardoy, D N; Fernández-Rodríguez, J M; Jiménez-Pavón, D; Castillo, R; Ruiz, J R; Ortega, F B

    2014-02-01

    To analyze the effects of an intervention focused on increasing the time and intensity of Physical Education (PE), on adolescents' cognitive performance and academic achievement. A 4-month group-randomized controlled trial was conducted in 67 adolescents from South-East Spain, 2007. Three classes were randomly allocated into control group (CG), experimental group 1 (EG1) and experimental group 2 (EG2). CG received usual PE (two sessions/week), EG1 received four PE sessions/week and EG2 received four PE sessions/week of high intensity. Cognitive performance (non-verbal and verbal ability, abstract reasoning, spatial ability, verbal reasoning and numerical ability) was assessed by the Spanish Overall and Factorial Intelligence Test, and academic achievement by school grades. All the cognitive performance variables, except verbal reasoning, increased more in EG2 than in CG (all P < 0.05). Average school grades (e.g., mathematics) increased more in EG2 than in CG. Overall, EG2 improved more than EG1, without differences between EG1 and CG. Increased PE can benefit cognitive performance and academic achievement. This study contributes to the current knowledge by suggesting that the intensity of PE sessions might play a role in the positive effect of physical activity on cognition and academic success. Future studies involving larger sample sizes should confirm or contrast these preliminary findings. PMID:23826633

  1. Mechanical and Electrical Performance of Thermally Stable Au-ZnO films

    DOE PAGESBeta

    Schoeppner, Rachel L.; Goeke, Ronald S.; Moody, Neville R.; Bahr, David F.

    2015-03-28

    The mechanical properties, thermal stability, and electrical performance of Au–ZnO composite thin films are determined in this work. The co-deposition of ZnO with Au via physical vapor deposition leads to grain refinement over that of pure Au; the addition of 0.1 vol.% ZnO reduces the as-grown grain size by over 30%. The hardness of the as-grown films doubles with 2% ZnO, from 1.8 to 3.6 GPa as measured by nanoindentation. Films with ZnO additions greater than 0.5% show no significant grain growth after annealing at 350 °C, while pure gold and smaller additions do exhibit grain growth and subsequent mechanicalmore » softening. Films with 1% and 2% ZnO show a decrease of approximately 50% in electrical resistivity and no change in hardness after annealing. A model accounting for both changes in the interface structure between dispersed ZnO particles and the Au matrix captures the changes in mechanical and electrical resistivity. Furthermore, the addition of 1–2% ZnO co-deposited with Au provides a method to create mechanically hard and thermally stable films with a resistivity less than 80 nΩ-m. Our results complement previous studies of other alloying systems, suggesting oxide dispersion strengthened (ODS) gold shows a desirable hardness–resistivity relationship that is relatively independent of the particular ODS chemistry.« less

  2. Mechanical and Electrical Performance of Thermally Stable Au-ZnO films

    SciTech Connect

    Schoeppner, Rachel L.; Goeke, Ronald S.; Moody, Neville R.; Bahr, David F.

    2015-03-28

    The mechanical properties, thermal stability, and electrical performance of Au–ZnO composite thin films are determined in this work. The co-deposition of ZnO with Au via physical vapor deposition leads to grain refinement over that of pure Au; the addition of 0.1 vol.% ZnO reduces the as-grown grain size by over 30%. The hardness of the as-grown films doubles with 2% ZnO, from 1.8 to 3.6 GPa as measured by nanoindentation. Films with ZnO additions greater than 0.5% show no significant grain growth after annealing at 350 °C, while pure gold and smaller additions do exhibit grain growth and subsequent mechanical softening. Films with 1% and 2% ZnO show a decrease of approximately 50% in electrical resistivity and no change in hardness after annealing. A model accounting for both changes in the interface structure between dispersed ZnO particles and the Au matrix captures the changes in mechanical and electrical resistivity. Furthermore, the addition of 1–2% ZnO co-deposited with Au provides a method to create mechanically hard and thermally stable films with a resistivity less than 80 nΩ-m. Our results complement previous studies of other alloying systems, suggesting oxide dispersion strengthened (ODS) gold shows a desirable hardness–resistivity relationship that is relatively independent of the particular ODS chemistry.

  3. Daily Online Testing in Large Classes: Boosting College Performance while Reducing Achievement Gaps

    PubMed Central

    Pennebaker, James W.; Gosling, Samuel D.; Ferrell, Jason D.

    2013-01-01

    An in-class computer-based system, that included daily online testing, was introduced to two large university classes. We examined subsequent improvements in academic performance and reductions in the achievement gaps between lower- and upper-middle class students in academic performance. Students (N = 901) brought laptop computers to classes and took daily quizzes that provided immediate and personalized feedback. Student performance was compared with the same data for traditional classes taught previously by the same instructors (N = 935). Exam performance was approximately half a letter grade above previous semesters, based on comparisons of identical questions asked from earlier years. Students in the experimental classes performed better in other classes, both in the semester they took the course and in subsequent semester classes. The new system resulted in a 50% reduction in the achievement gap as measured by grades among students of different social classes. These findings suggest that frequent consequential quizzing should be used routinely in large lecture courses to improve performance in class and in other concurrent and subsequent courses. PMID:24278176

  4. The effects of achievement goals on performance, enjoyment, and practice of a novel motor task.

    PubMed

    Kavussanu, Maria; Morris, Rebecca L; Ring, Christopher

    2009-10-01

    We examined the effects of trichotomous achievement goals on performance, enjoyment, and practice of a golf-putting task. Male (n = 39) and female (n = 63) undergraduate students participated in the experiment in exchange for course credit. Participants were assigned to a mastery, performance-approach, or performance-avoidance goal condition and completed seven blocks of 10 trials (one for baseline, four for the experimental phase, and two for the transfer phase) of a golf-putting task. Distance from the target was measured and performance measures of accuracy and consistency were calculated. Self-reported enjoyment during the baseline and experimental phases and practice during a 5-min period before and following the experimental task were also assessed. Performance accuracy and consistency improved similarly among the three groups. Individuals in all three conditions reported enjoying the task to the same extent. Mastery participants practiced for longer than performance-approach participants during the practice period. Performance-avoidance participants did not differ significantly from the other two groups. The three goals were equally effective in promoting performance and enjoyment of the golf-putting task. The differential practice results for the two performance goals suggest that they should be considered separately. PMID:19735037

  5. The effect of workshop groups on achievement goals and performance in biology: An outcome evaluation

    NASA Astrophysics Data System (ADS)

    Born, Wendi Kay

    This two-year quasi-experiment evaluated the effect of peer-led workshop groups on performance of minority and majority undergraduate biology students in a three-course series and investigated motivational explanations for performance differences. The workshop intervention used was modeled after a program pioneered by Treisman (1992) at the University of California. Majority volunteers randomly assigned to workshops (n = 61) performed between 1/2 and 1 standard deviation better than those assigned to the control group (n = 60; p < .05) in each quarter without spending more time studying. During Quarter 1, workshop minority students (n = 25) showed a pattern of increasing exam performance in comparison to historic control minority students (n = 21), who showed a decreasing pattern (p < .05). Although sex differences in biology performance were a focus of investigation, none were detected. Motivational predictions derived from the hierarchical model of approach and avoidance achievement motivation (Elliot & Church, 1997) were partially supported. Self-report survey measures of achievement goals, modeled after those used by Elliot and colleagues, were requested from all enrolled students. Volunteers (n = 121) reported higher average levels of approach and avoidance goals than nonvolunteers (n = 439; p < .05) and the relationship of goals to performance was moderated by volunteer status. Performance of volunteers was negatively related to avoidance of failure goals (r = .41, p < .01) and unrelated to performance approach goals. Performance of nonvolunteers was unrelated to avoidance of failure goals and positively related to performance approach goals (r = .28, p < .01). Mastery goals were unrelated to performance for all students. Results were inconsistent with Dweck and Leggett's (1988) theory of mastery vs. performance orientation, but were similar to results found by Elliot and colleagues. Contrary to hypotheses, motivational goals did not mediate performance for

  6. Performance of a Thermally Stable Polyaromatic Hydrocarbon in a Simulated Concentrating Solar Power Loop

    SciTech Connect

    McFarlane, Joanna; Bell, Jason R; Felde, David K; Joseph III, Robert Anthony; Qualls, A L; Weaver, Samuel P

    2014-01-01

    Polyaromatic hydrocarbon thermal fluids showing thermally stability to 600 C have been tested for solar thermal-power applications. Although static thermal tests showed promising results for 1-phenylnaphthalene, loop testing at temperatures to 450 C indicated that the fluid isomerized and degraded at a slow rate. In a loop with a temperature high enough to drive the isomerization, the higher melting point byproducts tended to condense onto cooler surfaces. So, as experienced in loop operation, eventually the internal channels of cooler components in trough solar electric generating systems, such as the waste heat rejection exchanger, may become coated or clogged affecting loop performance. Thus, pure 1-phenylnaphthalene, without addition of stabilizers, does not appear to be a fluid that would have a sufficiently long lifetime (years to decades) to be used in a loop at the temperatures greater than 500 C. The performance of a concentrating solar loop using high temperature fluids was modeled based on the National Renewable Laboratory Solar Advisory Model. It was determined that a solar-to-electricity efficiency of up to 30% and a capacity factor of near 60% could be achieved using a high efficiency collector and 12 h thermal energy storage.

  7. Social jetlag, academic achievement and cognitive performance: Understanding gender/sex differences.

    PubMed

    Díaz-Morales, Juan F; Escribano, Cristina

    2015-01-01

    Adolescents in high school suffer from circadian misalignment, undersleeping on weekdays and oversleeping on weekends. Since high schools usually impose early schedules, adolescents suffer from permanent social jetlag (SJL) and thus are a suitable population to study the effects of SJL on both academic and cognitive performance. In this study, 796 adolescents aged 12-16 years reported information about their sleep habits, morningness-eveningness (M-E), cognitive abilities and grade point average (GPA). Time in bed on both weekdays and weekends was not related to cognitive abilities, and only time in bed on weekdays was related to academic achievement. SJL was negatively related to academic achievement, cognitive abilities (except for vocabulary and verbal fluency abilities) and general cognitive ability (g), whereas M-E was slightly positively related to academic achievement and marginally negatively related to inductive reasoning. Results separated by sex/gender indicated that SJL may be more detrimental to girls' performance, as it was negatively related to a greater number of cognitive abilities and GPA. PMID:26061587

  8. Achieving performance breakthroughs in an HMO business process through quality planning.

    PubMed

    Hanan, K B

    1993-01-01

    Kaiser Permanente's Georgia Region commissioned a quality planning team to design a new process to improve payments to its suppliers and vendors. The result of the team's effort was a 73 percent reduction in cycle time. This team's experiences point to the advantages of process redesign as a quality planning model, as well as some general guidelines for its most effective use in teams. If quality planning project teams are carefully configured, sufficiently expert in the existing process, and properly supported by management, organizations can achieve potentially dramatic improvements in process performance using this approach. PMID:10130708

  9. Wind/tornado design criteria, development to achieve required probabilistic performance goals

    SciTech Connect

    Ng, D.S.

    1991-06-01

    This paper describes the strategy for developing new design criteria for a critical facility to withstand loading induced by the wind/tornado hazard. The proposed design requirements for resisting wind/tornado loads are based on probabilistic performance goals. The proposed design criteria were prepared by a Working Group consisting of six experts in wind/tornado engineering and meteorology. Utilizing their best technical knowledge and judgment in the wind/tornado field, they met and discussed the methodologies and reviewed available data. A review of the available wind/tornado hazard model for the site, structural response evaluation methods, and conservative acceptance criteria lead to proposed design criteria that has a high probability of achieving the required performance goals.

  10. Performance Achievements and Challenges for FELs based on Energy Recovered Linacs

    SciTech Connect

    Geoffrey Krafft

    2006-08-27

    During the past decade several groups have assembled free electron lasers based on energy recovered linacs (ERLs). Such arrangements have been built to obtain high average power electron and photon beams, by using high repetition rate beam pulses driving FEL oscillators. In this paper the performance of many existing and several proposed facilities from around the world are reviewed. Going forward, many questions must be addressed to achieve still better performance including: higher average current injectors, better optimized accelerating cavities, higher energy acceptance and lower loss beam recirculation systems, and better optical cavity designs for dealing with the optical beam power circulating in the ERL FELs. This paper presents some of the current thinking on each of these issues.

  11. A Comparison of Performance in Solving Arithmetical Word Problems by Children with Different Levels of Achievement in Mathematics and Reading

    ERIC Educational Resources Information Center

    Reikeras, Elin K. L.

    2009-01-01

    Performance in consistent arithmetical word problems was assessed in 941 pupils aged eight (N = 415), ten (N = 274), and thirteen (N = 252) classified in four achievement groups by standardised achievement tests: low achievement in both mathematics and reading (MLRL), in mathematics only (ML-only), in reading only (RL-only), and normal achievement…

  12. Efforts to achieve high-performance long-pulse operations in the EAST

    NASA Astrophysics Data System (ADS)

    Wan, Baonian; EAST Team; Collaborators

    2016-01-01

    To achieve long-pulse tokamak operation, sufficient current drive and self-generated current are required, with the challenges of the exhaust of the heat from the divertor plates. Experiments have proven that lower hybrid current drive (LHCD) can broaden the divertor power footprint and cause the splitting of the strike point current and hence reduce the peak heat flux on the divertors. Edge localized mode (ELM) mitigation can be realized by supersonic molecule beam injection (SMBI), modulated LHCD, lithium granule and aerosol injection, as well as resonant magnetic perturbation (RMP). Enhanced transport by an electrostatic edge coherent mode at the pedestal region is observed in the ELM mitigated plasmas by LHCD. Long-pulse H-mode plasmas in the small ELMy regime have been demonstrated by a combination of ELM mitigation techniques and the optimization of the plasma confinement performance. These newly achieved H-mode scenarios by using features of LHCD in the control of steady-state peak heat flux and transient heat flux due to ELMs may offer a promising regime for further EAST long-pulse high-performance operation and be applicable to ITER.

  13. Achieving High Performance in AC-Field Driven Organic Light Sources

    PubMed Central

    Xu, Junwei; Carroll, David L.; Smith, Gregory M.; Dun, Chaochao; Cui, Yue

    2016-01-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m2 with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today’s OLEDs in performance. PMID:27063414

  14. Achieving High Performance in AC-Field Driven Organic Light Sources.

    PubMed

    Xu, Junwei; Carroll, David L; Smith, Gregory M; Dun, Chaochao; Cui, Yue

    2016-01-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m(2) with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today's OLEDs in performance. PMID:27063414

  15. Achieving High Performance in AC-Field Driven Organic Light Sources

    NASA Astrophysics Data System (ADS)

    Xu, Junwei; Carroll, David L.; Smith, Gregory M.; Dun, Chaochao; Cui, Yue

    2016-04-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m2 with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today’s OLEDs in performance.

  16. An Examination of Secondary School Students' Academic Achievement in Science Course and Achievement Scores in Performance Assignments with Regard to Different Variables: A Boarding School Example

    ERIC Educational Resources Information Center

    Bozdogan, Aykut Emre; Günaydin, Esra; Okur, Alperen

    2014-01-01

    The aim of the study is to explore the academic achievement and performance tasks of students studying in a regional primary boarding school in science course with regard to different variables. The study was carried out via survey method and total 96 students, 57 of them boarding students and 39 of them non-boarding students studying in the 5th,…

  17. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    ERIC Educational Resources Information Center

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  18. On the achievable performance using variable geometry active secondary suspension systems in commercial vehicles

    NASA Astrophysics Data System (ADS)

    Evers, Willem-Jan; Besselink, Igo; Teerhuis, Arjan; Nijmeijer, Henk

    2011-10-01

    There is a need to further improve driver comfort in commercial vehicles. The variable geometry active suspension offers an interesting option to achieve this in an energy efficient way. However, the optimal control strategy and the overal performance potential remains unclear. The aim of this paper is to quantify the level of performance improvement that can theoretically be obtained by replacing a conventional air sprung cabin suspension design with a variable geometry active suspension. Furthermore, the difference between the use of a linear quadratic (LQ) optimal controller and a classic skyhook controller is investigated. Hereto, an elementary variable geometry actuator model and experimentally validated four degrees of freedom quarter truck model are adopted. The results show that the classic skyhook controller gives a relatively poor performance while a comfort increase of 17-28% can be obtained with the LQ optimal controller, depending on the chosen energy weighting. Furthermore, an additional 75% comfort increase and 77% energy cost reduction can be obtained, with respect to the fixed gain energy optimal controller, using condition-dependent control gains. So, it is concluded that the performance potential using condition-dependent controllers is huge, and that the use of the classic skyhook control strategy should, in general, be avoided when designing active secondary suspensions for commercial vehicles.

  19. A Study of Identification and Achievement Profiles of Performance Task-Identified Gifted Students over 6 Years

    ERIC Educational Resources Information Center

    VanTassel-Baska, Joyce; Feng, Annie Xuemei; de Brux, Elizabeth

    2007-01-01

    This study examined the trend of identification and achievement patterns of performance task-identified students over a span of 6 years (2000-2005), in comparison to profiles of students who were identified exclusively through traditional ability and achievement tests. The study findings suggested that the performance-based protocols were…

  20. WWC Quick Review of the Report "The Effect of Performance-Pay in Little Rock, Arkansas on Student Achievement"

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2008

    2008-01-01

    This review examined a study designed to evaluate whether the Achievement Challenge Pilot Project, a performance-pay program for teachers, improved the academic achievement of elementary school students. Study authors reported higher student test score gains for students in schools that implemented the performance- pay program than for students in…

  1. High-performance TSD bits improve penetration rate. [Thermally Stable Diamond

    SciTech Connect

    Cohen, J.H.; Maurer, W.C. ); Westcott, P.A. )

    1993-04-12

    Optimizing the number, size, and orientation of clutters on thermally stable diamond (TSD) bits increases penetration rate and extends bit life. The use of optimized TSD (also commonly referred to as thermally stable product or TSP) bits on high-power drilling motors can greatly reduce drilling time for harsh-environment wells, such as deep gas wells. The power delivered to the rock governs drilling rate, and at high speed the optimized TSD bits are capable of effectively delivering power to drill the rock. This article reviews a 3-year project to develop advanced thermally stable diamond bits that can operate at a power level 5-10 times greater than that typically delivered by conventional rotary drilling. These bits are designed to operate on advanced drilling motors that drill three to six times faster than rotary drilling. These advanced bits and motors are especially designed for use in slim-hole and horizontal drilling applications. The TSD bit design parameters which were varied during the tests were cutter size, shape, density (number of cutters), and orientation. Drilling tests in limestone, sandstone, marble, and granite blocks showed that these optimized bits drilled many of these rocks at 500-1,000 ft/hr compared to 50-100 ft/hr for conventional rotary drilling. A sensitivity model showed that doubling the rate of penetration significantly reduced the time to drill a well and reduced costs by 13 %.

  2. Achieving realistic performance and decison-making capabilities in computer-generated air forces

    NASA Astrophysics Data System (ADS)

    Banks, Sheila B.; Stytz, Martin R.; Santos, Eugene, Jr.; Zurita, Vincent B.; Benslay, James L., Jr.

    1997-07-01

    For a computer-generated force (CGF) system to be useful in training environments, it must be able to operate at multiple skill levels, exhibit competency at assigned missions, and comply with current doctrine. Because of the rapid rate of change in distributed interactive simulation (DIS) and the expanding set of performance objectives for any computer- generated force, the system must also be modifiable at reasonable cost and incorporate mechanisms for learning. Therefore, CGF applications must have adaptable decision mechanisms and behaviors and perform automated incorporation of past reasoning and experience into its decision process. The CGF must also possess multiple skill levels for classes of entities, gracefully degrade its reasoning capability in response to system stress, possess an expandable modular knowledge structure, and perform adaptive mission planning. Furthermore, correctly performing individual entity behaviors is not sufficient. Issues related to complex inter-entity behavioral interactions, such as the need to maintain formation and share information, must also be considered. The CGF must also be able to acceptably respond to unforeseen circumstances and be able to make decisions in spite of uncertain information. Because of the need for increased complexity in the virtual battlespace, the CGF should exhibit complex, realistic behavior patterns within the battlespace. To achieve these necessary capabilities, an extensible software architecture, an expandable knowledge base, and an adaptable decision making mechanism are required. Our lab has addressed these issues in detail. The resulting DIS-compliant system is called the automated wingman (AW). The AW is based on fuzzy logic, the common object database (CODB) software architecture, and a hierarchical knowledge structure. We describe the techniques we used to enable us to make progress toward a CGF entity that satisfies the requirements presented above. We present our design and

  3. Mice and rats achieve similar levels of performance in an adaptive decision-making task

    PubMed Central

    Jaramillo, Santiago; Zador, Anthony M.

    2014-01-01

    Two opposing constraints exist when choosing a model organism for studying the neural basis of adaptive decision-making: (1) experimental access and (2) behavioral complexity. Available molecular and genetic approaches for studying neural circuits in the mouse fulfill the first requirement. In contrast, it is still under debate if mice can perform cognitive tasks of sufficient complexity. Here we compare learning and performance of mice and rats, the preferred behavioral rodent model, during an acoustic flexible categorization two-alternative choice task. The task required animals to switch between two categorization definitions several times within a behavioral session. We found that both species achieved similarly high performance levels. On average, rats learned the task faster than mice, although some mice were as fast as the average rat. No major differences in subjective categorization boundaries or the speed of adaptation between the two species were found. Our results demonstrate that mice are an appropriate model for the study of the neural mechanisms underlying adaptive decision-making, and suggest they might be suitable for other cognitive tasks as well. PMID:25278849

  4. An initial assessment of the performance achieved by the Seasat-1 radar altimeter

    NASA Technical Reports Server (NTRS)

    Townsend, W. F.

    1980-01-01

    The results of an initial on-orbit engineering assessment of the performance achieved by the radar altimeter system flown on SEASAT-1 are presented. Additionally, the general design characteristics of this system are discussed and illustrations of altimeter data product are provided. The instrument consists of a 13.5 GHz monostatic radar system that tracks in range only using a one meter parabolic antenna pointed at the satellite nadir. Two of its unique features are a linear FM transmitter with 320 MHz bandwidth which yields a 3.125 nanosecond time delay resolution, and microprocessor implemented closed loop range tracking, automatic gain control (AGC), and real time estimation of significant wave height (SWH). Results presented show that the altimeter generally performed in accordance with its orginal performance requirments of measuring altitude to a precision of less the 10 cm RMS, significant wave height to an accuracy of + or - 0.5 m or 10%, whichever is greater, and ocean backscatter coefficient to an accuracy of + or - 1 db, all over an SWH range of 1 to 20 meters.

  5. Comparison of Performance Achievement Award Recognition With Primary Stroke Center Certification for Acute Ischemic Stroke Care

    PubMed Central

    Fonarow, Gregg C.; Liang, Li; Smith, Eric E.; Reeves, Mathew J.; Saver, Jeffrey L.; Xian, Ying; Hernandez, Adrian F.; Peterson, Eric D.; Schwamm, Lee H.

    2013-01-01

    Background Hospital certification and recognition programs represent 2 independent but commonly used systems to distinguish hospitals, yet they have not been directly compared. This study assessed acute ischemic stroke quality of care measure conformity by hospitals receiving Primary Stroke Center (PSC) certification and those receiving the American Heart Association's Get With The Guidelines‐Stroke (GWTG‐Stroke) Performance Achievement Award (PAA) recognition. Methods and Results The patient and hospital characteristics as well as performance/quality measures for acute ischemic stroke from 1356 hospitals participating in the GWTG‐Stroke Program 2010–2012 were compared. Hospitals were classified as PAA+/PSC+ (hospitals n=410, patients n=169 302), PAA+/PSC− (n=415, n=129 454), PAA−/PSC+ (n=88, n=26 386), and PAA−/PSC− (n=443, n=75 565). A comprehensive set of stroke measures were compared with adjustment for patient and hospital characteristics. Patient characteristics were similar by PAA and PSC status but PAA−/PSC− hospitals were more likely to be smaller and nonteaching. Measure conformity was highest for PAA+/PSC+ and PAA+/PSC− hospitals, intermediate for PAA−/PSC+ hospitals, and lowest for PAA−/PSC− hospitals (all‐or‐none care measure 91.2%, 91.2%, 84.3%, and 76.9%, respectively). After adjustment for patient and hospital characteristics, PAA+/PSC+, PAA+/PSC−, and PAA−/PSC+ hospitals had 3.15 (95% CIs 2.86 to 3.47); 3.23 (2.93 to 3.56) and 1.72 (1.47 to 2.00), higher odds for providing all indicated stroke performance measures to patients compared with PAA−/PSC− hospitals. Conclusions While both PSC certification and GWTG‐Stroke PAA recognition identified hospitals providing higher conformity with care measures for patients hospitalized with acute ischemic stroke, PAA recognition was a more robust identifier of hospitals with better performance. PMID:24125846

  6. Highly Stable and Conductive Microcapsules for Enhancement of Joule Heating Performance

    PubMed Central

    2016-01-01

    Nanocarbons show great promise for establishing the next generation of Joule heating systems, but suffer from the limited maximum temperature due to precociously convective heat dissipation from electrothermal system to surrounding environment. Here we introduce a strategy to eliminate such convective heat transfer by inserting highly stable and conductive microcapsules into the electrothermal structures. The microcapsule is composed of encapsulated long-chain alkanes and graphene oxide/carbon nanotube hybrids as core and shell material, respectively. Multiform carbon nanotubes in the microspheres stabilize the capsule shell to resist volume-change-induced rupture during repeated heating/cooling process, and meanwhile enhance the thermal conductance of encapsulated alkanes which facilitates an expeditious heat exchange. The resulting microcapsules can be homogeneously incorporated in the nanocarbon-based electrothermal structures. At a dopant of 5%, the working temperature can be enhanced by 30% even at a low voltage and moderate temperature, which indicates a great value in daily household applications. Therefore, the stable and conductive microcapsule may serve as a versatile and valuable dopant for varieties of heat generation systems. PMID:27002594

  7. Highly Stable and Conductive Microcapsules for Enhancement of Joule Heating Performance.

    PubMed

    Zheng, Zhaoliang; Jin, Jidong; Xu, Guang-Kui; Zou, Jianli; Wais, Ulrike; Beckett, Alison; Heil, Tobias; Higgins, Sean; Guan, Lunhui; Wang, Ying; Shchukin, Dmitry

    2016-04-26

    Nanocarbons show great promise for establishing the next generation of Joule heating systems, but suffer from the limited maximum temperature due to precociously convective heat dissipation from electrothermal system to surrounding environment. Here we introduce a strategy to eliminate such convective heat transfer by inserting highly stable and conductive microcapsules into the electrothermal structures. The microcapsule is composed of encapsulated long-chain alkanes and graphene oxide/carbon nanotube hybrids as core and shell material, respectively. Multiform carbon nanotubes in the microspheres stabilize the capsule shell to resist volume-change-induced rupture during repeated heating/cooling process, and meanwhile enhance the thermal conductance of encapsulated alkanes which facilitates an expeditious heat exchange. The resulting microcapsules can be homogeneously incorporated in the nanocarbon-based electrothermal structures. At a dopant of 5%, the working temperature can be enhanced by 30% even at a low voltage and moderate temperature, which indicates a great value in daily household applications. Therefore, the stable and conductive microcapsule may serve as a versatile and valuable dopant for varieties of heat generation systems. PMID:27002594

  8. Silica-Based, Hyper-Crosslinked Acid Stable Stationary Phases for High Performance Liquid Chromatography

    PubMed Central

    Zhang, Yu; Luo, Hao; Carr, Peter W.

    2011-01-01

    A new family of Hyper-Crosslinked (HC) phases has been recently introduced for use under very aggressive acid conditions including those encountered in ultra-fast, high temperature Two-Dimensional Liquid Chromatography (2DLC). This type of stationary phase showed significantly enhanced acid and thermal stability compared to the most acid stable, commercial RPLC phases. In addition, the use of “orthogonal” chemistry to make surface-confined polymer networks ensures good reproducibility and high efficiency. One of the most interesting features of the HC phases is the ability to derivatize the surface aromatic groups with various functional groups. This led to the development of a family of hyper-crosslinked phases possessing a wide variety of chromatographic selectivities by attaching hydrophobic (e.g. –C8), ionizable (e.g. -COOH, -SO3H), aromatic (e.g. –toluene) or polar (e.g. -OH) species to the aromatic polymer network. HC reversed phases with various degrees of hydrophobicity and mixed-mode HC phases with added strong and weak cation exchange sites have been synthesized, characterized and applied. These silica-based acid-stable HC phases, with their attractive chromatographic properties, should be very useful in the separations of bases or biological analytes in acidic media, especially at elevated temperatures. This work reviews the prior research on HC phases and introduces a novel HC phase made by alternative chemistry. PMID:21906745

  9. Achieving palliative care research efficiency through defining and benchmarking performance metrics

    PubMed Central

    Lodato, Jordan E.; Aziz, Noreen; Bennett, Rachael E.; Abernethy, Amy P.; Kutner, Jean S.

    2014-01-01

    Purpose of Review Research efficiency is gaining increasing attention in the research enterprise, including palliative care research. The importance of generating meaningful findings and translating these scientific advances to improved patient care creates urgency in the field to address well-documented system inefficiencies. The Palliative Care Research Cooperative Group (PCRC) provides useful examples for ensuring research efficiency in palliative care. Recent Findings Literature on maximizing research efficiency focuses on the importance of clearly delineated process maps, working instructions, and standard operating procedures (SOPs) in creating synchronicity in expectations across research sites. Examples from the PCRC support these objectives and suggest that early creation and employment of performance metrics aligned with these processes are essential to generate clear expectations and identify benchmarks. These benchmarks are critical in effective monitoring and ultimately the generation of high quality findings that are translatable to clinical populations. Prioritization of measurable goals and tasks to ensure that activities align with programmatic aims is critical. Summary Examples from the PCRC affirm and expand the existing literature on research efficiency, providing a palliative care focus. Operating procedures, performance metrics, prioritization, and monitoring for success should all be informed by and inform the process map to achieve maximum research efficiency. PMID:23080309

  10. Performance Trajectories and Performance Gaps as Achievement Effect-Size Benchmarks for Educational Interventions. MDRC Working Papers on Research Methodology

    ERIC Educational Resources Information Center

    Bloom, Howard S.; Hill, Carolyn J.; Black, Alison Rebeck; Lipsey, Mark W.

    2008-01-01

    This paper explores two complementary approaches to developing empirical benchmarks for achievement effect sizes in educational interventions. The first approach characterizes the natural developmental progress in achievement by students from one year to the next as effect sizes. Data for seven nationally standardized achievement tests show large…

  11. "Standards"-based Mathematics Curricula and Secondary Students' Performance on Standardized Achievement Tests

    ERIC Educational Resources Information Center

    Harwell, Michael R.; Post, Thomas R.; Maeda, Yukiko; Davis, Jon D.; Cutler, Arnold L.; Andersen, Edwin; Kahan, Jeremy A.

    2007-01-01

    The current study examined the mathematical achievement of high school students enrolled for 3 years in one of three NSF funded "Standards"-based curricula (IMP, CMIC, MMOW). The focus was on traditional topics in mathematics as measured by subtests of a standardized achievement test and a criterion-referenced test of mathematics achievement.…

  12. Measuring Emotions in Students' Learning and Performance: The Achievement Emotions Questionnaire (AEQ)

    ERIC Educational Resources Information Center

    Pekrun, Reinhard; Goetz, Thomas; Frenzel, Anne C.; Barchfeld, Petra; Perry, Raymond P.

    2011-01-01

    Aside from test anxiety scales, measurement instruments assessing students' achievement emotions are largely lacking. This article reports on the construction, reliability, internal validity, and external validity of the Achievement Emotions Questionnaire (AEQ) which is designed to assess various achievement emotions experienced by students in…

  13. Mathematics Achievement Level Testing as a Predictor of Academic Performance and Retention in Engineering Students.

    ERIC Educational Resources Information Center

    Durio, Helen F.; And Others

    Scholastic aptitude, mathematics achievement, and high school rank were used as college entry predictors of achievement in a foundation engineering curriculum for 1,779 freshmen enrolling in engineering at the University of Texas at Austin during the years 1974-77. Achievement in the foundation engineering curriculum was measured by taking…

  14. High-performance heterogeneous catalysis with surface-exposed stable metal nanoparticles

    PubMed Central

    Huang, Ning; Xu, Yanhong; Jiang, Donglin

    2014-01-01

    Protection of metal nanoparticles from agglomeration is critical for their functions and applications. The conventional method for enhancing their stability is to cover them with passivation layers to prevent direct contact. However, the presence of a protective shell blocks exposure of the metal species to reactants, thereby significantly impeding the nanoparticles' utility as catalysts. Here, we report that metal nanoparticles can be prepared and used in a surface-exposed state that renders them inherently catalytically active. This strategy is realised by spatial confinement and electronic stabilisation with a dual-module mesoporous and microporous three-dimensional π-network in which surface-exposed nanoparticles are crystallised upon in situ reduction. The uncovered palladium nanoparticles serve as heterogeneous catalysts that are exceptionally active in water, catalyse unreactive aryl chlorides for straightforward carbon–carbon bond formation and are stable for repeated use in various types of cross couplings. Therefore, our results open new perspectives in developing practical heterogeneous catalysts. PMID:25427425

  15. Monitoring the performance of community forestry to achieve REDD+ goals through geospatial methods

    NASA Astrophysics Data System (ADS)

    Gilani, H.; Krishna Gautam, S.; Murthy, M. S. R.; Koju, U. A.; Uddin, K.; Karky, B.

    2014-11-01

    Measurement, reporting and verification (MRV) is included in the Cancun, Mexico, in 2010 under climate change agreements, as one of the most critical elements necessary for the successful implementation of any reducing of emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+) mechanism. Community forestry is recognised as a successful model for conserving forests, raising awareness among local people and decentralising the forest governance practices. In the world, Nepal is considered as a leader in community-based forest management. This study conducted in 16 community forests (2384.76 ha) of Kayar Khola watershed (8002 ha) of Chitwan district, Nepal. In this paper, satellite images IKONOS-2 (2002) and GeoEye-1 (2009 & 2012) were used which have 1 m and 0.5 m ground spatial distance (GSD) respectively. Geographic information system (GIS) participatory approach was embraced for the boundaries delineation of community forests. Geographic object-based image analysis (GEOBIA) classification technique was performed and overall accuracy 94 % with 92.91 % producer's and 96.2 % user's accuracies. Through change matrix method, 25.49 ha and 1.08 ha area deforested while 179.84 ha and 33.24 ha reforested in two time periods 2002-2009 and 2009-2012 respectively. Overall within 16 community forests, "Close broadleaved to Open broadleaved" 4.42 ha and 4 ha area is transferred between 2002-2009 and 2009-2012 respectively. While "Open broadleaved to Close broadleaved" 29.25 ha and 31.1 ha area is converted in seven years (2002-2009) and in three years (2009-2012) respectively. Coefficient of determination (R2) 0.833 achieved through a line-intercept transect between number of segmented and observed tree crowns. Maximum numbers of the counted trees exist below 20 m2, which show the forest of the study area is not mature and has capacity to

  16. Stable compactifications

    SciTech Connect

    Accetta, F.S.; Gleiser, M.; Holman, R.; Kolb, E.W.

    1986-03-01

    We show that compactifications of theories with extra dimensions are unstable if due to monopole configurations of an antisymmetric tensor field balanced against one-loop Casimir corrections. In the case of ten dimensional supergravity, it is possible, at least for a portion of the phase space, to achieve a stable compactification without fine-tuning by including the contribution of fermionic condensates to the monopole configurations. 23 refs., 2 figs.

  17. On the Value of Intrinsic Rather than Traditional Achievement Goals for Performing Artists: A Short-Term Prospective Study

    ERIC Educational Resources Information Center

    Lacaille, Natalie; Koestner, Richard; Gaudreau, Patrick

    2007-01-01

    Educational researchers have examined the effect of achievement goals on student performance, and suggest that both mastery goals and performance-approach goals are beneficial, whereas performance-avoidance goals are harmful. Recent research proposes that these results may not be generalized in the domain of music. The purpose of the present study…

  18. Measuring Metacognition and Reaction Time: Further Findings on the Performances of General Education, Low-Achieving, and Institutionally Raised Students

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.; Abdullah, Ahmad A.

    2010-01-01

    The purpose of this study was to use the picture format to examine in depth the metacognitive performances and reaction time in general education, low-achieving, and institutionally raised students. Results revealed that institutionally raised students, unlike low-achieving students, took significantly the longest reaction time to finish the test…

  19. How Stable Is Stable?

    ERIC Educational Resources Information Center

    Baehr, Marie

    1994-01-01

    Provides a problem where students are asked to find the point at which a soda can floating in some liquid changes its equilibrium between stable and unstable as the soda is removed from the can. Requires use of Newton's first law, center of mass, Archimedes' principle, stable and unstable equilibrium, and buoyant force position. (MVL)

  20. A hydrological modeling framework for defining achievable performance standards for pesticides.

    PubMed

    Rousseau, Alain N; Lafrance, Pierre; Lavigne, Martin-Pierre; Savary, Stéphane; Konan, Brou; Quilbé, Renaud; Jiapizian, Paul; Amrani, Mohamed

    2012-01-01

    This paper proposes a hydrological modeling framework to define achievable performance standards (APSs) for pesticides that could be attained after implementation of recommended management actions, agricultural practices, and available technologies (i.e., beneficial management practices [BMPs]). An integrated hydrological modeling system, Gestion Intégrée des Bassins versants à l'aide d'un Système Informatisé, was used to quantify APSs for six Canadian watersheds for eight pesticides: atrazine, carbofuran, dicamba, glyphosate, MCPB, MCPA, metolachlor, and 2,4-D. Outputs from simulation runs to predict pesticide concentration under current conditions and in response to implementation of two types of beneficial management practices (reduced pesticide application rate and 1- to 10-m-wide edge-of-field and/or riparian buffer strips, implemented singly or in combination) showed that APS values for scenarios with BMPs were less than those for current conditions. Moreover, APS values at the outlet of watersheds were usually less than ecological thresholds of good condition, when available. Upstream river reaches were at greater risk of having concentrations above a given ecological thresholds because of limited stream flows and overland loads of pesticides. Our integrated approach of "hydrological modeling-APS estimation-ecotoxicological significance" provides the most effective interpretation possible, for management and education purposes, of the potential biological impact of predicted pesticide concentrations in rivers. PMID:22218173

  1. A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

    SciTech Connect

    James, Conrad D.; Schiess, Adrian B.; Howell, Jamie; Baca, Micheal J.; Partridge, L. Donald; Finnegan, Patrick Sean; Wolfley, Steven L.; Dagel, Daryl James; Spahn, Olga Blum; Harper, Jason C.; Pohl, Kenneth Roy; Mickel, Patrick R.; Lohn, Andrew; Marinella, Matthew

    2013-10-01

    The human brain (volume=1200cm3) consumes 20W and is capable of performing>10%5E16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m%5E3 and 3MW, giving the brain a 10%5E12 advantage in operations/s/W/cm%5E3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

  2. The relationship between medical students’ epistemological beliefs and achievement on a clinical performance examination

    PubMed Central

    Oh, Sun-A; Chung, Eun-Kyung; Han, Eui-Ryoung; Woo, Young-Jong; Kevin, Deiter

    2016-01-01

    Purpose: This study was to explore the relationship between clinical performance examination (CPX) achievement and epistemological beliefs to investigate the potentials of epistemological beliefs in ill-structured medical problem solving tasks. Methods: We administered the epistemological beliefs questionnaire (EBQ) to fourth-year medical students and correlated the results with their CPX scores. The EBQ comprised 61 items reflecting five belief systems: certainty of knowledge, source of knowledge, rigidity of learning, ability to learn, and speed of knowledge acquisition. The CPX included scores for history taking, physical examination, and patient-physician interaction. Results: The higher epistemological beliefs group obtained significantly higher scores on the CPX with regard to history taking and patient-physician interaction. The epistemological beliefs scores on certainty of knowledge and source of knowledge were significantly positively correlated with patient-physician interaction. The epistemological beliefs scores for ability to learn were significantly positively correlated with those for history taking, physical examination, and patient-physician interaction. Conclusion: Students with more sophisticated and advanced epistemological beliefs stances used more comprehensive and varied approaches in the patient-physician interaction. Therefore, educational efforts that encourage discussions pertaining to epistemological views should be considered to improve clinical reasoning and problem-solving competence in the clinic setting. PMID:26838566

  3. Performance of Learning Disabled and Low Achieving Secondary Students on Formal Features of a Paragraph-Writing Task.

    ERIC Educational Resources Information Center

    Moran, Mary Ross

    1981-01-01

    Writing samples were analyzed for syntactic maturity, productivity and word selection; for conventions such as tense and number markers and number agreement; and for spelling, punctuation, and capitalization. Only spelling performance proved significantly different in favor of low achievers. (Author)

  4. The effects of training and competition on achievement goals, motivational responses, and performance in a golf-putting task.

