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. Copyright © 2013 Elsevier Inc. All rights reserved.

Design, Construction, Demonstration and Delivery of an Automated Narrow Gap Welding System.

DTIC Science & Technology

1983-03-31

evaluated on the Narrow Gap welding system. By using the combinational qas shielding assembly, it is now possible to reduce the gas flow rates to a value...AD-A145 496 DESIGN CONSTRUCTION DEMONSTRATION AND DE IVER OF AN AUTOMATED NARROW GAP WELDING SYSTEM(U) CRC AUTOMATIC WELDING CO HODSTON SX 31 MAR 83...STANDARDS-963 - A CRC REPORT NO. NAV A/W 7 0PHASE 3 REPORT ON SDESIGN, CONSTRUCTION, DEMONSTRATION AND DELIVERY OF AN AUTOMATED NARROW GAP WELDING

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.

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

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

ERIC Educational Resources Information Center

Flores, Patricia Arleen

2010-01-01

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

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.

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

PubMed

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

2016-08-24

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

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…

Narrowing the Literacy Achievement Gap in Elementary Grades

ERIC Educational Resources Information Center

Dailey, Mary Callan

2014-01-01

This study addressed the gap in practice of instructional literacy, as evidenced by below-proficient literacy status by subgroups of regular education students in Grades 3-5 in an affluent suburban New Jersey public school district. The purpose of this qualitative grounded theory investigation, approached from an interpretive constructivist…

Diluted magnetic semiconductors with narrow band gaps

NASA Astrophysics Data System (ADS)

Gu, Bo; Maekawa, Sadamichi

2016-10-01

We propose a method to realize diluted magnetic semiconductors (DMSs) with p - and n -type carriers by choosing host semiconductors with a narrow band gap. By employing a combination of the density function theory and quantum Monte Carlo simulation, we demonstrate such semiconductors using Mn-doped BaZn2As2 , which has a band gap of 0.2 eV. In addition, we found a nontoxic DMS Mn-doped BaZn2Sb2 , of which the Curie temperature Tc is predicted to be higher than that of Mn-doped BaZn2As2 , the Tc of which was up to 230 K in a recent experiment.

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…

Effects of gap width on droplet transfer behavior in ultra-narrow gap laser welding of high strength aluminum alloys

NASA Astrophysics Data System (ADS)

Song, Chaoqun; Dong, Shiyun; Yan, Shixing; He, Jiawu; Xu, Binshi; He, Peng

2017-10-01

Ultra-narrow gap laser welding is a novel method for thick high strength aluminum alloy plate for its lower heat input, less deformation and higher efficiency. To obtain a perfect welding quality, it is vital to control the more complex droplet transfer behavior under the influence of ultra-narrow gap groove. This paper reports the effects of gap width of groove on droplet transfer behavior in ultra-narrow gap laser welding of 7A52 aluminum alloy plates by a high speed camera, using an ER 5356 filler wire. The results showed that the gap width had directly effects on droplet transfer mode and droplet shape. The droplet transfer modes were, in order, both-sidewall transfer, single-sidewall transfer, globular droplet transfer and bridging transfer, with different droplet shape and transition period, as the gap width increased from 2 mm to 3.5mm. The effect of gap width on lack of fusion was also studied to analyze the cause for lack of fusion at the bottom and on the sidewall of groove. Finally, with a 2.5 mm U-type parallel groove, a single-pass joint with no lack of fusion and other macro welding defects was successfully obtained in a single-sidewall transfer mode.

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

ERIC Educational Resources Information Center

Bolden, Felicia Mickles

2012-01-01

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

Instructional Strategies and Best Practices for Improving the Achievement Gap in Mathematics: An Exploratory Case Study

ERIC Educational Resources Information Center

Lord, Joey

2017-01-01

This qualitative exploratory case study focused on the achievement gap in mathematics that exists in one urban North Carolina middle school and the strategies used by school personnel to narrow this gap. The goal of this research was to determine effective instructional strategies and best practices used to engage students in learning that will…

Narrowing the Achievement Gap: A Case Study of One Outperforming Urban School Making A Difference

ERIC Educational Resources Information Center

Garner, Dionne M.

2017-01-01

Despite efforts to positively impact educational outcomes for underrepresented youth, the achievement gap persists in the United States. Underrepresented youth are students representing lower socioeconomic, racial, ethnic, or language minority populations that are underrepresented in higher educational attainment relative to their numbers in the…

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).…

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…

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…

Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials

NASA Astrophysics Data System (ADS)

Song, Justin C. W.; Kats, Mikhail A.

2016-12-01

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 six 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.

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...

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

ERIC Educational Resources Information Center

Wright, Howell, Jr.; Harris, Sandra

2010-01-01

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

Thermoelectricity in correlated narrow-gap semiconductors

NASA Astrophysics Data System (ADS)

Tomczak, Jan M.

2018-05-01

We review many-body effects, their microscopic origin, as well as their impact on thermoelectricity in correlated narrow-gap semiconductors. Members of this class—such as FeSi and FeSb2—display an unusual temperature dependence in various observables: insulating with large thermopowers at low temperatures, they turn bad metals at temperatures much smaller than the size of their gaps. This insulator-to-metal crossover is accompanied by spectral weight-transfers over large energies in the optical conductivity and by a gradual transition from activated to Curie–Weiss-like behaviour in the magnetic susceptibility. We show a retrospective of the understanding of these phenomena, discuss the relation to heavy-fermion Kondo insulators—such as Ce3Bi4Pt3 for which we present new results—and propose a general classification of paramagnetic insulators. From the latter, FeSi emerges as an orbital-selective Kondo insulator. Focussing on intermetallics such as silicides, antimonides, skutterudites, and Heusler compounds we showcase successes and challenges for the realistic simulation of transport properties in the presence of electronic correlations. Further, we explore new avenues in which electronic correlations may contribute to the improvement of thermoelectric performance.

