Science.gov

Sample records for achievement gap narrowed

  1. Is the Achievement Gap in Indiana Narrowing? Special Report

    ERIC Educational Resources Information Center

    Spradlin, Terry E.; Kirk, Ryan; Walcott, Crystal; Kloosterman, Peter; Zaman, Khadija; McNabb, Sarah; Zapf, Jason

    2005-01-01

    In this Special Report, the Center for Evaluation and Education Policy at Indiana University examines the factors that contribute to student achievement gaps, defines the scope of the achievement gaps that exist in Indiana, evaluates whether these gaps are narrowing or will persist as Neal suggests, and offers strategies that have been identified…

  2. Narrowing the Achievement Gap: Perspectives and Strategies for Challenging Times

    ERIC Educational Resources Information Center

    Timar, Thomas B., Ed.; Maxwell-Jolly, Julie, Ed.

    2012-01-01

    This timely and thoughtful book provides multiple perspectives on closing achievement gaps. Closing persistent gaps in educational outcomes between different groups of students has been a central goal of educational policy for the past forty years. The commitment to close existing achievement gaps poses an unprecedented challenge to policy makers,…

  3. Narrowing the Standardized Achievement Gap among Ethnic Subgroups

    ERIC Educational Resources Information Center

    Grenier, Janet L.

    2013-01-01

    There is a gap in academic achievement, as evidenced on standardized tests, between European American, Latino American, and African American students in the United States. In 2011, the United States average scale scores for 8th grade students on the NAEP mathematics assessment for European American, Latino American, and African American students…

  4. Reforms that Could Help Narrow the Achievement Gap. Policy Perspectives

    ERIC Educational Resources Information Center

    Rothstein, Richard

    2006-01-01

    Americans have concluded that the achievement gap is the fault of "failing schools" because it makes no common sense that it could be otherwise. After all, how much money a family has, or a child's skin color, should not influence how well that child learns to read. If teachers know how to teach and if schools permit no distractions, children…

  5. Spanish-for-Native-Speaker Matters: Narrowing the Latino Achievement Gap through Spanish Language Instruction

    ERIC Educational Resources Information Center

    Carreira, Maria

    2007-01-01

    This paper argues that Spanish-for-native-speakers (SNS) instruction at the secondary level can play a key role in narrowing the Latino achievement gap. To this end, SNS curricula and practices should be configured to: 1) support Spanish-English biliteracy, 2) support and facilitate learning across the curriculum, 3) socialize Latino students and…

  6. Tackling Disadvantage: What Works in Narrowing the Achievement Gap in Schools

    ERIC Educational Resources Information Center

    Demie, Feyisa; Mclean, Christabel

    2015-01-01

    This study examines the success factors behind narrowing the achievement gap of disadvantaged pupils who are entitled to free school meals. A complementary methodological approach including a case study and focus group were used to explore performance and the views of teachers, parents and pupils. The key criteria for the selection of schools were…

  7. Comprehensive School Reform: Meta-Analytic Evidence of Black-White Achievement Gap Narrowing1

    PubMed Central

    Gorey, Kevin M.

    2016-01-01

    This meta-analysis extends a previous review of the achievement effects of comprehensive school reform (CSR) programs (Borman, Hewes, Overman, & Brown, 2003). That meta-analysis observed significant effects of well endowed and well-researched programs, but it did not account for race/ethnicity. This article synthesizes 34 cohort or quasi-experimental outcomes of studies that incorporated the policy-critical characteristic of race/ethnicity. Findings: compared with matched traditional schools, the black-white achievement gap narrowed significantly more among students in CSR schools. In addition, the aggregate effects were large, substantially to completely eliminating the achievement gap between African American and non-Hispanic white students in elementary and middle schools. Title I policies before or after the No Child Left Behind Act of 2001 seem to have had essentially no impact on the black-white achievement gap. Curricular and testing mandates along with the threat of sanctions without concomitant resource supports seem to have failed. This study suggests that educational achievement inequities need not be America’s destiny. It seems that they could be eliminated through concerted political will and ample resource commitments to evidence-based educational programs.

  8. Narrowing the Achievement Gap: A Review of Research, Policies, and Issues. Report.

    ERIC Educational Resources Information Center

    Hertert, Linda; Teague, Jackie

    Student achievement tests consistently show that certain groups of children score far below children in other groups. The data document a strong association between poverty and students' academic success. The achievement gap begins early in children's lives as the result of physical, social, and emotional deprivations. California is attempting to…

  9. Narrowing Participation Gaps

    ERIC Educational Resources Information Center

    Hand, Victoria; Kirtley, Karmen; Matassa, Michael

    2015-01-01

    Shrinking the achievement gap in mathematics is a tall order. One way to approach this challenge is to think about how the achievement gap manifests itself in the classroom and take concrete action. For example, opportunities to participate in activities that involve mathematical reasoning and argumentation in a safe and supportive manner are…

  10. Narrowing the Achievement Gap: Factors That Support English Learner and Hispanic Student Academic Achievement in an Urban Intermediate School

    ERIC Educational Resources Information Center

    Flores, Patricia Arleen

    2010-01-01

    A persistent and pervasive disparity in academic achievement exists between ethnic minority and English Learner students and their White and Asian peers. This qualitative single-case study of a high-poverty, high-performing middle school focused on the cultural norms, practices, and programs that were perceived to be contributing to narrowing the…

  11. Teaching a lay theory before college narrows achievement gaps at scale

    PubMed Central

    Yeager, David S.; Walton, Gregory M.; Brady, Shannon T.; Akcinar, Ezgi N.; Paunesku, David; Keane, Laura; Kamentz, Donald; Ritter, Gretchen; Duckworth, Angela Lee; Urstein, Robert; Gomez, Eric M.; Markus, Hazel Rose; Cohen, Geoffrey L.; Dweck, Carol S.

    2016-01-01

    Previous experiments have shown that college students benefit when they understand that challenges in the transition to college are common and improvable and, thus, that early struggles need not portend a permanent lack of belonging or potential. Could such an approach—called a lay theory intervention—be effective before college matriculation? Could this strategy reduce a portion of racial, ethnic, and socioeconomic achievement gaps for entire institutions? Three double-blind experiments tested this possibility. Ninety percent of first-year college students from three institutions were randomly assigned to complete single-session, online lay theory or control materials before matriculation (n > 9,500). The lay theory interventions raised first-year full-time college enrollment among students from socially and economically disadvantaged backgrounds exiting a high-performing charter high school network or entering a public flagship university (experiments 1 and 2) and, at a selective private university, raised disadvantaged students’ cumulative first-year grade point average (experiment 3). These gains correspond to 31–40% reductions of the raw (unadjusted) institutional achievement gaps between students from disadvantaged and nondisadvantaged backgrounds at those institutions. Further, follow-up surveys suggest that the interventions improved disadvantaged students’ overall college experiences, promoting use of student support services and the development of friendship networks and mentor relationships. This research therefore provides a basis for further tests of the generalizability of preparatory lay theories interventions and of their potential to reduce social inequality and improve other major life transitions. PMID:27247409

  12. Teaching a lay theory before college narrows achievement gaps at scale.

    PubMed

    Yeager, David S; Walton, Gregory M; Brady, Shannon T; Akcinar, Ezgi N; Paunesku, David; Keane, Laura; Kamentz, Donald; Ritter, Gretchen; Duckworth, Angela Lee; Urstein, Robert; Gomez, Eric M; Markus, Hazel Rose; Cohen, Geoffrey L; Dweck, Carol S

    2016-06-14

    Previous experiments have shown that college students benefit when they understand that challenges in the transition to college are common and improvable and, thus, that early struggles need not portend a permanent lack of belonging or potential. Could such an approach-called a lay theory intervention-be effective before college matriculation? Could this strategy reduce a portion of racial, ethnic, and socioeconomic achievement gaps for entire institutions? Three double-blind experiments tested this possibility. Ninety percent of first-year college students from three institutions were randomly assigned to complete single-session, online lay theory or control materials before matriculation (n > 9,500). The lay theory interventions raised first-year full-time college enrollment among students from socially and economically disadvantaged backgrounds exiting a high-performing charter high school network or entering a public flagship university (experiments 1 and 2) and, at a selective private university, raised disadvantaged students' cumulative first-year grade point average (experiment 3). These gains correspond to 31-40% reductions of the raw (unadjusted) institutional achievement gaps between students from disadvantaged and nondisadvantaged backgrounds at those institutions. Further, follow-up surveys suggest that the interventions improved disadvantaged students' overall college experiences, promoting use of student support services and the development of friendship networks and mentor relationships. This research therefore provides a basis for further tests of the generalizability of preparatory lay theories interventions and of their potential to reduce social inequality and improve other major life transitions. PMID:27247409

  13. Can Students Themselves Narrow the Socioeconomic-Status-Based Achievement Gap through Their Own Persistence and Learning Time?

    ERIC Educational Resources Information Center

    Huang, Haigen

    2015-01-01

    Despite decades of educational reforms, the achievement gap based on socioeconomic status (SES) persists in the United States. Not only does the SES-based achievement gap persist, it has also been widening. This study focused on the role of students, hypothesizing that students might reduce the SES-based achievement gap by increasing their…

  14. Instructional Strategies and Best Practices to Narrow the Mathematics Achievement Gaps between African American, Hispanic, and European American Students

    ERIC Educational Resources Information Center

    Bolden, Felicia Mickles

    2012-01-01

    A persistent mathematics achievement gap between African American, Hispanic, and European American students at one elementary school was the focus of this investigation. The research questions of this single site case study involved understanding why an achievement gap exists, and to identify the instructional strategies and best practices used to…

  15. The Narrowing Gap in New York City Teacher Qualifications and Its Implications for Student Achievement in High-Poverty Schools

    ERIC Educational Resources Information Center

    Boyd, Donald; Lankford, Hamilton; Loeb, Susanna; Rockoff, Jonah; Wyckoff, James

    2008-01-01

    Understanding what makes an effective teacher, as well as how teachers sort by their effectiveness across schools, is central to understanding and addressing student achievement gaps. Prior studies have found substantial sorting of teachers across schools, with the schools with the highest proportions of poor, non-white, and low-scoring students…

  16. Subgroup Achievement and Gap Trends: Oklahoma, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Oklahoma for 2010. Oklahoma made progress in narrowing achievement gaps for most major subgroups on the End-of-Instruction (EOI) test in Algebra I. Trends in achievement gaps could not be determined for other grades in math, or for any grades in reading, because the state…

  17. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  18. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  19. Narrow band gap amorphous silicon semiconductors

    DOEpatents

    Madan, A.; Mahan, A.H.

    1985-01-10

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  20. Narrowing the Achievement Gap and Sustaining Success: A Qualitative Study of the Norms, Practices, and Programs of a Successful High School with Urban Characteristics

    ERIC Educational Resources Information Center

    Senesac, Donald Raymond

    2010-01-01

    The academic achievement gap is the manifestation of differential learning outcomes for students typified by membership in an ethnic minority sub group or economically disadvantaged sub group. Addressing the achievement gap has become vital for the nation as a whole, and even more critical for the state of California because the majority of…

  1. Closing the Achievement Gap: Four States' Efforts

    ERIC Educational Resources Information Center

    Wixom, Micah Ann

    2015-01-01

    The achievement gap separating economically disadvantaged students from their more advantaged peers disproportionately affects students of color and has been the focus of discussion, research and controversy for more than 40 years. While the gap between black and white students narrowed considerably from the 1950s to the 1980s, that gap has…

  2. Subgroup Achievement and Gap Trends: Idaho, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Idaho for 2010. Idaho showed improvement in reading and math in grade 8 at the basic, proficient, and advanced levels for Latino and white students, low income students, and boys and girls. The state has also made progress in narrowing achievement gaps between Latino and white…

  3. Subgroup Achievement and Gap Trends: Delaware

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Delaware students showed consistent gains in math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. There were mixed results in reading. Achievement gaps narrowed in both reading and math in…

  4. Subgroup Achievement and Gap Trends: Florida

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Florida students showed gains almost across the board in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. Progress has been made in narrowing achievement gaps in both…

  5. Subgroup Achievement and Gap Trends: New Mexico

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), New Mexico showed across-the-board gains--improvements in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all major racial/ethnic subgroups and low-income students. Progress in narrowing achievement gaps at grades 4, 8,…

  6. Subgroup Achievement and Gap Trends: Pennsylvania

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Pennsylvania showed across-the-board gains--improvements in reading and math at the basic, proficient, and advanced levels for all racial/ethnic subgroups, low-income students, and boys and girls. Achievement gaps generally narrowed at grades 4 and 8 but…

  7. Subgroup Achievement and Gap Trends: Alabama

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Alabama students showed gains across the board in reading and math--at the basic, proficient, and advanced levels for all racial/ethnic subgroups, low income students, and boys and girls. Progress was made in narrowing achievement gaps between racial/ethnic…

  8. Subgroup Achievement and Gap Trends: Illinois

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Illinois students showed mostly gains in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. There was mixed progress made in narrowing achievement gaps in reading and math…

  9. Subgroup Achievement and Gap Trends: Rhode Island

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Rhode Island showed gains--improvements in reading and math at the basic, proficient, and advanced levels for most racial/ethnic subgroups, low-income students, and boys and girls. Achievement gaps between students narrowed in most cases at grades 4 and 8.…

  10. Subgroup Achievement and Gap Trends: New York

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), New York showed a clear trend of gains in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all major subgroups with just a few exceptions. Achievement gaps in reading and math also narrowed at grades 4 and 8 for most…

  11. Indium nitride: A narrow gap semiconductor

    SciTech Connect

    Wu, J.; Walukiewicz, W.; Yu, K.M.; Ager III, J.W.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2002-08-14

    The optical properties of wurtzite InN grown on sapphire substrates by molecular-beam epitaxy have been characterized by optical absorption, photoluminescence, and photomodulated reflectance techniques. All these three characterization techniques show an energy gap for InN between 0.7 and 0.8 eV, much lower than the commonly accepted value of 1.9 eV. The photoluminescence peak energy is found to be sensitive to the free electron concentration of the sample. The peak energy exhibits a very weak hydrostatic pressure dependence and a small, anomalous blueshift with increasing temperature. The bandgap energies of In-rich InGaN alloys were found to be consistent with the narrow gap of InN. The bandgap bowing parameter was determined to be 1.43 eV in InGaN.

  12. Subgroup Achievement and Gap Trends: New Jersey

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In New Jersey, achievement gaps narrowed in grade 11 reading and math for all major subgroups, with one exception. Comparable data for grade 11 by subgroup were available for 2002-2009, with a few exceptions. Because the state changed its tests at grades 4 and 8 in recent years, there were too few years of comparable data to determine trends at…

  13. A Phenomenological Study of Culturally Proficient School Leadership Resulting in the Narrowing of the Learning Gap

    ERIC Educational Resources Information Center

    Pfaller, Renee L.

    2010-01-01

    Culturally proficient school leadership and its impact on narrowing the learning gap is both timely, and needed and the focus of discussion for this study. This phenomenological qualitative research study examined culturally proficient school leadership actions that help promote a measurable narrowing of the achievement gap in five southeastern…

  14. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students?

    ERIC Educational Resources Information Center

    Kober, Nancy; McMurrer, Jennifer; Silva, Malini R.

    2011-01-01

    Title I provides extra instructional services designed to raise achievement for low-performing students in schools with relatively high poverty rates, and for all students in many of the nation's highest-poverty schools. To learn more about how well Title I students are performing academically, the Center on Education Policy (CEP) compared…

  15. Narrowing the Achievement Gap in Second-Grade Social Studies and Content Area Literacy: The Promise of a Project-Based Approach. Working Paper #26

    ERIC Educational Resources Information Center

    Halvorsen, Anne-Lise; Duke, Nell K.; Brugar, Kristy; Block, Meghan; Strachan, Stephanie; Berka, Meghan; Brown, Jason

    2012-01-01

    This design experiment addresses the question: How can second-grade students from low-SES schools attain the same levels of achievement as students from high-SES schools on standards-based social studies and content area literacy assessments? Students from two high-SES school districts were assessed in order to establish target levels of…

  16. The Racial Academic Achievement Gap

    ERIC Educational Resources Information Center

    Green, Toneka M.

    2008-01-01

    Closing the racial academic achievement gap is a problem that must be solved in order for future society to properly function. Minorities including African-American and Latino students' standardized test scores are much lower than white students. By the end of fourth grade, African American, Latino, and poor students of all races are two years…

  17. The Widening Income Achievement Gap

    ERIC Educational Resources Information Center

    Reardon, Sean F.

    2013-01-01

    Has the academic achievement gap between high-income and low-income students changed over the last few decades? If so, why? And what can schools do about it? Researcher Sean F. Reardon conducted a comprehensive analysis of research to answer these questions and came up with some striking findings. In this article, he shows that income-related…

  18. Subgroup Achievement and Gap Trends: South Carolina, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in South Carolina for 2010. South Carolina introduced new tests in grades 3-8, so trend data that include 2009 are not available. Progress in narrowing achievement gaps at grade 10 was mixed. Comparable data were available for 2004-2009 at grade 10. (Contains 9 tables.) [For the…

  19. Narrowing the Achievement Gap in Science.

    ERIC Educational Resources Information Center

    Koba, Susan B.

    1996-01-01

    An inner-city Omaha high school created an untracked, wholly desegregated 2-year thematic science curriculum for all 9th and 10th graders. Under the outdoor community study theme, students participate in a simulated archaeological dig of an Omaha Indian earth lodge, study the school grounds' ecological status, and design areas along a proposed…

  20. Period Effects, Cohort Effects, and the Narrowing Gender Wage Gap

    PubMed Central

    Campbell, Colin; Pearlman, Jessica

    2015-01-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use Age-Period-Cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages. PMID:24090861

  1. Period effects, cohort effects, and the narrowing gender wage gap.

    PubMed

    Campbell, Colin; Pearlman, Jessica

    2013-11-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use age-period-cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages. PMID:24090861

  2. Black Phosphorus: Narrow Gap, Wide Applications.

    PubMed

    Castellanos-Gomez, Andres

    2015-11-01

    The recent isolation of atomically thin black phosphorus by mechanical exfoliation of bulk layered crystals has triggered an unprecedented interest, even higher than that raised by the first works on graphene and other two-dimensionals, in the nanoscience and nanotechnology community. In this Perspective, we critically analyze the reasons behind the surge of experimental and theoretical works on this novel two-dimensional material. We believe that the fact that black phosphorus band gap value spans over a wide range of the electromagnetic spectrum (interesting for thermal imaging, thermoelectrics, fiber optics communication, photovoltaics, etc.) that was not covered by any other two-dimensional material isolated to date, its high carrier mobility, its ambipolar field-effect, and its rather unusual in-plane anisotropy drew the attention of the scientific community toward this two-dimensional material. Here, we also review the current advances, the future directions and the challenges in this young research field. PMID:26600394

  3. Detonation propagation in narrow gaps with various configurations

    NASA Astrophysics Data System (ADS)

    Monwar, M.; Yamamoto, Y.; Ishii, K.; Tsuboi, T.

    2007-08-01

    In general all detonation waves have cellular structure formed by the trajectory of the triple points. This paper aims to investigate experimentally the propagation of detonation in narrow gaps for hydrogen-oxygen-argon mixtures in terms of various gap heights and gap widths. The gap of total length 1500 mm was constructed by three pair of stainless plates, each of them was 500 mm in length, which were inserted in a detonation tube. The gap heights were varied from 1.2 mm to 3.0 mm while the gap widths were varied from 10 mm to 40 mm. Various argon dilution rates were tested in the present experiments to change the size of cellular structure. Attempts have been made by means of reaction front velocity, shock front velocity, and smoked foil to record variations of cellular structure inside the gaps. A combination probe composed of a pressure and an ion probe detected the arrival of the shock and the reaction front individually at one measurement point. Experimental results show that the number of the triple points contained in detonation front decreases with decrease in the gap heights and gap widths, which lead to larger cellular structures. For mixtures with low detonability, cell size is affected by a certain gap width although conversely cell size is almost independent of gap width. From the present result it was found that detonation propagation inside the gaps is strongly governed by the gap height and effects of gap width is dependent on detonability of mixtures.

  4. Pyridalthiadiazole-based narrow band gap chromophores.

    PubMed

    Henson, Zachary B; Welch, Gregory C; van der Poll, Thomas; Bazan, Guillermo C

    2012-02-29

    π-Conjugated materials containing pyridal[2,1,3]thiadiazole (PT) units have recently achieved record power conversion efficiencies of 6.7% in solution-processed, molecular bulk-heterojunction (BHJ) organic photovoltaics. Recognizing the importance of this new class of molecular systems and with the aim of establishing a more concrete path forward to predict improvements in desirable solid-state properties, we set out to systematically alter the molecular framework and evaluate structure-property relationships. Thus, the synthesis and properties of 13 structurally related D(1)-PT-D(2)-PT-D(1) compounds, where D represents a relatively electron-rich aromatic segment compared to PT, are provided. Physical properties were examined using a combination of absorption spectroscopy, cyclic voltammetry, thermal gravimetric analysis, differential scanning calorimetry, and solubility analysis. Changes to end-capping D(1) units allowed for fine control over electronic energy levels both in solution and in the bulk. Substitution of different alkyl chains on D(2) gives rise to controllable melting and crystallization temperatures and tailored solubility. Alterations to the core donor D(2) lead to readily identifiable changes in all properties studied. Finally, the regiochemistry of the pyridal N-atom in the PT heterocycle was investigated. The tailoring of structures via subtle structural modifications in the presented molecular series highlights the simplicity of accessing this chromophore architecture. Examination of the resulting materials properties relevant for device fabrication sets forth which can be readily predicted by consideration of molecular structure and which lack a systematic understanding. Guidelines can be proposed for the design of new molecular frameworks with the possibility of outperforming the current state of the art OPV performance. PMID:22283693

  5. Critical Heat Flux in Inclined Rectangular Narrow Gaps

    SciTech Connect

    Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

  6. Closing the Achievement Gap: Challenges and Opportunities

    ERIC Educational Resources Information Center

    Robards, Shirley N.

    2008-01-01

    Closing the achievement gap between low- and high-achieving public school students is an important goal of public education. This article explores background information and research and discusses examples of best practices to close the achievement gap. Several plans have been proposed as ways to enhance the achievement of under-represented…

  7. Reducing the White-Nonwhite Achievement Gap.

    ERIC Educational Resources Information Center

    Ramey, Madelaine

    It is well documented that there continues to be a gap between white and nonwhite student achievement. A study develops and tests a measure of white-nonwhite achievement gap reduction. The ultimate purpose is to use the measure as the dependent variable in a qualitative study of what works in reducing the gap. The strategy used in addressing this…

  8. Model of Layered Weld Formation Under Narrow Gap Pulse Welding

    NASA Astrophysics Data System (ADS)

    Krampit, A. G.

    2016-04-01

    The model parameters of narrow gap pulse welding can be divided into input, internal and output ones. The breadth of gap, that is, clearance breadth between upright edges is one of key parameters securing high quality of a weld joint. The paper presents theoretical outcomes for the model of layered weld formation under narrow gap pulse welding. Based on these studies is developed model of processes, which occur in the weld pool under pulse grove welding. It comprises the scheme of liquid metal motion in the weld pool, scheme of fusion with the side edge and in the bottom part, and the scheme of welding current impulse effect on the structure of a weld joint.

  9. Closing the Achievement Gap. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2003-01-01

    The "achievement gap" is a matter of race and class. Across the U.S., a gap in academic achievement persists between minority and disadvantaged students and their white counterparts. This is one of the most pressing education-policy challenges that states currently face. For decades, policymakers, researchers, and school reformers have sought ways…

  10. School Choice and the Achievement Gap

    ERIC Educational Resources Information Center

    Jeynes, William H.

    2014-01-01

    The possibility is examined that school choice programs could be a means to reducing the achievement gap. Data based on meta-analytic research and the examination of nationwide data sets suggest that school choice programs that include private schools could reduce the achievement gap by 25%. The propounding of this possibility is based on research…

  11. Subgroup Achievement and Gap Trends: Mississippi, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Mississippi for 2010. Mississippi made changes to its state testing program in the 2007-08 school year. Therefore, subgroup and achievement gap trends could not be calculated because fewer than three consecutive years of data were available, too short a period to constitute a…

  12. Unmet Promise: Raising Minority Achievement. The Achievement Gap.

    ERIC Educational Resources Information Center

    Johnston, Robert C.; Viadero, Debra

    2000-01-01

    This first in a four-part series on why academic achievement gaps persist discusses how to raise minority achievement. It explains how earlier progress in closing the gap has stalled, while at the same time, the greater diversity of student populations and the rapid growth of the Hispanic population and of other ethnic groups have reshaped the…

  13. Mobility and the Achievement Gap.

    ERIC Educational Resources Information Center

    Skandera, Hanna; Sousa, Richard

    2002-01-01

    Research indicates that low achievement scores relate significantly to high school mobility rates. One explanation for this relationship is curricular inconsistency. Some suggest that school choice could contribute to a solution by breaking the link between a child's home address and school address, thus allowing students to remain at one school…

  14. Electronic characterization of defects in narrow gap semiconductors

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1993-01-01

    The study of point defects in semiconductors has a long and honorable history. In particular, the detailed understanding of shallow defects in common semiconductors traces back to the classic work of Kohn and Luttinger. However, the study of defects in narrow gap semiconductors represents a much less clear story. Here, both shallow defects (caused by long range potentials) and deep defects (from short range potentials) are far from being completely understood. In this study, all results are calculational and our focus is on the chemical trend of deep levels in narrow gap semiconductors. We study substitutional (including antisite), interstitial and ideal vacancy defects. For substitutional and interstitial impurities, the efects of relaxation are included. For materials like Hg(1-x)Cd(x)Te, we study how the deep levels vary with x, of particular interest is what substitutional and interstitial atoms yield energy levels in the gap i.e. actually produce deep ionized levels. Also, since the main technique utilized is Green's functions, we include some summary of that method.

  15. Radiative recombination of hot carriers in narrow-gap semiconductors

    SciTech Connect

    Pavlov, N. V.; Zegrya, G. G.

    2012-01-15

    The mechanism of the radiative recombination of hot carriers in narrow-gap semiconductors is analyzed using the example of indium antimonide. It is shown that the CHCC Auger recombination process may lead to pronounced carrier heating at high excitation levels. The distribution functions and concentrations of hot carriers are determined. The radiative recombination rate of hot carriers and the radiation gain coefficient are calculated in terms of the Kane model. It is demonstrated that the radiative recombination of hot carriers will make a substantial contribution to the total radiative recombination rate at high carrier concentrations.

  16. Subgroup Achievement and Gap Trends: Vermont, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Vermont for 2010. Vermont's demographic profile is such that achievement trends could only be determined for white, male and female, and low-income student subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), the white, low-income,…

  17. Subgroup Achievement and Gap Trends: Wyoming, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Wyoming for 2010. Wyoming's demographic profile is such that achievement trends could only be determined for white, Latino, male and female, and low-income student subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), the white,…

  18. Lags in Minority Achievement Defy Traditional Explanations. The Achievement Gap.

    ERIC Educational Resources Information Center

    Viadero, Debra; Johnston, Robert C.

    2000-01-01

    This second in a four-part series on why academic achievement gaps exist notes that standard explanations for why minority students trail behind non-Hispanic whites are not good enough, suggesting that no single explanation for the gap exists, but instead a multitude of factors are influential. Poverty, though not the single most important cause,…

  19. Minority Gaps Smaller in Some Pentagon Schools. The Achievement Gap.

    ERIC Educational Resources Information Center

    Viadero, Debra

    2000-01-01

    This third in a four-part series on why academic achievement gaps exist explains how U.S. Department of Defense schools for children of military families offer lessons on how to raise academic achievement among minority students. Minority students in these schools do better than their counterparts almost anywhere in the United States on…

  20. Trends in the Black-White Achievement Gap: Clarifying the Meaning of Within- and Between-School Achievement Gaps. NBER Working Paper No. 14213

    ERIC Educational Resources Information Center

    Page, Lindsay C.; Murnane, Richard J.; Willett, John B.

    2008-01-01

    We decompose black-white achievement gap trends between 1971 and 2004 into trends in within- and between-school differences. We show that the previous finding that narrowing within-school inequality explains most of the decline in the black-white achievement gap between 1971 and 1988 is sensitive to methodology. Employing a more detailed partition…

  1. Simultaneous band-gap narrowing and carrier-lifetime prolongation of organic-inorganic trihalide perovskites.

    PubMed

    Kong, Lingping; Liu, Gang; Gong, Jue; Hu, Qingyang; Schaller, Richard D; Dera, Przemyslaw; Zhang, Dongzhou; Liu, Zhenxian; Yang, Wenge; Zhu, Kai; Tang, Yuzhao; Wang, Chuanyi; Wei, Su-Huai; Xu, Tao; Mao, Ho-Kwang

    2016-08-01

    The organic-inorganic hybrid lead trihalide perovskites have been emerging as the most attractive photovoltaic materials. As regulated by Shockley-Queisser theory, a formidable materials science challenge for improvement to the next level requires further band-gap narrowing for broader absorption in solar spectrum, while retaining or even synergistically prolonging the carrier lifetime, a critical factor responsible for attaining the near-band-gap photovoltage. Herein, by applying controllable hydrostatic pressure, we have achieved unprecedented simultaneous enhancement in both band-gap narrowing and carrier-lifetime prolongation (up to 70% to ∼100% increase) under mild pressures at ∼0.3 GPa. The pressure-induced modulation on pure hybrid perovskites without introducing any adverse chemical or thermal effect clearly demonstrates the importance of band edges on the photon-electron interaction and maps a pioneering route toward a further increase in their photovoltaic performance. PMID:27444014

  2. A Historical Perspective on Closing Achievement Gaps

    ERIC Educational Resources Information Center

    Guskey, Thomas R.

    2005-01-01

    Although much has been written recently about gaps in the achievement of different groups of students, the problem has been with us for many years. This manuscript presents a historical perspective of the problem, viewing it as one of reducing variation in students' achievement. Specifically, it reviews the work of renowned educator Benjamin S.…

  3. Subgroup Achievement and Gap Trends: Kansas, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Kansas for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Kansas students showed across-the-board gains--both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and…

  4. Subgroup Achievement and Gap Trends: South Dakota

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This year the Center on Education Policy analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps between…

  5. Subgroup Achievement and Gap Trends: Michigan

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Michigan showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low income students, and boys and girls. Results on achievement gaps were mixed. Comparable data were…

  6. Subgroup Achievement and Gap Trends: Massachusetts, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Massachusetts for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Massachusetts showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low…

  7. Subgroup Achievement and Gap Trends: Kentucky, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Kentucky for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Kentucky showed mostly gains in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls.…

  8. Subgroup Achievement and Gap Trends: Missouri

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Missouri showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low income students, and boys and girls. Results on achievement gaps were mixed. Comparable data were…

  9. Subgroup Achievement and Gap Trends: Texas, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Texas for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Texas showed across-the-board gains--improvements in reading and math at the basic, proficient, and advanced levels for all racial/ethnic subgroups, low-income students, and…

  10. Subgroup Achievement and Gap Trends: Nevada, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Nevada for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Nevada showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low income…

  11. Photovoltaic effect for narrow-gap Mott insulators

    NASA Astrophysics Data System (ADS)

    Manousakis, Efstratios

    2012-02-01

    Solar cells, based on conventional band-semiconductors, have low efficiency for conversion of solar into electrical energy. The main reason is that the excess energy of the photon absorbed by an electron/hole pair beyond the band-gap becomes heat through electron-phonon scattering and phonon emission; through these processes electrons and holes relax to their band edges within a characteristic time scale of the order of 10-12-10-13 secs. We will discuss that a narrow-gap Mott insulator can produce a significant photovoltaic effect and, more importantly, if appropriately chosen it can lead to solar cells of high efficiency. In this case, a single solar photon can produce multiple electron/hole (doublon/hole) pairs, an effect known as impact ionization, faster than other relaxation processes such as relaxation through phonons. It has been proposed previously that this process could lead to an efficient solar cell using band-gap semiconductors; however, the characteristic time-scale for impact ionization is comparable to that for electron-phonon relaxation in band-gap semiconductors. The reason that a Mott insulator can behave differently is that the large Coulomb repulsion present in a Mott insulator leads to a large enhancement of the impact ionization rate. Provided that this enhancement does occur in an appropriately chosen Mott insulator, it can be demonstrated that the efficiency can improve significantly over conventional band-insulators. At present, we are doing calculations on specific transition-metal-oxide based materials believed to be Mott-insulators using extensions of the density functional theory (hybrid functionals) in combination with many-body perturbation theory. Our goal is to determine a promising candidate with suitable band structure and transition matrix elements leading to fast transition rates for impact ionization to occur in a time-scale faster than other relaxation processes.

  12. Want to Close the Achievement Gap? Close the Teaching Gap

    ERIC Educational Resources Information Center

    Darling-Hammond, Linda

    2015-01-01

    For years now, educators have looked to international tests as a yardstick to measure how well students from the United States are learning compared with their peers. The answer has been: not so well. The United States has been falling further behind other nations and has struggled with a large achievement gap. Federal policy under No Child Left…

  13. Folk Belief Theory, the Rigor Gap, and the Achievement Gap

    ERIC Educational Resources Information Center

    Torff, Bruce

    2014-01-01

    Folk belief theory is suggested as a primary cause for the persistence of the achievement gap. In this research-supported theory, culturally specified folk beliefs about learning and teaching prompt educators to direct more rigorous curriculum to high-advantage students but not to low-advantage students, resulting in impoverished pedagogy in…

  14. Narrow Band Gap Lead Sulfide Hole Transport Layers for Quantum Dot Photovoltaics.

    PubMed

    Zhang, Nanlin; Neo, Darren C J; Tazawa, Yujiro; Li, Xiuting; Assender, Hazel E; Compton, Richard G; Watt, Andrew A R

    2016-08-24

    The band structure of colloidal quantum dot (CQD) bilayer heterojunction solar cells is optimized using a combination of ligand modification and QD band gap control. Solar cells with power conversion efficiencies of up to 9.33 ± 0.50% are demonstrated by aligning the absorber and hole transport layers (HTL). Key to achieving high efficiencies is optimizing the relative position of both the valence band and Fermi energy at the CQD bilayer interface. By comparing different band gap CQDs with different ligands, we find that a smaller band gap CQD HTL in combination with a more p-type-inducing CQD ligand is found to enhance hole extraction and hence device performance. We postulate that the efficiency improvements observed are largely due to the synergistic effects of narrower band gap QDs, causing an upshift of valence band position due to 1,2-ethanedithiol (EDT) ligands and a lowering of the Fermi level due to oxidation. PMID:27421066

  15. Closing the Achievement Gap on ACT & SAT

    ERIC Educational Resources Information Center

    Anderson, David

    2010-01-01

    Research has focused on four groups of factors and the achievement gap: (1) student characteristics (high school GPA, attendance patterns, courses taken in high school, participation in extra-curricular activities, etc.); (2) family characteristics (family structure, in home, parents' level of education, mobility, etc.); (3) school-based…

  16. Getting to Results. Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Read, Tory

    2008-01-01

    The "Closing the Achievement Gap" series explores the Casey Foundation's education investments and presents stories, results, and lessons learned. This publication describes efforts to develop a flexible but rigorous results measurements system that enables the Foundation and its grantees to reflect on practice and course-correct as needed to…

  17. Subgroup Achievement and Gap Trends: Hawaii

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    Hawaii showed improvement in reading and math in grade 8 at the basic, proficient, and advanced levels for Asian and white students, low income students, and boys and girls. Gains in math tended to be larger than in reading. Trends in closing achievement gaps were mixed. Comparable data were available from 2007 through 2009. (Contains 9 tables.)…

  18. Decomposing Achievement Gaps among OECD Countries

    ERIC Educational Resources Information Center

    Zhang, Liang; Lee, Kristen A.

    2011-01-01

    In this study, we use decomposition methods on PISA 2006 data to compare student academic performance across OECD countries. We first establish an empirical model to explain the variation in academic performance across individuals, and then use the Oaxaca-Blinder decomposition method to decompose the achievement gap between each of the OECD…

  19. High Ability Readers and the Achievement Gap

    ERIC Educational Resources Information Center

    Hunsaker, Scott L.; Parke, Cynthia J.; Bramble, Joan G.

    2004-01-01

    To close the achievement gap, the "No Child Left Behind" law calls for all students to make appropriate yearly progress. This presumably means that progress is being made by capable readers at the same time progress is being made by struggling readers. However, there appear to be unintended effects of "No Child Left Behind" that may impede the…

  20. Preparing Educational Leaders to Close Achievement Gaps

    ERIC Educational Resources Information Center

    Johnson, Joseph F., Jr.; Uline, Cynthia L.