    PubMed

    van de Pol P, K C; Kavussanu, Maria; Ring, Christopher

    2012-12-01

    This study examined whether (a) training and competition influence achievement goals, effort, enjoyment, tension, and performance; (b) achievement goals mediate the effects of training and competition on effort, enjoyment, tension, and performance; and (c) the context influences the relationships between goals and effort, enjoyment, tension, and performance. Participants (32 males, 28 females; M age = 19.12 years) performed a golf-putting task in a training condition and a competition condition and completed measures of goal involvement, effort, enjoyment, and tension; putting performance was also measured. Both task and ego involvement varied across training and competition, and variation in ego involvement explained variation in effort and enjoyment between these conditions. Ego involvement positively predicted effort in training and performance in competition, and interacted positively with task involvement to predict effort and enjoyment in competition. Our findings suggest that the distinction between training and competition is a valuable one when examining individuals' achievement motivation. PMID:23204359

  5. Thermocouples of molybdenum and iridium alloys for more stable vacuum-high temperature performance

    NASA Technical Reports Server (NTRS)

    Morris, J. F. (Inventor)

    1978-01-01

    Thermocouples providing stability and performance reliability in systems involving high temperatures and vacuums by employing a bimetallic thermocouple sensor are described. Each metal of the sensor is selected from a group of metals comprising molybdenum and iridium and alloys containing only those two metals. The molybdenum, iridium thermocouple sensor alloys provide bare metal thermocouple sensors having advantageous vapor pressure compatibility and performance characteristics. The compatibility and physical characteristics of the thermocouple sensor alloys result in improved emf, temperature properties and thermocouple hot junction performance.

  6. Lead dioxide film sonoelectrodeposition in acidic media: Preparation and performance of stable practical anodes.

    PubMed

    Sáez, V; Esclapez, M D; Frías-Ferrer, A J; Bonete, P; Tudela, I; Díez-García, M I; González-García, J

    2011-07-01

    Practical lead dioxide anodes have been obtained by electrodeposition on glassy carbon and titanium substrates in the presence and in the absence of an ultrasound field. The films obtained by mechanical agitation on glassy carbon are strongly improved when the electrodeposition process is carried out with the ultrasound field, providing adherent deposits free from nodules and stress, but with pores appearing occasionally. These enhanced properties were not achieved by mechanical conditions, even when optimization of temperature, current density, additives and geometrical aspects was attempted. The best practical anodes were obtained by sonoelectrodeposition using specially treated titanium as substrate, providing comparable behavior to commercial electrodes. PMID:21195010

  7. Thermocouples of tantalum and rhenium alloys for more stable vacuum-high temperature performance

    NASA Technical Reports Server (NTRS)

    Morris, J. F. (Inventor)

    1977-01-01

    Thermocouples of the present invention provide stability and performance reliability in systems involving high temperatures and vacuums by employing a bimetallic thermocouple sensor wherein each metal of the sensor is selected from a group of metals comprising tantalum and rhenium and alloys containing only those two metals. The tantalum, rhenium thermocouple sensor alloys provide bare metal thermocouple sensors having advantageous vapor pressure compatibilities and performance characteristics. The compatibility and physical characteristics of the thermocouple sensor alloys of the present invention result in improved emf, temperature properties and thermocouple hot junction performance. The thermocouples formed of the tantalum, rhenium alloys exhibit reliability and performance stability in systems involving high temperatures and vacuums and are adaptable to space propulsion and power systems and nuclear environments.

  8. The CryoSat Interferometer after 6 years in orbit: calibration and achievable performance

    NASA Astrophysics Data System (ADS)

    Scagliola, Michele; Fornari, Marco; De Bartolomei, Maurizio; Bouffard, Jerome; Parrinello, Tommaso

    2016-04-01

    The main payload of CryoSat is a Ku-band pulse width limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter). When commanded in SARIn (synthetic aperture radar interferometry) mode, through coherent along-track processing of the returns received from two antennas, the interferometric phase related to the first arrival of the echo is used to retrieve the angle of arrival of the scattering in the across-track direction. In fact, the across-track echo direction can be derived by exploiting the precise knowledge of the baseline vector (i.e. the vector between the two antennas centers of phase) and simple geometry. The end-to-end calibration strategy for the CryoSat interferometer consists on in-orbit calibration campaigns following the approach described in [1]. From the beginning of the CryoSat mission, about once a year the interferometer calibration campaigns have been periodically performed by rolling left and right the spacecraft of about ±0.4 deg. This abstract is aimed at presenting our analysis of the calibration parameters and of the achievable performance of the CryoSat interferometer over the 6 years of mission. Additionally, some further studies have been performed to assess the accuracy of the roll angle computed on ground as function of the aberration (the apparent displacement of a celestial object from its true position, caused by the relative motion of the observer and the object) correction applied to the attitude quaternions, provided by the Star Tracker mounted on-board. In fact, being the roll information crucial to obtain an accurate estimate of the angle of arrival, the data from interferometer calibration campaigns have been used to verify how the application of the aberration correction affects the roll information and, in turns, the measured angle of arrival. [1] Galin, N.; Wingham, D.J.; Cullen, R.; Fornari, M.; Smith, W.H.F.; Abdalla, S., "Calibration of the CryoSat-2 Interferometer and Measurement of Across

  9. Tracking Student Achievement in Music Performance: Developing Student Learning Objectives for Growth Model Assessments

    ERIC Educational Resources Information Center

    Wesolowski, Brian C.

    2015-01-01

    Student achievement growth data are increasingly used for assessing teacher effectiveness and tracking student achievement in the classroom. Guided by the student learning objective (SLO) framework, music teachers are now responsible for collecting, tracking, and reporting student growth data. Often, the reported data do not accurately reflect the…

  10. The Interactive Effects of Personal Achievement Goals and Performance Feedback in an Undergraduate Science Class

    ERIC Educational Resources Information Center

    Muis, Krista R.; Ranellucci, John; Franco, Gina M.; Crippen, Kent J.

    2013-01-01

    The authors explored whether manipulating feedback influenced cognition, motivation, and achievement in an undergraduate chemistry course. They measured students' ("N" = 250) achievement goals, test anxiety, self-efficacy, and metacognitive strategy use at the beginning and end of the semester. After completing the first set of…

  11. Achievement First: Developing a Teacher Performance Management System That Recognizes Excellence

    ERIC Educational Resources Information Center

    Curtis, Rachel

    2011-01-01

    Teachers are the single most important school-related factor in students' learning, and improving student learning is the single most important goal at Achievement First (AF), a fast-growing public charter school network in the Northeast. To achieve this goal, the AF team has worked to establish a common understanding of effective instructional…

  12. To Master or Perform? Exploring Relations between Achievement Goals and Conceptual Change Learning

    ERIC Educational Resources Information Center

    Ranellucci, John; Muis, Krista R.; Duffy, Melissa; Wang, Xihui; Sampasivam, Lavanya; Franco, Gina M.

    2013-01-01

    Background: Research is needed to explore conceptual change in relation to achievement goal orientations and depth of processing. Aims: To address this need, we examined relations between achievement goals, use of deep versus shallow processing strategies, and conceptual change learning using a think-aloud protocol. Sample and Method:…

  13. Cohort versus Non-Cohort High School Students' Math Performance: Achievement Test Scores and Coursework

    ERIC Educational Resources Information Center

    Parke, Carol S.; Keener, Dana

    2011-01-01

    The purpose of this study is to compare multiple measures of mathematics achievement for 1,378 cohort students who attended the same high school in a district from 9th to 12th grade with non-cohort students in each grade level. Results show that mobility had an impact on math achievement. After accounting for gender, ethnicity, and SES, adjusted…

  14. Performance-Based Music Ensembles' Effects on Academic Achievement: A Correlational Study

    ERIC Educational Resources Information Center

    Stevenson, Timothy Francis

    2013-01-01

    As increasing student achievement levels for all learners continues to drive the focus of education, identifying strategies and opportunities to accomplish this goal becomes progressively more important. This study explored the concepts of self-efficacy, self-efficacy for self-regulated learning, and self-efficacy for academic achievement in…

  15. How Do Relationships Influence Student Achievement? Understanding Student Performance from a General, Social Psychological Standpoint

    ERIC Educational Resources Information Center

    Aspelin, Jonas

    2012-01-01

    This article explores the influence of relationships on student achievement by examining empirical evidence and by adopting a social psychological theory. Initially, the issue is addressed from a national, Swedish context. Thereafter, two general questions are raised: (1) What is the influence of relationships on student achievement, according to…

  16. Tailoring indium oxide nanocrystal synthesis conditions for air-stable high-performance solution-processed thin-film transistors.

    PubMed

    Swisher, Sarah L; Volkman, Steven K; Subramanian, Vivek

    2015-05-20

    Semiconducting metal oxides (ZnO, SnO2, In2O3, and combinations thereof) are a uniquely interesting family of materials because of their high carrier mobilities in the amorphous and generally disordered states, and solution-processed routes to these materials are of particular interest to the printed electronics community. Colloidal nanocrystal routes to these materials are particularly interesting, because nanocrystals may be formulated with tunable surface properties into stable inks, and printed to form devices in an additive manner. We report our investigation of an In2O3 nanocrystal synthesis for high-performance solution-deposited semiconductor layers for thin-film transistors (TFTs). We studied the effects of various synthesis parameters on the nanocrystals themselves, and how those changes ultimately impacted the performance of TFTs. Using a sintered film of solution-deposited In2O3 nanocrystals as the TFT channel material, we fabricated devices that exhibit field effect mobility of 10 cm(2)/(V s) and an on/off current ratio greater than 1 × 10(6). These results outperform previous air-stable nanocrystal TFTs, and demonstrate the suitability of colloidal nanocrystal inks for high-performance printed electronics. PMID:25915094

  17. Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate into silver ion using 2 % trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were ...

  18. Performance evaluation of iterative reconstruction algorithms for achieving CT radiation dose reduction - a phantom study.

    PubMed

    Dodge, Cristina T; Tamm, Eric P; Cody, Dianna D; Liu, Xinming; Jensen, Corey T; Wei, Wei; Kundra, Vikas; Rong, John

    2016-01-01

    The purpose of this study was to characterize image quality and dose performance with GE CT iterative reconstruction techniques, adaptive statistical iterative recon-struction (ASiR), and model-based iterative reconstruction (MBIR), over a range of typical to low-dose intervals using the Catphan 600 and the anthropomorphic Kyoto Kagaku abdomen phantoms. The scope of the project was to quantitatively describe the advantages and limitations of these approaches. The Catphan 600 phantom, supplemented with a fat-equivalent oval ring, was scanned using a GE Discovery HD750 scanner at 120 kVp, 0.8 s rotation time, and pitch factors of 0.516, 0.984, and 1.375. The mA was selected for each pitch factor to achieve CTDIvol values of 24, 18, 12, 6, 3, 2, and 1 mGy. Images were reconstructed at 2.5 mm thickness with filtered back-projection (FBP); 20%, 40%, and 70% ASiR; and MBIR. The potential for dose reduction and low-contrast detectability were evaluated from noise and contrast-to-noise ratio (CNR) measurements in the CTP 404 module of the Catphan. Hounsfield units (HUs) of several materials were evaluated from the cylinder inserts in the CTP 404 module, and the modulation transfer function (MTF) was calculated from the air insert. The results were con-firmed in the anthropomorphic Kyoto Kagaku abdomen phantom at 6, 3, 2, and 1mGy. MBIR reduced noise levels five-fold and increased CNR by a factor of five compared to FBP below 6mGy CTDIvol, resulting in a substantial improvement in image quality. Compared to ASiR and FBP, HU in images reconstructed with MBIR were consistently lower, and this discrepancy was reversed by higher pitch factors in some materials. MBIR improved the conspicuity of the high-contrast spatial resolution bar pattern, and MTF quantification confirmed the superior spatial resolution performance of MBIR versus FBP and ASiR at higher dose levels. While ASiR and FBP were relatively insensitive to changes in dose and pitch, the spatial resolution for MBIR

  19. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2011-01-01

    For many NASA missions, remote sensing is a critical application that supports activities such as environmental monitoring, planetary science, structural shape and health monitoring, non-destructive evaluation, etc. The utility of the remote sensing devices themselves is greatly increased if they are passive that is, they do not require any on-board power supply such as batteries and if they can be identified uniquely during the sensor interrogation process. Additional passive sensor characteristics that enable greater utilization in space applications are small size and weight, long read ranges with low interrogator power, ruggedness, and operability in extreme environments (vacuum, extreme high/low temperature, high radiation, etc.) In this paper, we consider one very promising passive sensor technology, called surface acoustic wave (SAW) radio-frequency identification (RFID), that satisfies all of these criteria. Although SAW RFID tags have great potential for use in numerous space-based remote sensing applications, the limited collision resolution capability of current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? What are the

  20. High-performance air-stable n-type carbon nanotube transistors with erbium contacts.

    PubMed

    Shahrjerdi, Davood; Franklin, Aaron D; Oida, Satoshi; Ott, John A; Tulevski, George S; Haensch, Wilfried

    2013-09-24

    So far, realization of reproducible n-type carbon nanotube (CNT) transistors suitable for integrated digital applications has been a difficult task. In this work, hundreds of n-type CNT transistors from three different low work function metals-erbium, lanthanum, and yttrium-are studied and benchmarked against p-type devices with palladium contacts. The crucial role of metal type and deposition conditions is elucidated with respect to overall yield and performance of the n-type devices. It is found that high oxidation rates and sensitivity to deposition conditions are the major causes for the lower yield and large variation in performance of n-type CNT devices with low work function metal contacts. Considerable improvement in device yield is attained using erbium contacts evaporated at high deposition rates. Furthermore, the air-stability of our n-type transistors is studied in light of the extreme sensitivity of these metals to oxidation. PMID:24006886

  1. The Relationship Between Achievement and Laboratory Skills to the Number of Experiments Performed by the High School Chemistry Student.

    ERIC Educational Resources Information Center

    Grosmark, Jay Waldo

    The purpose of this study was to determine the effectiveness of doubling the laboratory experiments and time in the laboratory on student achievement, performance on laboratory skills, and attitude toward high school chemistry. One hundred forty-three students were assigned either of two treatments. All students performed the same basic…

  2. A Comprehensive Review of the Literature on the Effects of Breakfast on Mental Performance and Scholastic Achievement.

    ERIC Educational Resources Information Center

    Purnell, James P.

    A review of the literature on the effects of breakfast on mental performance and scholastic achievement reveals a dichotomy between the theoretical and the empirical literature. Whereas theoretical considerations maintain that breakfast makes a significant difference in mental performance in the late morning hours, empirical evidence can be…

  3. GUIDELINES FOR INDUSTRIAL BOILER PERFORMANCE IMPROVEMENT. (BOILER ADJUSTMENT PROCEDURES TO MINIMIZE AIR POLLUTION AND TO ACHIEVE EFFICIENT USE OF FUEL)

    EPA Science Inventory

    Recommended procedures for improving industrial boiler performance to minimize air pollution and to achieve efficient use of fuel are given. It is intended for use by industrial boiler operators to perform an efficiency and emissions tune-up on boilers firing gas, oil, or coal. P...

  4. Temperature-stable lithium niobate electro-optic Q-switch for improved cold performance

    NASA Astrophysics Data System (ADS)

    Jundt, Dieter H.

    2014-10-01

    Lithium niobate (LN) is commonly used as an electro optic (EO) Q-switch material in infrared targeting lasers because of its relatively low voltage requirements and low cost compared to other crystals. A common challenge is maintaining good performance at the sub-freezing temperatures often experienced during flight. Dropping to low temperature causes a pyro-electric charge buildup on the optical faces that leads to birefringence non-uniformity and depolarization resulting in poor hold-off and premature lasing. The most common solution has been to use radioactive americium to ionize the air around the crystal and bleed off the charge, but the radioactive material requires handling and disposal procedures that can be problematic. We have developed a superior solution that is now being implemented by multiple defense system suppliers. By applying a low level thermo-chemical reduction to the LN crystal optical faces we induce a small conductivity that allows pyro-charges to dissipate. As the material gets more heavily treated, the capacity to dissipate charges improves, but the corresponding optical absorption also increases, causing insertion loss. Even though typical high gain targeting laser systems can tolerate a few percent of added loss, the thermo-chemical processing needs to be carefully optimized. We describe the results of our process optimization to minimize the insertion loss while still giving effective charge dissipation. Treatment is performed at temperatures below 500°C and a conductivity layer less than 0.5mm in depth is created that is uniform across the optical aperture. Because the conductivity is thermally activated, the charge dissipation is less effective at low temperature, and characterization needs to be performed at cold temperatures. The trade-off between optical insertion loss and potential depolarization due to low temperature operation is discussed and experimental results on the temperature dependence of the dissipation time and the

  5. A Stable Whole Building Performance Method for Standard 90.1

    SciTech Connect

    Rosenberg, Michael I.; Eley, Charles

    2013-05-01

    Wouldn’t it be great if a single energy model could be used to demonstrate minimum code compliance, green code compliance, establish a Leadership in Energy and Environmental Design (LEED) rating, and determine eligibility for federal tax and utility incentives? Even better, what if the basic rules for creating those models did not change every few years? This paper descibes a recently proposed addendum to ASHRAE/ANSI/IES Standard 90.1 aims to meet those goals. Addendum BM establishes the Performance Rating Method found in Appendix G of Standard 90.1 as a new method of compliance while maintaining its traditional use in gauging the efficiency of beyond code buildings. Furthermore, Addendum BM sets a common baseline building that does not change with each update to the standard.

  6. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    NASA Technical Reports Server (NTRS)

    Barton Richard J.

    2012-01-01

    current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: (1) What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? (2) What are the differences in optimal or near-optimal interrogator designs between noise-limited environments and interference-limited environments? (3) What are the performance characteristics of different interrogator designs in term of parameters such as transmitter power level, range, and number of interfering tags? In this paper, we will present the results of a research effort aimed at providing at least partial answers to all of these questions.

  7. Amphiphilic (Phthalocyaninato) (Porphyrinato) Europium Triple-Decker Nanoribbons with Air-Stable Ambipolar OFET Performance.

    PubMed

    Lu, Guang; Kong, Xia; Ma, Pan; Wang, Kang; Chen, Yanli; Jiang, Jianzhuang

    2016-03-01

    An amphiphilic mixed (phthalocyaninato) (porphyrinato) europium(III) triple-decker complex [Pc(OPh)8]Eu[Pc(OPh)8]Eu[TP(C≡CCOOH)PP] (1) with potential ambipolar semiconducting HOMO and LUMO energy levels has been designed, synthesized, and characterized. The OFET devices fabricated by quasi-Langmuir-Shäfer (QLS) technique at the air/water interface with nanoparticle morphology display hole mobility of 7.0 × 10(-7) cm(2) V(-1) s(-1) and electron mobility of 7.5 × 10(-7) cm(2) V(-1) s(-1), which reflects its ambipolar semiconducting nature. However, the performance of the devices fabricated via a "phase-transfer" method from n-hexane with one-dimensional nanoribbon morphology was significantly improved by 3-6 orders of magnitude in terms of hole and electron mobilities, 0.11 and 4 × 10(-4) cm(2) V(-1) s(-1), due to the enhanced π-π interaction in the direction perpendicular to the tetrapyrrole rings associated with the formation of a dimeric supramolecular structure building block depending on the intermolecular hydrogen bonding between the neighboring triple-decker molecules in the one-dimensional nanoribbons. PMID:26894989

  8. Stable expression of silencing-suppressor protein enhances the performance and longevity of an engineered metabolic pathway.

    PubMed

    Naim, Fatima; Shrestha, Pushkar; Singh, Surinder P; Waterhouse, Peter M; Wood, Craig C

    2016-06-01

    Transgenic engineering of plants is important in both basic and applied research. However, the expression of a transgene can dwindle over time as the plant's small (s)RNA-guided silencing pathways shut it down. The silencing pathways have evolved as antiviral defence mechanisms, and viruses have co-evolved viral silencing-suppressor proteins (VSPs) to block them. Therefore, VSPs have been routinely used alongside desired transgene constructs to enhance their expression in transient assays. However, constitutive, stable expression of a VSP in a plant usually causes pronounced developmental abnormalities, as their actions interfere with endogenous microRNA-regulated processes, and has largely precluded the use of VSPs as an aid to stable transgene expression. In an attempt to avoid the deleterious effects but obtain the enhancing effect, a number of different VSPs were expressed exclusively in the seeds of Arabidopsis thaliana alongside a three-step transgenic pathway for the synthesis of arachidonic acid (AA), an ω-6 long chain polyunsaturated fatty acid. Results from independent transgenic events, maintained for four generations, showed that the VSP-AA-transformed plants were developmentally normal, apart from minor phenotypes at the cotyledon stage, and could produce 40% more AA than plants transformed with the AA transgene cassette alone. Intriguingly, a geminivirus VSP, V2, was constitutively expressed without causing developmental defects, as it acts on the siRNA amplification step that is not part of the miRNA pathway, and gave strong transgene enhancement. These results demonstrate that VSP expression can be used to protect and enhance stable transgene performance and has significant biotechnological application. PMID:26628000

  9. Spectral analysis software improves confidence in plant and soil water stable isotope analyses performed by isotope ratio infrared spectroscopy (IRIS).

    PubMed

    West, A G; Goldsmith, G R; Matimati, I; Dawson, T E

    2011-08-30

    Previous studies have demonstrated the potential for large errors to occur when analyzing waters containing organic contaminants using isotope ratio infrared spectroscopy (IRIS). In an attempt to address this problem, IRIS manufacturers now provide post-processing spectral analysis software capable of identifying samples with the types of spectral interference that compromises their stable isotope analysis. Here we report two independent tests of this post-processing spectral analysis software on two IRIS systems, OA-ICOS (Los Gatos Research Inc.) and WS-CRDS (Picarro Inc.). Following a similar methodology to a previous study, we cryogenically extracted plant leaf water and soil water and measured the δ(2)H and δ(18)O values of identical samples by isotope ratio mass spectrometry (IRMS) and IRIS. As an additional test, we analyzed plant stem waters and tap waters by IRMS and IRIS in an independent laboratory. For all tests we assumed that the IRMS value represented the "true" value against which we could compare the stable isotope results from the IRIS methods. Samples showing significant deviations from the IRMS value (>2σ) were considered to be contaminated and representative of spectral interference in the IRIS measurement. Over the two studies, 83% of plant species were considered contaminated on OA-ICOS and 58% on WS-CRDS. Post-analysis, spectra were analyzed using the manufacturer's spectral analysis software, in order to see if the software correctly identified contaminated samples. In our tests the software performed well, identifying all the samples with major errors. However, some false negatives indicate that user evaluation and testing of the software are necessary. Repeat sampling of plants showed considerable variation in the discrepancies between IRIS and IRMS. As such, we recommend that spectral analysis of IRIS data must be incorporated into standard post-processing routines. Furthermore, we suggest that the results from spectral analysis be

  10. Do Children in Montessori Schools Perform Better in the Achievement Test? A Taiwanese Perspective

    ERIC Educational Resources Information Center

    Peng, Hsin-Hui; Md-Yunus, Sham'ah

    2014-01-01

    The study examines whether elementary school students in Taiwan who had received Montessori education achieved significantly higher scores on tests of language arts, math, and social studies than students who attended non-Montessori elementary programs. One hundred ninety six children in first, second, and third grade participated in the study.…

  11. Improving Low Achievers' Academic Performance at University by Changing the Social Value of Mastery Goals

    ERIC Educational Resources Information Center

    Dompnier, Benoît; Darnon, Céline; Meier, Emanuele; Brandner, Catherine; Smeding, Annique; Butera, Fabrizio

    2015-01-01

    Recent research has shown that, in a university context, mastery goals are highly valued and that students may endorse these goals either because they believe in their utility (i.e., social utility), in which case mastery goals are positively linked to achievement, or to create a positive image of themselves (i.e., social desirability), in which…

  12. Performance Report for Project CLASS (Chinese Language Achievement through Sequential Study), 1998.

    ERIC Educational Resources Information Center

    Hu, Xue-mei

    Project CLASS (Chinese Language Achievement through Sequential Study), a federally-funded program, introduced the study of Chinese language and culture at Queen Ka'ahumanu Elementary School (Hawaii), forming the foundation of an instructional program to be continued through middle and high school, to meet state foreign language standards. In its…

  13. The Relationship between Victimization at School and Achievement: The Cusp Catastrophe Model for Reading Performance

    ERIC Educational Resources Information Center

    Sideridis, Georgios D.; Antoniou, Faye; Stamovlasis, Dimitrios; Morgan, Paul L.

    2013-01-01

    We evaluated the relationship between victimization and academic achievement from a nonlinear perspective using a cusp catastrophe model. Participants were 62 students with identified learning disabilities (LD) using statewide criteria in Greece. Students participated in a 2-year cohort-sequential design. Reading assessments involved measures of…

  14. The Relationship between Performance on the Wepman Auditory Discrimination Test and Reading Achievement among Adolescents.

    ERIC Educational Resources Information Center

    Simpson, Robert G.; And Others

    1984-01-01

    The purpose of this study was to investigate the relationship between auditory discrimination, as measured by the Wepman Auditory Discrimination Test, and reading achievement, as measured by the Woodcock Reading Mastery Tests. After controlling for intelligence, there was little more than a random relationship between auditory discrimination and…

  15. Differentiating Low Performance of the Gifted Learner: Achieving, Underachieving, and Selective Consuming Students

    ERIC Educational Resources Information Center

    Figg, Stephanie D.; Rogers, Karen B.; McCormick, John; Low, Renae

    2012-01-01

    The study aimed to empirically verify findings from qualitative studies that showed selective consumers could be distinguished from underachievers with regard to academic self-perception and thinking style preference. Participants, gifted males from an independent secondary boys' school in Sydney, Australia, were categorized as achieving,…

  16. High Achievement on Advanced Placement Exams: The Relationship of School-Level Contextual Factors to Performance

    ERIC Educational Resources Information Center

    Burney, Virginia H.

    2010-01-01

    The purpose of the study was to identify school- and district-level variables that relate to advanced academic achievement, as defined by the ratio of number of scores of 3, 4, or 5 on Advanced Placement exams to school enrollment. The study initially included 46 variables for 339 public high schools in one Midwestern state. Hierarchical linear…

  17. Understanding Student Goal Orientation Tendencies to Predict Student Performance: A 2x2 Achievement Goal Orientation

    ERIC Educational Resources Information Center

    Miller, Mark Alan

    2013-01-01

    The study tested the 2X2 model of the Achievement Goal Orientation (AGO) theory in a military technical training environment while using the Air Force Officers Qualifying Test's academic aptitude score to control for the differences in the students' academic aptitude. The study method was quantitative and the design was correlational.…

  18. Standard Errors of Proportions Used in Reporting Changes in School Performance with Achievement Levels.

    ERIC Educational Resources Information Center

    Arce-Ferrer, Alvaro; Frisbie, David A.; Kolen, Michael J.

    2002-01-01

    Studies of the achievement test results for about 490 school districts at grade 4 and about 420 districts at grade 5 show that the error variance of estimates of change at the school level is large enough to interfere with interpretations of annual change estimates. (SLD)

  19. Predicting End-of-Year Achievement Test Performance: A Comparison of Assessment Methods

    ERIC Educational Resources Information Center

    Kettler, Ryan J.; Elliott, Stephen N.; Kurz, Alexander; Zigmond, Naomi; Lemons, Christopher J.; Kloo, Amanda; Shrago, Jacqueline; Beddow, Peter A.; Williams, Leila; Bruen, Charles; Lupp, Lynda; Farmer, Jeanie; Mosiman, Melanie

    2014-01-01

    Motivated by the multiple-measures clause of recent federal policy regarding student eligibility for alternate assessments based on modified academic achievement standards (AA-MASs), this study examined how scores or combinations of scores from a diverse set of assessments predicted students' end-of-year proficiency status on statewide…

  20. Quality After-School Programming and Its Relationship to Achievement-Related Behaviors and Academic Performance

    ERIC Educational Resources Information Center

    Grassi, Annemarie M.

    2012-01-01

    The purpose of this study is to understand the relationship between quality social support networks developed through high quality afterschool programming and achievement amongst middle school and high school aged youth. This study seeks to develop a deeper understanding of how quality after-school programs influence a youth's developmental…

  1. Reversed-phase high-performance liquid chromatography of the stable electrophoretic fractions of soil humic acids

    NASA Astrophysics Data System (ADS)

    Trubetskoi, O. A.; Trubetskaya, O. E.

    2015-02-01

    Reversed-phase high-performance liquid chromatography (RP-HPLC) has been used for the hydrophobicity analysis of soil humic acids and their stable electrophoretic fractions A, B, and C + D preliminarily prepared by the combination of gel permeation chromatography on Sephadex with polyacrylamide gel electrophoresis. In two humic acid preparations of different genesis, the electrophoretic fraction A of the larger molecular size was the most hydrophobic (60-73% of the fraction was irreversibly adsorbed on a hydrophobic reversed-phase (RF) column C18), and the fraction C + D of the smallest molecular size was the most hydrophilic. The fraction B of medium size occupied an intermediate position (33-47% of the fraction was irreversibly adsorbed on the column). The use of RP-HPLC allowed for the first time detecting the hydrophobic electrophoretic fraction A of the largest molecular size mainly composed of aliphatic long-chained hydrocarbon, protein, and carbohydrate fragments in soil humic acids. Data on the degree of hydrophobicity and the earlier obtained physicochemical characteristics of stable electrophoretic fractions are discussed in terms of the supramolecular and macromolecular structure of soil humic acids.

  2. Associations between Achievement Goal Orientations and Academic Performance Among Students at a UK Pharmacy School

    PubMed Central

    Hanna, Lezley-Anne; Hanna, Alan; Hall, Karen

    2015-01-01

    Objective. To ascertain goal orientations of pharmacy students and establish whether associations exist between academic performance, gender, or year of study. Methods. Goal orientations were assessed using a validated questionnaire. Respondents were categorized as high or low performers based on university grades. Associations and statistical significance were ascertained using parametric and nonparametric tests and linear regression, as appropriate. Results. A response rate of 60.7% was obtained. High performers were more likely to be female than male. The highest mean score was for mastery approach; the lowest for work avoidance. The mean score for work avoidance was significantly greater for low performers than for high performers and for males than for females. First-year students were most likely to have top scores in mastery and performance approaches. Conclusion. It is encouraging that the highest mean score was for mastery approach orientation, as goal orientation may play a role in academic performance of pharmacy students. PMID:26396273

  3. Facile synthesis of vanadium nitride/nitrogen-doped graphene composite as stable high performance anode materials for supercapacitors

    NASA Astrophysics Data System (ADS)

    Balamurugan, Jayaraman; Karthikeyan, Gopalsamy; Thanh, Tran Duy; Kim, Nam Hoon; Lee, Joong Hee

    2016-03-01

    Novel vanadium nitride/nitrogen-doped graphene (VN/NG) composite was fabricated and used as stable high performance anode materials for supercapacitors. The VN/NG composite anode material exhibited excellent rate capability, outstanding cycling stability, and superior performance. FE-SEM and TEM studies of VN/NG composite revealed that ultra-thin VN nanostructures were homogeneously distributed on flexible NG nanosheets. The NG provided a highly conductive network to boost the charge transport involved during the capacitance generation and also aided the dispersion of nanostructured VN within the NG network. The synergetic VN/NG composite exhibited an ultra-high specific capacitance of 445 F g-1 at 1 Ag-1 with a wide operation window (-1.2 to 0 V) and showed outstanding rate capability (98.66% capacity retention after 10,000 cycles at 10 Ag-1). The VN/NG electrode offered a maximum energy density (∼81.73 Wh kg-1) and an ultra-high power density (∼28.82 kW kg-1 at 51.24 Wh kg-1). The cycling performance of the VN/NG composite was superior to that of pure VN nanostructure. These finding open a new path way to the designated fabrication of VN/NG composite as anode materials in the development of high performance energy storage devices.

  4. PEDOT gate electrodes with PVP/Al2O3 dielectrics for stable high-performance organic TFTs

    NASA Astrophysics Data System (ADS)

    Lee, Young Kyu; Maniruzzaman, Md.; Lee, Chiyoung; Lee, Mi Jung; Lee, Eun-Gu; Lee, Jaegab

    2013-11-01

    A poly(3,4-ethylenedioxythiophene) (PEDOT) gate electrode on a polyestersulfone (PES) substrate was used to fabricate inverted staggered pentacene organic thin film transistors (OTFTs). The PEDOT gate formed on the PES substrate exhibited semi-transparency, high conductivity, and excellent adhesion to the substrate. Prior to the deposition of poly-4-vinyl phenol (PVP) dielectrics, a thin Al2O3 layer (12 nm) was coated onto a PEDOT electrode, providing an effective barrier against inter-diffusion between the PVP dielectrics and the underlying PEDOT gate electrode, and against moisture penetration through the PES substrate. This led to stable high-performance OTFTs consisting of a PEDOT gate electrode and PVP/Al2O3 dielectrics. The combined PVP/Al2O3 dielectrics with PEDOT gate electrodes were successfully implemented in flexible organic TFTs that exhibit excellent compatibility with flexible electronics.

  5. Nursing to achieve organizational performance: Consider the role of nursing intellectual capital.

    PubMed

    Harris, Alexandra

    2016-05-01

    The success and performance of healthcare organizations relies on the strategic management of knowledge. Nursing Intellectual Capital (NIC) has emerged as a concept involving nursing knowledge resources that create value in healthcare organizations. This article aims to discuss the importance of considering knowledge resources in the context of healthcare performance, with specific reference to NIC. Reflections are then provided on how leaders can look to advance NIC for improved performance. PMID:27060807

  6. Patterns and predictors of adolescent academic achievement and performance in a sample of children with attention-deficit/hyperactivity disorder.

    PubMed

    Langberg, Joshua M; Molina, Brooke S G; Arnold, L Eugene; Epstein, Jeffery N; Altaye, Mekibib; Hinshaw, Stephen P; Swanson, James M; Wigal, Timothy; Hechtman, Lily

    2011-01-01

    The current study examined predictors of academic achievement, measured by standardized test scores, and performance, measured by school grades, in adolescents (Mn age = 16.8) who met diagnostic criteria for Attention-Deficit/Hyperactivity Disorder (ADHD)-Combined type in early childhood (Mn age = 8.5; N = 579). Several mediation models were also tested to determine whether ADHD medication use, receipt of special education services, classroom performance, homework completion, or homework management mediated the relationship between symptoms of ADHD and academic outcomes. Childhood predictors of adolescent achievement differed from those for performance. Classroom performance and homework management mediated the relationship between symptoms of inattention and academic outcomes. PMID:21722025

  7. Examining Relationships between Achievement Goals, Study Strategies, and Class Performance in Educational Psychology

    ERIC Educational Resources Information Center

    Cao, Li; Nietfeld, John L.

    2007-01-01

    This mixed methods study examined the relationships between students' learning goals, performance goals, study strategies, and test performances over a 14-week undergraduate course in educational psychology. Sixty undergraduate students provided goals at the beginning of the semester and reflected on their goals, study strategies, and test…

  8. Relationship between High School and College Performance by Maryland Students. Student Outcome and Achievement Report.

    ERIC Educational Resources Information Center

    Maryland State Higher Education Commission, Annapolis.

    This study examined the relationship between students' academic performance in high school vis-a-vis their performance in the first year at college. The study analyzed data on students who graduated from Maryland high schools in the 1994-95 academic year and who were enrolled in 2- and 4-year Maryland public institutions or in one of 11…

  9. The Role of Citizenship Performance in Academic Achievement and Graduate Employability

    ERIC Educational Resources Information Center

    Poropat, Arthur E.

    2011-01-01

    Purpose: Employability is a major educational goal, but employability programmes emphasise skill development, while employers value performance. Education acts as a model for employment, so educational performance assessment should be aligned with employment models. Consequently, the aim of this paper is to examine the relationship between…

  10. Task Goal Attributes, n Achievement, and Supervisory Performance. Technical Report No. 30.

    ERIC Educational Resources Information Center

    Steers, Richard M.

    A review of the research literature on goal-setting in organizational settings reveals that goal-setting on an individual job results in better task performance. However, the processes behind their effectiveness is unclear. For example, how are various job attributes of task goals related to performance, and how do various individual differences…

  11. The Effect of Performance Pay in Little Rock, Arkansas on Student Achievement. Research Brief

    ERIC Educational Resources Information Center

    Winters, Marcus; Greene, Jay; Ritter, Gary; Marsh, Ryan

    2008-01-01

    This paper examines evidence from a performance-pay program implemented in five Little Rock, Arkansas elementary schools between 2004 and 2007. Using a differences-in-differences approach, the evidence shows that students whose teachers were eligible for performance pay made substantially larger test score gains in math, reading, and language than…

  12. Sectionalizing interconnected transmission network to improve system performance and achieve fault current reduction

    SciTech Connect

    Ray, B.

    1998-12-31

    An analysis was recently undertaken at Northern States Power Company (NSP) in an attempt to identify the advantages and disadvantages of sectionalizing Twin Cities metropolitan area transmission system. Five specific sectionalization schemes were developed to evaluate the transmission system performance associated with each scenario. These schemes were judged against the following performance characteristics: fault current level, severity of voltage depression during faults, NSP system losses, system through flow and contingency operation. Study results indicated that by careful application of the splitting scheme, sectionalization can provide significant performance improvements and still have economic feasibility. A comparison between sectionalization costs (increased system losses) and its benefits (improved performance) would help determine to what degree sectionalization is economically feasible and make the final decision. Of the five schemes tested, the contour that appeared the best in terms of reliability, performance and economics was chosen for implementation in NSP system during 1997 summer.

  13. High-Performance and Omnidirectional Thin-Film Amorphous Silicon Solar Cell Modules Achieved by 3D Geometry Design.

    PubMed

    Yu, Dongliang; Yin, Min; Lu, Linfeng; Zhang, Hanzhong; Chen, Xiaoyuan; Zhu, Xufei; Che, Jianfei; Li, Dongdong

    2015-11-01

    High-performance thin-film hydrogenated amorphous silicon solar cells are achieved by combining macroscale 3D tubular substrates and nanoscaled 3D cone-like antireflective films. The tubular geometry delivers a series of advantages for large-scale deployment of photovoltaics, such as omnidirectional performance, easier encapsulation, decreased wind resistance, and easy integration with a second device inside the glass tube. PMID:26418573

  14. Relationships of Cognitive and Metacognitive Learning Strategies to Mathematics Achievement in Four High-Performing East Asian Education Systems

    ERIC Educational Resources Information Center

    Areepattamannil, Shaljan; Caleon, Imelda S.