Boiling Visualization and Critical Heat Flux Phenomena In Narrow Rectangular Gap

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. J. Kim; Y. H. Kim; S. J. Kim

2004-12-01

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

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

Pseudomorphic Narrow Gap Materials for High Performance Devices

DTIC Science & Technology

1993-04-14

research under this program is ito obtain hiigh quality pseudomorphic (strained) narrow gap materials for high performance device applicatjons During...1993 ELECTE """ ’I ~01lG:9395 APR21 W93 Dr. Max N. Yoder Scientific Officer, Code 114SS Office of Naval Research 800 N. Quincy Street Arlington, VA...Mr. V. Morano - w/cy each/ ...- Administrative Grants Officer Office of Naval Research . r. - Resident Representative, N6Z9g7 -- _ z 33 Third Avenue

Reducing the White-Nonwhite Achievement Gap.

ERIC Educational Resources Information Center

Ramey, Madelaine

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

An Examination of Effective Practice: Moving Toward Elimination of Achievement Gaps in Science

NASA Astrophysics Data System (ADS)

Johnson, Carla C.

2009-06-01

This longitudinal study of middle school science teachers explored the relationship between effective science instruction, as defined by the National Science Education Standards (NRC in National science education standards. National Academy Press, Washington, DC, 1996), and student achievement in science. Eleven teachers participated in a three year study of teacher effectiveness, determined by the LSC Classroom Observation Protocol (Horizon Research, Inc. in Local Systemic Change Classroom Observation Protocol. May 1, 2002) and student achievement, which was assessed using the Discovery Inquiry Test in Science. Findings in this study revealed the positive impact that effective science teachers have on student learning, eliminating achievement gaps between White and Non-White students. Case studies of three teachers, both effective and ineffective explore the beliefs and experiences that influence teachers to change, or not to change practice. This study provides justification for teaching science effectively to narrow achievement gaps in science and provides insight to stakeholders in science education as to how to support teachers in becoming more effective, through addressing existing teacher beliefs and providing experiences that challenge those beliefs.

Microstructure and Mechanical Properties of Narrow Gap Laser-Arc Hybrid Welded 40 mm Thick Mild Steel.

PubMed

Zhang, Chen; Li, Geng; Gao, Ming; Zeng, XiaoYan

2017-01-26

Both laser-arc hybrid welding and narrow gap welding have potential for the fabrication of thick sections, but their combination has been seldom studied. In this research, 40 mm thick mild steel was welded by narrow gap laser-arc hybrid welding. A weld with smooth layer transition, free of visible defects, was obtained by nine passes at a 6 mm width narrow gap. The lower part of the weld has the lowest mechanical properties because of the lowest amount of acicular ferrite, but its ultimate tensile strength and impact absorbing energy is still 49% and 60% higher than those of base metal, respectively. The microhardness deviation of all filler layers along weld thickness direction is no more than 15 HV 0.2 , indicating that no temper softening appeared during multiple heat cycles. The results provide an alternative technique for improving the efficiency and quality of welding thick sections.

Microstructure and Mechanical Properties of Narrow Gap Laser-Arc Hybrid Welded 40 mm Thick Mild Steel

PubMed Central

Zhang, Chen; Li, Geng; Gao, Ming; Zeng, XiaoYan

2017-01-01

Both laser-arc hybrid welding and narrow gap welding have potential for the fabrication of thick sections, but their combination has been seldom studied. In this research, 40 mm thick mild steel was welded by narrow gap laser-arc hybrid welding. A weld with smooth layer transition, free of visible defects, was obtained by nine passes at a 6 mm width narrow gap. The lower part of the weld has the lowest mechanical properties because of the lowest amount of acicular ferrite, but its ultimate tensile strength and impact absorbing energy is still 49% and 60% higher than those of base metal, respectively. The microhardness deviation of all filler layers along weld thickness direction is no more than 15 HV0.2, indicating that no temper softening appeared during multiple heat cycles. The results provide an alternative technique for improving the efficiency and quality of welding thick sections. PMID:28772469

An Examination of the Achievement Gap and School A-F Letter Grades in a Southwest County in the United States

ERIC Educational Resources Information Center

Jacobson, Jason A.

2016-01-01

Research has suggested the "No Child Left Behind Act" passed in 2001 has resulted in narrowed curriculum and a failed attempt at its primary objective to close the achievement gap. Understanding changes that have occurred in student achievement from 2011 to 2014 of the NCLB requirements is the focus of this quantitative ex-post facto…

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…

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. …

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramakanth, S.; James Raju, K. C., E-mail: kcjrsp@uohyd.ernet.in; School of Physics, University of Hyderabad, Hyderabad 500046

2014-05-07

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

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.

School Choice and the Achievement Gap

ERIC Educational Resources Information Center

Jeynes, William H.

2014-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlov, D. V., E-mail: dvkoz@impras.ru; Rumyantsev, V. V.; Morozov, S. V.

