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: A Case Study of an Urban School

    ERIC Educational Resources Information Center

    Lugo, Rosalinda

    2010-01-01

    The goal of this case study was to identify the cultural norms, practices, and programs of an urban school that narrowed the achievement gap. The reason for identifying these factors in a successful school was to add to the body of literature regarding the achievement gap and what a struggling school was able to do to narrow the gap. This case…

  3. Mind the Gaps: How College Readiness Narrows Achievement Gaps in College Success

    ERIC Educational Resources Information Center

    ACT, Inc., 2010

    2010-01-01

    This report discusses factors that contribute to lower college success rates among underrepresented racial/ethnic minority students and students from lower-income families. The report also shows that "racial/ethnic and family income gaps in college success rates narrow substantially among students who are ready for college." Everyone needs to…

  4. Striving for Equity: District Leadership for Narrowing the Opportunity and Achievement Gaps

    ERIC Educational Resources Information Center

    Smith, Robert G.; Brazer, S. David

    2016-01-01

    Based on in-depth interviews, "Striving for Equity" brings to light the complex and illuminating stories of thirteen longtime superintendents--all leaders of the Minority Student Achievement Network (MSAN)--who were able to make progress toward narrowing opportunity and achievement gaps in traditional school districts with diverse…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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.

  10. 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

  11. Comprehensive School Reform: Meta-Analytic Evidence of Black-White Achievement Gap Narrowing.

    PubMed

    Gorey, Kevin M

    2009-12-30

    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.

  12. Achievement Gaps for Students with Disabilities: Stable, Widening, or Narrowing on a State-Wide Reading Comprehension Test?

    ERIC Educational Resources Information Center

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

    2016-01-01

    Reading comprehension growth trajectories from 3rd to 7th grade were estimated for 99,919 students on a state reading comprehension assessment. We examined whether differences between students in general education (GE) and groups of students identified as exceptional learners were best characterized as stable, widening, or narrowing. The groups…

  13. Which Achievement Gap?

    ERIC Educational Resources Information Center

    Anderson, Sharon; Medrich, Elliott; Fowler, Donna

    2007-01-01

    From the halls of Congress to the local elementary school, conversations on education reform have tossed around the term "achievement gap" as though people all know precisely what that means. As it's commonly used, "achievement gap" refers to the differences in scores on state or national achievement tests between various…

  14. Narrow gap electronegative capacitive discharges

    SciTech Connect

    Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J.

    2013-10-15

    Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage V{sub rf}=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density n{sub e0} is depressed below the density n{sub esh} at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at V{sub rf}=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

  15. 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…

  16. 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…

  17. 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.

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. Gap narrowing in charged and doped silicon nanoclusters

    NASA Astrophysics Data System (ADS)

    Titov, Andrey; Michelini, Fabienne; Raymond, Laurent; Kulatov, Erkin; Uspenskii, Yurii A.

    2010-12-01

    The gap narrowing in charged Si35H36 and n -type doped Si34DH36 ( D=P , As, Sb, S, Se, and Te) clusters is studied within the GW approximation, including energy dependence of the dielectric matrix and local-field effects. It is shown that the density functional theory does not properly describe the gap narrowing in clusters, as it was found earlier in bulk Si. The main mechanisms of this effect in clusters are the same as in bulk Si: (i) the screened exchange interaction between additional electrons and (ii) the extra screening of the Coulomb interaction by additional electrons. At the same time, our calculations show that the carrier-induced gap narrowing has peculiar features in the clusters. A much weaker screening of the electron-electron interaction strongly increases the first and decreases the second mechanism of gap narrowing in Si clusters as compared to bulk Si. We find also that the gap-narrowing effect is more pronounced in doped clusters than in charged ones due to the charge localization near impurity ions. The electronic spectrum of the charged and doped Si clusters with one electron is spin split. The local-density approximation calculation greatly underestimates the value of the spin splitting. A calculation performed with the screened Hartree-Fock method shows that the splitting is large. It considerably narrows the gap and brings important spin effects into cluster properties.

  5. 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

  6. 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.

  7. Narrow band gap conjugated polymers for emergent optoelectronic technologies

    NASA Astrophysics Data System (ADS)

    Azoulay, Jason D.; Zhang, Benjamin A.; London, Alexander E.

    2015-09-01

    Conjugated organic molecules effectively produce and harvest visible light and find utility in a variety of emergent optoelectronic technologies. There is currently interest in expanding the scope of these materials to extend functionality into the infrared (IR) spectral regions and endow functionality relevant in emergent technologies. Developing an understanding of the interplay between chemical and electronic structure in these systems will require control of the frontier orbital energetics (separation, position, and alignment), ground state electronic configurations, interchain arrangements, solid-state properties, and many other molecular features with synthetic precision that has yet to be demonstrated. Bridgehead imine substituted 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) structural units, in combination with strong acceptors with progressively delocalized π-systems, afford modular donor-acceptor copolymers with broad and long wavelength absorption that spans technologically relevant wavelength (λ) ranges from 0.7 < λ < 3.2 μm.1 Here we demonstrate that electronic and structural manipulation play a major role in influencing the energetics of these systems and ultimately controlling the band gap of the materials. These results bear implication in the development of very narrow band gap systems where precise control will be necessary for achieving desired properties such as interactions with longer wavelength light.

  8. 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…

  9. Lifting Minority Achievement: Complex Answers. The Achievement Gap.

    ERIC Educational Resources Information Center

    Viadero, Debra; Johnston, Robert C.

    2000-01-01

    This fourth in a four-part series on why academic achievement gaps exist describes the Minority Achievement Committee scholars program at Shaker Heights High School in Cleveland, Ohio, a powerful antidote to the achievement gap between minority and white and Asian American students. It explains the need to break down stereotypes about academic…

  10. The "Developing" Achievement Gap: Colombian Voucher Reform

    ERIC Educational Resources Information Center

    Stern, Jonathan M. B.

    2014-01-01

    The achievement gap in many developing countries is defined in terms of rich/poor and public/private. The prevailing explanation for the "developing" achievement gap is an underfunded, inefficient, and/or inadequately supplied public school sector. Via an analysis of a Colombian voucher experiment, this article examines the extent to…

  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. 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.

  13. 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.

  14. 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,…

  15. 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,…

  16. Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials.

    PubMed

    Song, Justin C W; Kats, Mikhail A

    2016-12-14

    Carrier dynamics acquire a new character in the presence of Bloch-band Berry curvature, which naturally arises in gapped Dirac materials (GDMs). Here, we argue that photoresponse in GDMs with small band gaps is dramatically enhanced by Berry curvature. This manifests in a giant and saturable Hall photoconductivity when illuminated by circularly polarized light. Unlike Hall motion arising from a Lorentz force in a magnetic field, which impedes longitudinal carrier motion, Hall photoconductivity arising from Berry curvature can boost longitudinal carrier transport. In GDMs, this results in a helicity-dependent photoresponse in the Hall regime, where photoconductivity is dominated by its Hall component. We find that the induced Hall conductivity per incident irradiance is enhanced by up to 6 orders of magnitude when moving from the visible regime (with corresponding band gaps) to the far infrared. These results suggest that narrow-gap GDMs are an ideal test-bed for the unique physics that arise in the presence of Berry curvature and open a new avenue for infrared and terahertz optoelectronics.

  17. An evaluation of the narrowing gender gap in DUI arrests.

    PubMed

    Robertson, Angela A; Liew, Hui; Gardner, Sheena

    2011-07-01

    Although males account for the vast majority of those convicted of driving under the influence of alcohol and/or other drugs (DUI), female DUI convictions have increased over the past two decades. In this study, we examined the ratio of males-to-females who were court-mandated between the years 1992 and 2008 to attend the Mississippi Alcohol Safety Education Program (MASEP), a DUI intervention program in Mississippi. The data for this study came from MASEP records; the Behavioral Risk Factor Surveillance System (BRFSS); the Uniform Crime Reports (UCR); the Treatment Episode Data Set (TEDS); the National Household Travel Survey (NHTS); and National Highway Traffic Safety Administration (NHTSA), an agency within the US Department of Transportation. Augmented Dickey-Fuller (ADF) tests were used to assess the nature (i.e., convergence, divergence, or stability) of this trend and to identify predictors. The results showed that, over the 17-year period, the gender gap in DUI convictions, self-reported history of prior arrest, official drug arrests, and substance abuse treatment admissions has narrowed considerably. Results from the autoregressive integrated moving average (ARIMA) models show that three factors account for increases in the proportion of women mandated to attend MASEP: self-reported arrest prior to the DUI conviction, female admissions to substance abuse treatment, and annual miles driven. Changes in both women's behavior and law enforcement practices have increased female exposure to DUI arrests and narrowed the gender gap in DUI convictions.

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

    SciTech Connect

    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

    2016-07-21

    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.

  19. 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…

  20. 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…

  1. High Intensity Laser Interactions with Narrow Gap Semiconductors

    NASA Astrophysics Data System (ADS)

    Hasselback, Michael Peter

    1995-01-01

    Two-photon absorption in solids is a well known and thoroughly characterized nonlinear optical process. Higher order multi-photon absorption however, has received comparatively little study. In this dissertation, results of experiments with bulk, narrow gap semiconductors InSb and InAs are reported. By performing Z-scans and pump-probe measurements at different laser wavelengths and sample temperatures, various nonlinear optical processes are identified. Data obtained with InAs is consistent with photocarrier generation by three and four-photon absorption. It is believed this is the first direct evidence of four-photon absorption in a semiconductor. Leakage two-photon is observed with InSb at 15K. This novel effect arises from dynamic band un-blocking caused by laser heating of conduction electrons. All phenomena are excited with picosecond CO_2 laser pulses at irradiances below the material damage threshold. Physical models describing the observations are presented.

  2. Shearing flow from transient bubble oscillations in narrow gaps

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    The flow driven by a rapidly expanding and collapsing cavitation bubble in a narrow cylindrical gap is studied with the volume of fluid method. The simulations reveal a developing plug flow during the early expansion followed by flow reversal at later stages. An adverse pressure gradient leads to boundary layer separation and flow reversal, causing large shear stress near the boundaries. Analytical solution to a planar pulsating flow shows qualitative agreement with the CFD results. The shear stress close to boundaries has implications to deformable objects located near the bubble: Experiments reveal that thin, flat biological cells entrained in the boundary layer become stretched, while cells with a larger cross section are mainly transported with the flow.

  3. 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…

  4. 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…

  5. Neuroanatomical Correlates of the Income Achievement Gap

    PubMed Central

    Mackey, Allyson P.; Finn, Amy S.; Leonard, Julia A.; Jacoby Senghor, Drew S.; West, Martin R.; Gabrieli, Christopher F.O.; Gabrieli, John D. E.

    2015-01-01

    In the United States, the difference in academic achievement between higher- and lower-income students (i.e., the income achievement gap) is substantial and growing. Here, we investigated neuroanatomical correlates of this gap in adolescents (n = 58) in whom academic achievement was measured by statewide standardized testing. Cortical gray matter volume was significantly greater in students from higher-income backgrounds (n = 35) compared to students from lower-income backgrounds (n = 23), but cortical white matter volume and total cortical surface area did not differ between groups. Cortical thickness in all lobes of the brain was greater in students from higher-income than lower-income backgrounds. Thicker cortex, particularly in temporal and occipital lobes, was associated with better test performance. These results represent the first evidence that cortical thickness differs across broad swaths of the brain between higher- and lower-income students, and that cortical thickness is related to academic achievement test scores. PMID:25896418

  6. 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…

  7. 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…

  8. 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.)…

  9. 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"…

  10. 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…

  11. 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…

  12. Indian power generation market: Narrowing the gap between supply & demand

    SciTech Connect

    Wilson, R.

    1997-01-01

    It is estimated that per capita consumption of electricity in India is less than 350 kWh per year, an extremely low level by world standards. India accounts for 16% of the world`s population, but only 3% of world energy consumption. Massive investments, as much as US $10 billion over the next five years, are needed to narrow the gap between supply and demand. Power sector policy reforms dating back to 1991 have encouraged private investors, but the lndian bureaucracy itself still bubbles with protectionist leanings and corruption, resulting in delays and inefficiencies. Stakes in the Indian power sector are so high, however, that investor interest is still keen. Most predict better than double-digit growth in the Indian energy sector through 2000. Those who have been persistent in courting the India power sector will eventually reap the rewards. This paper describes some of the projects in the works at present and the companies and equipment manufacturers involved. 6 figs.

  13. Magnetic Counterpart of Persistent Photoconductivity in Narrow-Gap Semiconductors

    NASA Astrophysics Data System (ADS)

    Vasil'ev, Alexander; Voloshok, Tatyana; Warchulska, Jolanta; Kageyama, Hiroshi

    2001-08-01

    At low temperatures, some ionic, covalent and mixed bonding compounds, as well as semiconducting heterostructures and quantum wells exhibit persistent photoconductivity. This term is used to describe the striking phenomenon in which the conductivity of these compounds and/or structures is observed to be greatly enhanced by visible or infrared illumination and the low resistance state is maintained for a long time after switching off the illumination. To describe this effect in variously doped ionic-covalent semiconductors, models of repulsive barriers for both electron emission and capture were introduced based primarily on the assumption of dopants displacement in the host's crystal lattice. Here we report on the magnetic counterpart of this phenomenon, which however does not exactly meet the expectations based on transport measurements. It was found that the magnetic response of AIVBVI narrow-gap semiconductors doped with CIII impurities possesses features of both relaxation phenomena and light-induced phase transition. Exposure of PbTe:Ga, PbTe:In and Pb0.75Sn0.25Te:In single crystals to white-light illumination at low temperatures resulted initially in an increase of the diamagnetic response and then in the appearance of a sharp paramagnetic peak upon heating.

  14. 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.

  15. 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.

  16. 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…

  17. 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).…

  18. Sustaining Success toward Closing the Achievement Gap: A Case Study of One Urban High School

    ERIC Educational Resources Information Center

    Cabrera, Kimberly Elizabeth

    2010-01-01

    Since the introduction of the Coleman Report (1966), the focus on closing the achievement gap has been a critical component of educational policy for political leaders and field research by educators. The economic crisis which California and the nation at large currently face creates a challenging situation in attempting to narrow the gap.…

  19. In the Academic and Think Tank World, Pondering Achievement-Gap Remedies Takes Center Stage.

    ERIC Educational Resources Information Center

    Roach, Ronald

    2001-01-01

    Provides highlights from a conference titled "Closing the Gap: Promising Strategies for Narrowing the Achievement Gap" held in Washington, DC and sponsored by the Brookings Institution and the Edison Schools organization. The conference included presentations by notable scholars concerning ideas and research on strategies to boost the academic…

  20. 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…

  1. Productive Pedagogies: Narrowing the Gap between Schools and Communities?

    ERIC Educational Resources Information Center

    Leat, David; Thomas, Ulrike

    2016-01-01

    There is little sign that current attempts to close the "attainment gap" are working. This article argues for a different approach to addressing the "gap," based on a community asset approach. The authors describe ongoing work on community curriculum making in North-East England, in which schools undertake projects using…

  2. 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…

  3. Environmental contributors to the achievement gap.

    PubMed

    Miranda, Marie Lynn; Kim, Dohyeong; Reiter, Jerome; Overstreet Galeano, M Alicia; Maxson, Pamela

    2009-11-01

    Extensive research shows that blacks, those of low socioeconomic status, and other disadvantaged groups continue to exhibit poorer school performance compared with middle and upper-class whites in the United States' educational system. Environmental exposures may contribute to the observed achievement gap. In particular, childhood lead exposure has been linked to a number of adverse cognitive outcomes. In previous work, we demonstrated a relationship between early childhood lead exposure and end-of-grade (EOG) test scores on a limited dataset. In this analysis, data from the North Carolina Childhood Lead Poisoning Prevention Program surveillance registry were linked to educational outcomes available through the North Carolina Education Research Data Center for all 100 counties in NC. Our objectives were to confirm the earlier study results in a larger population-level database, determine whether there are differences in the impact of lead across the EOG distribution, and elucidate the impact of cumulative childhood social and environmental stress on educational outcomes. Multivariate and quantile regression techniques were employed. We find that early childhood lead exposure is associated with lower performance on reading EOG test scores in a clear dose-response pattern, with the effects increasingly more pronounced in moving from the high end to the low end of the test score distribution. Parental educational attainment and family poverty status also affect EOG test scores, in a similar dose-response fashion, with the effects again most pronounced at the low end of the EOG test score distribution. The effects of environmental and social stressors (especially as they stretch out the lower tail of the EOG distribution) demonstrate the particular vulnerabilities of socioeconomically and environmentally disadvantaged children. Given the higher average lead exposure experienced by African American children in the United States, lead does in fact explain part of the

  4. Achievement Gap and Sustainability: A Case Study of an Elementary School Bridging the Achievement Gap

    ERIC Educational Resources Information Center

    Gray, Sandra Jean

    2010-01-01

    The achievement gap problem is a growing phenomenon in the United States of America. In many schools, minority student populations are failing at alarming rates and are looking at different outcomes than those of their White and Asian counterparts. However, a few schools are breaking through the barriers of poverty, poor school attendance, low…

  5. 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.

  6. 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.

  7. 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…

  8. Oscillatory quantum interference effects in narrow-gap semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Lillianfeld, R. B.; Kallaher, R. L.; Heremans, J. J.; Chen, Hong; Goel, N.; Chung, S. J.; Santos, M. B.; Van Roy, W.; Borghs, G.

    2010-01-01

    We investigate quantum interference phenomena in narrow bandgap semiconductors under strong spin-orbit interaction, by measuring the magnetoresistance across mesoscopic closed-path structures fabricated in two-dimensional electron systems. We discuss our results in terms of four quantum interference effects brought about by geometric phases acquired by the electron wave functions: the Aharonov-Bohm phase, the Altshuler-Aronov-Spivak effect, the Berry's phase due to the evolution of the spin degree of freedom, and the Aharonov-Casher phase.

  9. Oxygen vacancy induced band gap narrowing of ZnO nanostructures by an electrochemically active biofilm

    NASA Astrophysics Data System (ADS)

    Ansari, Sajid Ali; Khan, Mohammad Mansoob; Kalathil, Shafeer; Nisar, Ambreen; Lee, Jintae; Cho, Moo Hwan

    2013-09-01

    Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports a simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, Raman spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy confirmed the oxygen vacancy and band gap narrowing of m-ZnO. m-ZnO enhanced the visible light catalytic activity for the degradation of different classes of dyes and 4-nitrophenol compared to p-ZnO, which confirmed the band gap narrowing because of oxygen defects. This study shed light on the modification of metal oxide nanostructures by EAB with a controlled band structure.Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports a simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, X

  10. 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…

  11. 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.

  12. 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,…

  13. 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…

  14. School Quality and the Black-White Achievement Gap

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Rivkin, Steven G.

    2007-01-01

    Substantial uncertainty exists about the impact of school quality on the black-white achievement gap. Our results, based on both Texas Schools Project (TSP) administrative data and the Early Childhood Longitudinal Survey (ECLS), differ noticeably from other recent analyses of the black-white achievement gap by providing strong evidence that…

  15. 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)

  16. 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…

  17. 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…

  18. The Black-White Achievement Gap: Do State Policies Matter?

    ERIC Educational Resources Information Center

    Braun, Henry I.; Wang, Aubrey; Jenkins, Frank; Weinbaum, Elliot

    2006-01-01

    A longstanding issue in American education is the gap in academic achievement between majority and minority students. The goal of this study is to accumulate and evaluate evidence on the relationship between state education policies and changes in the Black-White achievement gap, while addressing some of the methodological issues that have led to…

  19. 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…

  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.

  1. Closing the Minority Achievement Gap in Math

    ERIC Educational Resources Information Center

    Holloway, John H.

    2004-01-01

    Minority students face numerous academic barriers for achievement in the classroom as well as outside the school. The National Council of Teachers of Mathematics (NCTM) suggests six principles for maintaining the standard of school mathematics.

  2. Racial and gender science achievement gaps in secondary education.

    PubMed

    Bacharach, Verne R; Baumeister, Alfred A; Furr, R Michael

    2003-03-01

    A substantial disparity exists for academic achievement in science between Black and White primary-school children. A similar gap exists between boys and girls. The extent to which secondary education influences these achievement gaps has not been established. The authors report analyses showing how these science achievement gaps change as a function of secondary education. Analyses of data from a large, nationally representative longitudinal study of academic achievement showed that racial disparities and disparities associated with gender continue to increase throughout high school.

  3. 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…

  4. 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...