    2013-01-01

    The authors examined the relationships of cognitive (i.e., memorization and elaboration) and metacognitive learning strategies (i.e., control strategies) to mathematics achievement among 15-year-old students in 4 high-performing East Asian education systems: Shanghai-China, Hong Kong-China, Korea, and Singapore. In all 4 East Asian education…

  15. Gamed by the System: Adequate Yearly Progress as an Indicator of Persistently Low-Achieving School Performance

    ERIC Educational Resources Information Center

    Hochbein, Craig; Mitchell, Amanda M.; Pollio, Martin

    2013-01-01

    The recent policy focus on the turnaround of persistently low-achieving schools has generated considerable debate about the reforms needed to dramatically and quickly increase school performance. The purpose of this article is not to focus on specific turnaround interventions, but rather on the identification of schools slated to receive these…

  16. Pilot Study: EatFit Impacts Sixth Graders' Academic Performance on Achievement of Mathematics and English Education Standards

    ERIC Educational Resources Information Center

    Shilts, Mical Kay; Lamp, Cathi; Horowitz, Marcel; Townsend, Marilyn S.

    2009-01-01

    Objective: Investigate the impact of a nutrition education program on student academic performance as measured by achievement of education standards. Design: Quasi-experimental crossover-controlled study. Setting: California Central Valley suburban elementary school (58% qualified for free or reduced-priced lunch). Participants: All sixth-grade…

  17. The Relationship of Selected Measures of Proprioception to Physical Growth, Motor Performance, and Academic Achievement in Young Children.

    ERIC Educational Resources Information Center

    Haubenstricker, John L.; Milne, D. Conrad

    This study investigates the relationship of selected measures of proprioception to measures of physical growth, motor performance, and academic achievement in young children. Measures were obtained from 321 boys and girls attending kindergarten and first and second grade. Sample correlation matrices were computed on all variables at each grade…

  18. Associative Verbal Encoding (a/v/e): A Measure of Language Performance and Its Relationship to Reading Achievement.

    ERIC Educational Resources Information Center

    Mickelson, Norma I.

    This study examined the assumption that language expression and reading performance are related processes. Subjects included a total of 676 nine-year-old children of heterogeneous socioeconomic status, intelligence, and achievement levels. Verbal fluency was defined as being a measure of associative verbal encoding (a/v/e), wherein children give…

  19. Children's Achievement Expectations and Performance as a Function of Two Consecutive Reinforcement Experiences, Sex of Subject, and Sex of Experimenter

    ERIC Educational Resources Information Center

    Montanelli, Dale Soderman; Hill, Kennedy T.

    1969-01-01

    Presents research patterned on two earlier studies by the Crandalls 1963, 1964 on the effects of praise, criticism, and nonreaction on 10-year-old children involved in a marble-dropping task. The subjects tended to increase in performance and decrease in achievement expectancy when criticized. Table, graphs, and bibliography. (RW)

  20. Instructional Resources as Determinants of English Language Performance of Secondary School High-Achieving Students in Ibadan, Oyo State

    ERIC Educational Resources Information Center

    Adelodun, Gboyega Adelowo; Asiru, Abdulahi Babatunde

    2015-01-01

    This study examined the role played by instructional resources in enhancing performance of students, especially that of high-achievers, in English Language. The study is descriptive in nature and it adopted a survey design. Simple random sampling technique was used for the selection of fifty (50) SSI-SSIII students from five schools in Ibadan…

  1. An Investigation of World Language Teachers' Use of Student Performance Data to Inform Teaching and to Help Improve Student Achievement

    ERIC Educational Resources Information Center

    Koffi, Bruno N.

    2013-01-01

    This qualitative study investigated the types of content-based student performance data World Language teachers used to improve instruction and student academic achievement, the purposes for which they used data, the issues they encountered, and the suggestions they made for more effective use of data. The Standards for Foreign Language Learning…

  2. The Role of Moral and Performance Character Strengths in Predicting Achievement and Conduct among Urban Middle School Students

    ERIC Educational Resources Information Center

    Seider, Scott; Gilbert, Jennifer K.; Novick, Sarah; Gomez, Jessica

    2013-01-01

    Background/Context: Performance character consists of the qualities that allow individuals to regulate their thoughts and actions in ways that support achievement in a particular endeavor. Moral character consists of the qualities relevant to striving for ethical behavior in one's relationships with other individuals and communities. A…

  3. Conscientiousness, Achievement Striving, and Intelligence as Performance Predictors in a Sample of German Psychology Students: Always a Linear Relationship?

    ERIC Educational Resources Information Center

    Ziegler, Matthias; Knogler, Maximilian; Buhner, Markus

    2009-01-01

    Studies on the interface between cognitive ability (intelligence) and personality in the prediction of academic performance have yielded mixed results so far. Especially an interaction between conscientiousness (and its facet achievement striving) and intelligence has been investigated. The hypothesis is that conscientiousness enhances the impact…

  4. Judgments of Self-Perceived Academic Competence and Their Differential Impact on Students' Achievement Motivation, Learning Approach, and Academic Performance

    ERIC Educational Resources Information Center

    Ferla, Johan; Valcke, Martin; Schuyten, Gilberte

    2010-01-01

    Using path analysis, the present study focuses on the development of a model describing the impact of four judgments of self-perceived academic competence on higher education students' achievement goals, learning approach, and academic performance. Results demonstrate that academic self-efficacy, self-efficacy for self-regulated learning, academic…

  5. Patterns and Predictors of Adolescent Academic Achievement and Performance in a Sample of Children with Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Langberg, Joshua M.; Molina, Brooke S. G.; Arnold, L. Eugene; Epstein, Jeffery N.; Altaye, Mekibib; Hinshaw, Stephen P.; Swanson, James M.; Wigal, Timothy; Hechtman, Lily

    2011-01-01

    The current study examined predictors of academic achievement, measured by standardized test scores, and performance, measured by school grades, in adolescents (Mn = 16.8) who met diagnostic criteria for Attention-Deficit/Hyperactivity Disorder (ADHD)-Combined type in early childhood (Mn age = 8.5; N = 579). Several mediation models were also…

  6. A University Engagement Model for Achieving Technology Adoption and Performance Improvement Impacts in Healthcare, Manufacturing, and Government

    ERIC Educational Resources Information Center

    McKinnis, David R.; Sloan, Mary Anne; Snow, L. David; Garimella, Suresh V.

    2014-01-01

    The Purdue Technical Assistance Program (TAP) offers a model of university engagement and service that is achieving technology adoption and performance improvement impacts in healthcare, manufacturing, government, and other sectors. The TAP model focuses on understanding and meeting the changing and challenging needs of those served, always…

  7. Prior Mathematics Achievement, Cognitive Appraisals and Anxiety as Predictors of Finnish Students' Later Mathematics Performance and Career Orientation

    ERIC Educational Resources Information Center

    Kyttala, Minna; Bjorn, Piia Maria

    2010-01-01

    The aim of this two-year longitudinal study was to investigate the role and impact of prior mathematics performance, cognitive appraisals and mathematics-specific, affective anxiety in determining later mathematics achievement and future career orientation among Finnish adolescents. The basic ideas of the control-value theory, assumed to be…

  8. Why IEP Teams Assign Low Performers with Mild Disabilities to the Alternate Assessment Based on Alternate Achievement Standards

    ERIC Educational Resources Information Center

    Cho, Hyun-Jeong; Kingston, Neal

    2013-01-01

    The purpose of this case study was to determine teachers' rationales for assigning students with mild disabilities to alternate assessment based on alternate achievement standards (AA-AAS). In interviews, special educators stated that their primary considerations in making the assignments were low academic performance, student use of extended…

  9. Participation and Performance Reporting for the Alternate Assessment Based on Modified Achievement Standards (AA-MAS). Technical Report 58

    ERIC Educational Resources Information Center

    Albus, Deb; Thurlow, Martha L.; Lazarus, Sheryl S.

    2011-01-01

    This report examines publicly reported participation and performance data for the alternate assessment based on modified achievement standards (AA-MAS). The authors' analysis of these data included all states publicly reporting AA-MAS data, regardless of whether they had received approval to use the results for Title I accountability calculations.…

  10. Performance in Solving Arithmetic Problems: A Comparison of Children with Different Levels of Achievement in Mathematics and Reading

    ERIC Educational Resources Information Center

    Reikeras, Elin K. L.

    2006-01-01

    The aim of the present study was to investigate the performance in arithmetic related to achievement levels in reading and mathematics. Basic arithmetical facts and multi-step calculations were examined. The participants were 941 pupils aged 8 (N = 415), 10 (N = 274) and 13 (N = 252) years. The pupils were divided into four groups by standardized…

  11. Relationships between Learning Styles and Academic Achievement and Brain Hemispheric Dominance and Academic Performance in Business and Accounting Courses.

    ERIC Educational Resources Information Center

    Carthey, Joseph H.

    A study determined if relationships exist between learning styles and academic achievement and brain hemispheric dominance and academic performance in the courses of principles of management, business law, intermediate accounting, and principles of economics. All second-year accounting students (64 students) at Northeast Iowa Community College…

  12. Assessing Medicare's hospital pay-for-performance programs and whether they are achieving their goals.

    PubMed

    Kahn, Charles N; Ault, Thomas; Potetz, Lisa; Walke, Thomas; Chambers, Jayne Hart; Burch, Samantha

    2015-08-01

    Three separate pay-for-performance programs affect the amount of Medicare payment for inpatient services to about 3,400 US hospitals. These payments are based on hospital performance on specified measures of quality of care. A growing share of Medicare hospital payments (6 percent by 2017) are dependent upon how hospitals perform under the Hospital Readmissions Reduction Program, the Value-Based Purchasing Program, and the Hospital-Acquired Condition Reduction Program. In 2015 four of five hospitals subject to these programs will be penalized under one or more of them, and more than one in three major teaching hospitals will be penalized under all three. Interactions among these programs should be considered going forward, including overlap among measures and differences in scoring performance. PMID:26240240

  13. Design and performance of tapered cubic anvil used for achieving higher pressure and larger sample cell.

    PubMed

    Han, Qi-Gang; Yang, Wen-Ke; Zhu, Pin-Wen; Ban, Qing-Chu; Yan, Ni; Zhang, Qiang

    2013-07-01

    In order to increase the maximum cell pressure of the cubic high pressure apparatus, we have developed a new structure of tungsten carbide cubic anvil (tapered cubic anvil), based on the principle of massive support and lateral support. Our results indicated that the tapered cubic anvil has some advantages. First, tapered cubic anvil can push the transfer rate of pressure well into the range above 36.37% compare to the conventional anvil. Second, the rate of failure crack decreases about 11.20% after the modification of the conventional anvil. Third, the limit of static high-pressure in the sample cell can be extended to 13 GPa, which can increase the maximum cell pressure about 73.3% than that of the conventional anvil. Fourth, the volume of sample cell compressed by tapered cubic anvils can be achieved to 14.13 mm(3) (3 mm diameter × 2 mm long), which is three and six orders of magnitude larger than that of double-stage apparatus and diamond anvil cell, respectively. This work represents a relatively simple method for achieving higher pressures and larger sample cell. PMID:23902079

  14. Striving for Excellence Sometimes Hinders High Achievers: Performance-Approach Goals Deplete Arithmetical Performance in Students with High Working Memory Capacity.

    PubMed

    Crouzevialle, Marie; Smeding, Annique; Butera, Fabrizio

    2015-01-01

    We tested whether the goal to attain normative superiority over other students, referred to as performance-approach goals, is particularly distractive for high-Working Memory Capacity (WMC) students-that is, those who are used to being high achievers. Indeed, WMC is positively related to high-order cognitive performance and academic success, a record of success that confers benefits on high-WMC as compared to low-WMC students. We tested whether such benefits may turn out to be a burden under performance-approach goal pursuit. Indeed, for high achievers, aiming to rise above others may represent an opportunity to reaffirm their positive status-a stake susceptible to trigger disruptive outcome concerns that interfere with task processing. Results revealed that with performance-approach goals-as compared to goals with no emphasis on social comparison-the higher the students' WMC, the lower their performance at a complex arithmetic task (Experiment 1). Crucially, this pattern appeared to be driven by uncertainty regarding the chances to outclass others (Experiment 2). Moreover, an accessibility measure suggested the mediational role played by status-related concerns in the observed disruption of performance. We discuss why high-stake situations can paradoxically lead high-achievers to sub-optimally perform when high-order cognitive performance is at play. PMID:26407097

  15. Striving for Excellence Sometimes Hinders High Achievers: Performance-Approach Goals Deplete Arithmetical Performance in Students with High Working Memory Capacity

    PubMed Central

    Crouzevialle, Marie; Smeding, Annique; Butera, Fabrizio

    2015-01-01

    We tested whether the goal to attain normative superiority over other students, referred to as performance-approach goals, is particularly distractive for high-Working Memory Capacity (WMC) students—that is, those who are used to being high achievers. Indeed, WMC is positively related to high-order cognitive performance and academic success, a record of success that confers benefits on high-WMC as compared to low-WMC students. We tested whether such benefits may turn out to be a burden under performance-approach goal pursuit. Indeed, for high achievers, aiming to rise above others may represent an opportunity to reaffirm their positive status—a stake susceptible to trigger disruptive outcome concerns that interfere with task processing. Results revealed that with performance-approach goals—as compared to goals with no emphasis on social comparison—the higher the students’ WMC, the lower their performance at a complex arithmetic task (Experiment 1). Crucially, this pattern appeared to be driven by uncertainty regarding the chances to outclass others (Experiment 2). Moreover, an accessibility measure suggested the mediational role played by status-related concerns in the observed disruption of performance. We discuss why high-stake situations can paradoxically lead high-achievers to sub-optimally perform when high-order cognitive performance is at play. PMID:26407097

  16. Multi-Scale Effects of Nestling Diet on Breeding Performance in a Terrestrial Top Predator Inferred from Stable Isotope Analysis

    PubMed Central

    Resano-Mayor, Jaime; Hernández-Matías, Antonio; Real, Joan; Moleón, Marcos; Parés, Francesc; Inger, Richard; Bearhop, Stuart

    2014-01-01

    Inter-individual diet variation within populations is likely to have important ecological and evolutionary implications. The diet-fitness relationships at the individual level and the emerging population processes are, however, poorly understood for most avian predators inhabiting complex terrestrial ecosystems. In this study, we use an isotopic approach to assess the trophic ecology of nestlings in a long-lived raptor, the Bonelli’s eagle Aquila fasciata, and investigate whether nestling dietary breath and main prey consumption can affect the species’ reproductive performance at two spatial scales: territories within populations and populations over a large geographic area. At the territory level, those breeding pairs whose nestlings consumed similar diets to the overall population (i.e. moderate consumption of preferred prey, but complemented by alternative prey categories) or those disproportionally consuming preferred prey were more likely to fledge two chicks. An increase in the diet diversity, however, related negatively with productivity. The age and replacements of breeding pair members had also an influence on productivity, with more fledglings associated to adult pairs with few replacements, as expected in long-lived species. At the population level, mean productivity was higher in those population-years with lower dietary breadth and higher diet similarity among territories, which was related to an overall higher consumption of preferred prey. Thus, we revealed a correspondence in diet-fitness relationships at two spatial scales: territories and populations. We suggest that stable isotope analyses may be a powerful tool to monitor the diet of terrestrial avian predators on large spatio-temporal scales, which could serve to detect potential changes in the availability of those prey on which predators depend for breeding. We encourage ecologists and evolutionary and conservation biologists concerned with the multi-scale fitness consequences of inter

  17. Analysis of cytochrome P450 metabolites of arachidonic acid by stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry.

    PubMed

    Zhu, Quan-Fei; Hao, Yan-Hong; Liu, Ming-Zhou; Yue, Jiang; Ni, Jian; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-09-01

    Cytochrome P450 metabolites of arachidonic acid (AA) belong to eicosanoids and are potent lipid mediators of inflammation. It is well-known that eicosanoids play an important role in numerous pathophysiological processes. Therefore, quantitative analysis of cytochrome P450 metabolites of AA, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatreinoic acids (EETs), and dihydroxyeicosatrienoic acids (DHETs) can provide crucial information to uncover underlying mechanisms of cytochrome P450 metabolites of AA related diseases. Herein, we developed a highly sensitive method to identify and quantify HETEs, EETs, and DHETs in lipid extracts of biological samples based on stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry. To this end, a pair of stable isotope probes, 2-dimethylaminoethylamine (DMED) and d4-2-dimethylaminoethylamine (d4-DMED), were utilized to facilely label eicosanoids. The heavy labeled eicosanoid standards were prepared and used as internal standards for quantification to minimize the matrix and ion suppression effects in mass spectrometry analysis. In addition, the detection sensitivities of DMED labeled eicosanoids improved by 3-104 folds in standard solution and 5-138 folds in serum matrix compared with unlabeled analytes. Moreover, a good separation of eicosanoids isomers was achieved upon DMED labeling. The established method provided substantial sensitivity (limit of quantification at sub-picogram), high specificity, and broad linear dynamics range (3 orders of magnitude). We further quantified cytochrome P450 metabolites of AA in rat liver, heart, brain tissues and human serum using the developed method. The results showed that 19 eicosanoids could be distinctly detected and the contents of 11-, 15-, 16-, 20-HETE, 5,6-EET, and 14,15-EET in type 2 diabetes mellitus patients and 5-, 11-, 12-, 15-, 16-, 20-HETE, 8,9-EET, and 5,6-DHET in myeloid leukemia patients had significant changes

  18. Cost/Performance Ratio Achieved by Using a Commodity-Based Cluster

    NASA Technical Reports Server (NTRS)

    Lopez, Isaac

    2001-01-01

    Researchers at the NASA Glenn Research Center acquired a commodity cluster based on Intel Corporation processors to compare its performance with a traditional UNIX cluster in the execution of aeropropulsion applications. Since the cost differential of the clusters was significant, a cost/performance ratio was calculated. After executing a propulsion application on both clusters, the researchers demonstrated a 9.4 cost/performance ratio in favor of the Intel-based cluster. These researchers utilize the Aeroshark cluster as one of the primary testbeds for developing NPSS parallel application codes and system software. The Aero-shark cluster provides 64 Intel Pentium II 400-MHz processors, housed in 32 nodes. Recently, APNASA - a code developed by a Government/industry team for the design and analysis of turbomachinery systems was used for a simulation on Glenn's Aeroshark cluster.

  19. Modified surface loading process for achieving improved performance of the quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Jin, Zhongxiu; Zhu, Jun; Xu, Yafeng; Zhou, Li; Dai, Songyuan

    2016-06-01

    Achieving high surface coverage of the colloidal quantum dots (QDs) on TiO2 films has been challenging for quantum dot-sensitized solar cells (QDSCs). Herein, a general surface engineering approach was proposed to increase the loading of these QDs. It was found that S2- treatment/QD re-uptake process can significantly improve the attachment of the QDs on TiO2 films. Surface concentration of the QDs was improved by ∼60%, which in turn greatly enhances light absorption and decreases carrier recombination in QDSCs. Ensuing QDSCs with optimized QD loading exhibit a power conversion efficiency of 3.66%, 83% higher than those fabricated with standard procedures.

  20. Electrodeposited Structurally Stable V2O5 Inverse Opal Networks as High Performance Thin Film Lithium Batteries.

    PubMed

    Armstrong, Eileen; McNulty, David; Geaney, Hugh; O'Dwyer, Colm

    2015-12-01

    High performance thin film lithium batteries using structurally stable electrodeposited V2O5 inverse opal (IO) networks as cathodes provide high capacity and outstanding cycling capability and also were demonstrated on transparent conducting oxide current collectors. The superior electrochemical performance of the inverse opal structures was evaluated through galvanostatic and potentiodynamic cycling, and the IO thin film battery offers increased capacity retention compared to micron-scale bulk particles from improved mechanical stability and electrical contact to stainless steel or transparent conducting current collectors from bottom-up electrodeposition growth. Li(+) is inserted into planar and IO structures at different potentials, and correlated to a preferential exposure of insertion sites of the IO network to the electrolyte. Additionally, potentiodynamic testing quantified the portion of the capacity stored as surface bound capacitive charge. Raman scattering and XRD characterization showed how the IO allows swelling into the pore volume rather than away from the current collector. V2O5 IO coin cells offer high initial capacities, but capacity fading can occur with limited electrolyte. Finally, we demonstrate that a V2O5 IO thin film battery prepared on a transparent conducting current collector with excess electrolyte exhibits high capacities (∼200 mAh g(-1)) and outstanding capacity retention and rate capability. PMID:26571342

  1. Initial Teacher Education: Does Self-Efficacy Influence Candidate Teacher Academic Achievement and Future Career Performance?

    ERIC Educational Resources Information Center

    Shawer, Saad F.

    2013-01-01

    This quantitative investigation examined the influence of low and high self-efficacy on candidate teacher academic performance in a foreign language teaching methodology course through testing the speculation that high self-efficacy levels would improve pedagogical-content knowledge (PCK). Positivism guided the research design at the levels of…

  2. Mayoral Governance and Student Achievement: How Mayor-Led Districts Are Improving School and Student Performance

    ERIC Educational Resources Information Center

    Wong, Kenneth K.; Shen, Francis X.

    2013-01-01

    Mayoral control and accountability is one of very few major education reforms that aim at governance coherence in this nation's highly fragmented urban school systems. A primary feature of mayoral governance is that it holds the office of the mayor accountable for school performance. As an institutional redesign, mayoral governance integrates…

  3. Aural Dictation Affects High Achievement in Sight Singing, Performance and Composition Skills

    ERIC Educational Resources Information Center

    Rogers, Melissa

    2013-01-01

    The nature of skill acquisition has long been of interest to music educators. This study considers the research context for relationships between aural dictation, sight singing, performance and composition skills. Then, relationships between these skill areas are quantitatively investigated using data from the Australian New South Wales Music 2…

  4. "High" Achievers? Cannabis Access and Student Performance. CEP Discussion Paper No. 1340

    ERIC Educational Resources Information Center

    Marie, Olivier; Zölitz, Ulf

    2015-01-01

    This paper investigates how legal cannabis access affects student performance. Identification comes from an exceptional policy introduced in the city of Maastricht which discriminated legal access based on individuals' nationality. We apply a difference-in-difference approach using administrative panel data on over 54,000 course grades of local…

  5. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  6. Teacher Performance Pay Signals and Student Achievement: Are Signals Accurate, and How well Do They Work?

    ERIC Educational Resources Information Center

    Manzeske, David; Garland, Marshall; Williams, Ryan; West, Benjamin; Kistner, Alexandra Manzella; Rapaport, Amie

    2016-01-01

    High-performing teachers tend to seek out positions at more affluent or academically challenging schools, which tend to hire more experienced, effective educators. Consequently, low-income and minority students are more likely to attend schools with less experienced and less effective educators (see, for example, DeMonte & Hanna, 2014; Office…

  7. The Mental Aspect of Athletics: The Effects of the Mind's Influence on Athletic Achievement and Performance.

    ERIC Educational Resources Information Center

    McCollough, David D.

    This study of athletes seeks to determine that a relationship exists between the mind and the body. It presents negative psychological factors that may arise and shows possible ways to enhance athletic performance through psychological techniques. The central part of the study is an annotated bibliography covering selected literature on these…

  8. Effects of Audio- and Videotape Models on Performance Achievement of Beginning Clarinetists.

    ERIC Educational Resources Information Center

    Linklater, Fraser

    1997-01-01

    Investigates the effects on home practice of three different types of cassette tapes (a videotape, a modeling audiotape, and a nonmodeling audiotape) on the performance of beginning clarinet students. Finds no significant impact on amount of weekly practice, of practice using tapes, or of parental help based on tape type. (DSK)

  9. Comparing the performance of English mental health providers in achieving patient outcomes.

    PubMed

    Moran, Valerie; Jacobs, Rowena

    2015-09-01

    Evidence on provider payment systems that incorporate patient outcomes is limited for mental health care. In England, funding for mental health care services is changing to a prospective payment system with a future objective of linking some part of provider payment to outcomes. This research examines performance of mental health providers offering hospital and community services, in order to investigate if some are delivering better outcomes. Outcomes are measured using the Health of the Nation Outcome Scales (HoNOS) - a clinician-rated routine outcome measure (CROM) mandated for national use. We use data from the Mental Health Minimum Data Set (MHMDS) - a dataset on specialist mental health care with national coverage - for the years 2011/12 and 2012/13 with a final estimation sample of 305,960 observations with follow-up HoNOS scores. A hierarchical ordered probit model is used and outcomes are risk adjusted with independent variables reflecting demographic, need, severity and social indicators. A hierarchical linear model is also estimated with the follow-up total HoNOS score as the dependent variable and the baseline total HoNOS score included as a risk-adjuster. Provider performance is captured by a random effect that is quantified using Empirical Bayes methods. We find that worse outcomes are associated with severity and better outcomes with older age and social support. After adjusting outcomes for various risk factors, variations in performance are still evident across providers. This suggests that if the intention to link some element of provider payment to outcomes becomes a reality, some providers may gain financially whilst others may lose. The paper contributes to the limited literature on risk adjustment of outcomes and performance assessment of providers in mental health in the context of prospective activity-based payment systems. PMID:26218853

  10. Achieving supercomputer performance for neural net simulation with an array of digital signal processors

    SciTech Connect

    Muller, U.A.; Baumle, B.; Kohler, P.; Gunzinger, A.; Guggenbuhl, W.

    1992-10-01

    Music, a DSP-based system with a parallel distributed-memory architecture, provides enormous computing power yet retains the flexibility of a general-purpose computer. Reaching a peak performance of 2.7 Gflops at a significantly lower cost, power consumption, and space requirement than conventional supercomputers, Music is well suited to computationally intensive applications such as neural network simulation. 12 refs., 9 figs., 2 tabs.

  11. Athlete Atypicity on the Edge of Human Achievement: Performances Stagnate after the Last Peak, in 1988

    PubMed Central

    Berthelot, Geoffroy; Tafflet, Muriel; El Helou, Nour; Len, Stéphane; Escolano, Sylvie; Guillaume, Marion; Nassif, Hala; Tolaïni, Julien; Thibault, Valérie; Desgorces, François Denis; Hermine, Olivier; Toussaint, Jean-François

    2010-01-01

    The growth law for the development of top athletes performances remains unknown in quantifiable sport events. Here we present a growth model for 41351 best performers from 70 track and field (T&F) and swimming events and detail their characteristics over the modern Olympic era. We show that 64% of T&F events no longer improved since 1993, while 47% of swimming events stagnated after 1990, prior to a second progression step starting in 2000. Since then, 100% of swimming events continued to progress. We also provide a measurement of the atypicity for the 3919 best performances (BP) of each year in every event. The secular evolution of this parameter for T&F reveals four peaks; the most recent (1988) followed by a major stagnation. This last peak may correspond to the most recent successful attempt to push forward human physiological limits. No atypicity trend is detected in swimming. The upcoming rarefaction of new records in sport may be delayed by technological innovations, themselves depending upon economical constraints. PMID:20098706

  12. Tailoring the structure of thin film nanocomposite membranes to achieve seawater RO membrane performance.

    PubMed

    Lind, Mary Laura; Eumine Suk, Daniel; Nguyen, The-Vinh; Hoek, Eric M V

    2010-11-01

    Herein we report on the formation and characterization of pure polyamide thin film composite (TFC) and zeolite-polyamide thin film nanocomposite (TFN) reverse osmosis (RO) membranes. Four different physical-chemical post-treatment combinations were applied after the interfacial polymerization reaction to change the molecular structure of polyamide and zeolite-polyamide thin films. Both TFC and TFN hand-cast membranes were more permeable, hydrophilic, and rough than a commercial seawater RO membrane. Salt rejection by TFN membranes was consistently below that of hand-cast TFC membranes; however, two TFN membranes exhibited 32 g/L NaCl rejections above 99.4%, which was better than the commercial membrane under the test conditions employed. The nearly defect-free TFN films that produced such high rejections were achieved only with wet curing, regardless of other post-treatments. Polyamide films formed in the presence of zeolite nanoparticles were less cross-linked than similarly cast pure polyamide films. At the very low nanoparticle loadings evaluated, differences between pure polyamide and zeolite-polyamide membrane water and salt permeability correlated weakly with extent of cross-linking of the polyamide film, which suggests that defects and molecular-sieving largely govern transport through zeolite-polyamide thin film nanocomposite membranes. PMID:20942398

  13. Achieving superior MEBES performance through the use of SPC programs and state-of-the-art facilities

    NASA Astrophysics Data System (ADS)

    Braz, Linda A.

    1993-06-01

    A MEBES III system can perform at levels that far exceed those published by the manufacturer. To achieve this, the photomask facility must be capable of maintaining extremely tight temperature controls. In addition, noise free power must be utilized and Class 10 cleanliness maintained. Through the use of a statistical process control (SPC) program generated at Etec, the MEBES performance can be monitored. Anomalies in system performance can be immediately identified and corrected without losing production masks. Impending system problems such as needed gun changes, gun centering, aperture changes, and charging of plates can be recognized and corrected before MEBES system performance would exceed our specifications. This paper also describes some of the unique facility designs/controls and demonstrated, through results, how these contribute to the MEBES performance.

  14. The effect of uniform feeding on boiler performance and equipment development to achieve this objective with low-cost, hard-to-handle coals

    SciTech Connect

    Black, R.L.; Saunders, T.W.

    1995-03-01

    A two-year test program, sponsored by the Electric Power Research Institute (EPRI), addressed handling problems with low-cost anthracite silt at the Pennsylvania Power & Light Sunbury Steam Electric Station and monitored development of the Stamet Solids Pump System, a unique equipment for accurate feeding of difficult handling coal. With the first objective successfully achieved, the test program additionally studied the effect of u uniform feeding on boiler performance. EPRI concluded that the Stamet Solids Pump System: eliminates the severe handling problems associated with the feeding of hard-to-handle materials and provides continuous, accurately metered delivery of coal feed without operator intervention; provides stable operating conditions that allow plant personnel to control boiler performance; improves power plant safety by drastically reducing pluggages and associated work in feeders. The EPRI test program confirmed significant improvements in boiler performance and stabilized ancillary equipment variables, arising from the continuous, accurate matching of coal to demand. Reduced boiler swings also resulted in improved environmental emissions control.

  15. Achieving Equivalent Academic Performance Between Campuses Using a Distributed Education Model

    PubMed Central

    McCall, Kenneth L.; Raehl, Cynthia L.; Smith, Quentin R.; Lockman, Paul R.

    2009-01-01

    Objectives To demonstrate that students in competency-based anatomy and pharmaceutical calculations courses performed similarly whether enrolled in the classes through distance education or face-to-face lectures. Methods Student outcomes data including module examination scores, final course grades, and student demographics data were collected, merged, and analyzed. Results Mean module examination final scores and final course grades did not significantly differ between students at the lecture site and students at the remote site. Conclusions The competency-based anatomy and pharmaceutical calculations courses, whether remote or at the lecture site, provided equitable learning opportunities and roughly equivalent learning outcomes for students. PMID:19777103

  16. Uncooled amorphous-silicon technology: high-performance achievement and future trends

    NASA Astrophysics Data System (ADS)

    Mottin, Eric; Bain, Astrid; Martin, Jean-Luc; Ouvrier-Buffet, Jean-Louis; Yon, Jean-Jacques; Chatard, Jean-Pierre; Tissot, Jean-Luc

    2002-08-01

    The emergence of uncooled infrared detectors has opened new opportunities for IR imaging both for military and civil applications. Infrared imaging sensors that operate without cryogenic cooling have the potential to provide the military or civilian users with infrared vision capabilities packaged in a camera of extremely small size, weight and power. Uncooled infrared sensor technology has advanced rapidly in the past few years. Higher performance sensors, electronics integration at the sensor, and new concepts for signal processing are generating advanced infrared focal plane arrays. This would significantly reduce the cost and accelerate the implementation of sensors for applications such as surveillance or predictive maintenance. We present the uncooled infrared detector operation principle and the development at CEA/LETI from the 256 x 64 with a pitch of 50 micrometers to the 320 x 240 with a pitch of 35 micrometers . LETI has been involved in Amorphous Silicon uncooled microbolometer development since 1992. This silicon IR detection is now well mastered and matured so that industrial transfer of LETI technology was performed in 2000 towards Sofradir. Industrial production of 320 x 240 microbolometer array with 45micrometers pitch is then started., we present the readout circuit architectures designs and its evolution from the 256 x 64 array to the different version of 320 x 240 arrays. Electro-optical results obtained from these IRCMOS are presented. NEDT close to 30 mK is now obtained with our standard microbolometer amorphous silicon technology.

  17. Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

    PubMed

    Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

    2016-02-01

    A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively. PMID:26820247

  18. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone

    NASA Astrophysics Data System (ADS)

    Luo, Wenhao; Sankar, Meenakshisundaram; Beale, Andrew M.; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-03-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on titanium dioxide are prepared with a modified metal impregnation method. Gold-palladium/titanium dioxide shows a marked,~27-fold increase in activity (that is, turnover frequency of 0.1 s-1) compared with its monometallic counterparts. Although ruthenium-palladium/titanium dioxide is not only exceptionally active (that is, turnover frequency of 0.6 s-1), it shows excellent, sustained selectivity to γ-valerolactone (99%). The dilution and isolation of ruthenium by palladium is thought to be responsible for this superior catalytic performance. Alloying, furthermore, greatly improves the stability of both supported nano-alloy catalysts.

  19. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone

    PubMed Central

    Luo, Wenhao; Sankar, Meenakshisundaram; Beale, Andrew M.; He, Qian; Kiely, Christopher J.; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on titanium dioxide are prepared with a modified metal impregnation method. Gold-palladium/titanium dioxide shows a marked,~27-fold increase in activity (that is, turnover frequency of 0.1 s−1) compared with its monometallic counterparts. Although ruthenium-palladium/titanium dioxide is not only exceptionally active (that is, turnover frequency of 0.6 s−1), it shows excellent, sustained selectivity to γ-valerolactone (99%). The dilution and isolation of ruthenium by palladium is thought to be responsible for this superior catalytic performance. Alloying, furthermore, greatly improves the stability of both supported nano-alloy catalysts. PMID:25779385

  20. The effects of lidoflazine on exercise performance and thallium stress scintigraphy in patients with stable angina pectoris

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1982-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a 7-month study, 36 patients with stable angina pectoris were tested during a 3-month single-blind placebo phase. Nineteen were then randomized by double-blind methods to lidoflazine and 17 to placebo therapy. The lidoflazine group had a significant (p < 0.01) reduction in anginal attacks; the placebo group did not. Exercise testing demonstrated that lidoflazine therapy was associated with a 34% increase in total work performance and a 15.6% increase in peak calculated oxygen uptake during double-blind treatment (both p < 0.004 compared with the placebo group). Heart rate was significantly reduced at submaximal levels of exercise during lidoflazine therapy (p < 0.04). Nitroglycerin consumption and electrocardiographic changes at the end of exercise did not change during the double-blind phase. In a second study of six similar patients, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  1. The effects of lidoflazine on exercise performance and thallium stress scintigraphy in patients with stable angina pectoris

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1982-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a 7-month study, 36 patients with stable angina pectoris were tested during a 3-month single-blind placebo phase. Nineteen were then randomized by double-blind methods to lidoflazine and 17 to placebo therapy. The lidoflazine group had a significant (p less than 0.01) reduction in anginal attacks; the placebo group did not. Exercise testing demonstrated that lidoflazine therapy was associated with a 34% increase in total work performance and a 15.6% increase in peak calculated oxygen uptake during double-blind treatment (both p less than 0.004 compared with the placebo group). Heart rate was significantly reduced at submaximal levels of exercise during lidoflazine therapy (p less than 0.04). Nitroglycerin consumption and electrocardiographic changes at the end of exercise did not change during the double-blind phase. In a second study of six similar patients, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  2. High performing and stable supported nano-alloys for the catalytic hydrogenation of levulinic acid to γ-valerolactone.

    PubMed

    Luo, Wenhao; Sankar, Meenakshisundaram; Beale, Andrew M; He, Qian; Kiely, Christopher J; Bruijnincx, Pieter C A; Weckhuysen, Bert M

    2015-01-01

    The catalytic hydrogenation of levulinic acid, a key platform molecule in many biorefinery schemes, into γ-valerolactone is considered as one of the pivotal reactions to convert lignocellulose-based biomass into renewable fuels and chemicals. Here we report on the development of highly active, selective and stable supported metal catalysts for this reaction and on the beneficial effects of metal nano-alloying. Bimetallic random alloys of gold-palladium and ruthenium-palladium supported on titanium dioxide are prepared with a modified metal impregnation method. Gold-palladium/titanium dioxide shows a marked,~27-fold increase in activity (that is, turnover frequency of 0.1 s(-1)) compared with its monometallic counterparts. Although ruthenium-palladium/titanium dioxide is not only exceptionally active (that is, turnover frequency of 0.6 s(-1)), it shows excellent, sustained selectivity to γ-valerolactone (99%). The dilution and isolation of ruthenium by palladium is thought to be responsible for this superior catalytic performance. Alloying, furthermore, greatly improves the stability of both supported nano-alloy catalysts. PMID:25779385

  3. The Rapid Transit System That Achieves Higher Performance with Lower Life-Cycle Costs

    NASA Astrophysics Data System (ADS)

    Sone, Satoru; Takagi, Ryo

    In the age of traction system made of inverter and ac traction motors, distributed traction system with pure electric brake of regenerative mode has been recognised very advantageous. This paper proposes a new system as the lowest life-cycle cost system for high performance rapid transit, a new architecture and optimum parameters of power feeding system, and a new running method of trains. In Japan, these components of this proposal, i.e. pure electric brake and various countermeasures of reducing loss of regeneration have been already popular but not as yet the new running method for better utilisation of the equipment and for lower life-cycle cost. One example of what are proposed in this paper will be made as Tsukuba Express, which is under construction as the most modern commuter railway in Greater Tokyo area.

  4. Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes

    NASA Astrophysics Data System (ADS)

    Dang, Binh H. Q.; MacElroy, Don; Dowling, Denis P.

    2013-06-01

    The photoactivity of carbon-incorporated titanium dioxide (TiO2) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO2 through the use of microwave plasma processing. The process involved thermally treating printed TiO2 nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV-vis, ellipsometry, and optical profilometry. It was found that the methane gas was dissociated in the microwave plasma into its carbon species, which were then deposited as a nm-thick layer onto the TiO2 coatings, most likely in the form of graphite. The photovoltaic performances of both the TiO2 and the carbon-incorporated TiO2 were assessed through J-V and IPCE measurements of the N719-sensitized solar cells using the titania as their photoanodes. Up to a 72% improvement in the maximum power density (Pd-max) was observed for the carbon-incorporated TiO2 samples as compared to the TiO2, onto which no carbon was added. This improvement was found to be mainly associated with an increase in the short-circuit current density (Jsc), but independent from the open-circuit voltage (Voc), the filter factor (FF), and the level of dye adsorption. Possible contributory factors to the improved performance of the carbon-incorporated TiO2 were the enhanced electron conductivity and electron lifetime, both of which were elucidated through electrochemical impedance spectroscopy (EIS). When the surface layer was examined using XPS, the optimal carbon content on the TiO2 coating surface was found to be 8.4%, beyond which there was a reduction in the DSSC efficiency.

  5. Hysteresis-free, stable and efficient perovskite solar cells achieved by vacuum-treated thermal annealing of CH3NH3PbI3

    NASA Astrophysics Data System (ADS)

    Xie, Fengxian; Zhang, Di; Choy, Wallace C. H.

    2015-09-01

    The lead halide-based perovskite solar cells have emerged as a promising candidate in photovoltaic applications. However, the precise control over the morphologiy of the perovskite films (minimizing pore formation) and enhanced stability and reproducibility of the devices remain challenging, even though both will be necessary for further advancements. Here we introduce vacuum-assisted thermal annealing as a means of controlling the composition and morphology of the CH3NH3PbI3 films formed from PbCl2 and CH3NH3I as precursors. We identify the critical role that the CH3NH3Cl generated as a byproduct during the pervoskite synthesis plays for the photovoltaic performance of the perovskite film. Removing this byproduct through vacuum-assisted thermal annealing we succeeded in producing pure, pore-free planar CH3NH3PbI3 films showing high conversion efficiency (PCE) reaching 14.5%). Removal of CH3NH3Cl strongly attenuate the photocurrent hysteresis.