    2005-01-01

    For more than 25 years, researchers have described the critical roles leaders play in creating effective schools and school districts. If U.S. schools are to close achievement gaps, their leaders must possess the appropriate knowledge, dispositions, and skills to assume these critical roles. The Interstate School Leadership Licensure Consortium…

  1. K-8 Charter Schools: Closing the Achievement Gap. Innovations in Education

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    This guide is part of a series produced by the U.S. Department of Education, and it builds on two previous works: "Successful Charter Schools" (ED493615) and "Charter High Schools Closing the Achievement Gap" (ED494482). It profiles seven K-8 charter schools that are making headway in narrowing gaps in achievement. It examines factors contributing…

  2. The Effects of Reading Recovery™ on the American Indian/Non-American Indian Achievement Gap

    ERIC Educational Resources Information Center

    Collins, Mary L.

    2012-01-01

    Despite the attention being paid to the achievement gap of minorities, the regulations and laws being enacted, the research being conducted, and the funding made available to narrow the achievement gap, there is evidence that shows it still exists for American Indians. This study examined the effects of Reading Recovery, an early literacy…

  3. Electronic characterization of defects in narrow gap semiconductors

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1994-01-01

    We use a Green's function technique to calculate the position of deep defects in narrow gap semiconductors. We consider substitutional (including antisite), vacancy, and interstitial (self and foreign) deep defects. We also use perturbation theory to look at the effect of nonparabolic bands on shallow defect energies and find nonparabolicity can increase the binding by 10 percent or so. We consider mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). For substitutional and interstitial defects we look at the situation with and without relaxation. For substitutional impurities in MCT, MZT, and MZS, we consider x (the concentration of Cd or Zn) in the range 0.1 less than x less than 0.3 and also consider appropriate x so E(sub g) = 0.1 eV for each of the three compounds. We consider several cation site s-like deep levels and anion site p-like levels. For E(sub g) = 0.1 eV, we also consider the effects of relaxation. Similar comments apply to the interstitial deep levels whereas no relaxation is considered for the ideal vacancy model. Relaxation effects can be greater for the interstitial than the substitutional cases. Specific results are given in figures and tables and comparison to experiment is made in a limited number of cases. We find, for example, that I, Se, S, Rn, and N are possible cation site, s-like deep levels in MCT and Zn and Mg are for anion site, p-like levels (both levels for substitutional cases). The corresponding cation and anion site levels for interstitial deep defects are (Au, Ag, Hg, Cd, Cu, Zn) and (N, Ar, O, F). For the substitutional cases we have some examples of relaxation moving the levels into the band gap, whereas for the interstitial case we have examples where relaxation moves it out of the band gap. Future work involves calculating the effects of charge state interaction and seeing the effect of relaxation on vacancy levels.

  4. Examining Different School Structures' Effect on Reducing the Achievement Gap Between African-American and White Students

    ERIC Educational Resources Information Center

    Reini, Eric William

    2004-01-01

    The fact that an achievement gap between White and African-American students exists is undisputed. The reasons for this gap are many and complex. Evidence does exist, though, that this gap can be narrowed and potentially eliminated. Evidence also exists that demonstrates that when the gap in academic achievement becomes equal African-Americans are…

  5. 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.

  6. A Special Section on the Achievement Gap--Reframing the Achievement Gap

    ERIC Educational Resources Information Center

    Evans, Robert

    2005-01-01

    The achievement gap, the persistent disparity between the performance of African American and Hispanic students and that of white and Asian American students, is perhaps the most stubborn, perplexing issue confronting American schools today. Closing the gap is widely seen as important not just for the education system but ultimately for the…

  7. Narrowing the Gap in Outcomes for Vulnerable Groups: A Review of the Research Evidence

    ERIC Educational Resources Information Center

    Kendall, Sally; Straw, Suzanne; Jones, Megan; Springate, Iain; Grayson, Hilary

    2008-01-01

    This report presents findings from a review of the best evidence on narrowing the gap in outcomes across the five Every Child Matters (ECM) areas for vulnerable groups in the context of improving outcomes for all. The review was commissioned to prepare the ground for work on "Narrowing the Gap" with participating local authorities (LAs). Although…

  8. Narrowing the Gap in Outcomes: Early Years (0-5 Years)

    ERIC Educational Resources Information Center

    Springate, Ian; Atkinson, Mary; Straw, Suzanne; Lamont, Emily; Grayson, Hilary

    2008-01-01

    This report was commissioned by the Local Government Association (LGA) to inform the Department for Children, Schools and Families (DCSF) and LGA work on "Narrowing the Gap." It focuses on early years' provision and presents findings from a review of the best evidence on narrowing the gap in outcomes across the five Every Child Matters (ECM) areas…

  9. Attacking the African American-White Achievement Gap on College Admissions Tests

    ERIC Educational Resources Information Center

    Nettles, Michael T.; Millett, Catherine M.; Ready, Douglas D.

    2003-01-01

    The African American-white achievement gap exists even among the youngest children; African American students arrive at kindergarten considerably behind their white peers in measurable cognitive skills. Although the gap has narrowed somewhat over the past several decades, the average African American still scores below 75 percent of white students…

  10. The Hispanic-White Achievement Gap in Math and Reading in the Elementary Grades

    ERIC Educational Resources Information Center

    Reardon, Sean F.; Galindo, Claudia

    2009-01-01

    This article describes the developmental patterns of Hispanic-White math and reading achievement gaps in elementary school, paying attention to variation in these patterns among Hispanic subgroups. Compared to non-Hispanic White students, Hispanic students enter kindergarten with much lower average math and reading skills. The gaps narrow by…

  11. Career Attainment among Healthcare Executives: Is the Gender Gap Narrowing?

    ERIC Educational Resources Information Center

    Branin, Joan Julia

    2009-01-01

    Health care occupations are expected to be among the fastest growing professions in the next ten years. With such incredible growth expected in employment and wages, and with women's participation in the industry remaining strong, are women in the health care industry, particularly those in health care administration, experiencing a narrowing of…

  12. Causes of and Solutions to the Achievement Gap: Teachers' Perceptions

    ERIC Educational Resources Information Center

    Ratcliff, Nancy J.; Costner, Richard H.; Carroll, Kimberly L.; Jones, Cathy R.; Sheehan, Heather Chase; Hunt, Gilbert H.

    2016-01-01

    Survey results from 874 educators regarding the achievement gap are shared. The importance of the achievement gap, causes of and solutions to the achievement gap, and performance expectations for students in their schools are explored. Implications for teacher educators are discussed as related to both pre-service and in-service training programs.

  13. Minority carrier blocking to enhance the thermoelectric figure of merit in narrow-band-gap semiconductors

    NASA Astrophysics Data System (ADS)

    Bahk, Je-Hyeong; Shakouri, Ali

    2016-04-01

    We present detailed theoretical predictions on the enhancement of the thermoelectric figure of merit by minority carrier blocking with heterostructure barriers in bulk narrow-band-gap semiconductors. Bipolar carrier transport, which is often significant in a narrow-band-gap material, is detrimental to the thermoelectric energy conversion efficiency as it suppresses the Seebeck coefficient and increases the thermal conductivity. When the minority carriers are selectively prevented from participating in conduction while the transport of majority carriers is relatively unaffected by one-sided heterobarriers, the thermoelectric figure of merit can be drastically enhanced. Thermoelectric transport properties such as Seebeck coefficient, electrical conductivity, and electronic thermal conductivity including the bipolar term are calculated with and without the barriers based on the near-equilibrium Boltzmann transport equations under the relaxation time approximation to investigate the effects of minority carrier barriers on the thermoelectric figure of merit. For this, we provide details of carrier transport modeling and fitting results of experimental data for three important material systems, B i2T e3 -based alloys, M g2S i1 -xS nx , and S i1 -xG ex , that represent, respectively, near-room-temperature (300 K-500 K), midtemperature (600 K-900 K), and high-temperature (>1000 K ) applications. Theoretical maximum enhancement of thermoelectric figure of merit that can be achieved by minority carrier blocking is quantified and discussed for each of these semiconductors.

  14. Further improvements in program to calculate electronic properties of narrow band gap materials

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1991-01-01

    Research into the properties of narrow band gap materials during the period 15 Jun. to 15 Dec. 1991 is discussed. Abstracts and bibliographies from papers presented during this period are reported. Graphs are provided.

  15. Can Technology Narrow the Black-White Achievement Gap?

    ERIC Educational Resources Information Center

    Beglau, Monica M.

    2005-01-01

    The author begins this article by relating the experiences of her fourth-grade students who had just completed an intensive four-week project that involved crafting arguments to convince their local school board to allow a field trip to the Missouri state capitol so they could explore their state's government in person and in depth. Just one year…

  16. Operation of narrow gap RPC with tetrafluoroethane based mixtures.

    NASA Astrophysics Data System (ADS)

    Koreshev, V.; Ammosov, V.; Ivanilov, A.; Sviridov, Yu; Zaets, V.; Semak, A.

    2000-12-01

    Charge, fired strip multiplicity distributions for the induced signal were investigated for the 2 mm gap RPC operating with several tetrafluoroethane (C 2H 2F 4) based mixtures with variation of isobutane (iC 4H 10) and sulphur hexafluoride (SF 6) concentrations. Suppression of the large fast charges for the mixtures containing SF 6 in comparison with the binary C 2H 2F 4/iC 4H 10 mixture was confirmed. Exclusion of isobutane from the mixture with 2% of SF 6 does not change charge distributions.

  17. Student Interns' Socially Constructed Work Realities: Narrowing the Work Expectation-Reality Gap

    ERIC Educational Resources Information Center

    Barnett, Kathy

    2012-01-01

    New employees, including college students, often experience expectation-reality gaps about work, making the assimilation process more difficult for all. This qualitative study explores the role of the internship in narrowing the work expectation-reality gap. This article addresses two research questions: (a) What do students learn about work…

  18. Sterilization characteristics of dental instruments using oxygen plasma produced by narrow gap RF discharge

    NASA Astrophysics Data System (ADS)

    Sakai, Yasuhiro; Liu, Zhen; Goto, Masaaki; Hayashi, Nobuya

    2016-07-01

    Sterilization characteristics and material compatibility of low-pressure RF oxygen plasma sterilization method for dental instruments are investigated. Regarding the characteristics of the plasma sterilizer for dental instruments, it is small and can rapidly sterilize owing to a narrow gap discharge. Sterilization of vial-type biological indicators is achieved for the shortest treatment period of 40 min at an RF power of 80 W at a temperature of 70 °C. At a temperature lower than 60 °C, a sterilization period of 90 min is required using a water-cooled electrode. No surface modifications of dental instruments such as chemical composition and deterioration of fine crystals of a diamond bar were observed under a scanning electron microscope.

  19. Intergenerational Family Predictors of the Black-White Achievement Gap

    ERIC Educational Resources Information Center

    Mandara, Jelani; Varner, Fatima; Greene, Nereira; Richman, Scott

    2009-01-01

    The authors examined intergenerational family predictors of the Black-White achievement gap among 4,406 adolescents from the National Longitudinal Survey of Youth. An intergenerational model of the process by which family factors contribute to the achievement gap was also tested. The results showed that the ethnic gaps in socioeconomic status…

  20. Subgroup Achievement and Gap Trends: West Virginia, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in West Virginia for 2010. West Virginia administered new assessments in 2009, so comparisons to earlier years could not be made for the sake of discerning trends in subgroup achievement and gaps. Data on student achievement from earlier years are presented. (Contains 9 tables.)…

  1. Social Equity Theory and Racial-Ethnic Achievement Gaps

    ERIC Educational Resources Information Center

    McKown, Clark

    2013-01-01

    In the United States, racial-ethnic differences on tests of school readiness and academic achievement continue. A complete understanding of the origins of racial-ethnic achievement gaps is still lacking. This article describes social equity theory (SET), which proposes that racial-ethnic achievement gaps originate from two kinds of social process,…

  2. Closing the Math Achievement Gap: Institutions Find Success with MyMathLab

    ERIC Educational Resources Information Center

    Stewart, Pearl

    2012-01-01

    Institutions find success with Pearson Education's MyMathLab. The Department of Mathematical Sciences at the University of Memphis (UM) reported a narrowing of the achievement gap between Black and White students. According to the study conducted by UM professors and titled "The Effectiveness of Blended Instruction in Postsecondary General…

  3. The Role of the Superintendent in Closing the Achievement Gap in Diverse Small School Districts

    ERIC Educational Resources Information Center

    Wright, Howell, Jr.; Harris, Sandra

    2010-01-01

    The purpose of this qualitative, narrative study was to investigate the role of the superintendent in leading the district to be more culturally proficient, resulting in the narrowing of the achievement gap in culturally diverse small districts. Eight superintendents of small school districts were purposefully selected based on their district size…

  4. Plasmonically-enhanced mid-infrared photoluminescence in a metal/narrow-gap semiconductor structure

    NASA Astrophysics Data System (ADS)

    Lu, Pengqi; Cai, Chunfeng; Zhang, Bingpo; Liu, Bozhi; Wu, Huizhen; Bi, Gang; Si, Jianxiao

    2016-05-01

    We report the enhancement of the mid-infrared (MIR) luminescence intensity in a nanoscale metal/semiconductor structure by the coupling of surface plasmon polaritons (SPPs) with excitons in a narrow-gap semiconductor. The SPPs are efficiently excited by the total internal reflection photons at a metal/semiconductor interface. The intense electric field induced by SPPs, in turn, greatly changes the radiative recombination rates of the excitons generated by the pumping laser and thus the MIR luminescence intensity. The finding avails the understanding of fundamental science of SPs in narrow-gap semiconductors and the development of novel MIR devices.

  5. Education Watch: Achievement Gap Summary Tables.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    These summary tables focus on the state-by-state academic achievement of African American, Hispanic American, American Indian, Asian American, and white students. Data are presented on achievement gains by state (4th grade reading scale scores, 1992-1998; 8th grade science and scale scores, 1996-2000; 4th grade math scale scores, 1992-2000; and…

  6. Subgroup Achievement and Gap Trends: California

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), California students made gains across the board in reading at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. In math, there were some declines at the basic achievement level. In terms of…

  7. Subgroup Achievement and Gap Trends: Arizona

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Arizona students showed mostly gains in reading at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. In math, there were gains at all three achievement levels in grade 8 for these subgroups.…

  8. Subgroup Achievement and Gap Trends: New Mexico

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This year the Center on Education Policy (CEP) analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps…

  9. Subgroup Achievement and Gap Trends: Oklahoma

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This year the Center on Education Policy (CEP) analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps…

  10. Subgroup Achievement and Gap Trends: Oregon

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This year the Center on Education Policy (CEP) analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps…

  11. Boiling Visualization and Critical Heat Flux Phenomena In Narrow Rectangular Gap

    SciTech Connect

    J. J. Kim; Y. H. Kim; S. J. Kim; S. W. Noh; K. Y. Suh; J. Rempe; F. B. Cheung; S. B. Kim

    2004-12-01

    An experimental study was performed to investifate the pool boling critical hear flux (CHF) on one-dimensional inclined rectangular channels with narrow gaps by changing the orientation of a copper test heater assembly. In a pool of saturated water at atmospheric pressure, the test parameters include the gap sizes of 1,2,5, and 10 mm, andthe surface orientation angles from the downward facing position (180 degrees) to the vertical position (90 degress) respectively.

  12. Closing Achievement Gaps: Lessons from the Last 15 Years

    ERIC Educational Resources Information Center

    Murphy, Joseph

    2009-01-01

    At first glance, closing the achievement gap seems fairly straightforward. It is a difficult task to accomplish, but it does not seem an especially complex one to conceptualize. How educators look at achievement gaps will determine their success in reducing them. When designing interventions, the author suggests that educators need to remember the…

  13. The Academic Achievement Gap: The Suburban Challenge. CSR Connection.

    ERIC Educational Resources Information Center

    Alson, Allan

    Suburban schoolchildren of color, in the aggregate, do not perform as well as their white counterparts. In fact, the academic achievement gaps in many suburban communities are actually greater than those in urban school districts. This research brief looks at the achievement gap in suburban schools, offering preliminary answers to the following…

  14. The Importance of Physical Activity in Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Burton, Laura J.; VanHeest, Jaci L.

    2007-01-01

    The most significant concern within the US educational community is the academic achievement gap. Investigation of the achievement gap reveals that minority students across all levels of education are not meeting the same academic measures as their non-Hispanic White peers. In addition, a disproportionate number of minority children are identified…

  15. Parsing the Achievement Gap II. Policy Information Report

    ERIC Educational Resources Information Center

    Barton, Paul E.; Coley, Richard J.

    2009-01-01

    Gaps in school achievement among racial/ethnic groups and between students from different socioeconomic circumstances are well documented. They are wide and persistent, well known and widely acknowledged. This report focuses on the conditions and experiences that create and perpetuate achievement gaps. It is the second edition of the report…

  16. Closing Achievement Gaps: Revisiting Benjamin S. Bloom's "Learning for Mastery"

    ERIC Educational Resources Information Center

    Guskey, Thomas R.

    2007-01-01

    The problem of achievement gaps among different subgroups of students has been evident in education for many years. This manuscript revisits the work of renowned educator Benjamin S. Bloom, who saw reducing gaps in the achievement of various groups of students as a simple problem of reducing variation in student learning outcomes. Bloom observed…

  17. The Hispanic-Asian Achievement Gap in Elementary School

    ERIC Educational Resources Information Center

    Martinez, Lina Maria

    2012-01-01

    There is little research of Hispanic and Asian children's educational outcomes; in particular, the achievement gap between these two racial/ethnic groups has not been fully explored. The objective of this investigation is to analyze the Hispanic-Asian achievement gap in elementary school using the ECLS-K, a longitudinal nationally…

  18. Closing the Gap between Professional Development and Student Achievement

    ERIC Educational Resources Information Center

    Richards, Michelle K.

    2009-01-01

    Whenever there is a discussion on closing or bridging the achievement gap in education, one accurately reasons that the "gap" in question is among groups of students from various cultural and/or socioeconomic backgrounds. Stakeholders throughout academia, then, frantically search for solution(s)" to poor student achievement in America's ailing,…

  19. Superintendents' Responses to the Achievement Gap: An Ethical Critique.

    ERIC Educational Resources Information Center

    Sherman, Whitney H.; Grogan, Margaret

    2003-01-01

    Uses multidimensional ethical framework to critique 15 Virginia superintendents' responses to the achievement gap as measured by the Standards of Learning (SOL) tests. Questions majority of superintendents' readiness to deal with moral and ethical issues related to achievement gap. (Contains 24 references.) (PKP)

  20. Band Gap Narrowing and Widening of ZnO Nanostructures and Doped Materials.

    PubMed

    Kamarulzaman, Norlida; Kasim, Muhd Firdaus; Rusdi, Roshidah

    2015-12-01

    Band gap change in doped ZnO is an observed phenomenon that is very interesting from the fundamental point of view. This work is focused on the preparation of pure and single phase nanostructured ZnO and Cu as well as Mn-doped ZnO for the purpose of understanding the mechanisms of band gap narrowing in the materials. ZnO, Zn0.99Cu0.01O and Zn0.99Mn0.01O materials were prepared using a wet chemistry method, and X-ray diffraction (XRD) results showed that all samples were pure and single phase. UV-visible spectroscopy showed that materials in the nanostructured state exhibit band gap widening with respect to their micron state while for the doped compounds exhibited band gap narrowing both in the nano and micron states with respect to the pure ZnO materials. The degree of band gap change was dependent on the doped elements and crystallite size. X-ray photoelectron spectroscopy (XPS) revealed that there were shifts in the valence bands. From both UV-visible and XPS spectroscopy, it was found that the mechanism for band gap narrowing was due to the shifting of the valance band maximum and conduction band minimum of the materials. The mechanisms were different for different samples depending on the type of dopant and dimensional length scales of the crystallites. PMID:26319225

  1. Faculty Development to Address the Achievement Gap

    ERIC Educational Resources Information Center

    Gillian-Daniel, Donald L.; Kraemer, Sara B.

    2015-01-01

    Disparities in academic achievement between students who are under-represented minorities, the first in their families to go to college, and/or low income and their more privileged peers affects students from kindergarten through college. Inequities throughout their education, as well as other causes affect the ability of high school graduates to…

  2. Addressing Achievement Gaps with Psychological Interventions

    ERIC Educational Resources Information Center

    Yeager, David; Walton, Gregory; Cohen, Geoffrey L.

    2013-01-01

    Student psychology--how the classroom looks and feels from the perspective of the student--can powerfully affect motivation and learning, and experiments are increasingly showing that even brief interventions to change psychology can boost achievement over months or years. When paired with other structural reforms, social-psychological…

  3. Subgroup Achievement and Gap Trends: Maine

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Maine students had across-the-board gains. There were improvements in both reading and math at the basic, proficient and advanced levels for the subgroups large enough to count, which were white students, low income students, and boys and girls. Results on…

  4. Review of "Our Immense Achievement Gap"

    ERIC Educational Resources Information Center

    Eaton, Susan

    2012-01-01

    This report misrepresents and then criticizes recommendations from the Minnesota Department of Education, a think tank and two independent study groups, each of which recently encouraged particular voluntary efforts to reduce concentrated poverty and achieve racial and socioeconomic integration in schools and housing in Minnesota. In building its…

  5. Subgroup Achievement and Gap Trends: Arkansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Arkansas showed across-the-board gains--improvements in reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low income students, and boys and girls. The gains were quite large in most instances, especially at the…

  6. Subgroup Achievement and Gap Trends: Connecticut

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Connecticut students showed gains across the board in math--at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. In reading, there were gains at the basic and proficient levels, but a slight…

  7. Subgroup Achievement and Gap Trends: Colorado

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Colorado students showed gains in reading at the proficient level for racial/ethnic subgroups, low income students, and boys and girls. There were slight declines or flat trends for almost all subgroups at the advanced level in reading. In math, gains were…

  8. Subgroup Achievement and Gap Trends: Georgia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    Georgia has made some changes in its testing program in recent years. As a result, trend data were only available for reading in grades 4 and 8 from 2006 through 2009, and only at the proficient and advanced levels. In math, data were only available for the high school level from 2004 through 2009. Achievement data for low income students were…

  9. Is the California Special Education Achievement Gap Really Closing?

    ERIC Educational Resources Information Center

    Fearn, Emilene Johnson

    2012-01-01

    The achievement gains of California students with disabilities (SWDs) on the California Standards Test (CST)-English Language Arts have surpassed the achievement gains of students with no reported disabilities in recent years, and so the special education achievement gap seemed to be closing. However, the reported achievement for SWDs has not…

  10. Photography as a Means of Narrowing the Gap between Physics and Students

    ERIC Educational Resources Information Center

    Bagno, Esther; Eylon, Bat-Sheva; Levy, Smadar

    2007-01-01

    Many teachers would agree that not all their A-level students appreciate the beauty of physics or enjoy solving complex problems. In this article, we describe a photo-contest activity aimed at narrowing the gap between physics and students. The photo contest, involving both students and teachers, is guided by the National Center of Physics…

  11. NARROW-GAP POINT-TO-PLANE CORONA WITH HIGH VELOCITY FLOWS

    EPA Science Inventory

    The article discusses a mathematical model developed to describe a narrow- gap point- to- plane corona system used in the detoxification of chemical agents or their simulants, for which the degree of destruction depends on the strength of the electric field or electron energy. Na...

  12. Narrowing in on Educational Resources that Do Affect Student Achievement

    ERIC Educational Resources Information Center

    Archibald, Sarah

    2006-01-01

    In an era dominated by issues of school finance adequacy, it seems particularly important to provide evidence that, despite a number of claims to the contrary, educational resources are indeed positively related to improved student achievement. One of the hypotheses of this article is that expenditures per pupil must be disaggregated into more…

  13. Efficiency of silane gas generation in high-rate silicon etching by narrow-gap microwave hydrogen plasma

    NASA Astrophysics Data System (ADS)

    Ohmi, Hiromasa; Funaki, Takeshi; Kakiuchi, Hiroaki; Yasutake, Kiyoshi

    2016-01-01

    The silicon (Si) etching characteristics and the related efficiency of the etched Si to generate SiH4 gas in narrow-gap high-pressure microwave H2 plasma have been investigated. It was found that cooling of the Si sample is effective to obtain a high etching rate even under high pressure conditions, and the excess temperature increase of both the gas and Si sample can be suppressed even at an input power density of more than 250 W cm-3, probably because of the narrow plasma gap. The local etching depth monotonically increased with increasing H2 pressure and input plasma power, whereas the etching weight decreased with increasing H2 pressure. By simultaneously increasing the H2 pressure and input power, a maximum Si etching rate of 38 μm min-1 was achieved. This is considered to be related to the high H density generated in the narrow-gap microwave plasma at relatively low temperatures. The energy efficiency of Si etching and the utilization efficiency of the etched Si and H2 gas for SiH4 formation are discussed. Lower input power is favorable for high energy efficiency of Si etching. The Si utilization efficiency, which is defined as the molar ratio of generated SiH4 to etched Si, increases with decreasing average gas residence time in the plasma, whereas H2 utilization efficiency is independent of the gas residence time.

  14. Environmental effects on the electrical properties of narrow-gap carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Aspitarte, Lee; McCulley, Dan; Minot, Ethan

    Observations of single-walled carbon nanotubes (CNTs) with band gaps of 50 - 100 meV and diameters of approximately 2 nm pose an intriguing puzzle. The orthodox theory of CNTs predicts that such CNTs should have band gaps between 0 and 25 meV, yet these ``narrow-gap'' CNTs are routinely observed (band gaps in the range 50 - 100 meV). A possible explanation is that strong Coulomb interactions cause a Mott gap in nominally metallic CNTs (Deshpande et al., Science, 2009). To test this hypothesis, we have fabricated field-effect transistor devices from suspended narrow-gap CNTs. We have tested these devices in a variety of dielectric environments, including air, vacuum, TiO2 coatings, and molecular liquids such as oil, anisole, toluene, isopropanol, and water. In many cases we can relate changes in electrical properties to changes in electrostatic disorder, gate capacitance, mobility and band alignment. We will discuss the possibility of an interaction-driven effect that is changed by the dielectric environment.

  15. Practical Issues in Estimating Achievement Gaps from Coarsened Data

    ERIC Educational Resources Information Center

    Reardon, Sean F.; Ho, Andrew D.

    2015-01-01

    In an earlier paper, we presented methods for estimating achievement gaps when test scores are coarsened into a small number of ordered categories, preventing fine-grained distinctions between individual scores. We demonstrated that gaps can nonetheless be estimated with minimal bias across a broad range of simulated and real coarsened data…

  16. School Counselors: Closing Achievement Gaps and Writing Results Reports

    ERIC Educational Resources Information Center

    Hartline, Julie; Cobia, Debra

    2012-01-01

    Charged with closing the achievement gap for marginalized students, school counselors need to be able to identify gaps, develop interventions, evaluate effectiveness, and share results. This study examined 100 summary results reports submitted by school counselors after having received four days of training on the ASCA National Model. Findings…

  17. Testing of a Narrow Gap Detector designed for a sensitive X-ray polarimeter

    NASA Astrophysics Data System (ADS)

    Gilberto Almonte, Rafael; Hill, Joanne E.; Morris, David C.; Emmett, Thomas

    2015-01-01

    Time projection polarimeters are gas detectors where incident X-rays interact with a gas atom to produce a photoelectron whose direction is correlated with the polarization of the incident X-ray. By imaging the path of many photoelectrons the polarization of the incident X-ray can be determined.The next generation of time projection polarimeter incorporates a narrow gap detector to minimize the diffusion in the transfer gap between the gas electron multiplier and the readout strips. We report on the testing performed to bring the narrow-gap design to Technology Readiness Level (TRL)-6.TRL-6 testing included random and sine burst vibration tests and thermal cycling tests. In addition thermal shock tests and creep tests were performed to further demonstrate that the design would meet requirements, particularly flatness, throughout the life of a 2 year mission.The post-test inspection following the vibration testing showed no degradation or loss of flatness. Thermal Shock testing showed no indication that the extreme temperature had any effect on the detector. Creep testing showed no positive or negative trends in flatness. Thermal cycle testing also showed no change in detector behavior. All the requirements have been met and the narrow gap polarimeter is at TRL-6.

  18. Single-Crystal Semiconductors with Narrow Band Gaps for Solar Water Splitting.

    PubMed

    Wang, Tuo; Gong, Jinlong

    2015-09-01

    Solar water splitting provides a clean and renewable approach to produce hydrogen energy. In recent years, single-crystal semiconductors such as Si and InP with narrow band gaps have demonstrated excellent performance to drive the half reactions of water splitting through visible light due to their suitable band gaps and low bulk recombination. This Minireview describes recent research advances that successfully overcome the primary obstacles in using these semiconductors as photoelectrodes, including photocorrosion, sluggish reaction kinetics, low photovoltage, and unfavorable planar substrate surface. Surface modification strategies, such as surface protection, cocatalyst loading, surface energetics tuning, and surface texturization are highlighted as the solutions. PMID:26227831

  19. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

    SciTech Connect

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead to elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.

  20. Impurity-induced photoconductivity of narrow-gap Cadmium–Mercury–Telluride structures

    SciTech Connect

    Kozlov, D. V. Rumyantsev, V. V.; Morozov, S. V.; Kadykov, A. M.; Varavin, V. S.; Mikhailov, N. N.; Dvorestky, S. A.; Gavrilenko, V. I.; Teppe, F.

    2015-12-15

    The photoconductivity (PC) spectra of CdHgTe (MCT) solid solutions with a Cd fraction of 17 and 19% are measured. A simple model for calculating the states of doubly charged acceptors in MCT solid solutions, which makes it possible to describe satisfactorily the observed photoconductivity spectra, is proposed. The found lines in the photoconductivity spectra of narrow-gap MCT structures are associated with transitions between the states of both charged and neutral acceptor centers.

  1. Nanophotonic hybridization of narrow atomic cesium resonances and photonic stop gaps of opaline nanostructures

    NASA Astrophysics Data System (ADS)

    Harding, Philip J.; Pinkse, Pepijn W. H.; Mosk, Allard P.; Vos, Willem L.

    2015-01-01

    We study a hybrid system consisting of a narrow-band atomic optical resonance and the long-range periodic order of an opaline photonic nanostructure. To this end, we have infiltrated atomic cesium vapor in a thin silica opal photonic crystal. With increasing temperature, the frequencies of the opal's reflectivity peaks shift down by >20 % due to chemical reduction of the silica. Simultaneously, the photonic bands and gaps shift relative to the fixed near-infrared cesium D1 transitions. As a result the narrow atomic resonances with high finesse (ω /Δ ω =8 ×105 ) dramatically change shape from a usual dispersive shape at the blue edge of a stop gap, to an inverted dispersion line shape at the red edge of a stop gap. The line shape, amplitude, and off-resonance reflectivity are well modeled with a transfer-matrix model that includes the dispersion and absorption of Cs hyperfine transitions and the chemically reduced opal. An ensemble of atoms in a photonic crystal is an intriguing hybrid system that features narrow defectlike resonances with a strong dispersion, with potential applications in slow light, sensing, and optical memory.

  2. Achievement Gaps: An Examination of Differences in Student Achievement and Growth. The Full Report

    ERIC Educational Resources Information Center

    McCall, Martha S.; Hauser, Carl; Cronin, John; Kingsbury, G. Gage; Houser, Ronald

    2006-01-01

    The difference between the academic performance of poor students and wealthier students and between minority students and their non-minority peers is commonly known as the achievement gap. The current study examines the achievement gap using a large sample of students from a wide variety of school districts across the United States. It examines…

  3. Two Models of Learning and Achievement: An Explanation for the Achievement Gap?

    ERIC Educational Resources Information Center

    Yeh, Stuart S.

    2015-01-01

    Background/Context: Despite decades of research, the persistence of the gap in student achievement between disadvantaged minority students and their middle-class peers remains unexplained. Purpose/Objective: The purpose of the current article is to propose a new model of the achievement gap. Research Design: Data were analyzed from three…

  4. Closing the Achievement Gap: Views from Nine Schools.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Accountability.

    This study examined North Carolina schools serving large numbers of poor and minority students, emphasizing nine schools where black student achievement was especially high, where black students had made strong gains, or where the black-white achievement gap was closing faster than the state average. Between 1999-00, research teams visited each…

  5. Subgroup Achievement and Gap Trends: North Carolina, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in North Carolina for 2010. In grade 8 math (the only grade in which subgroup trends were analyzed by achievement level), North Carolina made gains across the board for all major subgroups at the basic-and-above, proficient-and-above, and advanced levels. Progress in narrowing…

  6. Social equity theory and racial-ethnic achievement gaps.

    PubMed

    McKown, Clark

    2013-01-01

    In the United States, racial-ethnic differences on tests of school readiness and academic achievement continue. A complete understanding of the origins of racial-ethnic achievement gaps is still lacking. This article describes social equity theory (SET), which proposes that racial-ethnic achievement gaps originate from two kinds of social process, direct and signal influences, that these two kinds of processes operate across developmental contexts, and that the kind of influence and the setting in which they are enacted change with age. Evidence supporting each of SET's key propositions is discussed in the context of a critical review of research on the Black-White achievement gap. Specific developmental hypotheses derived from SET are described, along with proposed standards of evidence for testing those hypotheses. PMID:23240908

  7. No Boy Left Behind: The Impact of Boy-Friendly Strategies on the Gender Writing Achievement Gap

    ERIC Educational Resources Information Center

    Sullivan, Janet Lee

    2012-01-01

    A study of the implementation of boy-friendly strategies for teaching writing was conducted in order to determine if the strategies would improve the writing achievement of fifth grade boys, thereby narrowing the gender achievement gap in writing. The strategies were categorized in four modalities: self-efficacy, perception/attitude, performance,…

  8. Band gap narrowing in BaTiO{sub 3} nanoparticles facilitated by multiple mechanisms

    SciTech Connect

    Ramakanth, S.; James Raju, K. C.

    2014-05-07

    In the present work, BaTiO{sub 3} nanoparticles of four different size ranges were prepared by sol-gel method. The optical band gap of these particles at some size ranges has come down to 2.53 eV from 3.2 eV, resulting in substantial increase in optical absorption by these ferroelectric nanoparticles making them potential candidates for light energy harvesting. XRD results show the presence of higher compressive strain in 23 nm and 54 nm size particles, they exhibit a higher band gap narrowing, whereas tensile strain is observed in 31 nm and 34 nm particles, and they do not show the marginal band gap narrowing. The 23 nm and 54 nm particles also show a coupling of free carriers to phonons by increasing the intensity of LO phonon mode at 715 cm{sup −1}. The higher surface charge density is expected in case of enhanced surface optical Raman modes (638 cm{sup −1}) contained in 31 and 34 nm size particles. In addition to this, the red shift in an LO mode Raman spectral line at 305 cm{sup −1} with decrease in particle size depicts the presence of phonon confinement in it. The enhanced optical absorption in 23 nm and 54 nm size particles with a narrowed band gap of 3 eV and 2.53 eV is due to exchange correlation interactions between the carriers present in these particles. In 31 nm and 34 nm range particles, the absorption got bleached exhibiting increased band gaps of 3.08 eV and 3.2 eV, respectively. It is due to filling up of conduction band resulting from weakening of exchange correlation interactions between the charge carriers. Hence, it is concluded that the band gap narrowing in the nanoparticles of average size 23 nm/54 nm is a consequence of multiple effects like strain, electron-phonon interaction, and exchange correlation interactions between the carriers which is subdued in some other size ranges like 31 nm/34 nm.

  9. Band gap narrowing in BaTiO3 nanoparticles facilitated by multiple mechanisms

    NASA Astrophysics Data System (ADS)

    Ramakanth, S.; James Raju, K. C.

    2014-05-01

    In the present work, BaTiO3 nanoparticles of four different size ranges were prepared by sol-gel method. The optical band gap of these particles at some size ranges has come down to 2.53 eV from 3.2 eV, resulting in substantial increase in optical absorption by these ferroelectric nanoparticles making them potential candidates for light energy harvesting. XRD results show the presence of higher compressive strain in 23 nm and 54 nm size particles, they exhibit a higher band gap narrowing, whereas tensile strain is observed in 31 nm and 34 nm particles, and they do not show the marginal band gap narrowing. The 23 nm and 54 nm particles also show a coupling of free carriers to phonons by increasing the intensity of LO phonon mode at 715 cm-1. The higher surface charge density is expected in case of enhanced surface optical Raman modes (638 cm-1) contained in 31 and 34 nm size particles. In addition to this, the red shift in an LO mode Raman spectral line at 305 cm-1 with decrease in particle size depicts the presence of phonon confinement in it. The enhanced optical absorption in 23 nm and 54 nm size particles with a narrowed band gap of 3 eV and 2.53 eV is due to exchange correlation interactions between the carriers present in these particles. In 31 nm and 34 nm range particles, the absorption got bleached exhibiting increased band gaps of 3.08 eV and 3.2 eV, respectively. It is due to filling up of conduction band resulting from weakening of exchange correlation interactions between the charge carriers. Hence, it is concluded that the band gap narrowing in the nanoparticles of average size 23 nm/54 nm is a consequence of multiple effects like strain, electron-phonon interaction, and exchange correlation interactions between the carriers which is subdued in some other size ranges like 31 nm/34 nm.