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. Narrowing the Gap in Outcomes for Vulnerable Groups. A Review of the Research Evidence: Summary of Key Findings

    ERIC Educational Resources Information Center

    Kendall, Sally; Straw, Suzanne; Jones, Megan; Springate, Iain; Lord, Pippa; Stoney, Sheila

    2007-01-01

    In 2007, the Local Government Association (LGA) commissioned the NFER to review the best evidence on what works in narrowing the gap in outcomes for vulnerable groups across the five Every Child Matters areas. The review aimed to underpin the Narrowing the Gap Programme, a major development programme being implemented by the LGA and the DCSF. …

  10. Analysis of Residual Stress for Narrow Gap Welding Using Finite Element Method

    NASA Astrophysics Data System (ADS)

    Lee, Choon Yeol; Hwang, Jae Keun; Bae, Joon Woo

    Reactor coolant loop (RCL) pipes circulating the heat generated in a nuclear power plant consist of so large diameter pipes that the installation of these pipes is one of the major construction processes. Conventionally, a shield metal arc welding (SMAW) process has been mainly used in RCL piping installations, which sometimes caused severe deformations, dislocation of main equipments and various other complications due to excessive heat input in welding processes. Hence, automation of the work of welding is required and narrow-gap welding (NGW) process is being reviewed for new nuclear power plants as an alternative method of welding. In this study, transient heat transfer and thermo-elastic-plastic analyses have been performed for the residual stress distribution on the narrow gap weldment of RCL by finite element method under various conditions including surface heat flux and temperature dependent thermo-physical properties.

  11. 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.

  12. 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.

  13. 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…

  14. 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…

  15. School Improvement for All: Reflections on the Achievement Gap.

    ERIC Educational Resources Information Center

    Howard, Gary R.

    2002-01-01

    Asserts that three social dominance issues have caused and continue to perpetuate achievement disparities among poor and minority students: the assumption of rightness, the luxury of ignorance, and the legacy of privilege. Describes school district initiatives, leadership, and research findings related to overcoming this achievement gap. Contends…

  16. 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…

  17. 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…

  18. 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.

  19. 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…

  20. From the Achievement Gap to the Education Debt: Understanding Achievement in U.S. Schools

    ERIC Educational Resources Information Center

    Ladson-Billings, Gloria

    2006-01-01

    The "achievement gap" is one of the most talked-about issues in U.S. education. The term refers to the disparities in standardized test scores between Black and White, Latina/o and White, and recent immigrant and White students. This article argues that a focus on the gap is misplaced. Instead, we need to look at the "education…

  1. 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…

  2. Charter High Schools: Closing the Achievement Gap. Innovations in Education

    ERIC Educational Resources Information Center

    US Department of Education, 2006

    2006-01-01

    The eight schools profiled in this document are serving different populations, but all of them are closing the achievement gap between low-income, minority, and special needs students and their peers. By trying out innovative new strategies, these schools are blazing a trail for others to follow. They are dispelling the myth that some students can…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. Dynamics and stability of the Townsend discharge in nitrogen in narrow gaps

    NASA Astrophysics Data System (ADS)

    Astrov, Yu. A.; Lodygin, A. N.; Portsel, L. M.

    2014-03-01

    This paper investigates the dynamics of the Townsend discharge in nitrogen in narrow gaps. To provide stability of discharge in a broad range of current, we apply a plane-parallel structure, one of the electrodes of which is made of a high-resistivity gallium arsenide. The results of experiments are analyzed in the framework of theory [Yu. P. Raizer et al., Tech. Phys. 51, 185 (2006), 10.1134/S1063784206020071], which considers the dynamics of discharge in short nitrogen-filled gaps of similar structures. According to the theory, a key parameter of discharge dynamics is time ϑ that defines the rate of discharge response to perturbations. In our work, time ϑ is experimentally found by analyzing the noise spectrum of the discharge glow in the stable and spatially uniform state of the structure. This characteristic time depends linearly on the discharge gap width, which corroborates conclusions based on the standard model of Townsend discharge. However, its values are substantially shorter compared to those predicted by theory. The relationship between ϑ and experimentally observed critical current density for the oscillatory instability, jcr, is applied to find the discharge negative differential resistance for a set of parameters of the discharge gap.

  8. 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

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

    DOE PAGES

    Guo, Shaojun; Andrew F. Fidler; He, Kai; ...

    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

  10. 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.

  11. 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…

  12. 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…

  13. Cross-disciplinary research in cancer: an opportunity to narrow the knowledge-practice gap.

    PubMed

    Urquhart, R; Grunfeld, E; Jackson, L; Sargeant, J; Porter, G A

    2013-12-01

    Health services researchers have consistently identified a gap between what is identified as "best practice" and what actually happens in clinical care. Despite nearly two decades of a growing evidence-based practice movement, narrowing the knowledge-practice gap continues to be a slow, complex, and poorly understood process. Here, we contend that cross-disciplinary research is increasingly relevant and important to reducing that gap, particularly research that encompasses the notion of transdisciplinarity, wherein multiple academic disciplines and non-academic individuals and groups are integrated into the research process. The assimilation of diverse perspectives, research approaches, and types of knowledge is potentially effective in helping research teams tackle real-world patient care issues, create more practice-based evidence, and translate the results to clinical and community care settings. The goals of this paper are to present and discuss cross-disciplinary approaches to health research and to provide two examples of how engaging in such research may optimize the use of research in cancer care.

  14. 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.

  15. High thermal stability solution-processable narrow-band gap molecular semiconductors.

    PubMed

    Liu, Xiaofeng; Hsu, Ben B Y; Sun, Yanming; Mai, Cheng-Kang; Heeger, Alan J; Bazan, Guillermo C

    2014-11-19

    A series of narrow-band gap conjugated molecules with specific fluorine substitution patterns has been synthesized in order to study the effect of fluorination on bulk thermal stability. As the number of fluorine substituents on the backbone increase, one finds more thermally robust bulk structures both under inert and ambient conditions as well as an increase in phase transition temperatures in the solid state. When integrated into field-effect transistor devices, the molecule with the highest degree of fluorination shows a hole mobility of 0.15 cm(2)/V·s and a device thermal stability of >300 °C. Generally, the enhancement in thermal robustness of bulk organization and device performance correlates with the level of C-H for C-F substitution. These findings are relevant for the design of molecular semiconductors that can be introduced into optoelectronic devices to be operated under a wide range of conditions.

  16. Narrowing Care Gaps for Early Language Delay: A Quality Improvement Study

    PubMed Central

    Brown, Courtney M.; Beck, Andrew F.; Steuerwald, Wendy; Alexander, Elizabeth; Samaan, Zeina M.; Kahn, Robert S.; Mansour, Mona

    2016-01-01

    Background and Objective Poverty is a risk factor for both language delay and failure to access appropriate therapies. The objective of this study was to increase the percentage of children 0 to 3 years old referred from an urban primary care center who attended an initial appointment with speech pathology or audiology within 60 days from 40% to 60%. Methods The Model for Improvement was used to develop and test the intervention, which addressed potential logistical barriers faced by low-income families. Adherence was plotted on run charts in time series to assess overall improvement, and subgroups were analyzed to identify reduction in disparities. Results Median referral adherence improved from 40% to 60%. Families from lower income neighborhoods had lower preintervention adherence; these differences were eliminated postintervention. Conclusions System-level changes improved access to evaluation and treatment for low-income children with language delay and narrowed the gap in access between families in lower versus higher income neighborhoods. PMID:25994319

  17. External electric field effects on AAS oscillations in narrow gap semiconductors

    NASA Astrophysics Data System (ADS)

    Lillianfeld, R. B.; Kallaher, R. L.; Davis, D. E.; Heremans, J. J.; Chen, Hong; Goel, N.; Chung, S. J.; Santos, M. B.; van Roy, W.; Borghs, G.

    2008-03-01

    We present experiments on quantum interference phenomena in semiconductors with strong spin-orbit interaction, using mesoscopic parallel ring arrays fabricated on InSb/InAlSb and InAs/AlGaSb heterostructures. A front gate modulates the spin-orbit interaction, which in turn affects the oscillatory interference phenomena. The experiments investigate the low temperature resistance of the ring arrays as a function of weak perpendicularly applied magnetic fields as well as applied gate voltage. The low field magnetoresistance in the arrays has the h/2e periodicity characteristic of Altshuler-Aronov-Spivak (AAS) oscillations. Despite reduced gate action typical of narrow-gap heterostructures (characterized by Hall measurements), we note an effect on the oscillatory magnetoresistance. The AAS oscillation magnitudes acquire a quasi-periodic modulation as function of gate voltage, and the localization background broadens at higher electron densities. The nature of these influences is examined. (NSF DMR-0618235, DMR-0080054, DMR-0209371)

  18. 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.

  19. 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.

  20. Millimeter-wave narrow-gap uncooled hot-carrier detectors for active imaging

    NASA Astrophysics Data System (ADS)

    Sizov, Fedir F.; Zabudsky, Vyacheslav V.; Golenkov, Aleksandr G.; Shevchik-Shekera, Ann

    2013-03-01

    It is shown that electron heating by electromagnetic radiation in mercury-cadmium-telluride (MCT) layers can be used for designing of uncooled terahertz (THz)/sub-THz detectors with appropriate for active imaging characteristics (noise equivalent power ˜2.6×10-10 W/Hz at ν˜140 GHz) and these detectors can be manufactured within well established MCT technologies. This narrow-gap semiconductor can be considered as a material for THz/sub-THz detectors with possibility to be assembled into arrays. The characteristics of those detectors can be controlled and improved by selection of parameters of initial layers, substrate properties, and antenna configuration. For field effect transistor detectors, even for transistors with rather long channels (˜1 μm), rather similar characteristics at ν˜140 GHz can also be obtained.

  1. 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.

  2. 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.

  3. 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.

  4. Modelling for Transient Optically Induced Metal - Transitions in Narrow-Gap Semiconductors and Semimetals.

    NASA Astrophysics Data System (ADS)

    Vidal, Jordina

    1994-01-01

    The theoretical work presented in this thesis is based on models developed to interpret a series of optical experiments with short-pulse lasers, which allow a time -domain study of phenomena on a sub-picosecond timescale. By means of a pump-probe technique, we observe large amplitude oscillations in the time domain reflectivity response of a series of narrow-gap semiconductors and semimetals. The oscillations have the frequency of the fully-symmetric optical phonon mode of the system, and are maximally displaced from their midpoint value at zero time delay between pump and probe. These features indicate that a coherent phonon vibration is generated in these materials via an electronic excitation at different points of the Brillouin zone, which displaces instantaneously the equilibrium positions of the atoms. It is precisely this generation of coherent phonons that makes the time-domain technique distinct from conventional frequency domain techniques, such as Raman and neutron scattering. Using a range of theoretical techniques, from nearly free electron models to state-of-the art ab initio calculations, I have made quantitative microscopic evaluations of the coherent phonon phenomenon. The studies focus on two unique aspects of having such coherent atomic vibrations in a narrow gap material, with special emphasis on the group V semimetals Sb and Bi. First of all, I have performed dynamical band structure calculations, as a function of the coherent atomic motion, in order to inspect the possibility of a transient metal-insulator transition at a terahertz frequency. Secondly, I have calculated the evolution of the displaced atoms in quasi-equilibrium with the laser -excited carriers, as the electron-ion coupled system returns to its ground state equilibrium. These calculations are fundamental, insofar they provide a quantitative microscopic description of the coherent phonon phenomenon. Moreover, the predicted magnitude of the atomic displacements, and the resulting

  5. 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…

  6. Influence of the Strength Mismatch of a Narrow Gap Welded Joint of SA508 on the Plastic η Factor

    NASA Astrophysics Data System (ADS)

    Koo, J. M.; Huh, Y.; Seok, C. S.

    2012-11-01

    In this article, the influence of the strength mismatch of a narrow gap welded joint of SA508 on the η factor was evaluated. The η factor is the principal parameter that determines the plastic portion of the J-integral. The specimens for tensile and hardness tests were collected from piping with narrow gap welding and the stress-strain curve and hardness were obtained from those. From these results, the Ramberg-Osgood (R-O) constant was obtained. Also, the finite element analysis was performed with variations in the strength mismatch and the weld width. The η factor equation considering the strength mismatch and the weld width of a narrow gap welded joint was suggested.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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.

  8. Investigation of Plasma Uniformity in Pulsed 100 MHz Narrow Gap-Capacitively Coupled Argon Plasma

    NASA Astrophysics Data System (ADS)

    Jang, Yunchang; Choi, Myungsun; Rho, Hyun-Joon; Huh, Sung-Ryul; Yoon, Sung-Young; Ryu, Sangwon; Kim, Gon-Ho

    2015-09-01

    Capacitively coupled plasmas (CCPs) for industrial applications have a narrow gap between two electrodes and a large exhaust region between electrodes and lateral walls. In this study, uniformity of electron density (ne) distribution was investigated in a 300 mm Φ CCP with outer-electrode space 4 times larger than inter-electrode space. The 100 MHz RF power was applied to top electrode at a pulse repetition rate of 5 kHz. Experiments reveals that the non-uniformity of the ne decreases from 0.60 in the active-glow period to 0.39 in after-glow period. In order to account for this phenomenon in the after-glow, the effective diffusion length representing the ratio of plasma generation volume to effective loss area is introduced. When RF power is turned off, the ne of each space starts to decrease with the specific loss rate determined by each leff. The calculated leff of the outer-electrode space is about 3.7 times longer than that in the outer-electrode space. This implies that ne of the outer-electrode space decay more slowly, leading to improve the uniformity. The details on experimental results and analysis will be presented and discussed. This research was supported by BK21 Research Division of Seoul National University for Energy Resources, Ministry of Trade, Industry and Energy Republic of Korea and Consortium of Semiconductor Advanced Research.

  9. Optical damping constant due to free carriers in narrow gap semiconductors

    NASA Astrophysics Data System (ADS)

    Kumazaki, K.

    1987-10-01

    Far infrared reflection spectra of narrow gap semiconductors (HgSe, Zn xHg 1- xSe and Cd xHg 1- xSe) are measured by a Fourier transform system in the range of 20 to 500cm -1 at 5 K. The spectra of these materials are analyzed by using the dynamic dielectric function as a sum of interband and intraband transitions and phonon contributions. Damping constants of free carriers are estimated from best fitting with experimental reflectivity curves. The frequency dependence of the damping constant for HgSe shows the Drude type in lower frequency than the plasma frequency. That in higher than the plasma frequency is explained well by the impurity scattering including single and collective excitations and the effect of the electron-LO phonon polar coupling. The dependence of the damping constant on the frequency for Zn xHg 1- xSe and Cd xHg 1- xSe shows the similar tendency for HgSe. The compensation in our samples is about 30% for doubly ionized impurities (donors and acceptors).

  10. 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.

  11. 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

  12. Photoinduced paramagnetism of group III impurities in AIVBVI narrow-gap semiconductors

    NASA Astrophysics Data System (ADS)

    Vasil'ev, A. N.; Voloshok, T. N.; Warchulska, J. K.; Kageyama, H.

    2001-02-01

    At low temperatures some ionic, covalent and mixed bonding compounds, as well as semiconducting heterostructures and quantum wells exhibit persistent photoconductivity. This term is used to describe the striking observation that the conductivity of these compounds and/or structures is greatly enhanced by visible or infrared illumination and that the low resistance state is maintained for a long time after switching off the illumination. To describe this effect in variously doped ionic-covalent semiconductors the models of repulsive barrier for both electron emission and capture were introduced based primarily on the assumption of dopant's displacement in the host's crystal lattice. Here we report on the magnetic counterpart of this phenomenon, which however does not exactly meet the expectations based on transport measurements. It was found that the magnetic response of AIVBVI narrow-gap semiconductors doped with CIII impurities possesses features of both relaxation phenomena and light-induced phase transition. Exposure of PbTc:Ga, PbTe:In and Pb0.75Sn0.25Te:In single crystals to white-light illumination at low temperatures resulted initially in an increase of the diamagnetic response and then in the appearance of a sharp paramagnetic peak at heating.

  13. Band gap narrowing of titanium dioxide (TiO2) nanocrystals by electrochemically active biofilms and their visible light activity

    NASA Astrophysics Data System (ADS)

    Kalathil, Shafeer; Khan, Mohammad Mansoob; Ansari, Sajid Ali; Lee, Jintae; Cho, Moo Hwan

    2013-06-01

    We report a simple biogenic-route to narrow the band gap of TiO2 nanocrystals for visible light application by offering a greener method. When an electrochemically active biofilm (EAB) was challenged with a solution of Degussa-TiO2 using sodium acetate as the electron donor, greyish blue-colored TiO2 nanocrystals were obtained. A band gap study showed that the band gap of the modified TiO2 nanocrystals was significantly reduced (Eg = 2.85 eV) compared to the unmodified white Degussa TiO2 (Eg = 3.10 eV).

  14. Band gap narrowing of titanium dioxide (TiO2) nanocrystals by electrochemically active biofilms and their visible light activity.

    PubMed

    Kalathil, Shafeer; Khan, Mohammad Mansoob; Ansari, Sajid Ali; Lee, Jintae; Cho, Moo Hwan

    2013-07-21

    We report a simple biogenic-route to narrow the band gap of TiO2 nanocrystals for visible light application by offering a greener method. When an electrochemically active biofilm (EAB) was challenged with a solution of Degussa-TiO2 using sodium acetate as the electron donor, greyish blue-colored TiO2 nanocrystals were obtained. A band gap study showed that the band gap of the modified TiO2 nanocrystals was significantly reduced (E(g) = 2.85 eV) compared to the unmodified white Degussa TiO2 (E(g) = 3.10 eV).

  15. 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.

  16. 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

  17. 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

  18. 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…

  19. 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…

  20. Toward Excellence with Equity: An Emerging Vision for Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Ferguson, Ronald F.

    2007-01-01

    For the past 15 years, economist Ronald Ferguson has investigated the myriad factors that combine to create racial disparities in academic performance. Beginning with his analysis of the impact of test scores in predicting racial wage gaps, Ferguson has explored how rates of progress in narrowing gaps have varied over the recent decades, the roles…

  1. 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

  2. Exchange interaction and rashba spin splitting effects in electron spin resonance in narrow-gap quantum wells

    SciTech Connect

    Krishtopenko, S. S.; Malyzhenkov, A. V.; Kalinin, K. P.; Ikonnikov, A. V.; Maremyanin, K. V.; Gavrilenko, V. I.; Goiran, M.

    2013-12-04

    We report a study of electron spin resonance (ESR) in a perpendicular magnetic field in n-type narrow-gap quantum well (QW) heterostructures. Using the Hartree-Fock approximation, based on the 8×8 k⋅p Hamiltonian, the many-body corrections to the ESR energy are found to be nonzero in symmetric and asymmetric narrow-gap QWs. We demonstrate a significant enhancement of the ESR energy in asymmetric QWs, induced by the Rashba spin splitting and exchange interaction, as well as the exchange-induced enhancement of the ESR energy in symmetric QWs. The ESR energies estimated for 2DEG in InAs/AlSb QWs are compared with experimental results in weak magnetic fields.

  3. The Opportunity Gap Achievement and Inequality in Education. Harvard Educational Review Reprint Series

    ERIC Educational Resources Information Center

    da Silva, Carol DeShano, Ed.; Huguley, James Philip, Ed.; Kakli, Zenub, Ed.; Rao, Radhika, Ed.

    2007-01-01

    "The Opportunity Gap" aims to shift attention from the current overwhelming emphasis on schools in discussions of the achievement gap to more fundamental questions about social and educational opportunity. The achievement gap looms large in the current era of high-stakes testing and accountability. Yet questions persist: Has the…

  4. Explanatory Factors of the Black Achievement Gap in Montreal's Public and Private Schools: A Multivariate Analysis

    ERIC Educational Resources Information Center

    Caldas, Stephen J.; Bernier, Sylvain; Marceau, Richard

    2009-01-01

    This exploratory analysis uses multiple regression modeling to help shed light on the correlates of the Black achievement gap in Montreal's public and private secondary schools. Using school-level testing data from Quebec's Ministry of Education, the authors show that there is a Black achievement gap, and that this gap is highly associated with…

  5. 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…

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

    DOE PAGES

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai-Zhuang; ...

    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

  7. Achievement Gap Elimination: Report of the Missouri K-16 Task Force.

    ERIC Educational Resources Information Center

    2002

    In 2001, Missouri's K-16 project launched the K-12 Task Force on Achievement Gap Elimination, which believes that improving teacher quality is the single most important factor in eliminating the achievement gap among Missouri students. This report describes the significance of teacher quality on student achievement, emphasizing the uneven…

  8. 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.

  9. 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

  10. Soluble narrow band gap and blue propylenedioxythiophene-cyanovinylene polymers as multifunctional materials for photovoltaic and electrochromic applications.