  6. Mechanical robust BiSbTe alloys with superior thermoelectric performance: A case study of stable hierarchical nanostructured thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Su, Xianli; Zheng, Yun; Tang, Xinfeng; Uher, Ctirad; Tang's Group Team; Uher's Group Team

    2015-03-01

    Poor machinability and susceptibility to brittle fracture of commercial ingots often impose significant limitations on the manufacturing process and durability of thermoelectric devices. In this study, melt spinning combined with plasma activated sintering (MS-PAS) method is employed with commercial p-type zone-melted (ZM) ingots of Bi0.5Sb1.5Te3. This fast synthesis approach achieves hierarchical structures and in-situ nanoscale precipitates, resulting in the simultaneous improvement of thermoelectric performance and mechanical properties. Benefitting from a strong suppression of the lattice thermal conductivity, a peak ZT of 1.22 is achieved at 340 K in MS-PAS synthesized structures, representing about a 40% enhancement over that of ZM ingots. Moreover, MS-PAS specimens with hierarchical structures exhibit superior machinability and mechanical properties with an almost 30% enhancement in the fracture toughness, eightfold and a factor of six increase in the compressive and flexural strength respectively. We wish to acknowledge support from the National Basic Research Program of China (973 program) under Project 2013CB632502.

  7. Tuning interactions between zeolite and supported metal by physical-sputtering to achieve higher catalytic performances

    PubMed Central

    Li, Xin-Gang; Liu, Cheng; Sun, Jian; Xian, Hui; Tan, Yi-Sheng; Jiang, Zheng; Taguchi, Akira; Inoue, Mitsuhiro; Yoneyama, Yoshiharu; Abe, Takayuki; Tsubaki, Noritatsu

    2013-01-01

    To substitute for petroleum, Fischer-Tropsch synthesis (FTS) is an environmentally benign process to produce synthetic diesel (n-paraffin) from syngas. Industrially, the synthetic gasoline (iso-paraffin) can be produced with a FTS process followed by isomerization and hydrocracking processes over solid-acid catalysts. Herein, we demonstrate a cobalt nano-catalyst synthesized by physical-sputtering method that the metallic cobalt nano-particles homogeneously disperse on the H-ZSM5 zeolite support with weak Metal-Support Interactions (MSI). This catalyst performed the high gasoline-range iso-paraffin productivity through the combined FTS, isomerization and hydrocracking reactions. The weak MSI results in the easy reducibility of the cobalt nano-particles; the high cobalt dispersion accelerates n-paraffin diffusion to the neighboring acidic sites on the H-ZSM5 support for isomerization and hydrocracking. Both factors guarantee its high CO conversion and iso-paraffin selectivity. This physical-sputtering technique to synthesize the supported metallic nano-catalyst is a promising way to solve the critical problems caused by strong MSI for various processes. PMID:24085106

  8. Tuning interactions between zeolite and supported metal by physical-sputtering to achieve higher catalytic performances.

    PubMed

    Li, Xin-Gang; Liu, Cheng; Sun, Jian; Xian, Hui; Tan, Yi-Sheng; Jiang, Zheng; Taguchi, Akira; Inoue, Mitsuhiro; Yoneyama, Yoshiharu; Abe, Takayuki; Tsubaki, Noritatsu

    2013-01-01

    To substitute for petroleum, Fischer-Tropsch synthesis (FTS) is an environmentally benign process to produce synthetic diesel (n-paraffin) from syngas. Industrially, the synthetic gasoline (iso-paraffin) can be produced with a FTS process followed by isomerization and hydrocracking processes over solid-acid catalysts. Herein, we demonstrate a cobalt nano-catalyst synthesized by physical-sputtering method that the metallic cobalt nano-particles homogeneously disperse on the H-ZSM5 zeolite support with weak Metal-Support Interactions (MSI). This catalyst performed the high gasoline-range iso-paraffin productivity through the combined FTS, isomerization and hydrocracking reactions. The weak MSI results in the easy reducibility of the cobalt nano-particles; the high cobalt dispersion accelerates n-paraffin diffusion to the neighboring acidic sites on the H-ZSM5 support for isomerization and hydrocracking. Both factors guarantee its high CO conversion and iso-paraffin selectivity. This physical-sputtering technique to synthesize the supported metallic nano-catalyst is a promising way to solve the critical problems caused by strong MSI for various processes. PMID:24085106

  9. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    NASA Astrophysics Data System (ADS)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  10. Stable performance of non‐aerated two‐stage partial nitritation/anammox (PANAM) with minimal process control

    PubMed Central

    Bagchi, Samik; Biswas, Rima; Vlaeminck, Siegfried E.; Roychoudhury, Kunal; Nandy, Tapas

    2012-01-01

    Summary Partial nitritation/anammox (PANAM) technologies have rapidly developed over the last decade, but still considerable amounts of energy are required for active aeration. In this study, a non‐aerated two‐stage PANAM process was investigated. In the first‐stage upflow fixed‐film bioreactor, nitratation could not be prevented at ammonium loading rates up to 186 mg N l−1 d−1 and low influent dissolved oxygen (0.1 mg O2 l−1). Yet, increasing the loading rate to 416 and 747 mg N l−1 d−1 by decreasing the hydraulic retention time to 8 and 5 h, respectively, resulted in partial nitritation with the desired nitrite to ammonium nitrogen ratio for the subsequent anammox stage (0.71–1.05). The second‐stage anammox reactor was established with a synthetic feeding based on ammonium and nitrite. After establishing anammox at low biomass content (0.5 g VSS l−1), the anammox influent was switched to partial nitritation effluent at a loading rate of 71 mg N l−1 d−1, of which 78% was removed at the stoichiometrically expected nitrite to ammonium consumption ratios (1.19) and nitrate production to ammonium consumption ratio (0.24). The combined PANAM reactors were operated for 3 months at a stable performance. Overall, PANAM appeals economically, saving about 50% of the energy costs, as well as technically, given straightforward operational principles. PMID:22414169

  11. Metrics, Dollars, and Systems Change: Learning from Washington State's Student Achievement Initiative to Design Effective Postsecondary Performance Funding Policies. A State Policy Brief

    ERIC Educational Resources Information Center

    Jenkins, Davis; Shulock, Nancy

    2013-01-01

    The Student Achievement Initiative (SAI), adopted by the Washington State Board for Community and Technical Colleges in 2007, is one of a growing number of performance funding programs that have been dubbed "performance funding 2.0." Unlike previous performance funding models, the SAI rewards colleges for students' intermediate achievements along…

  12. Test Scores, School Performance and Parenting Issues: Assuring Academic Achievement. The Connection between Family Life and School Achievement: Given a Supportive Family, Black Children Can Succeed.

    ERIC Educational Resources Information Center

    Williams, Wanda A.

    Two things in particular could change the status of students of color in our elementary and secondary education system and make improved academic achievement possible. One is providing role models that students can relate to in the classrooms, and the other is getting families involved in their children's education. A study on family life and…

  13. Evidence-based surgical training in orthopaedics: how many arthroscopies of the knee are needed to achieve consultant level performance?

    PubMed

    Price, A J; Erturan, G; Akhtar, K; Judge, A; Alvand, A; Rees, J L

    2015-10-01

    Despite being one of the most common orthopaedic operations, it is still not known how many arthroscopies of the knee must be performed during training in order to develop the skills required to become a Consultant. A total of 54 subjects were divided into five groups according to clinical experience: Novices (n = 10), Junior trainees (n = 10), Registrars (n = 18), Fellows (n = 10) and Consultants (n = 6). After viewing an instructional presentation, each subject performed a simple diagnostic arthroscopy of the knee on a simulator with visualisation and probing of ten anatomical landmarks. Performance was assessed using a validated global rating scale (GRS). Comparisons were made against clinical experience measured by the number of arthroscopies which had been undertaken, and ROC curve analysis was used to determine the number of procedures needed to perform at the level of the Consultants. There were marked differences between the groups. There was significant improvement in performance with increasing experience (p < 0.05). ROC curve analysis identified that approximately 170 procedures were required to achieve the level of skills of a Consultant. We suggest that this approach to identify what represents the level of surgical skills of a Consultant should be used more widely so that standards of training are maintained through the development of an evidenced-based curriculum. PMID:26430003

  14. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  15. Multimedia OC12 parallel interface using VCSEL array to achieve high-performance cost-effective optical interconnections

    NASA Astrophysics Data System (ADS)

    Chang, Edward S.

    1996-09-01

    ribbon cable, and MT connectors to achieve a high-performance, low-cost parallel link. A logical model of a multimedia server with parallel connections to an ATM switch, and to clients is presented. The design of the parallel optical link is analyzed. Furthermore, the link configured for testing, the test method, and test results are presented to confirm the analysis and to assure reliable link performance.

  16. The Effect of Retesting on End-of-Semester Performance in High School Chemistry at Three Levels of Previous Science Achievement.

    ERIC Educational Resources Information Center

    Deboer, George E.

    1981-01-01

    Examines whether retesting: (1) affects achievement of students (N=95) grouped according to previous achievement in science; and (2) influences students to delay studying and perform at a low level on initial tests. Also examines whether procrastination of retested students is affected by their achievement level. (DS)

  17. Stable silylenes.

    PubMed

    Haaf, M; Schmedake, T A; West, R

    2000-10-01

    The field of stable silylene research has grown dramatically since the first isolation of a stable silylene in 1994. Prior to 1994, silylenes existed only as reactive intermediates, isolable only in low-temperature matrixes. Since then, several stable silylenes have been synthesized, some in fact showing remarkable thermal stability. This Account highlights the developments in stable silylene chemistry, including theoretical and experimental studies attempting to explain the remarkable stability of the silylenes as well as the rapidly expanding reaction chemistry of the stable silylenes. PMID:11041835

  18. Quality of Education Predicts Performance on the Wide Range Achievement Test-4th Edition Word Reading Subtest

    PubMed Central

    Sayegh, Philip; Arentoft, Alyssa; Thaler, Nicholas S.; Dean, Andy C.; Thames, April D.

    2014-01-01

    The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtest's construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic variables and predicted global neurocognitive functioning after adjusting for WRAT-4. As expected, race/ethnicity and education predicted WRAT-4 reading performance. Hierarchical regression revealed that when including education quality, the amount of WRAT-4's explained variance increased significantly, with race/ethnicity and both education quality and years as significant predictors. Finally, WRAT-4 scores, but not education quality, predicted neurocognitive performance. Results support WRAT-4 Word Reading as a valid proxy measure for education quality and a key predictor of neurocognitive performance. Future research should examine these findings in larger, more diverse samples to determine their robust nature. PMID:25404004

  19. Quality of education predicts performance on the Wide Range Achievement Test-4th Edition Word Reading subtest.

    PubMed

    Sayegh, Philip; Arentoft, Alyssa; Thaler, Nicholas S; Dean, Andy C; Thames, April D

    2014-12-01

    The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtest's construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic variables and predicted global neurocognitive functioning after adjusting for WRAT-4. As expected, race/ethnicity and education predicted WRAT-4 reading performance. Hierarchical regression revealed that when including education quality, the amount of WRAT-4's explained variance increased significantly, with race/ethnicity and both education quality and years as significant predictors. Finally, WRAT-4 scores, but not education quality, predicted neurocognitive performance. Results support WRAT-4 Word Reading as a valid proxy measure for education quality and a key predictor of neurocognitive performance. Future research should examine these findings in larger, more diverse samples to determine their robust nature. PMID:25404004

  20. Case study: Comparison of motivation for achieving higher performance between self-directed and manager-directed aerospace engineering teams

    NASA Astrophysics Data System (ADS)

    Erlick, Katherine

    "The stereotype of engineers is that they are not people oriented; the stereotype implies that engineers would not work well in teams---that their task emphasis is a solo venture and does not encourage social aspects of collaboration" (Miner & Beyerlein, 1999, p. 16). The problem is determining the best method of providing a motivating environment where design engineers may contribute within a team in order to achieve higher performance in the organization. Theoretically, self-directed work teams perform at higher levels. But, allowing a design engineer to contribute to the team while still maintaining his or her anonymity is the key to success. Therefore, a motivating environment must be established to encourage greater self-actualization in design engineers. The purpose of this study is to determine the favorable motivational environment for design engineers and describe the comparison between two aerospace design-engineering teams: one self-directed and the other manager directed. Following the comparison, this study identified whether self-direction or manager-direction provides the favorable motivational environment for operating as a team in pursuit of achieving higher performance. The methodology used in this research was the case study focusing on the team's levels of job satisfaction and potential for higher performance. The collection of data came from three sources, (a) surveys, (b) researcher observer journal and (c) collection of artifacts. The surveys provided information regarding personal behavior characteristics, potentiality for higher performance and motivational attributes. The researcher journal provided information regarding team dynamics, individual interaction, conflict and conflict resolution. The milestone for performance was based on the collection of artifacts from the two teams. The findings from this study illustrated that whether the team was manager-directed or self-directed does not appear to influence the needs and wants of the

  1. Functional Organosulfide Electrolyte Promotes an Alternate Reaction Pathway to Achieve High Performance in Lithium-Sulfur Batteries.

    PubMed

    Chen, Shuru; Dai, Fang; Gordin, Mikhail L; Yu, Zhaoxin; Gao, Yue; Song, Jiangxuan; Wang, Donghai

    2016-03-18

    Lithium-sulfur (Li-S) batteries have recently received great attention because they promise to provide energy density far beyond current lithium ion batteries. Typically, Li-S batteries operate by conversion of sulfur to reversibly form different soluble lithium polysulfide intermediates and insoluble lithium sulfides through multistep redox reactions. Herein, we report a functional electrolyte system incorporating dimethyl disulfide as a co-solvent that enables a new electrochemical reduction pathway for sulfur cathodes. This pathway uses soluble dimethyl polysulfides and lithium organosulfides as intermediates and products, which can boost cell capacity and lead to improved discharge-charge reversibility and cycling performance of sulfur cathodes. This electrolyte system can potentially enable Li-S batteries to achieve high energy density. PMID:26918660

  2. Design and Performance Assessment of a Stable Astigmatic Herriott Cell for Trace Gas Measurements on Airborne Platforms

    NASA Technical Reports Server (NTRS)

    Dyroff, Christoph; Fried, Alan; Richter, Dirk; Walega, James G.; Zahniser, Mark S.; McManus, J. Barry

    2005-01-01

    The present paper discusses a new, more stable, astigmatic Herriott cell employing carbon fiber stabilizing rods. Laboratory tests using a near-IR absorption feature of CO at 1564.168-nm revealed a factor of two improvement in measurement stability compared with the present commercial design when the sampling pressure was changed by +/-2 Torr around 50 Torr. This new cell should significantly enhance our efforts to measure trace gases employing pathlengths of 100 to 200-meters on airborne platforms with minimum detectable line center absorbances of less than 10(exp -6).

  3. Configurable three-dimensional boron nitride-carbon architecture and its tunable electronic behavior with stable thermal performances.

    PubMed

    Loeblein, Manuela; Tay, Roland Yingjie; Tsang, Siu Hon; Ng, Wei Beng; Teo, Edwin Hang Tong

    2014-08-13

    Recent developments of 3D-graphene and 3D-boron-nitride have become of great interest owing to their potential for ultra-light flexible electronics. Here we demonstrate the first synthesis of novel 3D-BNC hybrids. By specifically controlling the compositions of C and BN, new fascinating properties are observed, such as highly tunable electrical conductivity, controllable EMI shielding properties, and stable thermal conductivity. This ultra-light hybrid opens up many new applications such as for electronic packaging and thermal interface materials (TIMs). PMID:24789084

  4. A Software Toolkit and Interface for Performing Stable Isotope Labeling and Top3 Quantification Using Progenesis LC-MS

    PubMed Central

    Brownridge, Philip; Xia, Dong; Mackay, Katherine; Gonzalez-Galarza, Faviel F.; Kenyani, Jenna; Harman, Victoria; Beynon, Robert J.; Jones, Andrew R.

    2012-01-01

    Abstract Numerous software packages exist to provide support for quantifying peptides and proteins from mass spectrometry (MS) data. However, many support only a subset of experimental methods or instrument types, meaning that laboratories often have to use multiple software packages. The Progenesis LC-MS software package from Nonlinear Dynamics is a software solution for label-free quantitation. However, many laboratories using Progenesis also wish to employ stable isotope-based methods that are not natively supported in Progenesis. We have developed a Java programming interface that can use the output files produced by Progenesis, allowing the basic MS features quantified across replicates to be used in a range of different experimental methods. We have developed post-processing software (the Progenesis Post-Processor) to embed Progenesis in the analysis of stable isotope labeling data and top3 pseudo-absolute quantitation. We have also created export ability to the new data standard, mzQuantML, produced by the Proteomics Standards Initiative to facilitate the development and standardization process. The software is provided to users with a simple graphical user interface for accessing the different features. The underlying programming interface may also be used by Java developers to develop other routines for analyzing data produced by Progenesis. PMID:22888986

  5. An Examination of Teachers' Effects on High, Middle, and Low Aptitude Students' Performance on a Standardized Achievement Test

    ERIC Educational Resources Information Center

    Good, Thomas L.; Beckerman, Terrill M.

    1978-01-01

    Teacher effectiveness was defined by students' mathematics score on the Iowa Test of Basic Skills while achievement was measured by the Cognitive Abilities Test. Relatively effective teachers generally produced achievement gains from all aptitude levels. Similarly, relatively ineffective teachers did not disproportionately depress achievement for…

  6. Predictive Indicators of High Performing Schools: A Study of Evaluative Inquiry and the Effective Use of Achievement Test Data

    ERIC Educational Resources Information Center

    Hill, Kathryn L.

    2010-01-01

    Existing research suggests a link between evaluative inquiry (EI) and student achievement, where EI is defined as the practice of analyzing student achievement data to identify ways to improve instruction. However, researchers lacked empirical evidence regarding the relationship between specific EI indicators and student achievement. The purpose…

  7. Stable poly(St-co-BA) nanoemulsion polymerization for high performance antibacterial coatings in the presence of dioctyldimethylammonium chloride.

    PubMed

    Chen, Zhao; Sun, Xiaowen; Shen, Yan; Ni, Hong; Chai, Shigan; Zou, Qichao; Zhang, Xiuhua; Zhang, Jinzhi

    2015-04-01

    In this study, a stable antibacterial poly(styrene-co-butyl acrylate) (poly(St-co-BA)) nano-latex was prepared in the presence of a dioctyldimethylammonium chloride (D821)-CTAB mixed surfactant and a novel bis-unsaturated Gemini comonomer (i.e., α,ω-hexanediyl bis(dimethyl methacrylamidopropyl ammonium bromide) (GMAP-6-MAP)) using a feasible and mild semicontinuous technology. The effects of the emulsifiers and GMAP-6-MAP on the properties and antibacterial activities of poly(St-co-BA) coatings were systematically investigated. The results indicate that an optimal monodispersed stable nanoemulsion was obtained with Dw=58.24nm and PDI=0.026, the emulsifier amount was 3.75% (D821/CTAB=4:1), and the GMAP-6-MAP amount was 1.5%. CTAB improved the stabilities and antibacterial activities of the poly(St-co-BA) nanoemulsions. The incorporation of GMAP-6-MAP into poly(St-co-BA) can enhance the antibacterial activity, improve the thermal stability of latex films, as well as the consistency among the chain segments, and decrease the roughness of latex films. This nanoemulsion exhibits effective antibacterial activity with MBCs of 2μg·mL(-1) against Staphylococcus aureus and 16μg·mL(-1) against Escherichia coli. The sterilization rates of the optimized latex film reached 100% against S. aureus and 98.74% against E. coli, which indicated that this latex film could be utilized as an outstanding antibacterial coating. PMID:25686944

  8. Sex Differences in Performance Attributions, Self-Efficacy, and Achievement in Mathematics: If I'm So Smart, Why Don't I Know It?

    ERIC Educational Resources Information Center

    Lloyd, Jennifer E. V.; Walsh, John; Yailagh, Manizheh Shehni

    2005-01-01

    In this study, we tested the claim that sex differences in mathematics achievement are related to boys' and girls' differing achievement-related beliefs. We compared the mathematics report card grades, 2001 Foundation Skills Assessment (FSA) Numeracy subtest scores, performance attributions, and self-efficacy of 161 British Columbian public school…

  9. Achievement Gaps: How Hispanic and White Students in Public Schools Perform in Mathematics and Reading on the National Assessment of Educational Progress. Highlights. NCES 2011-485

    ERIC Educational Resources Information Center

    National Center for Education Statistics, 2011

    2011-01-01

    This report provides a detailed portrait of Hispanic and White academic achievement gaps and how students' performance has changed over time at both the national and state levels. The report presents achievement gaps using reading and mathematics assessment data from the National Assessment of Educational Progress (NAEP) for the 4th- and 8th-grade…

  10. The potential influence of perception of achievement on performance in volitional time-to-exhaustion cycle ergometer trials.

    PubMed

    Lorimer, Ross; Babraj, John

    2013-06-01

    The purpose of this short communication was to report the findings of an investigation of the potential influence of spontaneous goal setting on subjects undertaking maximal fitness testing. Subjects were asked to complete a single incremental volitional time-to-exhaustion cycle ergometer trial. The final minute of the trial, after the last increase in increment in resistance, was broken down into six 10-second intervals and a frequency count made of how many subjects stopped within each interval. A chi-square test was used to determine that there was a significant difference between the expected and the observed frequencies (p < 0.05), with 45% of subjects stopping in the first interval (0-10 seconds) and 0% within the last interval (51-60 seconds). Reflections of the subjects revealed that those who were close to exhaustion but near to reaching the next increment of resistance were more likely to "push on." However, despite having been told to keep going as long as they could, subjects upon reaching that increment stopped almost immediately as they believed they could not manage to reach the next increment. This suggests a potential psychological element related to goal achievement that influences performance in incremental volitional time-to-exhaustion cycle ergometer trials. Practically, this means that the information participants have available on which to base goals (level of increment, time, etc.) needs to be minimized to prevent spontaneous goal setting. PMID:23037613

  11. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells.

    PubMed

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-01-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm(-1) in 5% H2 and peak power densities of 1.72 and 0.54 W cm(-2) using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm(-2). To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode. PMID:26648509

  12. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    PubMed Central

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-01-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm−1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm−2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm−2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode. PMID:26648509

  13. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-12-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm-1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm-2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm-2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode.

  14. Formation of stable phosphorus-carbon bond for enhanced performance in black phosphorus nanoparticle-graphite composite battery anodes.

    PubMed

    Sun, Jie; Zheng, Guangyuan; Lee, Hyun-Wook; Liu, Nian; Wang, Haotian; Yao, Hongbin; Yang, Wensheng; Cui, Yi

    2014-08-13

    High specific capacity battery electrode materials have attracted great research attention. Phosphorus as a low-cost abundant material has a high theoretical specific capacity of 2596 mAh/g with most of its capacity at the discharge potential range of 0.4-1.2 V, suitable as anodes. Although numerous research progress have shown other high capacity anodes such as Si, Ge, Sn, and SnO2, there are only a few studies on phosphorus anodes despite its high theoretical capacity. Successful applications of phosphorus anodes have been impeded by rapid capacity fading, mainly caused by large volume change (around 300%) upon lithiation and thus loss of electrical contact. Using the conducting allotrope of phosphorus, "black phosphorus" as starting materials, here we fabricated composites of black phosphorus nanoparticle-graphite by mechanochemical reaction in a high energy mechanical milling process. This process produces phosphorus-carbon bonds, which are stable during lithium insertion/extraction, maintaining excellent electrical connection between phosphorus and carbon. We demonstrated high initial discharge capacity of 2786 mAh·g(-1) at 0.2 C and an excellent cycle life of 100 cycles with 80% capacity retention. High specific discharge capacities are maintained at fast C rates (2270, 1750, 1500, and 1240 mAh·g(-1) at C/5, 1, 2, and 4.5 C, respectively). PMID:25019417

  15. Performance of painted plywood and cloth Nzi traps relative to Manitoba and greenhead traps for tabanids and stable flies.

    PubMed

    Mihok, Steve; Carlson, David A

    2007-04-01

    Experiments were conducted to adapt the cloth Nzi trap to a format suitable for fixed applications in biting fly sampling or control. Catches of tabanids [Tabanus L., Chrysops (Meigen), and Hybomitra Enderlein], and stable flies [Stomoxys calcitrans (L.)] in painted plywood traps were compared with those in standard phthalogen blue cloth traps, and in similarly painted cloth traps. The Manitoba horse fly trap and the Tabanus nigrovittatus Macquart "greenhead" box trap were used as additional standards during one tabanid season. Shiny features of traps reduced catches, e.g., paint on cloth instead of wood, or use of aluminum screening instead of netting. Nevertheless, appropriately painted plywood Nzi traps caught as many biting flies as did standard cloth Nzi traps, if paint finishes were matte, and with the use of phthalogen blue colorants. Nzi traps collected about the same tabanid fauna as the Manitoba and T. nigrovittatus traps, but with improved catches of Chrysops and Tabanus. Recommendations are provided on appropriate color matching, and selection of readily-available materials for trap construction. PMID:17461091

  16. Associative Verbal Encoding (a/v/e): A Measure of Language Performance and Its Relationship to Reading Achievement.

    ERIC Educational Resources Information Center

    Mickelson, Norma Irene

    After establishing reliability for an associative verbal encoding (a/v/e) test, the relationship between children's a/v/e and their reading achievement was investigated. Two hypotheses were examined: (1) a/v/e will improve with training, and (2) associated with improved a/v/e will be concomitant improvement in reading achievement. The subjects…

  17. Performance Assessment of High and Low Income Families through "Online RAW Achievement Battery Test" of Primary Grade Students

    ERIC Educational Resources Information Center

    Ahmed, Tamim; Hanif, Maria

    2016-01-01

    This study is intended to investigate student's achievement capability among two families i.e. Low and High income families and designed for primary level learners. A Reading, Arithmetic and Writing (RAW) Achievement test that was developed as a part of another research study (Tamim Ahmed Khan, 2015) was adopted for this study. Both English medium…

  18. Development and Validation of a Physics Achievement Test to Identify Instructor Variables Associated with Students' Physics Academic Performance

    ERIC Educational Resources Information Center

    Lacambra, Wilfredo T.

    2016-01-01

    One of the most common ways of detecting whether an improvement is achieved by an education institution is through measuring the students' achievement in a test. Testing is generally thought of as a means of assessing the knowledge and skills students have acquired through learning (Du-chastel and Nungester, 1998). Test results, besides assisting…

  19. Co-Percolating Graphene-Wrapped Silver Nanowire Network for High Performance, Highly Stable, Transparent Conducting Electrodes

    SciTech Connect

    Chen, Ruiyi; Das, Suprem R; Jeong, Changwook; Khan, Mohammad Ryyan; Janes, David B; Alam, Muhammad A

    2013-04-25

    Transparent conducting electrodes (TCEs) require high transparency and low sheet resistance for applications in photovoltaics, photodetectors, flat panel displays, touch screen devices, and imagers. Indium tin oxide (ITO), or other transparent conductive oxides, have been used, and provide a baseline sheet resistance (RS) vs. transparency (T) relationship. Several alternative material systems have been investigated. The development of high-performance hybrid structures provides a route towards robust, scalable and low-cost approaches for realizing high-performance TCE.

  20. Low Defect FeFe(CN)6 Framework as Stable Host Material for High Performance Li-Ion Batteries.

    PubMed

    Wu, Xianyong; Shao, Miaomiao; Wu, Chenghao; Qian, Jiangfeng; Cao, Yuliang; Ai, Xinping; Yang, Hanxi

    2016-09-14

    Low cost and high performance Li-ion batteries have been extensively pursued for grid-scale energy storage applications; however, their development has been impeded for a long time due to the lack of qualified cathode materials with not only decent electrochemical performance but also resource abundance and low price. In this paper, we report Prussian-blue type FeFe(CN)6 nanocrystals with well-controlled lattice defects and perfect nanocubic morphology, which can exhibit a high Li-storage capacity of 160 mAh g(-1), a strong rate performance at 24 C, and a superior cycle stability with 90% capacity retention over 300 cycles. This low defect lattice and its excellent Li-insertion performance might provide a new insight into the design of advanced Li-ion battery materials and also a competitive alternative to the presently developed Li(+) insertion cathodes to develop low cost and high performance Li-ion batteries for grid-scale energy storage applications. PMID:27556906

  1. Correlations among Six Learner Variables and the Performance of a Sample of Jamaican Eleventh-Graders on an Achievement Test on Respiration

    ERIC Educational Resources Information Center

    Soyibo, Kola; Pinnock, Jacqueline

    2005-01-01

    This study aimed at establishing if the level of performance of 500 Jamaican Grade 11 students on an achievement test on the concept of respiration was satisfactory (mean = 28 or 70% and above) or not (less than 70%); if there were statistically significant differences in their performance on the concept linked to their gender, cognitive abilities…

  2. WWC Review of the Report "Daily Online Testing in Large Classes: Boosting College Performance While Reducing Achievement Gaps." What Works Clearinghouse Single Study Review

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2014

    2014-01-01

    The 2013 study, "Daily Online Testing in Large Classes: Boosting College Performance While Reducing Achievement Gaps," examined the impact of frequent online testing and immediate feedback on the academic performance of college students. The study was conducted at the University of Texas in the fall of 2008 and 2011. Researchers found…

  3. PRED treatment mediated stable and efficient water oxidation performance of the Fe2O3 nano-coral structure

    NASA Astrophysics Data System (ADS)

    Shinde, Pravin S.; Lee, Hyun Hwi; Lee, Su Yong; Lee, Young Mi; Jang, Jum Suk

    2015-09-01

    Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mott-Schottky) analyses were performed to understand the effect of PRED treatment on the PEC performance of fabricated photoanodes. It is revealed that air-exposed Fe foil is prone to formation of a loosely bound surface oxide layer that, upon annealing at 800 °C, results in an unstable Fe2O3 nano-flake (2-3 μm long) morphology. In contrast, when such Fe foil is pre-treated with PRED to etch the loosely bound oxide layer, adherent inverse-opal-like nano-coral structures (60-100 nm thin) are formed. In addition to stability improvement, PRED-treatment also assists in exposing the photocatalytically active high index [104] facet sites of hematite. Thin hematite nano-coral structures with high index [104] facet sites significantly improved the separation of photo-generated charge carriers and oxygen evolution kinetics, resulting in performance enhancement with excellent photocurrent stability for extended duration in a 1 M NaOH solution under one sun illumination. The net photocurrent density for nano-coral morphology was 0.813 mA cm-2 at 1.23 V vs. RHE, which is the highest reported value for pristine hematite photoanodes fabricated from Fe foil.Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mott-Schottky) analyses were performed to

  4. PRED treatment mediated stable and efficient water oxidation performance of the Fe2O3 nano-coral structure.

    PubMed

    Shinde, Pravin S; Lee, Hyun Hwi; Lee, Su Yong; Lee, Young Mi; Jang, Jum Suk

    2015-09-28

    Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mott-Schottky) analyses were performed to understand the effect of PRED treatment on the PEC performance of fabricated photoanodes. It is revealed that air-exposed Fe foil is prone to formation of a loosely bound surface oxide layer that, upon annealing at 800 °C, results in an unstable Fe2O3 nano-flake (2-3 μm long) morphology. In contrast, when such Fe foil is pre-treated with PRED to etch the loosely bound oxide layer, adherent inverse-opal-like nano-coral structures (60-100 nm thin) are formed. In addition to stability improvement, PRED-treatment also assists in exposing the photocatalytically active high index [104] facet sites of hematite. Thin hematite nano-coral structures with high index [104] facet sites significantly improved the separation of photo-generated charge carriers and oxygen evolution kinetics, resulting in performance enhancement with excellent photocurrent stability for extended duration in a 1 M NaOH solution under one sun illumination. The net photocurrent density for nano-coral morphology was 0.813 mA cm(-2) at 1.23 V vs. RHE, which is the highest reported value for pristine hematite photoanodes fabricated from Fe foil. PMID:26300305

  5. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmasa)

    NASA Astrophysics Data System (ADS)

    Garofalo, A. M.; Burrell, K. H.; Eldon, D.; Grierson, B. A.; Hanson, J. M.; Holland, C.; Huijsmans, G. T. A.; Liu, F.; Loarte, A.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Solomon, W. M.; Turnbull, A. D.; Zeng, L.

    2015-05-01

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named "Super H-mode" because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

  6. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas

    SciTech Connect

    Garofalo, A. M. Burrell, K. H.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Turnbull, A. D.; Eldon, D.; Grierson, B. A.; Solomon, W. M.; Hanson, J. M.; Holland, C.; Huijsmans, G. T. A.; Liu, F.; Loarte, A.; Zeng, L.

    2015-05-15

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

  7. Furazans with Azo Linkages: Stable CHNO Energetic Materials with High Densities, Highly Energetic Performance, and Low Impact and Friction Sensitivities.

    PubMed

    Qu, Yanyang; Zeng, Qun; Wang, Jun; Ma, Qing; Li, Hongzhen; Li, Haibo; Yang, Guangcheng

    2016-08-22

    Various highly energetic azofurazan derivatives were synthesized by simple and efficient chemical routes. These nitrogen-rich materials were fully characterized by FTIR spectroscopy, elemental analysis, multinuclear NMR spectroscopy, and high-resolution mass spectrometry. Four of them were further confirmed structurally by single-crystal X-ray diffraction. These compounds exhibit high densities, ranging from 1.62 g cm(-3) up to a remarkably high 2.12 g cm(-3) for nitramine-substituted azofurazan DDAzF (2), which is the highest yet reported for an azofurazan-based CHNO energetic compound and is a consequence of the formation of strong intermolecular hydrogen-bonding networks. From the heats of formation, calculated with Gaussian 09, and the experimentally determined densities, the energetic performances (detonation pressure and velocities) of the materials were ascertained with EXPLO5 v6.02. The results suggest that azofurazan derivatives exhibit excellent detonation properties (detonation pressures of 21.8-46.1 GPa and detonation velocities of 6602-10 114 m s(-1) ) and relatively low impact and friction sensitivities (6.0-80 J and 80-360 N, respectively). In particular, they have low electrostatic spark sensitivities (0.13-1.05 J). These properties, together with their high nitrogen contents, make them potential candidates as mechanically insensitive energetic materials with high-explosive performance. PMID:27439332

  8. Fifteen Years of Collaborative Innovation and Achievement: NASA Nebraska Space Grant Consortium 15-Year Program Performance and Results Report

    NASA Technical Reports Server (NTRS)

    Schaaf, Michaela M.; Bowen, Brent D.; Fink, Mary M.; Nickerson, Jocelyn S.; Avery, Shelly; Carstenson, Larry; Dugan, James; Farritor, Shane; Joyce, James; Rebrovich, Barb

    2003-01-01

    Condensing five years of significant work into a brief narrative fitting PPR requirements gave the affiliates of the Nebraska Space Grant a valuable chance for reflection. Achievements of Space Grant in Nebraska were judiciously chosen for this document that best illustrate the resultant synergism of this consortium, keeping in mind that these examples are only a representation of greater activity throughout the state. Following are highlights of many of the finer and personal achievements for Nebraska Space Grant. The Consortium welcomes inquiries to elaborate on any of these accomplishments.

  9. Use of Student Achievement Information in the Performance Evaluation of Teachers in the Tennessee Career Ladder Program.

    ERIC Educational Resources Information Center

    Furtwengler, Carol B.

    Tennessee initiated a Career Ladder Program for teachers in July 1984. The program is designed to recruit, retain, and reward outstanding teachers. Teachers who obtain upper career ladder status receive financial rewards ranging from 2,000 to 7,000 dollars per year. This status is achieved by participation in a comprehensive evaluation process.…

  10. Comparing the Reading Performance of High-Achieving Adolescents: Computer-Based Testing versus Paper/Pencil

    ERIC Educational Resources Information Center

    Eno, Linda Peet

    2011-01-01

    Literacy is moving into the digital context. Many of the literacy tasks associated with higher education, the workplace, and civic life now take place in the digital world. Literacy in high school, however, languishes in the text world. This study compared the text literacy of a group of high-achieving 10th-grade students, to their digital…

  11. Closing the Achievement Gap: A Summer School Program to Accelerate the Academic Performance of Economically Disadvantaged Students

    ERIC Educational Resources Information Center

    Gonzalez, Ramon Michael

    2013-01-01

    With the increasing disparity in educational outcomes among economically and racially different groups of students, summer school has received attention from school reformers as a means to close the achievement gap. Given the interest in this topic by educators, researchers, and policymakers, there is little research on the impact of summer school…

  12. Expecting and Achieving Gains in Student Performance: EVAAS Value-Added Report 2002-2004 for the Archdiocese of Indianapolis

    ERIC Educational Resources Information Center

    Costello, Ronald W.; Shuey, Barbara

    2005-01-01

    The Archdiocese of Indianapolis has been using the Sander's value-added model to determine if they have had gains in student achievement in language arts, mathematics and reading. The article summarizes the method to make this determination and the results from three years of testing using the CTB McGraw-Hill Terre Nova test. The archdiocese has…

  13. The Impact of AP® Achievement Institute I on Students' AP Performance. Research Report No. 2012-7

    ERIC Educational Resources Information Center

    Bausmith, Jennifer Merriman; Laitusis, Vytas

    2012-01-01

    The AP Achievement Institute I (APAI I) is a four-day professional development program offered to teachers and administrators by EXCELerator™, a district reform program operated by the College Board. The APAI I program is designed to help teachers develop effective AP instructional strategies for a diverse student body and to help district,…

  14. Technology-Enhanced Assessment of Math Fact Automaticity: Patterns of Performance for Low- and Typically Achieving Students

    ERIC Educational Resources Information Center

    Stickney, Eric M.; Sharp, Lindsay B.; Kenyon, Amanda S.

    2012-01-01

    Because math fact automaticity has been identified as a key barrier for students struggling with mathematics, we examined how initial math achievement levels influenced the path to automaticity (e.g., variation in number of attempts, speed of retrieval, and skill maintenance over time) and the relation between attainment of automaticity and gains…

  15. A Study on the Impact of Military Parent Deployment on Student Performance; Academic Achievement, Absenteeism, Discipline, and Counselor Visits

    ERIC Educational Resources Information Center

    Arnold, Hilda

    2013-01-01

    The purpose of the study was to determine if parents' military deployment had an impact on the academic achievement of their children. The study examined if there were a parallel between parental military deployment and absenteeism, parental deployment and discipline, and parental deployment and counselor visits. The study also examined if…

  16. Surmounting the Challenges of Improving Academic Performance: Closing the Achievement Gap through Social-Emotional and Character Development

    ERIC Educational Resources Information Center

    Elias, Maurice J.; White, Gwyne; Stepney, Cesalie

    2014-01-01

    While educators and policy makers have an intuitive understanding of the influence of socioeconomic factors and race on student achievement, these factors make the current emphasis on standardized test scores as a primary criterion for evaluating schools and teachers indefensible and ineffective. The research presented illustrates the limits of…

  17. Five Social Disadvantages That Depress Student Performance: Why Schools Alone Can't Close Achievement Gaps. Report

    ERIC Educational Resources Information Center

    Morsy, Leila; Rothstein, Richard

    2015-01-01

    That students' social and economic characteristics shape their cognitive and behavioral outcomes is well established, yet policymakers typically resist accepting that non-school disadvantages necessarily depress outcomes. Rather, they look to better schools and teachers to close achievement gaps, and consistently come up short. This report…

  18. The Relationship between Student Achievement of At-Risk Students and the Georgia Performance Standards in Mathematics

    ERIC Educational Resources Information Center

    Hill, Loralee Ann

    2012-01-01

    Educational leaders continue to be challenged in terms of accountability measures for increased student achievement, as mandated by the No Child Left Behind Act of 2001 (NCLB). In particular, schools must show adequate yearly progress (AYP) reaching 100% proficiency levels for all students in the areas of English language arts and mathematics by…

  19. A Comparison of Stanford Achievement Test (SAT-9) Performance across Grade, Gender, Ethnicity, and Educational Program Placement.