  10. Closing the Gap: An Overview. The Achievement Gap: An Overview. Info Brief. Number 44

    ERIC Educational Resources Information Center

    Poliakoff, Anne Rogers

    2006-01-01

    Persistent gaps between the academic achievements of different groups of children are thoroughly documented by the U.S. National Assessment of Educational Progress and other statistical analyses of state assessments, grades, course selection, and dropout rates. Despite improvements in some years, the gap endures as a consistent and disturbing…

  11. A Special Section on the Achievement Gap - Bridging the Achievement Gap: A Bridge Too Far?

    ERIC Educational Resources Information Center

    Mathis, William J.

    2005-01-01

    Half a century after Brown v. Board of Education, the great progress made in education can be marked, but the gap remains. Some federal and state political leaders have made gung-ho proclamations about leaving no child behind. Yet they send in too few troops, too lightly supported, and with too little planning. The vaunted "historic investments"…

  12. Preparation of the spacer for narrow electrode gap configuration in ionization-based gas sensor

    SciTech Connect

    Saheed, Mohamed Shuaib Mohamed; Mohamed, Norani Muti; Burhanudin, Zainal Arif

    2012-09-26

    Carbon nanotubes (CNTs) have started to be developed as the sensing element for ionization-based gas sensors due to the demand for improved sensitivity, selectivity, stability and other sensing properties beyond what can be offered by the conventional ones. Although these limitations have been overcome, the problems still remain with the conventional ionization-based gas sensors in that they are bulky and operating with large breakdown voltage and high temperature. Recent studies have shown that the breakdown voltage can be reduced by using nanostructured electrodes and narrow electrode gap. Nanostructured electrode in the form of aligned CNTs array with evenly distributed nanotips can enhance the linear electric field significantly. The later is attributed to the shorter conductivity path through narrow electrode gap. The paper presents the study on the design consideration in order to realize ionization based gas sensor using aligned carbon nanotubes array in an optimum sensor configuration with narrow electrode gap. Several deposition techniques were studied to deposit the spacer, the key component that can control the electrode gap. Plasma spray deposition, electron beam deposition and dry oxidation method were employed to obtain minimum film thickness around 32 {mu}m. For plasma spray method, sand blasting process is required in order to produce rough surface for strong bonding of the deposited film onto the surface. Film thickness, typically about 39 {mu}m can be obtained. For the electron beam deposition and dry oxidation, the film thickness is in the range of nanometers and thus unsuitable to produce the spacer. The deposited multilayer film consisting of copper, alumina and ferum on which CNTs array will be grown was found to be removed during the etching process. This is attributed to the high etching rate on the thin film which can be prevented by reducing the rate and having a thicker conductive copper film.

  13. Narrow band gap and enhanced thermoelectricity in FeSb2.

    PubMed

    Sun, Peijie; Oeschler, Niels; Johnsen, Simon; Iversen, Bo B; Steglich, Frank

    2010-01-28

    FeSb(2) was recently identified as a narrow-gap semiconductor with indications of strong electron-electron correlations. In this manuscript, we report on systematic thermoelectric investigation of a number of FeSb(2) single crystals with varying carrier concentrations, together with two isoelectronically substituted FeSb(2-x)As(x) samples (x = 0.01 and 0.03) and two reference compounds FeAs(2) and RuSb(2). Typical behaviour associated with narrow bands and narrow gaps is only confirmed for the FeSb(2) and the FeSb(2-x)As(x) samples. The maximum absolute thermopower of FeSb(2) spans from 10 to 45 mV/K at around 10 K, greatly exceeding that of both FeAs(2) and RuSb(2). The relation between the carrier concentration and the maximum thermopower value is in approximate agreement with theoretical predictions of the electron-diffusion contribution which, however, requires an enhancement factor larger than 30. The isoelectronic substitution leads to a reduction of the thermal conductivity, but the charge-carrier mobility is also largely reduced due to doping-induced crystallographic defects or impurities. In combination with the high charge-carrier mobility and the enhanced thermoelectricity, FeSb(2) represents a promising candidate for thermoelectric cooling applications at cryogenic temperatures. PMID:20066185

  14. An Experimental Study of Critical Heat Flux in Narrow Gap With Two-Dimensional Slices

    SciTech Connect

    Yong Hoon Kim; Suh, Kune Y.; Rae Joon Park; San Baek Kim; Hee Dong Kim

    2002-07-01

    A cooling mechanism due to boiling in a gap between the debris crust and the reactor pressure vessel (RPV) wall was proposed for the TMI-2 reactor accident analysis. If there is enough heat transfer through the gap to cool the outer surface of the debris and the inner surface of the wall, the RPV wall may preserve its integrity during a severe core melt accident. If the heat removal through gap cooling relative to the counter-current flow limitation (CCFL) is pronounced, the safety margin of the reactor can be far greater than what had been previously known in the severe accident management arena. Should a severe accident take place, the RPV integrity will be maintained because of the inherent nature of degraded core coolability inside the lower head due to boiling in a narrow gap between the debris crust and the RPV wall. As a defense-in-depth measure, the heat removal capability by gap cooling coupled with external cooling can be examined for the Korean Standard Nuclear Power Plant (KSNPP) and the Advanced Power Reactor 1400 MWe (APR1400) in light of the TMI-2 vessel survival. A number of studies were carried out to investigate the complex heat transfer mechanisms for the debris cooling in the lower plenum. However, these heat transfer mechanisms have not been clearly understood yet. The CHFG (Critical Heat Flux in Gap) experiments at KAERI were carried out to develop the critical heat flux (CHF) correlation in a hemispherical gap, which is the upper limit of the heat transfer. According to the CHFG experiments performed with a pool boiling condition, the CHF in a parallel gap was reduced by 1/30 compared with the value measured in the open pool boiling condition. The correlation developed from the CHFG experiment is based on the fact that the CHF in a hemispherical gap is governed by the CCFL and a Kutateladze type CCFL parameter correlates CCFL data well in hemispherical gap geometry. However, the results of the CHFG experiments appear to be limited in their

  15. Shear Stress induced Stretching of Red Blood Cells by Oscillating Bubbles within a Narrow Gap

    NASA Astrophysics Data System (ADS)

    Li, Fenfang; Mohammadzadeh, Milad; Ohl, Claus-Dieter; Claus-Dieter Ohl Team

    2013-11-01

    The flow pattern, especially the boundary layer caused by the expanding/contracting bubble in a narrow gap (15 μm) and the resultant stretching of red blood cells is investigated in this work. High speed recordings show that a red blood cell (biconcave shape, thickness of 1-2 μm) can be elongated to five times its original length by a laser-induced cavitation bubble within the narrow gap. However, flexible cancer cells in suspension (RKO, spherical shape, diameter of 10-15 μm) are hardly elongated under the same experimental condition. We hypothesize that the shear stress at the boundary layer is crucial for this elongation to occur. Therefore, in order to resolve the related fluid dynamics, we conducted numerical simulations using the finite element method (Fluent). The rapidly expanding/contracting vapor bubble is successfully modeled by employing viscosity and surface tension. The transient pressure inside the bubble and the velocity profile of the flow is obtained. We observe strong shear near the upper and lower boundary during the bubble oscillation. The flow fields are compared with analytical solutions to transient and pulsating flows in 2D. In the experiment the red blood cells sit within the lower boundary layer, thus are probably elongated by this strong shear flow. In contrast, the spherical cancer cells are of comparable size to the gap height so that they are lesser affected by this boundary layer flow.

  16. Closing the Educational Achievement Gap between Blacks and Whites: Nobody Wants to Be Black

    ERIC Educational Resources Information Center

    Scott, Austin L.; Kronick, Robert

    2006-01-01

    This research study attempts to explain the educational achievement gap between blacks and whites, the factors that cause the achievement gap, the consequences of the achievement gap for the black race, and possible solutions to the achievement gap. The data collected for this study has shown that the educational achievement gap between blacks and…

  17. An Academic Curriculum Will Close the Academic Achievement Gap

    ERIC Educational Resources Information Center

    Palumbo, Anthony; Kramer-Vida, Louisa

    2012-01-01

    America's unyielding academic achievement gap has been a national priority for a long time; yet, some schools have succeeded with academically disadvantaged youth. Usually, these institutions embrace a culture of success and follow an academic curriculum that is grounded in core knowledge and scholastic vocabulary. Academically disadvantaged…

  18. Using Student-Involved Classroom Assessment to Close Achievement Gaps

    ERIC Educational Resources Information Center

    Stiggins, Rick; Chappuis, Jan

    2005-01-01

    The authors argue that the failure of 60 years of total reliance on assessment via standardized tests to help reduce achievement score gaps must compel us to rethink the role of assessment in this endeavor. They advocate rebalancing assessment priorities to bring classroom assessment into the equation. Evidence gathered over decades from around…

  19. A Pre-Kindergarten Achievement Gap? Scope and Implications

    ERIC Educational Resources Information Center

    Wang, Aubrey H.

    2008-01-01

    This study examined the degree to which achievement gaps existed among different ethnic and racial groups before kindergarten entry. Using published data on the Early Childhood Longitudinal Study-Birth Cohort, this study found statistically significant differences in language knowledge and skills, literacy knowledge and skills, and mathematics…

  20. Closing the Achievement Gap: Rural Schools. CSR Connection.

    ERIC Educational Resources Information Center

    Williams, Doris Terry

    Twenty percent of the children enrolled in rural and small-town schools are non-Caucasian, children of color. As in nonrural schools, rural schools have yet to close the achievement gap across various racial and economic subgroups of this diverse population. Overall, rural students perform as well as or better than their nonrural peers on…

  1. Minding the Achievement Gap One Classroom at a Time

    ERIC Educational Resources Information Center

    Pollock, Jane E.; Ford, Sharon; Black, Margaret M.

    2012-01-01

    Do teachers have the power to close achievement gaps? Here's a book that boldly claims they do and lays out a blueprint for how to do something now to help students who are falling short of standards. Regardless of the student population you need to address--English language learners, special education, or just the unmotivated and hard to…

  2. Subgroup Achievement and Gap Trends: South Dakota, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in South Dakota for 2010. South Dakota's demographic profile is such that, with the exception of Native American students, there are fewer than 500 students in the racial/ethnic subgroups at the various grade levels, and therefore these groups are too small to count for this…

  3. Expanding METCO and Closing Achievement Gaps. White Paper No. 129

    ERIC Educational Resources Information Center

    Apfelbaum, Katherine; Ardon, Ken

    2015-01-01

    School systems around the United States are heavily segregated by income and race. At the same time, an achievement gap between white and nonwhite students persists despite many efforts to close it. Against this background, in this white paper the authors explore the history and successes of the Metropolitan Council for Educational Opportunity…

  4. Self-Regulation and the Income-Achievement Gap

    ERIC Educational Resources Information Center

    Evans, Gary W.; Rosenbaum, Jennifer

    2008-01-01

    The pervasive income-related achievement gap among children has been partially explained by parental investments. Wealthier parents provide more cognitively enriched environments (e.g., books, informal learning opportunities such as music lessons) and converse more with their children relative to low-income parents. However parental investment…

  5. Creating Quality Choices: Charters. Closing the Achievement Gap Series

    ERIC Educational Resources Information Center

    Read, Tory

    2008-01-01

    The "Closing the Achievement Gap" series explores the Casey Foundation's education investments and presents stories, results, and lessons learned. This publication presents stories about two successful charter efforts and Foundation contributions. Contributions include: (1) Supporting a variety of activities and programs; (2) Financial support for…

  6. Helping Students Succeed: Communities Confront the Achievement Gap

    ERIC Educational Resources Information Center

    Flono, Fannie

    2010-01-01

    In 2007, the Kettering Foundation launched a nationwide, two-year research project to learn what people in communities across the nation think about the achievement gap--and what roles they see for themselves in helping young people succeed academically. The community forums, which drew more than 3,200 participants nationwide, spotlighted elements…

  7. Social Identity and Achievement Gaps: Evidence from an Affirmation Intervention

    ERIC Educational Resources Information Center

    Dee, Thomas S.

    2015-01-01

    One provocative explanation for the continued persistence of minority achievement gaps involves the performance-dampening anxiety thought to be experienced by minority students in highly evaluative settings (i.e., "stereotype threat"). Recent field-experimental studies suggest that modest, low-cost "buffering" interventions…

  8. Subgroup Achievement and Gap Trends: New Hampshire, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in New Hampshire for 2010. New Hampshire's demographic profile is such that, with the exception of Latino students at the elementary level, there are fewer than 500 students in the racial/ethnic subgroups at the various grade levels, and therefore these groups are too small to…

  9. Broadening of effective photonic band gaps in biological chiral structures: From intrinsic narrow band gaps to broad band reflection spectra

    NASA Astrophysics Data System (ADS)

    Vargas, W. E.; Hernández-Jiménez, M.; Libby, E.; Azofeifa, D. E.; Solis, Á.; Barboza-Aguilar, C.

    2015-09-01

    Under normal illumination with non-polarized light, reflection spectra of the cuticle of golden-like and red Chrysina aurigans scarabs show a structured broad band of left-handed circularly polarized light. The polarization of the reflected light is attributed to a Bouligand-type left-handed chiral structure found through the scarab's cuticle. By considering these twisted structures as one-dimensional photonic crystals, a novel approach is developed from the dispersion relation of circularly polarized electromagnetic waves traveling through chiral media, to show how the broad band characterizing these spectra arises from an intrinsic narrow photonic band gap whose spectral position moves through visible and near-infrared wavelengths.

  10. A "Gap-Gazing" Fetish in Mathematics Education? Problematizing Research on the Achievement Gap

    ERIC Educational Resources Information Center

    Gutierrez, Rochelle

    2008-01-01

    A substantial amount of research in mathematics education seeks to document disparities in achievement between middle-class White students and students who are Black, Latina/Latino, First Nations, English language learners, or working class. I outline the dangers in maintaining an achievement-gap focus. These dangers include offering little more…

  11. Model based studies of some optical and electronic properties of narrow and wide gap materials

    NASA Astrophysics Data System (ADS)

    Ravindra, N. M.; Kumar, K. S.; Srivastava, V. K.; Bhardwaj, R. P.

    1981-11-01

    Studies are reported concerning the optical and electronic properties of narrow and wide gap materials in the groups IV, V, VI, III-V, II-VI, I-VII, IV-VI, and IV-IV, with emphasis on the high-frequency dielectric constant and its related properties. The relevance of this work to solar cells is discussed, and a comparative assessment of the models proposed by Penn (1962), Van Vechten (1969), Breckenridge et al. (1974) and Grimes and Cowley (1975) is presented. It is found that, although all of the models give adequate estimates of the Penn gap, none of them are universally applicable. In addition, studies are presented of the temperature and pressure dependence of the Penn and energy gaps and the high frequency dielectric constant, followed by an evaluation of the electron-phonon contribution to the total temperature dependence of the energy gap and the refractive index. The inverse square law governing the variation of deformation potential with the lattice parameter is found to be valid for a large number of semiconductors.

  12. Narrowing the transmission gap: A synthesis of three decades of research on intergenerational transmission of attachment.

    PubMed

    Verhage, Marije L; Schuengel, Carlo; Madigan, Sheri; Fearon, R M Pasco; Oosterman, Mirjam; Cassibba, Rosalinda; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H

    2016-04-01

    Twenty years ago, meta-analytic results (k = 19) confirmed the association between caregiver attachment representations and child-caregiver attachment (Van IJzendoorn, 1995). A test of caregiver sensitivity as the mechanism behind this intergenerational transmission showed an intriguing "transmission gap." Since then, the intergenerational transmission of attachment and the transmission gap have been studied extensively, and now extend to diverse populations from all over the globe. Two decades later, the current review revisited the effect sizes of intergenerational transmission, the heterogeneity of the transmission effects, and the size of the transmission gap. Analyses were carried out with a total of 95 samples (total N = 4,819). All analyses confirmed intergenerational transmission of attachment, with larger effect sizes for secure-autonomous transmission (r = .31) than for unresolved transmission (r = .21), albeit with significantly smaller effect sizes than 2 decades earlier (r = .47 and r = .31, respectively). Effect sizes were moderated by risk status of the sample, biological relatedness of child-caregiver dyads, and age of the children. Multivariate moderator analyses showed that unpublished and more recent studies had smaller effect sizes than published and older studies. Path analyses showed that the transmission could not be fully explained by caregiver sensitivity, with more recent studies narrowing but not bridging the "transmission gap." Implications for attachment theory as well as future directions for research are discussed. PMID:26653864

  13. Growth of semiconducting single-wall carbon nanotubes with a narrow band-gap distribution

    PubMed Central

    Zhang, Feng; Hou, Peng-Xiang; Liu, Chang; Wang, Bing-Wei; Jiang, Hua; Chen, Mao-Lin; Sun, Dong-Ming; Li, Jin-Cheng; Cong, Hong-Tao; Kauppinen, Esko I.; Cheng, Hui-Ming

    2016-01-01

    The growth of high-quality semiconducting single-wall carbon nanotubes with a narrow band-gap distribution is crucial for the fabrication of high-performance electronic devices. However, the single-wall carbon nanotubes grown from traditional metal catalysts usually have diversified structures and properties. Here we design and prepare an acorn-like, partially carbon-coated cobalt nanoparticle catalyst with a uniform size and structure by the thermal reduction of a [Co(CN)6]3− precursor adsorbed on a self-assembled block copolymer nanodomain. The inner cobalt nanoparticle functions as active catalytic phase for carbon nanotube growth, whereas the outer carbon layer prevents the aggregation of cobalt nanoparticles and ensures a perpendicular growth mode. The grown single-wall carbon nanotubes have a very narrow diameter distribution centred at 1.7 nm and a high semiconducting content of >95%. These semiconducting single-wall carbon nanotubes have a very small band-gap difference of ∼0.08 eV and show excellent thin-film transistor performance. PMID:27025784

  14. Hydrogen atom density in narrow-gap microwave hydrogen plasma determined by calorimetry

    NASA Astrophysics Data System (ADS)

    Yamada, Takahiro; Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi

    2016-02-01

    The density of hydrogen (H) atoms in the narrow-gap microwave hydrogen plasma generated under high-pressure conditions is expected to be very high because of the high input power density of the order of 104 W/cm3. For measuring the H atom density in such a high-pressure and high-density plasma, power-balance calorimetry is suited since a sufficient signal to noise ratio is expected. In this study, H atom density in the narrow-gap microwave hydrogen plasma has been determined by the power-balance calorimetry. The effective input power to the plasma is balanced with the sum of the powers related to the out-going energy per unit time from the plasma region via heat conduction, outflow of high-energy particles, and radiation. These powers can be estimated by simple temperature measurements using thermocouples and optical emission spectroscopy. From the power-balance data, the dissociation fraction of H2 molecules is determined, and the obtained maximum H atom density is (1.3 ± 0.2) × 1018 cm-3. It is found that the H atom density increases monotonically with increasing the energy invested per one H2 molecule within a constant plasma volume.

  15. Infrared spectroscopy of narrow gap donor-acceptor polymer-based ambipolar transistors

    NASA Astrophysics Data System (ADS)

    Khatib, Omar; Yuen, Jonathan; Wilson, Jim; Kumar, Rajeev; di Ventra, Massimiliano; Heeger, Alan; Basov, Dimitri

    2013-03-01

    Donor-acceptor (D-A) copolymers have recently emerged as versatile materials for use in a large variety of device applications. Specifically, these systems possess extremely narrow band gaps, enabling ambipolar charge transport when integrated in solution-processed organic field-effect transistors (OFETs). However, the fundamentals of electronic transport in this class of materials remain unexplored. We present a systematic investigation of ambipolar charge injection in a family of narrow-gap D-A conjugated polymers based on benzobisthiadiazole (BBT) using infrared (IR) spectroscopy. We observe a significant modification of the absorption edge in polymer-based OFETs under the applied electric field. The absorption edge reveals hardening under electron injection and softening under hole injection. Additionally, we register localized vibrational resonances associated with injected charges. Our findings indicate a significant self-doping of holes that is modified by charge injection. Observations of both electron and hole transport with relatively high carrier mobility strongly suggest an inhomogeneous, phase-separated conducting polymer.

  16. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

    DOE PAGESBeta

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead tomore » elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.« less

  17. Exploring the Achievement Gap between White and Minority Students in Texas: A Comparison of the 1996 and 2000 NAEP and TAAS Eighth Grade Mathematics Test Results.

    ERIC Educational Resources Information Center

    Linton, Thomas H.; Kester, Donald

    2003-01-01

    Compared scores for Texas eighth graders on the Texas Assessment of Academic Skills (TAAS) and National Assessment of Educational Progress (NAEP) to study the achievement gap in mathematics in 1996 and 2000. Results show the likelihood of a ceiling effect impacting students' TAAS scores that created the illusion the achievement gap had narrowed.…

  18. Examining the Achievement Gap: The Effectiveness of African American Teachers Instructing African American Students in Kansas City Public Schools

    ERIC Educational Resources Information Center

    Campbell, Judith Jordan

    2013-01-01

    Over several years the American public educational system has failed to address one of the most infuriating problems faced by our nation, narrowing the achievement gap in urban districts with urban learners. Historically, minority students have not paralleled the academic performance of their White counterparts. This holds true with standardized…

  19. An Agenda for the Future: Closing the Achievement Gap for Underrepresented Groups in Gifted and Talented Education

    ERIC Educational Resources Information Center

    Lockwood, Anne Turnbaugh

    2007-01-01

    To identify a future research agenda with the goal of narrowing the achievement gap between underrepresented groups and their peers in gifted and talented education, The National Research Center on the Gifted and Talented (NRC/GT) at the University of Connecticut convened a Needs Assessment Conference in January 2005 and commissioned four…

  20. Developing A New Test Stand For Lifetime Measurements Using A Narrow Gap Detector

    NASA Astrophysics Data System (ADS)

    Tuitt, Omani; Hill, Joanne E.; Jahoda, Keith; Morris, David C.

    2016-01-01

    The University of the Virgin Islands (UVI) recently won a proposal "The First Four-Year Physics and Astronomy Degree at the University of the Virgin Islands; A new Era in Caribbean Participation in NASA Science" in collaboration with NASA Goddard Space Flight Center (GSFC). The proposal included building a detector life-test chamber at UVI to support the degree program as well as assist NASA by running tests on detector components and reporting the results.The team at GSFC is developing X-ray polarimeters that can be used in detecting and imaging astrophysical sources such as black holes and neutron stars. The purpose of our research is to understand the effects that the degradation of gas has on the performance of the detectors. The current generation of time projection polarimeter incorporates a narrow gap detector assembled with epoxy. The addition of the epoxy allows a smaller gap with the minimal amount of changes from the original design, enhancing the performance of the detectors.With the use of epoxy, lifetime measurements have to be made to see how the epoxy detectors compared to previous iterations. We have been studying the effects on the narrow gap detector in the Mahaffey chamber in order to determine whether the epoxy affects the cleanliness of the gas. Tests have been conducted with a residual gas analyzer (RGA) in order to monitor the cleanliness of the gas inside of the Mahaffey chamber while being baked out. Results show that the detector is in fact getting cleaner as time progresses. The plan is to recreate a detector that meets the performance criteria for 2 years and has minimal degradation.

  1. Why Closing the Research-Practice Gap Is Critical to Closing Student Achievement Gaps

    ERIC Educational Resources Information Center

    Cooper, Laura A.

    2007-01-01

    Discussions of the research-practice gap often assume that K-12 educators are uninterested in or even derisive about the value of research for improving student learning. The work of K-12 educators in the Minority Student Achievement Network (MSAN) counters this conventional wisdom. This article provides evidence that MSAN educators not only value…

  2. Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 2. Overview).

    SciTech Connect

    Fujita,E.; Khalifah, P.; Lymar, S.; Muckerman, J.T.; Rodriguez, J.

    2008-03-18

    The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.

  3. H-tailored surface conductivity in narrow band gap In(AsN)

    SciTech Connect

    Velichko, A. V. E-mail: anton.velychko@nottingham.ac.uk; Patanè, A. E-mail: anton.velychko@nottingham.ac.uk; Makarovsky, O.; Capizzi, M.; Polimeni, A.; Sandall, I. C.; Tan, C. H.; Giubertoni, D.; Krier, A.; Zhuang, Q.

    2015-01-12

    We show that the n-type conductivity of the narrow band gap In(AsN) alloy can be increased within a thin (∼100 nm) channel below the surface by the controlled incorporation of H-atoms. This channel has a large electron sheet density of ∼10{sup 18 }m{sup −2} and a high electron mobility (μ > 0.1 m{sup 2}V{sup −1}s{sup −1} at low and room temperature). For a fixed dose of impinging H-atoms, its width decreases with the increase in concentration of N-atoms that act as H-traps thus forming N-H donor complexes near the surface.

  4. Band gap narrowing in zinc oxide-based semiconductor thin films

    SciTech Connect

    Kumar, Jitendra E-mail: akrsri@gmail.com; Kumar Srivastava, Amit E-mail: akrsri@gmail.com

    2014-04-07

    A simple expression is proposed for the band gap narrowing (or shrinkage) in semiconductors using optical absorption measurements of spin coated 1 at. % Ga-doped ZnO (with additional 0–1.5 at. % zinc species) thin films as ΔE{sub BGN} = Bn{sup 1/3} [1 − (n{sub c}/n){sup 1/3}], where B is the fitting parameter, n is carrier concentration, and n{sub c} is the critical density required for shrinkage onset. Its uniqueness lies in not only describing variation of ΔE{sub BGN} correctly but also allowing deduction of n{sub c} automatically for several M-doped ZnO (M: Ga, Al, In, B, Mo) systems. The physical significance of the term [1 − (n{sub c}/n){sup 1/3}] is discussed in terms of carrier separation.

  5. Photoinduced phase transitions in narrow-gap Mott insulators: The case of VO2

    NASA Astrophysics Data System (ADS)

    He, Zhuoran; Millis, Andrew J.

    2016-03-01

    We study the nonequilibrium dynamics of photoexcited electrons in the narrow-gap Mott insulator VO2. The initial stages of relaxation are treated using a quantum Boltzmann equation methodology, which reveals a rapid (˜femtosecond time scale) relaxation to a pseudothermal state characterized by a few parameters that vary slowly in time. The long-time limit is then studied by a Hartree-Fock methodology, which reveals the possibility of nonequilibrium excitation to a new metastable M1 metal phase that is qualitatively consistent with a recent experiment. The general physical picture of photoexcitation driving a correlated electron system to a new state that is not accessible in equilibrium may be applicable in similar materials.

  6. Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 1. Overview).

    SciTech Connect

    Fujita,E.; Khalifah, P.; Lymar, S.; Muckerman, J.T.; Rodgriguez, J.

    2008-03-18

    The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.

  7. Green digital signage using nanoparticle embedded narrow-gap field sequential TN-LCDs

    NASA Astrophysics Data System (ADS)

    Kobayashi, Shunsuke; Shiraishi, Yukihide; Sawai, Hiroya; Toshima, Naoki; Okita, Masaya; Takeuchi, Kiyofumi; Takatsu, Haruyoshi

    2012-03-01

    We have fabricated field sequential color (FSC)-LCDs using cells and modules of narrow-gap TN-LCDs with and without doping the nanoparticles of PCyD-ZrO2 and AF-SiO2. It is shown that the FSC-LCD exhibits a high optical efficiency of OE=4.5 that is defined as OE=[Luminance]/[W/m2]=(cd/W). This figure may provide us a good reference or to clear the Energy Star Program Version 5-3 that issues a guideline: LCD with 50 inch on the diagonal consumes the energy of 108W. Through this research it is claimed that our FSC=LCD may be a novel green digital signage.

  8. Magneto-optical studies of magnetic and non-magnetic narrow-gap semiconductors

    NASA Astrophysics Data System (ADS)

    Khodaparast, Giti

    2005-03-01

    In light of the growing interest in spin-related phenomena and devices, there is now renewed interest in the science and engineering of narrow gap semiconductors. Narrow gap semiconductors (NGS) offer many unique features such as small effective masses, high intrinsic mobilities, large effective g- factors, and large spin-orbit coupling effects. This talk will discuss our recent magneto-optical studies on InSb quantum wells (QWs) and InMnAs ferromagnetic heterostructures. In InSb QWs, we observe spin-resolved cyclotron resonance (CR) caused by the non- parabolicity in conduction band and electron spin resonance in symmetric and asymmetric confinement potentials. The asymmetric wells exhibit a strong deviation in behavior from the symmetric wells at low magnetic fields with far more spin splitting than expected from the bulk g-factor of InSb. In InMnAs/GaSb we observe light and heavy hole CR peaks which demonstrate the existence of delocalized p-like carriers. In addition, In order to increase our understanding of the dynamics of carriers and spins, we performed time resolved measurements such as time- resolved CR spectroscopy on undoped InSb QWs and time-resolved magneto-optical Kerr effect on InMnAs/GaSb. Our results are important for understanding the electronic and magnetic states in NGS. This work was performed in collaboration with M. B. Santos and R. E. Doezema at the Univ. of Oklahoma, J. Wang and J. Kono at Rice Univ., H. Munekata at Tokyo Institute of Technology, C. J. Stanton at the Univ. of Florida, and Y. H. Matsuda and N. Miura at the Univ. of Tokyo.

  9. Involving service users in interprofessional education narrowing the gap between theory and practice.

    PubMed

    Cooper, Helen; Spencer-Dawe, Eileen

    2006-12-01

    Calls for greater collaboration between professionals in health and social care have led to pressures to move toward interprofessional education (IPE) at both pre- and post-registration levels. Whilst this move has evolved out of "common sense" demands, such a multiple systems approach to education does not fit easily into existing traditional educational frameworks and there is, as yet, no proven theoretical framework to guide its development. A research study of an IPE intervention at the University of Liverpool in the UK drew on complexity theory to conceptualize the intervention and to evaluate its impact on a group of approximately 500 students studying physiotherapy, medicine, occupational therapy, nursing and social work. The intervention blended a multidisciplinary (non-interactive) plenary with self-directed e-learning and a series of interdisciplinary (interactive) workshops. Two evaluations took place: the first when the workshops were facilitated by trained practitioners; the second when the practitioners co-facilitated with trained service users. This paper reports findings from the second evaluation which focused on narrowing the gap between theory and practice. A multi-stakeholder evaluation was used including: students' reflective narratives, a focus group with practitioners and individual semi-structured interviews with service users. Findings showed that service users can make an important contribution to IPE for health and social care students in the early stages of their training. By exposure to a service user perspective, first year students can begin to learn and apply the principles of team work, to place the service user at the centre of the care process, to make connections between theory and "real life" experiences, and to narrow the gap between theory and practice. Findings also revealed benefits for facilitators and service users. PMID:17095439

  10. Ring-bursting behavior en route to turbulence in narrow-gap Taylor-Couette flows.

    PubMed

    Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng

    2015-11-01

    We investigate the Taylor-Couette system where the radius ratio is close to unity. Systematically increasing the Reynolds number, we observe a number of previously known transitions, such as one from the classical Taylor vortex flow (TVF) to wavy vortex flow (WVF) and the transition to fully developed turbulence. Prior to the onset of turbulence, we observe intermittent bursting patterns of localized turbulent patches, confirming the experimentally observed pattern of very short wavelength bursts (VSWBs). A striking finding is that, for a Reynolds number larger than that for the onset of VSWBs, a new type of intermittently bursting behavior emerges: patterns of azimuthally closed rings of various orders. We call them ring-bursting patterns, which surround the cylinder completely but remain localized and separated in the axial direction through nonturbulent wavy structures. We employ a number of quantitative measures including the cross-flow energy to characterize the ring-bursting patterns and to distinguish them from the background flow. These patterns are interesting because they do not occur in the wide-gap Taylor-Couette flow systems. The narrow-gap regime is less studied but certainly deserves further attention to gain deeper insights into complex flow dynamics in fluids. PMID:26651790

  11. Ring-bursting behavior en route to turbulence in narrow-gap Taylor-Couette flows

    NASA Astrophysics Data System (ADS)

    Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng

    2015-11-01

    We investigate the Taylor-Couette system where the radius ratio is close to unity. Systematically increasing the Reynolds number, we observe a number of previously known transitions, such as one from the classical Taylor vortex flow (TVF) to wavy vortex flow (WVF) and the transition to fully developed turbulence. Prior to the onset of turbulence, we observe intermittent bursting patterns of localized turbulent patches, confirming the experimentally observed pattern of very short wavelength bursts (VSWBs). A striking finding is that, for a Reynolds number larger than that for the onset of VSWBs, a new type of intermittently bursting behavior emerges: patterns of azimuthally closed rings of various orders. We call them ring-bursting patterns, which surround the cylinder completely but remain localized and separated in the axial direction through nonturbulent wavy structures. We employ a number of quantitative measures including the cross-flow energy to characterize the ring-bursting patterns and to distinguish them from the background flow. These patterns are interesting because they do not occur in the wide-gap Taylor-Couette flow systems. The narrow-gap regime is less studied but certainly deserves further attention to gain deeper insights into complex flow dynamics in fluids.

  12. The Achievement Gap: Factors That Influenced the Achievement of Successful Black Students

    ERIC Educational Resources Information Center

    Morton, Kwame R., Sr.

    2011-01-01

    The academic underperformance of Black students when compared to their White peers has confounded educators nationwide. This discrepancy in academic performance commonly referred to as the achievement gap has become a national crisis which has led to one of the most significant educational reforms undertaken in the United States of America in the…

  13. WFH: closing the global gap--achieving optimal care.

    PubMed

    Skinner, Mark W

    2012-07-01

    For 50 years, the World Federation of Hemophilia (WFH) has been working globally to close the gap in care and to achieve Treatment for All patients, men and women, with haemophilia and other inherited bleeding disorders, regardless of where they might live. The WFH estimates that more than one in 1000 men and women has a bleeding disorder equating to 6,900,000 worldwide. To close the gap in care between developed and developing nations a continued focus on the successful strategies deployed heretofore will be required. However, in response to the rapid advances in treatment and emerging therapeutic advances on the horizon it will also require fresh approaches and renewed strategic thinking. It is difficult to predict what each therapeutic advance on the horizon will mean for the future, but there is no doubt that we are in a golden age of research and development, which has the prospect of revolutionizing treatment once again. An improved understanding of "optimal" treatment is fundamental to the continued evolution of global care. The challenges of answering government and payer demands for evidence-based medicine, and cost justification for the introduction and enhancement of treatment, are ever-present and growing. To sustain and improve care it is critical to build the body of outcome data for individual patients, within haemophilia treatment centers (HTCs), nationally, regionally and globally. Emerging therapeutic advances (longer half-life therapies and gene transfer) should not be justified or brought to market based only on the notion that they will be economically more affordable, although that may be the case, but rather more importantly that they will be therapeutically more advantageous. Improvements in treatment adherence, reductions in bleeding frequency (including microhemorrhages), better management of trough levels, and improved health outcomes (including quality of life) should be the foremost considerations. As part of a new WFH strategic plan

  14. Magneto-optical transitions between subbands with different quantum numbers in narrow gap HgTe-CdTe superlattices

    NASA Astrophysics Data System (ADS)

    Luo, H.; Yang, G. L.; Furdyna, J. K.; Ram-Mohan, L. R.

    1991-10-01

    Magneto-optical transitions induced by the coupling between the conduction and the valence bands through the momentum matrix element, and by the coupling terms between light and heavy holes resulting from an applied magnetic field are studied theoretically in narrow gap HgTe-CdTe superlattices. Selection rules and transition probabilities for the above transitions are presented and compared with allowed transitions. The numerical results for the transition probabilities show that some of the interband transitions with ΔN=±1 are significant and have to be considered in the studies of interband magneto-optical spectra of narrow gap superlattices.

  15. Saffman-Taylor-like instability in a narrow gap induced by dielectric barrier discharge.

    PubMed

    Hou, Shang-Yan; Chu, Hong-Yu

    2015-07-01

    This work is inspired by the expansion of the plasma bubble in a narrow gap reported by Chu and Lee [Phys. Rev. Lett. 107, 225001 (2011)]. We report the unstable phenomena of the plasma-liquid interface with different curvature in a Hele-Shaw cell. Dielectric barrier discharge is produced in the cell at atmospheric pressure which is partially filled with silicone oil. We show that the Saffman-Taylor-like instability is observed on the bubble-type, channel-type, and drop-type interfaces. The Schlieren observation of the plasma-drop interaction reveals that there is a vapor layer around the drop and the particle image velocimetry shows the liquid flow inside the drop. We propose that the thermal Marangoni effect induced by the plasma heating is responsible for the unstable phenomena of the plasma-liquid interaction. The fluctuation of the interface is shown consistently with the Saffman-Taylor instability modified by the temperature-dependent velocity and surface tension. PMID:26274288

  16. Narrow Energy Gap between Triplet and Singlet Excited States of Sn2+ in Borate Glass

    PubMed Central

    Masai, Hirokazu; Yamada, Yasuhiro; Suzuki, Yuto; Teramura, Kentaro; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-01-01

    Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns2-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn2+-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors. PMID:24345869

  17. Narrow energy gap between triplet and singlet excited states of Sn2+ in borate glass.

    PubMed

    Masai, Hirokazu; Yamada, Yasuhiro; Suzuki, Yuto; Teramura, Kentaro; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-01-01

    Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns(2)-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn(2+)-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors. PMID:24345869

  18. Resonant Zener tunnelling via zero-dimensional states in a narrow gap diode

    PubMed Central

    Di Paola, D. M.; Kesaria, M.; Makarovsky, O.; Velichko, A.; Eaves, L.; Mori, N.; Krier, A.; Patanè, A.