    PubMed

    Thompson, Barry C; Kim, Young-Gi; McCarley, Tracy D; Reynolds, John R

    2006-10-04

    A family of soluble narrow band gap donor-acceptor conjugated polymers based on dioxythiophenes and cyanovinylenes is reported. The polymers were synthesized using Knoevenagel polycondensation or Yamamoto coupling polymerizations to yield polymers with molecular weights on the order of 10 000-20 000 g/mol, which possess solubility in common organic solvents. Thin film optical measurements revealed narrow band gaps of 1.5-1.8 eV, which gives the polymers a strong overlap of the solar spectrum. The energetic positions of the band edges were determined by cyclic voltammetry and differential pulse voltammetry and demonstrate that the polymers are both air stable and show a strong propensity for photoinduced charge transfer to fullerene acceptors. Such measurements also suggest that the polymers can be both p- and n-type doped, which is supported by spectroelectrochemical results. These polymers have been investigated as electron donors in photovoltaic devices in combination with PCBM ([6,6]-phenyl C(61)-butyric acid methyl ester) as an electron acceptor based on the near ideal band structures designed into the polymers. Efficiencies as high as 0.2% (AM1.5) with short circuit current densities as high as 1.2-1.3 mA/cm(2) have been observed in polymer/PCBM (1:4 by weight) devices and external quantum efficiencies of more than 10% have been observed at wavelengths longer than 600 nm. The electrochromic properties of the narrow band gap polymers are also of interest as the polymers show three accessible color states changing from an absorptive blue or purple in the neutral state to a transmissive sky-blue or gray in the oxidized and reduced forms. The wide electrochemical range of electrochromic activity coupled with the strong observed changes in transmissivity between oxidation states makes these materials potentially interesting for application to electrochromic displays.

  11. 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…

  12. 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…

  13. 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…

  14. Experimental Characterization of Interchannel Mixing of Multiphase Flow Through a Narrow Gap

    NASA Astrophysics Data System (ADS)

    Mäkiharju, Simo A.; Gose, James W.; Buchanan, John R., Jr.; Mychkovsky, Alexander G.; Lowe, Kirk T.; Ceccio, Steven L.

    2016-11-01

    Two-phase mass transfer through a gap connecting two adjacent channels was investigated as a function of gap geometry and flow conditions. An experiment with a simplified geometry was conducted to aid in the physical understanding and to provide data for validation of numerical computations. The flow loop consisted of two (127 mm)2 channels connected by a 1,219 mm (L) x 229 mm (W) gap, the height of which could be adjusted from 0 to 50 mm. The inlet Reynolds number in each channel could be independently varied from 4x104 - 1x105. During previous experiments, the single phase mixing was extensively investigated. The inlet void fraction was varied from 1 to 20%. Gas was injected as nominally monodisperse bubbles with diameter O(5 mm). The mass transfer through the gap was determined from measurements of the flow rates of water and air, and tracer concentration taken at channel inlets/outlets. The void fraction, bubble diameter distribution and gas flux was determined at the inlets based on flow rate measurements prior to gas injection, optical probes and Wire Mesh Sensor (WMS) data. At the outlets the gas fluxes were based on WMS measurements and the liquid phase mixing was determined based on measurement of the tracer concentration and liquid flow rate after separation of gas. Imaging of fluorescent tracer dye was utilized for select conditions to examine the dynamics of the mixing.

  15. 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,…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  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. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. Psychological altruism vs. biological altruism: narrowing the gap with the Baldwin effect.

    PubMed

    Ananth, Mahesh

    2005-01-01

    This paper defends the position that the supposed gap between biological altruism and psychological altruism is not nearly as wide as some scholars (e.g., Elliott Sober) insist. Crucial to this defense is the use of James Mark Baldwin's concepts of "organic selection"and "social heredity" to assist in revealing that the gap between biological and psychological altruism is more of a small lacuna. Specifically, this paper argues that ontogenetic behavioral adjustments, which are crucial to individual survival and reproduction, are also crucial to species survival. In particular, it is argued that human psychological altruism is produced and maintained by various sorts of mimicry and self-reflection in the aid of both individual and species survival. The upshot of this analysis is that it is possible to offer an account of psychological altruism that is closely tethered to biological altruism without reducing entirely the former to the latter.

  11. Achieving biodiversity benefits with offsets: Research gaps, challenges, and needs.

    PubMed

    Gelcich, Stefan; Vargas, Camila; Carreras, Maria Jose; Castilla, Juan Carlos; Donlan, C Josh

    2017-03-01

    Biodiversity offsets are becoming increasingly common across a portfolio of settings: national policy, voluntary programs, international lending, and corporate business structures. Given the diversity of ecological, political, and socio-economic systems where offsets may be applied, place-based information is likely to be most useful in designing and implementing offset programs, along with guiding principles that assure best practice. We reviewed the research on biodiversity offsets to explore gaps and needs. While the peer-reviewed literature on offsets is growing rapidly, it is heavily dominated by ecological theory, wetland ecosystems, and U.S.-based research. Given that majority of offset policies and programs are occurring in middle- and low-income countries, the research gaps we identified present a number of risks. They also present an opportunity to create regionally based learning platforms focused on pilot projects and institutional capacity building. Scientific research should diversify, both topically and geographically, in order to support the successful design, implementation, and monitoring of biodiversity offset programs.

  12. 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.

  13. 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)…

  14. Understanding and Reversing Underachievement, Low Achievement, and Achievement Gaps among High-Ability African American Males in Urban School Contexts

    ERIC Educational Resources Information Center

    Ford, Donna Y.; Moore, James L., III

    2013-01-01

    This article focuses on the achievement gap, with attention devoted to underachievement and low achievement among African American males in urban school contexts. More specifically, the article explains problems and issues facing or confronting these Black male students in urban education settings. A central part of this discussion is grounded in…

  15. Narrow-gap semiconducting properties of KMgBi with multiband feature

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Sun, Shanshan; Lei, Hechang

    2017-01-01

    KMgBi single crystals have been grown successfully by using the Bi flux method. KMgBi shows a semiconducting behavior with a metal-semiconductor transition in high temperature regions. Moreover, both electron- and hole-type carriers exist in KMgBi with a strong temperature dependence of carrier concentrations and mobilities. These results suggest that KMgBi is a narrow-band semiconductor with multiband features in the bulk rather than a semimetal as predicted theoretically. On the other hand, KMgBi exhibits a resistivity plateau in low temperature regions, similar to other topological insulators. It implies that there might be a nontrivial topological surface state in KMgBi.

  16. 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…

  17. 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…

  18. Narrowing the gap: access to HIV treatments in developing countries. A pharmaceutical company's perspective

    PubMed Central

    Cochrane, J.

    2000-01-01

    The advent of new antiretroviral medicines means that the effects of HIV can now be curbed, but only one in twenty infected people have so far benefited. For those living in developing countries, the new treatments are practically unattainable. Governments, UNAIDS and pharmaceutical companies recognise this only too well and have rethought established assumption in order to try and overcome the challenges posed by cost, inadequate health services and unreliable local supply of medicines. Key Words: AIDS • treatment gap • developing countries • Glaxo Wellcome • access to medicines • public health PMID:10701172

  19. 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-…

  20. 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:…

  1. 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…

  2. Early College High School: Closing the Latino Achievement Gap

    ERIC Educational Resources Information Center

    Beall, Kristen Ann

    2016-01-01

    The population of United States Latino students is growing at a rapid rate but their academic achievement lags behind white and Asian students. This issue has significant consequences for the nation's economy, as the job market continues to demand more education and better skills. Early College High School programs have the potential to improve…

  3. 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'…

  4. 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…

  5. 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…

  6. 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…

  7. 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.

  8. The Achievement Gap Between African-American and Non-minority Students: How Can We Close the Gap?

    ERIC Educational Resources Information Center

    Wells, Wayne D.; Griffith, Kimberly Grantham; Kritsonis, William Allan

    2007-01-01

    The purpose of this article is to examine and search various ways we can close the achievement gap between African-American and Non-minority students within the educational system in the United States. [Note: Special note of gratitude to Dr. Kimberly Grantham Griffith for her assistance in getting this article published. See: www.nationalforum.com

  9. Absence of localized-spin magnetic scattering in the narrow-gap semiconductor FeSb2

    SciTech Connect

    Zaliznyak, Igor; Savici, Andrei T; Garlea, Vasile O; Hu, Rongwei; Petrovic, C

    2011-01-01

    We report inelastic neutron scattering measurements aimed at investigating the origin of the temperature-induced paramagnetism in the narrow-gap semiconductor FeSb2. We find that inelastic response for energies up to 60 meV and at temperatures ~ 4.2 K, ~ 300 K and ~ 550 K is consistent with scattering by the lattice phonon excitations. Hence, we observe no evidence for a well-defined magnetic excitation corresponding to transitions between the non-magnetic ground state and states of magnetic multiplet in the localized spin picture. However, a broad magnetic scattering continuum in the 15 meV to 35 meV energy range is not ruled out by our data. Our findings make description in terms of the localized Fe magnetic states unlikely and suggest that paramagnetic susceptibility of itinerant electrons is at the origin of the temperature-induced magnetism in FeSb2.

  10. Interface band gap narrowing behind open circuit voltage losses in Cu2ZnSnS4 solar cells

    NASA Astrophysics Data System (ADS)

    Crovetto, Andrea; Palsgaard, Mattias L. N.; Gunst, Tue; Markussen, Troels; Stokbro, Kurt; Brandbyge, Mads; Hansen, Ole

    2017-02-01

    We present evidence that bandgap narrowing at the heterointerface may be a major cause of the large open circuit voltage deficit of Cu2ZnSnS4/CdS solar cells. Bandgap narrowing is caused by surface states that extend the Cu2ZnSnS4 valence band into the forbidden gap. Those surface states are consistently found in Cu2ZnSnS4, but not in Cu2ZnSnSe4, by first-principles calculations. They do not simply arise from defects at surfaces but are an intrinsic feature of Cu2ZnSnS4 surfaces. By including those states in a device model, the outcome of previously published temperature-dependent open circuit voltage measurements on Cu2ZnSnS4 solar cells can be reproduced quantitatively without necessarily assuming a cliff-like conduction band offset with the CdS buffer layer. Our first-principles calculations indicate that Zn-based alternative buffer layers are advantageous due to the ability of Zn to passivate those surface states. Focusing future research on Zn-based buffers is expected to significantly improve the open circuit voltage and efficiency of pure-sulfide Cu2ZnSnS4 solar cells.

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Fourth Grade Achievement Gap in Charter Schools Mirrors MPS. Research Brief. Volume 91, Number 8

    ERIC Educational Resources Information Center

    Public Policy Forum, 2003

    2003-01-01

    Although the hope for charter schools is the lessening and eventual elimination of the achievement gap that exists by race and income, this report indicates that charter schools in Milwaukee are mirroring the test score gap of both Milwaukee Public Schools (MPS) and the state of Wisconsin in both fourth grade reading and fourth grade math. Other…

  18. 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 studies…

  19. 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…

  20. 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,…

  1. The Achievement Gap, Revisited: An Empirical Assessment of What We Can Learn from East Asian Education

    ERIC Educational Resources Information Center

    Czehut, Katherine Jessica Drake

    2012-01-01

    International mathematics assessments have established students in East Asia as among the best in the world and their U.S. counterparts as mediocre. What is not clear is why this "achievement gap" exists. The last major study to address this question, Stevenson and Stigler's (1992) "The Learning Gap," was published prior to…

  2. 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…

  3. 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)…

  4. 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

  5. Scientists in the swamp: narrowing the language-practice gap in community psychology.

    PubMed

    Hess, Jacob Z

    2005-06-01

    As a confluence of unique values and activities, the collective practice of community psychology is difficult to characterize in a simple way. Increasingly, however, professional contexts are laden with pressure to define any practice--from library work to medical interventions--in the orderly, compact language of traditional science. This trend has historically been resisted in the field by those sensing a fundamental lack of fit between the fluid, emergent aspects of community psychological practice and the fixed, precise language of classic science. In response to this "language-practice gap," some have attempted to adapt the traditional language of science to better fit the field's practice, while others have explored alternative languages of practice seemingly more indigenous to the messy "swamp" of actual communities. While the former effort leaves some theoretical contradictions intact, the latter tends to discount scientific identity entirely. This paper proposes a potential step forward by resituating questions of disciplinary language and identity within a current philosophical discourse where the nature of social science itself remains sharply contested. This suggests shifting attention away from "should we be a science?" to "what kind of science might we be after all?"; in turn, alternative languages may be re-cast as legitimate contributors to a kind of science more authentic to human communities--even a viable "science in the swamp." One such language-philosophical hermeneutics--is presented as a particularly valuable supplement to traditional science. Illustrations highlight ways that hermeneutics may advance the formal language of the field towards a closer fit of what actually happens in practice, while preserving and even bolstering the empirical rigor and scientific identity of the field.

  6. 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

  7. [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

  8. 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…

  9. 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…

  10. Developing a Perspective on the Global Achievement Gap: School Leaders as International Collaborators

    ERIC Educational Resources Information Center

    Fanning, Michael C. P.

    2007-01-01

    In recent years American schools and the scholars who study these schools have become focused on bridging the achievement gap. The scholarly literature is most often focused on the discrepancy in achievement in one school, a region, or perhaps one nation. The literature examining the best practices of schools that have bridged this gap…

  11. 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…

  12. Closing the Achievement Gap in Suburban and Urban School Communities. Policy Issue.

    ERIC Educational Resources Information Center

    Ferguson, Ronald F.; Clark, Reginald; Stewart, Judy

    This edition focuses on the topic of closing the achievement gap from the perspectives of urban and suburban school districts. After an introduction by Judy Stewart, the first article, "Addressing Racial Disparities in High-Achieving Suburban Schools" (Ronald F. Ferguson), shares findings from a recent survey of more than 34,000 students…

  13. Can Educators Close the Achievement Gap? An Interview with Richard Rothstein and Kati Haycock

    ERIC Educational Resources Information Center

    Holland, Holly

    2007-01-01

    In this article, the author interviews two leading thinkers in the field of education. Richard Rothstein and Kati Haycock talk about the possibility of closing the achievement gap through education and face off on poverty, race, and school achievement. In his book, "Class and Schools" (Teachers College Press, 2004), Rothstein writes that…

  14. Patterns of Achievement Gaps among School Districts: New Data, New Measures, New Insights

    ERIC Educational Resources Information Center

    Reardon, Sean F.; Shores, Kenneth A.; Kalogrides, Demetra; Weathers, Ericka S.

    2014-01-01

    There are nearly 14,000 school districts in the United States. Of these districts, there is very little information about the size of academic achievement gaps between whites and blacks and white and Hispanic students. This study was interested in district-level achievement patterns across the almost 14,000 school districts in the country because…

  15. Closing Achievement Gaps and Beyond: Teachers' Reactions to the Remedial Education Policy in Taiwan

    ERIC Educational Resources Information Center

    Chen, Hsiao-Lan Sharon; Yu, Patricia

    2016-01-01

    Educators have increasingly implemented remedial education in elementary and secondary schools throughout Taiwan as a systemic approach toward closing achievement gaps. However, students from lower socioeconomic backgrounds and those in remote areas have shown little improvement in academic achievement. This issue raises the question of how…

  16. 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…

  17. 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-…

  18. 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.

  19. Is "Gender Gap" Narrowing?

    ERIC Educational Resources Information Center

    Science, 1991

    1991-01-01

    The question as to whether males and females have different kinds of intellectual abilities is addressed. The evidence that there are some differences in cognition and perception between men and women is reviewed. (KR)

  20. 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.

  1. 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.

  2. 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…

  3. Addressing the Achievement Gap between Minority and Nonminority Children: Increasing Access and Achievement through Project EXCITE

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula

    2006-01-01

    Project EXCITE was developed and implemented specifically to raise the achievement of gifted minority students in a large suburban school district of Chicago so that they could qualify for advanced programs and accelerated tracks in high school in mathematics and science. This paper describes the goals, components, eligibility, and selection…

  4. 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.

  5. 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

  6. 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.

  7. 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…

  8. Achievement-Related within-School Socioeconomic Gaps in Science Subjects in China: Evidence on Existence, Consistency, and Compensation

    ERIC Educational Resources Information Center

    Ma, Xin; Yuan, Jing; Luo, Xingkai

    2016-01-01

    Using data from the 2011 (Chinese) Student Academic Achievement Evaluation, we examined whether within-school socioeconomic gaps in science achievement exist across science subjects, how consistent they are, and whether there are relationships between school average science achievement and within-school socioeconomic gaps in science achievement.…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  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 paper introduces and evaluates methods for estimating achievement gaps on a familiar standard-deviation-unit metric using data from these ordered…

  14. 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…

  15. The Educational Achievement Gap as a Social Justice Issue for Teacher Educators

    ERIC Educational Resources Information Center

    Collopy, Rachel; Bowman, Connie; Taylor, David A.

    2012-01-01

    The educational achievement gap is a critical social justice issue. Catholic and Marianist conceptions of social justice in particular call people to work with others in their spheres of life to transform institutions in order to further human rights while promoting the common good. Drawing on key elements of Catholic teaching on social justice,…

  16. 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…

  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. 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…

  19. Minority Achievement Gaps in STEM: Findings of a Longitudinal Study of Project Excite

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula; Steenbergen-Hu, Saiying; Thomson, Dana; Rosen, Rhoda

    2017-01-01

    This longitudinal study examined the outcomes of Project Excite on reducing minority students' achievement gaps in STEM over 14 years. Project Excite was designed to provide intensive supplemental enrichment and accelerated programming for high-potential, underrepresented minority students from third through eighth grades to better prepare them…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  5. The Black-White Achievement Gap: When Progress Stopped. Policy Information Report

    ERIC Educational Resources Information Center

    Barton, Paul E.; Coley, Richard J.

    2010-01-01

    This report is about understanding the periods of progress and the periods of stagnation in changes in the achievement gap that have occurred over the past several decades. The authors try to understand what might have contributed to the progress as well as probe the reasons that may account for the progress halting, in the hope of finding some…

  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. 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…

  8. "Acting White": How the Past Implementation of School Desegregation Helped Create Today's Attainment and Achievement Gaps

    ERIC Educational Resources Information Center

    Buck, Stuart

    2016-01-01

    Summarizing my prior work, the only book length treatment of the "acting White" phenomenon (Buck, 2010), I argue that while desegregation was both a moral necessity and a social good, the manner in which desegregation was implemented by White authorities led indirectly to today's achievement gaps. In the course of desegregation…

  9. 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…

  10. 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…

  11. 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…

  12. Bridging the Gap between Standards and Achievement: The Imperative for Professional Development in Education.

    ERIC Educational Resources Information Center

    Elmore, Richard F.

    This paper discusses the importance of teacher professional development to student achievement. Section 1, "The Imperative: Investment in Human Skill and Knowledge," explains that despite contradictory evidence, prevailing assumptions asserts that teachers learn most of what they need during preservice education. Section 2, "The Knowledge Gap in…

  13. Classroom Environment, Instructional Resources, and Teaching Differences in High-Performing Kentucky Schools with Achievement Gaps.

    ERIC Educational Resources Information Center

    Meehan, Merrill L.; Cowley, Kimberly S.; Schumacher, Debbie; Hauser, Brenda; Croom, Nona D. M.

    This study examined differences at the classroom level between Kentucky schools with minimum versus large gaps in academic achievement between particular groups of students. Data were gathered via observations of 213 classrooms at 18 elementary, middle, and high schools. Although all the schools were identified as high-performing in terms of…

  14. Bridging English Language Learner Achievement Gaps through Effective Vocabulary Development Strategies

    ERIC Educational Resources Information Center

    Gibson, Charles

    2016-01-01

    Despite a well-documented history of immigration in the United States of America and rise in population of students that speak a language other than English, academic achievement gaps between English Language Learners and their native English language speaking counterparts from Grades Pre-Kindergarten through the college/university level still…

  15. 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…

  16. Closing the Achievement Gap with Curriculum Enrichment and Differentiation: One School's Story

    ERIC Educational Resources Information Center

    Beecher, Margaret; Sweeny, Sheelah M.

    2008-01-01

    This article summarizes a unique approach to reducing the achievement gap that strategically blended differentiated curriculum with schoolwide enrichment teaching and learning. The theories of enrichment and instructional differentiation were translated into practice in an elementary school that had previously embraced a remedial paradigm. This…

  17. 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…

  18. Prospective Teachers from Urban Environments Examine Causes of the Achievement Gap in the United States

    ERIC Educational Resources Information Center

    Morales, Erik E.

    2016-01-01

    This study analyzes the educational achievement gap between low and high socioeconomic students from the perspective of sixty-two prospective teachers in an undergraduate educational foundations course at a public majority minority urban university in the northeastern United States. The majority of these college students come from, and plan to…

  19. 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 Intervention…

  20. 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…

  1. 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…

  2. Beating the Odds: The Real Challenges behind the Math Achievement Gap--And What High-Achieving Schools Can Teach Us about How to Close It

    ERIC Educational Resources Information Center

    Goldberger, Susan

    2008-01-01

    One of the most persistent inequities in U.S. education is the gap in math achievement along income and race lines. Yet some secondary schools beat the odds, producing consistently strong math performance with students who likely would fail in traditional settings. This report advocates that the math achievement gap is not the result of poor and…

  3. 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.