    ERIC Educational Resources Information Center

    Sanchez, Kathryn; Kellow, Tom; Ye, Renmin

    This study compared Stanford Achievement Test (SAT-9) academic subtest scores by students' grade, gender, and ethnicity and across different educational programs (e.g., Title I and special education). The study sample consisted of 144,701 students from public schools in a large city in the Southwest United States (grades 1-11). Raw data were taken…

  20. What Educational Initiatives Contribute to Higher than Expected Achievement in Student Performance for Public Schools in the State of Indiana?

    ERIC Educational Resources Information Center

    Keeley, Thomas Allen

    2010-01-01

    The purpose of this study was to determine whether the areas of teaching methods, teacher-student relationships, school structure, school-community partnerships or school leadership were significantly embedded in practice and acted as a change agent among school systems that achieve higher than expected results on their state standardized testing…

  1. Faculty Sense of Academic Optimism and Its Relationship to Students' Achievement in Well Performing High Schools

    ERIC Educational Resources Information Center

    Cromartie, Michael Tyrone

    2013-01-01

    The aim of this study was to determine the organizational characteristics and behaviors that contribute to sustaining a culture of academic optimism as a mechanism of student achievement. While there is a developing research base identifying both the individual elements of academic optimism as well as the academic optimism construct itself as…

  2. Predicting Performance on State Achievement Tests Using Curriculum-Based Measurement in Reading: A Multilevel Meta-Analysis

    ERIC Educational Resources Information Center

    Yeo, Seungsoo

    2010-01-01

    The purpose of this synthesis was to examine the relationship between Curriculum-Based Measurement (CBM) and statewide achievement tests in reading. A multilevel meta-analysis was used to calculate the correlation coefficient of the population for 27 studies that met the inclusion criteria. Results showed an overall large correlation coefficient…

  3. Stable and High-Performance Flexible ZnO Thin-Film Transistors by Atomic Layer Deposition.

    PubMed

    Lin, Yuan-Yu; Hsu, Che-Chen; Tseng, Ming-Hung; Shyue, Jing-Jong; Tsai, Feng-Yu

    2015-10-14

    Passivation is a challenging issue for the oxide thin-film transistor (TFT) technologies because it requires prolonged high-temperature annealing treatments to remedy defects produced in the process, which greatly limits its manufacturability as well as its compatibility with temperature-sensitive materials such as flexible plastic substrates. This study investigates the defect-formation mechanisms incurred by atomic layer deposition (ALD) passivation processes on ZnO TFTs, based on which we demonstrate for the first time degradation-free passivation of ZnO TFTs by a TiO2/Al2O3 nanolaminated (TAO) film deposited by a low-temperature (110 °C) ALD process. By combining the TAO passivation film with ALD dielectric and channel layers into an integrated low-temperature ALD process, we successfully fabricate flexible ZnO TFTs on plastics. Thanks to the exceptional gas-barrier property of the TAO film (water vapor transmission rate (WVTR)<10(-6) g m(-2) day(-1)) as well as the defect-free nature of the ALD dielectric and ZnO channel layers, the TFTs exhibit excellent device performance with high stability and flexibility: field-effect mobility>20 cm2 V(-1) s(-1), subthreshold swing<0.4 V decade(-1) after extended bias-stressing (>10,000 s), air-storage (>1200 h), and bending (1.3 cm radius for 1000 times). PMID:26436832

  4. Controlled synthesis of series NixCo3-xO4 products: Morphological evolution towards quasi-single-crystal structure for high-performance and stable lithium-ion batteries

    PubMed Central

    Zhou, Yu; Liu, Yong; Zhao, Wenxia; Wang, Hai; Li, Baojun; Zhou, Xiang; Shen, Hui

    2015-01-01

    Transition metal oxides are very promising alternative anode materials for high-performance lithium-ion batteries (LIBs). However, their conversion reactions and concomitant volume expansion cause the pulverization, leading to poor cycling stability, which limit their applications. Here, we present the quasi-single-crystal NixCo3-xO4 hexagonal microtube (QNHM) composed of continuously twinned single crystal submicron-cubes as anode materials for LIBs with high energy density and long cycle life. At the current density of 0.8 A g−1, it can deliver a high discharge capacities of 1470 mAh g−1 over 100 cycles (105% of the 2nd cycle) and 590 mAh g−1 even after 1000 cycles. To better understand what underlying factors lead our QNHMs to achieve excellent electrochemical performance, a series of NixCo3-xO4 products with systematic shape evolution from spherical to polyhedral, and cubic particles as well as circular microtubes consisted of spheres and square microtubes composed of polyhedra have been synthesized. The excellent electrochemical performance of QNHMs is attributed to the unique stable quasi-single-crystal structure, which can both provide efficient electrical transport pathway and suppress the electrode pulverization. It is important to note that such quasi-single-crystal structure would be helpful to explore other high-energy lithium storage materials based on alloying or conversion reactions. PMID:26103885

  5. Controlled synthesis of series NixCo3-xO4 products: Morphological evolution towards quasi-single-crystal structure for high-performance and stable lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Liu, Yong; Zhao, Wenxia; Wang, Hai; Li, Baojun; Zhou, Xiang; Shen, Hui

    2015-06-01

    Transition metal oxides are very promising alternative anode materials for high-performance lithium-ion batteries (LIBs). However, their conversion reactions and concomitant volume expansion cause the pulverization, leading to poor cycling stability, which limit their applications. Here, we present the quasi-single-crystal NixCo3-xO4 hexagonal microtube (QNHM) composed of continuously twinned single crystal submicron-cubes as anode materials for LIBs with high energy density and long cycle life. At the current density of 0.8 A g-1, it can deliver a high discharge capacities of 1470 mAh g-1 over 100 cycles (105% of the 2nd cycle) and 590 mAh g-1 even after 1000 cycles. To better understand what underlying factors lead our QNHMs to achieve excellent electrochemical performance, a series of NixCo3-xO4 products with systematic shape evolution from spherical to polyhedral, and cubic particles as well as circular microtubes consisted of spheres and square microtubes composed of polyhedra have been synthesized. The excellent electrochemical performance of QNHMs is attributed to the unique stable quasi-single-crystal structure, which can both provide efficient electrical transport pathway and suppress the electrode pulverization. It is important to note that such quasi-single-crystal structure would be helpful to explore other high-energy lithium storage materials based on alloying or conversion reactions.

  6. Performance of human mass balance studies with stable isotope-labeled drug and continuous flow-isotope ratio mass spectrometry: a progress report.

    PubMed

    Browne, T R; Szabo, G K; Ajami, A; Browne, D G

    1998-04-01

    We propose performing human mass balance studies by administering stable isotope labeled (13C or 15N) drug and quantitating excess (above background) 13C or 15N in urine, serum, and feces by continuous flow-isotope ratio mass spectrometry (CF-IRMS). Theoretical calculations and empirical data (dynamic range, linearity, sensitivity, precision, accuracy) are presented to establish that commercially available CF-IRMS instruments can quantitate stable isotope labeled (one or two 15N or 13C labels) drug concentrations of 1.0 microg/mL or greater in urine, serum (15N), or feces. More than two 13C labels may be necessary to quantitate 1.0 microg/mL of drug in serum. Three volunteers received 650 mg of 15N13C2-acetaminophen, and urine was collected for 72 hours. Percent of administered label recovered in urine from the three subjects was 97.4, 78.9, and 95.4 for 13C and 90.3, 77.0, and 90.6 for 15N. Fecal recovery of label for one subject was 0.9% (13C2) and 1.1% (15N). Serum pharmacokinetic values obtained by counting 13C or 15N in one subject were as expected for acetaminophen. This method appears to be promising, and further validation is ongoing. PMID:9590457

  7. Dissolution performance of binary amorphous drug combinations--Impact of a second drug on the maximum achievable supersaturation.

    PubMed

    Trasi, Niraj S; Taylor, Lynne S

    2015-12-30

    An increased number of amorphous formulations of poorly water soluble drugs are being introduced into the market due to their higher transient solubility and thus faster absorption and higher bioavailability. While most amorphous drug products contain a single drug substance, there is a growing trend towards co-formulating compounds in the same dosage form to improve patient compliance. The purpose of the present work was to evaluate the dissolution behavior and maximum achievable solution concentrations of amorphous solid dispersions of co-formulated ritonavir and lopinavir, and to compare the results with individual amorphous solid dispersion formulations. Dispersions of ritonavir and lopinavir were prepared in polyvinylpyrrolidone (PVP) or hydroxypropylmethylcellulose acetate succinate (HPMCAS) at a 20% (w/w) total drug loading, both alone and in combination, at three different lopinavir:ritonavir weight ratios. Amorphous films containing both drugs, but no polymer, were also prepared. The dissolution behavior of the dispersions and the amorphous films in non-sink conditions was evaluated, using ultracentrifugation to separate any colloidal material from molecularly dissolved drug. Nanoparticle tracking analysis was used to characterize colloidal material formed during the dissolution process. Results from the dissolution study revealed that, although supersaturated solutions resulted following dissolution, the maximum achievable concentration of each drug, when present in combination, was dramatically lower than when the individual dispersions were dissolved. The maximum achievable solution concentration for systems containing both drugs was found to decrease as the mole fraction of the drug in the amorphous phase decreased. The type of polymer used to formulate the dispersion also appeared to influence the dissolution behavior whereby the HPMCAS dispersions dissolved rapidly, resulting in the generation of a nanodroplets, while the PVP dispersions did not

  8. The effect of retesting on end-of-semester performance in high school chemistry at three levels of previous science achievement

    NASA Astrophysics Data System (ADS)

    Deboer, George E.

    To determine the effect of retesting on student learning in chemistry, three questions were addressed by means of a 3 × 2 (achievement level X treatment) factorial design: (1) Does retesting affect differently the end-of-semester mastery of course objectives of students who are grouped according to their previous achievement in science? (2) Do students who are given an opportunity to take retests merely delay their studying and perform at a lower level on initial tests than nonretested students? (3) Is the procrastination of retested students (if it exists) affected by their achievement level? The results showed that for one of four units low ability students who were retested demonstrated greater learning gains than low ability students who were not retested, and that procrastination, if it was present, did not have significant effects on student learning at any achievement level. Results were discussed in terms of the students' room for improvement, motivation to improve, and ability to improve.

  9. Patterns and Predictors of Adolescent Academic Achievement and Performance in a Sample of Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

    PubMed Central

    Langberg, Joshua M.; Molina, Brooke S.G.; Arnold, L. Eugene; Epstein, Jeffery N.; Altaye, Mekibib; Hinshaw, Stephen P.; Swanson, James M.; Wigal, Timothy; Hechtman, Lily

    2011-01-01

    Examined predictors of academic achievement, measured by standardized test scores, and performance, measured by school grades, in adolescents (Mage=16.8 yr) who met diagnostic criteria for ADHD-Combined type in early childhood (Mage = 8.5; N = 579). Several mediation models were also tested to determine whether ADHD medication use, receipt of special education, classroom performance, homework completion, or homework management mediated the relationship between symptoms of ADHD and academic outcomes. Childhood predictors of adolescent achievement differed from those for performance. Classroom performance and homework management mediated the relationship between symptoms of inattention and academic outcomes. Implications for understanding the relationship between symptoms of ADHD and academic functioning are discussed. PMID:21722025

  10. The Effects of Intercollegiate Athletic Participation on Student Academic Achievement and Leadership Performance in a Selective Institution

    ERIC Educational Resources Information Center

    Yunker, Craig Andrew

    2009-01-01

    The purpose of this study was to examine the influence of various intensity levels of athletic participation on academic and leadership performance in a selective institution. For the purpose of this study a retrospective analysis of existing admissions and student performance data was conducted. The continuous dependent variables were academic…

  11. An investigation into the accuracy, stability and parallel performance of a highly stable explicit technique for stiff reaction-transport PDEs

    SciTech Connect

    Franz, A., LLNL

    1998-02-17

    The numerical simulation of chemically reacting flows is a topic, that has attracted a great deal of current research At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear Partial Differential Equations (PDES). Due to the stiffness that is usually present, explicit time differencing schemes are not used despite their inherent simplicity and efficiency on parallel and vector machines, since these schemes require prohibitively small numerical stepsizes. Implicit time differencing schemes, although possessing good stability characteristics, introduce a great deal of computational overhead necessary to solve the simultaneous algebraic system at each timestep. This thesis examines an algorithm based on a preconditioned time differencing scheme. The algorithm is explicit and permits a large stable time step. An investigation of the algorithm`s accuracy, stability and performance on a parallel architecture is presented

  12. The Impact of Prior Mathematics Achievement on the Relationship between High School Mathematics Curricula and Postsecondary Mathematics Performance, Course-Taking, and Persistence

    ERIC Educational Resources Information Center

    Post, Thomas R.; Medhanie, Amanuel; Harwell, Michael; Norman, Ke Wu; Dupuis, Danielle N.; Muchlinski, Thomas; Andersen, Edwin; Monson, Debra

    2010-01-01

    This retrospective study examined the impact of prior mathematics achievement on the relationship between high school mathematics curricula and student postsecondary mathematics performance. The sample (N = 4,144 from 266 high schools) was partitioned into 3 strata by ACT mathematics scores. Students completing 3 or more years of a commercially…

  13. A Comparative Case Study of Factors Distinguishing between High and Low-Performance on Reading Achievement in Elementary Rural Appalachian Schools

    ERIC Educational Resources Information Center

    Chambers, Jennifer; Hausman, Charles

    2014-01-01

    This qualitative comparative case study identified factors that distinguish between high and low-performance on reading achievement in elementary rural Appalachian schools. This study determined the most effective instructional reading strategies, as well as other influential factors, implemented by school districts in the rural Appalachia area…

  14. A Comparative Case Study of Factors Distinguishing between High and Low-Performance on Reading Achievement in Elementary Rural Appalachian Schools

    ERIC Educational Resources Information Center

    Chambers, Jennifer R.

    2012-01-01

    This qualitative comparative case study identified factors that distinguish between high and low-performance on reading achievement in elementary rural Appalachian schools. This study determined the most effective instructional reading strategies, as well as other influential factors, implemented by school districts in the rural Appalachia area…

  15. Test-Based Accountability and Student Achievement: An Investigation of Differential Performance on NAEP and State Assessments. NBER Working Paper No. 12817

    ERIC Educational Resources Information Center

    Jacob, Brian A.

    2007-01-01

    This paper explores the phenomenon referred to as test score inflation, which occurs when achievement gains on "high-stakes" exams outpace improvements on "low-stakes" tests. The first part of the paper documents the extent to which student performance trends on state assessments differ from those on the National Assessment of Educational Progress…

  16. How Does the Science Writing Heuristic Approach Affect Students' Performances of Different Academic Achievement Levels? A Case for High School Chemistry

    ERIC Educational Resources Information Center

    Kingir, Sevgi; Geban, Omer; Gunel, Murat

    2012-01-01

    This study investigates the effects of the Science Writing Heuristic (SWH), known as an argumentation-based science inquiry approach, on Grade 9 students' performance on a post-test in relation to their academic achievement levels. Four intact classes taught by 2 chemistry teachers from a Turkish public high school were selected for the study; one…

  17. Effects of Visual and Auditory Background on Reading Achievement Test Performance of Brain-Injured and Non Brain-Injured Children.

    ERIC Educational Resources Information Center

    Carter, John L.

    Forty-two brain injured boys and 42 non brain injured boys (aged 11-6 to 12-6) were tested to determine the effects of increasing amounts of visual and auditory distraction on reading performance. The Stanford Achievement Reading Comprehension Test was administered with three degrees of distraction. The visual distraction consisted of either very…

  18. The Impact of a State Takeover on Academic Achievement, School Performance, and School Leadership in a Rural South Carolina School District

    ERIC Educational Resources Information Center

    Bishop, Janice Zissette

    2009-01-01

    This case study on the impact of a state takeover in one of South Carolina's most rural school districts ("referred to as the County School District") was completed using a quasi-experimental mixed methods design to examine the impact on academic achievement, school performance, and school leadership as a result of the South Carolina Department of…

  19. The Effect of Performance Assessment-Driven Instruction on the Attitude and Achievement of Senior High School Students in Mathematics in Cape Coast Metropolis, Ghana

    ERIC Educational Resources Information Center

    Arhin, Ato Kwamina

    2015-01-01

    The study was a quasi-experimental research project conducted to investigate the effect of performance assessment-driven instructions on the attitude and achievement in mathematics of senior high school students in Ghana at Ghana National College in Cape Coast. Two Form 1 science classes were used for the study and were assigned as experimental…

  20. The Relationship between Students' Performance on the Cognitive Abilities Test (CogAT) and the Fourth and Fifth Grade Reading and Math Achievement Tests in Ohio

    ERIC Educational Resources Information Center

    Warnimont, Chad S.

    2010-01-01

    The purpose of this quantitative study was to examine the relationship between students' performance on the Cognitive Abilities Test (CogAT) and the fourth and fifth grade Reading and Math Achievement Tests in Ohio. The sample utilized students from a suburban school district in Northwest Ohio. Third grade CogAT scores (2006-2007 school year), 4th…

  1. Training for Telecommunications: Examining the Effects of Video- and Computer-Based Instruction on Preservice Teachers' Achievement, Near-Transfer Performance, and Perception of Instruction.

    ERIC Educational Resources Information Center

    Ivers, Karen S.; Barron, Ann E.

    1997-01-01

    Discusses the results of two different delivery methods (video and computer-based instruction) for teaching preservice educators how to use an electronic mail system. Analysis of student questionnaires and achievement found significant differences between the methods on students' perceptions of instruction and near-transfer performance (favoring…

  2. Building trust through promises and performance. Can your organization achieve the stellar results and employee loyalty found at Southwest Airlines?

    PubMed

    O'Connor, Edward J; Annison, Michael H

    2002-01-01

    Establishing a trusting relationship with your employees can help you transform your organization into a top performer. Examine how well-defined visions and goals are some of the keys to building that trust. PMID:11806234

  3. Fifteen Years of Collaborative Innovation and Achievement: NASA Nebraska Space Grant Consortium 15-Year Program Performance and Results Report

    NASA Technical Reports Server (NTRS)

    Schaaf, Michaela M. (Editor); Bowen, Brent D.; Fink, Mary M.; Nickerson, Jocelyn S.; Avery Shelly; Calamaio, Caprice; Carstenson, Larry; Dugan, James; Farr, Lynne; Farritor, Shane

    2003-01-01

    This 15-year evaluation serves as a summary document highlighting the numerous and complete successes of the Nebraska Space Grant Program. Innovation has been highlighted through significant new endeavors during this 5-year period, such as placement of students and faculty at NASA Centers and the expansion of NSGC Native American Outreach Programs. While the last national program evaluation resulted in Nebraska s ranking as the top Capability Enhancement Consortium, and 5th best overall, Nebraska felt there was room for significant growth and development. This has been validated through the recent competitive attainment of Designated Grant status and has allowed for the exploration of new initiatives, as well as the expansion of already successful programs. A comprehensive strategic planning effort has involved all Nebraska representative entities and has guided Nebraska Space Grant through the evaluation period, providing a basis for continual advancement. Nebraska rigorously employs evaluation techniques to ensure that stated outcomes and metrics are achieved and that weaknesses are identified and corrected. With this coordinated approach, Nebraska expects that the next 5 years will yield new opportunities for significant achievement. Nebraska Space Grant will embrace new national endeavors, including the integration of Pender Public Schools -Nebraska s NASA Explorer School, geospatial initiatives, and the National Student Satellite Program.

  4. Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

    SciTech Connect

    Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A.; Westlake, Karl R.; Cross, Karen Charlene; Allerman, Andrew Alan; Lee, Stephen Roger

    2011-12-01

    We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical spectroscopy to AlGaN epilayers to quantify deep level energies and densities and further correlate defect properties with AlGaN luminescence efficiency. We further review our development of p-type short period superlattice structures as an approach to mitigate the high acceptor activation energies in AlGaN alloys. Finally, we describe our laser diode fabrication process, highlighting the development of highly vertical and smooth etched laser facets, as well as characterization of resulting laser heterostructures.

  5. Employing low-temperature barriers to achieve strain-relaxed and high-performance GaN-based LEDs.

    PubMed

    Lin, Zhiting; Wang, Haiyan; Wang, Wenliang; Lin, Yunhao; Yang, Meijuan; Chen, Shuqi; Li, Guoqiang

    2016-05-30

    The epitaxial structure design of low-temperature barriers has been adopted to promote strain relaxation in multiple quantum well (MQWs) and achieve high-efficient GaN-based light-emitting diodes (LEDs). With these barriers, the relaxation value of wells increases from 0 to 4.59%. The strain-relaxed mechanism of low-temperature barriers is also discussed. The LED chip with the barriers grown at the TMIn flow of 75 sccm and the growth temperature of 830 °C has an optimal strain relaxation value of 1.53% in wells, and exhibits the largest light output power of 63.83 mW at the injection current of 65 mA, which is higher than that of conventional LED (51.89 mW) by 23%. In-depth studies reveal that the optimal low-temperature barriers remarkably promote the strain relaxation in wells without forming large density of crystalline defects. This achievement of high-efficiency LEDs sheds light on the future solid-state lighting applications. PMID:27410111

  6. Distress and academic achievement among adolescents of affluence: a study of externalizing and internalizing problem behaviors and school performance.

    PubMed

    Ansary, Nadia S; Luthar, Suniya S

    2009-01-01

    The main objectives of this study were to prospectively examine the relationship between externalizing (substance use and delinquency) and internalizing (depression and anxiety) dimensions and academic achievement (grades and classroom adjustment), as well as continuity over time in these domains, within a sample of wealthy adolescents followed from 10th to 12th grades (n = 256). In both parts of the study, cluster analyses were used to group participants at 10th grade and then group differences were evaluated on adjustment outcomes over time. In Part 1, problem behavior clusters revealed differences on academic indices with the two marijuana using groups--marijuana users and multiproblem youth--exhibiting the worst academic outcomes at all three waves. For Part 2, the two lowest achieving groups reported the highest distress across all externalizing dimensions over time. Stability across the three waves was found for both personal and academic competence as well as the associations between these two domains. Results are discussed in relation to intervention efforts targeting wealthy students at risk. PMID:19144236

  7. Stable electrical performance observed in large-scale monolayer WSe2(1-x)S2x with tunable band gap

    NASA Astrophysics Data System (ADS)

    Huang, Jian; Wang, Wenhui; Fu, Qi; Yang, Lei; Zhang, Kun; Zhang, Jingyu; Xiang, Bin

    2016-04-01

    Two-dimensional (2D) semiconductor materials have attracted broad interest due to their unique structures and physical properties. The stability of the 2D-material-based devices plays a key role in their practical applications. Here, we report the promising stable electrical performance in the large-scale monolayer WSe2(1-x)S2x with a tunable band gap. Photoluminescence (PL) spectroscopy was utilized to verify the tunable band gap in the as-grown monolayer with a tuning capability of 120 meV. Gated field effect transistor (FET) performance confirmed the p-type transport behavior in monolayer WSe2(1-x)S2x with a high on/off ratio (>104). Top-gated FET configuration improves the carrier mobility with two orders larger than that in the back-gated FET device. After exposure to air for three months, the device performance manifested excellent stability with no source-drain current drop observed. P-type WSe2(1-x)S2x with a tunable band gap is the ideal complement to n-type tunable monolayers in the application of pn junction-related flexible nanodevices.

  8. Stable electrical performance observed in large-scale monolayer WSe2(1-x)S2x with tunable band gap.

    PubMed

    Huang, Jian; Wang, Wenhui; Fu, Qi; Yang, Lei; Zhang, Kun; Zhang, Jingyu; Xiang, Bin

    2016-04-01

    Two-dimensional (2D) semiconductor materials have attracted broad interest due to their unique structures and physical properties. The stability of the 2D-material-based devices plays a key role in their practical applications. Here, we report the promising stable electrical performance in the large-scale monolayer WSe2(1-x)S2x with a tunable band gap. Photoluminescence (PL) spectroscopy was utilized to verify the tunable band gap in the as-grown monolayer with a tuning capability of 120 meV. Gated field effect transistor (FET) performance confirmed the p-type transport behavior in monolayer WSe2(1-x)S2x with a high on/off ratio (>10(4)). Top-gated FET configuration improves the carrier mobility with two orders larger than that in the back-gated FET device. After exposure to air for three months, the device performance manifested excellent stability with no source-drain current drop observed. P-type WSe2(1-x)S2x with a tunable band gap is the ideal complement to n-type tunable monolayers in the application of pn junction-related flexible nanodevices. PMID:26901119

  9. Highly Stable Silver Nanoplates for Surface Plasmon Resonance Biosensing

    SciTech Connect

    Gao, Chuanbo; Lu, Zhenda; Chi, Miaofang; Liu, ying; Cheng, Quan; Yin, Yadong

    2012-01-01

    An SPR biosensor was developed by employing highly stable Au-protected Ag nanoplates (NP) as enhancers (see picture). Superior performance was achieved by depositing a thin and uniform coating of Au on the Ag surface while minimizing disruptive galvanic replacement and retaining the strong surface plasmon resonance (SPR) of the silver nanoplates.

  10. Both Patient and Facility Contribute to Achieving the Centers for Medicare and Medicaid Services' Pay-for-Performance Target for Dialysis Adequacy

    PubMed Central

    Tighiouart, Hocine; Meyer, Klemens B.; Miskulin, Dana C.

    2011-01-01

    The Centers for Medicare and Medicaid Services (CMS) designated the achieved urea reduction ratio (URR) as a pay-for-performance measure, but to what extent this measure reflects patient characteristics and adherence instead of its intent to reflect facility performance is unknown. Here, we quantified the contributions of patient case-mix and adherence to the variability in achieving URR targets across dialysis facilities. We found that 92% of 10,069 hemodialysis patients treated at 173 facilities during the last quarter of 2004 achieved the target URR ≥65%. Mixed-effect models with random intercept for dialysis facility revealed a significant facility effect: 11.5% of the variation in achievement of target URR was attributable to the facility level. Adjusting for patient case-mix reduced the proportion of variation attributable to the facility level to 6.7%. Patient gender, body surface area, dialysis access, and adherence with treatment strongly associated with achievement of the URR target. We could not identify specific facility characteristics that explained the remaining variation between facilities. These data suggest that if adherence is not a modifiable patient characteristic, providers could be unfairly penalized for caring for these patients under current CMS policy. These penalties may have unintended consequences. PMID:22025629

  11. Optimizing Performance on Linux Clusters Using Advanced Communication Protocols: Achieving Over 10 Teraflops on a 8.6 Teraflops Linpack-Rated Linux Cluster

    SciTech Connect

    Krishnan, Manoj Kumar; Nieplocha, Jarek

    2005-04-26

    Advancements in high-performance networks (Quadrics, Infiniband or Myrinet) continue to improve the efficiency of modern clusters. However, the average application efficiency is as small fraction of the peak as the system’s efficiency. This paper describes techniques for optimizing application performance on Linux clusters using Remote Memory Access communication protocols. The effectiveness of these optimizations is presented in the context of an application kernel, dense matrix multiplication. The result was achieving over 10 teraflops on HP Linux cluster on which LINPACK performance is measured as 8.6 teraflops.

  12. A Descriptive-Comparative Study of Teacher Performance Evaluation on Student Achievement in a Public School District

    ERIC Educational Resources Information Center

    Christensen, William Howard

    2013-01-01

    In 2010, the federal government increased accountability expectations by placing more emphasis on monitoring teacher performance. Using a model that focuses on the New York State teacher evaluation system, that is comprised of a rubric for observation, local student assessment scores, and student state assessment scores, this…

  13. Supervised, Multivariate, Whole-Brain Reduction Did Not Help to Achieve High Classification Performance in Schizophrenia Research

    PubMed Central

    Janousova, Eva; Montana, Giovanni; Kasparek, Tomas; Schwarz, Daniel

    2016-01-01

    We examined how penalized linear discriminant analysis with resampling, which is a supervised, multivariate, whole-brain reduction technique, can help schizophrenia diagnostics and research. In an experiment with magnetic resonance brain images of 52 first-episode schizophrenia patients and 52 healthy controls, this method allowed us to select brain areas relevant to schizophrenia, such as the left prefrontal cortex, the anterior cingulum, the right anterior insula, the thalamus, and the hippocampus. Nevertheless, the classification performance based on such reduced data was not significantly better than the classification of data reduced by mass univariate selection using a t-test or unsupervised multivariate reduction using principal component analysis. Moreover, we found no important influence of the type of imaging features, namely local deformations or gray matter volumes, and the classification method, specifically linear discriminant analysis or linear support vector machines, on the classification results. However, we ascertained significant effect of a cross-validation setting on classification performance as classification results were overestimated even though the resampling was performed during the selection of brain imaging features. Therefore, it is critically important to perform cross-validation in all steps of the analysis (not only during classification) in case there is no external validation set to avoid optimistically biasing the results of classification studies. PMID:27610072

  14. Supervised, Multivariate, Whole-Brain Reduction Did Not Help to Achieve High Classification Performance in Schizophrenia Research.

    PubMed

    Janousova, Eva; Montana, Giovanni; Kasparek, Tomas; Schwarz, Daniel

    2016-01-01

    We examined how penalized linear discriminant analysis with resampling, which is a supervised, multivariate, whole-brain reduction technique, can help schizophrenia diagnostics and research. In an experiment with magnetic resonance brain images of 52 first-episode schizophrenia patients and 52 healthy controls, this method allowed us to select brain areas relevant to schizophrenia, such as the left prefrontal cortex, the anterior cingulum, the right anterior insula, the thalamus, and the hippocampus. Nevertheless, the classification performance based on such reduced data was not significantly better than the classification of data reduced by mass univariate selection using a t-test or unsupervised multivariate reduction using principal component analysis. Moreover, we found no important influence of the type of imaging features, namely local deformations or gray matter volumes, and the classification method, specifically linear discriminant analysis or linear support vector machines, on the classification results. However, we ascertained significant effect of a cross-validation setting on classification performance as classification results were overestimated even though the resampling was performed during the selection of brain imaging features. Therefore, it is critically important to perform cross-validation in all steps of the analysis (not only during classification) in case there is no external validation set to avoid optimistically biasing the results of classification studies. PMID:27610072

  15. Failure Is Not an Option (TM). Six Principles That Guide Student Achievement in High-Performing Schools

    ERIC Educational Resources Information Center

    Blankstein, Alan M.

    2004-01-01

    The author builds upon a foundation which identifies courageous school leadership and the professional learning community as the center of effective school reform. The author offers six guiding principles steps for creating and sustaining a high-performing school: (1) Common mission, vision, values, and goals: (2) Systems for prevention and…

  16. Teacher Discourse and Sixth Graders' Reported Affect and Achievement Behaviors in Two High-Mastery/High-Performance Mathematics Classrooms.

    ERIC Educational Resources Information Center

    Turner, Julianne C.; Meyer, Debra K.; Midgley, Carol; Patrick, Helen

    2003-01-01

    Examined the relation between the nature of teacher discourse and sixth-grade students' reports of affect and behavior in mathematics classrooms students perceived as emphasizing both mastery and performance goals. Found that students in the classroom in which there was constant and explicit support for autonomy and intrinsic motivation, positive…

  17. Performing History: The Effects of a Dramatic Art-Based History Program on Student Achievement and Enjoyment

    ERIC Educational Resources Information Center

    Otten, Mark; Stigler, James W.; Woodward, J. Arthur; Staley, Lisle

    2004-01-01

    This study examines the influence of a dramatic art-based history program for fifth-grade students on both their learning and enjoyment of history. The program, called "Performing History," reflects theories of effective use of drama in the classroom as well as successful ways to teach history. The program presents historical information as part…

  18. The Influence of Parenting Styles, Achievement Motivation, and Self-Efficacy on Academic Performance in College Students

    ERIC Educational Resources Information Center

    Turner, Erlanger A.; Chandler, Megan; Heffer, Robert W.

    2009-01-01

    Parenting styles have consistently been shown to relate to various outcomes such as youth psychopathology, behavior problems, and academic performance. Building on the research in the parenting style literature, along with examining components of self-determination theory, the present study examined the relations among authoritative parenting…

  19. Effects of p-(Trifluoromethoxy)benzyl and p-(Trifluoromethoxy)phenyl Molecular Architecture on the Performance of Naphthalene Tetracarboxylic Diimide-Based Air-Stable n-Type Semiconductors.

    PubMed

    Zhang, Dongwei; Zhao, Liang; Zhu, Yanan; Li, Aiyuan; He, Chao; Yu, Hongtao; He, Yaowu; Yan, Chaoyi; Goto, Osamu; Meng, Hong

    2016-07-20

    N,N'-Bis(4-trifluoromethoxyphenyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-POCF3) and N,N'-bis(4-trifluoromethoxybenzyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-BOCF3) have similar optical and electrochemical properties with a deep LUMO level of approximately 4.2 eV, but exhibit significant differences in electron mobility and molecular packing. NDI-POCF3 exhibits nondetectable charge mobility. Interestingly, NDI-BOCF3 shows air-stable electron transfer performance with enhanced mobility by increasing the deposition temperature onto the octadecyltrichlorosilane (OTS)-modified SiO2/Si substrates and achieves electron mobility as high as 0.7 cm(2) V(-1) s(-1) in air. The different mobilities of those two materials can be explained by several factors including thin-film morphology and crystallinity. In contrast to the poor thin-film morphology and crystallinity of NDI-POCF3, NDI-BOCF3 exhibits larger grain sizes and improved crystallinities due to the higher deposition temperature. In addition, the theoretical calculated transfer integrals of the intermolecular lowest unoccupied molecular orbital (LUMO) of the two materials further show that a large intermolecular orbital overlap of NDI-BOCF3 can transfer electron more efficiently than NDI-POCF3 in thin-film transistors. On the basis of fact that the theoretical calculations are consistent with the experimental results, it can be concluded that the p-(trifluoromethoxy) benzyl (BOCF3) molecular architecture on the former position of the naphthalene tetracarboxylic diimides (NDI) core provides a more effective way to enhance the intermolecular electron transfer property than the p-(trifluoromethoxy) phenyl (POCF3) group for the future design of NDI-related air-stable n-channel semiconductor. PMID:27355858

  20. Inverse modeling of surface-water discharge to achieve restoration salinity performance measures in Florida Bay, Florida

    USGS Publications Warehouse

    Swain, E.D.; James, D.E.

    2008-01-01

    The use of numerical modeling to evaluate regional water-management practices involves the simulation of various alternative water-delivery scenarios, which typically are designed intuitively rather than analytically. These scenario simulations are used to analyze how specific water-management practices affect factors such as water levels, flows, and salinities. In lieu of testing a variety of scenario simulations in a trial-and-error manner, an optimization technique may be used to more precisely and directly define good water-management alternatives. A numerical model application in the coastal regions of Florida Bay and Everglades National Park (ENP), representing the surface- and ground-water hydrology for the region, is a good example of a tool used to evaluate restoration scenarios. The Southern Inland and Coastal System (SICS) model simulates this area with a two-dimensional hydrodynamic surface-water model and a three-dimensional ground-water model, linked to represent the interaction of the two systems with salinity transport. This coastal wetland environment is of great interest in restoration efforts, and the SICS model is used to analyze the effects of alternative water-management scenarios. The SICS model is run within an inverse modeling program called UCODE. In this application, UCODE adjusts the regulated inflows to ENP while SICS is run iteratively. UCODE creates parameters that define inflow within an allowable range for the SICS model based on SICS model output statistics, with the objective of matching user-defined target salinities that meet ecosystem restoration criteria. Preliminary results obtained using two different parameterization methods illustrate the ability of the model to achieve the goals of adjusting the range and reducing the variance of salinity values in the target area. The salinity variance in the primary zone of interest was reduced from an original value of 0.509 psu2 to values 0.418 psu2 and 0.342 psu2 using different

  1. Some Suggested Techniques for Achieving Required Main Ring Low Level RF Performance for the Tevatron I Program

    SciTech Connect

    Griffin, J.E.; MacLachlan, J.

    1984-05-01

    These techniques are derived from experience with the existing low level rf system and from the results of accelerator experiments directed at the Tev I requirements which were performed using a specially modified low level rf system. The techniques suggested here are not necessarily unique and other techniques may be acceptable. It is important to realize that certain performance requirements on the Booster and Main Ring are substantially different in the Tev I program from those which have been acceptable in the fixed target program. For example, the longitudinal emittance of the bunches has been routinely and intentionally blown up by the 'bunch spreader' during acceleration to improve the smoothness of the spill. In the Tev I case, the 'bunch narrowing' procedure preceding {bar p} production and in bunch coalescing is facilitated by maintaining the smallest possible longitudinal emittance (i.e. the largest possible longitudinal phase space density). Also, during fixed target physics the Main Ring is essentially full (i.e. approx. 1090 of 1113 buckets occupied) so transient beam loading of the rf system is negligible except during injection, whereas for {bar p} production a single high intensity Booster batch (approx. 83 bunches) is to be accelerated causing substantial transient beam induced phase shift of the rf voltage during each passage. The low level phase and position error signals are normally derived from an essentially full ring during fixed target operation whereas in the Tev I program the systems must perform adequately with as few as ten adjacent buckets occupied. Because of the differences in emphasis between fixed target operation and Tevatron I operation is seems sensible to use separate low level rf systems for these two modes of operation. If a single low level system were to be used for both modes of operation some compromises may be necessary which might cause performance in either mode to be less than adequate. Because of the severe demands

  2. Adopting Novel Strategies in Achieving High-Performance Single-Layer Network Structured ZnO Nanorods Thin Film Transistors.

    PubMed

    Park, Ji-Hyeon; Park, Jee Ho; Biswas, Pranab; Kwon, Do Kyun; Han, Sun Woong; Baik, Hong Koo; Myoung, Jae-Min

    2016-05-11

    High-performance, solution-processed transparent and flexible zinc oxide (ZnO) nanorods (NRs)-based single layer network structured thin film transistors (TFTs) were developed on polyethylene terephthalate (PET) substrate at 100 °C. Keeping the process-temperature under 100 °C, we have improved the device performance by introducing three low temperature-based techniques; regrowing ZnO to fill the void spaces in a single layer network of ZnO NRs, passivating the back channel with polymer, and adopting ZrO2 as the high-k dielectric. Notably, high-k amorphous ZrO2 was synthesized and deposited using a novel method at an unprecedented temperature of 100 °C. Using these methods, the TFTs exhibited a high mobility of 1.77 cm(2)/V·s. An insignificant reduction of 2.18% in mobility value after 3000 cycles of dynamic bending at a radius of curvature of 20 mm indicated the robust mechanical nature of the flexible ZnO NRs SLNS TFTs. PMID:27096706

  3. The Development and Testing of Laboratory Performance Tasks for the Assessment of Achievement in High School Physics.

    NASA Astrophysics Data System (ADS)

    Boorman, Joan Marie

    The quest to stem "the rising tide of mediocrity" described in A Nation at Risk has prompted a myriad of changes in secondary science instruction. Appropriate assessments of these changes in curriculum are crucial to a meaningful evaluation of their effectiveness. Because the nature of many of the improvements has been to engage students in higher order thinking skills, simple paper and pencil tests are often inconclusive evaluation measures. Research has shown a more definitive assessment of a student's ability to apply higher order thinking skills is possible with tests of performance in problem-solving tasks in a science laboratory. The Physics Laboratory Skills Test (PLST) was developed as a prototype assessment instrument for evaluation of student ability to perform a range of process skills in the high school physics laboratory setting. The PLST included seven different items based on topics presented in a typical high school physics course. Each item constituted a separate laboratory performance test and was completed by individual students in a 40 minute class period. A sample of 219 physics students from rural, urban, public, and private schools in NY and PA were tested with the PLST in May 1990. Results of this study show that the PLST has usability, validity, and reliability as an assessment of basic skills (measuring and reporting) and higher order skills (planning and analysis). Participating teachers determined the PLST to be an appropriate and useful tool in evaluating individual student abilities. Content validity was established via evaluation by 'expert' high school physics teachers. The Pearson Correlation Coefficient was used to verify construct validity (r =.49) and inter-rater reliability (r =.81). The Cronbach Coefficient Alpha, which was used to determine internal consistency of each item, yielded strong positive results for the PLST. The outcomes of this study will be of particular interest to curriculum developers and classroom teachers

  4. Motivation and School Achievement.

    ERIC Educational Resources Information Center

    Maehr, Martin L.; Archer, Jennifer

    Addressing the question, "What can be done to promote school achievement?", this paper summarizes the literature on motivation relating to classroom achievement and school effectiveness. Particular attention is given to how values, ideology, and various cultural patterns impinge on classroom performance and serve to enhance motivation to achieve.…

  5. Sensitive, Efficient Quantitation of 13C-Enriched Nucleic Acids via Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry for Applications in Stable Isotope Probing

    PubMed Central

    Wilhelm, Roland; Szeitz, András; Klassen, Tara L.