    2016-01-01

    Interband tunnelling of carriers through a forbidden energy gap, known as Zener tunnelling, is a phenomenon of fundamental and technological interest. Its experimental observation in the Esaki p-n semiconductor diode has led to the first demonstration and exploitation of quantum tunnelling in a condensed matter system. Here we demonstrate a new type of Zener tunnelling that involves the resonant transmission of electrons through zero-dimensional (0D) states. In our devices, a narrow quantum well of the mid-infrared (MIR) alloy In(AsN) is placed in the intrinsic (i) layer of a p-i-n diode. The incorporation of nitrogen in the quantum well creates 0D states that are localized on nanometer lengthscales. These levels provide intermediate states that act as “stepping stones” for electrons tunnelling across the diode and give rise to a negative differential resistance (NDR) that is weakly dependent on temperature. These electron transport properties have potential for the development of nanometre-scale non-linear components for electronics and MIR photonics. PMID:27535896

  19. Resonant Zener tunnelling via zero-dimensional states in a narrow gap diode.

    PubMed

    Di Paola, D M; Kesaria, M; Makarovsky, O; Velichko, A; Eaves, L; Mori, N; Krier, A; Patanè, A

    2016-01-01

    Interband tunnelling of carriers through a forbidden energy gap, known as Zener tunnelling, is a phenomenon of fundamental and technological interest. Its experimental observation in the Esaki p-n semiconductor diode has led to the first demonstration and exploitation of quantum tunnelling in a condensed matter system. Here we demonstrate a new type of Zener tunnelling that involves the resonant transmission of electrons through zero-dimensional (0D) states. In our devices, a narrow quantum well of the mid-infrared (MIR) alloy In(AsN) is placed in the intrinsic (i) layer of a p-i-n diode. The incorporation of nitrogen in the quantum well creates 0D states that are localized on nanometer lengthscales. These levels provide intermediate states that act as "stepping stones" for electrons tunnelling across the diode and give rise to a negative differential resistance (NDR) that is weakly dependent on temperature. These electron transport properties have potential for the development of nanometre-scale non-linear components for electronics and MIR photonics. PMID:27535896

  20. Two Different Plasma Series Resonances in a 100MHz Driven Narrow Gap Capacitively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Choi, Myung-Sun; Lee, Seok-Hwan; Jang, Yunchang; Ryu, Sangwon; Jeong, Sangmin; Sung, Dougyong; Kim, Gon-Ho

    2014-10-01

    Plasma series resonance (PSR) is the resonance between the sheath displacement and the inductance of plasma bulk. Especially, the linear response of this resonance is called ``geometrical resonance'' which is distinguished with the non-linear response of that called ``self-excited PSR.'' In this work, geometrical series resonances of plasma slab in narrow gap (d = 0 . 02 m) between the RF electrode (r = 0 . 2 m) and floating electrode (r = 0 . 15 m) encircled with the earthed chamber (r = 0 . 3 m) were investigated with various applied 100 MHz powers from 100 W to 1 kW and operating pressures from 5 mTorr to 50 mTorr. The condition of plasma series resonance was monitored by using optical emission spectroscopy (OES) and amplitudes of current and voltage at the RF driven and counter electrodes. There were not only the plasma series resonance between the two parallel electrodes but also that between the RF driven electrode and the lateral wall of earthed chamber. Those two different plasma series resonances were observed alternatively with increasing applied power. In the session, the detailed analysis of alternatively arisen two different series resonances and influence of them on the discharge will be discussed. This work was partly supported by the Brain Korea 21 Plus Project (No. 21A20130012821).

  1. Stabilization of Novel Narrow Gap Semiconductor Phases Through Size Reduction to the Nanoscale

    NASA Astrophysics Data System (ADS)

    Soriano, Ronald B.

    The work on this dissertation is aimed at (1) preparations of multinary narrow gap semiconductor nanoparticles using hot-injection technique, (2) stabilization of novel narrow gap semiconductor nanocrystal phases, (3) elucidate the resulting structure and investigate their properties, and (4) understand the thermodynamic stability of the prepared nanomaterials. The first colloidal synthetic route for the synthesis of amorphous GeTe NPs using an amido-germanium precursor was reported. Interestingly, the amorphous particles prepared at low temperature conditions exhibit a well-defined local structure related to that of high-pressure orthorhombic GeTe. Furthermore, the amorphous GeTe NPs display nearly spherical morphology, narrow size dispersity and undergo amorphous-to-crystalline phase transition at slightly elevated temperatures compared to the bulk material. Nearly all activity in nanoparticle science to date has focused on preparing nanocrystals of almost any known bulk phase to investigate size-dependent properties. An unexplored frontier in this field is stabilizing materials with compositions and structures in the nanoscale that do not exist in the bulk, representing an unprecedented approach with the potential to introduce entirely new nanomaterials. The synthesis of single phase semiconductor Pb 2-xSnxS2 nanocrystals with cubic rock salt structure (Fm m) in a composition range that exists in the bulk as an orthorhombic structure (0.6 < x < 1) was demonstrated. New ternary nanocrystals of Pb-Sb-Te with cubic rock-salt type structure, which are mixtures of PbTe and Sb2Te3 in the bulk was successfully prepared. Pbm Sb2n Tem+3n nanocrystals are single phases and tend to phase separate at moderately high temperature. The new Pbm Sb2n Tem+3n nanocrystals define a new class of nanomaterials that only exist on the nanoscale but are unstable in the bulk. This approach of stabilizing novel phases is extended to both Pb-Sb-Se and Pb-Sb-S systems. Novel Pbm Sb2n Sem+3n

  2. Closing the Social Class Achievement Gap for First-Generation Students in Undergraduate Biology

    PubMed Central

    Harackiewicz, Judith M.; Canning, Elizabeth A.; Tibbetts, Yoi; Giffen, Cynthia J.; Blair, Seth S.; Rouse, Douglas I.; Hyde, Janet S.

    2014-01-01

    Many students start college intending to pursue a career in the biosciences, but too many abandon this goal because they struggle in introductory biology. Interventions have been developed to close achievement gaps for underrepresented minority students and women, but no prior research has attempted to close the gap for first-generation students, a population that accounts for nearly a fifth of college students. We report a values affirmation intervention conducted with 798 U.S. students (154 first-generation) in an introductory biology course for majors. For first-generation students, values affirmation significantly improved final course grades and retention in the second course in the biology sequence, as well as overall GPA for the semester. This brief intervention narrowed the achievement gap between first-generation and continuing generation students for course grades by 50% and increased retention in a critical gateway course by 20%. Our results suggest that educators can expand the pipeline for first-generation students to continue studying in the biosciences with psychological interventions. PMID:25049437

  3. Closing the Social Class Achievement Gap for First-Generation Students in Undergraduate Biology.

    PubMed

    Harackiewicz, Judith M; Canning, Elizabeth A; Tibbetts, Yoi; Giffen, Cynthia J; Blair, Seth S; Rouse, Douglas I; Hyde, Janet S

    2014-05-01

    Many students start college intending to pursue a career in the biosciences, but too many abandon this goal because they struggle in introductory biology. Interventions have been developed to close achievement gaps for underrepresented minority students and women, but no prior research has attempted to close the gap for first-generation students, a population that accounts for nearly a fifth of college students. We report a values affirmation intervention conducted with 798 U.S. students (154 first-generation) in an introductory biology course for majors. For first-generation students, values affirmation significantly improved final course grades and retention in the second course in the biology sequence, as well as overall GPA for the semester. This brief intervention narrowed the achievement gap between first-generation and continuing generation students for course grades by 50% and increased retention in a critical gateway course by 20%. Our results suggest that educators can expand the pipeline for first-generation students to continue studying in the biosciences with psychological interventions. PMID:25049437

  4. The strain induced band gap modulation from narrow gap semiconductor to half-metal on Ti{sub 2}CrGe: A first principles study

    SciTech Connect

    Li, Jia; Zhang, Zhidong; Lu, Zunming; Xie, Hongxian; Fang, Wei; Li, Shaomin; Liang, Chunyong; Yin, Fuxing

    2015-11-15

    The Heusler alloy Ti{sub 2}CrGe is a stable L2{sub 1} phase with antiferromagnetic ordering. With band-gap energy (∼ 0.18 eV) obtained from a first-principles calculation, it belongs to the group of narrow band gap semiconductor. The band-gap energy decreases with increasing lattice compression and disappears until a strain of −5%; moreover, gap contraction only occurs in the spin-down states, leading to half-metallic character at the −5% strain. The Ti{sub 1}, Ti{sub 2}, and Cr moments all exhibit linear changes in behavior within strains of −5%– +5%. Nevertheless, the total zero moment is robust for these strains. The imaginary part of the dielectric function for both up and down spin states shows a clear onset energy, indicating a corresponding electronic gap for the two spin channels.

  5. Kinetics of nickel electrodeposition from low electrolyte concentration and at a narrow interelectrode gap

    NASA Astrophysics Data System (ADS)

    Widayatno, Tri

    2015-12-01

    Electrodeposition of nickel onto copper in a system of low Ni2+ concentration and at a narrow interelectrode gap has been carried out. This electrochemical system was required for maskless pattern transfer through electroplating (Enface technique). Kinetics of Electrochemical reaction of Nickel is relatively slow, where such electrochemical system has never been used in this technology. Study on the kinetics of the electrochemical reaction of nickel in such system is essential due to the fact that the quality of an electrodeposited nickel is affected by kinetics. Analytical and graphical methods were utilised to determine kinetic parameters. The kinetic model was approximated by Butler-Volmer and j-η equation. Kinetic parameters such as exchange current density (j0) and charge transfer coefficient (α) were also graphically determined using the plot of η vs. log|j| known as Tafel plot. The polarisation data for an unstirred 0.19 M nickel sulfamate solution at 0.5 mV/s scan rate and RDE system was used. The results indicate that both methods are fairly accurate. For the analytical, the Tafel slope, the exchange current density, and charge transfer coefficient were found to be 149 mV/dec, 1.60 × 10-4 mA/cm2, and 0.39 respectively, whilst for the graphical method were 159 mV/dec, 3.16 × 10-4 mA/cm2, and 0.37. The kinetics parameters in this current study were also compared to those in literature. Significant differences were observed which might be due to the effect of composition and concentration of the electrolytes, operating temperature, and pH leading to the different reaction mechanism. However, the results obtained in this work are in the range of acceptable values. These kinetic parameters will then be used in further study of nickel deposition by modelling and simulation

  6. Extraordinary Magnetoresistance At Room Temperature In Non-Magnetic Narrow-Gap Semiconductor/Metal Composites

    NASA Astrophysics Data System (ADS)

    Solin, S. A.

    2001-03-01

    The magnetoresistance (MR) of a material object contains a physical contribution from the magnetic field dependence of the material parameters such as the mobility or carrier concentration and a geometric contribution from the dependence of the current path and output voltage on the sample shape and electrode configuration. To date, only two classes of magnetic materials, artificially layered metals which exhibit giant MR (GMR) and the manganite perovskites which exhibit colossal MR (CMR) have been considered serious candidates in the effort to improve the room temperature (RT) performance of MR sensors. For both of these classes, the physical MR dominates. In contrast, we have found that non-magnetic narrow-gap semiconductors containing patterned metallic inhomogeneities (shunts), exhibit RT geometric extraordinary MR (EMR) orders of magnitude larger than the physical MR of other materials. EMR in excess of 2000% at 0.05 Tesla and 3,000,000% at 5 T, respectively, has been observed in macroscopic ( ~ 1 mm) composite structures of InSb with patterned internal or external shunts.(S.A. Solin et al., Science 289), 1530 (2000).^,(T. Zhou, D.R. Hines and S.A. Solin, Appl. Phys. Lett., submitted.) We have been able to quantitatively account for the magnitude of the observed EMR as well as its dependence on the geometry (shape, size and placement of the shunt) using both analytic (Laplace equation with boundary conditions) and computational (Finite Element Analysis)(see the talk by L.R. Ram-Mohan et al., this conference) methods. The effect of scaling EMR structures to mesoscopic dimensions and the possible technological impact of EMR will be discussed.

  7. Pushing Past the Achievement Gap: An Essay on the Language of Deficit

    ERIC Educational Resources Information Center

    Ladson-Billings, Gloria

    2007-01-01

    Despite the intense focus on the achievement gap that exists between African American, Latino, and other students of color and their White counterparts, the achievement gap discourse keeps us locked in the deficit paradigm. This article challenges us to look at the inherent fallacies of the achievement gap discourse and place students' academic…

  8. Closing the Achievement Gap: Oregon's Plan for Success for All Students

    ERIC Educational Resources Information Center

    Oregon Department of Education, 2005

    2005-01-01

    Susan Castillo, Superintendent of Public Instruction in Oregon, named closing the achievement gap as a top instructional priority in Oregon. Superintendent Castillo notes three aspects to the achievement gap: (1) Performance gap: The discrepancies between the educational achievement and performance of students of diverse races, ethnicities, income…

  9. Patterns of Change in U.S. Gender Achievement Gaps during Elementary and Middle School

    ERIC Educational Resources Information Center

    Fahle, Erin

    2016-01-01

    Research on gender achievement gaps shows they exist, and are largest in the tails of the distribution, starting as early as Kindergarten and persisting through eighth grade. In mathematics, studies find small average gender achievement gaps and larger systematically male-favoring gaps among the highest achieving students. This paper seeks to…

  10. Narrowing the Gap in Outcomes for Vulnerable Groups: Overview and Analysis of Available Datasets on Vulnerable Groups and the Five ECM Outcomes. Executive Summary

    ERIC Educational Resources Information Center

    Morris, Marian

    2007-01-01

    This summary presents the main findings from a data mapping and analysis study commissioned by the Local Government Association (LGA) from the National Foundation for Educational Research (NFER) as part of a two-year development and research programme, Narrowing the Gap. This programme seeks to make a significant difference in "narrowing the gap"…

  11. Social-Emotional Factors Affecting Achievement Outcomes Among Disadvantaged Students: Closing the Achievement Gap.

    PubMed

    Becker, Bronwyn E; Luthar, Suniya S

    2002-01-01

    Despite concentrated efforts at improving inferior academic outcomes among disadvantaged students, a substantial achievement gap between the test scores of these students and others remains (Jencks & Phillips, 1998; National Center for Education Statistics, 2000a, 2000b; Valencia & Suzuki, 2000). Existing research used ecological models to document social-emotional factors at multiple levels of influence that undermine academic performance. This article integrates ideas from various perspectives in a comprehensive and interdisciplinary model that will inform policy makers, administrators, and schools about the social-emotional factors that act as both risk and protective factors for disadvantaged students' learning and opportunities for academic success. Four critical social-emotional components that influence achievement performance (academic and school attachment, teacher support, peer values, and mental health) are reviewed. PMID:23255834

  12. Social–Emotional Factors Affecting Achievement Outcomes Among Disadvantaged Students: Closing the Achievement Gap

    PubMed Central

    Becker, Bronwyn E.; Luthar, Suniya S.

    2012-01-01

    Despite concentrated efforts at improving inferior academic outcomes among disadvantaged students, a substantial achievement gap between the test scores of these students and others remains (Jencks & Phillips, 1998; National Center for Education Statistics, 2000a, 2000b; Valencia & Suzuki, 2000). Existing research used ecological models to document social–emotional factors at multiple levels of influence that undermine academic performance. This article integrates ideas from various perspectives in a comprehensive and interdisciplinary model that will inform policy makers, administrators, and schools about the social–emotional factors that act as both risk and protective factors for disadvantaged students’ learning and opportunities for academic success. Four critical social–emotional components that influence achievement performance (academic and school attachment, teacher support, peer values, and mental health) are reviewed. PMID:23255834

  13. Fabrication and characterization of low dimensional narrow energy gap semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Kang, Hyoung Ho

    In last decades, there has been a tremendous interest and a challenge to fabricate and characterize materials of nanoscale dimensions. Strong carrier confinement occurs in low dimensional systems showing different quantization regimes. These properties are being exploited for the fabrication of novel semiconductor devices. In this work, the fabrication and characterization of low dimensional narrow gap semiconductor heterostructures of 2-D InP/InAs quantum well/InP, 1-D Bi nanowires/mica and 0-D PbSe/PbEuTe quantum dot superlattice structures are presented. Stacking faults that are deleterious for the optical properties of heterostructures were observed in InP/InAs Q.W./InP (001) grown by ALE. A model for the formation of the stacking faults in InAs/InP heterostructures is proposed based on a transmission electron microscopy study. These faults were identified as Frank type faults and are believed to be responsible for the formation of tetrahedra or elongated hexahedra stacking faults. The density of stacking faults decreased as the InP cap layer thickness increased. Our investigation showed that the increase in stacking fault energy gives rise to annihilation of the faults as the cap layer thickness increases. Arrays of bismuth nanowires with diameter as small as 60 A on mica templates for the fabrication of thermoelectric devices were synthesized by a three-step process consisting of positive-ion irradiation, chemical etching and electrodeposition processes. The diameter and shape of the nanowires were controlled by the etching time. A single crystalline Bi wire with (012) in-plane orientation was observed by high resolution TEM and electron diffraction. The efficiency of electrodeposition of Bi wires was about 80%. N-doping of Bi wires by Te using electrodeposition was also demonstrated. The Te concentration was about 13 times higher than the concentration of Te in the solution. Ohmic behavior was observed across the doped Bi wires. The dot stacking arrangement

  14. Force and torque on a cylinder rotating in a narrow gap at low Reynolds number: Scaling and lubrication analyses

    NASA Astrophysics Data System (ADS)

    Yang, J.; Wolgemuth, C. W.; Huber, G.

    2013-05-01

    The hydrodynamic forces and torques on a rotating cylinder in a narrow channel are investigated in this paper using lubrication analysis and scaling analysis. To explore the effect of the shape of the gap, three different geometries are considered. The force and torque expressions from lubrication analysis agree well with numerical solutions when the gap between cylinder and wall is small. The solutions from scaling analysis can be applied over a broader range, but only if the scaling coefficients are properly deduced from numerical solution or lubrication analysis. Self-similarity in the solutions is discussed as well.

  15. State Test Score Trends through 2007-08, Part 3: Are Achievement Gaps Closing and Is Achievement Rising for All?

    ERIC Educational Resources Information Center

    Chudowsky, Naomi; Chudowsky, Victor; Kober, Nancy

    2009-01-01

    A main goal of the No Child Left Behind Act (NCLB) is to close gaps in test scores between different groups of students while raising achievement for all groups. Of particular concern are the persistent achievement gaps between African American, Latino, and Native American students and their white and Asian counterparts, and between students from…

  16. Black-White Achievement Gap and Family Wealth

    ERIC Educational Resources Information Center

    Yeung, W. Jean; Conley, Dalton

    2008-01-01

    This article examines the extent to which family wealth affects the Black-White test score gap for young children based on data from the Panel Study of Income Dynamics (aged 3-12). This study found little evidence that wealth mediated the Black-White test scores gaps, which were eliminated when child and family demographic covariates were held…

  17. Closing the Achievement Gap in Mathematics for Elementary School Students with Disabilities

    ERIC Educational Resources Information Center

    Bickford, Elizabeth K.

    2013-01-01

    An achievement gap exists in mathematics between elementary school students with and without disabilities. Guided by the conceptual framework of constructivism, this project study addressed issues related to this achievement gap in the area of mathematics, specifically assessing the cause of this gap from the teachers' perspective. The…

  18. Test Format and the Variation of Gender Achievement Gaps within the United States

    ERIC Educational Resources Information Center

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia

    2016-01-01

    Prior research demonstrates the existence of gender achievement gaps and the variation in the magnitude of these gaps across states. This paper characterizes the extent to which the variation of gender achievement gaps on standardized tests across the United States can be explained by differing state accountability test formats. A comprehensive…

  19. Is referencing the posterior condyles sufficient to achieve a rectangular flexion gap in total knee arthroplasty?

    PubMed

    Schnurr, Christoph; Nessler, Jochen; König, Dietmar Pierre

    2009-12-01

    Femoral malrotation in total knee arthroplasty causes flexion gap instability. Conventional instruments mostly reference the posterior condylar angle (PCA). The aim of this study was to verify whether the computer-navigated flexion gap (GAP) method produces a rectangular flexion gap and if a balanced flexion gap could also be achieved by referencing the PCA. A total of 100 knee prostheses were analysed using the navigated GAP method, and flexion gap symmetry along with femoral rotation were recorded. The GAP technique resulted in a rectangular flexion gap with adequate femoral rotational alignment. If the PCA technique had been used, only 51% of the femoral components would have been implanted in correct femoral rotation; the remaining 49% would have implanted with flexion gap instability. The GAP technique produces a rectangular flexion gap. The referencing of the PCA was shown to be less reliable. Thus, modern knee prosthesis instrumentation should not base femoral rotation solely on the PCA. PMID:18956189

  20. Removal of carbon films by oxidation in narrow gaps: Thermo-oxidation and plasma-assisted studies

    NASA Astrophysics Data System (ADS)

    Tanarro, I.; Ferreira, J. A.; Herrero, V. J.; Tabarés, F. L.; Gómez-Aleixandre, C.

    2009-06-01

    The removal of hard amorphous hydrogenated carbon (a-C:H) films from narrow gaps simulating the macro-brush structures present in controlled fusion devices has been investigated. Films with a thickness of 50-150 nm were generated through plasma-assisted chemical vapor deposition (PACVD) in glow discharges of CH 4/He on Si and stainless steel plates. The deposited plates were then arranged to form sandwich structures building narrow gaps and were subjected to erosion by exposure to O 2/He plasmas and to thermal oxidation by O 2 and by a NO 2/N 2 (1:1) mixture. In the plasma etching experiments, the deposited layers were only partially removed by the plasma at the side wall gap surfaces, but were efficiently removed at the bottom of the gap. In the thermo-oxidation experiments, the deposited films were effectively and homogeneously removed with oxygen at 670 K and with the NO 2/N 2 mixture at T > 570 K.

  1. First-principles study of direct and narrow band gap semiconducting β-CuGaO2

    NASA Astrophysics Data System (ADS)

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-04-01

    Semiconducting oxides have attracted much attention due to their great stability in air or water and the abundance of oxygen. Recent success in synthesizing a metastable phase of CuGaO2 with direct narrow band gap opens up new applications of semiconducting oxides as absorber layer for photovoltaics. Using first-principles density functional theory calculations, we investigate the thermodynamic and mechanical stabilities as well as the structural and electronic properties of the β-CuGaO2 phase. Our calculations show that the β-CuGaO2 structure is dynamically and mechanically stable. The energy band gap is confirmed to be direct at the Γ point of Brillouin zone. The optical absorption occurs right at the band gap edge and the density of states near the valance band maximum is large, inducing an intense absorption of light as observed in experiment.

  2. First-principles study of direct and narrow band gap semiconducting β -CuGaO2

    DOE PAGESBeta

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-04-16

    Semiconducting oxides have attracted much attention due to their great stability in air or water and the abundance of oxygen. Recent success in synthesizing a metastable phase of CuGaO2 with direct narrow band gap opens up new applications of semiconducting oxides as absorber layer for photovoltaics. Using first-principles density functional theory calculations, we investigate the thermodynamic and mechanical stabilities as well as the structural and electronic properties of the β-CuGaO2 phase. Our calculations show that the β-CuGaO2 structure is dynamically and mechanically stable. The energy band gap is confirmed to be direct at the Γ point of Brillouin zone. Inmore » conclusion, the optical absorption occurs right at the band gap edge and the density of states near the valance band maximum is large, inducing an intense absorption of light as observed in experiment.« less

  3. An organizational analysis of the World Health Organization: narrowing the gap between promise and performance.

    PubMed

    Peabody, J W

    1995-03-01

    The World Health Organization's (WHO's) nearly half century amelioration of suffering stands as a singular achievement in international cooperation. But after 45 years, the Organization has grown into a complex bureaucracy with an outdated organizational structure. A multidisciplinary framework, which emphasizes organizational theory, yields some insights into these problems. Using this approach, this paper examines the structure, culture, mission, and rules of WHO, and adds a perspective, not otherwise found in the literature, to the growing debate on the future of the Organization. Previous studies of international organizations have explained their behavior as the consequence of the dominant external interests of powerful members. This perspective suggests that organizations like WHO have fewer options and less control of their policies and output. By contrast, there has been very little analysis explaining how international organizations function internally. This paper refutes an exclusively external perspective and shows that the internal organization is also important to understanding WHO. Several conclusions are drawn from this perspective. WHO's organizational myths, as a politically neutral technical agency staffed with uniquely qualified staff, need to be validated and enhanced to attract funding. A new organizational structure, based on an 'open systems' model, is proposed. This strategy would strengthen the WHO Representative Country Offices, redefine staff objectives, close the Regional Offices, and establish open, public elections of the Director General. Traditional WHO culture should only be used for health problems that are well matched to WHO's critical tasks. For more complex social and economic issues, newer, often non-medical, approaches are needed. The internal and external rules, which shape the incentives of WHO staff and leaders, need to be realigned to close the gap between WHO's myths and its day to day work. In the short run it is

  4. Narrowing the gaps between what we know and what we do in psychiatry.

    PubMed

    Rush, A John

    2015-10-01

    There are many important research-practice gaps. Evidence to inform clinical decision-making is remarkably scant. A greater research focus on more clinically informative patient samples, clinically relevant questions, the use of innovative trial designs and analyses, and reporting of results in clinically understandable and potentially actionable ways can help reduce these gaps. Efforts to reduce intellectual silos, lessen the burden of research, and revise some academic incentives and publication practices would also be of help in reducing these gaps and hopefully improving patient care and outcomes. PMID:26528642

  5. Evaluating the Effects of Programs for Reducing Achievement Gaps: A Case Study in Taiwan

    ERIC Educational Resources Information Center

    Sung, Yao-Ting; Tseng, Fen-Lan; Kuo, Nien-Ping; Chang, Tien-Ying; Chiou, Jia-Min

    2014-01-01

    Considering that achievement gaps have become a serious educational problem worldwide, the Ministry of Education in Taiwan has been addressing a series of policies to reduce achievement gaps, but the effect of these policies has not yet been carefully examined. Therefore, the present study investigated current educational policies, achievement gap…

  6. Parsing the Achievement Gap: Baselines for Tracking Progress. Policy Information Report.

    ERIC Educational Resources Information Center

    Barton, Paul E.

    The gaps in school achievement among racial and ethnic groups and between students from poor and nonpoor families are well documented. They are large, and have been persistent. This publication is about conditions that help create and perpetuate achievement gaps. It focuses on the many antecedents of differences in school achievement college-going…

  7. What Factors Contribute to the Achievement Gap: A Case Study of Multicultural/Disadvantaged Student Participation in Co Curricular Activities at a Large Urban High School

    ERIC Educational Resources Information Center

    Jenkins, Carlton D.

    2009-01-01

    This quantitative research study used logistical regression and ordinary least squares to examine factors that contribute to the narrowing of the achievement gap at an urban high school in the Midwest. The study analyzed the relationship between five independent variables related to participation in co curricular activities, demographic…

  8. The Importance of Segregation, Discrimination, Peer Dynamics, and Identity in Explaining Trends in the Racial Achievement Gap. NBER Working Paper No. 16257

    ERIC Educational Resources Information Center

    Fryer, Roland G., Jr.

    2010-01-01

    After decades of narrowing, the achievement gap between black and white school children widened in the 1990s--a period when the labor market rewards for education were increasing. This presents an important puzzle for economists. In this chapter, I investigate the extent to which economic models of segregation, information-based discrimination,…

  9. Closing the Achievement Gap: Lessons Learned and Challenges Ahead.

    ERIC Educational Resources Information Center

    Green, R. Stephen

    2001-01-01

    Chronic disparities exist between the performance of minority and nonminority students on high-stakes standardized tests. Similar disparities exist on college admission. The College Board's Equity 2000 Project, implemented in 1990, gathered information on closing the gaps. Seven lessons learned from Equity 2000 emphasize the importance of such…

  10. Training School Counselors to Close the Achievement Gap

    ERIC Educational Resources Information Center

    Hartline, Julie B.

    2011-01-01

    The effectiveness of a training provided to school counselors on the implementation of comprehensive school counseling programs based on the ASCA National Model was examined. The data analyzed were the closing the gap summary results reports submitted following training. The reports were used to determine whether those trained could design,…

  11. 2-Year-College Leaders Discuss Achievement Gaps and Accountability

    ERIC Educational Resources Information Center

    Ashburn, Elyse

    2007-01-01

    This article describes the issues addressed at this year's American Association of Community Colleges' annual convention. The discussion centered on student success, including how colleges measure it, promote it, and are held accountable for it. One of the chief concerns expressed at the meeting was the gap between the retention, graduation, and…

  12. New Insights on the Burstein-Moss Shift and Band Gap Narrowing in Indium-Doped Zinc Oxide Thin Films.

    PubMed

    Saw, K G; Aznan, N M; Yam, F K; Ng, S S; Pung, S Y

    2015-01-01

    The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants. PMID:26517364

  13. New Insights on the Burstein-Moss Shift and Band Gap Narrowing in Indium-Doped Zinc Oxide Thin Films

    PubMed Central

    Saw, K. G.; Aznan, N. M.; Yam, F. K.; Ng, S. S.; Pung, S. Y.

    2015-01-01

    The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants. PMID:26517364

  14. Crystal growth and characterization of the narrow-band-gap semiconductors OsPn₂ (Pn = P, As, Sb).

    PubMed

    Bugaris, Daniel E; Malliakas, Christos D; Shoemaker, Daniel P; Do, Dat T; Chung, Duck Young; Mahanti, Subhendra D; Kanatzidis, Mercouri G

    2014-09-15

    Using metal fluxes, crystals of the binary osmium dipnictides OsPn2 (Pn = P, As, Sb) have been grown for the first time. Single-crystal X-ray diffraction confirms that these compounds crystallize in the marcasite structure type with orthorhombic space group Pnnm. The structure is a three-dimensional framework of corner- and edge-sharing OsPn6 octahedra, as well as [Pn2(4-)] anions. Raman spectroscopy shows the presence of P-P single bonds, consistent with the presence of [Pn2(-4)] anions and formally Os(4+) cations. Optical-band-gap and high-temperature electrical resistivity measurements indicate that these materials are narrow-band-gap semiconductors. The experimentally determined Seebeck coefficients reveal that nominally undoped OsP2 and OsSb2 are n-type semiconductors, whereas OsAs2 is p-type. Electronic band structure using density functional theory calculations shows that these compounds are indirect narrow-band-gap semiconductors. The bonding p orbitals associated with the Pn2 dimer are below the Fermi energy, and the corresponding antibonding states are above, consistent with a Pn-Pn single bond. Thermopower calculations using Boltzmann transport theory and constant relaxation time approximation show that these materials are potentially good thermoelectrics, in agreement with experiment. PMID:25162930

  15. Eliminating the Achievement Gap: A White Paper on How Charter Schools Can Help District Leaders

    ERIC Educational Resources Information Center

    Lake, Robin; Hernandez, Alex

    2011-01-01

    A staggering achievement gap exists between minority and white students in America. The gap is unjust, and it is constraining the country economically, socially, and politically. Intense political pressures, labor contracts, and other forces prevent urban superintendents from closing those gaps. However, partnerships with high-performing charter…

  16. The Economic Impact of Achievement Gaps in Pennsylvania's Public Schools. Research Report

    ERIC Educational Resources Information Center

    Karoly, Lynn A.

    2015-01-01

    This study documents the magnitude of the gaps in student performance for public school students in Pennsylvania and estimates the economic consequences of those education performance gaps. Although Pennsylvania is one of the top-scoring states on the 2013 National Assessment of Educational Progress (NAEP) on average, the achievement gaps between…

  17. Measuring Cognitive Achievement Gaps and Inequalities: The Case of Brazil

    ERIC Educational Resources Information Center

    Soares, Jose Francisco

    2006-01-01

    This paper introduces a new measure of educational inequalities based on cognitive achievement data, and uses it to examine achievement inequalities in mathematics between groups of students enrolled in basic education in Brazil. The groups of students are defined by their race, sex, socioeconomic status (SES), and region of residence. The…

  18. Subgroup Achievement and Gap Trends: District of Columbia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    The District's demographics are such that achievement trends could only be determined for African American, male and female, and low income subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Washington, DC students showed gains in both reading and math at the basic, proficient, and advanced levels…

  19. Narrowing the College Opportunity Gap: Helping Students and Families Navigate the Financial Aid Process

    ERIC Educational Resources Information Center

    Owen, Laura

    2012-01-01

    The number of students enrolling in post-secondary institutions in the U.S. has slowly been rising over the last 10 years, yet gaps continue to exist in terms of who attends college and persists through graduation. Minority and low income students often lack the guidance needed to navigate the college enrollment process and as a result, remain…

  20. Interband and intraband contributions to refractive index and dispersion in narrow-gap semiconductors

    NASA Astrophysics Data System (ADS)

    Herrmann, K. H.; Melzer, V.; Müller, U.

    1993-04-01

    This review covers experimental methods and results for the determination of refractive index. It discusses various empirical relations between refractive index and energy gap (Moss relation, Ravindra and Gopal formulae and the Wemple DiDomenico approach). Effects of free carriers and temperature are included. Finally, the Kramers-Kronig transformation of absorption or reflection spectra is considered.

  1. Addressing Achievement Gaps: School Finance and the Achievement Gap--Funding Programs That Work. Policy Notes. Volume 16, Number 3, Fall 2008

    ERIC Educational Resources Information Center

    Yaffe, Deborah

    2008-01-01

    In education reform, money matters, but so does spending it wisely--on programs designed to meet the ambitious goal of helping low-income and minority children achieve at the same levels as their more affluent peers. The latest in the Educational Testing Service's (ETS's) series of symposia on Addressing Achievement Gaps brought researchers,…

  2. Moving to higher ground: Closing the high school science achievement gap

    NASA Astrophysics Data System (ADS)

    Mebane, Joyce Graham

    be implemented at West High School: (1) Have high expectations for all students. (2) Encourage students to take advanced science courses and help them succeed in these advanced science courses. (3) Improve communications among students, parents, teachers, administrators, and guidance counselors regarding procedures, policies, programs, and goals at the school. (4) Assign guidance counselors per grade level rather than across grade levels. (5) Have procedures in place so information from guidance counselors is consistent. (6) Increase parental involvement in the school. Simply increasing the number of and variety of AP science and IB science courses will not result in closing the achievement gap. All constituents must be positive about both preparation and interest of African American students in completing advanced science courses if these courses are indeed to narrow the achievement gap.

  3. Teachers, Technology and Training: A New Year's Resolution for 2006: Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Donlevy, Jim

    2006-01-01

    Recognizing the glaring discrepancies in outcomes for many poor and minority children, the New York State Regents hosted an Education Summit in November 2005 with the theme of Closing the Achievement Gap. Leaders in business, government and education were in attendance and rallied to more thoroughly understand the achievement gap and produce…

  4. Educating the African American Male College Student: The Achievement Gap Factor

    ERIC Educational Resources Information Center

    Moyo, Tawonga Timothy

    2013-01-01

    The academic achievement gap persists in spite of much concern and talk in both the educational and political arenas. Moreover, literature on the education of African American male students at the college level is scarce; the existing literature is on the achievement gap issue in general. In this phenomenological study, the academic achievement…

  5. One of Us Cannot Be Wrong: The Paradox of Achievement Gaps.

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2000-01-01

    Focuses on two general groups of methods that can be used to calculate achievement gaps between groups of students. States that the methods produce radically different results. Considers both of these methods and related problems in the calculation of achievement gaps in solving the contradiction between the two methods. Includes references. (CMK)

  6. Technology Enhanced Learning Environments for Closing the Gap in Student Achievement between Regions: Does It Work?

    ERIC Educational Resources Information Center

    Cakir, Hasan; Delialioglu, Omer; Dennis, Alan; Duffy, Thomas

    2009-01-01

    Student achievement gap between urban and suburban regions are a major issue in U.S. schools. Technology enhanced learning environments that support teaching and learning process with advanced technology may close this achievement gap. This paper examines the impact of student and school factors with an emphasis on schools' geographic location on…

  7. Connecting Social Disorganization Theory to African-American Outcomes to Explain the Achievement Gap

    ERIC Educational Resources Information Center

    Madyun, Na'im H.