  4. Narrow band gap and visible light-driven photocatalysis of V-doped Bi6Mo2O15 nanoparticles

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Qin, Chuanxiang; Huang, Yanlin; Wang, Yaorong; Qin, Lin; Seo, Hyo Jin

    2017-02-01

    Pure and V5+-doped Bi6Mo2O15 (3Bi2O3·2MoO3) photocatalysts were synthesized through electrospinning, followed by low-temperature heat treatment. The samples developed into nanoparticles with an average size of approximately 50 nm. The crystalline phases were verified via X-ray powder diffraction measurements (XRD). The surface properties of the photocatalysts were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses. The UV-vis spectra showed that V doping in Bi6Mo2O15 shifted the optical absorption from the UV region to the visible-light wavelength region. The energy of the band gap of Bi6Mo2O15 was reduced by V doping in the lattices. The photocatalytic activities of the pure and V-doped Bi6Mo2O15 were tested through photodegradation of rhodamine B (RhB) dye solutions under visible light irradiation. Results showed that 20 mol% V-doped Bi6Mo2O15 achieved efficient photocatalytic ability. RhB could be degraded by V-doped Bi6Mo2O15 in 2 h. The photocatalytic activities and mechanisms were discussed according to the characteristics of the crystal structure and the results of EIS and XPS measurements.

  5. Have Gender Gaps in Math Closed? Achievement, Teacher Perceptions, and Learning Behaviors across Two ECLS-K Cohorts

    ERIC Educational Resources Information Center

    Cimpian, Joseph R.; Lubienski, Sarah T.; Timmer, Jennifer D.; Makowski, Martha B.; Miller, Emily K.

    2016-01-01

    Studies using data from the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999 (ECLS-K:1999) revealed gender gaps in mathematics achievement and teacher perceptions. However, recent evidence suggests that gender gaps have closed on state tests, raising the question of whether such gaps are absent in the ECLS-K:2011 cohort.…

  6. 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.

  7. 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.

  8. Closing Achievement Gaps with a Utility-Value Intervention: Disentangling Race and Social Class

    PubMed Central

    Harackiewicz, Judith M.; Canning, Elizabeth A.; Tibbetts, Yoi; Priniski, Stacy J.; Hyde, Janet S.

    2015-01-01

    Many college students abandon their goal of completing a degree in STEM when confronted with challenging introductory-level science courses. In the U.S., this trend is more pronounced for underrepresented minority (URM) and first-generation (FG) students, and contributes to persisting racial and social-class achievement gaps in higher education. Previous intervention studies have focused exclusively on race or social class, but have not examined how the two may be confounded and interact. This research therefore investigates the independent and interactive effects of race and social class as moderators of an intervention designed to promote performance, measured by grade in the course. In a double-blind randomized experiment conducted over four semesters of an introductory biology course (N = 1040), we tested the effectiveness of a utility-value intervention in which students wrote about the personal relevance of course material. The utility-value intervention was successful in reducing the achievement gap for FG-URM students by 61%: the performance gap for FG-URM students, relative to CG-Majority students, was large in the control condition, .84 grade points (d = .98), and the treatment effect for FG-URM students was .51 grade points (d = 0.55). The UV intervention helped students from all groups find utility value in the course content, and mediation analyses showed that the process of writing about utility value was particularly powerful for FG-URM students. Results highlight the importance of examining the independent and interactive effects of race and social class when evaluating interventions to close achievement gaps and the mechanisms through which they may operate. PMID:26524001

  9. 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…

  10. 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…

  11. 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…

  12. 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 analytic…

  13. 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.

  14. Narrowing of band gap and effective charge carrier separation in oxygen deficient TiO2 nanotubes with improved visible light photocatalytic activity.

    PubMed

    Choudhury, Biswajit; Bayan, Sayan; Choudhury, Amarjyoti; Chakraborty, Purushottam

    2016-03-01

    Oxygen vacancies are introduced into hydrothermally processed TiO2 nanotube by vacuum calcination. Formation of oxygen vacancies modifies the local coordination in TiO2 as evident from Raman spectroscopy and secondary ion mass spectrometry (SIMS) results. The surface area is increased from 172.5m(2)/g in pure to 405.1m(2)/g in defective TiO2 nanotube. The mid-band gap electronic states created by oxygen vacancies are mostly responsible for the effective narrowing of band gap. Charge carrier separation is sufficiently prolonged as the charged oxygen defect states inhibit facile carrier recombination. With high surface area, narrowed band gap and separated charge carriers defective TiO2 nanotube is a suitable candidate in the photodegradation of methylene blue (MB) and phenol under visible light illumination. Photosensitized electron transfer from MB to the conduction band of TiO2 and the photodegradation of MB is facilitated in presence of high density of oxygen vacancies. Unlike MB, phenol absorbs in the UV region and does not easily excited under visible light. Phenol shows activity under visible light by forming charge transfer complex with TiO2. Defect trapped carriers become available at the phenol-TiO2 interface and finally interact with phenol molecule and degrade it.

  15. 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.

  16. 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.

  17. 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.

  18. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    NASA Astrophysics Data System (ADS)

    Agrawal, B. P.; Ghosh, P. K.

    2017-02-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  19. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    NASA Astrophysics Data System (ADS)

    Agrawal, B. P.; Ghosh, P. K.

    2017-03-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  20. 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.

  1. Daily online testing in large classes: boosting college performance while reducing achievement gaps.

    PubMed

    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.

  2. 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.

  3. 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.

  4. Reading Achievement Gaps, Correlates, and Moderators of Early Reading Achievement: Evidence from the Early Childhood Longitudinal Study (ECLS) Kindergarten to First Grade Sample

    ERIC Educational Resources Information Center

    Chatterji, Madhabi

    2006-01-01

    This study estimated reading achievement gaps in different ethnic, gender, and socioeconomic groups of 1st graders in the U.S. compared with specific reference groups and identified statistically significant correlates and moderators of early reading achievement. A subset of 2,296 students nested in 184 schools from the Early Childhood…

  5. Effects of electron-impurity scattering on density of states in silicene: Impurity bands and band-gap narrowing

    NASA Astrophysics Data System (ADS)

    Liu, S. Y.; Zeng, Y. C.; Lei, X. L.

    2016-12-01

    Considering the interband correlation, we present a generalized multiple-scattering approach of Green's function to investigate the effects of electron-impurity scattering on the density of states in silicene at zero temperature. The reduction of energy gaps in the case of relatively high chemical potential and the transformation of split-off impurity bands into band tails for low chemical potential are found. The dependency of optical conductivity on the impurity concentration is also discussed for frequency within the terahertz regime.

  6. Band-gap narrowing and magnetic behavior of Ni-doped Ba(Ti0.875Ce0.125)O3 thin films

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    Band-gap narrowing and magnetic effects have been observed in a Ni-doped Ba(Ti0.875Ce0.125)O3 (BTC) thin film. Structural characterizations and microstructural analysis show that the as-prepared Ba(Ti0.75Ce0.125Ni0.125)O3-δ (BTCN) thin film exhibits a cubic perovskite structure with an average grain size of 25 nm. The Ce doping at the Ti-site results in an increasing perovskite volume to favour an O-vacancy-stabilized Ni2+ substitution. Raman spectroscopy, however, shows the cubic symmetry of crystalline structures is locally lowered by the presence of dopants, significantly deviating from the ideal Pm3m space group. Moreover, BTCN presents a narrowed band-gap, much smaller than that of BaTiO3 and BTC, due 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. Also, magnetic enhancement driven by co-doping has been confirmed in the films, which mainly stems from the exchange interaction of Ni2+ ions via an electron trapped in a bridging oxygen vacancy. These findings may open an avenue to discover and design optimal perovskite compounds for solar-energy devices and information storage.

  7. 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.

  8. 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…

  9. Are Early Childhood Disparities Narrowing? The Changing Nature of Early Childhood and Its Link to Narrowing School-Entry Achievement Gaps

    ERIC Educational Resources Information Center

    Bassok, Daphna; Finch, Jenna; Lee, RaeHyuck; Reardon, Sean F.; Waldfogel, Jane

    2016-01-01

    To date, no studies have documented how much early childhood experiences have changed over time. In the current study, researchers use two large, nationally representative datasets of kindergarten entrants to document the following: (1) How have children's early childhood experiences changed between 1998 and 2010?; (2) To what extent have…

  10. 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…

  11. 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…

  12. 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

  13. Design of narrow-gap TiO2: a passivated codoping approach for enhanced photoelectrochemical activity.

    PubMed

    Gai, Yanqin; Li, Jingbo; Li, Shu-Shen; Xia, Jian-Bai; Wei, Su-Huai

    2009-01-23

    To improve the photoelectrochemical activity of TiO2 for hydrogen production through water splitting, the band edges of TiO2 should be tailored to match with visible light absorption and the hydrogen or oxygen production levels. By analyzing the band structure of TiO2 and the chemical potentials of the dopants, we propose that the band edges of TiO2 can be modified by passivated codopants such as (Mo+C) to shift the valence band edge up significantly, while leaving the conduction band edge almost unchanged, thus satisfying the stringent requirements. The design principle for the band-edge modification should be applicable to other wide-band-gap semiconductors.

  14. 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

  15. Generating evidence to narrow the treatment gap for mental disorders in sub-Saharan Africa: rationale, overview and methods of AFFIRM.

    PubMed

    Lund, C; Alem, A; Schneider, M; Hanlon, C; Ahrens, J; Bandawe, C; Bass, J; Bhana, A; Burns, J; Chibanda, D; Cowan, F; Davies, T; Dewey, M; Fekadu, A; Freeman, M; Honikman, S; Joska, J; Kagee, A; Mayston, R; Medhin, G; Musisi, S; Myer, L; Ntulo, T; Nyatsanza, M; Ofori-Atta, A; Petersen, I; Phakathi, S; Prince, M; Shibre, T; Stein, D J; Swartz, L; Thornicroft, G; Tomlinson, M; Wissow, L; Susser, E

    2015-06-01

    There is limited evidence on the acceptability, feasibility and cost-effectiveness of task-sharing interventions to narrow the treatment gap for mental disorders in sub-Saharan Africa. The purpose of this article is to describe the rationale, aims and methods of the Africa Focus on Intervention Research for Mental health (AFFIRM) collaborative research hub. AFFIRM is investigating strategies for narrowing the treatment gap for mental disorders in sub-Saharan Africa in four areas. First, it is assessing the feasibility, acceptability and cost-effectiveness of task-sharing interventions by conducting randomised controlled trials in Ethiopia and South Africa. The AFFIRM Task-sharing for the Care of Severe mental disorders (TaSCS) trial in Ethiopia aims to determine the acceptability, affordability, effectiveness and sustainability of mental health care for people with severe mental disorder delivered by trained and supervised non-specialist, primary health care workers compared with an existing psychiatric nurse-led service. The AFFIRM trial in South Africa aims to determine the cost-effectiveness of a task-sharing counselling intervention for maternal depression, delivered by non-specialist community health workers, and to examine factors influencing the implementation of the intervention and future scale up. Second, AFFIRM is building individual and institutional capacity for intervention research in sub-Saharan Africa by providing fellowship and mentorship programmes for candidates in Ethiopia, Ghana, Malawi, Uganda and Zimbabwe. Each year five Fellowships are awarded (one to each country) to attend the MPhil in Public Mental Health, a joint postgraduate programme at the University of Cape Town and Stellenbosch University. AFFIRM also offers short courses in intervention research, and supports PhD students attached to the trials in Ethiopia and South Africa. Third, AFFIRM is collaborating with other regional National Institute of Mental Health funded hubs in Latin

  16. Mind the Gap: 20 Years of Progress and Retrenchment in School Funding and Achievement Gaps. Policy Information Report. ETS RR-16-15

    ERIC Educational Resources Information Center

    Baker, Bruce D.; Farrie, Danielle; Sciarra, David G.

    2016-01-01

    Although there has been significant progress in the long term, achievement gaps among the nation's students persist.Many factors have contributed to the disparities in outcomes, and societal changes can explain progress, or lack thereof, over the past few decades.This is well documented in the 2010 Educational Testing Service (ETS) report…

  17. 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.

  18. 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…

  19. 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…

  20. 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 with high…

  1. 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…

  2. An Examination of Tri-Level Collaboration around Student Achievement Using the Gap Analysis Approach: Teacher Factors

    ERIC Educational Resources Information Center

    Carruthers, Anthony Steven

    2013-01-01

    Using the Gap Analysis problem-solving framework (Clark & Estes, 2008), this project examined collaboration around student achievement in the Pasadena Unified School District (PUSD) from the teacher perspective. As part of a tri-level study, two other projects examined collaboration around student achievement in PUSD from the perspectives of…

  3. New insights into the band-gap narrowing of (N, P)-codoped TiO2 from hybrid density functional theory calculations.

    PubMed

    Long, Run; English, Niall J

    2011-10-04

    The electronic properties of anatase-TiO(2) codoped by N and P at different concentrations have been investigated via generalized Kohn-Sham theory with the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional for exchange-correlation in the context of density functional theory. At high doping concentrations, we find that the high photocatalytic activity of (N, P)-codoped anatase TiO(2) vis-à-vis the N-monodoped case can be rationalized by a double-hole-mediated coupling mechanism [Yin et al., Phys. Rev. Lett. 2011, 106, 066801] via the formation of an effective N-P bond. On the other hand, Ti(3+) and Ti(4+) ions' spin double-exchange results in more substantial gap narrowing for larger separations between N and P atoms. At low doping concentrations, double-hole-coupling is dominant, regardless of the N-P distance.

  4. Photocurrent response wavelength up to 1.1 μm from photovoltaic cells based on narrow-band-gap conjugated polymer and fullerene derivative

    NASA Astrophysics Data System (ADS)

    Xia, Yangjun; Wang, Li; Deng, Xianyu; Li, Dongyun; Zhu, Xuhui; Cao, Yong

    2006-08-01

    An extremely narrow-band-gap conjugated polymer poly(5,7-bis(4-decanyl-2-thienyl)thieno[3,4-b]diathiazole-thiophene-2,5) (PDDTT) (Eg≈1.01eV) was synthesized by Stille coupling reaction, which absorbs the light from 330-1220nm in solid thin film and shows good solution processibility. The polymeric photovoltaic cells based on PDDTT/[6,6]-phenyl-C61-butyric acid methyl ester blend show the short circuit density of 0.83mA/cm2, open current voltage of 0.35V, and photocurrent spectra response from 330to1100nm under AM 1.5 simulator (100mW/cm2).

  5. 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

  6. Role of Leadership in Narrowing the Gap between Science and Practice: Improving Treatment Outcomes at the Systems Level.

    PubMed

    Saeed, Sy Atezaz; Bloch, Richard M; Silver, Stuart

    2015-09-01

    It's been well documented that health care does not reliably transfer what we know from science into clinical practice. As a result, Americans do not always receive the care suggested by the scientific evidence. Despite the best intentions of a dedicated and skilled healthcare workforce, this can often lead to poor clinical outcomes. As research and technology rapidly advance, this gap between science and practice appears to be widening. There is an increasing public concern about a lack of access to appropriate treatment, pervasiveness of unsafe practices, and wasteful uses of precious health care resources leading to suboptimum treatment outcomes. Leadership has a critical role in creating and sustaining the environment that supports health services for individuals and populations that increase the likelihood of desired health outcomes and are consistent with current professional knowledge. Leadership has some responsibility to improve outcomes by insuring effective use of evidence-based treatment guidelines; measurement-based care; knowledge and skills management; care coordination; and information technologies. This paper addresses leadership issues in these components of a system's ability to improve treatment outcomes.

  7. Improving low-temperature performance of infrared thin-film interference filters utilizing the intrinsic properties of IV-VI narrow-gap semiconductors.

    PubMed

    Li, Bin; Zhang, S; Jiang, J; Fan, B; Zhang, F

    2004-02-09

    Pb(1) (-x)Ge(x)Te is a pseudobinary alloy of IV-VI narrow-gap semiconductor, of which maximum refractive index corresponds to the ferroelectric phase transition. Since the temperature coefficient of refractive index can be tunable from negative to positive by changing the Ge composition, it is possible to utilize the intrinsic property in the fabrication of infrared thin-film interference filters. In this letter, we report a narrow-bandpass filter, in which Pb(0.94)Ge(0.06)Te was substituted for PbTe. It found that the low-temperature stability of the filter is obviously improved: in the temperature range of 80-300K, the shift of center wavelength with temperature is reduced from 0.48nm.K(-1) to 0.23nm K(-1); furthermore, the peak transmittance of filter fabricated with Pb(0.94)Ge(0.06)Te is ~3% over that fabricated with PbTe.

  8. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap.

    PubMed

    Großkinsky, Dominik K; Svensgaard, Jesper; Christensen, Svend; Roitsch, Thomas

    2015-09-01

    Plants are affected by complex genome×environment×management interactions which determine phenotypic plasticity as a result of the variability of genetic components. Whereas great advances have been made in the cost-efficient and high-throughput analyses of genetic information and non-invasive phenotyping, the large-scale analyses of the underlying physiological mechanisms lag behind. The external phenotype is determined by the sum of the complex interactions of metabolic pathways and intracellular regulatory networks that is reflected in an internal, physiological, and biochemical phenotype. These various scales of dynamic physiological responses need to be considered, and genotyping and external phenotyping should be linked to the physiology at the cellular and tissue level. A high-dimensional physiological phenotyping across scales is needed that integrates the precise characterization of the internal phenotype into high-throughput phenotyping of whole plants and canopies. By this means, complex traits can be broken down into individual components of physiological traits. Since the higher resolution of physiological phenotyping by 'wet chemistry' is inherently limited in throughput, high-throughput non-invasive phenotyping needs to be validated and verified across scales to be used as proxy for the underlying processes. Armed with this interdisciplinary and multidimensional phenomics approach, plant physiology, non-invasive phenotyping, and functional genomics will complement each other, ultimately enabling the in silico assessment of responses under defined environments with advanced crop models. This will allow generation of robust physiological predictors also for complex traits to bridge the knowledge gap between genotype and phenotype for applications in breeding, precision farming, and basic research.

  9. Role of fractures in weathering of solid rocks: narrowing the gap between laboratory and field weathering rates

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando A. L.; Alencoão, Ana M. P.

    2006-01-01

    A weathering study of a fractured environment composed of granites and metasediments was conducted in Trás-os-Montes and Alto Douro (north of Portugal) and covered the hydrographic basin of Sordo river. Within the basin, a number of perennial springs were monitored for discharge rate, which allowed for the estimation of annual recharges. A small area of the basin was characterized for parameters such as hydraulic conductivity and effective porosity, which, in combination with the previously calculated recharges, allowed for the calculation of a fracture surface area. The monitored springs were also sampled and analyzed for major inorganic compounds, and using a mole balance model the chemistry of the water samples was explained by weathering to kaolinite of albite-oligoclase plus biotite (granites) or of albite plus chlorite (metasediments). The number of moles of dissolved primary minerals (e.g. albite) could be calculated using this method. These mass transfers were then multiplied by the spring's median discharge rate and divided by the fracture surface area to obtain a weathering rate. Another weathering rate was determined, but using a BET surface area as normalizing factor. Comparing both rates with a representative record of laboratory as well as of field-based weathering rates, it has been noted that rates normalized by the BET were, as expected, similar to commonly reported field-based rates, whereas rates normalized by the fracture surface area were unexpectedly relatively close to laboratory rates (one order of magnitude smaller). The monitored springs are of the fracture artesian type, which means that water emerging at the spring site flowed preferentially through joints and fractures and that weathering took place predominantly at their walls. Consequently, it was concluded that the most realistic weathering rates are those normalized by the fracture surface area, and as a corollary that the gap between laboratory and field weathering rates might not

  10. Birth Cohort and the Black-White Achievement Gap: The Roles of Access and Health Soon after Birth. NBER Working Paper No. 15078

    ERIC Educational Resources Information Center

    Chay, Kenneth Y.; Guryan, Jonathan; Bhashkar, Mazumder

    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)…

  11. 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…

  12. The influence of narrow optical gap silver oxide on zinc oxide nanoparticles produced by microwave-assisted colloidal synthesis: photocatalytic studies

    NASA Astrophysics Data System (ADS)

    Prakoso, S. P.; Paramarta, V.; Tju, H.; Taufik, A.; Saleh, R.

    2016-11-01

    This paper reports a photocatalytic study on wide band gap zinc oxide (ZnO) incorporated by narrow band gap silver oxide (Ag2O), namely Ag2O/ZnO nanocomposites, which were prepared by colloidal synthesis with microwave supports. The Ag2O/ZnO nanocomposites were prepared with three different molar ratios (MR) of Ag2O to ZnO (MR: 0.25, 0.5 and 0.75). In order to confirm qualitatively the concentration ratio of Ag2O in ZnO, crystal phase intensity ratio was executed by peak indexing from x-ray diffraction. The Ag2O/ZnO nanocomposites properties were further investigated using diffuse reflectance spectroscopy. The nanocomposites were tested for the degradation of organic dyes solutions under visible and UV light irradiations. The photocatalytic activity of Ag2O/ZnO nanocomposites under visible light increased with increasing molar ratio of Ag2O to ZnO, while the opposite trends observed under UV light irradiation. The improvement of photoabsorption together with photocatalytic activities might be suspected due to the p-n heterojunction structure in Ag2O/ZnO nanocomposites. The corresponding mechanism will be discussed in detail.