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.

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.

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…

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…

Facile doping of anionic narrow-band-gap conjugated polyelectrolytes during dialysis.

PubMed

Mai, Cheng-Kang; Zhou, Huiqiong; Zhang, Yuan; Henson, Zachary B; Nguyen, Thuc-Quyen; Heeger, Alan J; Bazan, Guillermo C

2013-12-02

PCPDTBTSO3 K, an anionic, narrow-band-gap conjugated polyelectrolyte, was found to be doped after dialysis. The proposed doping mechanism involves protonation of the polymer backbone, followed by electron transfer from a neutral chain, to generate radical cations, which are stabilized by the pendant sulfonate anions. Formation of polarons is supported by spectroscopy and electrical-conductivity measurements. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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…

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

ERIC Educational Resources Information Center

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

2008-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2012-09-26

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

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…

Aiming at Narrowing Social Gaps in Israel through a Special Program of Everyman's University.

ERIC Educational Resources Information Center

Guri, Sarah

The philosophy and implementation of the Community Leaders Project at Everyman's University (EU), the Open University of Israel, are discussed. The project is designed to narrow social gaps in Israel by upgrading the educational level of disadvantaged populations and by developing indigeneous leadership for decision-making in the most…

Valuing both critical and creative thinking in clinical practice: narrowing the research-practice gap?

PubMed

Seymour, Beth; Kinn, Sue; Sutherland, Norrie

2003-05-01

Nurturing critical thinking skills in the classroom is considered an important educational activity. It is believed that critical thinking skills are transferable and that they can be applied in practice when appraising, evaluating and implementing research. That more nurses than ever before have been judged academically knowledgeable in research has not guaranteed the transfer of such knowledge to practice. This paper discusses some of the reasons for the failure to narrow the gap between research and practice. In particular we argue that, if nurses are encouraged to develop creative and generative thinking alongside their critical thinking skills, then the art of nursing will have fuller representation in education, research and practice. The successful development of critical thinking skills for academic purposes does not necessarily mean that these skills are used in practice in relation either to research or clinical decision-making. This suggests that the transferability of critical thinking skills is less than straightforward. Indeed, there has been little narrowing of the research-practice gap since students started to learn critical thinking for academic purposes. However, we propose that thinking skills can be encouraged in the context of practice and that regular educational events, such as journal clubs, can contribute to developing critical thinking in the practice environment. The research-practice gap will reduce only if research becomes part of practitioners' ideology, which includes the art and science of nursing. Critical and creative thinking are prerequisites to narrowing the disjuncture between research and practice, and we suggest that educators and practitioners explore structured ways of meeting together to appraise literature as a possible means of making use of their thinking and knowledge in clinical practice.

The Hispanic-Asian Achievement Gap in Elementary School

ERIC Educational Resources Information Center

Martinez, Lina Maria

2012-01-01

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

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…

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.

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

ERIC Educational Resources Information Center

Viadero, Debra

2000-01-01

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

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

ERIC Educational Resources Information Center

Fryer, Roland G., Jr.

2010-01-01

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

Vision and spectroscopic sensing for joint tracing in narrow gap laser butt welding

NASA Astrophysics Data System (ADS)

Nilsen, Morgan; Sikström, Fredrik; Christiansson, Anna-Karin; Ancona, Antonio

2017-11-01

The automated laser beam butt welding process is sensitive to positioning the laser beam with respect to the joint because a small offset may result in detrimental lack of sidewall fusion. This problem is even more pronounced in case of narrow gap butt welding, where most of the commercial automatic joint tracing systems fail to detect the exact position and size of the gap. In this work, a dual vision and spectroscopic sensing approach is proposed to trace narrow gap butt joints during laser welding. The system consists of a camera with suitable illumination and matched optical filters and a fast miniature spectrometer. An image processing algorithm of the camera recordings has been developed in order to estimate the laser spot position relative to the joint position. The spectral emissions from the laser induced plasma plume have been acquired by the spectrometer, and based on the measurements of the intensities of selected lines of the spectrum, the electron temperature signal has been calculated and correlated to variations of process conditions. The individual performances of these two systems have been experimentally investigated and evaluated offline by data from several welding experiments, where artificial abrupt as well as gradual deviations of the laser beam out of the joint were produced. Results indicate that a combination of the information provided by the vision and spectroscopic systems is beneficial for development of a hybrid sensing system for joint tracing.

The contribution of the polio eradication initiative to narrowing the gaps in the health workforce in the African Region.

PubMed

Kamso, Jean; Mvika, Eddy S; Ota, M O C; Okeibunor, Joseph; Mkanda, Pascal; Mihigo, Richard