    2011-01-01

    African-American student achievement outcomes have been and continue to be a critical concern for education researchers. Much of the framing of African-American student outcomes centers on what is known as achievement gaps that exist between African-American and White students. Unfortunately, these gaps have remained roughly the same since the…

  8. School Administrators' Perceptions of the Achievement Gap between African American Students and White Students

    ERIC Educational Resources Information Center

    Royle, Jonathan; Brown, Casey Graham

    2014-01-01

    This study included an analysis of principal perceptions of the achievement gap between African American and White students. School administrators from campuses with a substantial number of African American students within the subgroup were interviewed to explore their perceptions of the achievement gap. The study revealed factors within the…

  9. The Black-White Achievement Gap through the Lens of Central Office Administrators

    ERIC Educational Resources Information Center

    Baskin, Roger S., Sr.

    2013-01-01

    This study investigated the perceptions of Black and White central office administrators regarding the Black-White achievement gap. Four research questions (RQ) were explored: RQ1: How do central office administrators understand the causes of the Black-White achievement gap? RQ2: How do central office administrators perceive their role in…

  10. A Meta-Analysis on the Factors That Best Reduce the Achievement Gap

    ERIC Educational Resources Information Center

    Jeynes, William H.

    2015-01-01

    A meta-analyses was undertaken to determine the factors that are most related with reducing the achievement gap. The meta-analysis included 30 studies that examined attempts to bridge the achievement gap between White students on one hand and Black and Latino students on the other. The results indicate that several factors are associated with a…

  11. Are Boys Left Behind? The Evolution of the Gender Achievement Gap in Beijing's Middle Schools

    ERIC Educational Resources Information Center

    Lai, Fang

    2010-01-01

    Using one cohort of 7235 middle school students in Beijing, China, we examined the evolution of the gender achievement gap in middle school. Our study found a more significant female dominance than in U.S. studies: even though boys gradually caught up during middle school, especially in Math and Science, and the gender achievement gap decreased…

  12. The New Literacies of Online Research and Comprehension: Rethinking the Reading Achievement Gap

    ERIC Educational Resources Information Center

    Leu, Donald J.; Forzani, Elena; Rhoads, Chris; Maykel, Cheryl; Kennedy, Clint; Timbrell, Nicole

    2015-01-01

    Is there an achievement gap for online reading ability based on income inequality that is separate from the achievement gap in traditional, offline reading? This possibility was examined between students in two pseudonymous school districts: West Town (economically advantaged) and East Town (economically challenged; N = 256). Performance-based…

  13. School Composition and the Black-White Achievement Gap. NCES 2015-018

    ERIC Educational Resources Information Center

    Bohrnstedt, G.; Kitmitto, S.; Ogut, B.; Sherman, D.; Chan, D.

    2015-01-01

    School Composition and the Black-White Achievement Gap explores public schools' demographic composition, in particular, the proportion of Black students enrolled in schools (also referred to "Black student density" in schools) and its relation to the Black-White achievement gap. This NCES study, the first of its kind, used the 2011 NAEP…

  14. Cross Sectional and Longitudinal Portrayals of the Special Education Mathematics Achievement Gap. Research Brief 10

    ERIC Educational Resources Information Center

    Schulte, Ann C.; Stevens, Joseph J.

    2014-01-01

    We contrasted portrayals of the achievement gap on the North Carolina state mathematics assessment for students with disabilities (SWD) using two different ways of identifying this group of students. The first method used students' disability status in third grade as the basis for identifying SWD, and then tracked the achievement gap between SWD…

  15. The Relationship between the Minority Student Achievement Gap and Collective Teacher Efficacy

    ERIC Educational Resources Information Center

    O'Hara, Jane A.

    2011-01-01

    The purpose of this study was to determine the relationship between Collective Teacher Efficacy and minority student achievement gap over and above that explained by socioeconomics, school size, and prior achievement gaps for Black and Hispanic students with White students. Forty-seven Virginia middle schools were selected to participate in the…

  16. Once, Sometimes, or Always in Special Education: Mathematics Growth and Achievement Gaps

    ERIC Educational Resources Information Center

    Schulte, Ann C.; Stevens, Joseph J.

    2015-01-01

    This study used a statewide longitudinal sample to examine mathematics achievement gaps and growth in students with and without disabilities and to examine the impact of different methods of determining disability group membership on achievement gaps and growth. When disability status was determined on the basis of special education placement each…

  17. Magnetism switching and band-gap narrowing in Ni-doped PbTiO{sub 3} thin films

    SciTech Connect

    Zhou, Wenliang; Yu, Lu; Yang, Pingxiong Chu, Junhao; Deng, Hongmei

    2015-05-21

    Ions doping-driven structural phase transition accompanied by magnetism switching and band-gap narrowing effects has been observed in PbTi{sub 1−x}Ni{sub x}O{sub 3−δ} (xPTNO, x = 0.00, 0.06, and 0.33) thin films. With the increase of x, the xPTNO thin films exhibit not only a phase transition from the pseudotetragonal structure to a centrosymmetric cubic structure but also a drastic decrease of grain size. Moreover, the as-grown Ni-doped PbTiO{sub 3} (PTO) thin films show obvious room-temperature ferromagnetism and an increased saturation magnetization with increasing the Ni content, in contrast to undoped PTO, which shows diamagnetism. A bound magnetic polaron model was proposed to understand the observed ferromagnetic behavior of PTO-derived perovskite thin films. Furthermore, the 0.33PTNO thin film presents a narrowed band-gap, much smaller than that of PTO, which is attributed to new states of both the highest occupied molecular orbital and the lowest unoccupied molecular orbital in an electronic structure with the presence of Ni. These findings may open up a route to explore promising perovskite oxides as candidate materials for use in multiferroics and solar-energy devices.

  18. Broad and Narrow Personality Traits Predicting Academic Achievement over Compulsory Schooling: A Cross-Sectional Study in Two Countries

    ERIC Educational Resources Information Center

    Zupancic, Maja; Kavcic, Tina; Slobodskaya, Helena R.; Akhmetova, Olga A.

    2016-01-01

    Incremental predictive value of 5 broad and 13 narrow personality traits for academic achievement over and beyond age, gender, parental education, and country was examined in Russian and Slovene 8- to 15-year-olds. Personality data were collected from mothers (Russia: N = 994, Slovenia: N = 624) and adolescents (Russia: N = 481, Slovenia: N = 310)…

  19. Achievement Gaps and Correlates of Early Mathematics Achievement: Evidence from the ECLS K-First Grade Sample

    ERIC Educational Resources Information Center

    Chatterji, Madhabi

    2005-01-01

    In light of the NCLB Act of 2001, this study estimated mathematics achievement gaps in different subgroups of kindergartners and first graders, and identified child- and school-level correlates and moderators of early mathematics achievement. A subset of 2300 students nested in 182 schools from the Early Childhood Longitudinal Study K-First Grade…

  20. Is the Black-White Achievement Gap a Public Sector Effect? An Examination of Student Achievement in the Third Grade

    ERIC Educational Resources Information Center

    Simms, Kathryn

    2012-01-01

    Prior research has suggested private school education in middle school and high school as a solution for the Black-White achievement gap. However, more recent research calls this solution into question. Additionally, research increasingly implicates third grade as being of preeminent importance in driving students' subsequent academic achievement.…

  1. Academically Resilient Latino Elementary Students Bridging the Achievement Gap

    ERIC Educational Resources Information Center

    Diamond, Elena; Furlong, Michael J.; Quirk, Matthew

    2016-01-01

    This study investigated associations between school-readiness patterns of Latino students and their subsequent academic achievement. After identifying a subgroup of students with academic risk at kindergarten entry who showed signs of later average or better academic skill development, academic data were gathered to explore how this group of…

  2. Understanding the Gap in Mathematics Achievement of Malaysian Students

    ERIC Educational Resources Information Center

    Ismail, Noor Azina

    2009-01-01

    Of 46 countries that participated in the Trends in International Mathematics and Science Study in 2003 (I. V. S. Mullis, M. O. Martin, E. J. Gonzalez, & S. J. Chrostowski, 2004), Malaysia was ranked 10th in international scores of mathematics achievement for 8th-grade students. The present author aimed to examine the importance of students' home…

  3. Asthma and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of asthma among school-aged urban minority youth, causal pathways through which poorly controlled asthma adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Methods: Literature review. Results: Asthma is the most common chronic…

  4. Closing the Achievement Gap: A Structured Approach to Group Counseling

    ERIC Educational Resources Information Center

    Campbell, Chari A.; Brigman, Greg

    2005-01-01

    This study evaluated the impact of a group counseling intervention on student academic and social performance. Twenty-five school counselors were trained to use a structured approach to small-group counseling with students scoring in the mid-to-low range in math and reading. The group intervention focused on improving student achievement and…

  5. Breakfast and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of breakfast consumption among school-aged urban minority youth, causal pathways through which skipping breakfast adversely affects academic achievement, and proven or promising approaches for schools to increase breakfast consumption. Methods: Literature review. Results: On any given day a…

  6. Teen Pregnancy and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of teen pregnancy among school-aged urban minority youth, causal pathways through which nonmarital teen births adversely affects academic achievement, and proven or promising approaches for schools to address this problem. Methods: Literature review. Results: In 2006, the birth rate among 15-…

  7. Achievement Gap. Early Developments. Volume 11, Number 2, Fall 2007

    ERIC Educational Resources Information Center

    Winton, Pam, Ed.; Buysse, Virginia, Ed.; Zimmerman, Tracy, Ed.

    2007-01-01

    Research has identified a host of factors that likely contribute to the disparity in achievement, negating the possibility that a one-size-fits-all answer exists. Therefore, the initiatives highlighted in this issue of "Early Developments" address a variety of approaches. This issue of "Early Developments" includes the following articles: (1) The…

  8. Physical Activity and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of physical activity among school-aged urban minority youth, causal pathways through which low levels of physical activity and fitness adversely affects academic achievement, and proven or promising approaches for schools to increase physical activity and physical fitness among youth. Methods:…

  9. Vision and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of vision problems among school-aged urban minority youth, causal pathways through which vision problems adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Methods: Literature review. Results: More than 20% of school-aged youth have…

  10. Does High Quality Childcare Narrow the Achievement Gap at Two Years of Age?

    ERIC Educational Resources Information Center

    Ruzek, Erik; Burchinal, Margaret; Farkas, George; Duncan, Greg; Dang, Tran; Lee, Weilin

    2011-01-01

    The authors use the ECLS-B, a nationally-representative study of children born in 2001 to report the child care arrangements and quality characteristics for 2-year olds in the United States and to estimate the effects of differing levels of child care quality on two-year old children's cognitive development. Their goal is to test whether high…

  11. How Family Background Influences Student Achievement: Can Schools Narrow the Gap?

    ERIC Educational Resources Information Center

    Egalite, Anna J.

    2016-01-01

    On the weekend before the Fourth of July 1966, the U.S. Office of Education quietly released a 737-page report that summarized one of the most comprehensive studies of American education ever conducted. Encompassing some 3,000 schools, nearly 600,000 students, and thousands of teachers, and produced by a team led by Johns Hopkins University…

  12. Time resolved photoluminescence spectroscopy of narrow gap Hg1-xCdxTe/CdyHg1-yTe quantum well heterostructures

    NASA Astrophysics Data System (ADS)

    Morozov, S. V.; Rumyantsev, V. V.; Antonov, A. V.; Kadykov, A. M.; Maremyanin, K. V.; Kudryavtsev, K. E.; Mikhailov, N. N.; Dvoretskii, S. A.; Gavrilenko, V. I.

    2014-07-01

    Photoluminescence (PL) spectra and kinetics of narrow gap Hg1-xCdxTe/CdyHg1-yTe quantum well (QW) heterostructures grown by molecular beam epitaxy technique are studied. Interband PL spectra are observed from 18 K up to the room temperature. Time resolved studies reveal an additional PL line with slow kinetics (7 μs at 18 K) related to deep defect states in barrier layers. These states act as traps counteracting carrier injection into QWs. The decay time of PL signal from QW layers is about 5 μs showing that gain can be achieved at wavelengths 10-20 μm by placing such QWs in HgCdTe structures with waveguides.

  13. Improvement of program to calculate electronic properties of narrow band gap materials

    NASA Technical Reports Server (NTRS)

    Patterson, James D.; Abdelhakiem, Wafaa

    1991-01-01

    The program was improved by reprogramming it so it will run on both a SUN and a VAX. Also it is easily transportable as it is on a disk for use on a SUN. A computer literature search resulted in some improved parameters for Hg(1-x)Cd(x)Te and a table of parameters for Hg(1-x)Zn(x)Te. The effects of neutral defects were added to the program, and it was found, as expected, that they contribute very little to the mobility at temperatures of interest. The effect were added of varying the following parameters: dielectric constants, screening parameters, disorder energies, donor and acceptor concentrations, momentum matrix element, different expressions for energy gap, and transverse effective charge.

  14. Strategies to improve health coverage and narrow the equity gap in child survival, health, and nutrition.

    PubMed

    Chopra, Mickey; Sharkey, Alyssa; Dalmiya, Nita; Anthony, David; Binkin, Nancy

    2012-10-13

    Implementation of innovative strategies to improve coverage of evidence-based interventions, especially in the most marginalised populations, is a key focus of policy makers and planners aiming to improve child survival, health, and nutrition. We present a three-step approach to improvement of the effective coverage of essential interventions. First, we identify four different intervention delivery channels--ie, clinical or curative, outreach, community-based preventive or promotional, and legislative or mass media. Second, we classify which interventions' deliveries can be improved or changed within their channel or by switching to another channel. Finally, we do a meta-review of both published and unpublished reviews to examine the evidence for a range of strategies designed to overcome supply and demand bottlenecks to effective coverage of interventions that improve child survival, health, and nutrition. Although knowledge gaps exist, several strategies show promise for improving coverage of effective interventions-and, in some cases, health outcomes in children-including expanded roles for lay health workers, task shifting, reduction of financial barriers, increases in human-resource availability and geographical access, and use of the private sector. Policy makers and planners should be informed of this evidence as they choose strategies in which to invest their scarce resources. PMID:22999430

  15. General formulation for the calibration and characterization of narrow-gap etalons: the OSIRIS/GTC tunable filters case

    NASA Astrophysics Data System (ADS)

    González, J. J.; Cepa, J.; González-Serrano, J. I.; Sánchez-Portal, M.

    2014-10-01

    Tunable filters (TFs) are a powerful way of implementing narrow-band imaging mode over wide wavelength ranges, without the need of purchasing a large number of narrow-band filters covering all strong emission or absorption lines at any redshift. However, one of its main features is a wavelength variation across the field of view, sometimes termed the phase effect. In this work, an anomalous phase effect is reported and characterized for the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) instrument at the 10.4 m Gran Telescopio Canarias. The transmitted wavelength across the field of view of the instrument depends, not only on the distance to the optical centre, but on wavelength. This effect is calibrated for the red TF of OSIRIS by measuring both normal-incidence light at laboratory and spectral lamps at the telescope at non-normal incidence. This effect can be explained by taking into account the inner coatings of the etalon. In a high spectral resolution etalon, the gap between plates is much larger than the thickness of the inner reflective coatings. In the case of a TF, like that in OSIRIS, the coatings thickness could be of the order of the cavity, which changes drastically the effective gap of the etalon. We show that by including thick and dispersive coatings into the interference equations, the observed anomalous phase effect can be perfectly reproduced. In fact, we find that, for the OSIRIS red TF, a two-coatings model fits the data with an rms of 0.5 Å at all wavelengths and incidence angles. This is a general physical model that can be applied to other TF instruments.

  16. Building a Bridge to Span the Minority-Majority Achievement Gap.

    ERIC Educational Resources Information Center

    Lanasa, Philip J., III; Potter, Jane Hopkins

    A number of hypotheses have been advanced to explain why black students lag behind whites in school achievement. In the 1950s and 1960s, an environmental hypothesis emerged which attributed the achievement gap to environment. Environmentalists at this point were divided between those who felt the family determined achievement and those who felt…

  17. Another Look at the Achievement Gap: Learning from the Experiences of Gifted Black Students

    ERIC Educational Resources Information Center

    Ford, Donna Y.; Grantham, Tarek C.; Whiting, Gilman W.

    2008-01-01

    Many studies have been conducted on the achievement gap, with most findings pointing to how school and family variables affect Black students' achievement. Another body of work focuses on how social variables (i.e., peers) impact Black students' achievement, including how accusations of "acting White" affect the performance of Black students and…

  18. Creating the Opportunity to Learn: Moving from Research to Practice to Close the Achievement Gap

    ERIC Educational Resources Information Center

    Boykin, Wade; Noguera, Pedro

    2011-01-01

    After years of applying more pressure on schools to raise achievement levels for all students, particularly those who underperform their mainstream peers, the achievement gap today remains virtually unchanged. But the reality is that there's proof that, under the right conditions, all students can achieve at high levels. Instead of "quick-fix…

  19. Two phase flow of liquids in a narrow gap: Phase interference and hysteresis

    NASA Astrophysics Data System (ADS)

    Raza, Salim; Hejazi, S. Hossein; Gates, Ian D.

    2016-07-01

    Co-current flow of two immiscible liquids, such as oil and water in a planar fracture, exhibits nonlinear structures which become important in many natural and engineering systems such as subsurface flows, multiphase flows in lubrication joints, and coating flows. In this context, co-current flow of oil and water with variable rates is experimentally studied in a Hele-Shaw cell, various flow regimes are classified, and relative permeabilities for the phases are analysed thoroughly. Similar to multiphase pipe flows, multiphase flow in planar gaps shows various flow regimes, each having different flow rate/pressure gradient behaviour. As well as recovering the known results in the immiscible displacements in Hele-Shaw cell where the fluid-fluid interface remains stable/unstable for favorable/adverse viscosity ratios, it is found that the co-current flow of two fluids with different viscosities results in three distinct flow regimes. Before breakthrough of non-wetting phase, i.e, water, a "linear displacement" flow regime initially establishes at very low water injection rates. This stable movement turns into a "fingering advancement" flow regime at high water flow rates and Saffman-Taylor instability develops normal to the direction of the flow. After the breakthrough, a "droplet formation" flow regime is identified where the droplets of wetting phase, oil, are trapped in the water phase. For subsurface flow applications, we quantify these regimes through relative permeability curves. It is reported that as the water flow rate increases, the relative permeabilities and flow channels become smooth and regular. This behaviour of relative permeability and saturations shows dominance of capillary forces at low flow rates and viscous forces at higher flow rates. Variable injection rates provide the interface structures for both drainage and imbibition process, where the wetting phase saturation decreases and increases respectively. It is shown that relative permeability

  20. School Effects and Ethnic, Gender and Socio-Economic Gaps in Educational Achievement at Age 11

    ERIC Educational Resources Information Center

    Strand, Steve

    2014-01-01

    There are long-standing achievement gaps in England associated with socio-economic status (SES), ethnicity and gender, but relatively little research has evaluated interactions between these variables or explored school effects on such gaps. This paper analyses the national test results at age 7 and age 11 of 2,836 pupils attending 68 mainstream…

  1. Exploring Family, Neighborhood and School Factors in Racial Achievement Gap Dissertation

    ERIC Educational Resources Information Center

    Montoya, Silvia

    2010-01-01

    The racial achievement gap has been at the center of the educational debate for decades in the United States. Although disparities in educational outcomes have declined in part of the 20th century, the process has stalled in this decade. For instance, in mathematics the gap in raw scores for students aged 13 has decline from 41 points in 1978 to…

  2. Reassessing the Achievement Gap: Fully Measuring What Students Should Be Taught in School

    ERIC Educational Resources Information Center

    Rothstein, Richard; Jacobsen, Rebecca; Wilder, Tamara

    2008-01-01

    This presentation summarizes two products of the ongoing work the authors are doing for the Campaign for Educational Equity. Part 1 of this presentation is a summary of "A Report Card on Comprehensive Equity: Racial Gaps in the Nation's Youth Outcomes." This report estimates the black-white achievement gaps in each of these aspects of education…

  3. Online Penalty: The Impact of Online Instruction on the Latino-White Achievement Gap

    ERIC Educational Resources Information Center

    Kaupp, Ray

    2012-01-01

    Despite a substantial body of research on the effectiveness of distance education at the post-secondary level, little is known about the impact of online course delivery on the achievement gap. In California, the gap between white and Latino post-secondary student outcomes is significant and persistent, with Latino students overrepresented in…

  4. Closing the Achievement Gap with Culturally Relevant Technology-Based Learning Environments

    ERIC Educational Resources Information Center

    Joseph, Roberto

    2009-01-01

    The most significant educational problem of our time has been the achievement gap. The author discusses the need for the field of educational technology to join in the social movement to close this gap. He provides background on the significance of incorporating culture throughout the design and development of technology-based learning…

  5. The Achievement Gap in U.S. Education: Canaries in the Mine

    ERIC Educational Resources Information Center

    Singham, Mano

    2005-01-01

    There has been very little progress in closing the Black/White achievement gap in education. In this book, the author Mano Singham takes a look at this problem in the context of larger political realities and contends that in order to understand this gap, we must determine what is happening within the educational system as a whole. This book…

  6. School and Individual Factors That Contribute to the Achievement Gap in College Admissions Tests in Chile

    ERIC Educational Resources Information Center

    Perez Mejias, Paulina

    2012-01-01

    In Chile, reports and research papers have shown that there is an achievement gap in college admissions tests mostly associated to students' gender, socioeconomic status and type of school attended. This gap represents a barrier for low-income and female students to access higher education, as well as for graduates of public schools. Prior…

  7. Geographic Variation of District-Level Gender Achievement Gaps within the United States

    ERIC Educational Resources Information Center

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia

    2016-01-01

    Gender achievement gaps on national and state assessments have been a popular research topic over the last few decades. Many prior studies examine these gaps in different subjects (e.g., mathematics, reading, and science) and grades (typically kindergarten through eighth grade) for students living in various regions (typically states or countries)…

  8. Closing the Social Class Achievement Gap for First-Generation Students in Undergraduate Biology

    ERIC Educational Resources Information Center

    Harackiewicz, Judith M.; Canning, Elizabeth A.; Tibbetts, Yoi; Giffen, Cynthia J.; Blair, Seth S.; Rouse, Douglas I.; Hyde, Janet S.

    2014-01-01

    Many students start college intending to pursue a career in the biosciences, but too many abandon this goal because they struggle in introductory biology. Interventions have been developed to close achievement gaps for underrepresented minority students and women, but no prior research has attempted to close the gap for first-generation students,…

  9. International Evidence on Ability Grouping with Curriculum Differentiation and the Achievement Gap in Secondary Schools

    ERIC Educational Resources Information Center

    Schofield, Janet Ward

    2010-01-01

    Background/Context: The achievement gap between students from different backgrounds is an issue of grave concern in the United States and in many other developed countries. U.S. research suggests that tracking and other forms of ability grouping with curriculum differentiation may be implicated in increasing this gap. Unfortunately, U.S.…

  10. Surface leakage reduction in narrow band gap type-II antimonide-based superlattice photodiodes

    SciTech Connect

    Huang, Edward Kwei-wei; Hoffman, Darin; Nguyen, Binh-Minh; Delaunay, Pierre-Yves; Razeghi, Manijeh

    2009-02-02

    Inductively coupled plasma (ICP) dry etching rendered structural and electrical enhancements on type-II antimonide-based superlattices compared to those delineated by electron cyclotron resonance (ECR) with a regenerative chemical wet etch. The surface resistivity of 4x10{sup 5} {omega} cm is evidence of the surface quality achieved with ICP etching and polyimide passivation. By only modifying the etching technique in the fabrication steps, the ICP-etched devices with a 9.3 {mu}m cutoff wavelength revealed a diffusion-limited dark current density of 4.1x10{sup -6} A/cm{sup 2} and a maximum differential resistance at zero bias in excess of 5300 {omega} cm{sup 2} at 77 K, which are an order of magnitude better in comparison to the ECR-etched devices.

  11. Narrowing the gap in understanding protein structure and function through computer simulations

    NASA Astrophysics Data System (ADS)

    Guo, Hong

    2012-06-01

    Quantum mechanical/molecular mechanical (QM/MM) free energy simulations are applied for understanding mechanisms of different enzyme-catalyzed reactions and for determining some of the key factors in transition state (TS) stabilization and substrate specificity, two of the most important properties of enzymes. It is demonstrated here based on the results of computer simulations on kumamolisin-As, a member of sedolisin family, and DIM-5 and SET7/9, two of protein lysine methyltransferases, that transition state stabilization may be achieved in part through the general acid/base mechanism or the binding of the substrate in the TS-like configuration. Moreover, it is shown that dynamic substrate assisted catalysis may play an important role in the substrate specificity of enzymes.

  12. The role of school performance in narrowing gender gaps in the formation of STEM aspirations: a cross-national study.

    PubMed

    Mann, Allison; Legewie, Joscha; DiPrete, Thomas A

    2015-01-01

    This study uses cross-national evidence to estimate the effect of school peer performance on the size of the gender gap in the formation of STEM career aspirations. We argue that STEM aspirations are influenced not only by gender stereotyping in the national culture but also by the performance of peers in the local school environment. Our analyses are based on the Program for International Student Assessment (PISA). They investigate whether 15-year-old students from 55 different countries expect to have STEM jobs at the age of 30. We find considerable gender differences in the plans to pursue careers in STEM occupations in all countries. Using PISA test scores in math and science aggregated at the school level as a measure of school performance, we find that stronger performance environments have a negative impact on student career aspirations in STEM. Although girls are less likely than boys to aspire to STEM occupations, even when they have comparable abilities, boys respond more than girls to competitive school performance environments. As a consequence, the aspirations gender gap narrows for high-performing students in stronger performance environments. We show that those effects are larger in countries that do not sort students into different educational tracks. PMID:25762961

  13. Trap State Introduction versus Band Gap Narrowing in Nitrogen-Doped La2Ti2O7

    NASA Astrophysics Data System (ADS)

    Yost, Brandon; Cushing, Scott; Wu, Nianqiang; Bristow, Alan

    2015-03-01

    Nitrogen doping was reported to extend lanthanum dititanate's (LTO), La2Ti2O7, absorption from 380 nm to 500 nm by narrowing the band gap without introducing trap states. N-LTO holds promise for solar water splitting if, unlike in N-doped TiO2, spectral coverage can be increased without decreasing carrier lifetimes and decrementing the overall performance. Therefore, in this presentation, the effect of N-doping on LTO is confirmed using transient absorption spectroscopy with a supercontinuum and THz probe. The supercontinuum probe reveals carrier evolution in both band edge and mid-gap defect states. By exciting above and below the band edge, the influence of N-doping on the density of trap states is directly compared to the band edge position. Further, comparison of dynamics measured with the supercontinuum and THz probes reveals which changes in lifetime correspond to increased mobility or increased trapping, showing how the shifted band edge modifies carrier dynamics, and that N-doping in LTO is an efficient strategy for solar energy harvesting.

  14. The role of school performance in narrowing gender gaps in the formation of STEM aspirations: a cross-national study

    PubMed Central

    Mann, Allison; Legewie, Joscha; DiPrete, Thomas A.

    2015-01-01

    This study uses cross-national evidence to estimate the effect of school peer performance on the size of the gender gap in the formation of STEM career aspirations. We argue that STEM aspirations are influenced not only by gender stereotyping in the national culture but also by the performance of peers in the local school environment. Our analyses are based on the Program for International Student Assessment (PISA). They investigate whether 15-year-old students from 55 different countries expect to have STEM jobs at the age of 30. We find considerable gender differences in the plans to pursue careers in STEM occupations in all countries. Using PISA test scores in math and science aggregated at the school level as a measure of school performance, we find that stronger performance environments have a negative impact on student career aspirations in STEM. Although girls are less likely than boys to aspire to STEM occupations, even when they have comparable abilities, boys respond more than girls to competitive school performance environments. As a consequence, the aspirations gender gap narrows for high-performing students in stronger performance environments. We show that those effects are larger in countries that do not sort students into different educational tracks. PMID:25762961

  15. The Academic Achievement Gap between African American and White Students: An Exploratory Study on Reading Achievement and Intrinsic Motivation

    ERIC Educational Resources Information Center

    Herron-McCoy, La-Monica

    2009-01-01

    The purpose of this study was to explore the academic achievement gap between upper elementary African American and White students. This study sought to assess any relationships between whether academic reading, students attitudes toward reading, and academic intrinsic motivation related to ethnicity. This study also sought to assess whether…

  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. [Good agricultural practice (GAP) of Chinese materia medica (CMM) for ten years: achievements, problems and proposals].

    PubMed

    Guo, Lan-Ping; Zhang, Yan; Zhu, Shou-Dong; Wang, Gui-Hua; Wang, Xiu; Zhang, Xiao-Bo; Chen, Mei-Lan; He, Ya-Li; Han, Bang-Xing; Chen, Nai-Fu; Huang, Lu-Qi

    2014-04-01

    This paper aims to summarize the achievements during the implementation process of good agricultural practice (GAP) in Chinese Materia Medica (CMM), and on basis of analyzing the existing problems of GAP, to propose further implementation of GAP in TCM growing. Since the launch of GAP in CMM growing ten years ago, it has acquired great achievements, including: (1) The promulgation of a series of measures for the administration of the GAP approval in the CMM growing; (2) The expanded planting area of CMM; (3) The increased awareness of standardized CMM growing among farmers and enterprises; (4) The establishment of GAP implementation bases for CMM growing; (5) The improvement of theory and methodology for CMM growing; (6) The development of a large group of experts and scholars in GAP approval for CMM production. The problems existing in the production include: (1) A deep understanding of GAP and its certification is still needed; (2) The distribution of the certification base is not reasonable; (3) The geo-economics effect and the backward farming practices are thought to be the bottlenecks in the standardization of CMM growing and the scale production of CMM; (4) Low comparative effectiveness limits the development of the GAP; (5) The base of breeding improved variety is blank; (6) The immature of the cultivation technique lead to the risk of production process; (7) The degradation of soil microbial and the continuous cropping obstacle restrict the sustainable development of the GAP base. To further promote the health and orderly GAP in the CMM growing, the authors propose: (1) To change the mode of production; (2) To establish a sound standard system so as to ensure quality products for fair prices; (3) To fully consider the geo-economic culture and vigorously promote the definite cultivating of traditional Chinese medicinal materials; (4) To strengthen the transformation and generalization of basic researches and achievements, in order to provide technical

  18. Why Pre-K Is Critical to Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Frede, Ellen; Barnett, W. Steven

    2011-01-01

    The recently released results of the 2009 Program for International Student Assessment (PISA) comparison of educational achievement across 65 countries has brought renewed attention to the achievement gap and recommended changes to improve U.S. performance. The U.S. was well down in the middle of the pack for reading, math, and science while…

  19. Examining the Effectiveness of Closing the Achievement Gap Professional Development Demonstration Schools

    ERIC Educational Resources Information Center

    White, Larry J.; Hixson, Nate; Hammer, Patricia Cahape; Smith, Diana L.; D'Brot, Juan

    2010-01-01

    A study examined the impact of the "Closing the Achievement Gap" (CAG schools) program on the academic achievement of students in 30 schools serving high percentages of African American and economically disadvantaged students in West Virginia (WV), 2004-2008. The program assigned experienced educators, "CAG liaisons", to the schools to provide…

  20. Science Achievement Gaps Begin Very Early, Persist, and Are Largely Explained by Modifiable Factors

    ERIC Educational Resources Information Center

    Morgan, Paul L.; Farkas, George; Hillemeier, Marianne M.; Maczuga, Steve

    2016-01-01

    We examined the age of onset, over-time dynamics, and mechanisms underlying science achievement gaps in U.S. elementary and middle schools. To do so, we estimated multilevel growth models that included as predictors children's own general knowledge, reading and mathematics achievement, behavioral self-regulation, sociodemographics, other child-…

  1. Rural-Urban Gaps in Academic Achievement, Schooling Conditions, Student, and Teachers' Characteristics in Pakistan

    ERIC Educational Resources Information Center

    Tayyaba, Saadia

    2012-01-01

    Purpose: Recent educational research has demonstrated rural-urban gaps in achievement and schooling conditions. Evidence from developing countries is still sparse. This study seeks to report rural-urban disparities in achievement, student, teacher, and school characteristics based on a nationally representative sample of grade four students from…

  2. Language Diversity, School Learning, and Closing Achievement Gaps: A Workshop Summary

    ERIC Educational Resources Information Center

    Welch-Ross, Melissa

    2010-01-01

    The Workshop on the Role of Language in School Learning: Implications for Closing the Achievement Gap was held to explore three questions: What is known about the conditions that affect language development? What are the effects of early language development on school achievement? What instructional approaches help students meet school demands for…

  3. Understanding Science Achievement Gaps by Race/Ethnicity and Gender in Kindergarten and First Grade

    ERIC Educational Resources Information Center

    Curran, F. Chris; Kellogg, Ann T.

    2016-01-01

    Disparities in science achievement across race and gender have been well documented in secondary and postsecondary school; however, the science achievement gap in the early years of elementary school remains understudied. We present findings from the recently released Early Childhood Longitudinal Study, Kindergarten Class of 2010-2011 that…

  4. Closing the Achievement Gap in El Paso: A Collaboration for K-16 Renewal.

    ERIC Educational Resources Information Center

    Navarro, M. Susana; Natalicio, Diana S.

    1999-01-01

    To close the Anglo/ethnic minority achievement gap, 11 education and community leaders formed the El Paso Collaborative for Academic Excellence. Two goals were paramount: ensuring success among K-16 youngsters in area educational institutions and ensuring all high-school graduates' readiness for college. The program achieved impressive results.…

  5. The Impact of Neighborhood Disadvantage on the Black-White Achievement Gap

    ERIC Educational Resources Information Center

    Lee, Moosung; Madyun, Na'im

    2009-01-01

    Contextual analysis of the achievement gap has gained much momentum within the last few decades. This study furthers the discourse by examining the applicability of 2 sociological contextual development approaches on achievement. We analyzed 79 neighborhoods organized by the level of crime and poverty from both a social disorganization and social…

  6. Turnaround in Texas: How One District Closed Its Minority Achievement Gap.

    ERIC Educational Resources Information Center

    Cook, Glenn

    2003-01-01

    Describes how one district closed its minority achievement gap by employing the Brazosport model, a combination of effective-schools research and Total Quality Management principles. The model includes an eight-step "plan-do-check" instructional cycle for teachers and emphasizes teacher training and tracking data. Student-achievement data, not the…

  7. Atomic and electronic structures evolution of the narrow band gap semiconductor Ag2Se under high pressure.

    PubMed

    Naumov, P; Barkalov, O; Mirhosseini, H; Felser, C; Medvedev, S A

    2016-09-28

    Non-trivial electronic properties of silver telluride and other chalcogenides, such as the presence of a topological insulator state, electronic topological transitions, metallization, and the possible emergence of superconductivity under pressure have attracted attention in recent years. In this work, we studied the electronic properties of silver selenide (Ag2Se). We performed direct current electrical resistivity measurements, in situ Raman spectroscopy, and synchrotron x-ray diffraction accompanied by ab initio calculations to explore pressure-induced changes to the atomic and electronic structure of Ag2Se. The temperature dependence of the electrical resistivity was measured up to 30 GPa in the 4-300 K temperature interval. Resistivity data showed an unusual increase in the thermal energy gap of phase I, which is a semiconductor under ambient conditions. Recently, a similar effect was reported for the 3D topological insulator Bi2Se3. Raman spectroscopy studies revealed lattice instability in phase I indicated by the softening of observed vibrational modes with pressure. Our hybrid functional band structure calculations predicted that phase I of Ag2Se would be a narrow band gap semiconductor, in accordance with experimental results. At a pressure of ~7.5 GPa, Ag2Se underwent a structural transition to phase II with an orthorhombic Pnma structure. The temperature dependence of the resistivity of Ag2Se phase II demonstrated its metallic character. Ag2Se phase III, which is stable above 16.5 GPa, is also metallic according to the resistivity data. No indication of the superconducting transition is found above 4 K in the studied pressure range. PMID:27439023

  8. Atomic and electronic structures evolution of the narrow band gap semiconductor Ag2Se under high pressure

    NASA Astrophysics Data System (ADS)

    Naumov, P.; Barkalov, O.; Mirhosseini, H.; Felser, C.; Medvedev, S. A.