  13. Gaps Between Aims and Achievements in Therapeutic Modification of Neuronal Damage ("Neuroprotection").

    PubMed

    Wiendl, Heinz; Elger, Christian; Förstl, Hans; Hartung, Hans-Peter; Oertel, Wolfgang; Reichmann, Heinz; Schwab, Stefan

    2015-04-01

    The term "neuroprotection" is often misused, overused, or misunderstood. A reasonable definition of neuroprotection refers to the preservation of "neuronal structure and/or function." Although our knowledge about the cellular and molecular mechanisms of neurodegeneration has expanded, experimental systems and animal models that mimic the process or allow translation into clinical success remain limited. This editorial discusses reasons for this gap and strategies to close it. Experimental models can only mirror certain aspects of disease mechanisms in humans. Therefore, findings in these models need to be linked with patient data to improve real-life relevance. Successful neuroprotection depends on finding the right "window of opportunity" which varies from very short (stroke) to very long (Alzheimer's disease), necessitating the need to focus on strategies for very early disease recognition. This need challenges the strategies to be chosen, trial approaches and methodologies, and the allocation of resources. Additionally, outcome measures are often not well suited to assess neuroprotection. To this end, surrogate measures, including biomarkers, are useful endpoints to demonstrate evidence of target directed therapeutic utility. Finally, studies have shown that neuroprotection is not likely to succeed when targeting only one pathway. These obstacles have reduced the level of enthusiasm for neuroprotection in certain disease areas (e.g., stroke). Academia, industry, regulatory authorities, funding agencies and patient organizations have to cooperate to a greater extent in order to overcome these impediments and to encourage nonclassical concepts. These concepts will be interdisciplinary in order to achieve meaningful disease modification.

  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 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.

  15. 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

  16. 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…

  17. High-Stakes Tests: Comparative Study Examining the Impact on the Achievement Gap that Causes Minority Students Continued Failure

    ERIC Educational Resources Information Center

    Taylor-Smith, Carol J.

    2011-01-01

    The purpose of this comparative qualitative study examined the impact of the achievement gap on the lack of highly qualified teachers instructing African American students consistently from K-12th grades and its effects on high-stakes testing. In addition, the study examined teacher perceptions that could also be contributing factors of the…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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 developing…

  4. 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,…

  5. 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.…

  6. Comparison of microstructure and mechanical properties of ultra-narrow gap laser and gas-metal-arc welded S960 high strength steel

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Li, Lin; Dong, Shiyun; Crowther, Dave; Thompson, Alan

    2017-04-01

    The microstructural characteristics and mechanical properties, including micro-hardness, tensile properties, three-point bending properties and Charpy impact toughness at different test temperatures of 8 mm thick S960 high strength steel plates were investigated following their joining by multi-pass ultra-narrow gap laser welding (NGLW) and gas metal arc welding (GMAW) techniques. It was found that the microstructure in the fusion zone (FZ) for the ultra-NGLW joint was predominantly martensite mixed with some tempered martensite, while the FZ for the GMAW joint was mainly consisted of ferrite with some martensite. The strength of the ultra-NGLW specimens was comparable to that of the base material (BM), with all welded specimens failed in the BM in the tensile tests. The tensile strength of the GMAW specimens was reduced approximately by 100 MPa when compared with the base material by a broad and soft heat affected zone (HAZ) with failure located in the soft HAZ. Both the ultra-NGLW and GMAW specimens performed well in three-point bending tests. The GMAW joints exhibited better impact toughness than the ultra-NGLW joints.

  7. 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.

  8. Gap Analysis for Chinese Drug Control Institutes to Achieve the Standards of World Health Organization Medicine Prequalification.

    PubMed

    Mao, Xin; Yang, Yue

    2017-02-01

    The study aims to explore the challenges and the gaps faced by Chinese Drug Control Institutes in achieving the standards of World Health Organization (WHO) Medicine Prequalification. The study was undertaken with 6 Provincial Drug Control Institutes in China from November 2012 to November 2013. The study assessed key elements required to comply with WHO Good Practices for Pharmaceutical Quality Control Laboratories (GPPQCL). For GPPQCL, the study found gaps in quality management system, control of documentation, data-processing equipment, premises and equipment, contracts, reagents (water), reference substances and reference materials, calibration, verification of performance and qualification of equipment, instruments and other devices, analytical worksheet, evaluation of test results, personnel, and validation of analytical procedures. The study indicates that gaps are attributed to differences between the standards of Chinese Accreditation Standards and WHO-GPPQCL.

  9. 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)

  10. Closing the Racial Achievement Gap: Learning from Florida's Reforms. Backgrounder. No. 2468

    ERIC Educational Resources Information Center

    Ladner, Matthew; Burke, Lindsey M.

    2010-01-01

    An education gap between white students and their black and Hispanic peers is something to which most Americans have become accustomed. But this racial division of education--and hence of prospects for the future--is nothing less than tragic. The good news is that the racial divide in learning is a problem that can be fixed. Of course, it can only…

  11. 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…

  12. 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…

  13. 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…

  14. Reading Attainment in Irish Primary Schools--A Progressive Achievement Gap?

    ERIC Educational Resources Information Center

    Martin, M. O.

    Approximately 4,000 children took part in a study of the reading attainments of children from different social-class backgrounds in Irish primary schools to find out if the progessive reading gap between children from different home backgrounds that has been observed in other countries could also be found in Irish school children. Tests were…

  15. 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…

  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. 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…

  18. The Role of Schools in the English Language Learner Achievement Gap

    ERIC Educational Resources Information Center

    Fry, Richard

    2008-01-01

    Students designated as English language learners (ELL) tend to go to public schools that have low standardized test scores. However, these low levels of assessed proficiency are not solely attributable to poor achievement by ELL students. These same schools report poor achievement by other major student groups as well, and have a set of…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  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…

  6. 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…

  7. Influence of Filament and Substrate Temperatures on Structural and Optoelectronic Properties of Narrow Gap a-SiGe:H Alloys Deposited by Hot-Wire CVD: Preprint

    SciTech Connect

    Xu, Y.; Nelson, B. P.; Gedvilas, L. M.; Reedy, R. C.; Williamson, D. L.

    2003-04-01

    We have found that narrow-bandgap--1.25< Tauc Gap< 1.50 eV--amorphous silicon germanium (a-SiGe:H) alloys grown by hot-wire chemical vapor deposition (CVD) can be improved by lowering both substrate and filament temperatures. We systematically studied films deposited using a one-tungsten filament, decreasing filament temperature (Tf) from our standard temperature of 2150ý down to 1750ýC, and fixing all other deposition parameters. By decreasing Tf at the fixed substrate temperature (Ts) of 180ýC, the Ge-H bonding increases, whereas the Si-H2 bonding is eliminated. Films with higher Ge-H bonding and less Si-H2 have improved photoconductivity. For the series of films deposited using the same germane gas fraction at 35%, the energy where the optical absorption is 1x104 (E04) drops from 1.54 to 1.41 eV with decreasing Tf. This is mainly due to the combination of an increasing Ge solid fraction (x) in the film, and an improved homogeneity and compactness due to significant reduction of microvoids, which was confirmed by small-angle X-ray scattering (SAXS). We also studied a series of films grown by decreasing the Ts from our previous standard temperature of 350ýC down to 125ýC, fixing all other deposition parameters including Tf at 1800ýC. By decreasing Ts, both the total hydrogen content and the Ge-H bonding increased, but the Si-H2 bonding is not measurable in the Ts range of 180ý-300ýC. The E04 increases from 1.40 to 1.51 eV as Ts decreased from 350ý to 125ýC, mainly due to the increased total hydrogen content. At the same time, the photo-to-dark conductivity ratio increases almost three orders of magnitude over this range of Ts.

  8. 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.

  9. 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…

  10. 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…

  11. Teachers' Perceptions of Students' Mathematics Proficiency May Exacerbate Early Gender Gaps in Achievement

    ERIC Educational Resources Information Center

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

    2014-01-01

    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'…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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 in…

  18. 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…

  19. The Effects of the Achievement Gap on Students Formally Identified as Gifted. Does Giftedness Prevail?

    ERIC Educational Resources Information Center

    Chism, Dwayne T.

    2012-01-01

    This study shows that minority students who, based upon a standardized test, have shown a high academic performance capability have a readiness for rigorous courses in high school and can sustain high academic achievement over time when compared to non-minority peers. Therefore, the on-going question for many educators needs to be why doesn't…

  20. 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…

  1. 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…

  2. 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…

  3. Student to Teacher Racial/Ethnic Ratios as Contributors to Regional Achievement Gaps, 1999-2008

    ERIC Educational Resources Information Center

    Hays, James M.

    2011-01-01

    With the advent of No Child Left Behind legislation in 2002 and its mandates for annual yearly progress for all students, many districts and schools in Texas have had difficulty elevating African American and Hispanic students' scores. The current study examined these students' achievement on the annual Texas high-stakes measure as a function of a…

  4. Using Factors of Socioeconomic Status, Family Support, and Academic Preparation to Explain the Black-White Gap in Mathematics Achievement and Participation

    ERIC Educational Resources Information Center

    Watson, Charity Noel

    2012-01-01

    The Black-White achievement and participation gap in mathematics is a major concern for educators in America. In order to understand why these gaps exist and have continued to exist over the years, it is important to identify some of the factors that may contribute to them. However, one of the limitations in identifying factors that influence the…

  5. Changes in Math Achievement Gaps under the Era of NNCLB: Between Different Immigrant Student Groups and Native-Born White Americans

    ERIC Educational Resources Information Center

    Jeon, Sue Bin

    2010-01-01

    Previous comparisons of the gaps in educational achievement between various minority groups (non-White, non-English-speaking, low income) and their counterparts (White, English-speaking, middle income) have tended to disregard the immigrant status of the minority students. In this study, I investigated these gaps within and between immigrant…

  6. The Politics of Achievement Gaps: U.S. Public Opinion on Race-Based and Wealth-Based Differences in Test Scores

    ERIC Educational Resources Information Center

    Valant, Jon; Newark, Daniel A.

    2016-01-01

    For decades, researchers have documented large differences in average test scores between minority and White students and between poor and wealthy students. These gaps are a focal point of reformers' and policymakers' efforts to address educational inequities. However, the U.S. public's views on achievement gaps have received little attention from…

  7. 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.

  8. Examining the Black-White achievement gap among low-income children using the NICHD study of early child care and youth development.

    PubMed

    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 4½ 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 quality was a stronger predictor for Black than White children. In addition, the achievement gap was detected as young as 3 years of age. Taken together, the findings suggest that reducing the Black-White achievement gap may require early intervention to reduce race gaps in home and school experiences during the infant and toddler years as well as during the preschool and school years.

  9. Parental Resources, Schooling Achievements, and Gender Schooling Gaps: Evidence of Change over 25 years in Rural Guatemala

    PubMed Central

    Maluccio, John A.; Behrman, Jere R.; Hoddinott, John; Murphy, Alexis; Ramakrishnan, Usha

    2013-01-01

    We use village census data and linear regression models to examine changes between 1975 and 2002 in the associations of parental resources with boys' and girls' schooling in four rural Guatemalan villages. Levels of schooling in 1975 were universally low for children 7–17 years. Large increases in schooling achievements occurred between 1975 and 2002. By 2002, schooling levels were comparable for younger boys and girls (7–12 years, N = 3,525) and favored older boys compared to older girls (13–17 years, N = 2,440) by about 0.5 grades. The associations of household standard of living and maternal schooling with schooling among girls diminished over time and became more comparable with these associations among boys, and the associations of household standard of living with schooling among older boys declined and became more comparable with these associations among girls. Thus, as increased social investments reduce the costs of schooling or increase the supply and quality of schooling to families, the magnitudes of the associations between parental resources and children's schooling decline and become more gender equitable at all ages. However, our results show that older boys may benefit more than older girls from social investments in schooling. These changes suggest potential needs to monitor gender gaps in schooling retention among older children, to insure gender equitable access to social investments in schooling, and to encourage parents to invest in schooling as joint measures to achieve greater schooling achievements of girls and boys. PMID:23888089

  10. 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…

  11. 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.

  12. 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…

  13. 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…

  14. 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…

  15. 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…

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

    ERIC Educational Resources Information Center

    Center on Education Policy, 2011

    2011-01-01

    This paper profiles Colorado's test score trends through 2008-09. In 2003, the mean scale score on the state 4th grade reading test was 598 for non-Title I students and 558 for Title I students. In 2009, the mean scale score in 4th grade reading was 599 for non-Title I students and 556 for Title I students. Between 2003 and 2009, the mean scale…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  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? 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…

  11. 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…

  12. Synthesis of narrow band gap (V 2O 5) x-(TiO 2) 1- x nano-structured layers via micro arc oxidation

    NASA Astrophysics Data System (ADS)

    Bayati, M. R.; Moshfegh, A. Z.; Golestani-Fard, F.

    2010-02-01

    V 2O 5-TiO 2 layers with a sheet-like morphology were synthesized by micro arc oxidation process for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). Phase structure and chemical composition of the layers were also studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. It was revealed that the composite layers had a sheet-like structure average thickness of which was about 100 nm depending on the applied voltage. The layers consisted of anatase, rutile, and vanadium pentoxide phases fractions of which varied with the applied voltage. The optical properties of the layers were also examined employing a UV-vis spectrophotometer. It was found that the absorption edge of the grown composite layers shifted toward the visible wavelengths when compared to MAO-synthesized pure titania layers. The band gap energy of the composite layers was calculated as 2.58 eV. Furthermore, photo-catalytic performance of the layers was examined by measuring the decomposition rate of methylene blue under ultraviolet and visible irradiations. The results demonstrated that about 90% and 68% of methylene blue solution was decomposed after 120 min ultraviolet and visible irradiations over the composite layers, respectively.

  13. Postindustrial Capitalism and the Problems with Bourdieu's Social and Cultural Capital in Understanding the Black/White Achievement Gap in the United States and United Kingdom

    ERIC Educational Resources Information Center

    Mocombe, Paul C.

    2015-01-01

    This hermeneutical essay demonstrates why and how Pierre Bourdieu's social reproduction theory is neither an adequate explanation for understanding praxis nor the Black/White academic achievement gap in contemporary postindustrial economies like that of the United States and the United Kingdom. The underlining hypothesis of the work is that the…

  14. Who Is Ahead and Who Is Behind? Gaps in School Readiness and Student Achievement in the Early Grades for California's Children. Technical Report

    ERIC Educational Resources Information Center

    Cannon, Jill S.; Karoly, Lynn A.

    2007-01-01

    To evaluate the adequacy and efficiency of preschool education in California, the RAND Corporation has undertaken the California Preschool Study to improve understanding of achievement gaps in the early elementary grades, the adequacy of preschool education currently given, and what efficiencies or additional resources might be brought to bear in…

  15. A Hierarchical Examination of the Immigrant Achievement Gap: The Additional Explanatory Power of Nationality and Educational Selectivity over Traditional Explorations of Race and Socioeconomic Status

    ERIC Educational Resources Information Center

    Simms, Kathryn

    2012-01-01

    This study compared immigrant and nonimmigrant educational achievement (i.e., the immigrant gap) in math by reexamining the explanatory power of race and socioeconomic status (SES)--two variables, perhaps, most commonly considered in educational research. Four research questions were explored through growth curve modeling, factor analysis, and…

  16. The Effects of the Implementation of NCLB on the Achievement Gap between African American and White Students in Georgia Middle Schools

    ERIC Educational Resources Information Center

    Benson, Stacey L.

    2010-01-01

    This study examined the relationship between the implementation of No Child Left Behind and the achievement gap between African American and white students' eighth-grade math scores on the yearly-standardized test (Criterion Referenced Competency Test--CRCT) in Georgia. A descriptive research design was utilized to examine data obtained from the…

  17. Book Probes Scoring Gaps Tied to Race

    ERIC Educational Resources Information Center

    Viadero, Debra

    2009-01-01

    A recent book assembles a collection of studies on one of the great mysteries of contemporary American education: Why did national progress in narrowing the achievement gap separating African-American and white students stall from the late 1980s until 2004? "Steady Gains and Stalled Progress," published by the Russell Sage Foundation of New York…

  18. Closing the science achievement gap for ninth grade English learners through standards- and inquiry-based science instruction

    NASA Astrophysics Data System (ADS)

    Estrada, Myrna Hipol

    In light of the need to close the achievement gap among our culturally and linguistically diverse students, more specifically the Hispanics and the Hispanic English Learners (ELs), the effects of teacher professional development (2 year PD vs. 1 Year PD vs. no PD) on the implementation of a standards-aligned and inquiry-based science curriculum program---the Integrated Coordinated Science for the 21st Century published by It's About Time, Inc. (ICS-IAT)---on the LAUSD ninth graders science scores were examined. Participants included 8,937 9th grade students (7,356 Hispanics). The primary outcome measurement was scaled scores from the California Standard Test (CST) in Integrated Coordinated Science (CST_ICS1). Correlations between California English Language Development Test (CELDT) component subscores (reading, listening and speaking) and CST scores were also examined. Results indicated that the science scores of the students of teachers who participated in two year PD were significantly higher compared to the scores of students of the one year PD group and the control group. The results show that all ethnic groups benefited from two years of teacher PD, except the African American group. Among Hispanics, students classified as IFEP, RFEP and EO gained from the teachers having two years of professional development. But the target population, ELs did not benefit from two years of teacher PD. The correlations between the CELDT and CST_ELA were much higher than the CELDT and CST_ICS1 correlations. This finding validates Abedi's claim (2004) that EL students are disadvantaged because of their language handicap on tests that have a greater language load. Two year PD participation significantly enhanced the accessibility of science to the ninth graders. The essential features in the PD were classroom simulation of all the activities identified in the storyboard with the actual and correct use of needed equipment and materials; creation and presentation of sample or model

  19. Computer-Based Drill and Practice in Arithmetic: Widening the Gap between High- and Low-Achieving Students.

    ERIC Educational Resources Information Center

    Hativa, Nira

    1988-01-01

    The differential effects of computer-assisted instruction for high-achieving and low-achieving students were examined for seven elementary students of varied background. Higher-achieving students were more able to adjust to the requirements of computer work and to derive benefit from it than were lower-achieving students. Implications for teaching…

  20. Principals and School Counselors: Separate Entities in Identifying Achievement Gaps in College Readiness for African American Students With Disabilities

    ERIC Educational Resources Information Center

    Roberts, Laura A.; Bouknight, Tamisha M.

    2015-01-01

    This case illustrates an example of how one school relied solely on aggregate data and failed to address the college readiness needs of African American students with disabilities. However, the way in which the school counselor identified this opportunity gap may not have been the most ethical approach, and now she is faced with a dilemma. This…

  1. Experimental evidence of the kinetic performance achievable with columns packed with new 1.9μm fully porous particles of narrow particle size distribution.

    PubMed

    Ismail, Omar H; Catani, Martina; Pasti, Luisa; Cavazzini, Alberto; Ciogli, Alessia; Villani, Claudio; Kotoni, Dorina; Gasparrini, Francesco; Bell, David S

    2016-07-08

    Fully porous particles of narrow particle size distribution (nPSD) are now commercially available. In this paper, the kinetic performance of columns packed with these particles (1.9μm, 80Å pore size) has been investigated under typical reversed phase conditions by using a mixture of benzene derivatives as probes. The columns exhibited remarkably high efficiency (in the order of 300,000 theoretical plates per meter) and the possibility to be used at relatively high flow rates without loss of performance. These results contrast with previous studies on the same columns. Indeed we have found column efficiency comparable to that reported in previous work but, on the other hand, we could not observe the same dramatic loss of performance when columns were operated at high flow rates. The results presented in this paper, based on a set of six columns with different geometries (2.1 and 3.0 internal diameter×50, 75 and 100mm length), are not consistent with the previously proposed hypothesis that the unusually low intraparticle diffusion, which would characterize these particles, is the origin of the high efficiency of the columns. In a companion paper [1], a detailed investigation of the different terms leading to band broadening will be performed to point out the major contribution to plate height on nPSD columns.

  2. Achieving superwide-color-gamut display by using narrow-band green-emitting γ-AlON:Mn,Mg phosphor

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenichi; Fukunaga, Hiroshi; Izumi, Makoto; Takahashi, Kohsei; Xie, Rong-Jun; Hirosaki, Naoto

    2017-04-01

    The display backlight generated using sharp β-sialon:Eu (green) and K2SiF6:Mn (red) phosphors shows a very wide color gamut that mostly covers the whole National Television System Committee (NTSC) triangle. In this work, an alternative green phosphor is investigated to further improve the display color gamut. γ-AlON:Mn,Mg is a green phosphor that shows a shorter and narrower emission spectrum than sharp β-silaon:Eu. The display color gamut in the blue-green region is thus widened greatly by substituting γ-AlON:Mn,Mg for sharp β-sialon:Eu. The color gamut of displays with γ-AlON:Mn,Mg and K2SiF6:Mn exceeds 100% of the NTSC standard both in the CIE 1931 and the CIE 1976 color spaces. Furthermore, the white LEDs with γ-AlON:Mn,Mg have excellent stability that is comparable to those of LEDs with sharp β-sialon:Eu.