    2014-01-01

    Stable isotope probing (SIP) of nucleic acids is a powerful tool for studying the functional traits of microbial populations within complex communities, but SIP involves a number of technical challenges. Many of the difficulties in DNA-SIP and RNA-SIP experiments can be effectively overcome with an efficient, sensitive method for quantitating the isotopic enrichment of nucleic acids. Here, we present a sensitive method for quantitating 13C enrichment of nucleic acids, requiring a few nanograms of sample, and we demonstrate its utility in typical DNA-SIP and RNA-SIP experiments. All five nucleobases (adenine, guanine, cytosine, thymine, and uracil) were separated and detected by using ultrahigh-performance liquid chromatography–tandem mass spectrometry. We detected all isotopic species in samples with as low as 1.5 atom% 13C above natural abundance, using 1-ng loadings. Quantitation was used to characterize the isotopic enrichment kinetics of cellulose- and lignin-based microcosm experiments and to optimize the recovery of enriched nucleic acids. Application of our method will minimize the quantity of expensive isotopically labeled substrates required and reduce the risk of failed experiments due to insufficient recovery of labeled nucleic acids for sequencing library preparation. PMID:25217022

  6. Strategies to optimize lithium-ion supercapacitors achieving high-performance: Cathode configurations, lithium loadings on anode, and types of separator

    NASA Astrophysics Data System (ADS)

    Cao, Wanjun; Li, Yangxing; Fitch, Brian; Shih, Jonathan; Doung, Tien; Zheng, Jim

    2014-12-01

    The Li-ion capacitor (LIC) is composed of a lithium-doped carbon anode and an activated carbon cathode, which is a half Li-ion battery (LIB) and a half electrochemical double-layer capacitor (EDLC). LICs can achieve much more energy density than EDLC without sacrificing the high power performance advantage of capacitors over batteries. LIC pouch cells were assembled using activated carbon (AC) cathode and hard carbon (HC) + stabilized lithium metal power (SLMP®) anode. Different cathode configurations, various SLMP loadings on HC anode, and two types of separators were investigated to achieve the optimal electrochemical performance of the LIC. Firstly, the cathode binders study suggests that the PTFE binder offers improved energy and power performances for LIC in comparison to PVDF. Secondly, the mass ratio of SLMP to HC is at 1:7 to obtain the optimized electrochemical performance for LIC among all the various studied mass ratios between lithium loading amounts and active anode material. Finally, compared to the separator Celgard PP 3501, cellulose based TF40-30 is proven to be a preferred separator for LIC.

  7. Performance-based tests versus behavioral ratings in the assessment of executive functioning in preschoolers: associations with ADHD symptoms and reading achievement.

    PubMed

    Miranda, Ana; Colomer, Carla; Mercader, Jessica; Fernández, M Inmaculada; Presentación, M Jesús

    2015-01-01

    The early assessment of the executive processes using ecologically valid instruments is essential for identifying deficits and planning actions to deal with possible adverse consequences. The present study has two different objectives. The first objective is to analyze the relationship between preschoolers' performance on tests of Working Memory and Inhibition and parents' and teachers' ratings of these executive functions (EFs) using the Behavior Rating Inventory of Executive Function (BRIEF). The second objective consists of studying the predictive value of the different EF measures (performance-based test and rating scales) on Inattention and Hyperactivity/Impulsivity behaviors and on indicators of word reading performance. The participants in the study were 209 children in the last year of preschool, their teachers and their families. Performance-based tests of Working Memory and Inhibition were administered, as well as word reading measures (accuracy and speed). The parents and teachers filled out rating scales of the EF and typical behaviors of attention deficit hyperactivity disorder (ADHD) symptomatology. Moderate correlation values were found between the different EF assessments procedures, although the results varied depending on the different domains. Metacognition Index from the BRIEF presented stronger correlations with verbal working memory tests than with inhibition tests. Both the rating scales and the performance-based tests were significant predictors of Inattention and Hyperactivity/Impulsivity behaviors and the reading achievement measures. However, the BRIEF explained a greater percentage of variance in the case of the ADHD symptomatology, while the performance-based tests explained reading achievement to a greater degree. The implications of the findings for research and clinical practice are discussed. PMID:25972833

  8. Performance-based tests versus behavioral ratings in the assessment of executive functioning in preschoolers: associations with ADHD symptoms and reading achievement

    PubMed Central

    Miranda, Ana; Colomer, Carla; Mercader, Jessica; Fernández, M. Inmaculada; Presentación, M. Jesús

    2015-01-01

    The early assessment of the executive processes using ecologically valid instruments is essential for identifying deficits and planning actions to deal with possible adverse consequences. The present study has two different objectives. The first objective is to analyze the relationship between preschoolers’ performance on tests of Working Memory and Inhibition and parents’ and teachers’ ratings of these executive functions (EFs) using the Behavior Rating Inventory of Executive Function (BRIEF). The second objective consists of studying the predictive value of the different EF measures (performance-based test and rating scales) on Inattention and Hyperactivity/Impulsivity behaviors and on indicators of word reading performance. The participants in the study were 209 children in the last year of preschool, their teachers and their families. Performance-based tests of Working Memory and Inhibition were administered, as well as word reading measures (accuracy and speed). The parents and teachers filled out rating scales of the EF and typical behaviors of attention deficit hyperactivity disorder (ADHD) symptomatology. Moderate correlation values were found between the different EF assessments procedures, although the results varied depending on the different domains. Metacognition Index from the BRIEF presented stronger correlations with verbal working memory tests than with inhibition tests. Both the rating scales and the performance-based tests were significant predictors of Inattention and Hyperactivity/Impulsivity behaviors and the reading achievement measures. However, the BRIEF explained a greater percentage of variance in the case of the ADHD symptomatology, while the performance-based tests explained reading achievement to a greater degree. The implications of the findings for research and clinical practice are discussed. PMID:25972833

  9. High-performance CaMKI: A highly active and stable form of CaMKIδ produced by high-level soluble expression in Escherichia coli.

    PubMed

    Senga, Yukako; Akizuki, Kazutoshi; Katayama, Syouichi; Shigeri, Yasushi; Kameshita, Isamu; Ishida, Atsuhiko; Sueyoshi, Noriyuki

    2016-07-01

    We describe here the expression and characterization of a constitutively active fragment of zebrafish Ca(2+)/calmodulin-dependent protein kinase (CaMK) Iδ designated zCaMKIδ(1-299) that lacks an autoinhibitory domain. We used a simple one-step purification method to isolate the recombinant enzyme at high yield (220 mg/l of the culture medium) from the soluble fraction of lysates prepared from Escherichia coli. Unlike the corresponding fragment of CaMKIα (CaMKΙα(1-294)), the kinase activity of zCaMKIδ(1-299), without activation procedures, was comparable to that of wild-type zCaMKIδ activated by CaMK kinase. zCaMKIδ(1-299) exhibited broad substrate specificity highly similar to that of wild-type zCaMKIδ, and complementary to that of the cAMP-dependent protein kinase catalytic subunit (PKAc). The protein kinase activity of zCaMKIδ(1-299) was higher compared with that of PKAc as well as CX-30K-CaMKII that comprises a constitutively active fragment of CaMKII fused to the N-terminal region of Xenopus CaMKI. Furthermore, kinase activity was highly stable against thermal inactivation and repeated freezing-thawing. Thus, zCaMKIδ(1-299) represents a readily available alternative that can be used as a "High-performance phosphorylating reagent" alone or in combination with PKAc in diverse experiments on protein phosphorylation and dephosphorylation. PMID:27207832

  10. The Role of Lithium Conditioning in Achieving High Performance, Long Pulse H-mode Discharges in the NSTX and EAST Devices

    SciTech Connect

    Maingi, Rajesh; Mansfield, D. K.; Gong, X. Z.; Sun, Z.; Bell, M. G.

    2014-10-01

    In this paper, the role of lithium wall conditioning on the achievement of high performance, long pulse discharges in the National Spherical Torus Experiment (NSTX) and the Experimental Advanced Superconducting Tokamak (EAST) is documented. Common observations include recycling reduction and elimination of ELMs. In NSTX, lithium conditioning typically resulted in ELM-free operation with impurity accumulation, which was ameliorated e.g. with pulsed 3D fields to trigger controlled ELMs. Active lithium conditioning in EAST discharges has overcome this problem, producing an ELM-free Hmode with controlled density and impurities.

  11. ACHIEVING NEW SOURCE PERFORMANCE STANDARDS (NSPS) EMISSION STANDARDS THROUGH INTEGRATION OF LOW-NOx BURNERS WITH AN OPTIMIZATION PLAN FOR BOILER COMBUSTION

    SciTech Connect

    Wayne Penrod; David Moyeda

    2003-04-01

    The objective of this project is to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub x} emissions levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project consists of the integration of low-NO{sub x} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The project includes the use of sophisticated neural networks or other artificial intelligence technologies and complex software that can optimize several operating parameters, including NO{sub x} emissions, boiler efficiency, and CO emissions. The program is being performed in three phases. In Phase I, the boiler is being equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler will be equipped with burner modifications designed to reduce NO{sub x} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler will be equipped with an overfire air system to permit deep reductions in NO{sub x} emissions to be achieved. Integration of the overfire air system with the improvements made in Phases I and II will permit optimization of the boiler performance, output, and emissions. During this reporting period, efforts were focused on Phase I and Phase II activities. The furnace sensors were procured and installed in February 2003. Baseline testing was performed following the sensor installation. The low-NO{sub x} burner modifications, the coal flow dampers, and the coal flow monitoring system were procured and installed during a boiler outage in March 2003. Process design activities were performed to support design of the equipment installed and to develop specifications for the overfire air system. The overfire air system preliminary engineering design was initiated.

  12. Academic Momentum at University/College: Exploring the Roles of Prior Learning, Life Experience, and Ongoing Performance in Academic Achievement across Time

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Wilson, Rachel; Liem, Gregory Arief D.; Ginns, Paul

    2014-01-01

    In the context of "academic momentum," a longitudinal study of university students (N = 904) showed high school achievement and ongoing university achievement predicted subsequent achievement through university. However, the impact of high school achievement diminished, while additive effects of ongoing university achievement continued.…

  13. The Classroom Performance System (CPS): Effects on student participation, attendance, and achievement in multicultural anatomy and physiology classes at South Texas College

    NASA Astrophysics Data System (ADS)

    Termos, Mohamad Hani

    2011-12-01

    The Classroom Performance System (CPS) is an instructional technology tool that increases student performance and addresses different learning styles. Instructional technologies are used to promote active learning; however, student embarrassment issue in a multicultural setting is not addressed. This study assessed the effect of the CPS on student participation, attendance, and achievement in multicultural college-level anatomy and physiology classes at South Texas College, where the first spoken language is not English. Quantitative method and quasi-experimental design were employed and comparative statistic methods and pre-post tests were used to collect the data. Participants were college students and sections of study were selected by convenient sampling. Participation was 100% during most of the lectures held and participation rate did not strike above 68% in control group. Attendance was significantly higher in CPS sections than the control group as shown by t-tests. Experimental sections had a higher increase in the pre-post test scores and student averages on lecture exams increased at a higher rate as compared to the control group. Therefore, the CPS increased student participation, attendance, and achievement in multicultural anatomy and physiology classes. The CPS can be studied in other settings where the first spoken language is English or in other programs, such as special education programs. Additionally, other variables can be studied and other methodologies can be employed.

  14. Simultaneous determination of albendazole and its metabolites in fish muscle tissue by stable isotope dilution ultra-performance liquid chromatography tandem mass spectrometry.

    PubMed

    Zhang, Xiaojun; Xu, Hanxiang; Zhang, Hong; Guo, Yuanming; Dai, Zhiyuan; Chen, Xuechang

    2011-08-01

    A rapid, specific, and sensitive method utilizing ultra-performance liquid chromatography tandem mass spectrometry was developed and validated to determine albendazole, albendazole sulfoxide, albendazole sulfone, and albendazole 2-aminosulfone in fish muscle tissue. The fish samples were extracted with ethyl acetate, then the organic phase was evaporated to dryness, and the residue was reconstituted in methanol-water solution and cleaned up by n-hexane. Reversed-phase separation of target compounds was achieved using a BEH C18 column and a gradient consisting of 0.2% (v/v) formic acid and methanol. Tandem mass spectrometry analyses were performed on a triple-quadrupole tandem mass spectrometer. In the whole procedure, the isotope-labeled internal standards were used to correct the matrix effect and variations associated with the analysis. The method was validated with respect to linearity, specificity, accuracy, and precision. The method exhibited a linear response from 0.1 to 20 ng mL(-1) (r(2) > 0.9985). The limit of quantitation for albendazole (ABZ), albendazole sulfoxide (ABZSO), albendazole sulfone (ABZSO(2)), and albendazole 2-aminosulfone (ABZ-2-NH(2)SO(2)) was 0.1, 0.1, 0.1, and 0.2 ng g(-1), respectively. The mean recoveries of ABZ, ABZSO, ABZSO(2), and ABZ-2-NH(2)SO(2) spiked at a level of 0.2-5.0 ng g(-1) were 95.3-113.7%, and the relative standard deviations of intra- and inter-day measurements were less than 6.38%. The method was later successfully applied to the determination of albendazole and its three metabolites in 60 fish samples collected from local markets. PMID:21633840

  15. Measurement of Niacin in a Variety of Food Samples by High Performance Liquid Chromatography-Stable Isotope Dilution Mass Spectrometry (AOAC Annual Meeting, Minneapolis, MN, Sept. 2006)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectrometry (SIDMS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin, niacin, in food samples. We have developed a method based on AOAC Peer-Verif...

  16. Measurement of Niacin in a Variety of Food Samples by High Performance Liquid Chromatography-Stable Isotope Dilution Mass Spectrometry (Experimental Biology, April, 2007, Washington, D.C.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectrometry (SIDMS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin, niacin, in food samples. We have developed a method based on AOAC Peer-Verif...

  17. Hygrothermally stable laminated composites with optimal coupling

    NASA Astrophysics Data System (ADS)

    Haynes, Robert Andrew

    This work begins by establishing the necessary and sufficient conditions for hygrothermal stability of composite laminates. An investigation is performed into the range of coupling achievable from within all hygrothermally stable families. The minimum number of plies required to create an asymmetric hygrothermally stable stacking sequence is found to be five. Next, a rigorous and general approach for determining designs corresponding to optimal levels of coupling is established through the use of a constrained optimization procedure. Couplings investigated include extension-twist, bend-twist, extension-bend, shear-twist, and anticlastic. For extension-twist and bend-twist coupling, specimens from five- through ten-ply laminates are manufactured and tested to demonstrate hygrothermal stability and achievable levels of coupling. Nonlinear models and finite element analysis are developed, and predictions are verified through comparison with test results. Sensitivity analyses are performed to demonstrate the robustness of the hygrothermal stability and couplings to deviations in ply angle, typical of manufacturing tolerances. Comparisons are made with current state-of-the-art suboptimal layups, and significant increases in coupling over previously known levels are demonstrated.

  18. Attractiveness and School Achievement

    ERIC Educational Resources Information Center

    Salvia, John; And Others

    1977-01-01

    The purpose of this study was to ascertain the relationship between rated attractiveness and two measures of school performance. Attractive children received significantly higher report cards and, to some degree, higher achievement test scores than their unattractive peers. (Author)

  19. The impact of nursing students' chemistry learning performance assessment in Taiwan: competitive versus non-competitive student team achievement division approaches

    NASA Astrophysics Data System (ADS)

    Wang, Kai-Ping

    2012-07-01

    Purpose: The purpose of this study was to determine the effectiveness of competitive Student Team Achievement Division (STAD), non-competitive STAD, and traditional learning on chemistry learning and learning perceptions. Sample, design and methods: By adopting the STAD approach, this study examined 144 nursing students at a five-year junior college in northern Taiwan during the first semester (totaling 18 weeks) of the 2008 academic year. Results: The findings reveal that both a heterogeneous group with external pressure (involving competitive STAD) and a friendship group with affective pressure (involving traditional learning) enhance group cohesion and assist students' meaningful learning; the heterogeneous group without extra pressure (involving non-competitive STAD), by contrast, fails because of apathy and lassitude. Moreover, learning effectiveness will obviously predominate until the learning strategy continues for a long period or at least one semester. Conclusions: This study revealed that the learning performance level of the competitive STAD group is significantly different from that of the non-competitive STAD group; and the learning performance level of the traditional group is significantly different from that of the non-competitive STAD group. Both the competitive STAD group and traditional group of medium ability students are significantly different from the non-competitive STAD group. Low-ability students from the competitive STAD group are significantly different from those of the non-competitive STAD, though no significant differences were found in learning perception. However, both a lack of friendship and a lack of ability in using algorithms may affect students' chemistry learning. Furthermore, gender imbalance, educational culture, and group emotions are factors that may influence student learning performance. Further study should focus on the use of grouping, improve responsibility in group discussion, and investigate group interaction

  20. Achieving highly effective non-biofouling performance for polypropylene membranes modified by UV-induced surface graft polymerization of two oppositely charged monomers.

    PubMed

    Zhao, Yong-Hong; Zhu, Xiao-Ying; Wee, Kin-Ho; Bai, Renbi

    2010-02-25

    A major problem in membrane technology for applications such as wastewater treatment or desalination is often the loss of membrane permeability due to biofouling initiated from protein adsorption and biofilm formation on the membrane surface. In this study, we developed a relatively simple and yet versatile approach to prepare polypropylene (PP) membrane with highly effective non-biofouling performance. Copolymer brushes were grafted to the surface of PP membrane through UV-induced polymerization of two oppositely charged monomers, i.e., [2-(methacryloyloxy)ethyl]trimethylammonium chloride (TM) and 3-sulfopropyl methacrylate potassium salt (SA), with varying TM:SA molar ratios. Surface analysis with scanning electron microscope (SEM) clearly showed the grafted copolymer brushes on the membrane surfaces and that with X-ray photoelectron spectroscope (XPS) revealed a similar TM:SA ratio of the grafted copolymer brushes to that of the monomer solution used for the polymerization. Water contact angle measurements indicated that the hydrophilicity of the membrane surfaces was remarkably improved by the grafting of the TM/SA copolymer brushes, with the lowest water contact angle of 27 degrees being achieved at the TM:SA ratio of around 1:1. Experiments for antiprotein adsorption with bovine serum album (BSA) and lysozyme (LYZ) and antibiofilm formation with Escherichia coli (E. coli) demonstrated a great dependence of the membrane performance on the TM:SA ratios of the grafted copolymer brushes. It was found that the characteristics of the surface charges of the membrane surfaces played a very important role in the non-biofouling performance, and the membrane surface with balanced positive and negative charges showed the best non-biofouling performance for the proteins and bacteria tested in this study. PMID:20121056

  1. Multi-stable cylindrical lattices

    NASA Astrophysics Data System (ADS)

    Pirrera, Alberto; Lachenal, Xavier; Daynes, Stephen; Weaver, Paul M.; Chenchiah, Isaac V.

    2013-11-01

    We present a cylindrical lattice structure that mimics the behaviour of the virus bacteriophage T4 in having two (or more) stable states which differ in their radii and length. While the virus achieves bistability through molecular mechanisms we use composite materials to exploit the interplay between pre-stress, material properties and structural geometry. We demonstrate (computationally) that multi-stability is a robust phenomenon. We also show (analytically) that it is possible to choose the design variables so that the energy is independent of the radius, thus resulting in every state of the structure being stable.

  2. An investigation of signal performance enhancements achieved through innovative pixel design across several generations of indirect detection, active matrix, flat-panel arrays

    SciTech Connect

    Antonuk, Larry E.; Zhao Qihua; El-Mohri, Youcef; Du Hong; Wang Yi; Street, Robert A.; Ho, Jackson; Weisfield, Richard; Yao, William

    2009-07-15

    Active matrix flat-panel imager (AMFPI) technology is being employed for an increasing variety of imaging applications. An important element in the adoption of this technology has been significant ongoing improvements in optical signal collection achieved through innovations in indirect detection array pixel design. Such improvements have a particularly beneficial effect on performance in applications involving low exposures and/or high spatial frequencies, where detective quantum efficiency is strongly reduced due to the relatively high level of additive electronic noise compared to signal levels of AMFPI devices. In this article, an examination of various signal properties, as determined through measurements and calculations related to novel array designs, is reported in the context of the evolution of AMFPI pixel design. For these studies, dark, optical, and radiation signal measurements were performed on prototype imagers incorporating a variety of increasingly sophisticated array designs, with pixel pitches ranging from 75 to 127 {mu}m. For each design, detailed measurements of fundamental pixel-level properties conducted under radiographic and fluoroscopic operating conditions are reported and the results are compared. A series of 127 {mu}m pitch arrays employing discrete photodiodes culminated in a novel design providing an optical fill factor of {approx}80% (thereby assuring improved x-ray sensitivity), and demonstrating low dark current, very low charge trapping and charge release, and a large range of linear signal response. In two of the designs having 75 and 90 {mu}m pitches, a novel continuous photodiode structure was found to provide fill factors that approach the theoretical maximum of 100%. Both sets of novel designs achieved large fill factors by employing architectures in which some, or all of the photodiode structure was elevated above the plane of the pixel addressing transistor. Generally, enhancement of the fill factor in either discrete or

  3. An investigation of signal performance enhancements achieved through innovative pixel design across several generations of indirect detection, active matrix, flat-panel arrays

    PubMed Central

    Antonuk, Larry E.; Zhao, Qihua; El-Mohri, Youcef; Du, Hong; Wang, Yi; Street, Robert A.; Ho, Jackson; Weisfield, Richard; Yao, William

    2009-01-01

    Active matrix flat-panel imager (AMFPI) technology is being employed for an increasing variety of imaging applications. An important element in the adoption of this technology has been significant ongoing improvements in optical signal collection achieved through innovations in indirect detection array pixel design. Such improvements have a particularly beneficial effect on performance in applications involving low exposures and∕or high spatial frequencies, where detective quantum efficiency is strongly reduced due to the relatively high level of additive electronic noise compared to signal levels of AMFPI devices. In this article, an examination of various signal properties, as determined through measurements and calculations related to novel array designs, is reported in the context of the evolution of AMFPI pixel design. For these studies, dark, optical, and radiation signal measurements were performed on prototype imagers incorporating a variety of increasingly sophisticated array designs, with pixel pitches ranging from 75 to 127 μm. For each design, detailed measurements of fundamental pixel-level properties conducted under radiographic and fluoroscopic operating conditions are reported and the results are compared. A series of 127 μm pitch arrays employing discrete photodiodes culminated in a novel design providing an optical fill factor of ∼80% (thereby assuring improved x-ray sensitivity), and demonstrating low dark current, very low charge trapping and charge release, and a large range of linear signal response. In two of the designs having 75 and 90 μm pitches, a novel continuous photodiode structure was found to provide fill factors that approach the theoretical maximum of 100%. Both sets of novel designs achieved large fill factors by employing architectures in which some, or all of the photodiode structure was elevated above the plane of the pixel addressing transistor. Generally, enhancement of the fill factor in either discrete or continuous

  4. The Value of Extracurricular Support in Increased Student Achievement: An Assessment of a Pupil Personnel Model Including School Counselors and School Psychologists Concerning Student Achievement as Measured by an Academic Performance Index

    ERIC Educational Resources Information Center

    Goodman, Greg S.; Young, I. Phillip

    2006-01-01

    This study examined two models of extra-curricular support for enhancing the academic achievement of students as measured by state mandated test scores. One management model includes the use of school counselors as enhancers of the educational process while the other model addresses the contribution of school psychologists. To differentiate…

  5. Achieving extremely concentrated aqueous dispersions of graphene flakes and catalytically efficient graphene-metal nanoparticle hybrids with flavin mononucleotide as a high-performance stabilizer.

    PubMed

    Ayán-Varela, M; Paredes, J I; Guardia, L; Villar-Rodil, S; Munuera, J M; Díaz-González, M; Fernández-Sánchez, C; Martínez-Alonso, A; Tascón, J M D

    2015-05-20

    The stable dispersion of graphene flakes in an aqueous medium is highly desirable for the development of materials based on this two-dimensional carbon structure, but current production protocols that make use of a number of surfactants typically suffer from limitations regarding graphene concentration or the amount of surfactant required to colloidally stabilize the sheets. Here, we demonstrate that an innocuous and readily available derivative of vitamin B2, namely the sodium salt of flavin mononucleotide (FMNS), is a highly efficient dispersant in the preparation of aqueous dispersions of defect-free, few-layer graphene flakes. Most notably, graphene concentrations in water as high as ∼50 mg mL(-1) using low amounts of FMNS (FMNS/graphene mass ratios of about 0.04) could be attained, which facilitated the formation of free-standing graphene films displaying high electrical conductivity (∼52000 S m(-1)) without the need of carrying out thermal annealing or other types of post-treatment. The excellent performance of FMNS as a graphene dispersant could be attributed to the combined effect of strong adsorption on the sheets through the isoalloxazine moiety of the molecule and efficient colloidal stabilization provided by its negatively charged phosphate group. The FMNS-stabilized graphene sheets could be decorated with nanoparticles of several noble metals (Ag, Pd, and Pt), and the resulting hybrids exhibited a high catalytic activity in the reduction of nitroarenes and electroreduction of oxygen. Overall, the present results should expedite the processing and implementation of graphene in, e.g., conductive inks, composites, and hybrid materials with practical utility in a wide range of applications. PMID:25915172

  6. Stable Fly Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult stable flies feed on the blood of humans, pets and livestock, inflicting painful bites. Stable flies need one and sometimes two bloodmeals each day to develop their eggs. Unlike mosquitoes where only the females bloodfeed, both male and female stable flies require blood to reproduce. Stable fl...

  7. Stable predictive control horizons

    NASA Astrophysics Data System (ADS)

    Estrada, Raúl; Favela, Antonio; Raimondi, Angelo; Nevado, Antonio; Requena, Ricardo; Beltrán-Carbajal, Francisco

    2012-04-01

    The stability theory of predictive and adaptive predictive control for processes of linear and stable nature is based on the hypothesis of a physically realisable driving desired trajectory (DDT). The formal theoretical verification of this hypothesis is trivial for processes with a stable inverse, but it is not for processes with an unstable inverse. The extended strategy of predictive control was developed with the purpose of overcoming methodologically this stability problem and it has delivered excellent performance and stability in its industrial applications given a suitable choice of the prediction horizon. From a theoretical point of view, the existence of a prediction horizon capable of ensuring stability for processes with an unstable inverse was proven in the literature. However, no analytical solution has been found for the determination of the prediction horizon values which guarantee stability, in spite of the theoretical and practical interest of this matter. This article presents a new method able to determine the set of prediction horizon values which ensure stability under the extended predictive control strategy formulation and a particular performance criterion for the design of the DDT generically used in many industrial applications. The practical application of this method is illustrated by means of simulation examples.

  8. An analysis of factors correlated with the achievement of the goal standard for the science portion of the Connecticut Academic Performance Test

    NASA Astrophysics Data System (ADS)

    Kmetz, Barbara Fotta

    2001-07-01

    This study sought to identify factors that could be used to predict the success of students on the science portion of the grade ten Connecticut Academic Performance Test (CAPT). While the Connecticut State Department of Education measures student achievement in mathematics, reading and writing in grades 4, 6, and 8, science is assessed only in the grade ten CAPT. Since the CAPT science test does not identify specific areas in need of improvement, it is not possible to determine causes for low test scores. To address this, the study investigated the predictive values of the grade eight Mastery Tests in mathematics and reading, the student ability scores of the Otis-Lennon School Ability Index, and grades in prior science courses. The research sample consisted of five hundred and twenty-five students, member of the graduating classes of 2000 and 2001 in a large suburban high school. Students in the study had participated in the district testing program and their scores for the grade seven Otis-Lennon School Ability Test (OLSAT), the grade eight Connecticut Mastery Tests (CMT) and the grade ten Connecticut Academic Performance Tests (CAPT) were available for analysis. This study investigated correlations between student achievement on the CMT and the science subtest of the CAPT, between OLSAT scores and the CAPT science scores, and between grades in ninth grade science and CAPT science scores. Scores were disaggregated by gender and by course level. Hypotheses 1, 2, 3 and 4 investigated the Pearson Product Moment Correlations of the OLSAT, CMT and course grades with scores on the science portion of the CAPT. Hypothesis 5 compared the scores of male and female students, using the t-test of independent sample means. Calculations showed moderate correlations for hypotheses 1--4, and the hypotheses were accepted. Hypothesis 5 was accepted for one class and rejected for the other. On the whole, female students received higher course grades and lower standardized test

  9. Simple, stable and sensitive electrogenerated chemiluminescence detector for high-performance liquid chromatography and its application in direct determination of multiple fluoroquinolone residues in milk.

    PubMed

    Li, Yongbo; Zhang, Zhujun; Li, Jinsong; Li, Hongguang; Chen, Yan; Liu, Zhaohui

    2011-05-15

    A simple, stable and sensitive electrogenerated chemiluminescence (ECL) detector was developed. It was based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) immobilized on the surface of a Pt wire with Nepem-105D ion exchange solution. The detector was prepared by inserting a Pt wire with immobilized Ru(bpy)(3)(2+) (working electrode) into a capillary tube, followed by inserting another Pt wire (counter electrode) in this tube and sealing. ECL behavior was investigated using ofloxacin as an analyte. Under optimal conditions, stable ECL intensity was obtained. This detector has been used in HPLC-ECL for the determination of multiple target fluoroquinolone residues in milk. There is no post column reagent addition, which would dilute the analytes, potentially leading to chromatographic band-broadening. The system is very simple with low dead volume, low baseline and background noise, together with high sensitivity and stability. The as-prepared ECL detector, when was used for the determination of ofloxacin, pefloxacin, enrofloxacin and difloxacin in milk, demonstrated adequate sensitivity to allow quantification of trace FQ levels in commercial milk samples. One or more of the target FQ analytes were present at levels above the LOD of the new ECL detector in each and every one of the 22 milk samples analysed. PMID:21482269

  10. Stable topological insulators achieved using high energy electron beams

    PubMed Central

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  11. Stable topological insulators achieved using high energy electron beams

    NASA Astrophysics Data System (ADS)

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-03-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (~2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.

  12. Stable topological insulators achieved using high energy electron beams.

    PubMed

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  13. Activities on Realization of High-Power and Steady-State ECRH System and Achievement of High Performance Plasmas in LHD

    SciTech Connect

    Shimozuma, T.; Kubo, S.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Ikeda, R.; Tamura, N.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Takita, Y.; Mutoh, T.; Minami, R.; Kariya, T.; Imai, T.; Idei, H.; Shapiro, M. A.; Temkin, R. J.; Felici, F.; Goodman, T.

    2009-11-26

    Electron Cyclotron Resonance Heating (ECRH) has contributed to the achievement of high performance plasma production, high electron temperature plasmas and sustainment of steady-state plasmas in the Large Helical Device (LHD). Our immediate targets of upgrading the ECRH system are 5 MW several seconds and 1 MW longer than one hour power injection into LHD. The improvement will greatly extend the plasma parameter regime. For that purpose, we have been promoting the development and installation of 77 GHz/1-1.5 MW/several seconds and 0.3 MW/CW gyrotrons in collaboration with University of Tsukuba. The transmission lines are re-examined and improved for high and CW power transmission. In the recent experimental campaign, two 77 GHz gyrotrons were operated. One more gyrotron, which was designed for 1.5 MW/2 s output, was constructed and is tested. We have been promoting to improve total ECRH efficiency for efficient gyrotron-power use and efficient plasma heating, e.g. a new waveguide alignment method and mode-content analysis and the feedback control of the injection polarization. In the last experimental campaign, the 77 GHz gyrotrons were used in combination with the existing 84 GHz range and 168 GHz gyrotrons. Multi-frequency ECRH system is more flexible in plasma heating experiments and diagnostics. A lot of experiments have been performed in relation to high electron temperature plasmas by realization of the core electron-root confinement (CERC), electron cyclotron current drive (ECCD), Electron Bernstein Wave heating, and steady-state plasma sustainment. Some of the experimental results are briefly described.

  14. Achieving New Source Performance Standards (NSPS) Emission Standards Through Integration of Low-NOx Burners with an Optimization Plan for Boiler Combustion

    SciTech Connect

    Wayne Penrod

    2006-12-31

    The objective of this project was to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub X} emission levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project plan consisted of the integration of low-NO{sub X} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The plan included the use of sophisticated neural networks or other artificial intelligence technologies and complex software to optimize several operating parameters, including NO{sub X} emissions, boiler efficiency, and CO emissions. The program was set up in three phases. In Phase I, the boiler was equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler was equipped with burner modifications designed to reduce NO{sub X} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler was to be equipped with an overfire air system to permit deep reductions in NO{sub X} emissions. Integration of the overfire air system with the improvements made in Phases I and II would permit optimization of boiler performance, output, and emissions. This report summarizes the overall results from Phases I and II of the project. A significant amount of data was collected from the combustion sensors, coal flow monitoring equipment, and other existing boiler instrumentation to monitor performance of the burner modifications and the coal flow balancing equipment.

  15. Magnetotelluric Data, Stable Distributions and Stable Regression

    NASA Astrophysics Data System (ADS)

    Chave, A. D.

    2013-12-01

    The author has noted for many years that the residuals from robust or bounded influence estimates of the magnetotelluric response function are systematically long tailed compared to a Gaussian or Rayleigh distribution. Consequently, the standard statistical model of a Gaussian core contaminated by a fraction of outlying data is not really valid. However, the typical result is an improvement on ordinary least squares, and has become standard in the electromagnetic induction community. A recent re-evaluation of the statistics of magnetotelluric response function estimation has shown that, in almost all cases, the residuals are alpha stable rather than Gaussian. Alpha stable distributions are characterized by four parameters: a shape parameter lying on (0, 2], a skewness parameter, a scale parameter and a location parameter, and cannot be expressed in closed form except for a few special cases. When the shape parameter is 2, the result is Gaussian, but when it is smaller the resulting distribution has infinite variance. Typical magnetotelluric residuals are alpha stable with a shape parameter lying between 1 and 2. This suggests that robust methods improve response function estimates by eliminating data corresponding to the largest stable residuals while leaving the bulk of the population alone. A better statistical approach is based on stable regression that directly accommodates the actual residual distribution without eliminating the most extreme ones. This paper will introduce such an algorithm, and illustrate its functionality with a variety of magnetotelluric data. Further work remains to produce a robust stable regression algorithm that will eliminate real outliers such as lightning strikes or instrument problems without affecting the bulk stable population. Stable distributions are intimately associated with fractional derivative physical processes. Since the Maxwell equations and the constitutive relations pertaining to the earth do not contain any fractional

  16. Is preschool executive function causally related to academic achievement?

    PubMed

    Willoughby, Michael T; Kupersmidt, Janis B; Voegler-Lee, Mary E

    2012-01-01

    The primary objective of this study was to reevaluate the well-established result that preschoolers' performance on executive function tasks are positively associated with their performance on academic achievement tests. The current study replicated the previously established concurrent associations between children's performance on EF tasks and academic achievement tests. Specifically, children's performance on measures of inhibitory and motor control were positively associated with their performance on tests of reading, writing, and mathematics achievement (rs = .2-.5); moreover, although diminished in magnitude, most of these associations held up even after including an earlier measure of academic achievement as a covariate (rs = .1-.3). However, the application of an alternative analytic method, fixed effects analysis, a method that capitalizes on repeated measures data to control for all time stable measured and unmeasured covariates, rendered the apparent positive associations between executive function and academic achievement nonsignificant (rs = .0-.1). Taken together, these results suggest that the well-replicated association between executive function abilities and academic achievement may be spurious. Results are discussed with respect to the importance of utilizing analytic methods and research designs that facilitate strong causal inferences between executive function and academic achievement in early childhood, as well as the limitations of making curriculum development recommendations and/or public policy decisions based on studies that have failed to do so. PMID:21707258

  17. Angina Pectoris (Stable Angina)

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Angina Pectoris (Stable Angina) Updated:Aug 24,2016 You may have heard the term “angina pectoris” or “stable angina” in your doctor’s office, but ...

  18. The Predictability of Enrolment and First-Year University Results from Secondary School Performance: The New Zealand National Certificate of Educational Achievement

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Hattie, John; Tumen, Sarah

    2008-01-01

    This study investigates the predictive correlations between results from the New Zealand National Certificate of Educational Achievement (NCEA), a standards-based qualification, and university grade point averages achieved by first-year students in one large New Zealand University (and, for comparison purposes, also presents correlations from the…

  19. Synchronously Achieving Plasmonic Bi Metal Deposition and I(-) Doping by Utilizing BiOIO3 as the Self-Sacrificing Template for High-Performance Multifunctional Applications.

    PubMed

    Yu, Shixin; Huang, Hongwei; Dong, Fan; Li, Min; Tian, Na; Zhang, Tierui; Zhang, Yihe

    2015-12-23

    Herein, we uncover simultaneously achieving plasmonic Bi metal deposition and I(-) doping by employing wide-band-gap BiOIO3 as the self-sacrificing template. It was synthesized via a facile NaBH4-assisted in situ reduction route under ambient conditions. The reducing extent as well as photocatalytic levels can be easily modulated by controlling the concentration of NaBH4 solution. It is interesting that the band gap of BiOIO3 can be continuously narrowed by the modification, and the photoresponse range is drastically extended to cover the whole visible region. Bi/I(-) codecorated BiOIO3 not only exhibits profoundly upgraded photoreactivity in comparison with pristine BiOIO3 but also shows universally strong photooxidation properties toward decomposition of multiple industrial contaminants and pharmaceutical, including phenol, 2,4-Dichlorophenol (2,4-DCP), bisphenol A (BPA), dye model Rhodamine (RhB), tetracycline hydrochloride, and gaseous NO under visible light (λ ≥ 420 nm) or simulated solar light irradiation. It also outperforms the well-known and important photocatalysts C3N4, BiOBr, and Bi2WO6 for NO removal. The cooperative effects from Bi SPR and I(-) doping endow BiOIO3 with a narrowed band gap and highly boosted separation of charge carriers, thus responsible for the outstanding catalytic activity. The present study provides an absorbing candidate for practical environmental applications and also furthers our understanding of developing high-performance photocatalysts by manipulating manifold strategies in a facile way. PMID:26605639

  20. Stable electroosmotically driven actuators

    NASA Astrophysics Data System (ADS)

    Sritharan, Deepa; Motsebo, Mylene; Tumbic, Julia; Smela, Elisabeth

    2013-04-01

    We have previously presented "nastic" actuators based on electroosmotic (EO) pumping of fluid in microchannels using high electric fields for potential application in soft robotics. In this work we address two challenges facing this technology: applying EO to meso-scale devices and the stability of the pumping fluid. The hydraulic pressure achieved by EO increases with as 1/d2, where d is the depth of the microchannel, but the flow rate (which determines the stroke and the speed) is proportional to nd, where n is the number of channels. Therefore to get high force and high stroke the device requires a large number of narrow channels, which is not readily achievable using standard microfabrication techniques. Furthermore, for soft robotics the structure must be soft. In this work we present a method of fabricating a three-dimensional porous elastomer to serve as the array of channels based on a sacrificial sugar scaffold. We demonstrate the concept by fabricating small pumps. The flexible devices were made from polydimethylsiloxane (PDMS) and comprise the 3D porous elastomer flanked on either side by reservoirs containing electrodes. The second issue addressed here involves the pumping fluid. Typically, water is used for EO, but water undergoes electrolysis even at low voltages. Since EO takes place at kV, these systems must be open to release the gases. We have recently reported that propylene carbonate (PC) is pumped at a comparable rate as water and is also stable for over 30 min at 8 kV. Here we show that PC is, however, degraded by moisture, so future EO systems must prevent water from reaching the PC.