    2016-09-01

    Non-trivial electronic properties of silver telluride and other chalcogenides, such as the presence of a topological insulator state, electronic topological transitions, metallization, and the possible emergence of superconductivity under pressure have attracted attention in recent years. In this work, we studied the electronic properties of silver selenide (Ag2Se). We performed direct current electrical resistivity measurements, in situ Raman spectroscopy, and synchrotron x-ray diffraction accompanied by ab initio calculations to explore pressure-induced changes to the atomic and electronic structure of Ag2Se. The temperature dependence of the electrical resistivity was measured up to 30 GPa in the 4–300 K temperature interval. Resistivity data showed an unusual increase in the thermal energy gap of phase I, which is a semiconductor under ambient conditions. Recently, a similar effect was reported for the 3D topological insulator Bi2Se3. Raman spectroscopy studies revealed lattice instability in phase I indicated by the softening of observed vibrational modes with pressure. Our hybrid functional band structure calculations predicted that phase I of Ag2Se would be a narrow band gap semiconductor, in accordance with experimental results. At a pressure of ~7.5 GPa, Ag2Se underwent a structural transition to phase II with an orthorhombic Pnma structure. The temperature dependence of the resistivity of Ag2Se phase II demonstrated its metallic character. Ag2Se phase III, which is stable above 16.5 GPa, is also metallic according to the resistivity data. No indication of the superconducting transition is found above 4 K in the studied pressure range.

  9. Preparation of narrow band gap V2O5/TiO2 composite films by micro-arc oxidation

    NASA Astrophysics Data System (ADS)

    Luo, Qiang; Li, Xin-wei; Cai, Qi-zhou; Yan, Qing-song; Pan, Zhen-hua

    2012-11-01

    V2O5/TiO2 composite films were prepared on pure titanium substrates via micro-arc oxidation (MAO) in electrolytes consisting of NaVO3. Their morphology and elements were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. Phase composition and valence states of species in the films were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS) were also employed to evaluate the photophysical property of the films. The V2O5/TiO2 composite films show a sheet-like morphology. Not only V2O5 phase appears in the films when the NaVO3 concentration of the electrolyte is higher than 6.10 g/L and is loaded at the surface of anatase, but also V4+ is incorporated into the crystal lattice of anatase. In comparison with pure TiO2 films the V2O5/TiO2 composite films exhibit significantly narrow band gap energy. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the narrowest band gap energy, which is approximately 1.89 eV. The V2O5/TiO2 composite films also have the significantly enhanced visible light photocatalytic activity. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the best photocatalytic activity and about 93% of rhodamine is degraded after 14 h visible light radiation.

  10. Narrow gap laser welding

    DOEpatents

    Milewski, J.O.; Sklar, E.

    1998-06-02

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

  11. Narrow gap laser welding

    DOEpatents

    Milewski, John O.; Sklar, Edward

    1998-01-01

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

  12. Policy, Leadership, and Student Achievement: Implications for Urban Communities. The Achievement Gap, Research, Practice, and Policy

    ERIC Educational Resources Information Center

    McGuire, C. Kent, Ed.; Ikpa, Vivian W., Ed.

    2008-01-01

    This is the second book in the series examining student achievement. The chapters in this book reflect the scholarly papers presented at the July 2006 Education Policy, Leadership Summer Institute (EPLSI) by K-16 educators, researchers, community advocates, and policymakers who work in urban communities. The Institute serves as a place where…

  13. Closing the Achievement Gap: Impact of Inclusion upon Achievement Rates of Students with Special Needs

    ERIC Educational Resources Information Center

    Black, Kathleen

    2010-01-01

    The purpose of this research study was to examine the relationship between the amount of time a student with special needs spends in the inclusive classroom and their achievement passing rates in mathematics and reading. TAKS passing rates for mathematics and reading for third graders in 2007-2008, and the same cohort of fourth graders in…

  14. Empirical determination of the energy band gap narrowing in p{sup +} silicon heavily doped with boron

    SciTech Connect

    Yan, Di Cuevas, Andres

    2014-11-21

    In the analysis of highly doped silicon, energy band gap narrowing (BGN) and degeneracy effects may be accounted for separately, as a net BGN in conjunction with Fermi-Dirac statistics, or lumped together in an apparent BGN used with Boltzmann statistics. This paper presents an experimental study of silicon highly doped with boron, with the aim of evaluating the applicability of previously reported BGN models. Different boron diffusions covering a broad range of dopant densities were prepared, and their characteristic recombination current parameters J{sub 0} were measured using a contactless photoconductance technique. The BGN was subsequently extracted by matching theoretical simulations of carrier transport and recombination in each of the boron diffused regions and the measured J{sub 0} values. An evaluation of two different minority carrier mobility models indicates that their impact on the extraction of the BGN is relatively small. After considering possible uncertainties, it can be concluded that the BGN is slightly larger in p{sup +} silicon than in n{sup +} silicon, in qualitative agreement with theoretical predictions by Schenk. Nevertheless, in quantitative terms that theoretical model is found to slightly underestimate the BGN in p{sup +} silicon. With the two different parameterizations derived in this paper for the BGN in p{sup +} silicon, both statistical approaches, Boltzmann and Fermi-Dirac, provide a good agreement with the experimental data.

  15. Wave Function Mixing and g-Factors in Narrow Gap Ferromagnetic III-V Dilute Magnetic Semiconductors

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Sanders, G. D.; Stanton, C. J.

    2002-03-01

    We present a theory for wave-function mixing and g-factors in ferromagnetic p-doped narrow gap In_1-xMn_xAs dilute magnetic semiconductor alloys in an ultrahigh external magnetic field, B. We generalize an 8 band Pidgeon-Brown model to include (i) the wavevector, k, dependence of the electronic states along B, (ii) s-d and p-d exchange interactions with localized Mn d-electrons, and (iii) finite magnetic moment in the ferromagnetic state. The complex valence band structure at finite k plays an important role in the cyclotron resonance spectra. We look at the band-mixing and spin-dependence of the wave functions as a function of the wavevector, magnetic field (0-100T), temperature (4 K to 290 K), and Mn concentration (0 to 12 %). From this, we can extract magnetic field dependent g-factors. The sensitivity of the band mixing and g-factors to the s-d and p-d exchange interactions is also investigated. Finally, we look at the effect of band-mixing on optical properties such as the polarization dependence of the absorption and luminescence.

  16. New high Tc multiferroics KBiFe2O5 with narrow band gap and promising photovoltaic effect

    PubMed Central

    Zhang, Ganghua; Wu, Hui; Li, Guobao; Huang, Qingzhen; Yang, Chongyin; Huang, Fuqiang; Liao, Fuhui; Lin, Jianhua

    2013-01-01

    Intrinsic polarization of ferroelectrics (FE) helps separate photon-generated charge carriers thus enhances photovoltaic effects. However, traditional FE with transition-metal cations (M) of d0 electron in MO6 network typically has a band gap (Eg) exceeding 3.0 eV. Although a smaller Eg (2.6 eV) can be obtained in multiferroic BiFeO3, the value is still too high for optimal solar energy applications. Computational “materials genome” searches have predicted several exotic MO6 FE with Eg < 2.0 eV, all thus far unconfirmed because of synthesis difficulties. Here we report a new FE compound with MO4 tetrahedral network, KBiFe2O5, which features narrow Eg (1.6 eV), high Curie temperature (Tc ~ 780 K) and robust magnetic and photoelectric activities. The high photovoltage (8.8 V) and photocurrent density (15 μA/cm2) were obtained, which is comparable to the reported BiFeO3. This finding may open a new avenue to discovering and designing optimal FE compounds for solar energy applications. PMID:23405279

  17. Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts

    SciTech Connect

    Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

    2009-06-07

    We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

  18. Closing the achievement gap: the association of racial climate with achievement and behavioral outcomes.

    PubMed

    Mattison, Erica; Aber, Mark S

    2007-09-01

    This study investigated the relationship between school racial climate and students' self-reports of academic and discipline outcomes, including whether racial climate mediated and/or moderated the relationship between race and outcomes. Using the Racial Climate Survey-High School Version (M. Aber et al., unpublished), data were gathered from African American (n = 382) and European American students (n = 1456) regarding their perceptions of racial climate. About 18% of the respondents were low-income and approximately 50% were male. Positive perceptions of the racial climate were associated with higher student achievement and fewer discipline problems. Further, race moderated the relationship between racial climate and both achievement and discipline outcomes. Finally, racial differences in students' grades and discipline outcomes were associated with differences in perceptions of racial climate. Results suggest careful attention should be given to the racial climate of secondary schools, particularly for adolescents who perceive schools as unfair. PMID:17587175

  19. Narrowing the Gap in Outcomes: Further Overview of Data and Evidence on the ECM Outcomes for Vulnerable Groups. Progress Report and Update

    ERIC Educational Resources Information Center

    Morris, Marian; Easton, Claire

    2008-01-01

    Narrowing the Gap (NtG) is a two-year development and research programme, funded by the Department for Children, Schools and Families (DCSF) and the Local Government Association (LGA), working in partnership with other agencies, including local authorities. It seeks to make a significant difference, on a national scale, to the performance of…

  20. A volume pulsed corona formed during nanosecond pulsed periodic discharge of negative polarity in narrow gaps with airflow at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Lepekhin, N. M.; Priseko, Yu. S.; Puresev, N. I.; Filippov, V. G.

    2014-06-01

    A volume mode of spatially homogeneous nanosecond pulsed-periodic corona discharge of negative polarity has been obtained using an edge-to-edge electrode geometry in narrow gaps with airflow at atmospheric pressure and natural humidity. The parameters of discharge are estimated, and a factor limiting the power deposited in discharge is determined.

  1. The Black-White Scoring Gap on SAT II Achievement Tests: Some of the News Is Cheering.

    ERIC Educational Resources Information Center

    Journal of Blacks in Higher Education, 2003

    2003-01-01

    Academically accomplished applicants to the nation's top colleges usually take SAT II Achievement Tests. While scoring gaps between college-bound Blacks and Whites on these tests tend to be smaller than gaps on the basic SAT, a racial scoring gap persists. However, black students appear to be making progress in closing the racial scoring gap on…

  2. Harming the Best: How Schools Affect the Black-White Achievement Gap. NBER Working Paper No. 14211

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Rivkin, Steven G.

    2008-01-01

    Sizeable achievement differences by race appear in early grades, but substantial uncertainty exists about the impact of school quality on the black-white achievement gap and particularly about its evolution across different parts of the achievement distribution. Texas administrative data show that the overall growth in the achievement gap between…

  3. Closing the Achievement Gap between African American Children and their Caucasians Counterparts Using Collaboration Learning Setting

    ERIC Educational Resources Information Center

    Mubenga, Pascal T.

    2006-01-01

    The underachievement of a large and growing scale of African American children is nothing short of national crisis, according to Haycock (2001) in her research on closing the achievement gap. Haycock indicates that by the year 2010, Black and Hispanics will compromise approximately fifty percent of the school population. This is an alarming…

  4. Closing the Gap in Academic Readiness and Achievement: The Role of Early Childcare

    ERIC Educational Resources Information Center

    Geoffroy, Marie-Claude; Cote, Sylvana. M.; Giguere, Charles-Edouard; Dionne, Ginette; Zelazo, Philip David; Tremblay, Richard E.; Boivin, Michel; Seguin, Jean. R.

    2010-01-01

    Background: Socially disadvantaged children with academic difficulties at school entry are at increased risk for poor health and psychosocial outcomes. Our objective is to test the possibility that participation in childcare--at the population level--could attenuate the gap in academic readiness and achievement between children with and without a…

  5. The Impact of Early Childhood Education upon the Black-White Achievement Gap

    ERIC Educational Resources Information Center

    Zane, Linda M.

    2009-01-01

    It can be argued that the current Black-White achievement gap provides evidence for a long-standing history of racial inequity within American society, as well as an informative barometer of progress toward educational parity. By all accounts, the measurements registered by this barometer continue to be cause for alarm. The disturbing Black-White…

  6. A Critical Race Analysis of the Achievement Gap in the United States: Politics, Reality, and Hope

    ERIC Educational Resources Information Center

    Taylor, Edward

    2006-01-01

    Federal educational legislation in the United States has focused increased attention on the racial achievement gap between minority and majority students. The No Child Left Behind (NCLB) legislation has forced high-stakes accountability in public schools, with the assumption that these policies will create performance pressures on schools to…

  7. Urban School Achievement Gap as a Metaphor to Conceal U.S. Apartheid Education

    ERIC Educational Resources Information Center

    Cross, Beverly E.

    2007-01-01

    This article uses the metaphor of the achievement gap to make transparent, discuss, and critique the analytical frame/lens used in the articles to analyze urban education. Doing such an analysis is essential to producing an additional lens that has utility in theory and practice. It facilitates a historical analysis of urban education and leads to…

  8. The Role of Planning Skills in the Income-Achievement Gap

    ERIC Educational Resources Information Center

    Crook, Stephen R.; Evans, Gary W.

    2014-01-01

    The pervasive income-achievement gap has been attributed in part to deficiencies in executive functioning (EF). The development of EF is related to children's planning ability, an aspect of development that has received little attention. Longitudinal data from the National Institute of Child Health and Human Development study of early child…

  9. Effects of Single-Sex and Coeducational Schooling on the Gender Gap in Educational Achievement

    ERIC Educational Resources Information Center

    Gibb, Sheree J.; Fergusson, David M.; Horwood, L. John

    2008-01-01

    This study examined the effects of single-sex and coeducational schooling on the gender gap in educational achievement to age 25. Data were drawn from the Christchurch Health and Development Study, a longitudinal study of a birth cohort of 1265 individuals born in 1977 in Christchurch, New Zealand. After adjustment for a series of covariates…

  10. The White British-Black Caribbean Achievement Gap: Tests, Tiers and Teacher Expectations

    ERIC Educational Resources Information Center

    Strand, Steve

    2012-01-01

    A recent analysis of the Longitudinal Study of Young People in England (LSYPE) indicates a White British-Black Caribbean achievement gap at age 14 which cannot be accounted for by socio-economic variables or a wide range of contextual factors. This article uses the LSYPE to analyse patterns of entry to the different tiers of national mathematics…

  11. Web-Based Interactive System for Analyzing Achievement Gaps in Public Schools System

    ERIC Educational Resources Information Center

    Wang, Kening; Mulvenon, Sean W.; Stegman, Charles; Xia, Yanling

    2010-01-01

    The National Office for Research on Measurement and Evaluation Systems (NORMES) at the University of Arkansas developed a web-based interactive system to provide information on state, district, and school level achievement gaps between white students and black students, socioeconomically disadvantaged students and non-disadvantaged students, male…

  12. Beyond Popular Cultural and Structural Arguments: Imagining a Compass to Guide Burgeoning Urban Achievement Gap Scholars

    ERIC Educational Resources Information Center

    Hughes, Sherick A.; North, Connie E.

    2012-01-01

    This manuscript begins by distinguishing the common structural and cultural arguments that tend to guide popular urban achievement gap research. It highlights Jencks and Phillips, and Payne, as two cases of popular texts followed by critical responses to them. It concludes by imagining a compass to guide burgeoning scholars toward reading into…

  13. Estimating Achievement Gaps from Test Scores Reported in Ordinal "Proficiency" Categories

    ERIC Educational Resources Information Center

    Ho, Andrew D.; Reardon, Sean F.

    2012-01-01

    Test scores are commonly reported in a small number of ordered categories. Examples of such reporting include state accountability testing, Advanced Placement tests, and English proficiency tests. This article introduces and evaluates methods for estimating achievement gaps on a familiar standard-deviation-unit metric using data from these ordered…

  14. Facing up to Realities: Harvard Economist Investigates the Racial Achievement Gap

    ERIC Educational Resources Information Center

    Roach, Ronald

    2004-01-01

    As an economist, Dr. Ronald F. Ferguson often applies quantitative analysis to public policy dilemmas, which yields data models and quantitative measures of complex issues. In tackling the racial achievement gap, the Harvard-based social policy expert has added investigation techniques from sociology and psychology to explore what might seem a…

  15. Cambodian Invisibility: Students Lost between the "Achievement Gap" and the "Model Minority"

    ERIC Educational Resources Information Center

    Wallitt, Roberta

    2008-01-01

    This article discusses one aspect of a research study that explored the school experiences of Cambodian American students. Due to their invisibility in the school setting and also in the literature on school reform, these children from refugee families are often overlooked as schools attempt to "close the achievement gap." Through their own words,…

  16. Closing the Obesity Achievement Gap: Evidence-Based Practices that School Counselors Can Help Implement

    ERIC Educational Resources Information Center

    Perusse, Rachelle; Kailimang, Lukas; Krell, Megan

    2009-01-01

    School counselors are charged with helping students in the personal/social, academic, and career development domains. Obesity creates adverse educational outcomes for students along these three domains, suggesting an obesity achievement gap. Thus, school counselors can benefit from knowing which interventions have been shown to be successful in…

  17. Gender Gaps in Mathematics, Science and Reading Achievements in Muslim Countries: A Quantile Regression Approach

    ERIC Educational Resources Information Center

    Shafiq, M. Najeeb

    2013-01-01

    Using quantile regression analyses, this study examines gender gaps in mathematics, science, and reading in Azerbaijan, Indonesia, Jordan, the Kyrgyz Republic, Qatar, Tunisia, and Turkey among 15-year-old students. The analyses show that girls in Azerbaijan achieve as well as boys in mathematics and science and overachieve in reading. In Jordan,…

  18. Teachers and the Gender Gaps in Student Achievement. NBER Working Paper No. 11660

    ERIC Educational Resources Information Center

    Dee, Thomas S.

    2005-01-01

    In the United States, girls outperform boys in measures of reading achievement while generally underperforming in science and mathematics. One major class of explanations for these gaps involves the gender-based interactions between students and teachers (e.g., role-model and Pygmalion effects). However, the evidence on whether these interactions…

  19. Gender Gaps in Mathematics, Science and Reading Achievements in Muslim Countries: Evidence from Quantile Regression Analyses

    ERIC Educational Resources Information Center

    Shafiq, M. Najeeb

    2011-01-01

    Using quantile regression analyses, this study examines gender gaps in mathematics, science, and reading in Azerbaijan, Indonesia, Jordan, the Kyrgyz Republic, Qatar, Tunisia, and Turkey among 15 year-old students. The analyses show that girls in Azerbaijan achieve as well as boys in mathematics and science and overachieve in reading. In Jordan,…

  20. Addressing the Achievement Gap and Disproportionality through the Use of Culturally Responsive Teaching Practices

    ERIC Educational Resources Information Center

    Griner, Angela Christine; Stewart, Martha Lue

    2013-01-01

    Culturally responsive practices in schools and classrooms have been shown to be an effective means of addressing the achievement gap as well as the disproportionate representation of racially, culturally, ethnically, and linguistically diverse students in programs serving students with special needs. While there has been much research discussing…

  1. The Role of the Superintendent in Closing the Achievement Gap in Diverse Small School Districts

    ERIC Educational Resources Information Center

    Wright, Howell, Jr.

    2009-01-01

    The purpose of this research is to examine the superintendent's role in closing the achievement gap in a culturally diverse rural school district. This topic is especially important and timely as accountability for student and school success appears to have a national focus. The literature within the last 15 years indicates consistent methods of…

  2. Bridging the Great Divide: Broadening Perspectives on Closing the Achievement Gaps.

    ERIC Educational Resources Information Center

    Viewpoints, 2002

    2002-01-01

    This booklet presents information on the achievement gaps in education between white, Asian, and economically advantaged students and their African American, Hispanic, Native American, and economically disadvantaged peers. It provides examples from higher education, district, and school levels and summarizes available resources and tools to help…

  3. Closing the Achievement Gap: Principles for Improving the Educational Success of All Students. ERIC Digest.

    ERIC Educational Resources Information Center

    Schwartz, Wendy

    This digest reviews educational policies and practices that have been proven effective in closing the achievement gap, offering a list of resources with detailed information about them. The digest focuses on state and district roles (e.g., developing and implementing educational goals, rigorous standards, and accountability standards and providing…

  4. Strategic Funding Attracts Co-Investment. Closing the Achievement Gap Series

    ERIC Educational Resources Information Center

    Read, Tory

    2008-01-01

    The "Closing the Achievement Gap" series explores the Casey Foundation's education investments and presents stories, results, and lessons learned. An objective of every education investment at the Annie E. Casey Foundation is to attract co-investment in promising and evidence-based programs and policies. One way the Foundation does this is to…

  5. Examining the Achievement Test Score Gap between Urban and Suburban Students

    ERIC Educational Resources Information Center

    Sandy, Jonathan; Duncan, Kevin

    2010-01-01

    Data from the National Longitudinal Survey of Labor Market Experience for Youth (1997 cohort) are used to examine the urban school achievement gap. Specifically, we use the Blinder-Oaxaca technique to decompose differences in Armed Services Vocational Aptitude Battery scores for students who attended urban and suburban schools. We find that…

  6. In Their Own Voices: Adolescent African American Males' Experiences of the Achievement Gap

    ERIC Educational Resources Information Center

    Moon, Natasha S.; Singh, Anneliese A.

    2015-01-01

    The authors use a phenomenological research tradition grounded in CRT tenets to describe the daily lived experiences that 12 male African American youth had in relation to the achievement gap. Researchers collected individual semi-structured interviews and focus group data related to the study phenomenon. There were five themes identified in…

  7. School Composition and the Black-White Achievement Gap: Methodology Companion. NCES 2015-032

    ERIC Educational Resources Information Center

    Bohrnstedt, G.; Kitmitto, S.; Ogut, B.; Sherman, D.; Chan, D.

    2015-01-01

    The School Composition and the Black-White Achievement Gap study was undertaken by the National Center for Education Statistics to present both descriptive and associative information on the relationships among the percentage of students in a school who were Black (referred to as "Black student density" or "density"), the…

  8. Teacher Perceptions about Diversity and the Achievement Gap: Understanding the Discursive Construction of Whiteness

    ERIC Educational Resources Information Center

    Padilla Vigil, Virginia

    2013-01-01

    Teacher perceptions about diversity and the achievement gap were examined. Participants were alternative teacher licensure candidates at the student teaching phase of their preparation program. Two-hour individual, in-depth, and semi-structured interviews were conducted with each of the participants. Additionally, the participants participated in…

  9. Reducing the Achievement Gap through District/Union Collaboration: The Tale of Two School Districts

    ERIC Educational Resources Information Center

    Rice, George Ann

    2007-01-01

    In looking for examples of districts that were making gains both in assuring teacher quality and in reducing gaps in student achievement, researchers continually came to Clark County, Nevada and Hamilton County, Tennessee. While the road to reform and the specific steps each district took were different, they shared a fundamental element--in both…

  10. Trends in Academic Achievement Gaps in the Era of No Child Left Behind

    ERIC Educational Resources Information Center

    Reardon, Sean F.; Greenberg, Erica; Kalogrides, Demetra; Shores, Kenneth A.; Valentino, Rachel A.

    2012-01-01

    The authors' goals in this study are to use both the National Assessment of Educational Progress (NAEP) and state accountability test score data to (1) provide a detailed description of the magnitude and trends of state-level academic achievement gaps among cohorts of students entering school in the 1990s and 2000s; (2) investigate the extent to…

  11. Are Two Better than One? A Comparative Study of Achievement Gaps and Family Structure

    ERIC Educational Resources Information Center

    Hampden-Thompson, Gillian

    2009-01-01

    Using data from the Program for International Student Assessment (PISA), the size of the literacy achievement gap between 15-year-old students from two-parent and those from single-mother households were compared across 18 industrialized nations. This study found that cross-national differences exist in the association between single motherhood…

  12. More than Sanctions: Closing Achievement Gaps through California's Use of Intensive Technical Assistance

    ERIC Educational Resources Information Center

    Strunk, Katharine O.; McEachin, Andrew

    2014-01-01

    One of the enduring problems in education is the persistence of achievement gaps between White, wealthy, native English-speaking students and their counterparts who are minority, lower-income, or English language learners. This study shows that one intensive technical assistance (TA) intervention--California's District Assistance and…

  13. Providing Early Childhood Teachers with Opportunities to Understand Diversity and the Achievement Gap

    ERIC Educational Resources Information Center

    Meece, Darrell; Wingate, Kimberly O'Kelley

    2010-01-01

    High quality teaching--providing children with support, feedback, and positive communication--is associated with closing the achievement gap between minority and majority children. It is important for students in teacher preparation programs to understand changes in curricular approaches to diversity--from the color-blind approach, to…

  14. School-University Partnerships for Closing the Achievement Gap: Ethical Concerns

    ERIC Educational Resources Information Center

    Catelli, Linda A.

    2006-01-01

    Purpose: The purpose of this paper is three-fold. First, the historical phases of the school-university partnership movement and its potential for closing the achievement gap is described. Second, is to have schools and universities recognize their ethical obligation to act as partners in meeting this challenge, and subsequently to develop…

  15. Promoting Cultural Responsiveness and Closing the Achievement Gap with Standards Blending

    ERIC Educational Resources Information Center

    Schellenberg, Rita; Grothaus, Timothy

    2009-01-01

    In this article, "standards blending"--the integration of core academic and school counseling standards--is demonstrated as a culturally responsive strategy to assist in closing the achievement gap for a group of third-grade African American males. The small-group intervention described resulted in knowledge gains in both the school counseling and…

  16. Effects of Interim Assessments on the Achievement Gap: Evidence from an Experiment

    ERIC Educational Resources Information Center

    Konstantopoulos, Spyros; Li, Wei; Miller, Shazia; van der Ploeg, Arie

    2015-01-01

    Motivated by the passage of the No Child Left Behind (NCLB) Act, all states operate accountability systems that measure and report school and student performance annually. The purpose of this study is to examine the effects of interim assessments on the achievement gap. The authors examine the impact of interim assessments throughout the…

  17. School Counseling to Close the Achievement Gap: A Social Justice Framework for Success

    ERIC Educational Resources Information Center

    Holcomb-McCoy, Cheryl

    2007-01-01

    School counselors can play a powerful role in closing the achievement gap when they incorporate the principles of social justice into their practice. In this much-needed resource for preservice and inservice counselors, the author addresses factors (such as racism, sexism, heterosexism, and classism) that can contribute to academic failure, and…

  18. The role of planning skills in the income-achievement gap.

    PubMed

    Crook, Stephen R; Evans, Gary W

    2014-01-01

    The pervasive income-achievement gap has been attributed in part to deficiencies in executive functioning (EF). The development of EF is related to children's planning ability, an aspect of development that has received little attention. Longitudinal data from the National Institute of Child Health and Human Development study of early child care show that early childhood poverty (1 and 24 months) is significantly related to fifth grade, math, and reading achievement (n = 1,009). The ability to plan in Grade 3, indexed by the Tower of Hanoi task, mediates the income-achievement gap in math and to a lesser extent in reading. IQ was incorporated as a statistical control throughout. PMID:23815401

  19. Achieving Health Equity: Closing The Gaps In Health Care Disparities, Interventions, And Research.

    PubMed

    Purnell, Tanjala S; Calhoun, Elizabeth A; Golden, Sherita H; Halladay, Jacqueline R; Krok-Schoen, Jessica L; Appelhans, Bradley M; Cooper, Lisa A

    2016-08-01

    In the United States, racial/ethnic minority, rural, and low-income populations continue to experience suboptimal access to and quality of health care despite decades of recognition of health disparities and policy mandates to eliminate them. Many health care interventions that were designed to achieve health equity fall short because of gaps in knowledge and translation. We discuss these gaps and highlight innovative interventions that help address them, focusing on cardiovascular disease and cancer. We also provide recommendations for advancing the field of health equity and informing the implementation and evaluation of policies that target health disparities through improved access to care and quality of care. PMID:27503965

  20. Narrowing the Achievement Gap in a (Re) Segregated Urban School District: Research, Policy and Practice. The Achievement Gap, Research, Practice, and Policy

    ERIC Educational Resources Information Center

    Ikpa, Vivian W.; McGuire, C. Kent

    2009-01-01

    The interplay between sociopolitical forces and economic agendas becomes apparent when one examines the June 28, 2007 United States Supreme Court Decision, Parents Involved In Community Schools v. Seattle School District . In a reversal of the 1954 Brown Decision, the United States Supreme Court ruled that public schools could not use race as a…

  1. Growth and gaps in mathematics achievement of students with and without disabilities on a statewide achievement test.

    PubMed

    Stevens, Joseph J; Schulte, Ann C; Elliott, Stephen N; Nese, Joseph F T; Tindal, Gerald

    2015-02-01

    This study estimated mathematics achievement growth trajectories in a statewide sample of 92,045 students with and without disabilities over Grades 3 to 7. Students with disabilities (SWDs) were identified in seven exceptionality categories. Students without disabilities (SWoDs) were categorized as General Education (GE) or Academically/Intellectually Gifted (AIG). Students in all groups showed significant growth that decelerated over grades as well as significant variability in achievement by student group, both at the initial assessment in Grade 3 and in rates of growth over time. Race/ethnicity, gender, parental education, free/reduced lunch status, and English language proficiency were also significant predictors of achievement. Effect size estimates showed substantial year-to-year growth that decreased over grades. Sizeable achievement gaps that were relatively stable over grades were observed between SWoDs and students in specific exceptionality categories. Our study also demonstrated the importance of statistically controlling for variation related to student demographic characteristics. Additional research is needed that expands on these results with the same and additional exceptionality groups. PMID:25636260

  2. Teacher Effects and the Achievement Gap: Do Teacher and Teaching Quality Influence the Achievement Gap between Black and White and High- and Low-SES Students in the Early Grades?

    ERIC Educational Resources Information Center

    Desimone, Laura; Long, Daniel A.

    2010-01-01

    Background/Context: Although there is relative agreement on the pattern of the achievement gap, attributing changes in the gap to schooling is less clear. Our study contributes to understanding potential teacher and teaching effects on achievement and inequality. Purpose/Objective/Research Question/Focus of Study: We intend our work to contribute…

  3. Do Peers Contribute to the Achievement Gap between Vietnamese-American and Mexican-American Adolescents?

    PubMed Central

    Duong, Mylien T.; Schwartz, David; McCarty, Carolyn A.

    2013-01-01

    Documented associations between academic and social functioning have been inconsistent. These discrepancies may reflect the moderating role of sociocultural context. In this study, we examined ethnicity and gender as moderators of this relation. We collected peer nominations, GPA from school records, and self-report questionnaires for 519 Vietnamese-American and Mexican-American middle school students (mean age = 12.7 years). Using general linear modeling, we found that academic and social functioning were more strongly and positively linked for Vietnamese-Americans relative to Mexican-Americans, and for girls relative to boys. We also examined group differences in achievement values, and found that Vietnamese-Americans were more likely to admire and be friends with high-achieving peers. The results suggest that peers provide one context in which ethnic and gender differences in achievement values emerge, and interventions aimed at reducing the achievement gap may benefit from incorporating a focus on peers. PMID:24443632

  4. Reducing the socio-economic status achievement gap at University by promoting mastery-oriented assessment.

    PubMed

    Smeding, Annique; Darnon, Céline; Souchal, Carine; Toczek-Capelle, Marie-Christine; Butera, Fabrizio

    2013-01-01

    In spite of official intentions to reduce inequalities at University, students' socio-economic status (SES) is still a major determinant of academic success. The literature on the dual function of University suggests that University serves not only an educational function (i.e., to improve students' learning), but also a selection function (i.e., to compare people, and orient them towards different positions in society). Because current assessment practices focus on the selection more than on the educational function, their characteristics fit better with norms and values shared by dominant high-status groups and may favour high-SES students over low-SES students in terms of performances. A focus on the educational function (i.e., mastery goals), instead, may support low-SES students' achievement, but empirical evidence is currently lacking. The present research set out to provide such evidence and tested, in two field studies and a randomised field experiment, the hypothesis that focusing on University's educational function rather than on its selection function may reduce the SES achievement gap. Results showed that a focus on learning, mastery-oriented goals in the assessment process reduced the SES achievement gap at University. For the first time, empirical data support the idea that low-SES students can perform as well as high-SES students if they are led to understand assessment as part of the learning process, a way to reach mastery goals, rather than as a way to compare students to each other and select the best of them, resulting in performance goals. This research thus provides a theoretical framework to understand the differential effects of assessment on the achievement of high and low-SES students, and paves the way toward the implementation of novel, theory-driven interventions to reduce the SES-based achievement gap at University. PMID:23951219

  5. First-principles study of direct and narrow band gap semiconducting β -CuGaO2

    SciTech Connect

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-04-16

    Semiconducting oxides have attracted much attention due to their great stability in air or water and the abundance of oxygen. Recent success in synthesizing a metastable phase of CuGaO2 with direct narrow band gap opens up new applications of semiconducting oxides as absorber layer for photovoltaics. Using first-principles density functional theory calculations, we investigate the thermodynamic and mechanical stabilities as well as the structural and electronic properties of the β-CuGaO2 phase. Our calculations show that the β-CuGaO2 structure is dynamically and mechanically stable. The energy band gap is confirmed to be direct at the Γ point of Brillouin zone. In conclusion, the optical absorption occurs right at the band gap edge and the density of states near the valance band maximum is large, inducing an intense absorption of light as observed in experiment.

  6. NeMeSys: a biological resource for narrowing the gap between sequence and function in the human pathogen Neisseria meningitidis

    PubMed Central

    2009-01-01

    Background Genome sequences, now available for most pathogens, hold promise for the rational design of new therapies. However, biological resources for genome-scale identification of gene function (notably genes involved in pathogenesis) and/or genes essential for cell viability, which are necessary to achieve this goal, are often sorely lacking. This holds true for Neisseria meningitidis, one of the most feared human bacterial pathogens that causes meningitis and septicemia. Results By determining and manually annotating the complete genome sequence of a serogroup C clinical isolate of N. meningitidis (strain 8013) and assembling a library of defined mutants in up to 60% of its non-essential genes, we have created NeMeSys, a biological resource for Neisseria meningitidis systematic functional analysis. To further enhance the versatility of this toolbox, we have manually (re)annotated eight publicly available Neisseria genome sequences and stored all these data in a publicly accessible online database. The potential of NeMeSys for narrowing the gap between sequence and function is illustrated in several ways, notably by performing a functional genomics analysis of the biogenesis of type IV pili, one of the most widespread virulence factors in bacteria, and by identifying through comparative genomics a complete biochemical pathway (for sulfur metabolism) that may potentially be important for nasopharyngeal colonization. Conclusions By improving our capacity to understand gene function in an important human pathogen, NeMeSys is expected to contribute to the ongoing efforts aimed at understanding a prokaryotic cell comprehensively and eventually to the design of new therapies. PMID:19818133

  7. Parental Characteristics and the Achievement Gap in Mathematics: Hierarchical Linear Modeling Analysis of Longitudinal Study of American Youth (LSAY)

    ERIC Educational Resources Information Center

    Shoraka, Mohammad; Arnold, Robert; Kim, Eun Sook; Salinitri, Geri; Kromrey, Jeffrey

    2015-01-01

    One of the most salient problems in education is the achievement gap. The researchers investigated the effects of parental education and parental occupations in science, technology, engineering, mathematics, or medical professions (STEMM) on the achievement gap in mathematics. Because students were nested within schools, two-level Hierarchical…

  8. A Case Study of After-School Activities in One School That Is Making Progress in Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Shugerman, Susan Robin

    2013-01-01

    Closing the achievement gap has been a national conversation for several decades and a priority for educators and researchers. By looking closely at one school which is showing exceptional success with closing the achievement gap for low income students and English language learners, this study seeks to understand how school personnel and parents…

  9. Decision Points and Considerations for Identifying Rural Districts That Have Closed Student Achievement Gaps. REL 2016-130

    ERIC Educational Resources Information Center

    Culbertson, Michael J.; Billig, Shelley H.

    2016-01-01

    Rural districts have long faced challenges in closing achievement gaps between subgroups of students. This brief report describes key decision points and considerations for decision-makers interested in identifying rural districts that have closed academic achievement gaps. Examining practices in these districts may suggest activities associated…

  10. Special Education--Non-Special Education Achievement Gap in Math: Effects of Reporting Methods, Analytical Techniques, and Reclassification

    ERIC Educational Resources Information Center

    Thurlow, Martha L.; Wu, Yi-Chen; Lazarus, Sheryl S.; Ysseldyke, James E.

    2016-01-01

    Federal regulations indicate that the achievement gap must be closed between subgroups, including the gap between special education and non-special education students. We explored the ways in which achievement trends are influenced by three methods of reporting (cross-sectional, cohort-static, and cohort-dynamic). We also investigated (a) the ways…

  11. A Cultural Analysis of the Achievement Gap Discourse: Challenging the Language and Labels Used in the Work of School Reform

    ERIC Educational Resources Information Center

    Carey, Roderick L.