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  4. Closing the gaps in child health in the Pacific: An achievable goal in the next 20 years

    PubMed Central

    Duke, Trevor; Kado, Joseph H; Auto, James; Amini, James; Gilbert, Katherine

    2015-01-01

    It is not inconceivable that by 2035 the substantial gaps in child health across the Pacific can close significantly. Currently, Australia and New Zealand have child mortality rates of 5 and 6 per 1000 live births, respectively, while Pacific island developing nations have under 5 mortality rates ranging from 13 to 16 (Vanuatu, Fiji and Tonga) to 47 and 58 per 1000 live births (Kiribati and Papua New Guinea, respectively). However, these Pacific child mortality rates are falling, by an average of 1.4% per year since 1990, and more rapidly (1.9% per year) since 2000. Based on progress elsewhere, there is a need to (i) define the specific things needed to close the gaps in child health; (ii) be far more ambitious and hopeful than ever before; and (iii) form a new regional compact based on solidarity and interdependence. PMID:25586845

  5. Closing the gaps in child health in the Pacific: an achievable goal in the next 20 years.

    PubMed

    Duke, Trevor; Kado, Joseph H; Auto, James; Amini, James; Gilbert, Katherine

    2015-01-01

    It is not inconceivable that by 2035 the substantial gaps in child health across the Pacific can close significantly. Currently, Australia and New Zealand have child mortality rates of 5 and 6 per 1000 live births, respectively, while Pacific island developing nations have under 5 mortality rates ranging from 13 to 16 (Vanuatu, Fiji and Tonga) to 47 and 58 per 1000 live births (Kiribati and Papua New Guinea, respectively). However, these Pacific child mortality rates are falling, by an average of 1.4% per year since 1990, and more rapidly (1.9% per year) since 2000. Based on progress elsewhere, there is a need to (i) define the specific things needed to close the gaps in child health; (ii) be far more ambitious and hopeful than ever before; and (iii) form a new regional compact based on solidarity and interdependence.

  6. Mathematics Achievement Gaps between Suburban Students and Their Rural and Urban Peers Increase over Time. Issue Brief No. 52

    ERIC Educational Resources Information Center

    Graham, Suzanne E.; Provost, Lauren E.

    2012-01-01

    In this brief, authors Suzanne Graham and Lauren Provost examine whether attending a school in a rural, urban, or suburban community is related to children's mathematics achievement in kindergarten, and whether increases in mathematics achievement between kindergarten and eighth grade differ for children in rural, urban, and suburban schools. They…

  7. It Takes Leadership to Build a Village: A Portrait of a Public School Community That Is Closing the Achievement Gap

    ERIC Educational Resources Information Center

    MacCarthy, Julie

    2012-01-01

    This case study explored a high-achieving elementary school on Chicago's far South Side that fosters academic success for its African American students who come from predominately low-income homes. Tyler School serves a demographic group that historically underperforms. Yet multiple measures of evaluating student achievement indicate that Tyler is…

  8. Strengthening the Nation by Narrowing the Gap

    ERIC Educational Resources Information Center

    Handel, Stephen; Montoya, James

    2009-01-01

    A 2007 report by Jobs for the Future concluded that the United States "has miles to go to eliminate racial and ethnic disparities in degree production, strengthen the domestic workforce to meet demand for higher skills and knowledge, and remain internationally competitive." That the United States must educate more of its citizens for an…

  9. Narrowing the Gap between Readers and Books

    ERIC Educational Resources Information Center

    Hinton, KaaVonia; Dickinson, Gail K.

    2005-01-01

    So much hinges on putting the right book in a student's hands. Motivation to read is the foundation from which knowledge, reading competency, and comprehension grow. But how do we do it? Here, Hinton and Dickinson offer practical advice for how to reach kids through a partnership with library media specialists and a commitment to promoting books…

  10. Users` demands narrow PLC-DCS gap

    SciTech Connect

    La Fauci, J.

    1997-02-01

    Supervisory control and data acquisition (SCADA) operator interface (OI) software has propelled programmable logic controllers (PLCs) into areas where they can successfully compete with distributed control systems (DCSs) for many control applications. As a result, automation engineers are struggling to develop guidelines to help determine which is best for batch operations and other applications. There is no clear answer to this issue. There are, however, decision tools such as Kepner-Tregoe (K-T) that can be applied by engineers as a structured approach to decision analysis and system selection. Other factors such as business environment, pressure to reduce project cost, validation, and predicting new technology direction all play a critical role for engineers in choosing between a PLC- or DCS-based control system. Higher-level business issues, however, are seldom considered by engineers during control system selection. Engineers should try to better understand their company`s business objectives and mission statement and how company business direction may affect control system selection. For instance, the pharmaceutical industry can be broken up into the following five basic application groups: bulk chemicals, finishing, biotech, pilot plant, and utilities. Each has a unique set of functional and process-control requirements. Understanding needs and differences of these five basic application groups and applying the optimum control system solution will place the company in a more competitive position. A financial analysis should be one of the first steps in the control system evaluation process. This may include early agreement of contractual terms and conditions as well as a nondisclosure agreement. Other financial considerations may include requesting a financial report on the control system manufacturer or systems integrator that will be performing the work to determine its financial stability. 3 figs.

  11. Achievement Gaps: How Hispanic and White Students in Public Schools Perform in Mathematics and Reading on the National Assessment of Educational Progress. Statistical Analysis Report. NCES 2011-459

    ERIC Educational Resources Information Center

    Hemphill, F. Cadelle; Vanneman, Alan

    2011-01-01

    This report provides detailed information on the size of the achievement gaps between Hispanic and White public school students at the national and state levels and describes how those achievement gaps have changed over time. Additional information about race/ethnicity in NAEP is given in Appendix A. Most of the data in this report is derived from…

  12. The Black-White-Other Achievement Gap: Testing Theories of Academic Performance among Multiracial and Monoracial Adolescents

    ERIC Educational Resources Information Center

    Herman, Melissa R.

    2009-01-01

    The study presented here tested three theories of racial differences in academic performance among monoracial and multiracial high school students. These theories (status attainment, oppositional culture, and educational attitudes) were developed to explain differences in achievement among monoracial groups, but the study tested how the theories…

  13. Raising the Bar -- Closing the Gap. Recommendations for Improving the Academic Achievement of African-American Students in Missouri.

    ERIC Educational Resources Information Center

    Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

    In September 1996, the Missouri Commissioner of Education appointed a statewide task force on the Achievement of African-American Students. The findings of the state-level task force, the views of Missouri students, and the experience of successful educators all support the conclusion that the single most important nontangible element required to…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  15. Interpreting the Early Language Trajectories of Children from Low SES and Language Minority Homes: Implications for Closing Achievement Gaps

    PubMed Central

    Hoff, Erika

    2012-01-01

    On average, children from low SES homes and children from homes in which a language other than English is spoken have different language development trajectories than children from middle class, monolingual English-speaking homes. Children from low SES and language minority homes have unique linguistic strengths, but many reach school age with lower levels of English language skill than middle class, monolingual children. Because early differences in English oral language skill have consequences for academic achievement, low levels of English language skill constitute a deficit for children about to enter school in the U.S. Declaring all developmental trajectories to be equally valid would not change the robust relation between English oral language skills and academic achievement and would not help children with poor English skills to be successful in school. Remedies aimed at supporting the development of the English skills required for academic success need not and should not entail devaluing or diminishing children’s other language skills. PMID:22329382

  16. Interpreting the early language trajectories of children from low-SES and language minority homes: implications for closing achievement gaps.

    PubMed

    Hoff, Erika

    2013-01-01

    On average, children from low socioeconomic status (SES) homes and children from homes in which a language other than English is spoken have language development trajectories that are different from those of children from middle-class, monolingual English-speaking homes. Children from low-SES and language minority homes have unique linguistic strengths, but many reach school age with lower levels of English language skill than do middle-class, monolingual children. Because early differences in English oral language skill have consequences for academic achievement, low levels of English language skill constitute a deficit for children about to enter school in the United States. Declaring all developmental trajectories to be equally valid would not change the robust relation between English oral language skills and academic achievement and would not help children with poor English skills to be successful in school. Remedies aimed at supporting the development of the English skills required for academic success need not and should not entail devaluing or diminishing children's other language skills.

  17. The Effect of Reform-Based Science Teaching on SES-Associated Achievement Gap on PISA 2006: A Comparative Study of the United States and Taiwan

    NASA Astrophysics Data System (ADS)

    Tang, Nai-En

    The goal of this study is to examine how reform-based science teaching has been implemented and whether reform-based science teaching has promoted education equity through being available and beneficial for students from different socioeconomic status (SES) family backgrounds in the U.S. and Taiwan. No existing study used large-scale assessment to investigate the implementation and outcomes of the science reform movement in the U.S. and Taiwan. This study was developed to fill this gap using the Program of International Student Assessment (PISA) 2006 data including 5,611 students in the United States and 5995 students in Taiwan. A Latent Profile Analysis (LPA) was used to classify students into different science learning subgroups to understand how broadly reform-based science learning has been implemented in classrooms. The results showed that students in the U.S. had more opportunity to learn science through the reform-based learning activities than students in Taiwan. Latent Class Regression (LCR) and Structural Equation Modeling (SEM) were used for examining the availability of reform-based science teaching in both countries. The results showed that in the U.S., higher SES students had more opportunity to learn science reform-based learning activities. On the other hand, students' SES had no association with reform-based science learning in Taiwan. Regression Mixture Modeling and SEM were used to examine whether there was an association between reform-based science teaching and SES-associated achievement gaps. The results found no evidence to support the claim that reform-based science teaching helps to minimize SES-associated achievement gaps in both countries.

  18. Closing the social-class achievement gap: a difference-education intervention improves first-generation students' academic performance and all students' college transition.

    PubMed

    Stephens, Nicole M; Hamedani, MarYam G; Destin, Mesmin

    2014-04-01

    College students who do not have parents with 4-year degrees (first-generation students) earn lower grades and encounter more obstacles to success than do students who have at least one parent with a 4-year degree (continuing-generation students). In the study reported here, we tested a novel intervention designed to reduce this social-class achievement gap with a randomized controlled trial (N = 168). Using senior college students' real-life stories, we conducted a difference-education intervention with incoming students about how their diverse backgrounds can shape what they experience in college. Compared with a standard intervention that provided similar stories of college adjustment without highlighting students' different backgrounds, the difference-education intervention eliminated the social-class achievement gap by increasing first-generation students' tendency to seek out college resources (e.g., meeting with professors) and, in turn, improving their end-of-year grade point averages. The difference-education intervention also improved the college transition for all students on numerous psychosocial outcomes (e.g., mental health and engagement).

  19. Addressing Excellence Gaps in K-12 Education. Position Statement

    ERIC Educational Resources Information Center

    National Association for Gifted Children, 2015

    2015-01-01

    Since the passage of the No Child Left Behind Act in 2001, a major objective of federal and state education policy has been to narrow K-12 achievement gaps. This position statement notes that the available data suggest that the singular focus on the most struggling learners has resulted in meaningful progress in closing minimum-competency…

  20. A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs): An Achievement of Significant Morphological, Numerical and Functional Recovery

    PubMed Central

    Hirata, Maki; Nakajima, Nobuyuki; Saito, Kosuke; Hashimoto, Hiroyuki; Soeda, Shuichi; Uchiyama, Yoshiyasu; Watanabe, Masahiko

    2016-01-01

    Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs) to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34) and CD34-/45-/29+ (Sk-DN/29+) cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm) bridging an acellular conduit. After 8–12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells) were also observed. A significant tetanic tension recovery (over 90%) of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap) was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon) and functional (80% vs. 60% in tetanus) recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks) of recovery was observed in both groups with the expression of key factors (mRNA and protein levels), suggesting the paracrine effects to angiogenesis. These results suggested that the human Sk

  1. Closing the Pay Gap

    DTIC Science & Technology

    2000-10-01

    the pay gap has been narrowed, hut only to just under 10 percent. And current military compensation legislation does not close the gap until 2026. There...will continue to be a pay gap until 2026 unless the next administration and the next Congress provide more for pay above the 1999 legislated ramp- up...of .5 percent (one half of one percent) per year to attain pay equality . That means that soldiers, sailors, airmen, marines and Coast Guardsmen

  2. Gap Junctions

    PubMed Central

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  3. The Early College High School Model as a Means of Reducing or Eliminating the Achievement Gap for Students from Traditionally Underrepresented Populations

    ERIC Educational Resources Information Center

    Bramucci, Matthew G.

    2014-01-01

    The existence of a gap in academic performance between various groups of students, such as minority and non-minority students or socioeconomically disadvantaged and advantaged students, has been the subject of public discourse and research for many years. Research has indicated numerous reasons for the existence of this gap and its impact on…

  4. Structural phase transition, narrow band gap, and room-temperature ferromagnetism in [KNbO{sub 3}]{sub 1−x}[BaNi{sub 1/2}Nb{sub 1/2}O{sub 3−δ}]{sub x} ferroelectrics

    SciTech Connect

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

    2014-09-15

    Structural phase transition, narrow band gap (E{sub g}), and room-temperature ferromagnetism (RTFM) have been observed in the [KNbO{sub 3}]{sub 1−x}[BaNi{sub 1/2}Nb{sub 1/2}O{sub 3−δ}]{sub x} (KBNNO) ceramics. All the samples have single phase perovskite structure, but exhibit a gradual transition behaviour from the orthorhombic to a cubic structure with the increase of x. Raman spectroscopy analysis not only corroborates this doping-induced change in normal structure but also shows the local crystal symmetry for x ≥ 0.1 compositions to deviate from the idealized cubic perovskite structure. A possible mechanism for the observed specific changes in lattice structure is discussed. Moreover, it is noted that KBNNO with compositions x = 0.1–0.3 have quite narrow E{sub g} of below 1.5 eV, much smaller than the 3.2 eV band gap of parent KNbO{sub 3} (KNO), which is due to the increasing Ni 3d electronic states within the gap of KNO. Furthermore, the KBNNO materials present RTFM near a tetragonal to cubic phase boundary. With increasing x from 0 to 0.3, the magnetism of the samples develops from diamagnetism to ferromagnetism and paramagnetism, originating from the ferromagnetic–antiferromagnetic competition. These results are helpful in the deeper understanding of phase transitions, band gap tunability, and magnetism variations in perovskite oxides and show the potential role, such materials can play, in perovskite solar cells and multiferroic applications.

  5. Closing the Achievement Gap by Improving Reading Instruction. Hearing before the Committee on Education and the Workforce. House of Representatives, One Hundred Seventh Congress, First Session (Orlando, Florida, November 13, 2001).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and the Workforce.

    A field hearing of the United States House of Representatives' Committee on Education and the Workforce, entitled "Closing the Achievement Gap by Improving Reading Instruction," was held at Lancaster Elementary School in Orlando, Florida, on November 13, 2001. The hearing begins with welcoming statements by the committee chairman and one…

  6. Behind the Pay Gap

    ERIC Educational Resources Information Center

    Dey, Judy Goldberg; Hill, Catherine

    2007-01-01

    Women have made remarkable gains in education during the past three decades, yet these achievements have resulted in only modest improvements in pay equity. The gender pay gap has become a fixture of the U.S. workplace and is so ubiquitous that many simply view it as normal. "Behind the Pay Gap" examines the gender pay gap for college graduates.…

  7. Achieving omnidirectional photonic band gap in sputter deposited TiO{sub 2}/SiO{sub 2} one dimensional photonic crystal

    SciTech Connect

    Jena, S. Tokas, R. B.; Sarkar, P.; Thakur, S.; Sahoo, N. K.; Haque, S. Maidul; Misal, J. S.; Rao, K. D.

    2015-06-24

    The multilayer structure of TiO{sub 2}/SiO{sub 2} (11 layers) as one dimensional photonic crystal (1D PC) has been designed and then fabricated by using asymmetric bipolar pulse DC magnetron sputtering technique for omnidirectional photonic band gap. The experimentally measured photonic band gap (PBG) in the visible region is well matched with the theoretically calculated band structure (ω vs. k) diagram. The experimentally measured omnidirectional reflection band of 44 nm over the incident angle range of 0°-70° is found almost matching within the theoretically calculated band.

  8. Use of Latent Growth Curve Modeling for Assessing the Effects of Summer and After-School Learning on Adolescent Students' Achievement Gap

    ERIC Educational Resources Information Center

    Lin, Chunn-Ying; Hsieh, Ya-Heng; Chen, Cheng-Hung

    2015-01-01

    Many Western researchers have found that the gaps in the learning progress between students from different socioeconomic statuses primarily occur due to the accumulated effects of long summer vacations, rather than during the school years. However, it remains to be seen whether these findings can be cross-culturally applied to children in Taiwan.…

  9. Equity Within Reach: Insights from the Front Lines of America's Achievement Gap. Results from a Survey of Teach For America Corps Members

    ERIC Educational Resources Information Center

    Smith, Abigail

    2005-01-01

    There is growing consensus among educators and policy makers that the gap in academic outcomes that exists along socio-economic and racial lines is the most pressing educational challenge of the day. Given their daily work teaching in public schools in the nation's lowest-income urban and rural communities, Teach For America teachers--or "corps…

  10. Closing the Achievement Gap for Economically Disadvantaged Students? Analyzing Change since No Child Left Behind Using State Assessments and the National Assessment of Educational Progress

    ERIC Educational Resources Information Center

    Blank, Rolf K.

    2011-01-01

    A critical state-level indicator of progress in public education is student achievement annual performance and change over time. The Council of Chief State School Officers (CCSSO) has been very active in tracking and reporting on student achievement results and using state assessment scores and other data to analyze achievement trends. A central…

  11. Multilayer dielectric narrow band mangin mirror

    NASA Astrophysics Data System (ADS)

    Ahmed, K.; Khan, A. N.; Rauf, A.; Gul, A.

    2014-06-01

    The design of multilayer stack of dielectric films for narrow band mirror is developed using thin film coating software. The proposed design is materialized by employing thin film coating (PVD) method and reflectance in narrow band spectrum range is achieved. Thickness of high and low refractive index material is taken precisely up to nanometer level. The curved coated substrate is cemented with another K9 matching substrate that forms a Mangin mirror for wavelength 650nm. Narrow band mirrors with reflectivity more than 90% has been produced by properly stacking of 21 layers and advantage of the use of this type of mirror as an interference filter is discussed.

  12. Coupling with a narrow-band-gap semiconductor for the enhancement of visible-light photocatalytic activity: preparation of Bi2OxS3-x/Nb6O17 and application to the degradation of methyl orange.

    PubMed

    Yan, Gang; Shi, Hongfei; Tan, Huaqiao; Zhu, Wanbin; Wang, Yonghui; Zang, Hongying; Li, Yangguang

    2016-09-21

    A series of 2D sheet Bi2OxS3-x/Nb6O17 (Bi/Nb) heterostructure photocatalysts were synthesized through a facile hydrothermal vulcanization method between Bi(3+) exchanged K4Nb6O17 and thiourea (NH2CSNH2). XRD results confirm that the heterostructures were composed of Bi2OxS3-x and Nb6O17. HRTEM indicates that Bi2OxS3-x was successfully intercalated into layers of K4Nb6O17. Such large interfacial contacts can be beneficial to the transfer and separation of photogenerated charge carriers. Thus the composites exhibit good photocatalytic performance for the degradation of methyl orange (MO) under visible light irradiation (λ > 400 nm), which is superior to that of both precursors, pure Bi2S3 and K4Nb6O17. Radical capture tests reveal that photogenerated holes h(+) and ˙O2(-) play important roles in the photodegradation of MO. And based on the UV-visible diffuse reflectance spectra (DRS) and the band gap of the semiconductors, the mechanism of the enhanced visible light photocatalytic activity of these composites has been proposed.

  13. Narrowness and Liberality

    ERIC Educational Resources Information Center

    Agresto, John

    2003-01-01

    John Agresto, whose task has been to rebuild the war-ravaged infrastructure of a Middle-Eastern university system, is discouraged to see that narrow expertise is the only goal of education there, to the utter exclusion of intellectual breadth. He comments that, although it is not that bad in the U.S., he feels that doctoral programs as currently…

  14. Gap between active and passive solar heating

    SciTech Connect

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  15. Modeling Science Achievement Differences between Single-Sex and Coeducational Schools: Analyses from Hong Kong, SAR and New Zealand from TIMSS 1995, 1999, and 2003

    ERIC Educational Resources Information Center

    Diaconu, Dana V.

    2012-01-01

    There is a broad interest in narrowing achievement gaps among all groups of students and improving education by scientifically sound methods. On October 25, 2006, the United States Department of Education published new regulations allowing single-sex education in public schools whenever schools think it will improve student achievement. Thus far,…

  16. [Narrow lumbar canal].

    PubMed

    Deshayes, P; Louvel, J P

    1992-03-01

    The diagnosis of spinal stenosis can be strongly suspected when the following symptoms are present: limbs neuralgias with a poorly defined location, paresthesias in several dermatomas neurogenic intermittent claudication. Myelography coupled with scan yields the best information about morphology, levels of stenosis and narrowing factors, bone bridges ligaments and discal structures. If surgery is decided after failure of medical treatment to improve the patient's condition, the choice will be best guided by the myeloscan analysis.