  1. High-performance and environmentally stable planar heterojunction perovskite solar cells based on a solution-processed copper-doped nickel oxide hole-transporting layer.

    PubMed

    Kim, Jong H; Liang, Po-Wei; Williams, Spencer T; Cho, Namchul; Chueh, Chu-Chen; Glaz, Micah S; Ginger, David S; Jen, Alex K-Y

    2015-01-27

    An effective approach to significantly increase the electrical conductivity of a NiOx hole-transporting layer (HTL) to achieve high-efficiency planar heterojunction perovskite solar cells is demonstrated. Perovskite solar cells based on using Cu-doped NiOx HTL show a remarkably improved power conversion efficiency up to 15.40% due to the improved electrical conductivity and enhanced perovskite film quality. General applicability of Cu-doped NiOx to larger bandgap perovskites is also demonstrated in this study. PMID:25449020

  2. Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers.

    PubMed

    Kim, Sok; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-08-01

    Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28±13.15mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume. PMID:27045623

  3. SrCo(0.9)Ti(0.1)O(3-δ) As a New Electrocatalyst for the Oxygen Evolution Reaction in Alkaline Electrolyte with Stable Performance.

    PubMed

    Su, Chao; Wang, Wei; Chen, Yubo; Yang, Guangming; Xu, Xiaomin; Tadé, Moses O; Shao, Zongping

    2015-08-19

    The development of efficient, inexpensive, and stable electrocatalysts for the oxygen evolution reaction (OER) is critical for many electrochemical energy conversion technologies. The prohibitive price and insufficient stability of the state-of-the-art IrO2 electrocatalyst for the OER inhibits its use in practical devices. Here, SrM0.9Ti0.1O3-δ (M = Co, Fe) perovskites with different B-site transition metal elements were investigated as potentially cheaper OER electrocatalysts. They were prepared through a typical sol-gel route, and their catalytic activities for the OER in alkaline medium were comparatively studied using rotating disk electrodes. Both materials show high initial intrinsic activities in alkaline electrolyte for the OER, comparable to the benchmark perovskite-type electrocatalyst Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), but SrCo0.9Ti0.1O3-δ (SCT) possessed more operational stability than SrFe0.9Ti0.1O3-δ (SFT), even better than BSCF and IrO2 catalysts. Based on the X-ray photoelectron spectra analysis of the oxidation states of the surface Co/Fe in both SFT and SCT before and after the OER tests, an explanation for their different operational stabilities was proposed by adopting a reported activity descriptor correlated to the eg occupancy of the 3d electron of the surface transition metal cations in the perovskite oxides. The above results indicate that SCT is a promising alternative electrocatalyst for the OER and can be used in electrochemical devices for water oxidation. PMID:26222739

  4. Diagnosing coronary artery disease by sound analysis from coronary stenosis induced turbulent blood flow: diagnostic performance in patients with stable angina pectoris.

    PubMed

    Winther, Simon; Schmidt, Samuel Emil; Holm, Niels Ramsing; Toft, Egon; Struijk, Johannes Jan; Bøtker, Hans Erik; Bøttcher, Morten

    2016-02-01

    Optimizing risk assessment may reduce use of advanced diagnostic testing in patients with symptoms suggestive of stable coronary artery disease (CAD). Detection of diastolic murmurs from post-stenotic coronary turbulence with an acoustic sensor placed on the chest wall can serve as an easy, safe, and low-cost supplement to assist in the diagnosis of CAD. The aim of this study was to evaluate the diagnostic accuracy of an acoustic test (CAD-score) to detect CAD and compare it to clinical risk stratification and coronary artery calcium score (CACS). We prospectively enrolled patients with symptoms of CAD referred to either coronary computed tomography or invasive coronary angiography (ICA). All patients were tested with the CAD-score system. Obstructive CAD was defined as more than 50 % diameter stenosis diagnosed by quantitative analysis of the ICA. In total, 255 patients were included and obstructive CAD was diagnosed in 63 patients (28 %). Diagnostic accuracy evaluated by receiver operating characteristic curves was 72 % for the CAD-score, which was similar to the Diamond-Forrester clinical risk stratification score, 79 % (p = 0.12), but lower than CACS, 86 % (p < 0.01). Combining the CAD-score and Diamond-Forrester score, AUC increased to 82 %, which was significantly higher than the standalone CAD-score (p < 0.01) and Diamond-Forrester score (p < 0.05). Addition of the CAD-score to the Diamond-Forrester score increased correct reclassification, categorical net-reclassification index = 0.31 (p < 0.01). This study demonstrates the potential use of an acoustic system to identify CAD. The combination of clinical risk scores and an acoustic test seems to optimize patient selection for diagnostic investigation. PMID:26335368

  5. [Determination of L-dopa and dopamine in rat brain microdialysate by ultra high performance liquid chromatography-tandem mass spectrometry using stable isotope-coded derivatization coupled with dispersive liquid-liquid microextraction].

    PubMed

    Qi, Weimei; Zhao, Xian-en; Qi, Yong; Sun, Zhiwei; Chen, Guang; You, Jinmao; Suo, Yourui

    2015-09-01

    The sensitive detection method of levodopa (L-DOPA) and dopamine (DA) in rat brain microdialysate of Parkinson's disease (PD) is an essential tool for the clinical study and attenuated synergistic drug screening for L-DOPA from traditional Chinese medicines. Using d0/d3-10-methyl-acridone-2-sulfonyl chloride (d0/d3-MASC) as stable isotope derivatization reagent, a novel ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for L-DOPA and DA by stable isotope- coded derivatization coupled with ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME). d3-MASC (light) and d3-MASC (heavy) were used as derivatization reagents for microdialysate samples and standards, respectively. Mixtures of the two solutions were prepared by UA-DLLME for UHPLC-MS/MS analysis with multiple reaction monitoring (MRM) mode. With d3-MASC heavy derivatives as internal standards for corresponding light derivatives from samples, the stable isotope internal standard quantification for L-DOPA and DA was carried out. The stable derivatives were obtained in aqueous acetonitrile (pH 10.8 sodium carbonate-sodium bicarbonate buffer) at 37 °C for 3.0 min, and then were separated within 2.0 min using gradient elution. Linear range was 0.20-1500.0 nmol/L (R > 0.994). LODs were 0.005 and 0.009 nmol/L for DA and L-DOPA (S/N = 3), respectively. This method was validated, and it showed obvious advantages in comparing with the reported methods in terms of sensitivity, analysis speed and anti-matrix interference. This method has been successfully applied to the study of effect of Shouwu Fang on L-DOPA and DA concentration fluctuations in PD rat brain microdialysate. PMID:26753287

  6. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  7. Increasing Male Academic Achievement

    ERIC Educational Resources Information Center

    Jackson, Barbara Talbert

    2008-01-01

    The No Child Left Behind legislation has brought greater attention to the academic performance of American youth. Its emphasis on student achievement requires a closer analysis of assessment data by school districts. To address the findings, educators must seek strategies to remedy failing results. In a mid-Atlantic district of the Unites States,…

  8. Stable face representations

    PubMed Central

    Jenkins, Rob; Burton, A. Mike

    2011-01-01

    Photographs are often used to establish the identity of an individual or to verify that they are who they claim to be. Yet, recent research shows that it is surprisingly difficult to match a photo to a face. Neither humans nor machines can perform this task reliably. Although human perceivers are good at matching familiar faces, performance with unfamiliar faces is strikingly poor. The situation is no better for automatic face recognition systems. In practical settings, automatic systems have been consistently disappointing. In this review, we suggest that failure to distinguish between familiar and unfamiliar face processing has led to unrealistic expectations about face identification in applied settings. We also argue that a photograph is not necessarily a reliable indicator of facial appearance, and develop our proposal that summary statistics can provide more stable face representations. In particular, we show that image averaging stabilizes facial appearance by diluting aspects of the image that vary between snapshots of the same person. We review evidence that the resulting images can outperform photographs in both behavioural experiments and computer simulations, and outline promising directions for future research. PMID:21536553

  9. Students' Accounts of School-Performance Stress: A Qualitative Analysis of a High-Achieving Setting in Stockholm, Sweden

    ERIC Educational Resources Information Center

    Låftman, Sara Brolin; Almquist, Ylva B.; Östberg, Viveca

    2013-01-01

    The aim of the study is to examine students' experiences of school performance as a stressor. Accounts of school-performance stress at both the individual level and in relation to group mechanisms are studied through qualitative interviews with eighth-grade students in a high-performing school in Stockholm, Sweden (n = 49). Using qualitative…

  10. Achieving Professional Excellence: Proceedings of a National Conference on Performance-Based Approaches to Training (Little Rock, Arkansas, October 8-10, 1985).

    ERIC Educational Resources Information Center

    Harrington, Lois G., Comp.; Kalamas, David J., Comp.

    This document contains 47 presentations which focus on professional preparation of personnel in vocational-technical education and industry as an essential step in achieving excellence in educational and industrial training programs. The presentations include "Critical Issues Facing Vocational Teacher Education" (Zellner, Parrish); "A Call for…

  11. Beating the Odds II: A City-By-City Analysis of Student Performance and Achievement Gaps on State Assessments, Spring 2001 Results.

    ERIC Educational Resources Information Center

    Casserly, Michael

    This report presents district-by-district achievement data on 57 major city school systems in reading and mathematics. State assessment results were collected from state Web sites, reports, and databases. Data were analyzed by race/ethnicity when reported. Overall, the Great City Schools have made meaningful gains in math scores on state…

  12. The Impact of Nursing Students' Chemistry Learning Performance Assessment in Taiwan: Competitive versus Non-Competitive Student Team Achievement Division Approaches

    ERIC Educational Resources Information Center

    Wang, Kai-Ping

    2012-01-01

    Purpose: The purpose of this study was to determine the effectiveness of competitive Student Team Achievement Division (STAD), non-competitive STAD, and traditional learning on chemistry learning and learning perceptions. Sample, design and methods: By adopting the STAD approach, this study examined 144 nursing students at a five-year junior…

  13. Are Physical Activity and Academic Performance Compatible? Academic Achievement, Conduct, Physical Activity and Self-Esteem of Hong Kong Chinese Primary School Children

    ERIC Educational Resources Information Center

    Yu, C. C. W.; Chan, Scarlet; Cheng, Frances; Sung, R. Y. T.; Hau, Kit-Tai

    2006-01-01

    Education is so strongly emphasized in the Chinese culture that academic success is widely regarded as the only indicator of success, while too much physical activity is often discouraged because it drains energy and affects academic concentration. This study investigated the relations among academic achievement, self-esteem, school conduct and…

  14. Autonomy Support and Achievement Goals as Predictors of Perceived School Performance and Life Satisfaction in the Transition between Lower and Upper Secondary School

    ERIC Educational Resources Information Center

    Diseth, Åge; Samdal, Oddrun

    2014-01-01

    A self-determination theory perspective on motivation assumes that basic need support is a prerequisite for motivation, achievement, and well-being in several domains of life. In the present cross-sectional study, a representative sample of 2.594 Norwegian students in their final year of lower secondary education and their first year of upper…

  15. Feelings and Performance in the First Year at University: Learning-Related Emotions as Predictors of Achievement Outcomes in Mathematics and Statistics

    ERIC Educational Resources Information Center

    Niculescu, Alexandra C.; Templelaar, Dirk; Leppink, Jimmie; Dailey-Hebert, Amber; Segers, Mien; Gijselaers, Wim

    2015-01-01

    Introduction: This study examined the predictive value of four learning-related emotions--Enjoyment, Anxiety, Boredom and Hopelessness for achievement outcomes in the first year of study at university. Method: We used a large sample (N = 2337) of first year university students enrolled over three consecutive academic years in a mathematics and…

  16. Study of the Relationship Between the Performance of Indian Youth on the Chicago Non-Verbal and the Wide Range Achievement Test.

    ERIC Educational Resources Information Center

    Hollingshead, Maybelle Clayton; Clayton, Charles

    The investigation examined the "Wide Range Achievement Test" (WRAT) and its subtests (spelling, reading, and arithmetic), as well as possible differences attributable to the factors of sex, with the "Chicago Non-Verbal" (CNV) as a criterion variable. The 1970 study encompassed 72 Indian students (with a mean chronological age of 13.2 for boys and…

  17. Testing a Multi-Stage Screening System: Predicting Performance on Australia's National Achievement Test Using Teachers' Ratings of Academic and Social Behaviors

    ERIC Educational Resources Information Center

    Kettler, Ryan J.; Elliott, Stephen N.; Davies, Michael; Griffin, Patrick

    2012-01-01

    This study addresses the predictive validity of results from a screening system of academic enablers, with a sample of Australian elementary school students, when the criterion variable is end-of-year achievement. The investigation included (a) comparing the predictive validity of a brief criterion-referenced nomination system with more…

  18. Investigation of the Long-Term Performance of the 324 MHz Klystrons for Achieving the Efficient Operation of the Linac at J-PARC

    NASA Astrophysics Data System (ADS)

    Hori, T.; Shinozaki, S.; Chishiro, E.; Sato, F.; Kawamura, M.; Futatsukawa, K.; Fukui, Y.; Oguri, H.

    As a part of the researches of the reliability and life time of klystrons, the cathode performance test of 324 MHz klystrons operated for 32000 hours on line has been performed at the klystron test stand. The experimental results coincide approximately with the data both reported in the literature for the cathode performance and the one obtained from the data base of RF data acquisition system. In this test, two parameters such as klystron beam perveance and knee-point were used to investigate the emission performance. It turned out that klystron beam perveance is most suitable parameter for understanding the klystron performance under operating condition on line.

  19. Site-condition map for Portugal, Western Iberia: methodology and constraints on the performance of Vs30 proxies for stable continental regions in Europe.

    NASA Astrophysics Data System (ADS)

    Vilanova, S. P.; Narciso, J.; Carvalho, J. P.; Cancela, C.; Lopes, I.; Nemser, E. S.; Borges, J.

    2014-12-01

    Information on the amplification characteristics of the near-surface formations in a regional sense is essential to adequately represent both seismic hazard maps and ground shaking maps. Due to the scarceness of shear-wave velocity data in most regions, several methods have been proposed in order to obtain first order representations of Vs30. These include the surface geology method and the topographic slope method. The latter method has become the standard way for incorporating site effects into regional studies worldwide given the convenience provided by the global Vs30 Internet server. In the framework of project SCENE we developed a shear wave velocity database for Portugal. The database consists of 87 shear-wave velocity depth profiles from a variety of lithological and geological formations. We used an iterative three-step procedure to develop the Vs30 based site-condition map: 1) to define a preliminary set of geologically defined units based on the literature; 2) to calculate the distribution of Vs30 for each unit; and 3) to perform statistical tests in order to estimate the significance of the difference in the Vs30 distribution characteristics between the units. The units were merged according to the results of the statistical tests and the procedure was repeated. We started by classifying the sites into six generalized geological units. The final set consists of three units only: F1 (igneous, metamorphic and old sedimentary rocks); F2 (Neogene and Pleistocene formations); and F3 (Holocene deposits). We used the database to evaluate the performance of Vs30 proxies. The use of proxies based either on geological units or on correlations with the topographic slope shows relatively unbiased total residual distributions of the logarithm of Vs30. However, the performance of the methods varies significantly with the generalized geological unit analyzed. Both methods are biased towards lower values of Vs30 for rock formations. The topographic-slope method is

  20. Microfluidic preparation of a highly active and stable catalyst by high performance of encapsulation of polyvinylpyrrolidone (PVP)-Pt nanoparticles in microcapsules.

    PubMed

    Nam, Jin-Oh; Kim, Jongmin; Jin, Si Hyung; Chung, Young-Min; Lee, Chang-Soo

    2016-02-15

    The encapsulation of active metals in microcapsules would be highly advantageous in maintaining or improving the reaction performance of an array of widely used chemical reactions. However, conventional methods suffer from low uniformity, complicated fabrication steps, sintering, leaching, decline of catalytic activity, and/or poor reusability. Here, we report an efficient microfluidic approach to encapsulate Pt nanoparticle stabilized by polyvinylpyrrolidone (PVP) in photocurable double-emulsion droplets with semipermeable thin shells. The encapsulated catalysts are prepared by the in situ photopolymerization of a double emulsion. The rapid and exquisite microfluidics-based fabrication process successfully generates monodisperse microcapsules without loss of the PVP-Pt nanoparticles, which is the first demonstration of the microfluidic encapsulation of active metal with promising catalytic activity. Specifically, compared to quasi-homogeneous catalysis of PVP-Pt nanoparticles for 4-nitrophenol hydrogenation, the encapsulated PVP-Pt nanoparticles demonstrate excellent catalytic activity, a leaching-proof nature, and high reusability under the same reaction conditions. We envision that the approach described here may be an example of elegant catalyst design to efficiently overcome difficult problems in active-metal encapsulation and to dramatically enhance catalytic activity by taking advantage of the unique aspects of microfluidic methods. PMID:26624530

  1. Pseudomorphic InGaAs/AlGaAs modulation-doped FET's with reduced low-frequency noise and thermally stable performance

    NASA Technical Reports Server (NTRS)

    Liu, Shih-Ming; Das, M. B.; Peng, C. K.; Klem, J.; Henderson, T.

    1987-01-01

    A high-performance MODFET structure grown by MBE with the incorporation of a single quantum well In(0.15)Ga(0.85)As layer for the transport of two-dimensional electron gas has been critically examined for its thermal stability at 80 K and low-frequency noise form 0.01 to 10 to the 8th Hz. Experimental results indicate that the behavior of this device in both these respects is much superior when compared with the same behavior of conventional MODFETs. A maximum low-field carrier mobility of 29,000 sq cm/s at 80 K and an average carrier saturation velocity of 2 x 10 to the 7th cm/s at 300 K in a 1-micron gate device clearly indicate that the quality of the pseudomorphic quantum well (InGaAs) layer is either comparable or better than that of the usual GaAs buffer layer. The deep level spectra, obtained through photo-FET measurements, and the low-frequency noise spectra at different temperatures obtained for the new pseudomorphic and conventional MODFET's have clearly indicated that contributions from various deep levels present in the new structure are significantly reduced.

  2. Stable isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry quantitative profiling of tryptophan-related neuroactive substances in human serum and cerebrospinal fluid.

    PubMed

    Hényková, Eva; Vránová, Hana Přikrylová; Amakorová, Petra; Pospíšil, Tomáš; Žukauskaitė, Asta; Vlčková, Magdaléna; Urbánek, Lubor; Novák, Ondřej; Mareš, Jan; Kaňovský, Petr; Strnad, Miroslav

    2016-03-11

    Many compounds related to L-tryptophan (L-TRP) have interesting biological or pharmacological activity, and their abnormal neurotransmission seems to be linked to a wide range of neurodegenerative and psychiatric diseases. A high-throughput method based on ultra-high performance liquid chromatography connected to electrospray tandem mass spectrometry (UHPLC-ESI-MS/MS) was developed for the quantitative analysis of L-TRP and 16 of its metabolites in human serum and cerebrospinal fluid (CSF), representing both major and minor routes of L-TRP catabolism. The combination of a fast LC gradient with selective tandem mass spectrometry enabled accurate analysis of almost 100 samples in 24h. The standard isotope dilution method was used for quantitative determination. The method's lower limits of quantification for serum and cerebrospinal fluid ranged from 0.05 to 15nmol/L and 0.3 to 45nmol/L, respectively. Analytical recoveries ranged from 10.4 to 218.1% for serum and 22.1 to 370.0% for CSF. The method's accuracy ranged from 82.4 to 128.5% for serum matrix and 90.7 to 127.7% for CSF matrix. All intra- and inter-day coefficients of variation were below 15%. These results demonstrate that the new method is capable of quantifying endogenous serum and CSF levels of a heterogeneous group of compounds spanning a wide range of concentrations. The method was used to determine the physiological levels of target analytes in serum and CSF samples from 18 individuals, demonstrating its reliability and potential usefulness in large-scale epidemiological studies. PMID:26879452

  3. Investigating the Robustness of School-Performance Ratings to Three Factors Affecting the Underlying Student-Level Academic-Achievement Scores

    ERIC Educational Resources Information Center

    Ng, Hui Leng

    2012-01-01

    Standardized-test scores are increasingly important indicators of school success. But how robust are school-performance ratings when they are based on measures derived from these scores? In my thesis, using data from Houston Independent School District (HISD) and New York State (NYS), I examined the robustness of school-performance ratings across…

  4. Ethnic-Based Equity in Teacher Judgment of Student Achievement on a Language and Literacy Curriculum-Embedded Performance Assessment for Children in Grade One

    ERIC Educational Resources Information Center

    Gallant, Dorinda J.; Moore, James L., III

    2008-01-01

    This study examined the extent to which ethnic-based differences exist in teacher ratings of African American students and White students on the language and literacy domain of a curriculum-embedded performance assessment for students in grade 1. It extended previous research on performance assessments to focus on issues related to equity in…

  5. Stable doping of carbon nanotubes via molecular self assembly

    SciTech Connect

    Lee, B.; Chen, Y.; Podzorov, V.; Cook, A.; Zakhidov, A.

    2014-10-14

    We report a novel method for stable doping of carbon nanotubes (CNT) based on methods of molecular self assembly. A conformal growth of a self-assembled monolayer of fluoroalkyl trichloro-silane (FTS) at CNT surfaces results in a strong increase of the sheet conductivity of CNT electrodes by 60–300%, depending on the CNT chirality and composition. The charge carrier mobility of undoped partially aligned CNT films was independently estimated in a field-effect transistor geometry (~100 cm²V⁻¹s⁻¹). The hole density induced by the FTS monolayer in CNT sheets is estimated to be ~1.8 ×10¹⁴cm⁻². We also show that FTS doping of CNT anodes greatly improves the performance of organic solar cells. This large and stable doping effect, easily achieved in large-area samples, makes this approach very attractive for applications of CNTs in transparent and flexible electronics.

  6. Detection of 1,N(2)-propano-2'-deoxyguanosine adducts in genomic DNA by ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry in combination with stable isotope dilution.

    PubMed

    Zhang, Ning; Song, Yuanyuan; Wu, Danni; Xu, Tian; Lu, Meiling; Zhang, Weibing; Wang, Hailin

    2016-06-10

    Crotonaldehyde (Cro) is one of widespread and genotoxic α,β-unsaturated aldehydes and can react with the exocyclic amino group of 2'-deoxyguanosine (dG) in genomic DNA to form 1,N(2)-propano-2'-deoxyguanosine (ProdG) adducts. In this study, two diastereomers of high purity were prepared, including non-isotope and stable isotope labeled ProdG adducts, and exploited stable isotope dilution-based calibration method. By taking advantage of synthesized ProdG standards, we developed a sensitive ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for accurate quantification of two diastereomers of ProdG adducts. In addition to optimization of the UHPLC separation, ammonium bicarbonate (NH4HCO3) was used as additive in the mobile phase for enhancing the ionization efficiency to ProdG adducts and facilitating MS detection. The limits of detection (LODs, S/N=3) and the limits of quantification (LOQs, S/N=10) are estimated about 50 amol and 150 amol, respectively. By the use of the developed method, both diastereomers of ProdG adducts can be detected in untreated human MRC5 cells with a frequency of 2.4-3.5 adducts per 10(8) nucleotides. Crotonaldehyde treatment dramatically increases the levels of ProdG adducts in human MRC5 in a concentration-dependent manner. PMID:27179676

  7. Approach to inherently stable interfaces for ceramic matrix composites

    SciTech Connect

    Besmann, T.M.; Kupp, E.R.; Stinton, D.P.; Shanmugham, S.

    1996-09-01

    Virtually all ceramic matrix composites require and interface coating between the fibers and matrix to achieve the desired mechanical performance. To date, the most effective interface materials for non- oxide matrix composites have been carbon and boron nitride. They are, however, susceptible to oxidation at elevated temperatures, and thus under many envisioned operating environments they will fail, possibly allowing oxidation of the fibers as well, adversely affecting mechanical behavior. Current efforts are directed toward developing stable interface coating, which include oxides and silicon carbide with appropriate thermomechanical properties.

  8. WWC Review of the Report "Closing the Social-Class Achievement Gap: A Difference-Education Intervention Improves First-Generation Students' Academic Performance and All Students' College Transition." What Works Clearinghouse Single Study Review

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2014

    2014-01-01

    For the 2014 study, "Closing the Social-Class Achievement Gap: A Difference-Education Intervention Improves First-Generation Students' Academic Performance and All Students' College Transition," researchers investigated the impact of attending a moderated panel on incoming freshmen's adjustment to college. The panel…

  9. Which Feedback Is More Effective for Pursuing Multiple Goals of Differing Importance? The Interaction Effects of Goal Importance and Performance Feedback Type on Self-Regulation and Task Achievement

    ERIC Educational Resources Information Center

    Lee, Hyunjoo

    2016-01-01

    This study examined how performance feedback type (progress vs. distance) affects Korean college students' self-regulation and task achievement according to relative goal importance in the pursuit of multiple goals. For this study, 146 students participated in a computerised task. The results showed the interaction effects of goal importance and…

  10. Thermal design and test results for SUNLITE ultra-stable reference cavity

    NASA Technical Reports Server (NTRS)

    Amundsen, Ruth M.

    1991-01-01

    SUNLITE (Stanford University-NASA Laser In-Space Technology Experiment) is a space-based experiment which uses a reference cavity to provide a stable frequency reference for a terahertz laser oscillator. Thermal stability of the cavity is a key factor in attaining a stable narrow-linewidth laser beam. The mount which is used to support and align the cavity will provide thermal isolation from the environment. The baseline requirement for thermal stability of the cavity is 0.025 C/min, but the design is directed toward achieving stability well beyond this requirement to improve the science data gained. A prototype of the cavity mount was fabricated and tested to characterize the thermal performance. The thermal vacuum test involved stable high-resolution temperature measurements and stable baseplate temperature control over long durations. Based on test data, the cavity mount design satisfies the severe requirement for the cavity thermal stability.

  11. Theoretical explanation of the polarization-converting system achieved by beam shaping and combination technique and its performance under high power conditions

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Li, Xiao; Shang, YaPing; Xu, XiaoJun

    2015-10-01

    The fiber laser has very obvious advantages and broad applications in remote welding, 3D cutting and national defense compared with the traditional solid laser. But influenced by heat effect of gain medium, nonlinear effect, stress birefringence effect and other negative factors, it's very difficult to get high power linearly polarized laser just using a single laser. For these limitations a polarization-converting system is designed using beam shaping and combination technique which is able to transform naturally polarized laser to linearly polarized laser at real time to resolve difficulties of generating high-power linearly polarized laser from fiber lasers in this paper. The principle of the Gaussian beam changing into the hollow beam passing through two axicons and the combination of the Gaussian beam and the hollow beam is discussed. In the experimental verification the energy conversion efficiency reached 93.1% with a remarkable enhancement of the extinction ratio from 3% to 98% benefited from the high conversion efficiency of axicons and the system worked fine under high power conditions. The system also kept excellent far field divergence. The experiment phenomenon also agreed with the simulation quite well. The experiment proves that this polarization-converting system will not affect laser structure which controls easily and needs no feedback and controlling system with stable and reliable properties at the same time. It can absolutely be applied to the polarization-conversion of high power laser.

  12. Achieving ICME with Multiscale Modeling: The Effects of Constituent Properties and Processing on the Performance of Laminated Polymer Matrix Composite Structures

    NASA Technical Reports Server (NTRS)

    Pineda, Evan Jorge; Bednarcyk, Brett A.; Arnold, Steven M.

    2014-01-01

    Integrated computational materials engineering (ICME) is a useful approach for tailoring the performance of a material. For fiber-reinforced composites, not only do the properties of the constituents of the composite affect the performance, but so does the architecture (or microstructure) of the constituents. The generalized method of cells is demonstrated to be a viable micromechanics tool for determining the effects of the microstructure on the performance of laminates. The micromechanics is used to predict the inputs for a macroscale model for a variety of different fiber volume fractions, and fiber architectures. Using this technique, the material performance can be tailored for specific applications by judicious selection of constituents, volume fraction, and architectural arrangement given a particular manufacturing scenario

  13. Closing the social-class achievement gap: a difference-education intervention improves first-generation students' academic performance and all students' college transition.

    PubMed

    Stephens, Nicole M; Hamedani, MarYam G; Destin, Mesmin

    2014-04-01

    College students who do not have parents with 4-year degrees (first-generation students) earn lower grades and encounter more obstacles to success than do students who have at least one parent with a 4-year degree (continuing-generation students). In the study reported here, we tested a novel intervention designed to reduce this social-class achievement gap with a randomized controlled trial (N = 168). Using senior college students' real-life stories, we conducted a difference-education intervention with incoming students about how their diverse backgrounds can shape what they experience in college. Compared with a standard intervention that provided similar stories of college adjustment without highlighting students' different backgrounds, the difference-education intervention eliminated the social-class achievement gap by increasing first-generation students' tendency to seek out college resources (e.g., meeting with professors) and, in turn, improving their end-of-year grade point averages. The difference-education intervention also improved the college transition for all students on numerous psychosocial outcomes (e.g., mental health and engagement). PMID:24553359

  14. Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene.

    PubMed

    Yan, Huan; Cheng, Hao; Yi, Hong; Lin, Yue; Yao, Tao; Wang, Chunlei; Li, Junjie; Wei, Shiqiang; Lu, Junling

    2015-08-26

    We reported that atomically dispersed Pd on graphene can be fabricated using the atomic layer deposition technique. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy both confirmed that isolated Pd single atoms dominantly existed on the graphene support. In selective hydrogenation of 1,3-butadiene, the single-atom Pd1/graphene catalyst showed about 100% butenes selectivity at 95% conversion at a mild reaction condition of about 50 °C, which is likely due to the changes of 1,3-butadiene adsorption mode and enhanced steric effect on the isolated Pd atoms. More importantly, excellent durability against deactivation via either aggregation of metal atoms or carbonaceous deposits during a total 100 h of reaction time on stream was achieved. Therefore, the single-atom catalysts may open up more opportunities to optimize the activity, selectivity, and durability in selective hydrogenation reactions. PMID:26268551

  15. The effect of parental education, prior achievement, self-efficacy, goal orientation, and effort on undergraduate science performance of Latinos and Caucasians

    NASA Astrophysics Data System (ADS)

    Stansbury, Sydney Lynn

    Compared with majority students, underrepresented minorities have demonstrated weaker undergraduate science performance. Previous research has attributed the weaker performance to socioeconomic factors that influence poorer precollege preparation. Studies also have found that, compared with majority students, underrepresented minorities are less confident about their science skills and more interested in extrinsic rewards of science careers. Social Cognitive Theory posits that low self-efficacy coupled with high extrinsic goal orientation diminishes cognitive engagement, resulting in weak performance. Applying motivational characteristics of underrepresented minority students to a Social Cognitive Model may explain why their performance is weaker than that of Caucasians. Thus, the purpose of this study was to investigate the degree to which motivation variables account for the difference between underrepresented minority and majority students' undergraduate science performance. The study was conducted at a large, predominantly Caucasian, private university located in an urban setting in the Southwest. Two hundred twenty-two students--154 Caucasians and 68 Latinos--enrolled in a general chemistry course participated. Students were administered the Motivation for Learning Questionnaire, designed specifically for this study, consisting of scales measuring the following variables: ethnicity, level of parental education, and effort exertion; self-efficacy, effort regulation, intrinsic goal orientation, and extrinsic goal orientation, measures from the Motivated Strategies for Learning Questionnaire (Pintrich, Smith, Garcia, & McKeachie, 1991); and ability orientation, a measure from the Patterns of Adaptive Learning Survey (Midgley, Maehr, & Urdan, 1995). Financial aid information, chemistry and math placement test scores, and chemistry grades were obtained from other on-campus departments. Results demonstrated that the hypotheses were only partially confirmed by the

  16. Achieving high performance non-fullerene organic solar cells through tuning the numbers of electron deficient building blocks of molecular acceptors

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Chen, Yusheng; Chen, Shangshang; Dong, Tao; Deng, Wei; Lv, Lei; Yang, Saina; Yan, He; Huang, Hui

    2016-08-01

    Two analogous dimer and tetramer compounds, SF-PDI2 and SF-PDI4, were designed, theoretically calculated, synthesized, and developed as electron acceptors for organic solar cells. The effects of the number of the electron deficient building blocks on the optical absorption, energy levels, charge transport, morphology, crystallinity, and photovoltaic performance of the molecules were investigated. In combination with two different donors, PTB7-Th and PffBT4T-2OD, the results showed that increasing the numbers of PDI building blocks is beneficial to photovoltaic performance and leads to efficiency over 5%.

  17. An Investigation of Linguistic, Cognitive, and Affective Factors that Impact English Language Learners' Performance on a State Standardized Reading Achievement Test

    ERIC Educational Resources Information Center

    Strebel Halpern, Carine S.

    2009-01-01

    The explicit teaching of reading comprehension strategies has been proposed as a means to better prepare secondary school-aged students for today's information-dense, fast-paced, fast-changing global society, and to improve the academic performance of struggling adolescent readers. This proposition of a direct and positive impact of reading…

  18. A Comparative Case Study of Veteran Superintendent's Leadership and Organizational Processes in Addressing the Academic Achievement of Students in Low Performing School Districts

    ERIC Educational Resources Information Center

    Reimer, Catherine Nicole

    2010-01-01

    This research study investigated the leadership behaviors and organizational frames utilized by two veteran superintendents of medium sized school districts in California to address issues of academic performance in their respective districts as perceived by the superintendents and their respective board members and principals. Current…

  19. Are Academic Discounting and Devaluing Double-Edged Swords? Their Relations to Global Self-Esteem, Achievement Goals, and Performance among Stigmatized Students

    ERIC Educational Resources Information Center

    Loose, Florence; Regner, Isabelle; Morin, Alexandre J. S.; Dumas, Florence

    2012-01-01

    Often taken for granted, the coexistence of benefits and costs of discounting and devaluing has never been tested. Yet, not only are there inconsistent findings about the relations between these processes and global self-esteem, but little is known about their relations to motivation and performance. Here we simultaneously examined how academic…

  20. The Effect of Evaluation on Performance: Evidence from Longitudinal Student Achievement Data of Mid-Career Teachers. NBER Working Paper No. 16877

    ERIC Educational Resources Information Center

    Taylor, Eric S.; Tyler, John H.

    2011-01-01

    The effect of evaluation on employee performance is traditionally studied in the context of the principal-agent problem. Evaluation can, however, also be characterized as an investment in the evaluated employee's human capital. We study a sample of mid-career public school teachers where we can consider these two types of evaluation effect…

  1. Experimental evidence of the kinetic performance achievable with columns packed with new 1.9μm fully porous particles of narrow particle size distribution.

    PubMed

    Ismail, Omar H; Catani, Martina; Pasti, Luisa; Cavazzini, Alberto; Ciogli, Alessia; Villani, Claudio; Kotoni, Dorina; Gasparrini, Francesco; Bell, David S

    2016-07-01

    Fully porous particles of narrow particle size distribution (nPSD) are now commercially available. In this paper, the kinetic performance of columns packed with these particles (1.9μm, 80Å pore size) has been investigated under typical reversed phase conditions by using a mixture of benzene derivatives as probes. The columns exhibited remarkably high efficiency (in the order of 300,000 theoretical plates per meter) and the possibility to be used at relatively high flow rates without loss of performance. These results contrast with previous studies on the same columns. Indeed we have found column efficiency comparable to that reported in previous work but, on the other hand, we could not observe the same dramatic loss of performance when columns were operated at high flow rates. The results presented in this paper, based on a set of six columns with different geometries (2.1 and 3.0 internal diameter×50, 75 and 100mm length), are not consistent with the previously proposed hypothesis that the unusually low intraparticle diffusion, which would characterize these particles, is the origin of the high efficiency of the columns. In a companion paper [1], a detailed investigation of the different terms leading to band broadening will be performed to point out the major contribution to plate height on nPSD columns. PMID:27234846

  2. Strategy Choice in Solving Arithmetic Word Problems: Are There Differences between Students with Learning Disabilities, G-V Poor Performance, and Typical Achievement Students?

    ERIC Educational Resources Information Center

    Gonzalez, Juan E. Jimenez; Espinel, Ana Isabel Garcia

    2002-01-01

    A study was designed to test whether there are differences between Spanish children (ages 7-9) with arithmetic learning disabilities (n=60), garden-variety (G-V) poor performance (n=44), and typical children (n=44) in strategy choice when solving arithmetic word problems. No significant differences were found between children with dyscalculia and…

  3. Graded Achievement, Tested Achievement, and Validity

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  4. Enhanced in Vitro and in Vivo Performance of Mg-Zn-Y-Nd Alloy Achieved with APTES Pretreatment for Drug-Eluting Vascular Stent Application.

    PubMed

    Liu, Jing; Zheng, Bo; Wang, Pei; Wang, Xingang; Zhang, Bin; Shi, Qiuping; Xi, Tingfei; Chen, Ming; Guan, Shaokang

    2016-07-20

    Bioabsorbable magnesium alloys are becoming prominent as temporary functional implants, as they avoid the risks generated by permanent metallic implants such as persistent inflammation and late restenosis. Nevertheless, the overfast corrosion of Mg alloys under physiological conditions hinders their wider application as medical implant materials. Here we investigate a simple one-step process to introduce a cross-linked 3-amino-propyltrimethoxysilane (APTES) silane physical barrier layer on the surface of Mg-Zn-Y-Nd alloys prior to electrostatic spraying with rapamycin-eluting poly(lactic-co-glycolic acid) (PLGA) layer. Surface microstructure was characterized by scanning electron microscope and Fourier transform infrared spectroscopy. Nanoscratch test verified the superior adhesion strength of PLGA coating in the group pretreated with APTES. Electrochemical tests combined with long-term immersion results suggested that the preferable in vitro anticorrosion behavior could be achieved by dense APTES barrier. Cell morphology and proliferation data demonstrated that APTES pretreated group resulted in remarkably preferable compatibility for both human umbilical vein endothelial cells and vascular smooth muscle cells. On the basis of excellent in vitro mechenical property, the animal study on the APTES pretreated Mg-Zn-Y-Nd stent implanted into porcine coronary arteries confirmed benign tissue compatibility as well as re-endothelialization without thrombogenesis or in-stent restenosis at six-month followup. PMID:27331417

  5. Highly Functional TNTs with Superb Photocatalytic, Optical, and Electronic Performance Achieving Record PV Efficiency of 10.1% for 1D-Based DSSCs.