2016-10-10

The Global Polio Eradication Initiative (GPEI) massively invested to overcome the crippling disease in countries of the WHO African Region. In the context of economic crisis, almost all countries in the Region lack an adequate health workforce. Large amounts were invested by GPEI in human resources. This paper shows how the human resources funded by polio contributed to narrowing the gaps in health workforce and helped strengthening and supporting other priority health programmes in Angola, Chad, DRC, Nigeria, Tanzania, and Togo. The health workforce strengthening methods used in the five different countries included the following: policy development and strategic planning, microplanning, capacity building of public health and community workers, implementation and services, monitoring and evaluation, advocacy and social mobilization, and programme review. Staff funded by polio helped with achieving good coverage in vitamin A and insecticide-treated mosquito nets (Angola, Chad); improvement of EPI and integrated disease surveillance indicators, improved quality of data (all five countries), administrative support, smooth introduction of new vaccines, increased case detection, and early isolation of patients suffering from the Guinea worm (Chad); reduction of cholera, extension of directly observed TB short course treatment (Democratic Republic of Congo); significant staff performance improvement (Nigeria). GPEI investment achieved far beyond its primary goal, and contributed to narrowing the gaps in the health workforce in countries of the African Region, as demonstrated by the best practice documentation exercise. We recommend that expertise and experience of polio funded staff should be leveraged to strengthen, expand and support other public health programmes. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Crossovers from excitons to plasmons in narrow-gap carbon nanotubes

NASA Astrophysics Data System (ADS)

Uryu, Seiji

2018-06-01

Plasmons and excitons, bound states of electrons and holes, are collective charge excitations in solids. In this study, we numerically show that in most metallic carbon nanotubes, which are called narrow-gap carbon nanotubes, excitons cross over to plasmons as the wave vector increases. This indicates that resonance with the excitons changes to that with the plasmons by changing the nanotube length, which can explain the origin of observed peaks in the terahertz or far-infrared region in the optical absorption spectra of metallic carbon nanotubes. In the crossovers from excitons to plasmons, a depolarization effect on the many-body wave functions of the plasmons and excitons is clarified.

Strategies for narrowing the maize yield gap of household farms through precision fertigation under irrigated conditions using CERES-Maize model.

PubMed

Liu, Jiangang; Wang, Guangyao; Chu, Qingquan; Chen, Fu

2017-07-01

Nitrogen (N) application significantly increases maize yield; however, the unreasonable use of N fertilizer is common in China. The analysis of crop yield gaps can reveal the limiting factors for yield improvement, but there is a lack of practical strategies for narrowing yield gaps of household farms. The objectives of this study were to assess the yield gap of summer maize using an integrative method and to develop strategies for narrowing the maize yield gap through precise N fertilization. The results indicated that there was a significant difference in maize yield among fields, with a low level of variation. Additionally, significant differences in N application rate were observed among fields, with high variability. Based on long-term simulation results, the optimal N application rate was 193 kg ha -1 , with a corresponding maximum attainable yield (AY max ) of 10 318 kg ha -1 . A considerable difference between farmers' yields and AY max was observed. Low agronomic efficiency of applied N fertilizer (AE N ) in farmers' fields was exhibited. The integrative method lays a foundation for exploring the specific factors constraining crop yield gaps at the field scale and for developing strategies for rapid site-specific N management. Optimization strategies to narrow the maize yield gap include increasing N application rates and adjusting the N application schedule. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Achieving an ultra-narrow multiband light absorption meta-surface via coupling with an optical cavity.

PubMed

Liu, Zhengqi; Liu, Guiqiang; Liu, Xiaoshan; Huang, Shan; Wang, Yan; Pan, Pingping; Liu, Mulin

2015-06-12

Resonant plasmonic and metamaterial absorbers are of particular interest for applications in a wide variety of nanotechnologies including thermophotovoltaics, photothermal therapy, hot-electron collection and biosensing. However, it is rather challenging to realize ultra-narrow absorbers using plasmonic materials due to large optical losses in metals that inevitably decrease the quality of optical resonators. Here, we theoretically report methods to achieve an ultra-narrow light absorption meta-surface by using photonic modes of the optical cavities, which strongly couple with the plasmon resonances of the metallic nanostructures. Multispectral light absorption with absorption amplitude exceeding 99% and a bandwidth approaching 10 nm is achieved at the optical frequencies. Moreover, by introducing a thick dielectric coupling cavity, the number of absorption bands can be strongly increased and the bandwidth can even be narrowed to less than 5 nm due to the resonant spectrum splitting enabled by strong coupling between the plasmon resonances and the optical cavity modes. Designing such optical cavity-coupled meta-surface structures is a promising route for achieving ultra-narrow multiband absorbers, which can be used in absorption filters, narrow-band multispectral thermal emitters and thermophotovoltaics.

Evidence for Itinerant Carriers in an Anisotropic Narrow-Gap Semiconductor by Angle-Resolved Photoemission Spectroscopy.

PubMed

Ju, Sailong; Bai, Wei; Wu, Liming; Lin, Hua; Xiao, Chong; Cui, Shengtao; Li, Zhou; Kong, Shuai; Liu, Yi; Liu, Dayong; Zhang, Guobin; Sun, Zhe; Xie, Yi

2018-01-01

The ability to accurately determine the electronic structure of solids has become a key prerequisite for modern functional materials. For example, the precise determination of the electronic structure helps to balance the three thermoelectric parameters, which is the biggest challenge to design high-performance thermoelectric materials. Herein, by high-resolution, angle-resolved photoemission spectroscopy (ARPES), the itinerant carriers in CsBi 4 Te 6 (CBT) are revealed for the first time. CBT is a typical anisotropic, narrow-gap semiconductor used as a practical candidate for low-temperature thermoelectric applications, and p-doped CBT series show superconductivity at relatively low carrier concentrations. The ARPES results show a significantly larger bandwidth near the Fermi surface than calculations, which means the carriers transport anisotropically and itinerantly in CBT. It is reasonable to believe that these newly discovered features of carriers in narrow-gap semiconductors are promising for designing optimal thermoelectric materials and superconductors. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Narrowing of band gap at source/drain contact scheme of nanoscale InAs-nMOS

NASA Astrophysics Data System (ADS)

Mohamed, A. H.; Oxland, R.; Aldegunde, M.; Hepplestone, S. P.; Sushko, P. V.; Kalna, K.