  17. Preparation by Candidate Countries for Involvement in the EU Lifelong Learning Policy: Achievements, Gaps and Challenges. Synthesis of the Monographs Exercise. Interim Report.

    ERIC Educational Resources Information Center

    Masson, Jean-Raymond

    The reforms undertaken in the vocational education and training systems and the public employment services systems of European Union (EU) candidate countries in the 10 years since the transition have resulted in the following achievements: (1) participation in upper secondary and tertiary education has increased and curricula for general education…

  18. Mathematics Achievement Gaps for Elementary and Secondary Students: The Influence of Opportunity to Learn and Special Education Status. Research Brief 14

    ERIC Educational Resources Information Center

    Elliott, Stephen N.; Kurz, Alexander; Tindal, Gerald; Stevens, Joseph; Yel, Nedim

    2014-01-01

    We examined the relationship among key instructional process variables and the achievement of students with and without disabilities as measured by both interim and end-of-year summative assessments. Examination of the instructional process data indicated that students with and without disabilities receiving mathematics instruction in the same…

  19. What Works Clearinghouse Quick Review of the Article "Are High-Quality Schools Enough to Close the Achievement Gap? Evidence from a Social Experiment in Harlem"

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2010

    2010-01-01

    This study examined the effects on academic achievement of offering students enrollment in the Promise Academy charter middle school. The school is sponsored by the Harlem Children's Zone[R], which combines reform-minded charter schools with a web of community services designed to provide a positive and supportive social environment outside of…

  20. Revisiting the Impact of NCLB High-Stakes School Accountability, Capacity, and Resources: State NAEP 1990-2009 Reading and Math Achievement Gaps and Trends

    ERIC Educational Resources Information Center

    Lee, Jaekyung; Reeves, Todd

    2012-01-01

    This study examines the impact of high-stakes school accountability, capacity, and resources under NCLB on reading and math achievement outcomes through comparative interrupted time-series analyses of 1990-2009 NAEP state assessment data. Through hierarchical linear modeling latent variable regression with inverse probability of treatment…

  1. A Framework for Understanding Cross-National and Cross-Ethnic Gaps in Math and Science Achievement: The Case of the United States

    ERIC Educational Resources Information Center

    Guglielmi, R. Sergio; Brekke, Nancy

    2017-01-01

    Comparative international assessments of academic achievement consistently indicate that US students trail behind many peers, particularly those from east Asia, in math and science. Traditional efforts to explain this finding have focused on identifying characteristics that might differentiate the United States from top-performing countries.…

  2. The Impact of Online or F2F Lecture Choice on Student Achievement and Engagement in a Large Lecture-Based Science Course: Closing the Gap

    ERIC Educational Resources Information Center

    Murphy, Cheryl A.; Stewart, John C.

    2015-01-01

    Blended learning options vary and universities are exploring an assortment of instructional combinations, some involving video lectures as a replacement for face-to-face (f2f) lectures. This methodological study investigates the impact of the provision of lecture choice (online or f2f) on overall student achievement and course engagement. This…

  3. Education Watch: New Mexico. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares New Mexico's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how New Mexico is doing in narrowing the academic achievement gap between African American and Latino students and their white,…

  4. Academic Achievement Academy (AAA), 2011-12. Eye on Evaluation. D&A Report No. 13.03

    ERIC Educational Resources Information Center

    Rhea, Anisa

    2013-01-01

    Extending the school day through programs that will supplement core courses, such as offering intensive, after-school tutoring or small-group study sessions in reading and mathematics, is one method districts use to boost school performance and narrow educational achievement gaps between students of different racial and economic backgrounds (Redd…

  5. Education Watch: Kansas. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares Kansas's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how Kansas is doing in narrowing the academic achievement gap between African American, Latino, or low-income students and their white,…

  6. Education Watch: West Virginia. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares West Virginia's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how West Virginia is doing in narrowing the academic achievement gap between African American and Latino students and their…

  7. Education Watch: Missouri. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares Missouri's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how Missouri is doing in narrowing the academic achievement gap between African American and Latino students and their white, middle…

  8. Education Watch: New Hampshire. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares New Hampshire's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how New Hampshire is doing in narrowing the academic achievement gap between poor and non-poor students, the report presents NAEP…

  9. Education Watch: Indiana. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares Indiana's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how Indiana is doing in narrowing the academic achievement gap between African American, Latino, or low-income students and their…

  10. Education Watch: Kentucky. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares Kentucky's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how Kentucky is doing in narrowing the academic achievement gap between African American, Latino, or low-income students and their…

  11. A Comparison of Students' Achievement in Private and Conventional Public Secondary Schools in Malawi from a Gender Perspective

    ERIC Educational Resources Information Center

    Kamwendo, Martha

    2010-01-01

    This article explores differences in achievement between private and conventional public schools with reference to gender in the face of Education for All targets and Millennium Development Goals. It shows that on average the gender gap is narrower in public schools than in private schools and that the pass rate for public school girls is higher…

  12. Education Watch: Ohio. Key Education Facts and Figures. Achievement, Attainment and Opportunity. From Elementary School through College.

    ERIC Educational Resources Information Center

    Education Trust, Washington, DC.

    This report compares Ohio's reading and mathematics performance on the most recent administrations of the state assessment with performance on the National Assessment of Educational Progress (NAEP). To indicate how Ohio is doing in narrowing the academic achievement gap between African American and Latino students and their white, middle class…

  13. Closing the health and nutrition gap in Odisha, India: A case study of how transforming the health system is achieving greater equity.

    PubMed

    Thomas, Deborah; Sarangi, Biraj Laxmi; Garg, Anu; Ahuja, Arti; Meherda, Pramod; Karthikeyan, Sujata R; Joddar, Pinaki; Kar, Rajendra; Pattnaik, Jeetendra; Druvasula, Ramesh; Dembo Rath, Alison

    2015-11-01

    Health equity is high on the international agenda. This study provides evidence of how health systems can be strengthened to improve health equity in a low-income state. The paper presents a case study of how the Government of Odisha in eastern India is transforming the health system for more equitable health and nutrition outcomes. Odisha has a population of over 42 million, high levels of poverty, and poor maternal and child health concentrated in its Southern districts and among Scheduled Tribe and Scheduled Caste communities. Conducted between 2008 and 2012 with the Departments of Health and Family Welfare, and Women and Child Development, the study reviewed a wide range of literature including policy and programme documents, evaluations and studies, published and grey material, and undertook secondary analysis of state level household surveys. It identifies innovative and expanded provision of health services, reforms to the management and development of human resources for health, and the introduction of a number of cash transfer and entitlement schemes as contributing to closing the gap between maternal and child health and nutrition outcomes of Scheduled Tribes, and the Southern districts, compared to the state average. The institutional delivery rate for Scheduled Tribes has risen from 11.7% in 2005-06 to 67.3% in 2011, and from 35.6% to 79.8% for all women. The social gradient has also closed for antenatal and postnatal care and immunisation. Nutrition indicators though improving are proving slower to budge. The paper identifies how political will, committed policy makers and fiscal space energised the health system to promote equity. Sustained political commitment will be required to continue to address the more challenging human resource, health financing and gender issues.

  14. Perceptual narrowing: retrospect and prospect.

    PubMed

    Flom, Ross

    2014-11-01

    Research is reviewed demonstrating perceptual narrowing across a variety of domains. Research is also reviewed showing that the temporal window of perceptual narrowing can be extended and, in some cases, perceptual narrowing can be reversed. Research is also reviewed highlighting the neurophysiological correlates of perceptual narrowing as well as some of the individual neurophysiological differences associated with perceptual narrowing. Various methodological issues associated with perceptual narrowing are also discussed. The broader purpose of this paper, however, is to argue that the term perceptual narrowing fails to capture the dynamic nature of this perceptual process. Finally, it is argued that just as other concepts associated with experience and development are refined and modified as new evidence emerges, likewise we need to evaluate and refine how we conceptualize perceptual narrowing.

  15. The Nanocrystalline State of Narrow Gap Semiconducting Chalcogenides

    DTIC Science & Technology

    2010-08-23

    were carried out by dissolving nanocrystal powder in aqua - regia (HNO3: HCI, 1:3 volumetric ratio) followed by diluting with ultra pure water. A...change, etc Nanocrystalline AgPbmSbTem+2 and PbmSnTem+i material were prepared in reverse micellar assemblies at room temperature conditions. X-ray

  16. Do Some Schools Narrow the Gap? Differential School Effectiveness Revisited

    ERIC Educational Resources Information Center

    Strand, Steve

    2016-01-01

    Relatively little research has explored whether schools differ in their effectiveness for different group of pupils (e.g. by ethnicity, poverty or gender), for different curriculum subjects (e.g. English, mathematics or science) or over time (different cohorts). This paper uses multilevel modelling to analyse the national test results at age 7 and…

  17. Narrowing the Gap between Research and Practice. Special Edition.

    ERIC Educational Resources Information Center

    Wilson, Richard, Ed.

    1989-01-01

    This monograph summarizes recent research on the education of learning disabled students. After an introduction by the editor, individual articles include: "Teaching Listening Skills" (Linda Higbee Mandlebaum and Richard Wilson); "Study-Skills Instruction for Students with Learning Disabilities" (Deborah Gartland);…

  18. Narrowing the gap between medical and mental health evaluation.

    PubMed

    Linn, M W; Linn, S B

    1975-07-01

    Some of the problems facing evaluators of medical care have been dealt with by individuals examining mental health programs. Mental health research has focused more on outcome studies that include a multidimensional approach in evaluation. Techniques have been devised in that field that make the evaluative process patient specific and goal oriented. Borrowing some of these methods to make medical care evaluation include a problem-oriented outcome, which incorporates patient satisfaction, compliance with medical therapy, and relief of symptoms, could lead to more accurate data on the health delivery system.

  19. Narrow Gap, High Mobility, and Stable Pi Conjugated Polymers

    DTIC Science & Technology

    2012-09-20

    applications and other devices of interest to the Air Force with a special focus on photodetectors (especially in the near infrared), solar cells , and...to be used as the active polymer in PCBM based solar cells . 6 Simplifying our chemistry, we have developed Stille coupling polymerization...weight illustrated in Table 1, such as the Mn = 30.5 kDa (red) and 35.1 kDa (blue) prepared via the Stille method provided effective solar cell

  20. Pharma-nutrition interface: the gap is narrowing.

    PubMed

    Georgiou, Niki A; Garssen, Johan; Witkamp, Renger F

    2011-01-25

    The interaction between pharmacology and nutrition science is on the rise. Nutritional status is considered one of the important determinants of health and disease and several diseases of our time have a clear link with lifestyle factors including the diet. There is also increasing realization that a continuum between health and disease often exists without strict boundaries. Understanding the subtle interactions between genes, environment and homeostatic processes is the key in finding effective ways to prevent, treat or manage disease. Both pharmacologists and nutritionists are recognizing that most of the low hanging fruit has been picked, and that the one disease-one target-one drug (or nutrient) concept will provide fewer successes than it did in the past. Instead, complex multi-factorial diseases require multi-pathway understanding and multi-targeting approaches which will often result in compound combinations. Therapeutic synergy between foods and drugs does not necessarily mean that both have the same primary target. There are also examples of nutritional products that effectively contribute to the therapeutic regimen by improving the patients' general condition or by reducing side-effects of drugs. Examples of conditions and diseases that are highlighted in this review include the metabolic syndrome with its co-morbidities, immune-related diseases and HIV. With the aging population there are other fields emerging, including CNS-related diseases and cancer, where we will likely see an increased synergy between the two disciplines that seemed to have lost contact since the times of Hippocrates.

  1. Exciton absorption in narrow armchair graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Monozon, B. S.; Schmelcher, P.

    2016-11-01

    We develop an analytical approach to the exciton optical absorption for narrow gap armchair graphene nanoribbons (AGNR). We focus on the regime of dominant size quantization in combination with the attractive electron-hole interaction. An adiabatic separation of slow and fast motions leads via the two-body Dirac equation to the isolated and coupled subband approximations. Discrete and continuous exciton states are in general coupled and form quasi-Rydberg series of purely discrete and resonance type character. The corresponding oscillator strengths and widths are derived. We show that the exciton peaks are blue-shifted, become broader and increase in magnitude upon narrowing the ribbon. At the edge of a subband the singularity related to the 1D density of states is transformed into finite absorption via the presence of the exciton. Our analytical results are in good agreement with those obtained by other methods including numerical approaches. Estimates of the expected experimental values are provided for realistic AGNR.

  2. Narrow Angle movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  3. The Structure of A Pacific Narrow Cold Frontal Rainband

    NASA Technical Reports Server (NTRS)

    Jorgensen, David P.; Pu, Zhaoxia; Persson, Ola; Tao, Wei-Kuo; Starr, David OC. (Technical Monitor)

    2002-01-01

    A NOAA P-3 instrumented aircraft observed an intense, fast-moving narrow cold frontal Farmhand as it approached the Pacific Northwest coast on 19 February 2001 during the Pacific Coastal Jets Experiment. Pseudo-dual-Doppler analyses performed on the airborne Doppler radar data while the frontal system was well offshore indicated that a narrow ribbon of very high radar reflectively convective cores characterized the Farmhand at low levels with echo tops to approximately 4-5 km. The NCFR exhibited gaps in its narrow ribbon of high reflectively, probably as a result of hydrodynamic instability all no its advancing cold pool leading edge. In contrast to some earlier studies of cold frontal rainbands, density current theory described well the motion of the overall front. The character of the updraft structure associated with the heavy rainfall at its leading edge varied across the gap region. The vertical shear of the cross-frontal low-level ambient flow exerted a strong influence on the updraft character, consistent with theoretical arguments developed for squall lines describing the balance of vorticity at the leading edge. In short regions south of the gaps the vertical wind shear was strongest with the updrafts and rain shafts more intense, narrower, and more erect or even downshear tilted. North of the gaps the wind shear weakened with less intense Dihedrals which tilted upshear with a broader band of rainfall. Simulations using a nonhydrostatic mesoscale nested grid model are used to investigate the gap regions, particularly the balance of cold pool induced to pre-frontal ambient shears at the leading edge. Observations confirm the model results that the updraft character depends on the balance of vorticity at the leading edge. Downshear-tilted updrafts imply that convection south of the gap regions would weaken with time relative to the frontal segments north of the gaps since inflow air would be affected by passage through the heavy rain region before ascent

  4. NFC - Narrow Field Camera

    NASA Astrophysics Data System (ADS)

    Koukal, J.; Srba, J.; Gorková, S.

    2015-01-01

    We have been introducing a low-cost CCTV video system for faint meteor monitoring and here we describe the first results from 5 months of two-station operations. Our system called NFC (Narrow Field Camera) with a meteor limiting magnitude around +6.5mag allows research on trajectories of less massive meteoroids within individual parent meteor showers and the sporadic background. At present 4 stations (2 pairs with coordinated fields of view) of NFC system are operated in the frame of CEMeNt (Central European Meteor Network). The heart of each NFC station is a sensitive CCTV camera Watec 902 H2 and a fast cinematographic lens Meopta Meostigmat 1/50 - 52.5 mm (50 mm focal length and fixed aperture f/1.0). In this paper we present the first results based on 1595 individual meteors, 368 of which were recorded from two stations simultaneously. This data set allows the first empirical verification of theoretical assumptions for NFC system capabilities (stellar and meteor magnitude limit, meteor apparent brightness distribution and accuracy of single station measurements) and the first low mass meteoroid trajectory calculations. Our experimental data clearly showed the capabilities of the proposed system for low mass meteor registration and for calculations based on NFC data to lead to a significant refinement in the orbital elements for low mass meteoroids.

  5. Powerful narrow linewidth random fiber laser

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Zhou, Pu

    2016-11-01

    In this paper, we demonstrate a narrow linewidth random fiber laser, which employs a tunable pump laser to select the operating wavelength for efficiency optimization, a narrow-band fiber Bragg grating (FBG) and a section of single mode fiber to construct a half-open cavity, and a circulator to separate pump light input and random lasing output. Spectral linewidth down to 42.31 GHz is achieved through filtering by the FBG. When 8.97 W pump light centered at the optimized wavelength 1036.5 nm is launched into the half-open cavity, 1081.4 nm random lasing with the maximum output power of 2.15 W is achieved, which is more powerful than the previous reported results.

  6. Powerful narrow linewidth random fiber laser

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Zhou, Pu

    2017-03-01

    In this paper, we demonstrate a narrow linewidth random fiber laser, which employs a tunable pump laser to select the operating wavelength for efficiency optimization, a narrow-band fiber Bragg grating (FBG) and a section of single mode fiber to construct a half-open cavity, and a circulator to separate pump light input and random lasing output. Spectral linewidth down to 42.31 GHz is achieved through filtering by the FBG. When 8.97 W pump light centered at the optimized wavelength 1036.5 nm is launched into the half-open cavity, 1081.4 nm random lasing with the maximum output power of 2.15 W is achieved, which is more powerful than the previous reported results.

  7. Multiwatts narrow linewidth fiber Raman amplifiers.

    PubMed

    Feng, Yan; Taylor, Luke; Bonaccini Calia, Domenico

    2008-07-21

    Up to 4.8 W, approximately 10 MHz, 1178 nm laser is obtained by Raman amplification of a distributed feedback diode laser in standard single mode fibers pumped by an 1120 nm Yb fiber laser. More than 10% efficiency and 27 dB amplification is achieved, limited by onset of stimulated Brillouin scattering. The ratio of Raman to Brillouin gain coefficient of a fiber is identified as a figure of merit for building a narrow linewidth fiber Raman amplifier.

  8. Broadband Helps Bridge the Achievement Gap

    ERIC Educational Resources Information Center

    Simmons, Jamal

    2013-01-01

    In education, technology is giving new meaning to the phrase "equal opportunity." Teachers and students in schools across America--urban, rural, wealthy, and impoverished--are gaining access to online learning and all of its benefits through broadband technology. What is broadband? According to the Federal Communications Commission (FCC), it is…

  9. Closing the Achievement Gap Means Transformation

    ERIC Educational Resources Information Center

    Colgren, Chris; Sappington, Neil E.

    2015-01-01

    Educating students in public schools has never been at a higher priority. As this nation enters the informational-based economy public schools are going to be required to educate far more students at a higher and more rigorous level. Inspired by theories of educational equity, this study sought to explore the problem that not all students in…

  10. Close the Achievement Gap with Summer Learning

    ERIC Educational Resources Information Center

    Huggins, Gary

    2012-01-01

    Summer vacation from school can bring afternoons at the swimming pool, family vacations, and maybe a spirit-filled summer camp that ignites a passion for art or rock climbing. But for many children, summer also means setbacks in learning that take a tremendous toll on teaching and student performance over time. PTA leaders can make a vital…

  11. Achievement Gaps Tied to Income Found Widening

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2012-01-01

    The fractious debate over how much schools can counteract poverty's impact on children is far from settled, but a recently published collection of research strongly suggests that until policymakers and educators confront deepening economic and social disparities, poor children will increasingly miss out on finding a path to upward social mobility.…

  12. Closing the achievement gap through modification of neurocognitive and neuroendocrine function: results from a cluster randomized controlled trial of an innovative approach to the education of children in kindergarten.

    PubMed

    Blair, Clancy; Raver, C Cybele

    2014-01-01

    Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children's engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap.

  13. Closing the Achievement Gap through Modification of Neurocognitive and Neuroendocrine Function: Results from a Cluster Randomized Controlled Trial of an Innovative Approach to the Education of Children in Kindergarten

    PubMed Central

    Blair, Clancy; Raver, C. Cybele

    2014-01-01

    Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children’s engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap. PMID:25389751

  14. Gap junctions.

    PubMed

    Goodenough, Daniel A; Paul, David L

    2009-07-01

    Gap junctions are aggregates of intercellular channels that permit direct cell-cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues. Their long evolutionary history has permitted adaptation of gap-junctional intercellular communication to a variety of functions, with multiple regulatory mechanisms. Gap-junctional channels are composed of hexamers of medium-sized families of integral proteins: connexins in chordates and innexins in precordates. The functions of gap junctions have been explored by studying mutations in flies, worms, and humans, and targeted gene disruption in mice. These studies have revealed a wide diversity of function in tissue and organ biology.

  15. Gap Junctions

    PubMed Central

    Goodenough, Daniel A.; Paul, David L.

    2009-01-01

    Gap junctions are aggregates of intercellular channels that permit direct cell–cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues. Their long evolutionary history has permitted adaptation of gap-junctional intercellular communication to a variety of functions, with multiple regulatory mechanisms. Gap-junctional channels are composed of hexamers of medium-sized families of integral proteins: connexins in chordates and innexins in precordates. The functions of gap junctions have been explored by studying mutations in flies, worms, and humans, and targeted gene disruption in mice. These studies have revealed a wide diversity of function in tissue and organ biology. PMID:20066080

  16. Cryogenic Detectors (Narrow Field Instruments)

    NASA Astrophysics Data System (ADS)

    Hoevers, H.; Verhoeve, P.

    Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the

  17. Narrowing the gap: from semiconductor to semimetal in the homologous series of rare-earth zinc arsenides RE(2-y)Zn4As4·n(REAs) and Mn-substituted derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs) (RE = La-Nd, Sm, Gd).