    2014-01-01

    In this article, I critique the labels and terms used to frame practices aimed at closing the achievement gap. I examine how an unacknowledged "achievement gap Discourse" has emerged from the language that informs practices and policies of contemporary school reform. I use Gee's uppercase "Discourse" and a cultural…

  12. Reducing the gender achievement gap in college science: a classroom study of values affirmation.

    PubMed

    Miyake, Akira; Kost-Smith, Lauren E; Finkelstein, Noah D; Pollock, Steven J; Cohen, Geoffrey L; Ito, Tiffany A

    2010-11-26

    In many science, technology, engineering, and mathematics disciplines, women are outperformed by men in test scores, jeopardizing their success in science-oriented courses and careers. The current study tested the effectiveness of a psychological intervention, called values affirmation, in reducing the gender achievement gap in a college-level introductory physics class. In this randomized double-blind study, 399 students either wrote about their most important values or not, twice at the beginning of the 15-week course. Values affirmation reduced the male-female performance and learning difference substantially and elevated women's modal grades from the C to B range. Benefits were strongest for women who tended to endorse the stereotype that men do better than women in physics. A brief psychological intervention may be a promising way to address the gender gap in science performance and learning. PMID:21109670

  13. Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.; Li, Wei-Gang

    1995-01-01

    The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

  14. Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

    NASA Astrophysics Data System (ADS)

    Patterson, James D.; Li, Wei-Gang

    1995-03-01

    The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

  15. Teachers' perceptions of students' mathematics proficiency may exacerbate early gender gaps in achievement.

    PubMed

    Robinson-Cimpian, Joseph P; Lubienski, Sarah Theule; Ganley, Colleen M; Copur-Gencturk, Yasemin

    2014-04-01

    A recent wave of research suggests that teachers overrate the performance of girls relative to boys and hold more positive attitudes toward girls' mathematics abilities. However, these prior estimates of teachers' supposed female bias are potentially misleading because these estimates (and teachers themselves) confound achievement with teachers' perceptions of behavior and effort. Using data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (ECLS-K), Study 1 demonstrates that teachers actually rate boys' mathematics proficiency higher than that of girls when conditioning on both teachers' ratings of behavior and approaches to learning as well as past and current test scores. In other words, on average girls are only perceived to be as mathematically competent as similarly achieving boys when the girls are also seen as working harder, behaving better, and being more eager to learn. Study 2 uses mediation analysis with an instrumental-variables approach, as well as a matching strategy, to explore the extent to which this conditional underrating of girls may explain the widening gender gap in mathematics in early elementary school. We find robust evidence suggesting that underrating girls' mathematics proficiency accounts for a substantial portion of the development of the mathematics achievement gap between similarly performing and behaving boys and girls in the early grades. PMID:24294875

  16. Investigation of band gap narrowing in nitrogen-doped La2Ti2O7 with transient absorption spectroscopy.

    PubMed

    Yost, Brandon T; Cushing, Scott K; Meng, Fanke; Bright, Joeseph; Bas, Derek A; Wu, Nianqiang; Bristow, Alan D

    2015-12-14

    Doping a semiconductor can extend the light absorption range, however, it usually introduces mid-gap states, reducing the charge carrier lifetime. This report shows that doping lanthanum dititinate (La2Ti2O7) with nitrogen extends the valence band edge by creating a continuum of dopant states, increasing the light absorption edge from 380 nm to 550 nm without adding mid-gap states. The dopant states are experimentally resolved in the excited state by correlating transient absorption spectroscopy with a supercontinuum probe and DFT prediction. The lack of mid-gap states is further confirmed by measuring the excited state lifetimes, which reveal the shifted band edge only increased carrier thermalization rates to the band edge and not interband charge recombination under both ultraviolet and visible excitation. Terahertz (time-domain) spectroscopy also reveals that the conduction mechanism remains unchanged after doping, suggesting the states are delocalized. PMID:26531849

  17. Social and behavioral skills and the gender gap in early educational achievement.

    PubMed

    Diprete, Thomas A; Jennings, Jennifer L

    2012-01-01

    Though many studies have suggested that social and behavioral skills play a central role in gender stratification processes, we know little about the extent to which these skills affect gender gaps in academic achievement. Analyzing data from the Early Child Longitudinal Study-Kindergarten Cohort, we demonstrate that social and behavioral skills have substantively important effects on academic outcomes from kindergarten through fifth grade. Gender differences in the acquisition of these skills, moreover, explain a considerable fraction of the gender gap in academic outcomes during early elementary school. Boys get roughly the same academic return to social and behavioral skills as their female peers, but girls begin school with more advanced social and behavioral skills and their skill advantage grows over time. While part of the effect may reflect an evaluation process that rewards students who better conform to school norms, our results imply that the acquisition of social and behavioral skills enhances learning as well. Our results call for a reconsideration of the family and school-level processes that produce gender gaps in social and behavioral skills and the advantages they confer for academic and later success. PMID:23017693

  18. 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

  19. Ultra-narrow width air-gap Si FET integrated with micro-fluidic delivery for charge based sensing

    NASA Astrophysics Data System (ADS)

    Gokirmak, Ali; Tiwari, Sandip

    2005-11-01

    An ultra-narrow width silicon field effect transistor (FET) with a suspended gate, integrated with on-chip microfluidic delivery system is described. The device is designed to be used as an FET based sensor for sequencing of DNA, RNA and proteins, by detecting the local charge variations along the chains of these molecules as they are passed between the gate and the channel of the FET in an aqueous solution. A side-gated FET structure is demonstrated with sub-10 nm width, successfully suppressing the electrical leakage currents at the device edges. Side-gated FET structure allows electrostatic confinement of the electrons in the channel for increased spatial resolution.

  20. Preparation of Narrow Band-Gap Cu2Sn(S,Se)3 and Fabrication of Film by Non-Vacuum Process

    NASA Astrophysics Data System (ADS)

    Nomura, Takeshi; Maeda, Tsuyoshi; Wada, Takahiro

    2013-04-01

    We successfully prepared a Cu2Sn(S1-xSex)3 (CTSSe) solid solution with 0≤x≤1.0. CTSSe solid solution powders were synthesized by mixing the elemental powders and post-annealing at 600 °C. The crystal structure of Cu2SnS3 (CTS) was characterized by Rietveld refinement of the powder X-ray diffraction data and determined to be a monoclinic crystal system. The band gaps of CTSSe solid solution were determined by the diffuse reflectance spectra of the powder samples and the transmittance spectrum of the film fabricated by a non-vacuum thin-film fabrication process called printing and high-pressure sintering (PHS). The band gap (Eg) of CTS is 0.87 eV, which is in good agreement with the recently reported value of monoclinic CTS film. The band gap of the Cu2Sn(S1-xSex)3 solid solution linearly decreases from 0.87 eV (x = 0.0) to 0.67 eV (x = 0.6) with increasing Se content. The CTSSe solid solution has potential as a narrow band-gap absorber material for thin-film full spectrum solar cells.

  1. Competitive behavior of photons contributing to junction voltage jump in narrow band-gap semiconductor multi-quantum-well laser diodes at lasing threshold

    NASA Astrophysics Data System (ADS)

    Feng, Liefeng; Yang, Xiufang; Li, Yang; Li, Ding; Wang, Cunda; Yao, Dongsheng; Hu, Xiaodong; Li, Hongru

    2015-04-01

    The junction behavior of different narrow band-gap multi-quantum-well (MQW) laser diodes (LDs) confirmed that the jump in the junction voltage in the threshold region is a general characteristic of narrow band-gap LDs. The relative change in the 1310 nm LD is the most obvious. To analyze this sudden voltage change, the threshold region is divided into three stages by Ithl and Ithu, as shown in Fig. 2; Ithl is the conventional threshold, and as long as the current is higher than this threshold, lasing exists and the IdV/dI-I plot drops suddenly; Ithu is the steady lasing point, at which the separation of the quasi-Fermi levels of electron and holes across the active region (Vj) is suddenly pinned. Based on the evolutionary model of dissipative structure theory, the rate equations of the photons in a single-mode LD were deduced in detail at Ithl and Ithu. The results proved that the observed behavior of stimulated emission suddenly substituting for spontaneous emission, in a manner similar to biological evolution, must lead to a sudden increase in the injection carriers in the threshold region, which then causes the sudden increase in the junction voltage in this region.

  2. Competitive behavior of photons contributing to junction voltage jump in narrow band-gap semiconductor multi-quantum-well laser diodes at lasing threshold

    SciTech Connect

    Feng, Liefeng E-mail: lihongru@nankai.edu.cn; Yang, Xiufang; Wang, Cunda; Yao, Dongsheng; Li, Yang; Li, Ding; Hu, Xiaodong; Li, Hongru E-mail: lihongru@nankai.edu.cn

    2015-04-15

    The junction behavior of different narrow band-gap multi-quantum-well (MQW) laser diodes (LDs) confirmed that the jump in the junction voltage in the threshold region is a general characteristic of narrow band-gap LDs. The relative change in the 1310 nm LD is the most obvious. To analyze this sudden voltage change, the threshold region is divided into three stages by I{sub th}{sup l} and I{sub th}{sup u}, as shown in Fig. 2; I{sub th}{sup l} is the conventional threshold, and as long as the current is higher than this threshold, lasing exists and the IdV/dI-I plot drops suddenly; I{sub th}{sup u} is the steady lasing point, at which the separation of the quasi-Fermi levels of electron and holes across the active region (V{sub j}) is suddenly pinned. Based on the evolutionary model of dissipative structure theory, the rate equations of the photons in a single-mode LD were deduced in detail at I{sub th}{sup l} and I{sub th}{sup u}. The results proved that the observed behavior of stimulated emission suddenly substituting for spontaneous emission, in a manner similar to biological evolution, must lead to a sudden increase in the injection carriers in the threshold region, which then causes the sudden increase in the junction voltage in this region.

  3. Minding the Gaps in Continuous Glucose Monitoring: A Method to Repair Gaps to Achieve More Accurate Glucometrics

    PubMed Central

    Fonda, Stephanie J.; Lewis, Drew G.; Vigersky, Robert A.

    2013-01-01

    Estimation of glycemic variability requires frequent measures of glucose and is greatly aided by continuous glucose monitoring (CGM); however, under real-world conditions, missing data or “gaps” of ≥ 10 minutes can occur in CGM data, affecting the reliability of certain estimates. Thus, we determined the magnitude of the gap problem as observed in a cohort of patients with type 2 diabetes and demonstrated an approach to fill the gaps. The approach takes the difference between readings before and after a gap and distributes the difference equally across the number of missing readings, as determined by the sensor’s setting for reading frequency. The approach is easy to implement, conservative, and improves estimation of variability measures that reference time, namely, mean of daily differences and continuous overlapping net glycemic action. PMID:23439163

  4. The Education of English Language Learners in Arizona: A Legacy of Persisting Achievement Gaps in a Restrictive Language Policy Climate

    ERIC Educational Resources Information Center

    Garcia, Eugene E.; Lawton, Kerry; Diniz de Figueiredo, Eduardo H.

    2010-01-01

    This report reviews achievement gaps in both reading and math between ELL and non-ELL students in Arizona over the post-Proposition 203 period 2005-2009 and during the first year of implementation of the 4 hour ELD block, 2008-09. The study finds that Arizona has made little to no progress in closing the achievement gap between ELL and non-ELL…

  5. A Capstone Project: Closing the Achievement Gap of English Language Learners at Sunshine Elementary School Using the Gap Analysis Model

    ERIC Educational Resources Information Center

    Mingo-Long, Enyetta

    2013-01-01

    This project was an alternative capstone dissertation conducted by a team of three doctoral students. The project focused on systematic and long-term underachievement of the English Language Learner (ELL) population of a single school, Sunshine Elementary, using the gap analysis model (Clark and Estes, 2008). More specifically, the purpose of the…

  6. Configuration dependence of band-gap narrowing and localization in dilute GaAs1 -xBix alloys

    NASA Astrophysics Data System (ADS)

    Bannow, Lars C.; Rubel, Oleg; Badescu, Stefan C.; Rosenow, Phil; Hader, Jörg; Moloney, Jerome V.; Tonner, Ralf; Koch, Stephan W.

    2016-05-01

    Anion substitution with bismuth (Bi) in III-V semiconductors is an effective method for experimental engineering of the band gap Eg at low Bi concentrations (≤2 % ), in particular in gallium arsenide (GaAs). The inverse Bi-concentration dependence of Eg has been found to be linear at low concentrations x and dominated by a valence band defect level anticrossing between As and Bi occupied p levels. Predictive models for the valence band hybridization require a first-principle understanding which can be obtained by density functional theory with the main challenges being the proper description of Eg and the spin-orbit coupling. By using an efficient method to include these effects, it is shown here that at high concentrations Eg is modified mainly by a Bi-Bi p orbital interaction and by the large Bi atom-induced strain. In particular, we find that at high concentrations, the Bi-Bi interactions depend strongly on model periodic cluster configurations, which are not captured by tight-binding models. Averaging over various configurations supports the defect level broadening picture. This points to the role of different atomic configurations obtained by varying the experimental growth conditions in engineering arsenide band gaps, in particular for telecommunication laser technology.

  7. Time resolved photoluminescence spectroscopy of narrow gap Hg{sub 1−x}Cd{sub x}Te/Cd{sub y}Hg{sub 1−y}Te quantum well heterostructures

    SciTech Connect

    Morozov, S. V.; Rumyantsev, V. V. Antonov, A. V.; Kadykov, A. M.; Maremyanin, K. V.; Kudryavtsev, K. E.; Gavrilenko, V. I.; Mikhailov, N. N.; Dvoretskii, S. A.

    2014-07-14

    Photoluminescence (PL) spectra and kinetics of narrow gap Hg{sub 1−x}Cd{sub x}Te/Cd{sub y}Hg{sub 1−y}Te quantum well (QW) heterostructures grown by molecular beam epitaxy technique are studied. Interband PL spectra are observed from 18 K up to the room temperature. Time resolved studies reveal an additional PL line with slow kinetics (7 μs at 18 K) related to deep defect states in barrier layers. These states act as traps counteracting carrier injection into QWs. The decay time of PL signal from QW layers is about 5 μs showing that gain can be achieved at wavelengths 10–20 μm by placing such QWs in HgCdTe structures with waveguides.

  8. Narrowing the Achievement Gap: Strategies for Educating Latino, Black, and Asian Students. The Claremont Letter. Volume 2, Issue 1

    ERIC Educational Resources Information Center

    Paik, Susan J.

    2006-01-01

    In November of 2005, researchers, practitioners, and policymakers gathered at a national invitational conference in Washington, D.C. sponsored by the Laboratory for Student Success. The event took place just blocks away from the Capitol Rotunda where, days before, Rosa Parks' body laid in state as the nation mourned her passing. The conference…

  9. Educational Achievement Gaps between Immigrant and Native Students in Two “New Immigration Countries”: Italy and Spain in comparison

    PubMed Central

    Azzolini, Davide; Schnell, Philipp; Palmer, John

    2013-01-01

    We use PISA 2009 data to determine how immigrant children in Italy and Spain compare with native students in reading and mathematics skills. Drawing on the vast empirical literature in traditional immigration countries, we test the extent to which the most well-established patterns and hypotheses of immigrant/native educational achievement gaps also apply to these new immigration countries. Findings show that both first- and second-generation immigrant students underperform natives in both countries. Although socioeconomic background and language skills contribute to the explanation of achievement gaps, significant differences remain within countries. While modeling socioeconomic background reduces the observed gaps to a very similar extent in the two countries, language spoken at home is more strongly associated with achievement in Italy. School-type differentiation, such as tracking in Italy and school ownership in Spain, do not reduce immigrant/native gaps, although in Italy tracking is strongly associated with students’ test scores. PMID:23493944

  10. Assertive Outreach Strategies for Narrowing the Adolescent Substance Abuse Treatment Gap: Implications for Research, Practice, and Policy

    PubMed Central

    Ozechowski, Timothy J.; Waldron, Holly Barrett

    2009-01-01

    In any given year, only about 10% of the nearly two million adolescents exhibiting substance abuse or dependence in the United States receive substance abuse treatment. Given this state of affairs, it is unlikely that the massive effort and expenditure of resources over the past decade on developing, testing, and disseminating effective treatments for adolescent substance abuse can have an appreciable impact on the prevalence of substance use disorders among the adolescent population. In order to substantially diminish the pervasive gap between levels of need for and utilization of adolescent substance abuse treatment, specialized assertive outreach strategies may be needed. This paper outlines a framework for assertive outreach for adolescents with substance use disorders, and proposes specific types of strategies for identifying and enrolling such adolescents into treatment. Implications for practice and policy pertaining to adolescent substance abuse treatment service delivery are considered. PMID:18690540

  11. Gender gaps in achievement and participation in multiple introductory biology classrooms.

    PubMed

    Eddy, Sarah L; Brownell, Sara E; Wenderoth, Mary Pat

    2014-01-01

    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel. PMID:25185231

  12. Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms

    PubMed Central

    Brownell, Sara E.; Wenderoth, Mary Pat

    2014-01-01

    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel. PMID:25185231

  13. Reassessing a Learning Gap: A Comparative Study of Student Science Achievement in the U.S. and China.

    ERIC Educational Resources Information Center

    Wang, Jianjun

    1996-01-01

    Reviews current literature related to the science achievement "learning gap" between Chinese and U.S. students. Presents an empirical assessment based on a more representative database from both countries. An extended mid-1980s study (the Second International Association for the Evaluation of Educational Achievement Study, or SSIS), found no…

  14. On the Intractability of the Achievement Gap in Urban Schools and the Discursive Practice of Continuing Racial Discrimination.

    ERIC Educational Resources Information Center

    English, Fenwick W.

    2002-01-01

    Achievement gaps between minority and white students may never be resolved because they are an artifact of a measurement process that uses flawed tests to assess student progress. IQ and achievement testing have always shown that socioeconomic status (SES) is critical in explaining test score variance. SES is part of the concept of cultural…

  15. An Examination of Tri-Level Collaboration around Student Achievement Using the Gap Analysis Approach: Central Office Leadership Factors

    ERIC Educational Resources Information Center

    Llamas, Sonia Rodarte

    2013-01-01

    Using the Gap Analysis problem-solving framework (Clark & Estes, 2008), this study examined collaboration around student achievement at the central office leadership level in the Pasadena Unified School District (PUSD). This study is one of three concurrent studies focused on collaboration around student achievement in the PUSD that include…

  16. Closing the Achievement Gap Report for 21st Century Learners in West Virginia. Third Edition, 2009-2010

    ERIC Educational Resources Information Center

    Smith, Diana L., Ed.

    2009-01-01

    The goal of the "Closing the Achievement Gap for 21st Century Learners in West Virginia (CAG)" report, 3rd edition, is to update West Virginia educators to the status and improvement of student achievement in West Virginia which may then be utilized as a basis for determining future educational decisions. In order to enhance the quality of…

  17. An Examination of Tri-Level Collaboration around Student Achievement Using the Gap Analysis Approach: School Site Leadership Factors

    ERIC Educational Resources Information Center

    Salinas, Esther Charlotte

    2013-01-01

    Using the Gap Analysis problem-solving framework (Clark & Estes, 2008), this project examined collaboration around student achievement at the school site leadership level in the Pasadena Unified School District (PUSD). This project is one of three concurrent studies focused on collaboration around student achievement in the PUSD that include…

  18. Ethnicity, Gender, Social Class and Achievement Gaps at Age 16: Intersectionality and "Getting It" for the White Working Class

    ERIC Educational Resources Information Center

    Strand, Steve

    2014-01-01

    Perhaps the most prevailing inequalities in educational achievement in England are those associated with socio-economic status (SES), ethnicity and gender. However, little research has sought to compare the relative size of these gaps or to explore interactions between these factors. This paper analyses the educational achievement at age 11, 14…

  19. Closing the gap in academic readiness and achievement: the role of early childcare

    PubMed Central

    Geoffroy, Marie-Claude; Côté, Sylvana. M.; Giguère, Charles-Édouard; Dionne, Ginette; Zelazo, Philip David; Tremblay, Richard E.; Boivin, Michel; Séguin, Jean. R.

    2012-01-01

    Background Socially disadvantaged children with academic difficulties at school entry are at increased risk for poor health and psychosocial outcomes. Our objective is to test the possibility that participation in childcare – at the population level – could attenuate the gap in academic readiness and achievement between children with and without a social disadvantage (indexed by low levels of maternal education). Methods A cohort of infants born in the Canadian province of Quebec in 1997/1998 was selected through birth registries and followed annually until 7 years of age (n = 1,863). Children receiving formal childcare (i.e., center-based or non-relative out-of-home) were distinguished from those receiving informal childcare (i.e., relative or nanny). Measures from 4 standardized tests that assessed cognitive school readiness (Lollipop Test for School Readiness), receptive vocabulary (Peabody Picture Vocabulary Test Revised), mathematics (Number Knowledge Test), and reading performance (Kaufman Assessment Battery for children) were administered at 6 and 7 years. Results Children of mothers with low levels of education showed a consistent pattern of lower scores on academic readiness and achievement tests at 6 and 7 years than those of highly educated mothers, unless they received formal childcare. Specifically, among children of mothers with low levels of education, those who received formal childcare obtained higher school readiness (d = 0.87), receptive vocabulary (d = 0.36), reading (d = 0.48) and math achievement scores (d = 0.38; although not significant at 5%) in comparison with those who were cared for by their parents. Childcare participation was not associated with cognitive outcomes among children of mothers with higher levels of education. Conclusions Public investments in early childcare are increasing in many countries with the intention of reducing cognitive inequalities between disadvantaged and advantaged children. Our findings provide further

  20. Side-chain effects on the conductivity, morphology, and thermoelectric properties of self-doped narrow-band-gap conjugated polyelectrolytes.

    PubMed

    Mai, Cheng-Kang; Schlitz, Ruth A; Su, Gregory M; Spitzer, Daniel; Wang, Xiaojia; Fronk, Stephanie L; Cahill, David G; Chabinyc, Michael L; Bazan, Guillermo C

    2014-10-01

    This contribution reports a series of anionic narrow-band-gap self-doped conjugated polyelectrolytes (CPEs) with π-conjugated cyclopenta-[2,1-b;3,4-b']-dithiophene-alt-4,7-(2,1,3-benzothiadiazole) backbones, but with different counterions (Na(+), K(+), vs tetrabutylammonium) and lengths of alkyl chains (C4 vs C3). These materials were doped to provide air-stable, water-soluble conductive materials. Solid-state electrical conductivity, thermopower, and thermal conductivity were measured and compared. CPEs with smaller counterions and shorter side chains exhibit higher doping levels and form more ordered films. The smallest countercation (Na(+)) provides thin films with higher electrical conductivity, but a comparable thermopower, compared to those with larger counterions, thereby leading to a higher power factor. Chemical modifications of the pendant side chains do not influence out of plane thermal conductivity. These studies introduce a novel approach to understand thermoelectric performance by structural modifications. PMID:25179403

  1. Structural and thermal properties of ternary narrow-gap oxide semiconductor; wurtzite-derived β-CuGaO2.

    PubMed

    Nagatani, Hiraku; Suzuki, Issei; Kita, Masao; Tanaka, Masahiko; Katsuya, Yoshio; Sakata, Osami; Miyoshi, Shogo; Yamaguchi, Shu; Omata, Takahisa

    2015-02-16

    The crystal structure of the wurtzite-derived β-CuGaO2 was refined by Rietveld analysis of high-resolution powder diffraction data obtained from synchrotron X-ray radiation. Its structural characteristics are discussed in comparison with the other I-III-VI2 and II-VI oxide semiconductors. The cation and oxygen tetrahedral distortions of the β-CuGaO2 from an ideal wurtzite structure are small. The direct band-gap nature of the β-CuGaO2, unlike β-Ag(Ga,Al)O2, was explained by small cation and oxygen tetrahedral distortions. In terms of the thermal stability, the β-CuGaO2 irreversibly transforms into delafossite α-CuGaO2 at >460 °C in an Ar atmosphere. The transformation enthalpy was approximately -32 kJ mol(-1), from differential scanning calorimetry. This value is close to the transformation enthalpy of CoO from the metastable zincblende form to the stable rock-salt form. The monovalent copper in β-CuGaO2 was oxidized to divalent copper in an oxygen atmosphere and transformed into a mixture of CuGa2O4 spinel and CuO at temperatures >350 °C. These thermal properties indicate that β-CuGaO2 is stable at ≤300 °C in both reducing and oxidizing atmospheres while in its metastable form. Consequently, this material could be of use in optoelectronic devices that do not exceed 300 °C. PMID:25651414

  2. Birth Cohort and the Black-White Achievement Gap: The Roles of Access and Health Soon After Birth. WP2008-20

    ERIC Educational Resources Information Center

    Chay, Kenneth Y.; Guryan, Jonathan; Mazumder, Bhashkar

    2009-01-01

    One literature documents a significant, black-white gap in average test scores, while another finds a substantial narrowing of the gap during the 1980's, and stagnation in convergence after. We use two data sources--the Long Term Trends NAEP and AFQT scores for the universe of applicants to the U.S. military between 1976 and 1991--to show: (1) the…

  3. Electronic Characterization of Defects in Narrow Gap Semiconductors-Comparison of Electronic Energy Levels and Formation Energies in Mercury Cadmium Telluride, Mercury Zinc Telluride, and Mercury Zinc Selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1996-01-01

    We have used a Green's function technique to calculate the energy levels and formation energy of deep defects in the narrow gap semiconductors mercury cadmium telluride (MCT), mercury zinc telluride (MZT) and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total energy with an impurity cluster and the total energy for the perfect crystal. Substitutional (including antisite), interstitial (self and foreign), and vacancy deep defects are considered. Relaxation effects are calculated (with molecular dynamics). By use of a pseudopotential, we generalize the ideal vacancy model so as to be able to consider relaxation for vacancies. Different charge states are considered and the charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that due to relaxation. Different charged states for vacancies were not calculated to have much effect on the formation energy. For all cases we find deep defects in the energy gap only for cation site s-like orbitals or anion site p-like orbitals, and for the substitutional case only the latter are appreciably effected by relaxation. For most cases for MCT, MZT, MZS, we consider x (the concentration of Cd or Zn) in the range appropriate for a band gap of 0.1 eV. For defect energy levels, the absolute accuracy of our results is limited, but the precision is good, and hence chemical trends are accurately predicted. For the same reason, defect formation energies are more accurately predicted than energy level position. We attempt, in Appendix B, to calculate vacancy formation energies using relatively simple chemical bonding ideas due to Harrison. However, these results are only marginally accurate for estimating vacancy binding energies. Appendix C lists all written reports and publications produced for the grant. We include abstracts and a complete paper that summarizes our work which is not yet available.

  4. Probing Spin and Spin-Orbit Coupling effects in Narrow-gap Semiconductor Nano-structures by THz Magneto-photoresponse Spectroscopy and Magneto-transport Measurements

    NASA Astrophysics Data System (ADS)

    Pakmehr, Mehdi

    Using the spin degree of freedom in a emergent field Known as Spintronics has motivated scientist in different disciplines including physicist within last 10 years. Due to different interaction mechanisms which affects the physical behavior of spin (eg its state and transport properties) within solid medium (Semiconductors in our case), one needs to distinguish these mechanisms and their importance for making any practical spin based devices. For example the idea of making spin based transistors with electrons being transported within InGaAs and their spin state is being controlled by Rashba type field has been around for around 25 years but injection of spin polarized currents from a source into the channel has not been solved yet. Spin orbit coupling (SOC) is one of the mechanisms which changes the spin state of electrons and avoid the existence of pure spin state as a favorable one from device point of view. SOC could have a different origin depending on material type or structure of device. One method of measuring and quantifying this mechanisms within semiconductor nanostructures is through measuring the parameters known as Lande g-factor. This parameters turns out to be a promising one to probe different effects on electronic band structure including quantum confinement, strain, electric filed, etc. We probe a combination of these effects (SOC, Strain, band mixing, etc) by measuring different g-factor tensor components of narrow gap Zinc blend semiconductor nanostructures which we hope finally serve to the purpose of making reliable spin based devices* (Spintronics). To reach this goal we have developed and implemented THz magneto-Photoresponse spectroscopy in conjunction with magneto-transport measurements at cryogenic temperatures. The samples include InAs and HgTe based Quantum wells as well as InAs based quantum point contact. Our findings clarify the situation where the combination of SOC, Strain, quantum confinements as well as many body electron effect

  5. 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…

  6. Patterns and Trends in Achievement Gaps in Malaysian Secondary Schools (1999-2011): Gender, Ethnicity, and Socioeconomic Status

    ERIC Educational Resources Information Center

    Saw, Guan Kung

    2016-01-01

    Educational inequality is a highly debated yet empirically understudied topic in Malaysia. This paper examines the patterns and trends of academic achievement gaps by student social groups in Malaysia, drawing upon nationally representative data for the most recent four cohorts (1999, 2003, 2007, and 2011) of eighth-grade Malaysian students from…

  7. No More Profiling in the Classroom: A Midsize Urban School District's Efforts to Close the Achievement Gap

    ERIC Educational Resources Information Center

    Smith-Evans, Leticia Victoria

    2010-01-01

    For approximately a third of this decade, a mid-size urban school district took a bold step in its continuing efforts to battle what has been a persistent problem plaguing this Nation's education system for decades or possibly for as long as it has existed--the achievement gap between students of color and their White peers. The district has…

  8. Class and Schools: Using Social, Economic, and Educational Reform to Close The Black?White Achievement Gap

    ERIC Educational Resources Information Center

    Taylor, Dianne L.

    2005-01-01

    This paper presents a comprehensive review of Richard Rothstein's book "Class and Schools: Using Social, Economic, and Educational Reform to Close the Black-White Achievement Gap" (Washington, DC: Economic Policy Institute, 2004). The insights offered in this book are timely in light of the No Child Left Behind legislation that puts the force of…

  9. 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…

  10. The School Age Gender Gap in Reading Achievement: Examining the Influences of Item Format and Intrinsic Reading Motivation

    ERIC Educational Resources Information Center

    Schwabe, Franziska; McElvany, Nele; Trendtel, Matthias

    2015-01-01

    The importance of reading competence for both individuals and society underlines the strong need to understand the gender gap in reading achievement. Beyond mean differences in reading comprehension, research has indicated that girls possess specific advantages on constructed-response items compared with boys of the same reading ability. Moreover,…

  11. Black-White Achievement Gap and Family Wealth. National Poverty Center Working Paper Series #07-02

    ERIC Educational Resources Information Center

    Yeung, W. Jean; Conley, Dalton

    2006-01-01

    This paper examines the extent to which family wealth affects the race-child achievement association for young children based on data from the Panel Study of Income Dynamics. We found little evidence that wealth mediates the black-white test scores gap. However, liquid assets, particularly holding in stocks and mutual funds, are positively…

  12. Science Instructional Time Is Declining in Elementary Schools: What Are the Implications for Student Achievement and Closing the Gap?

    ERIC Educational Resources Information Center

    Blank, Rolf K.

    2013-01-01

    Recent comparative data on high school graduates show that many American students are not well prepared in fields of science, technology, engineering, and mathematics and that there is a persistent achievement gap according to the socioeconomic backgrounds of students. The research for this paper focuses on the role of elementary education in…

  13. Closing the Student Achievement Gap in California's Elementary Schools: A Lead Teachers' Perspective on Transformational Instructional Leadership

    ERIC Educational Resources Information Center

    Hays, Kelli

    2010-01-01

    This study has tackled the thorny problem of closing the Student Achievement Gap (SAG) in California's elementary schools. To address that problem, an "Integrated" form of educational leadership called Transformational Instructional Leadership (TIL), a form grounded in "best practices" of Transformational and Instructional leadership, was…

  14. Science Achievement Gaps by Gender and Race/Ethnicity in Elementary and Middle School: Trends and Predictors

    ERIC Educational Resources Information Center

    Quinn, David M.; Cooc, North

    2015-01-01

    Research on science achievement disparities by gender and race/ethnicity often neglects the beginning of the pipeline in the early grades. We address this limitation using nationally representative data following students from Grades 3 to 8. We find that the Black-White science test score gap (-1.07 SD in Grade 3) remains stable over these years,…

  15. Addressing Achievement Gaps: The Family--America's Smallest School. Policy Notes. Volume 19, Number 1, Winter 2011

    ERIC Educational Resources Information Center

    Yaffe, Deborah

    2011-01-01

    When parents are married and employed, when they turn off the television and monitor homework, their children are more likely to succeed in school. Today, however, many families are struggling, and their struggles contribute to the stubborn achievement gap separating low-income and minority students from their more affluent White and Asian peers.…

  16. Closing the Academic Achievement Gap on the California High School Exit Exam (CAHSEE) through Professional Learning Communities (PLC) Characteristics

    ERIC Educational Resources Information Center

    Buenrostro, Samuel

    2012-01-01

    Purpose: The purpose of this study was to determine the degree of importance that DuFour's nine characteristics of highly effective schools have on closing the academic achievement gap on the California High School Exit Exam, as perceived by high school principals. The study also examined the strategies believed to be most important in…

  17. Drivers of Success: One District's Process for Closing Achievement Gaps in a Post-No Child Left Behind Context

    ERIC Educational Resources Information Center

    O'Doherty, Ann; Ovando, Martha N.

    2009-01-01

    In this original qualitative study, we examined the processes employed by a school district that had made progress in closing achievement gaps in a post-No Child Left Behind context. The district served more than 26,000 students in an economically and ethnically diverse community. Secondary analysis of the findings uncovered a primary…

  18. Religiosity, Religious Schools, and Their Relationship with the Achievement Gap: A Research Synthesis and Meta-Analysis

    ERIC Educational Resources Information Center

    Jeynes, William H.

    2010-01-01

    A research synthesis was conducted including three meta analyses, a review of the relevant literature, and supplemental analyses examining the relationship between personal faith and the reduction of the achievement gap. Personal faith included belief and adherence to any religion. The results of the three meta-analyses indicated that: (a)…

  19. Understanding and Addressing the California Latino Achievement Gap in Early Elementary School. Working Paper 2004-01

    ERIC Educational Resources Information Center

    Rumberger, Russell W.; Anguiano, Brenda Arellano

    2004-01-01

    One of the most pressing problems in California is improving student academic performance, especially the state's burgeoning Latino student population. This study examined the extent of the achievement gap between Latino and White students over the first two years of elementary school and the characteristics of students and schools that contribute…

  20. An Investigation of No Child Left Behind and Its Primary Purpose to Close the Achievement Gap

    ERIC Educational Resources Information Center

    Holmes, Shaun L.

    2012-01-01

    Research has suggested the 2001 No Child Left Behind high-stakes testing legislation has resulted in a narrowed curriculum, decreased opportunities for poor and minority students, and decreased job satisfaction among teachers and administrators. Given the considerably negative influence No Child Left Behind legislation has had on public education,…

  1. Temperature dependence of the carrier lifetime in narrow-gap Cd{sub x}Hg{sub 1–x}Te solid solutions: Radiative recombination

    SciTech Connect

    Bazhenov, N. L. Mynbaev, K. D.; Zegrya, G. G.

    2015-09-15

    The probability of the radiative recombination of carriers in narrow-gap semiconductors is analyzed for the example of Cd{sub x}Hg{sub 1–x}Te solid solutions. Expressions are derived for the imaginary part of the dielectric permittivity in terms of the three-band Kane’s model with consideration for the nonparabolic dependence of the carrier energy on the wave vector. It is shown that taking into account this nonparabolicity of the energy spectrum of carriers modifies the dependence of the imaginary part of the dielectric permittivity on frequency. Expressions for the probability of radiative recombination, derived in terms of the simple parabolic model and Kane’s model with and without the nonparabolicity effect taken into account, are compared. It is shown that the contributions to recombination from electron transitions to heavy- and light-hole bands are close and the contribution from light holes cannot be neglected when calculating the radiative-recombination probability.

  2. Specific features of the spectra and relaxation kinetics of long-wavelength photoconductivity in narrow-gap HgCdTe epitaxial films and heterostructures with quantum wells

    SciTech Connect

    Rumyantsev, V. V. Ikonnikov, A. V.; Antonov, A. V.; Morozov, S. V.; Zholudev, M. S.; Spirin, K. E.; Gavrilenko, V. I.; Dvoretskii, S. A.; Mikhailov, N. N.

    2013-11-15

    The spectra and relaxation kinetics of interband photoconductivity are investigated in narrow-gap Hg{sub 1-x}Cd{sub x}Te epitaxial films with x = 0.19-0.23 and in structures with HgCdTe-based quantum wells (QWs), having an interband-transition energy in the range of 30-90 meV, grown by molecular-beam epitaxy on GaAs (013) substrates. A long-wavelength sensitivity band caused by impurities or defects is found in the spectra of the structures with quantum wells in addition to the interband photoconductivity. It is shown that the lifetimes of nonequilibrium carriers in the structures with QWs is less than in bulk samples at the same optical-transition energy. From the measured carrier lifetimes, the ampere-watt responsivity and the equivalent noise power for a film with x = 0.19 at a wavelength of 19 {mu}m are estimated. When investigating the relaxation kinetics of the photoconductivity at 4.2 K in high excitation regime, it is revealed that radiative recombination is dominant over other mechanisms of nonequilibrium-carrier recombination.