2018-04-01

A multi-scale simulation study of Ni/InAs nano-scale contact aimed for the sub-14 nm technology is carried out to understand material and transport properties at a metal-semiconductor interface. The deposited Ni metal contact on an 11 nm thick InAs channel forms an 8.5 nm thick InAs leaving a 2.5 nm thick InAs channel on a p-type doped (1 × 1016 cm-3) AlAs0.47Sb0.53 buffer. The density functional theory (DFT) calculations reveal a band gap narrowing in the InAs at the metal-semiconductor interface. The one-dimensional (1D) self-consistent Poisson-Schrödinger transport simulations using real-space material parameters extracted from the DFT calculations at the metal-semiconductor interface, exhibiting band gap narrowing, give a specific sheet resistance of Rsh = 90.9 Ω/sq which is in a good agreement with an experimental value of 97 Ω/sq.

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)

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,…

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

PubMed Central

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

2013-01-01

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. PMID:24311951

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.

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

ERIC Educational Resources Information Center

Alson, Allan

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

Closing Achievement Gaps: Lessons from the Last 15 Years

ERIC Educational Resources Information Center

Murphy, Joseph

2009-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jia, E-mail: jiali@hebut.edu.cn; Research Institute for Energy Equipment Materials, Hebei University of Technology, Tianjin 300401; Zhang, Zhidong

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 ofmore » 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.« less

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.

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…

The effect of exchange interaction on quasiparticle Landau levels in narrow-gap quantum well heterostructures.

PubMed

Krishtopenko, S S; Gavrilenko, V I; Goiran, M

2012-04-04

Using the 'screened' Hartree-Fock approximation based on the eight-band k·p Hamiltonian, we have extended our previous work (Krishtopenko et al 2011 J. Phys.: Condens. Matter 23 385601) on exchange enhancement of the g-factor in narrow-gap quantum well heterostructures by calculating the exchange renormalization of quasiparticle energies, the density of states at the Fermi level and the quasiparticle g-factor for different Landau levels overlapping. We demonstrate that exchange interaction yields more pronounced Zeeman splitting of the density of states at the Fermi level and leads to the appearance of peak-shaped features in the dependence of the Landau level energies on the magnetic field at integer filling factors. We also find that the quasiparticle g-factor does not reach the maximum value at odd filling factors in the presence of large overlapping of spin-split Landau levels. We advance an argument that the behavior of the quasiparticle g-factor in weak magnetic fields is defined by a random potential of impurities in narrow-gap heterostructures. © 2012 IOP Publishing Ltd

Neuroanatomical correlates of the income-achievement gap.

PubMed

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

2015-06-01

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. In the research reported 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) than in students from lower-income backgrounds (n = 23), but cortical white-matter volume and total cortical surface area did not differ significantly between groups. Cortical thickness in all lobes of the brain was greater in students from higher-income than lower-income backgrounds. Greater cortical thickness, particularly in temporal and occipital lobes, was associated with better test performance. These results represent the first evidence that cortical thickness in higher- and lower-income students differs across broad swaths of the brain and that cortical thickness is related to scores on academic-achievement tests. © The Author(s) 2015.

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…

Conditions and phase shift of fluid resonance in narrow gaps of bottom mounted caissons

NASA Astrophysics Data System (ADS)

Zhu, Da-tong; Wang, Xing-gang; Liu, Qing-jun

2017-12-01

This paper studies the viscid and inviscid fluid resonance in gaps of bottom mounted caissons on the basis of the plane wave hypothesis and full wave model. The theoretical analysis and the numerical results demonstrate that the condition for the appearance of fluid resonance in narrow gaps is kh=(2 n+1)π ( n=0, 1, 2, 3, …), rather than kh= nπ ( n=0, 1, 2, 3, …); the transmission peaks in viscid fluid are related to the resonance peaks in the gaps. k and h stand for the wave number and the gap length. The combination of the plane wave hypothesis or the full wave model with the local viscosity model can accurately determine the heights and the locations of the resonance peaks. The upper bound for the appearance of fluid resonance in gaps is 2 b/ L<1 (2 b, grating constant; L, wave length) and the lower bound is h/ b≤1. The main reason for the phase shift of the resonance peaks is the inductive factors. The number of resonance peaks in the spectrum curve is dependent on the ratio of the gap length to the grating constant. The heights and the positions of the resonance peaks predicted by the present models agree well with the experimental data.

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…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velichko, A. V., E-mail: amalia.patane@nottingham.ac.uk, E-mail: anton.velychko@nottingham.ac.uk; Patanè, A., E-mail: amalia.patane@nottingham.ac.uk, E-mail: anton.velychko@nottingham.ac.uk; Makarovsky, O.