    PubMed

    Lin, Xinsong; Tabassum, Danisa; Mar, Arthur

    2015-12-14

    A homologous series of ternary rare-earth zinc arsenides, prepared by reactions of the elements at 750 °C, has been identified with the formula RE(2-y)Zn4As4·n(REAs) (n = 2, 3, 4) for various RE members. They adopt trigonal structures: RE(4-y)Zn4As6 (RE = La-Nd), space group R3̄m1, Z = 3; RE(5-y)Zn4As7 (RE = Pr, Nd, Sm, Gd), space group P3̄m1, Z = 1; RE(6-y)Zn4As8 (RE = La-Nd, Sm, Gd), space group R3̄m1, Z = 3. The Zn atoms can be partially substituted by Mn atoms, resulting in quaternary derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs). Single-crystal structures were determined for nine ternary and quaternary arsenides RE(2-y)M4As4·n(REAs) (M = Mn, Zn) as representative examples of these series. The structures are built by stacking close-packed nets of As atoms, sometimes in very long sequences, with RE atoms occupying octahedral sites and M atoms occupying tetrahedral sites, resulting in an intergrowth of [REAs] and [M2As2] slabs. The recurring feature of all members of the homologous series is a sandwich of [M2As2]-[REAs]-[M2As2] slabs, while rocksalt-type blocks of [REAs] increase in thickness between these sandwiches with higher n. Similar to the previously known related homologous series REM(2-x)As2·n(REAs) which is deficient in M, this new series RE(2-y)M4As4·n(REAs) exhibits deficiencies in RE to reduce the electron excess that would be present in the fully stoichiometric formulas. Enthalpic and entropic factors are considered to account for the differences in site deficiencies in these two homologous series. Band structure calculations indicate that the semiconducting behaviour of the parent n = 0 member (with CaAl2Si2-type structure) gradually evolves, through a narrowing of the gap between valence and conduction bands, to semimetallic behaviour as the number of [REAs] blocks increases, to the limit of n = ∞ for rocksalt-type REAs.

  18. Closing the Performance Gap.

    ERIC Educational Resources Information Center

    Riggins, Cheryl G.

    2002-01-01

    Describes how the principal of a K-2, 400-student suburban elementary school near Flint, Michigan, worked with her staff and superintendent to develop and implement a strategic plan to close the student achievement gap. Reports significant improvement in reading and math scores after 1 year. (PKP)

  19. Confronting the Autonomy Gap

    ERIC Educational Resources Information Center

    Adamowski, Steven; Petrilli, Michael J.

    2007-01-01

    "The Autonomy Gap," a recent study by the American Institute for Research and the Thomas B. Fordham Institute, found that many public elementary school principals feel constrained by a bureaucracy that impedes their ability to raise student achievement. Unfortunately, those principals are still held accountable for their school's results--even…

  20. Excellence Gaps in Education: Expanding Opportunities for Talented Students

    ERIC Educational Resources Information Center

    Plucker, Jonathan A.; Peters, Scott J.

    2016-01-01

    In "Excellence Gaps in Education," Jonathan A. Plucker and Scott J. Peters shine a spotlight on "excellence gaps"--the achievement gaps among subgroups of students performing at the highest levels of achievement. Much of the focus of recent education reform has been on closing gaps in achievement between students from different…

  1. Narrow-band generation in random distributed feedback fiber laser.

    PubMed

    Sugavanam, Srikanth; Tarasov, Nikita; Shu, Xuewen; Churkin, Dmitry V

    2013-07-15

    Narrow-band emission of spectral width down to ~0.05 nm line-width is achieved in the random distributed feedback fiber laser employing narrow-band fiber Bragg grating or fiber Fabry-Perot interferometer filters. The observed line-width is ~10 times less than line-width of other demonstrated up to date random distributed feedback fiber lasers. The random DFB laser with Fabry-Perot interferometer filter provides simultaneously multi-wavelength and narrow-band (within each line) generation with possibility of further wavelength tuning.

  2. Spectral narrowing of solid state lasers by narrow-band PTR Bragg mirrors

    NASA Astrophysics Data System (ADS)

    Chung, T.; Rapaport, A.; Chen, Y.; Smirnov, V.; Hemmer, M.; Glebov, L. B.; Richardson, M. C.; Bass, M.

    2006-05-01

    Dramatic spectral narrowing of normally broad band lasers, Ti:Sapphire,Cr:LiSAF, and alexandrite was achieved by simply replacing the output mirror with a reflective, volumetric Bragg grating recorded in photo thermal refractive (PTR) glass. The output power of each laser was changed very slightly from that obtained using dielectric coated output mirrors with the same output coupling as the Bragg grating while spectral brightness increased by about three orders of magnitude.

  3. Writing in the elementary science classroom: Teacher beliefs and practices within a narrowing curriculum

    NASA Astrophysics Data System (ADS)

    Leffler, Angela K.

    The narrowed curriculum continues to be challenging for science education as teachers strive to impart content that is on the high-stakes assessments. This Qualitative multiple-case study investigated four experienced, elementary classroom teachers' use of writing in science. It was designed to provide insight into teaching beliefs and practices of how teachers use writing in science opportunities within a narrowing curriculum. Triangulation was achieved through teacher interviews, classroom observations, and document analysis. Three major findings were evident through careful examination of data which is representative of the teacher participants within this study: 1.) Writing is combined with dialogue, multiple applications, activity and audience, 2.) Writing is used as an assessment and as a means to enhance learning, 3.) Writing is prioritized in science with differing schedule approaches. Although these are the major findings there were exceptions that were unique to each individual participant. The findings of this study can inform pre-service, novice and experienced classroom teachers on how to interconnect the two subject areas of writing and science to promote enhancement of learning. By gaining this information, it could diminish the global achievement gap in science.

  4. Early Experience & Multisensory Perceptual Narrowing

    PubMed Central

    Lewkowicz, David J.

    2014-01-01

    Perceptual narrowing is a reflection of early experience and contributes in key ways to perceptual and cognitive development. In general, findings have shown that unisensory perceptual sensitivity in early infancy is broadly tuned such that young infants respond to, and discriminate, native as well as non-native sensory inputs, whereas older infants only respond to native inputs. Recently, my colleagues and I discovered that perceptual narrowing occurs at the multisensory processing level as well. The present article reviews this new evidence and puts it in the larger context of multisensory perceptual development and the role that perceptual experience plays in it. Together, the evidence on unisensory and multisensory narrowing shows that early experience shapes the emergence of perceptual specialization and expertise. PMID:24435505

  5. Closing the Mathematical Achievement Gap Through the Heart To the Brain: A Case Study of Urban High School Mathematics Teachers' Perceptions of How Their Emotional Intelligence Facilitates Instruction and Learning in the Classroom

    NASA Astrophysics Data System (ADS)

    Fang, Chung-Chieh

    The purpose of this qualitative case study was to examine urban high school mathematics teachers' perceptions of how they manage their own and their students' emotional intelligence (EI) to facilitate instruction and learning; their reports of how they handle their emotions as urban mathematics teachers; and their reports of how they manage the emotions of their students. The study focused on the voices of sixteen urban mathematics teachers and was undertaken in reaction to the significant mathematics achievement gap between urban students and their suburban counterparts. The conceptual framework undergirding the study was synthesized work by Daniel Goleman, (1995) and Mayer and Salovey (1997); categorizing emotional intelligence in emotional selfawareness, managing emotions, harnessing emotions, empathy, and handling relationships. Research questions addressing each category were created and from these categories an interview guide was developed. Data gathered during individual teacher interviews was transcribed and sorted into emergent categories using open coding. The findings were organized and presented according to the study's research questions. Urban math teachers reported passion for their students, their feelings affect teaching and learning, and that humor is an important tool in mediating emotions. The study concludes with multiple recommendations for further research and practices. Future studies should compare teachers assuming paternal vs. mentor role when dealing with their students. The study can evaluate if either role has a significant impact in student teacher relationships. A recommendation for practice is for teachers to have professional development experiences focusing on the proper use of humor in the classroom. Humor used properly promotes a positive classroom environment. This is a skill that would be especially beneficial to urban teachers.

  6. Opposed-Flow Flame Spread in a Narrow Channel Apparatus over Thin PMMA Sheets

    NASA Technical Reports Server (NTRS)

    Bornand, G. R.; Olson, Sandra L.; Miller, F. J.; Pepper, J. M.; Wichman, I. S.

    2013-01-01

    Flame spread tests have been conducted over polymethylmethacrylate (PMMA) samples in San Diego State University's Narrow Channel Apparatus (SDSU NCA). The Narrow Channel Apparatus (NCA) has the ability to suppress buoyant flow in horizontally spreading flames, and is currently being investigated as a possible replacement or complement to NASA's current material flammability test standard for non-metallic solids, NASA-STD-(I)-6001B Test 1. The buoyant suppression achieved with a NCA allows for tests to be conducted in a simulated microgravity atmosphere-a characteristic that Test 1 lacks since flames present in Test 1 are buoyantly driven. The SDSU NCA allows for flame spread tests to be conducted with varying opposed flow oxidizer velocities, oxygen percent by volume, and total pressure. Also, since the test sample is placed symmetrically between two confining plates so that there is a gap above and below the sample, this gap can be adjusted. This gap height adjustment allows for a compromise between heat loss from the flame to the confining boundaries and buoyancy suppression achieved by those boundaries. This article explores the effect gap height has on the flame spread rate for 75 µm thick PMMA at 1 atm pressure and 21% oxygen concentration by volume in the SDSU NCA. Flame spread results from the SDSU NCA for thin cellulose fuels have previously been compared to results from tests in actual microgravity at various test conditions with the same sample materials and were found to be in good agreement. This article also presents results from the SDSU NCA for PMMA at 1 atm pressure, opposed oxidizer velocity ranging from 3 to 35 cm/s, oxygen concentration by volume at 21%, 30 %, and 50% and fuel thicknesses of 50 and 75 µm. These results are compared to results obtained in actual microgravity for PMMA obtained at the 4.5s drop tower of MGLAB in Gifu, Japan, and the 5.2s drop tower at NASA's Zero-Gravity Research Facility in Cleveland, OH. This comparison confirms

  7. Critical Heat Flux In Inclined Rectangular Narrow Long Channel

    SciTech Connect

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

    2005-05-01

    In the TMI-2 accident, the lower part of the reactor pressure vessel had been overheated and then rather rapidly cooled down, as was later identified in a vessel investigation project. This accounted for the possibility of gap cooling feasibility. For this reason, several investigations were performed to determine the critical heat flux (CHF) from the standpoint of invessel retention. The experiments are conducted to investigate the general boiling phenomena, and the triggering mechanism for the CHF in a narrow gap using a 5 x 105 mm2 crevice type heater assembly and de-mineralized water. The test parameters include the gap size of 5 mm, and the surface orientation angles from the downward facing position (180o) to the vertical position (90o). The orientation angle affects the bubble layer and escape from the narrow gap. The CHF is less than that in a shorter channel, compared with the previous experiments having a heated length of 35 mmin the copper test section.

  8. High average power, narrow band 248 nm alexandrite laser system

    SciTech Connect

    Kuper, J.W.; Chin, T.C.; Papanestor, P.A.

    1994-12-31

    A compact line-narrowed 248 nm solid state laser source operating at 15 mJ {at} 100 Hz PRF was demonstrated. Constraints due to thermal loading of components were addressed. Tradeoffs between pulse energy and repetition rate were investigated. A method for overcoming thermal dephasing in the THG material was achieved by scanning a slab shaped crystal.

  9. The Achievement Club

    ERIC Educational Resources Information Center

    Rogers, Ibram

    2009-01-01

    When Gabrielle Carpenter became a guidance counselor in Northern Virginia nine years ago, she focused on the academic achievement gap and furiously tried to close it. At first, she was compelled by tremendous professional interest. However, after seeing her son lose his zeal for school, Carpenter joined forces with other parents to form an…

  10. The Wage Gap: Briefing Paper #1.

    ERIC Educational Resources Information Center

    National Committee on Pay Equity, Washington, DC.

    Women have made slow, steady progress in the labor market since 1979, but the wage gap has not narrowed significantly. This briefing paper updates a September 1987 paper based on "Male-Female Differences in Work Experience, Occupations, and Earnings: 1984" (Current Population Reports, Household Economic Studies, Series P-70, No. 10, issued in…

  11. Quantum-Hall Activation Gaps in Graphene

    NASA Astrophysics Data System (ADS)

    Giesbers, A. J. M.; Zeitler, U.; Katsnelson, M. I.; Ponomarenko, L. A.; Mohiuddin, T. M.; Maan, J. C.

    2007-11-01

    We have measured the quantum-Hall activation gaps in graphene at filling factors ν=2 and ν=6 for magnetic fields up to 32 T and temperatures from 4 to 300 K. The ν=6 gap can be described by thermal excitation to broadened Landau levels with a width of 400 K. In contrast, the gap measured at ν=2 is strongly temperature and field dependent and approaches the expected value for sharp Landau levels for fields B>20T and temperatures T>100K. We explain this surprising behavior by a narrowing of the lowest Landau level.

  12. Caring Closes the Language-Learning Gap

    ERIC Educational Resources Information Center

    Borba, Mary

    2009-01-01

    The gap in academic achievement between English speakers and English learners continues to concern educators, parents, and legislators. Rising expectations for literacy and the increasing number of students from diverse backgrounds contribute to this achievement gap. In this article, the author discusses a variety of strategies for reaching out to…

  13. Driven tracers in narrow channels

    NASA Astrophysics Data System (ADS)

    Cividini, J.; Mukamel, D.; Posch, H. A.

    2017-01-01

    Steady-state properties of a driven tracer moving in a narrow two-dimensional (2D) channel of quiescent medium are studied. The tracer drives the system out of equilibrium, perturbs the density and pressure fields, and gives the bath particles a nonzero average velocity, creating a current in the channel. Three models in which the confining effect of the channel is probed are analyzed and compared in this study: the first is the simple symmetric exclusion process (SSEP), for which the stationary density profile and the pressure on the walls in the frame of the tracer are computed. We show that the tracer acts like a dipolar source in an average velocity field. The spatial structure of this 2D strip is then simplified to a one-dimensional (1D) SSEP, in which exchanges of position between the tracer and the bath particles are allowed. Using a combination of mean-field theory and exact solution in the limit where no exchange is allowed gives good predictions of the velocity of the tracer and the density field. Finally, we show that results obtained for the 1D SSEP with exchanges also apply to a gas of overdamped hard disks in a narrow channel. The correspondence between the parameters of the SSEP and of the gas of hard disks is systematic and follows from simple intuitive arguments. Our analytical results are checked numerically.

  14. Bacterial motion in narrow capillaries

    PubMed Central

    Ping, Liyan; Wasnik, Vaibhav; Emberly, Eldon

    2014-01-01

    Motile bacteria often have to pass through small tortuous pores in soil or tissue of higher organisms. However, their motion in this prevalent type of niche is not fully understood. Here, we modeled it with narrow glass capillaries and identified a critical radius (Rc) for bacterial motion. Near the surface of capillaries narrower than that, the swimming trajectories are helices. In larger capillaries, they swim in distorted circles. Under non-slip condition, the peritrichous Escherichia coli swam in left-handed helices with an Rc of ∼10 μm near glass surface. However, slipping could occur in the fast monotrichous Pseudomonas fluorescens, when a speed threshold was exceeded, and thus both left-handed and right-handed helices were executed in glass capillaries. In the natural non-cylindrical pores, the near-surface trajectories would be spirals and twisted loops. Engaging in such motions reduces the bacterial migration rate. With a given pore size, the run length and the tumbling angle of the bacterium determine the probability and duration of their near-surface motion. Shear flow and chemotaxis potentially enhance it. Based on this observation, the puzzling previous observations on bacterial migration in porous environments can be interpreted. PMID:25764548

  15. Promotive and Corrosive Factors in African American Students' Math Beliefs and Achievement.

    PubMed

    Diemer, Matthew A; Marchand, Aixa D; McKellar, Sarah E; Malanchuk, Oksana

    2016-06-01

    Framed by expectancy-value theory (which posits that beliefs about and the subjective valuation of a domain predict achievement and decision-making in that domain), this study examined the relationships among teacher differential treatment and relevant math instruction on African American students' self-concept of math ability, math task value, and math achievement. These questions were examined by applying structural equation modeling to 618 African American youth (45.6 % female) followed from 7th to 11th grade in the Maryland Adolescent Development in Context Study. While controlling for gender and prior math achievement, relevant math instruction promoted and teacher differential treatment corroded students' math beliefs and achievement over time. Further, teacher discrimination undermined students' perceptions of their teachers, a mediating process under-examined in previous inquiry. These findings suggest policy and practice levers to narrow opportunity gaps, as well as foster math achievement and science, technology, engineering and math success.

  16. The Vector Calculus Gap: Mathematics (Does Not Equal) Physics.

    ERIC Educational Resources Information Center

    Dray, Tevian; Manogue, Corinne A.

    1999-01-01

    Discusses some of the differences between the ways mathematicians and physicists view vector calculus and the gap between the way this material is traditionally taught by mathematicians and the way physicists use it. Suggests some ways to narrow the gap. (Author/ASK)

  17. Community College Enrollment, College Major, and the Gender Wage Gap.

    ERIC Educational Resources Information Center

    Gill, Andrew M.; Leigh, Duane E.

    2000-01-01

    Independent cross-sections developed using National Longitudinal Survey data reveal a decrease in the gender wage gap from 1989-1994 due to fewer differences in tenure and full-time employment. Disaggregating education by two- and four-year providers and college major accounts for 8.5-11% of the narrower wage gap for the period. (SK)

  18. Prospects for a narrow line MOT in YO

    NASA Astrophysics Data System (ADS)

    Collopy, Alejandra L.; Hummon, Matthew T.; Yeo, Mark; Yan, Bo; Ye, Jun

    2015-05-01

    In addition to being suitable for laser cooling and trapping in a magneto-optical trap (MOT) using a relatively broad (∼ 5 MHz) transition, the molecule YO possesses a narrow-line transition. This forbidden transition between the {{X}2}Σ and A{{\\prime }2}{{Δ }3/2} states has linewidth ∼ 2π × 160 kHz. After cooling in a MOT on the 614 nm {{X}2}Σ to {{A}2}{{\\Pi }1/2} (orange) transition, the narrow 690 nm (red) transition can be used to further cool the sample, requiring only minimal additions to the first stage system. We estimate that the narrow line cooling stage will bring the temperature from ∼1 mK to ∼10 μK, significantly advancing the frontier on direct cooling achievable for molecules.

  19. Line Narrowing Parameter Measurement by Modulation Spectroscopy

    NASA Technical Reports Server (NTRS)

    Dharamsi, Amin N.

    1998-01-01

    that the measurement was yielded a very sensitive technique for obtaining the narrowing parameter that describes the deviation of Oxygen A-band lines from the Voigt profile. In particular, it was seen that the best fits were obtained consistently when the narrowing parameter value used was 0.022 1/cm, 1/Atm, Previous work, upon which the current work was based has resulted in several accurate measurements of properties of particular lines of the Oxygen A band. For example, this work has resulted in the measurement of the collision cross sections of several lines including the RQ(13,14) and the RR(15,15) lines. A major achievement of achievement of the work was also the demonstration that the technique we have developed can accurately probe the structure of the absorption lineshape function. In particular, the method we have developed is very well suited for experimentally probing the characteristics of lines in their wings. This work was accepted for publication in the Journal of Applied Physics, and is scheduled to appear in the December 15, 1998 issue.

  20. Aerodynamic and Acoustic Effects of Ventricular Gap

    PubMed Central

    Alipour, Fariborz; Karnell, Michael

    2013-01-01

    Purpose Supraglottic compression is frequently observed in individuals with dysphonia. It is commonly interpreted as an indication of excessive circumlaryngeal muscular tension and ventricular medialization. The purpose of this study was to describe the aerodynamic and acoustic impact of varying ventricular medialization in a canine model. Methods Subglottal air pressure, glottal airflow, electroglottograph, acoustic signals and high-speed video images were recorded in seven excised canine larynges mounted in vitro for laryngeal vibratory experimentation. The degree of gap between the ventricular folds was adjusted and measured using sutures and weights. Data was recorded during phonation when the ventricular gap was narrow, neutral, and large. Glottal resistance was estimated by measures of subglottal pressure and glottal flow. Results Glottal resistance increased systematically as ventricular gap became smaller. Wide ventricular gaps were associated with increases in fundamental frequency and decreases in glottal resistance. Sound pressure level did not appear to be impacted by the adjustments in ventricular gap used in this research. Conclusions Increases in supraglottic compression and associated reduced ventricular width may be observed in a variety of disorders that affect voice quality. Ventricular compression may interact with true vocal fold posture and vibration resulting in predictable changes in aerodynamic, physiologic, acoustic, and perceptual measures of phonation. The data from this report supports the theory that narrow ventricular gaps may be associated with disordered phonation. In vitro and in vivo human data are needed to further test this association. PMID:24321590