    PubMed

    Qadir, Muhammad Bilal; Li, Yuewen; Sahito, Iftikhar Ali; Arbab, Alvira Ayoub; Sun, Kyung Chul; Mengal, Naveed; Memon, Anam Ali; Jeong, Sung Hoon

    2016-09-01

    Different nanostructures of TiO2 play an important role in the photocatalytic and photoelectronic applications. TiO2 nanotubes (TNTs) have received increasing attention for these applications due to their unique physicochemical properties. Focusing on highly functional TNTs (HF-TNTs) for photocatalytic and photoelectronic applications, this study describes the facile hydrothermal synthesis of HF-TNTs by using commercial and cheaper materials for cost-effective manufacturing. To prove the functionality and applicability, these TNTs are used as scattering structure in dye-sensitized solar cells (DSSCs). Photocatalytic, optical, Brunauer-Emmett-Teller (BET), electrochemical impedance spectrum, incident-photon-to-current efficiency, and intensity-modulated photocurrent spectroscopy/intensity-modulated photovoltage spectroscopy characterizations are proving the functionality of HF-TNTs for DSSCs. HF-TNTs show 50% higher photocatalytic degradation rate and also 68% higher dye loading ability than conventional TNTs (C-TNTs). The DSSCs having HF-TNT and its composite-based multifunctional overlayer show effective light absorption, outstanding light scattering, lower interfacial resistance, longer electron lifetime, rapid electron transfer, and improved diffusion length, and consequently, J SC , quantum efficiency, and record photoconversion efficiency of 10.1% using commercial N-719 dye is achieved, for 1D-based DSSCs. These new and highly functional TNTs will be a concrete fundamental background toward the development of more functional applications in fuel cells, dye-sensitized solar cells, Li-ion batteries, photocatalysis process, ion-exchange/adsorption process, and photoelectrochemical devices. PMID:27432775

  6. Stable coherent states

    NASA Astrophysics Data System (ADS)

    Zipfel, Antonia; Thiemann, Thomas

    2016-04-01

    We analyze the stability under time evolution of complexifier coherent states (CCS) in one-dimensional mechanical systems. A system of coherent states is called stable if it evolves into another coherent state. It turns out that a system can only possess stable CCS if the classical evolution of the variable z =e-i Lχ Cq for a given complexifier C depends only on z itself and not on its complex conjugate. This condition is very restrictive in general so that only a few systems exist that obey this condition. However, it is possible to access a wider class of models that in principle may allow for stable coherent states associated with certain regions in the phase space by introducing action-angle coordinates.

  7. Effective process to achieve enhanced electrochromic performances based on poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine)/ZnO nanorod composites.

    PubMed

    Lv, X J; Sun, J W; Hu, B; Ouyang, M; Fu, Z Y; Wang, P J; Bian, G F; Zhang, C

    2013-06-01

    Poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine) (PTBTPA) was electrochemically synthesized on a ZnO-coated ITO electrode to form a PTBTPA/ZnO nanocomposite electrode. The composite film exhibited a noticeable electrochromism, with reversible color changes from orange in the reduced state (0 V), olive green in the middle state (0.9 V) to dark gray in the oxidized state (1.2 V). Furthermore, the composite film showed a fast switching time of 0.92 s and a high optical contrast of 65% at 1100 nm, and retained 97% of its original electroactivity after 500 cycles, while PTBTPA film had switching time of 1.63 s and an optical contrast of 52% at 1100 nm, and retained 75% of its original electroactivity. The results demonstrated that the electrochromic performances were significantly enhanced through incorporating PTBTPA with ZnO nanorods. ZnO nanorods were introduced to modify the structure of the electrode: on one hand, to offer a directional attraction for the counterions, and on the other hand, to enhance the adhesion between the polymer and the ITO electrode. Accordingly, a conducting polymer/inorganic nanocomposite system could improve the polymer's electrochromic performance, especially in terms of the switching speed and long-term stability of the electrochromic materials. PMID:23735932

  8. Investigation of 4H-SiC insulated-gate bipolar transistor turn-off performance for achieving low power loss

    NASA Astrophysics Data System (ADS)

    Navarro, Dondee; Pesic, Iliya; Morikawa, Yoji; Furui, Yoshiharu; Miura-Mattausch, Mitiko

    2016-04-01

    The dynamic characteristics of a 4H-SiC insulated-gate bipolar transistor (IGBT) at pulse switching is investigated by incorporating reported measurements of the interface defect density to device simulation. Different trap features such as energy states and trap time constants are investigated to determine the influence of traps on circuit performance. The capture cross-section parameter used in the simulation depicts the probability of traps to trap/detrap carriers which relates to the carrier trap time constant. It is demonstrated that trapped carriers from the on-state condition cause enhanced generation current during the off-state condition, which give rise to undesired leakage current in addition to the threshold voltage shift previously reported. The device power dissipation is increased by a factor of 100 due to the defects.

  9. Ultra Stable Microwave Radiometers for Future Sea Surface Salinity Missions

    NASA Technical Reports Server (NTRS)

    Wilson, William J.; Tanner, Alan B.; Pellerano, Fernando A.; Horgan, Kevin A.

    2005-01-01

    The NASA Earth Science System Pathfinder (ESSP) mission Aquarius will measure global sea surface salinity with 100-km spatial resolution every 8 days with an average monthly salinity accuracy of 0.2 psu (parts per thousand). This requires an L-band low-noise radiometer with the long-term calibration stability of less than 0.1 K over 8 days. This three-year research program on ultra stable radiometers has addressed the radiometer requirements and configuration necessary to achieve this objective for Aquarius and future ocean salinity missions. The system configuration and component performance have been evaluated with radiometer testbeds at both JPL and GSFC. The research has addressed several areas including component characterization as a function of temperature, a procedure for the measurement and correction for radiometer system non-linearity, noise diode calibration versus temperature, low noise amplifier performance over voltage, and temperature control requirements to achieve the required stability. A breadboard radiometer, utilizing microstrip-based technologies, has been built to demonstrate this long-term stability. This report also presents the results of the radiometer test program, a detailed radiometer noise model, and details of the operational switching sequence optimization that can be used to achieve the low noise and stability requirements. Many of the results of this research have been incorporated into the Aquarius radiometer design and will allow this instrument to achieve its goals.

  10. Operational status and performance of the SLD CRID

    NASA Astrophysics Data System (ADS)

    Abe, K.; Antilogus, P.; Aston, D.; Baird, K.; Baltay, C.; Bean, A.; Ben-David, R.; Bienz, T.; Bird, F.; Caldwell, D. O.; Cavalli-Sforza, M.; Coller, J.; Coyle, P.; Coyne, D.; Dasu, S.; Dima, M.; d'Oliveira, A.; Duboscq, J.; Dunwoodie, W.; Hallewell, G.; Hasegawa, K.; Hasegawa, Y.; Huber, J.; Iwasaki, Y.; Jacques, P.; Johnson, R. A.; Kalelkar, M.; Kawahara, H.; Kwon, Y.; Leith, D. W. G. S.; Liu, X.; Lu, A.; Manly, S.; Martinez, J.; Mathys, L.; McHugh, S.; Meadows, B.; Müller, G.; Muller, D.; Nagamine, T.; Narita, S.; Nussbaum, M.; Pavel, T. J.; Plano, R.; Ratcliff, B.; Rensing, P.; Santha, A. K. S.; Schultz, D.; Sen, S.; Shank, J. T.; Shapiro, S.; Simopoulos, C.; Snyder, J.; Solodov, E.; Stamer, P.; Stockdale, I.; Suekane, F.; Toge, N.; Turk, J.; Va'vra, J.; Whitaker, J. S.; Williams, D. A.; Williams, S. H.; Willocq, S.; Wilson, R. J.; Word, G.; Yellin, S.; Yuta, H.

    1996-02-01

    The operation and performance of the SLD CRID achieved during the recently completed 1994-1995 run of the SLC will be discussed. Stable operation of liquid (C 6F 14) and gas (85% C 5F 12 and 15% N 2) radiators with good UV transparency has been achieved. Our expectations for the future SLD physics program will also be briefly discussed.

  11. The Stable Pairing Problem

    ERIC Educational Resources Information Center

    Greenwell, Raymond N.; Seabold, Daniel E.

    2014-01-01

    The Gale-Shapley stable marriage theorem is a fascinating piece of twentieth-century mathematics that has many practical applications--from labor markets to school admissions--yet is accessible to secondary school mathematics students. David Gale and Lloyd Shapley were both mathematicians and economists who published their work on the Stable…

  12. Stable isotope studies

    SciTech Connect

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  13. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    PubMed

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out. PMID:25741878

  14. Lithography-free large-area metamaterials for stable thermophotovoltaic energy conversion

    DOE PAGESBeta

    Coppens, Zachary J.; Kravchenko, Ivan I.; Valentine, Jason G.

    2016-02-08

    A large-area metamaterial thermal emitter is fabricated using facile, lithography-free techniques. The device is composed of conductive oxides, refractory ceramics, and noble metals and shows stable, selective emission after exposure to 1173 K for 22 h in oxidizing and inert atmospheres. Lastly, the results indicate that the metamaterial can be used to achieve high-performance thermophotovoltaic devices for applications such as portable power generation.

  15. Achieving greater selectivity for the analysis of o-, m-, p-methylhippuric acids in workers' urine by ultra performance liquid chromatography coupled with tandem mass spectrometry.

    PubMed

    Gagné, Sébastien

    2013-07-15

    A selective method analyzing separately o-, m- and p-methylhippuric acid isomers in workers' urine samples has been developed using ultra performance liquid chromatography coupled with tandem mass spectrometry. Chromatographic separation has been optimized to resolve the three isomers at baseline. Combined with this optimal separation, the mass spectrometer allowed rapid switching from MRM scan to full scan and product ion scan within the chromatographic peak. This feature allowed the retention of analyte chemical structure information for the three methylhippuric acid isomers in parallel with the simultaneous acquisition of quantitative data. Such an approach is unequaled for the reliability of the data generated and it can be applied to each isomer separately. The method was adjusted to a dynamic range between 0.2mM and 8.12mM for o-methylhippuric acid and p-methylhippuric acid, and between 0.41mM and 16.23mM for m-methylhippuric acid in order to cover the biological exposure index. A negligible matrix effect was observed with the conditions used. Also, intra-day and inter-day precisions were both <6% for all the concentration levels tested and the accuracy was evaluated at 97±4%. The inclusion of simultaneous full scan acquisitions did not prevent the robustness of the quantitative data. The method applied to the determination of inter-laboratory proficient test samples led to results in the tolerated range. Moreover, urine samples from workers were robustly quantified and the MHA levels were all below the biological exposure index reference value. PMID:23770736

  16. Revisiting the relationship between attributional style and academic performance

    PubMed Central

    2015-01-01

    Abstract Previous research into the relationship between attributions and academic performance has produced contradictory findings that have not been resolved. The present research examines the role of specific dimensions of attributional style in predicting subsequent academic performance in a sample of pupils (N = 979) from both high‐ and low‐achieving schools. Hierarchical regression and moderation analyses indicate that internal, stable, and global, attributional styles for positive events predict higher levels of academic performance. Global attributions for negative events were related to poorer performance across all schools. Stable attributions for negative events were related to higher levels of performance in high‐achieving schools but not in low‐achieving schools. Higher levels of internality for negative events were associated with higher performance only in low achieving schools.

  17. Performance.

    PubMed

    Chambers, David W

    2006-01-01

    High performance is difficult to maintain because it is dynamic and not well understood. Based on a synthesis of many sources, a model is proposed where performance is a function of the balance between capacity and challenge. Too much challenge produces coping (or a crash); excess capacity results in boredom. Over time, peak performance drifts toward boredom. Performance can be managed by adjusting our level of ability, our effort, the opportunity to perform, and the challenge we agree to take on. Coping, substandard but acceptable performance, is common among professionals and its long-term side effects can be debilitating. A crash occurs when coping mechanisms fail. PMID:17020177

  18. Thiophene-Diketopyrrolopyrrole-Based Quinoidal Small Molecules as Solution-Processable and Air-Stable Organic Semiconductors: Tuning of the Length and Branching Position of the Alkyl Side Chain toward a High-Performance n-Channel Organic Field-Effect Transistor.

    PubMed

    Wang, Chao; Qin, Yunke; Sun, Yuanhui; Guan, Ying-Shi; Xu, Wei; Zhu, Daoben

    2015-07-29

    A series of thiophene-diketopyrrolopyrrole-based quinoidal small molecules (TDPPQ-2-TDPPQ-5) bearing branched alkyl chains with different side-chain lengths and varied branching positions are synthesized. Field-effect transistor (FET) measurement combined with thin-film characterization is utilized to systematically probe the influence of the side-chain length and branching position on the film microstructure, molecular packing, and, hence, charge-transport property. All of these TDPPQ derivatives show air-stable n-channel transporting behavior in spin-coated FET devices, which exhibit no significant decrease in mobility even after being stored in air for 2 months. Most notably, TDPPQ-3 exhibits an outstanding n-channel semiconducting property with electron mobilities up to 0.72 cm(2) V(-1) s(-1), which is an unprecedented value for spin-coated DPP-based n-type semiconducting small molecules. A balance of high crystallinity, satisfactory thickness uniformity and continuity, and strong intermolecular interaction accounts for the superior charge-transport characteristics of TDPPQ-3 films. Our study demonstrates that tuning the length and branching position of alkyl side chains of semiconducting molecules is a powerful strategy for achieving high FET performance. PMID:26134920

  19. Bioprocessing of “Hair Waste” by Paecilomyces lilacinus as a Source of a Bleach-Stable, Alkaline, and Thermostable Keratinase with Potential Application as a Laundry Detergent Additive: Characterization and Wash Performance Analysis

    PubMed Central

    Cavello, Ivana A.; Hours, Roque A.; Cavalitto, Sebastián F.

    2012-01-01

    Paecilomyces lilacinus (Thom) Samson LPS 876, a locally isolated fungal strain, was grown on minimal mineral medium containing “hair waste,” a residue from the hair-saving unhairing process, and produced a protease with keratinolytic activity. This enzyme was biochemically characterized. The optimum reaction conditions, determined with a response surface methodology, were 60°C and pH 6.0. It was remarkably stable in a wide range of pHs and temperatures. Addition of Ca2+, Mg2+, or sorbitol was found to be effective in increasing thermal stability of the protease. PMSF and Hg2+ inhibited the proteolytic activity indicating the presence of a thiol-dependent serine protease. It showed high stability toward surfactants, bleaching agents, and solvents. It was also compatible with commercial detergents (7 mg/mL) such as Ariel, Skip, Drive, and Ace, retaining more than 70% of its proteolytic activity in all detergents after 1 h of incubation at 40°C. Wash performance analysis revealed that this protease could effectively remove blood stains. From these properties, this enzyme may be considered as a potential candidate for future use in biotechnological processes, as well as in the formulation of laundry detergents. PMID:23365760

  20. Bioprocessing of "Hair Waste" by Paecilomyces lilacinus as a Source of a Bleach-Stable, Alkaline, and Thermostable Keratinase with Potential Application as a Laundry Detergent Additive: Characterization and Wash Performance Analysis.

    PubMed

    Cavello, Ivana A; Hours, Roque A; Cavalitto, Sebastián F

    2012-01-01

    Paecilomyces lilacinus (Thom) Samson LPS 876, a locally isolated fungal strain, was grown on minimal mineral medium containing "hair waste," a residue from the hair-saving unhairing process, and produced a protease with keratinolytic activity. This enzyme was biochemically characterized. The optimum reaction conditions, determined with a response surface methodology, were 60°C and pH 6.0. It was remarkably stable in a wide range of pHs and temperatures. Addition of Ca(2+), Mg(2+), or sorbitol was found to be effective in increasing thermal stability of the protease. PMSF and Hg(2+) inhibited the proteolytic activity indicating the presence of a thiol-dependent serine protease. It showed high stability toward surfactants, bleaching agents, and solvents. It was also compatible with commercial detergents (7 mg/mL) such as Ariel, Skip, Drive, and Ace, retaining more than 70% of its proteolytic activity in all detergents after 1 h of incubation at 40°C. Wash performance analysis revealed that this protease could effectively remove blood stains. From these properties, this enzyme may be considered as a potential candidate for future use in biotechnological processes, as well as in the formulation of laundry detergents. PMID:23365760

  1. Stable isotopes in mineralogy

    USGS Publications Warehouse

    O'Neil, J.R.

    1977-01-01

    Stable isotope fractionations between minerals are functions of the fundamental vibrational frequencies of the minerals and therefore bear on several topics of mineralogical interest. Isotopic compositions of the elements H, C, O, Si, and S can now be determined routinely in almost any mineral. A summary has been made of both published and new results of laboratory investigations, analyses of natural materials, and theoretical considerations which bear on the importance of temperature, pressure, chemical composition and crystal structure to the isotopic properties of minerals. It is shown that stable isotope studies can sometimes provide evidence for elucidating details of crystal structure and can be a powerful tool for use in tracing the reaction paths of mineralogical reactions. ?? 1977 Springer-Verlag.

  2. Stable local oscillator module.

    SciTech Connect

    Brocato, Robert Wesley

    2007-11-01

    This report gives a description of the development of a Stable Local Oscillator (StaLO) multi-chip module (MCM). It is a follow-on report to SAND2006-6414, Stable Local Oscillator Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. This report describes the development of an MCM-based version of the complete StaLO, fabricated on an alumina thick film hybrid substrate.

  3. Handbook of stable strontium

    SciTech Connect

    Skoryna, S.C.

    1981-01-01

    This book presents information on the following topics: chemistry of strontium; biogeochemistry of strontium; uptake of stable strontium by plants and effects on plant growth; divalent cation-dependent deposits in paramecium; effects of strontium ion on the hydrolysis of ATP; stronium ions and membranes - screening versus binding at charged surfaces; mitochondrial granules in the liver of rats kept on stable strontium supplementation; divalent cations and regulation of cyclic nucleotides in nervous systems; strontium as the substitute for calcium in the excitation-contraction coupling of crayfish muscle fibers; hemodynamic effects of strontium in the dog; some mechanical characteristics of strontium-mediated contractions in heart muscle; effects of calcium, magnesium, and strontium on drug-receptor interactions; strontium and histamine secretion; and effects of strontium in human dental enamel.

  4. Stable Charged Cosmic Strings

    SciTech Connect

    Weigel, H.; Quandt, M.; Graham, N.

    2011-03-11

    We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius {approx_equal}10{sup -18} m. The vacuum remains stable in our model, because neutral strings are not energetically favored.

  5. Stable charged cosmic strings.

    PubMed

    Weigel, H; Quandt, M; Graham, N

    2011-03-11

    We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius ≈10(-18)  m. The vacuum remains stable in our model, because neutral strings are not energetically favored. PMID:21469786

  6. Thermally stable laminating resins

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Vaughan, R. W.; Burns, E. A.

    1972-01-01

    Improved thermally stable laminating resins were developed based on the addition-type pyrolytic polymerization. Detailed monomer and polymer synthesis and characterization studies identified formulations which facilitate press molding processing and autoclave fabrication of glass and graphite fiber reinforced composites. A specific resin formulation, termed P10P was utilized to prepare a Courtaulds HMS reinforced simulated airfoil demonstration part by an autoclave molding process.

  7. Forensic Stable Isotope Biogeochemistry

    NASA Astrophysics Data System (ADS)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  8. How Stable Is Stable? Function versus Community Composition

    PubMed Central

    Fernández, Ana; Huang, Suiying; Seston, Sherry; Xing, Jian; Hickey, Robert; Criddle, Craig; Tiedje, James

    1999-01-01

    electron flow occurred during the stable performance and indicate that an extremely dynamic community can maintain a stable ecosystem function. PMID:10427068

  9. The Effects of Chronic Achievement Motivation and Achievement Primes on the Activation of Achievement and Fun Goals

    PubMed Central

    Hart, William; Albarracín, Dolores

    2013-01-01

    This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit of means relevant to achieving or having fun. Findings indicated that achievement priming (vs. control priming) activated a goal to achieve and inhibited a goal to have fun in individuals with chronically high-achievement motivation but activated a goal to have fun and inhibited a goal to achieve in individuals with chronically low-achievement motivation. PMID:19968423

  10. Dynamically stable magnetic suspension/bearing system

    DOEpatents

    Post, Richard F.

    1996-01-01

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw's Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements.

  11. Dynamically stable magnetic suspension/bearing system

    DOEpatents

    Post, R.F.

    1996-02-27

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw`s Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements. 32 figs.

  12. Friend Influence on Achievement during Middle Childhood

    ERIC Educational Resources Information Center

    DeLay, Dawn

    2013-01-01

    This study was designed to investigate friend influence on academic achievement and task avoidance during middle childhood in a sample of 794 participants in 397 stable same-sex friendship dyads (205 girl dyads and 192 boy dyads) from four municipalities in Finland: two in Central Finland, one in Western Finland, and one in Eastern Finland.…

  13. Individual and social dimensions of Filipino students' achievement goals.

    PubMed

    Bernardo, Allan B I

    2008-10-01

    Achievement goal theory assumes that self-instrumental (mastery) achievement goals are associated with academic achievement, whereas social-instrumental (performance) goals are not. However, research on Asian students shows that both mastery and performance-approach goals are positively related to achievement; possibly because achievement motivation in Asian cultures is socially oriented and not individually oriented. The current study explored the structure of the social and individual achievement motivation orientations, and how these achievement orientations and achievement goals were related to achievement of Filipino university students. The results showed two dimensions of social-oriented achievement motivations-parent-oriented and teacher-oriented motivations-and two dimensions of individual-oriented achievement motivations-personal performance standards and personal goal choice. However, these achievement motivation orientations were not associated with achievement. Instead mastery and performance-approach goals were both positively associated with academic achievement, personal performance standards, and parent-oriented achievement motivation. PMID:22022793

  14. Persistence Length of Stable Microtubules

    NASA Astrophysics Data System (ADS)

    Hawkins, Taviare; Mirigian, Matthew; Yasar, M. Selcuk; Ross, Jennifer

    2011-03-01

    Microtubules are a vital component of the cytoskeleton. As the most rigid of the cytoskeleton filaments, they give shape and support to the cell. They are also essential for intracellular traffic by providing the roadways onto which organelles are transported, and they are required to reorganize during cellular division. To perform its function in the cell, the microtubule must be rigid yet dynamic. We are interested in how the mechanical properties of stable microtubules change over time. Some ``stable'' microtubules of the cell are recycled after days, such as in the axons of neurons or the cilia and flagella. We measured the persistence length of freely fluctuating taxol-stabilized microtubules over the span of a week and analyzed them via Fourier decomposition. As measured on a daily basis, the persistence length is independent of the contour length. Although measured over the span of the week, the accuracy of the measurement and the persistence length varies. We also studied how fluorescently-labeling the microtubule affects the persistence length and observed that a higher labeling ratio corresponded to greater flexibility. National Science Foundation Grant No: 0928540 to JLR.

  15. Highly Reflective Multi-stable Electrofluidic Display Pixels

    NASA Astrophysics Data System (ADS)

    Yang, Shu

    results of a simplified design and fabrication method are demonstrated. As advanced research topics regarding the device optical performance, firstly an optical model for evaluating reflective displays' light out-coupling efficiency is established to guide the pixel design; Furthermore, Aluminum surface diffusers are analytically modeled and then fabricated onto multi-stable electrofluidic display pixels to demonstrate truly "white" multi-stable electrofluidic display modules. The achieved results successfully promoted multi-stable electrofluidic display as excellent candidate for the ultimate E-paper device especially for larger scale signage applications.

  16. Marginally Stable Nuclear Burning

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  17. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  18. Varieties of Achievement Motivation.

    ERIC Educational Resources Information Center

    Kukla, Andre; Scher, Hal

    1986-01-01

    A recent article by Nicholls on achievement motivation is criticized on three points: (1) definitions of achievement motives are ambiguous; (2) behavioral consequences predicted do not follow from explicit theoretical assumptions; and (3) Nicholls's account of the relation between his theory and other achievement theories is factually incorrect.…

  19. Mobility and Reading Achievement.

    ERIC Educational Resources Information Center

    Waters, Theresa Z.

    A study examined the effect of geographic mobility on elementary school students' achievement. Although such mobility, which requires students to make multiple moves among schools, can have a negative impact on academic achievement, the hypothesis for the study was that it was not a determining factor in reading achievement test scores. Subjects…

  20. PASS and Reading Achievement.

    ERIC Educational Resources Information Center

    Kirby, John R.

    Two studies examined the effectiveness of the PASS (Planning, Attention, Simultaneous, and Successive cognitive processes) theory of intelligence in predicting reading achievement scores of normally achieving children and distinguishing children with reading disabilities from normally achieving children. The first study dealt with predicting…

  1. Stable local oscillator microcircuit.

    SciTech Connect

    Brocato, Robert Wesley

    2006-10-01

    This report gives a description of the development of a Stable Local Oscillator (StaLO) Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. The StaLO uses a comb generator followed by surface acoustic wave (SAW) filters. The comb generator creates a set of harmonic components of the 100MHz input signal. The SAW filters are narrow bandpass filters that are used to select the desired component and reject all others. The resulting circuit has very low sideband power levels and low phase noise (both less than -40dBc) that is limited primarily by the phase noise level of the input signal.

  2. Stable magnetic universes revisited

    NASA Astrophysics Data System (ADS)

    Tahamtan, T.; Halilsoy, M.

    2013-01-01

    Recent discovery of magnetars ( B˜1015 G) motivates us to consider magnetic universes in general relativity a new. A regular class of static, cylindrically symmetric pure magnetic field metrics is rederived in a different metric ansatz in all dimensions. Radial, time dependent perturbations show that for dimensions d>3 such spacetimes are stable at both near r≈0 and large radius r→∞. For d=3, however, simultaneous stability requirement at both, near and far radial distances can not be reconciled for time-dependent perturbations. We argue that this distinct property may be the cause for the absence of pure magnetic black holes in d=3. Restricted, numerical geodesics for neutral particles reveal a gravitational confinement around the center in the polar plane. Charged, time-like geodesics for d=4 are shown numerically to remain confined as well.

  3. Economic Impact of Stable Flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dynamic model was created to estimate the economic impact of stable flies on livestock production. Based upon a nationwide average of 10 stable flies per animal for 3 months per year, the model estimates the impact of stable flies to be $543 million to the dairy industry, $1.34 billion to pasture ...

  4. Bi-stable optical actuator

    DOEpatents

    Holdener, Fred R.; Boyd, Robert D.

    2000-01-01

    The present invention is a bi-stable optical actuator device that is depowered in both stable positions. A bearing is used to transfer motion and smoothly transition from one state to another. The optical actuator device may be maintained in a stable position either by gravity or a restraining device.

  5. Stable umbral chromospheric structures

    NASA Astrophysics Data System (ADS)

    Henriques, V. M. J.; Scullion, E.; Mathioudakis, M.; Kiselman, D.; Gallagher, P. T.; Keenan, F. P.

    2015-02-01

    Aims: We seek to understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods: Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results: We find 0.̋15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing is moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 min. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5''. Some of these structures have a correspondence in H-alpha, but we were unable to find a one-to-one correspondence for every occurrence. If the dark streaks are formed at the same heights as umbral flashes, there are systems of structures with strong departures from the vertical for all three analysed sunspots. Conclusions: Long-lived Ca II H filamentary horizontal structures are a common and likely ever-present feature in the umbra of sunspots. If the magnetic field in the chromosphere of the umbra is indeed aligned with the structures, then the present theoretical understanding of the typical umbra needs to be revisited. Movies associated to Figs. 3 and 4 are available in electronic form at http://www.aanda.org

  6. Stable superstring relics

    SciTech Connect

    Chang, S.; Coriano, C.; Faraggi, A.E. |

    1996-05-15

    The authors investigate the cosmological constraints on exotic stable matter states which arise in realistic free fermionic superstring models. These states appear in the superstring models due to a ``Wilson-line`` breaking of the unifying non-Abelian gauge symmetry. In the models that they consider the unifying SO(10) gauge symmetry is broken at the string level to SO(6) x SO(4), SU(5) x U(1) or SU(3) x SU(2) x U(1). The exotic matter states are classified according to the patterns of the SO(10) symmetry breaking. In SO(6) x XO(4) and SU(5) x U(1) type models one obtains fractionally charged states with Q{sub e.m.} = {+-}1/2. In SU(3) x SU(2) x U(1) type models one also obtains states with the regular charges under the Standard Model gauge group but with ``fractional`` charges under the U(1){sub z{prime}} symmetry. These states include down-like color triplets and electroweak doublets, as well as states which are Standard Model singlets. By analyzing the renormalizable and nonrenormalizable terms of the superpotential in a specific superstring model, the authors show that these exotic states can be stable. They investigate the cosmological constraints on the masses and relic density of the exotic states. They propose that, while the abundance and the masses of the fractionally charged states are highly constrained, the Standard Model-like states, and in particular the Standard Model singlet, are good dark matter candidates.

  7. Childhood Obesity and Cognitive Achievement.

    PubMed

    Black, Nicole; Johnston, David W; Peeters, Anna

    2015-09-01

    Obese children tend to perform worse academically than normal-weight children. If poor cognitive achievement is truly a consequence of childhood obesity, this relationship has significant policy implications. Therefore, an important question is to what extent can this correlation be explained by other factors that jointly determine obesity and cognitive achievement in childhood? To answer this question, we exploit a rich longitudinal dataset of Australian children, which is linked to national assessments in math and literacy. Using a range of estimators, we find that obesity and body mass index are negatively related to cognitive achievement for boys but not girls. This effect cannot be explained by sociodemographic factors, past cognitive achievement or unobserved time-invariant characteristics and is robust to different measures of adiposity. Given the enormous importance of early human capital development for future well-being and prosperity, this negative effect for boys is concerning and warrants further investigation. PMID:26123250

  8. Abundance of four sulfur mustard-DNA adducts ex vivo and in vivo revealed by simultaneous quantification in stable isotope dilution-ultrahigh performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Yue, Lijun; Wei, Yuxia; Chen, Jia; Shi, Huiqin; Liu, Qin; Zhang, Yajiao; He, Jun; Guo, Lei; Zhang, Tingfen; Xie, Jianwei; Peng, Shuangqing

    2014-04-21

    Sulfur mustard (SM) is a highly reactive alkylating vesicant and causes blisters upon contact with skin, eyes, and respiratory organs. It covalently links with DNAs by forming four mono- or cross-link adducts. In this article, the reference standards of SM-DNA adducts and deuterated analogues were first synthesized with simplified procedures containing only one or two steps and using less toxic chemical 2-(2-chloroethylthio)ethanol or nontoxic chemical thiodiglycol as starting materials. A sensitive and high-throughput simultaneous quantification method of N(7)-[2-[(2-hydroxyethyl)thio]-ethyl]guanine (N(7)-HETEG), O(6)-[2-[(2-hydroxyethyl)thio]-ethyl]guanine (O(6)-HETEG), N(3)-[2-[(2-hydroxyethyl)thio]-ethyl]adenine (N(3)-HETEA), and bis[2-(guanin-7-yl)ethyl]sulfide (Bis-G) in the Sprague-Dawley rat derma samples was developed by stable isotope dilution-ultrahigh performance liquid chromatography-tandem mass spectrometry (ID-UPLC-MS/MS) with the aim of revealing the real metabolic behaviors of four adducts. The method was validated, the limit of detection (S/N ratio greater than 10) was 0.01, 0.002, 0.04, and 0.11 fmol on column for N(7)-HETEG, O(6)-HETEG, Bis-G, and N(3)-HETEA, respectively, and the lower limit of quantification (S/N ratio greater than 20) was 0.04, 0.01, 0.12, and 0.33 fmol on column for N(7)-HETEG, O(6)-HETEG, Bis-G, and N(3)-HETEA, respectively. The accuracy of this method was determined to be 76% to 129% (n = 3), and both the interday (n = 6) and intraday (n = 7) precisions were less than 10%. The method was further applied for the quantifications of four adducts in the derma of adult male Sprague-Dawley rats exposed to SM ex vivo and in vivo, and all adducts had time- and dose-effect relationships. To the best of our knowledge, this is the first time that the real presented status of four DNA adducts was simultaneously revealed by the MS-based method, in which Bis-G showed much higher abundance than the result previously reported and N(3

  9. Graders' Mathematics Achievement

    ERIC Educational Resources Information Center

    Bond, John B.; Ellis, Arthur K.

    2013-01-01

    The purpose of this experimental study was to investigate the effects of metacognitive reflective assessment instruction on student achievement in mathematics. The study compared the performance of 141 students who practiced reflective assessment strategies with students who did not. A posttest-only control group design was employed, and results…

  10. Meeting a Math Achievement Crisis

    ERIC Educational Resources Information Center

    Jennings, Lenora; Likis, Lori

    2005-01-01

    An urban community spotlighted declining mathematics achievement and took some measures, in which the students' performance increased substantially. The Benjamin Banneker Charter Public School in Cambridge, Massachusetts, engaged the entire community and launched the campaign called "Math Everywhere", which changed Benjamin Banneker's culture as…

  11. Highly stable aerosol generator

    DOEpatents

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  12. Highly stable aerosol generator

    DOEpatents

    DeFord, Henry S.; Clark, Mark L.

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  13. Stable Ischemic Heart Disease.

    PubMed

    Kones, Richard; Rumana, Umme

    2016-01-01

    Classical angina refers to typical substernal discomfort triggered by effort or emotions, relieved with rest or nitroglycerin. The well-accepted pathogenesis is an imbalance between oxygen supply and demand. Goals in therapy are improvement in quality of life by limiting the number and severity of attacks, protection against future lethal events, and measures to lower the burden of risk factors to slow disease progression. New pathophysiological data, drugs, as well as conceptual and technological advances have improved patient care over the past decade. Behavioral changes to improve diets, increase physical activity, and encourage adherence to cardiac rehabilitation programs, are difficult to achieve but are effective. PMID:26567972

  14. Self-Beliefs and Student Goal Achievement

    ERIC Educational Resources Information Center

    Wesson, Caroline J.; Derrer-Rendall, Nicola M.

    2011-01-01

    Two preliminary studies are presented investigating the self-beliefs that may affect goal achievement in a student population. In Study 1, goal achievement on an abstract task, where goals are externally set by others, is considered in relation to students' levels of optimism. In Study 2, goal achievement on academic performance, where goals are…

  15. Unusually stable liquid foams.

    PubMed

    Rio, Emmanuelle; Drenckhan, Wiebke; Salonen, Anniina; Langevin, Dominique

    2014-03-01

    Obtaining stable liquid foams is an important issue in view of their numerous applications. In some of these, the liquid foam in itself is of interest, in others, the liquid foam acts as a precursor for the generation of solid foam. In this short review, we will make a survey of the existing results in the area. This will include foams stabilised by surfactants, proteins and particles. The origin of the stability is related to the slowing down of coarsening, drainage or coalescence, and eventually to their arrest. The three effects are frequently coupled and in many cases, they act simultaneously and enhance one another. Drainage can be arrested if the liquid of the foam either gels or solidifies. Coalescence is slowed down by gelified foam films, and it can be arrested if the films become very thick and/or rigid. These mechanisms are thus qualitatively easy to identify, but they are less easy to model in order to obtain quantitative predictions. The slowing down of coarsening requests either very thick or small films, and its arrest was observed in cases where the surface compression modulus was large. The detail of the mechanisms at play remains unclear. PMID:24342735

  16. Metacognition, Achievement Goals, Study Strategies and Academic Achievement: Pathways to Achievement

    ERIC Educational Resources Information Center

    Vrugt, Anneke; Oort, Frans J.

    2008-01-01

    The purpose of this research was to develop and test a model of effective self-regulated learning. Based on effort expenditure we discerned effective self-regulators and less effective self-regulators. The model comprised achievement goals (mastery, performance-approach and -avoidance goals), metacognition (metacognitive knowledge, regulation and…

  17. Stable isotope laser spectroscopy

    NASA Technical Reports Server (NTRS)

    Becker, J. F.; Yaldaei, Ramil; Mckay, Christopher P.

    1989-01-01

    Recent advances in semiconductor laser technology have produced a reliable lightweight device ideally suited for a spacecraft high resolution molecular spectrometer. Lead-salt tunable diode lasers (TDL) emit in several spectral modes, each with a very narrow linewidth of -0.0003/cm. This spectral resolution is much narrower than typical Doppler broadened molecular linewidths in the mid-IR range. Thus it is possible to detect individual rotational lines within the vibrational band and measure their intensity, which can be used to determine gas concentration. The narrow spectral lines of any impurity gas tend to lie between the narrow lines of the gas of interest. This represents a major advantage over the accepted gas chromatograph mass spectrometer (GCMS) technique for measuring gas concentrations and isotope ratios. The careful and extensive gas purification procedures required to remove impurities for reliable GCMS measurements will not be required for an IR laser gas analysis. The infrared laser gas analysis technique is being developed to measure stable isotopic ratios of gases such as CO2, CH4, N2O, and NH3. This will eventually lead to development of instruments capable of in situ istopic measurements on planets such as Mars. The carbon (C-12, C-13) isotope ratio is indicative of the type of carbon fixation mechanisms (e.g., photosynthesis, respiration) in operation on a planet, while the nitrogen (N-14, N-15) isotope ratio can probably be used to date nitrogen-bearing Martian samples. The absorbance ratio of two adjacent lines of CO2 in the 2300/cm (4.3 micron) region of the spectrum was measured. The precision of the measurement is presently better than 1 percent and significant improvement is anticipated as rapid sweep-integration techniques and computer controlled data acquistion capabilities are incorporated.

  18. Stable isotope laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Becker, J. F.; Yaldaei, Ramil; McKay, Christopher P.

    1989-03-01

    Recent advances in semiconductor laser technology have produced a reliable lightweight device ideally suited for a spacecraft high resolution molecular spectrometer. Lead-salt tunable diode lasers (TDL) emit in several spectral modes, each with a very narrow linewidth of -0.0003/cm. This spectral resolution is much narrower than typical Doppler broadened molecular linewidths in the mid-IR range. Thus it is possible to detect individual rotational lines within the vibrational band and measure their intensity, which can be used to determine gas concentration. The narrow spectral lines of any impurity gas tend to lie between the narrow lines of the gas of interest. This represents a major advantage over the accepted gas chromatograph mass spectrometer (GCMS) technique for measuring gas concentrations and isotope ratios. The careful and extensive gas purification procedures required to remove impurities for reliable GCMS measurements will not be required for an IR laser gas analysis. The infrared laser gas analysis technique is being developed to measure stable isotopic ratios of gases such as CO2, CH4, N2O, and NH3. This will eventually lead to development of instruments capable of in situ istopic measurements on planets such as Mars. The carbon (C-12, C-13) isotope ratio is indicative of the type of carbon fixation mechanisms (e.g., photosynthesis, respiration) in operation on a planet, while the nitrogen (N-14, N-15) isotope ratio can probably be used to date nitrogen-bearing Martian samples. The absorbance ratio of two adjacent lines of CO2 in the 2300/cm (4.3 micron) region of the spectrum was measured. The precision of the measurement is presently better than 1 percent and significant improvement is anticipated as rapid sweep-integration techniques and computer controlled data acquistion capabilities are incorporated.

  19. Multi-stable stochastic resonance and its application research on mechanical fault diagnosis

    NASA Astrophysics Data System (ADS)

    Li, Jimeng; Chen, Xuefeng; He, Zhengjia

    2013-10-01

    It is difficult to extract the fault features of a rotating machine via vibration analysis due to interference from background noise. Stochastic resonance (SR), used as a method of utilising noise to amplify weak signals in nonlinear dynamical systems, can detect weak signals overwhelmed in the noise. However, the detection effect of current SR methods is still unsatisfactory. To further increase the output signal-to-noise ratio (SNR) and improve the detection effect of SR, the present study proposes an improved SR method with a multi-stable model for identifying the defect-induced rotating machine faults by analysing the influence relationship between the resonance model and the resonance effect. Due to the structural characteristics of three potential wells and two barriers, the proposed resonance model can not only further amplify weak signals, but also convert into a monostable model, a bistable model or a tristable model. This result is achieved by adjusting system parameters and thus obtaining a better matching of the input signals and resonance models. Therefore, the multi-stable SR method, combined with the characteristics of the multi-stable model, can both increase the output SNR and improve the detection effect and also detect the low SNR signals and enhance the processing capability of SR for weak signals. Finally, the proposed method is applied to a gearbox fault diagnosis in a rolling mill in which two local faults located in the big gear and the pinion, respectively, are found successfully. It can be concluded that multi-stable SR method has practical value in engineering. The influence relationship between a resonance model and SR is analysed. An improved SR method with a multi-stable model is presented. The signal processing performance of multi-stable SR is analysed comparatively. Simulation and application show the validity and superiority of multi-stable SR.

  20. Heritability of Creative Achievement

    ERIC Educational Resources Information Center

    Piffer, Davide; Hur, Yoon-Mi

    2014-01-01

    Although creative achievement is a subject of much attention to lay people, the origin of individual differences in creative accomplishments remain poorly understood. This study examined genetic and environmental influences on creative achievement in an adult sample of 338 twins (mean age = 26.3 years; SD = 6.6 years). Twins completed the Creative…