2015-01-12

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

Tunable transport gap in narrow bilayer graphene nanoribbons

PubMed Central

Yu, Woo Jong; Duan, Xiangfeng

2013-01-01

The lack of a bandgap makes bulk graphene unsuitable for room temperature transistors with a sufficient on/off current ratio. Lateral constriction of charge carriers in graphene nanostructures or vertical inversion symmetry breaking in bilayer graphene are two potential strategies to mitigate this challenge, but each alone is insufficient to consistently achieve a large enough on/off ratio (e.g. > 1000) for typical logic applications. Herein we report the combination of lateral carrier constriction and vertical inversion symmetry breaking in bilayer graphene nanoribbons (GNRs) to tune their transport gaps and improve the on/off ratio. Our studies demonstrate that the on/off current ratio of bilayer GNRs can be systematically increased upon applying a vertical electric field, to achieve a largest on/off current ratio over 3000 at room temperature. PMID:23409239

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

ERIC Educational Resources Information Center

Ladson-Billings, Gloria

2007-01-01

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

Subgroup Achievement and Gap Trends: New Hampshire

ERIC Educational Resources Information Center

Center on Education Policy, 2009

2009-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2013-11-01

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

The Importance of Physical Activity in Closing the Achievement Gap

ERIC Educational Resources Information Center

Burton, Laura J.; VanHeest, Jaci L.

2007-01-01

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

Solving the Achievement Gap: Overcoming the Structure of School Inequality

ERIC Educational Resources Information Center

Yeh, Stuart S.

2017-01-01

This book examines the cause of the student achievement gap, suggesting that the prevailing emphasis on socioeconomic factors, sociocultural influences, and teacher quality is misplaced. The cause of the achievement gap is not differences in parenting styles, or the economic advantages of middle-class parents, or differences in the quality of…

Narrowing the Achievement Gap in Science.

ERIC Educational Resources Information Center

Koba, Susan B.

1996-01-01

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

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…

Closing the Achievement Gap as Addressed in Student Support Programs

ERIC Educational Resources Information Center

Gordon, Vincent Hoover Adams, Jr.

2012-01-01

This research will focus on three components: (1) factors contributing to the achievement gap, (2) common errors made by policy makers with regard to school reform, and (3) recommendations to educators, policy makers, and parents on closing the achievement gap through results-based student support programs. Examples of each of the three components…

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…

Crystal Growth and Characterization of the Narrow-Band-Gap Semiconductors OsPn 2 (Pn = P, As, Sb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bugaris, Daniel E.; Malliakas, Christos D.; Shoemaker, Daniel P.

2014-09-15

Using metal fluxes, crystals of the binary osmium dipnictides OsPn(2) (Pn = P, As, Sb) have been grown for the first time. Single-crystal X-ray diffraction confirms that these compounds crystallize in the marcasite structure type with orthorhombic space group Pnnm. The structure is a three-dimensional framework of corner- and edge-sharing OsPn(6) octahedra, as well as [Pn(2)(-4)] anions. Raman spectroscopy shows the presence of PP single bonds, consistent with the presence of [Pn(2)(-4)] anions and formally Os4+ cations. Optical-band-gap and high-temperature electrical resistivity measurements indicate that these materials are narrow-band-gap semiconductors. The experimentally determined Seebeck coefficients reveal that nominally undoped OsP2more » and OsSb2 are n-type semiconductors, whereas OsAs2 is p-type. Electronic band structure using density functional theory calculations shows that these compounds are indirect narrow-band-gap semiconductors. The bonding p orbitals associated with the Pn(2) dimer are below the Fermi energy, and the corresponding antibonding states are above, consistent with a PnPn single bond. Thermopower calculations using Boltzmann transport theory and constant relaxation time approximation show that these materials are potentially good thermoelectrics, in agreement with experiment.« less

On-site SiH4 generator using hydrogen plasma generated in slit-type narrow gap

NASA Astrophysics Data System (ADS)

Takei, Norihisa; Shinoda, Fumiya; Kakiuchi, Hiroaki; Yasutake, Kiyoshi; Ohmi, Hiromasa

2018-06-01

We have been developing an on-site silane (SiH4) generator based on use of the chemical etching reaction between solid silicon (Si) and the high-density H atoms that are generated in high-pressure H2 plasma. In this study, we have developed a slit-type plasma source for high-efficiency SiH4 generation. High-density H2 plasma was generated in a narrow slit-type discharge gap using a 2.45 GHz microwave power supply. The plasma’s optical emission intensity distribution along the slit was measured and the resulting distribution was reflected by both the electric power distribution and the hydrogen gas flow. Because the Si etching rate strongly affects the SiH4 generation rate, the Si etching behavior was investigated with respect to variations in the experimental parameters. The weight etch rate increased monotonically with increasing input microwave power. However, the weight etch rate decreased with increasing H2 pressure and an increasing plasma gap. This reduction in the etch rate appears to be related to shrinkage of the plasma generation area because increased input power is required to maintain a constant plasma area with increasing H2 pressure and the increasing plasma gap. Additionally, the weight etch rate also increases with increasing H2 flow rate. The SiH4 generation rate of the slit-type plasma source was also evaluated using gas-phase Fourier transform infrared absorption spectroscopy and the material utilization efficiencies of both Si and the H2 gas for SiH4 gas formation were discussed. The main etch product was determined to be SiH4 and the developed plasma source achieved a SiH4 generation rate of 10 sccm (standard cubic centimeters per minute) at an input power of 900 W. In addition, the Si utilization efficiency exceeded 60%.

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…

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…

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

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 CuGaO 2 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-CuGaO 2 phase. Our calculations show that the β-CuGaO 2 structure is dynamically and mechanically stable. The energy band gap is confirmed to be direct at the Γ point ofmore » 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.« less

Teacher expectations, classroom context, and the achievement gap.