  3. Nursing Students Achieving Community Health Competencies through Undergraduate Clinical Experiences: A Gap Analysis.

    PubMed

    Pijl-Zieber, Em M; Barton, Sylvia; Awosoga, Oluwagbohunmi A; Konkin, Jill

    2015-01-01

    In Canada, it is widely believed that nursing practice and health care will move from acute care into the community. At the same time, increasing numbers of nursing students are engaged in non-traditional clinical experiences for their community health rotation. These clinical experiences occur at agencies not organizationally affiliated with the health care system and typically do not employ registered nurses (RNs). What has yet to be established is the degree to which nursing students are actually being prepared for community health nursing roles through their community health clinical rotations. In this paper we report the findings of a mixed method study that explored the gap between desired and observed levels of competence in community health of senior nursing students and new graduates. The gap was quantified and then the nature of the gap further explored through focus groups. PMID:26461843

  4. 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…

  5. Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms

    ERIC Educational Resources Information Center

    Eddy, Sarah L.; Brownell, Sara E.; Wenderoth, Mary Pat

    2014-01-01

    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large…

  6. Administrator Perceptions of the Achievement Gap between African American Students and Other Subpopulations

    ERIC Educational Resources Information Center

    Royle, Jonathan

    2013-01-01

    The consistent underperformance of African American students casts a disparaging shadow on the success of American public schools. Research was necessary to understand the reason for such a difference in scores. Parents, teachers, and administrators must understand the reason for the gap in order to determine the strategies and support systems…

  7. Gauging the Gaps: A Deeper Look at Student Achievement. K-12 Policy

    ERIC Educational Resources Information Center

    Rowan, Anna Habash; Hall, Daria; Haycock, Kati

    2010-01-01

    Leaders in schools, districts, and states, along with policymakers in Washington, D.C., are focusing new energy on closing long-standing gaps in performance that separate low-income students and students of color from others. It's critically important that their efforts succeed--for students, their families, their communities, and for their…

  8. Explaining the Gap: Teacher Efficacy and the Conceptualization of Minority Student Achievement

    ERIC Educational Resources Information Center

    Wilmore, Christian

    2009-01-01

    The No Child Left Behind legislation has drawn a great deal of attention to the gap' that exists between the academic performance of Black and Hispanic students as compared to their White counterparts. While numerous reform efforts have been implemented to address this disparity, to date little research has been done to connect a teacher's sense…

  9. Social Welfare and Minding the Achievement Gap: A View from Denmark

    ERIC Educational Resources Information Center

    Ringsmose, Charlotte

    2012-01-01

    In Denmark, the welfare system has evened out the gaps between rich and poor. Schools and child care settings all over the country have an equal level of resources provided by the state, and are financed through taxes. Schools and child care settings in areas with families of lower socioeconomic status (SES) get extra money and resources. All…

  10. The Black Gender Achievement Gap: A Historical Perspective. The Claremont Letter. Volume 4, Issue 2

    ERIC Educational Resources Information Center

    Perkins, Linda M.

    2010-01-01

    Recent studies have discussed the growing gap of college attendance and graduation rates of women and girls. While the rate of White women's college attendance and graduation now surpasses that of men, this has been the case for Black women for over a century. Throughout the twentieth century until the present, Black women have earned more college…

  11. The Shrinking Black-White Gap on SAT II Achievement Tests.

    ERIC Educational Resources Information Center

    Journal of Blacks in Higher Education, 2002

    2002-01-01

    Recent research shows that the SAT II test is a much better predictor of college success than the standard SAT. In recent years, black students appear to be making progress in closing the racial scoring gap on the wide variety of academic subjects (particularly chemistry, world history, and biology) that are measured by the SAT II test. (SM)

  12. Cultivating the Genius of Black Children: Strategies to Close the Achievement Gap in the Early Years

    ERIC Educational Resources Information Center

    Sullivan, Debra Ren-Etta

    2016-01-01

    There has been much attention given to the opportunity gap between white and minority students, especially African American children. Using research and years of experience "Cultivating the Genius of Black Children" is able to break down the cultural influences on learning style and provides a practical approach to helping Black children…

  13. Dollars for Sense: Assessing Achievement Gaps in Arkansas in the Context of Substantial Funding Increases

    ERIC Educational Resources Information Center

    Barnett, Joshua; Jensen, Nathan C.; Ritter, Gary W.

    2010-01-01

    Forty-four of the fifty states have experienced school finance lawsuits as a consequence of funding gaps between rich and poor districts. In some states, such as Kentucky, lawsuits brought about by property-poor districts have resulted in a statewide remedy that reforms the property tax system and seeks to provide every child with an adequate…

  14. An Effort to Close Achievement Gaps at Scale through Self-Affirmation

    ERIC Educational Resources Information Center

    Borman, Geoffrey D.; Grigg, Jeffrey

    2013-01-01

    This study addresses closing the academic performance gaps between African American and Latino students and their White counterparts, and between girls and boys in mathematics. Of the various models and theories of these social inequalities that have been advanced in literature, one particularly compelling line of research concerns the idea of…

  15. Huge operation by energy gap of novel narrow band gap Tl1-x In1-x B x Se2 (B = Si, Ge): DFT, x-ray emission and photoconductivity studies

    NASA Astrophysics Data System (ADS)

    Piasecki, M.; Myronchuk, G. L.; Zamurueva, O. V.; Khyzhun, O. Y.; Parasyuk, O. V.; Fedorchuk, A. O.; Albassam, A.; El-Naggar, A. M.; Kityk, I. V.

    2016-02-01

    It is shown that narrow band gap semiconductors Tl1-x In1-x GexSe2 are able effectively to vary the values of the energy gap. DFT simulations of the principal bands during the cationic substitutions is done. Changes of carrier transport features is explored. Relation with the changes of the near the surface states is explored . Comparison on a common energy scale of the x-ray emission Se Kβ 2 bands, representing energy distribution of the Se 4p states, indicates that these states contribute preliminary to the top of the valence band. The temperature dependence of electrical conductivity and spectral dependence photoconductivity for the Tl1-x In1-x Ge x Se2 and Tl1-x In1-x Si x Se2 single crystals were explored and compared with previously reported Tl1-x In1-x Sn x Se2. Based on our investigations, a model of centre re-charging is proposed. Contrary to other investigated crystals in Tl1-x In1-x Ge x Se2 single crystals for x = 0.1 we observe extraordinarily enormous photoresponse, which exceed more than nine times the dark current. X-ray photoelectron core-level and valence-band spectra for pristine and Ar+-ion irradiated surfaces of Tl1-x In1-x GexSe2 (x = 0.1 and 0.2) single crystals have been studied. These results indicate that the relatively low hygroscopicity of the studied single crystals is typical for the Tl1-x In1-x Ge x Se2 crystals, a property that is very important for handling these quaternary selenides as infrared materials operating at ambient conditions.

  16. The Economic Benefits of Closing Educational Achievement Gaps: Promoting Growth and Strengthening the Nation by Improving the Educational Outcomes of Children of Color

    ERIC Educational Resources Information Center

    Lynch, Robert G.; Oakford, Patrick

    2014-01-01

    Our nation is currently experiencing growing levels of income and wealth inequality, which are contributing to longstanding racial and ethnic gaps in education outcomes and other areas. This report quantifies the economic benefits of closing one of the most harmful racial and ethnic gaps: the educational achievement gap that exists between black…

  17. The Gender Confidence Gap in Fractions Knowledge: Gender Differences in Student Belief-Achievement Relationships

    ERIC Educational Resources Information Center

    Ross, John A.; Scott, Garth; Bruce, Catherine D.

    2012-01-01

    Recent research demonstrates that in many countries gender differences in mathematics achievement have virtually disappeared. Expectancy-value theory and social cognition theory both predict that if gender differences in achievement have declined there should be a similar decline in gender differences in self-beliefs. Extant literature is…

  18. D.C.'s Achievement Gap: Why Place Matters. Data Snapshot

    ERIC Educational Resources Information Center

    DC Action for Children, 2012

    2012-01-01

    Every child deserves educational opportunity and the chance to achieve, no matter his or her school, neighborhood or background. Unfortunately, large and persistent disparities in achievement among public school students in the District of Columbia indicate that all children here may not have the same opportunities. This Data Snapshot examines…

  19. The Dutch Gender Gap in Mathematics: Small for Achievement, Substantial for Beliefs and Attitudes

    ERIC Educational Resources Information Center

    Meelissen, Martina; Luyten, Hans

    2008-01-01

    In general, studies on gender and mathematics show that the advantage held by boys over girls in mathematics achievement has diminished markedly over the last 40 years. Some researchers even argue that gender differences in mathematics achievement are no longer a relevant issue. However, the results of the Trends in Mathematics and Science Study…

  20. Examination of Achievement Gaps among Fourth Grade Students in a Selected Louisiana School District

    ERIC Educational Resources Information Center

    LeJeune, Kevin Scott

    2010-01-01

    A major concern for educators is that student achievement is disproportionate and not increasing for all groups at the same rate. This applied dissertation addressed the problem of unequal achievement for African American, economically disadvantaged, and academically at-risk students. This quantitative study utilized a correlational design to…

  1. Explaining the Achievement Gap between Indigenous and Non-Indigenous Students: An Analysis of PISA 2009 Results for Australia and New Zealand

    ERIC Educational Resources Information Center

    Song, Steve; Perry, Laura B.; McConney, Andrew

    2014-01-01

    This study investigates the relative roles of home and school variables in accounting for achievement gaps between Indigenous and non-Indigenous students in Australia and New Zealand. Using data from the Programme for International Student Assessment [PISA] 2009, our findings show that achievement gaps between Indigenous and non-Indigenous…

  2. Investigating the Achievement Gap between White and Minority Students in Texas: Should We Be Concerned about a Ceiling Effect on the TAAS?

    ERIC Educational Resources Information Center

    Linton, Thomas H.; Kester, Donald; Cassidy, Jack

    The purpose of this study was to investigate the achievement gap between minority and white students by analyzing 1996 and 2000 reading and mathematics scores on the Texas Assessment of Academic Skills (TAAS) at grades 5, 8, and 10. The focus was on score increases, the achievement gap between white and minority students, and whether or not a…

  3. Classroom-Based Inequalities and Achievement Gaps in First Grade: The Role of Classroom Context and Access to Qualified and Effective Teachers

    ERIC Educational Resources Information Center

    Palardy, Gregory J.

    2015-01-01

    Background: An enduring question about achievement gaps is, which aspects of schools contribute most? At the early grade levels, when children spend the vast majority of their school day in a single classroom with a single teacher, school inequities that correlate with achievement gaps likely originate within the classroom. This study examined the…

  4. No Student Left Behind: A Collaborative and Competitive Game-Based Learning Environment to Reduce the Achievement Gap of EFL Students in Taiwan

    ERIC Educational Resources Information Center

    Hung, Hui-Chun; Young, Shelley Shwu-Ching; Lin, Chiu-Pin

    2015-01-01

    How to close the achievement gap in the classroom so that no student is left behind becomes one of the most important issues nowadays. This study aims to construct a collaborative and competitive game-based learning environment to improve English proficiencies and reduce the achievement gap for disadvantaged students. The Wireless Crossword…

  5. What Is the Nature of the Achievement Gap, Why Does It Persist and Are Government Goals Sufficient to Create Social Justice in the Education System?

    ERIC Educational Resources Information Center

    Goodman, Ruth; Burton, Diana

    2012-01-01

    The "achievement gap"--the term typically used to refer to differences in pupil attainment associated with social class, ethnicity and gender--remains an enduring obstacle to government goals of creating a socially just society. This article explores the nature of the achievement gap and some of the mechanisms that serve to perpetuate disadvantage…

  6. 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…

  7. Making the Case for the Outlier: Researcher Reflections of an African-American Female Deputy Superintendent Who Decided to Close the Achievement Gap

    ERIC Educational Resources Information Center

    Beard, Karen Stansberry

    2012-01-01

    This article presents researcher reflections of a case study of a Black female deputy superintendent who made the value-driven decision to close the achievement gap in her district. I posit that she is an outlier because she is Black and female in a predominantly white male field of practice, she effectively closed the achievement gap through her…

  8. Public Perceptions of the Pay Gap

    ERIC Educational Resources Information Center

    Hill, Catherine; Silva, Elena

    2005-01-01

    Women have made gains toward closing the gender pay gap during the past two decades. Much of the progress occurred during the 1980s, with smaller gains in the 1990s (Institute for Women's Policy Research 2004). Women's achievements in higher education are partly responsible for narrowing the pay gap in the 1980s and 1990s. As more women earned…

  9. Temperature dependence of the carrier lifetime in Cd{sub x}Hg{sub 1−x}Te narrow-gap solid solutions with consideration for Auger processes

    SciTech Connect

    Bazhenov, N. L. Mynbaev, K. D.; Zegrya, G. G.

    2015-04-15

    The temperature dependence of the carrier lifetime in Cd{sub x}Hg{sub 1−x}Te narrow-gap solid solutions in the temperature range 5 K < T < 300 K is analyzed within the scope of a microscopic model. Main attention is given to an analysis of the Auger recombination mechanism governing the carrier lifetime at high temperatures. The Auger-recombination rates are calculated with consideration for specific features of the band structure of the narrow-gap semiconductor in microscopic theory. It is shown that strict account of the non-parabolicity of the electronic structure in terms of Kane’s model leads to a substantially different temperature dependence of the Auger-recombination rates, compared with the approach in which nonparabolicity is disregarded.

  10. Understanding and Addressing the Achievement Gap through Individualized Instruction and Formative Assessment

    ERIC Educational Resources Information Center

    Yeh, Stuart S.

    2010-01-01

    This article synthesizes findings regarding the development of competence and learned helplessness and factors influencing persistence and intrinsic motivation, suggests the process through which small differences in early achievement are magnified by the current structure of schools, and reviews evidence suggesting that the characteristics of a…

  11. Evaluation of a Multi-School Pilot Project Designed to Close Achievement Gaps

    ERIC Educational Resources Information Center

    Hughes, Georgia K.; Cowley, Kimberly S.; Copley, Lisa D.; Finch, Nicole L.; Meehan, Merrill L.

    2005-01-01

    The purpose of this project was to study instructional practices useful in improving the academic achievement of all students, particularly African American students. AEL staff believed that the approach of working closely with school and district personnel to provide professional development and exemplary culturally responsive instructional…

  12. The Distribution of Pedagogical Content Knowledge in Cambodia: Gaps and Thresholds in Math Achievement

    ERIC Educational Resources Information Center

    Ngo, Federick J.

    2013-01-01

    Increasing teacher quality is a major objective of recent Cambodian education policy. In mathematics education literature, pedagogical content knowledge (PCK) has emerged as a critical component of teacher quality that is strongly linked to student achievement. In this study I use data from a large survey of Cambodian schools to investigate the…

  13. The Racial, Ethnic, and Social Class Achievement Gaps: A Systems Analysis

    ERIC Educational Resources Information Center

    Gaynor, Alan Kibbe

    2012-01-01

    This system dynamics analysis draws on the literature to outline the factors commonly discussed as predictive of and, perhaps, causally related to problematic differences in academic achievement among students who vary in race, ethnicity, and social class. It first treats these as a wide-ranging set of exogenous variables, many of which interact…

  14. Inattention and Hyperactivity and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of inattention and hyperactivity among school-aged urban minority youth, causal pathways through which inattention and hyperactivity adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Methods: Literature review. Results:…

  15. Leading Schools of Excellence and Equity: Documenting Effective Strategies in Closing Achievement Gaps

    ERIC Educational Resources Information Center

    Brown, Kathleen M.; Benkovitz, Jen; Muttillo, A. J.; Urban, Thad

    2011-01-01

    Background/Context: In the Fall 2006 issue of AERJ, Hoy, Tarter, and Woolfolk Hoy identified the new construct of academic optimism as a general latent concept related to student achievement even after controlling for SES, previous performance, and other demographic variables. Through structural equation modeling, they found that the collective…

  16. Achieving Equity and Excellence: The Role of School Mental Health Providers in Shrinking Excellence Gaps

    ERIC Educational Resources Information Center

    Harris, Bryn; Plucker, Jonathan

    2014-01-01

    The United States is becoming more racially, ethnically, and linguistically diverse, yet the educational attainment of various student groups has been very uneven. For decades, educators and policymakers have been focused on minimal competencies rather than advanced achievement. Specifically, federal and state education policies have focused on…

  17. An Examination of Effective Practice: Moving toward Elimination of Achievement Gaps in Science

    ERIC Educational Resources Information Center

    Johnson, Carla C.

    2009-01-01

    This longitudinal study of middle school science teachers explored the relationship between effective science instruction, as defined by the National Science Education Standards (NRC in National science education standards. National Academy Press, Washington, DC, 1996), and student achievement in science. Eleven teachers participated in a three…

  18. Parent Involvement, Cultural Capital, and the Achievement Gap among Elementary School Children

    ERIC Educational Resources Information Center

    Lee, Jung-Sook; Bowen, Natasha K.

    2006-01-01

    This study examined the level and impact of five types of parent involvement on elementary school children's academic achievement by race/ethnicity, poverty, and parent educational attainment. The sample comprised 415 third through fifth graders who completed the Elementary School Success Profile. Hypotheses from Bourdieu's theory of cultural…

  19. Asian American and Pacific Islander Students: Equity and the Achievement Gap

    ERIC Educational Resources Information Center

    Pang, Valerie Ooka; Han, Peggy P.; Pang, Jennifer M.

    2011-01-01

    The authors studied more than 1 million Asian American and Pacific Islander (AAPI) and White seventh graders in a statewide California testing program between 2003 and 2008, examining their reading and math achievement. AAPI student performance is often reported as an aggregate in discussions of the success of schoolchildren and issues of racial…

  20. Closing the Mathematics Achievement Gap in High-Poverty Middle Schools: Enablers and Constraints

    ERIC Educational Resources Information Center

    Balfanz, Robert; Byrnes, Vaughan

    2006-01-01

    The mathematics achievement levels of U.S. students fall far behind those of other developed nations; within the United States itself, the students who are falling behind come predominantly from high-poverty and high-minority areas. This article reports on a series of analyses that followed 4 cohorts of students from 3 such schools through the 5th…

  1. Exploring the Middle School Science Achievement Gap: Influences of Curriculum, Instruction and Students' Perceptions

    ERIC Educational Resources Information Center

    Winning, Rosalie Anne

    2012-01-01

    Students' science achievement has been subject to scrutiny and criticism in the United States. The decline in rankings on standardized international assessments has been the focus of concern for educators, policy makers, parents and society at large. This study, designed as an action research, explored the factors contributing to the decrease…

  2. Aggression and Violence and the Achievement Gap among Urban Minority Youth

    ERIC Educational Resources Information Center

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of aggression and violence among school-aged urban minority youth, causal pathways through which aggression and violence adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Methods: Literature review. Results: Recent national data…

  3. A Pipeline Program for Urban Community Teachers: Standing in the Gap of Achievement and Possibility

    ERIC Educational Resources Information Center

    Hill, Djanna; Newton, Roberta M.

    2010-01-01

    "Paterson Teachers for Tomorrow" is a project designed to attract high school students from Paterson, NJ to careers in teaching. This article is based on an exploration of high school students' sense of self, college awareness and preparedness, and academic achievement during a year-long pre-college program. Data indicate that students developed a…

  4. Latino English Language Learners: Bridging Achievement and Cultural Gaps between Schools and Families

    ERIC Educational Resources Information Center

    Good, Mary Ellen; Masewicz, Sophia; Vogel, Linda

    2010-01-01

    This qualitative study grounded in critical inquiry and cultural-ecological theory explores barriers to academic achievement for Latino English language learners (ELLs). Parents and teachers were purposefully selected from a rural school district in the Rocky Mountain region to participate in focus group interviews. Findings included barriers…

  5. Actively Closing the Gap? Social Class, Organized Activities, and Academic Achievement in High School

    ERIC Educational Resources Information Center

    Morris, David S.

    2015-01-01

    Participation in Organized Activities (OA) is associated with positive behavioral and developmental outcomes in children. However, less is known about how particular aspects of participation affect the academic achievement of high school students from different social class positions. Using the Education Longitudinal Study of 2002, this study…

  6. Coincidence or Conspiracy? Whiteness, Policy and the Persistence of the Black/White Achievement Gap

    ERIC Educational Resources Information Center

    Gillborn, David

    2008-01-01

    Adopting an approach shaped by critical race theory (CRT) the paper proposes a radical analysis of the nature of race inequality in the English educational system. Focusing on the relative achievements of White school leavers and their Black (African Caribbean) peers, it is argued that long standing Black/White inequalities have been obscured by a…

  7. Three Essays on Grade Configuration, Academic Achievement, and the Gender Gap

    ERIC Educational Resources Information Center

    Parekh, Charles

    2010-01-01

    This dissertation is comprised of three essays exploring the performance of students on standardized tests in public schools. Since the passage of the "No Child Left Behind Act" (NCLB) in 2002, public schools have been subject to penalties for poor student achievement. In particular, NCLB requires states to measure reading and math test scores…

  8. The Achievement Gap among Newcomer Immigrant Adolescents: Life Stressors Hinder Latina/o Academic Success

    ERIC Educational Resources Information Center

    Patel, Sita G.; Barrera, Alinne Z.; Strambler, Michael J.; Muñoz, Ricardo F.; Macciomei, Erynn

    2016-01-01

    This study compares life stressors and school outcomes among newcomer immigrant adolescents from Latin America, Asia, and the Caribbean. Participants attended a predominantly low-income, urban international public high school in the northeast. The Latina/o students were exposed to more life stressors and had lower attendance and achievement than…

  9. Nonlinear Gompertz Curve Models of Achievement Gaps in Mathematics and Reading

    ERIC Educational Resources Information Center

    Cameron, Claire E.; Grimm, Kevin J.; Steele, Joel S.; Castro-Schilo, Laura; Grissmer, David W.

    2015-01-01

    This study examined achievement trajectories in mathematics and reading from school entry through the end of middle school with linear and nonlinear growth curves in 2 large longitudinal data sets (National Longitudinal Study of Youth--Children and Young Adults and Early Childhood Longitudinal Study--Kindergarten Cohort [ECLS-K]). The S-shaped…

  10. Beyond Brown v. Board of Education: The Need to Remedy the Achievement Gap.

    ERIC Educational Resources Information Center

    Klein, Dora W.

    2002-01-01

    Address the need to remedy the disparity in academic achievement of black and white students and examines why this disparity continues to exist in spite of the desegregation decrees issued under "Brown." Reviews how a court decides whether a school district has complied with a desegregation decree. Explains why schools are being released from…

  11. Analyzing the Gender Gap in Math Achievement: Evidence from a Large-Scale US Sample

    ERIC Educational Resources Information Center

    Cheema, Jehanzeb R.; Galluzzo, Gary

    2013-01-01

    The US portion of the Program for International Student Assessment (PISA) 2003 student questionnaire comprising of 4,733 observations was used in a multiple regression framework to predict math achievement from demographic variables, such as gender, race, and socioeconomic status, and two student-specific measures of perception, math anxiety and…

  12. Exploring the middle school science achievement gap: Influences of curriculum, instruction and students' perceptions

    NASA Astrophysics Data System (ADS)

    Winning, Rosalie Anne

    Students' science achievement has been subject to scrutiny and criticism in the United States. The decline in rankings on standardized international assessments has been the focus of concern for educators, policy makers, parents and society at large. This study, designed as an action research, explored the factors contributing to the decrease in the number of students attaining advanced proficiency in science learning as measured by state assessments in grades four and eight in a New Jersey school district. Specifically, this study addressed the degree to which the middle school curriculum reflected the national science framework standards for 21st century leaning and the New Jersey Core Curriculum Content Standards; the pedagogical approaches regularly planned and implemented in the middle school science classrooms; and the students' perceptions of their science learning. Research data were collected by teacher and student surveys, focus group discussions, student interviews, document reviews of written curricula, and classroom observations. An important disparity emerged between the document analysis of the local curriculum and the teachers' views that 21st century learning skills are reflected in the written curriculum and classroom pedagogy. Further, classroom observations revealed the prevalence of a traditional pedagogy, focused on repetition of teacher-disseminated information and featuring limited differentiation, inquiry-based or constructivist learning strategies. The students expressed a value for discovery and collaboration with peers in order to develop, share and refine their understanding of science. The research concluded with recommendations for a revised curriculum process, sustained and collaborative professional development, on-going formative assessments of student learning and the formal integration of an online student science blog as a means of encouraging the co-construction of deep and enduring science knowledge.

  13. The Impact of Resources on Education: A Position Paper on How Theories of Social Capital Provide Insight on the Achievement Gap in the United States Education System

    ERIC Educational Resources Information Center

    Zeisler, Kayla

    2012-01-01

    Research has shown that there is a gap in educational achievement between socioeconomic and racial groups in the public education system in the United States. This paper identifies the link between resources and academic achievement. Through examining educational resources, from in-school factors, such as facilities and teacher quality, to…

  14. Is Montgomery County's Housing Policy One Answer to Baltimore's Education Achievement Gap? The Abell Report. Volume 24, No.3

    ERIC Educational Resources Information Center

    Schwartz, Heather L.

    2011-01-01

    In 1966, the Coleman Report firmly established the link between a family's socioeconomic status and a child's educational outcomes. Known as the "income achievement gap," the disparity between the achievement of poor and rich children has become entrenched in our nation's educational landscape: with few exceptions, schools…

  15. Examining the Black-White Achievement Gap among Low-Income Children Using the NICHD Study of Early Child Care and Youth Development

    ERIC Educational Resources Information Center

    Burchinal, Margaret; McCartney, Kathleen; Steinberg, Laurence; Crosnoe, Robert; Friedman, Sarah L.; McLoyd, Vonnie; Pianta, Robert

    2011-01-01

    The Black-White achievement gap in children's reading and mathematics school performance from 4.5 years of age through fifth grade was examined in a sample of 314 lower income American youth followed from birth. Differences in family, child care, and schooling experiences largely explained Black-White differences in achievement, and instructional…

  16. Achieving a sustainable service advantage.

    PubMed

    Coyne, K P

    1993-01-01

    Many managers believe that superior service should play little or no role in competitive strategy; they maintain that service innovations are inherently copiable. However, the author states that this view is too narrow. For a company to achieve a lasting service advantage, it must base a new service on a capability gap that competitors cannot or will not copy. PMID:10123422

  17. Crystal and electronic structures and high-pressure behavior of AgSO4, a unique narrow band gap antiferromagnetic semiconductor: LDA(+U) picture.

    PubMed

    Derzsi, Mariana; Stasiewicz, Juliusz; Grochala, Wojciech

    2011-09-01

    We demonstrate that DFT calculations performed with the local density approximation (LDA) allow for significantly better reproduction of lattice constants, the unit cell volume and the density of Ag(II)SO(4) than those done with generalized gradient approximation (GGA). The LDA+U scheme, which accounts for electronic correlation effects, enables the accurate prediction of the magnetic superexchange constant of this strongly correlated material and its band gap at the Fermi level. The character of the band gap places the compound on the borderline between a Mott insulator and a charge transfer insulator. The size of the band gap (0.82 eV) indicates that AgSO(4) is a ferrimagnetic semiconductor, and possibly an attractive material for spintronics. A bulk modulus of 27.0 GPa and a compressibility of 0.037 GPa(-1) were determined for AgSO(4) from the third-order Birch-Murnaghan isothermal equation of state up to 20 GPa. Several polymorphic types compete with the ambient pressure P-1 phase as the external pressure is increased. The P-1 phase is predicted to resist pressure-induced metallization up to at least 20 GPa. PMID:21267751

  18. Optical study of narrow band gap InAsxSb1 -x (x =0 , 0.25, 0.5, 0.75, 1) alloys

    NASA Astrophysics Data System (ADS)

    Namjoo, Shirin; Rozatian, Amir S. H.; Jabbari, Iraj; Puschnig, Peter

    2015-05-01

    The structural, electronic, and optical properties of InAs, InSb, and their ternary alloys InAsxSb1 -x (x =0.25 , 0.5, 0.75) are investigated within density functional theory utilizing the wien2k package. We find that the lattice constants and bulk moduli as a function of x are in best agreement with Vegard's linear rule. When computing the electronic band structures with the modified Becke-Johnson exchange-correlation functional (mBJLDA), our results for the band gaps of InAs, InSb, and their ternary alloys are in good agreement with the available experimental results while the conventional Wu-Cohen generalized gradient approximation (GGA) functional leads to zero or close to zero band gaps. In particular, our mBJLDA results confirm experimental evidence that the minimum band gap occurs for As concentrations around x ≈0.3 . Furthermore, we investigate the dielectric function of these compounds within the random phase approximation using both the Wu-Cohen GGA and the mBJLDA functionals. While the mBJLDA results of our fully first-principles calculations show good agreement of the peak positions in ɛ2(ω ) with experiments, the peaks in the optical spectra based on the Wu-Cohen GGA band structure appear redshifted compared to experiment. We further identify the interband transitions responsible for the structures in the spectra. Looking at the optical matrix element, we note that the major peaks are dominated by transition from the Sb 5 p (As 4 p ) states to In s states for InSb and InAs0.25Sb0.75 (InAs, InAs0.75Sb0.25 , and InAs0.5Sb0.5 ).

  19. A Capstone Project: Closing the Achievement Gap of English Learners in Literacy at Sunshine Elementary School Using the Gap Analysis Model

    ERIC Educational Resources Information Center

    Herrera, Juan Carlos

    2013-01-01

    This project was an alternative capstone dissertation conducted by a team of three doctoral students. The project focused on systematic and long-term underachievement of the English Language (EL) population of a single school, Sunshine Elementary, using the gap analysis model (Clark and Estes, 2008). More specifically, the purpose of the analysis…

  20. Narrowing the gap between the number of athletes who dope and the number of athletes who are caught: scientific advances that increase the efficacy of antidoping tests.

    PubMed

    Botrè, Francesco; de la Torre, Xavier; Donati, Francesco; Mazzarino, Monica

    2014-05-01

    The analytical methods developed and applied by the antidoping laboratories have been continuously evolving over the past 50 years, with the aim of keeping pace with the constant evolution of doping strategies. Despite this, the number of adverse analytical tests reported worldwide by the network of the WADA-accredited laboratories still seems to underestimate the actual number of doped athletes. We investigate the most likely causes for this gap between the likely doping rate and the detection of athletes with positive doping tests. We consider laboratory and non-laboratory reasons that contribute to this gap. More specifically, laboratory issues are focused not only on those doping practices that may still be 'invisible' at the time of a doping test, but also on the possible role of non-conventional masking strategies. These include (1) the intake of banned drugs by specific novel drug delivery systems and (2) the coadministration of prohibited and non-prohibited drugs, taking advantage of the capacity of the latter to affect the metabolism, and consequently the detection, of the former. Non-laboratory issues include the lack of a sufficient level of 'intelligent testing', with the result that, even in the cases of doped athletes, the biological samples delivered to the antidoping laboratories for analysis may not contain those target analytes whose detection (and if necessary quantification above a decision limit) constitutes an adverse analytical finding. We present proposals to improve the efficacy of the doping control policies based on the analysis of biological samples and suggest how to constantly keep up with the continuous developments of new forms of doping. PMID:24668049

  1. Tracking Achievement Gaps and Assessing the Impact of NCLB on the Gaps: An In-Depth Look into National and State Reading and Math Outcome Trends

    ERIC Educational Resources Information Center

    Lee, Jaekyung

    2006-01-01

    This study offers systematic trend analyses of NAEP national and state-level public school fourth and eighth graders' reading and math achievement results during pre-NCLB (1990-2001) and post-NCLB (2002-2005) periods. It compares post-NCLB trends in reading and math achievement with pre-NCLB trends among different racial and socioeconomic groups…

  2. The Narrowing Gap in New York City Teacher Qualifications and Its Implications for Student Achievement in High-Poverty Schools. Working Paper 10

    ERIC Educational Resources Information Center

    Boyd, Donald; Lankford, Hamilton; Loeb, Susanna; Rockoff, Jonah; Wyckoff, James

    2007-01-01

    Studies have found substantial sorting of teachers across schools, with the schools with the highest proportions of poor, non-white, and low-scoring students having the least qualified teachers as measured by certification, exam performance, and inexperience (Lankford, Loeb and Wyckoff, 2002). Yet, there have been substantial changes in the…

  3. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Pennsylvania

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Pennsylvania's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 1390 for non-Title I students and 1220 for Title I students. In 2009, the mean scale score in 4th grade reading was 1420 for non-Title I students and 1270 for Title I students. Between 2006 and 2009, the mean…

  4. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Tennessee

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Tennessee's test score trends through 2008-09. In 2004, the mean scale score on the state 4th grade reading test was 501 for non-Title I students and 486 for Title I students. In 2009, the mean scale score in 4th grade reading was 512 for non-Title I students and 495 for Title I students. Between 2004 and 2009, the mean scale…

  5. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Kentucky

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Kentucky's test score trends through 2008-09. In 2007, the mean scale score on the state 4th grade reading test was 455 for non-Title I students and 451 for Title I students. In 2009, the mean scale score in 4th grade reading was 455 for non-Title I students and 451 for Title I students. Between 2007 and 2009, the mean scale…

  6. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Maryland

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Maryland's test score trends through 2008-09. In 2004, 82% of non-Title I 4th graders and 61% of Title I 4th graders scored at the proficient level on the state reading test. In 2009, 90% of non-Title I 4th graders and 78% of Title I 4th graders scored at the proficient level in reading. Between 2004 and 2009, the percentage…

  7. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Idaho

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Idaho's test score trends through 2008-09. In 2007, the mean scale score on the state 4th grade reading test was 209 for non-Title I students and 205 for Title I students. In 2007, the mean scale score in 4th grade reading was 211 for non-Title I students and 208 for Title I students. Between 2007 and 2009, the mean scale score…

  8. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? California

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles California's test score trends through 2008-09. In 2004, the mean scale score on the state 4th grade reading test was 341 for non-Title I students and 315 for Title I students. In 2008, the mean scale score in 4th grade reading was 379 for non-Title I students and 340 for Title I students. Between 2004 and 2008, the mean scale…

  9. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Delaware

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Delaware's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 474 for non-Title I students and 464 for Title I students. In 2009, the mean scale score in 4th grade reading was 478 for non-Title I students and 467 for Title I students. Between 2006 and 2009, the mean scale…

  10. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Utah

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Utah's test score trends through 2008-09. In 2004, the mean scale score on the state 4th grade reading test was 167 for non-Title I students and 164 for Title I students. In 2009 the mean scale score in 4th grade reading was 168 for non-Title I students and 164 for Title I students. Between 2004 and 2009, the mean scale score…

  11. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Washington

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Washington's test score trends through 2008-09. Three years of comparable mean scale score data were not available from the state. In 2004, 77% of non-Title I 4th graders and 60% of Title I 4th graders scored at the proficient level on the state reading test. In 2009, 75% of non-Title I 4th graders and 61% of Title I 4th…

  12. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Massachusetts

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Massachusetts's test score trends through 2008-09. In 2006, 59% of non-Title I 4th graders and 29% of Title I 4th graders scored at the proficient level on the state reading test. In 2009, 64% of non-Title I 4th graders and 31% of Title I 4th graders scored at the proficient level in reading. Between 2006 and 2009, the…

  13. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Missouri

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Missouri's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 661 for non-Title I students and 642 for Title I students. In 2009, the mean scale score in 4th grade reading was 661 for non-Title I students and 648 for Title I students. Between 2006 and 2009, there was no…

  14. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? New Hampshire

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles New Hampshire's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 445 for non-Title I students and 438 for Title I students. In 2009, the mean scale score in 4th grade reading was 448 for non-Title I students and 441 for Title I students. Between 2006 and 2009, the mean…

  15. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Arizona

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Arizona's test score trends through 2008-09. In 2005, the mean scale score on the state 4th grade reading test was 478 for non-Title I students and 445 for Title I students. In 2008, the mean scale score in 4th grade reading was 477 for non-title I students and 450 for title I students. Between 2005 and 2008, the mean scale…

  16. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Rhode Island

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Rhode Island's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 445 for non-Title I students and 435 for Title I students. In 2009, the mean scale score in 4th grade reading was 448 for non-Title I students and 440 for Title I students. Between 2006 and 2009, the mean…

  17. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? North Carolina

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles North Carolina's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade math test was 351 for non-Title I students and 347 for Title I students. In 2009, the mean scale score in 4th grade math was 354 for non-Title I students and 350 for Title I students. Between 2006 and 2009, the mean scale…

  18. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Kansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Kansas' test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 80 for non-Title I students and 73 for Title I students. In 2009, the mean scale score in 4th grade reading was 84 for non-Title I students and 78 for Title I students. Between 2006 and 2009, the mean scale score…

  19. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Maine

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Maine's test score trends through 2008-09. In 2006, the mean scale score on the state 4th grade reading test was 445 for non-Title I students and 438 for Title I students. In 2009, the mean scale score in 4th grade reading was 477 for non-Title I students and 441 for Title I students. Between 2006 and 2009, the mean scale score…

  20. State Test Score Trends through 2008-09, Part 4: Is Achievement Improving and Are Gaps Narrowing for Title I Students? Texas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Texas's test score trends through 2008-09. In 2005, the mean scale score on the state 4th grade reading test was 2297 for non-Title I students and 2207 for Title I students. In 2009, the mean scale score in 4th grade reading was 2334 for non-Title I students and 2235 for Title I students. Between 2005 and 2009, the mean scale…