PubMed

McKown, Clark; Weinstein, Rhona S

2008-06-01

In two independent datasets with 1872 elementary-aged children in 83 classrooms, Studies 1 and 2 examined the role of classroom context in moderating the relationship between child ethnicity and teacher expectations. For Study 1 overall and Study 2 mixed-grade classrooms, in ethnically diverse classrooms where students reported high levels of differential teacher treatment (PDT) towards high and low achieving students, teacher expectations of European American and Asian American students were between .75 and 1.00 standard deviations higher than teacher expectations of African American and Latino students with similar records of achievement. In highly diverse low-PDT classrooms in Study 1 and highly diverse low-PDT mixed-grade classrooms in Study 2, teachers held similar expectations for all students with similar records of achievement. Study 3 estimated the contribution of teacher expectations to the year-end ethnic achievement gap in high- and low-bias classrooms. In high-bias classrooms, teacher expectancy effects accounted for an average of .29 and up to .38 standard deviations of the year-end ethnic achievement gap.

Judging Student Achievement: Why Getting the Right Data Matters. An MPR/NCEA Policy Brief

ERIC Educational Resources Information Center

Anderson, Sharon; Fowler, Donna; Klein, Steve

2005-01-01

States are engaged in serious efforts to raise student achievement, paying particular attention to narrowing the achievement gap between high- and low-performing students that has persisted in public schools for decades. The achievement gap is particularly troubling because, all too often, those at low achievement levels are minority, special…

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.)…

Closing the Achievement Gap: Views from Nine Schools.

ERIC Educational Resources Information Center

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

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

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.

High-Pressure Study of Perovskite-Like Organometal Halide: Band-Gap Narrowing and Structural Evolution of [NH 3 -(CH 2 ) 4 -NH 3 ]CuCl 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qian; Li, Shourui; Wang, Kai

Searching for nontoxic and stable perovskite-like alternatives to lead-based halide perovskites for photovoltaic application is one urgent issue in photoelectricity science. Such exploration inevitably requires an effective method to accurately control both the crystalline and electronic structures. This work applies high pressure to narrow the band gap of perovskite-like organometal halide, [NH 3-(CH 2) 4-NH 3]CuCl 4 (DABCuCl4), through the crystalline-structure tuning. The band gap keeps decreasing below ~12 GPa, involving the shrinkage and distortion of CuCl 4 2–. Inorganic distortion determines both band-gap narrowing and phase transition between 6.4 and 10.5 GPa, and organic chains function as the springmore » cushion, evidenced by the structural transition at ~0.8 GPa. The supporting function of organic chains protects DABCuCl 4 from phase transition and amorphization, which also contributes to the sustaining band-gap narrowing. This work combines crystal structure and macroscopic property together and offers new strategies for the further design and synthesis of hybrid perovskite-like alternatives.« less

School Counselors: Closing Achievement Gaps and Writing Results Reports

ERIC Educational Resources Information Center

Hartline, Julie; Cobia, Debra

2012-01-01

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

Minding and mending the gap: Social psychological interventions to reduce educational disparities.

PubMed

Spitzer, Brian; Aronson, Joshua

2015-03-01

Achievement gaps continue to garner a great deal of attention both in academic and in popular circles. Many students continue to struggle despite broad educational reforms aimed at narrowing these gaps in learning and performance. In this article, we review a number of social psychological interventions that show promise in reducing gaps in achievement, not by addressing structural barriers to achievement, but by helping students cope with threats to their identity that impair intellectual functioning and motivation. For example, interventions involving meditation, role models, emotional reappraisal, growth mindsets, imagining possible selves, self-affirmations, belongingness and cooperative learning have been shown to ameliorate threats to identity and raise achievement. We describe and evaluate these social psychological interventions. Many achievement gaps involve a psychological predicament: a threat to one's social identity or to one's sense of belonging. Students' implicit theories - how they mind the gap - can act as barriers to their success. By helping students cope with these threats, these theory-based interventions represent a genuine advance in the way schools may reduce gaps in achievement. These interventions show how students' educational success depends partly on fluid aspects of context - how tasks are framed, who else is in the room, or what they believe about intelligence. Because of this fluidity, these interventions may not work in all settings. Achievement gaps are ultimately caused by a variety of factors, both objective and subjective that produce inequality. The research reviewed here suggests that even without changes in objective barriers to success, brief psychological interventions can narrow what many see as intractable gaps in academic achievement. © 2015 The British Psychological Society.

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…

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…

Non-proximity resonant tunneling in multi-core photonic band gap fibers: An efficient mechanism for engineering highly-selective ultra-narrow band pass splitters

NASA Astrophysics Data System (ADS)

Florous, Nikolaos J.; Saitoh, Kunimasa; Murao, Tadashi; Koshiba, Masanori; Skorobogatiy, Maksim

2006-05-01

The objective of the present investigation is to demonstrate the possibility of designing compact ultra-narrow band-pass filters based on the phenomenon of non-proximity resonant tunneling in multi-core photonic band gap fibers (PBGFs). The proposed PBGF consists of three identical air-cores separated by two defected air-holes which act as highly-selective resonators. With a fine adjustment of the design parameters associated with the resonant-air-holes, phase matching at two distinct wavelengths can be achieved, thus enabling very narrow-band resonant directional coupling between the input and the two output cores. The validation of the proposed design is ensured with an accurate PBGF analysis based on finite element modal and beam propagation algorithms. Typical characteristics of the proposed device over a single polarization are: reasonable short coupling length of 2.7 mm, dual bandpass transmission response at wavelengths of 1.339 and 1.357 μm, with corresponding full width at half maximum bandwidths of 1.2 nm and 1.1 nm respectively, and a relatively high transmission of 95% at the exact resonance wavelengths. The proposed ultra-narrow band-pass filter can be employed in various applications such as all-fiber bandpass/bandstop filtering and resonant sensors.

Non-proximity resonant tunneling in multi-core photonic band gap fibers: An efficient mechanism for engineering highly-selective ultra-narrow band pass splitters.

PubMed

Florous, Nikolaos J; Saitoh, Kunimasa; Murao, Tadashi; Koshiba, Masanori; Skorobogatiy, Maksim

2006-05-29

The objective of the present investigation is to demonstrate the possibility of designing compact ultra-narrow band-pass filters based on the phenomenon of non-proximity resonant tunneling in multi-core photonic band gap fibers (PBGFs). The proposed PBGF consists of three identical air-cores separated by two defected air-holes which act as highly-selective resonators. With a fine adjustment of the design parameters associated with the resonant-air-holes, phase matching at two distinct wavelengths can be achieved, thus enabling very narrow-band resonant directional coupling between the input and the two output cores. The validation of the proposed design is ensured with an accurate PBGF analysis based on finite element modal and beam propagation algorithms. Typical characteristics of the proposed device over a single polarization are: reasonable short coupling length of 2.7 mm, dual bandpass transmission response at wavelengths of 1.339 and 1.357 mum, with corresponding full width at half maximum bandwidths of 1.2 nm and 1.1 nm respectively, and a relatively high transmission of 95% at the exact resonance wavelengths. The proposed ultra-narrow band-pass filter can be employed in various applications such as all-fiber bandpass/bandstop filtering and resonant sensors.

The Achievement Gap in Reading: Complex Causes, Persistent Issues, Possible Solutions

ERIC Educational Resources Information Center

Horowitz, Rosalind, Ed.; Samuels, S. Jay, Ed.

2017-01-01

In this volume prominent scholars, experts in their respective fields and highly skilled in the research they conduct, address educational and reading research from varied perspectives and address what it will take to close the achievement gap--with specific attention to reading. The achievement gap is redefined as a level at which all groups can…

Self-Regulation and the Income-Achievement Gap

ERIC Educational Resources Information Center

Evans, Gary W.; Rosenbaum, Jennifer

2008-01-01

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

Closing the Achievement Gap on ACT & SAT

ERIC Educational Resources Information Center

Anderson, David

2010-01-01

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

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…

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…

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…

Closing Achievement Gaps: Roles and Tasks of Elementary School Counselors

ERIC Educational Resources Information Center

Trusty, Jerry; Mellin, Elizabeth A.; Herbert, James T.

2008-01-01

Achievement gaps among racial-ethnic and socioeconomic status groups are an enduring, pervasive, and multifaceted phenomenon. Therefore, efforts aimed at understanding and addressing these gaps must be developmentally and environmentally broad, involving numerous school counselor roles and tasks, including leadership, advocacy, collaboration, and…

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

NASA Astrophysics Data System (ADS)

Mebane, Joyce Graham

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

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

NASA Astrophysics Data System (ADS)

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

2015-09-01

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

Low-temperature magnetotransport of the narrow-gap semiconductor FeSb2

NASA Astrophysics Data System (ADS)

Takahashi, H.; Okazaki, R.; Yasui, Y.; Terasaki, I.

2011-11-01

We present a study of the magnetoresistance and Hall effect in the narrow-gap semiconductor FeSb2 at low temperatures. Both the electrical and Hall resistivities show unusual magnetic field dependence in the low-temperature range where a large Seebeck coefficient was observed. By applying a two-carrier model, we find that the carrier concentration decreases from 1 down to 10-4 ppm/unit cell and the mobility increases from 2000 to 28 000 cm2/Vs with decreasing temperature from 30 down to 4 K. At lower temperatures, the magnetoresistive behavior drastically changes and a negative magnetoresistance is observed at 3 K. These low-temperature behaviors are reminiscent of the low-temperature magnetotransport observed in doped semiconductors such as As-doped Ge, which is well described by a weak-localization picture. We argue a detailed electronic structure in FeSb2 inferred from our observations.

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…

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

PubMed

2018-04-01

Reports an error in "Narrowing the transmission gap: A synthesis of three decades of research on intergenerational transmission of attachment" by Marije L. Verhage, Carlo Schuengel, Sheri Madigan, R. M. Pasco Fearon, Mirjam Oosterman, Rosalinda Cassibba, Marian J. Bakermans-Kranenburg and Marinus H. van IJzendoorn ( Psychological Bulletin , 2016[Apr], Vol 142[4], 337-366). In the article, there are errors in Table 7. The percentages of the attachment classifications do not add up to 100%. The corrected version of Table 7 is provided in the erratum. (The following abstract of the original article appeared in record 2015-55801-001.) Twenty years ago, meta-analytic results (k = 19) confirmed the association between caregiver attachment representations and child-caregiver attachment (Van IJzendoorn, 1995). A test of caregiver sensitivity as the mechanism behind this intergenerational transmission showed an intriguing "transmission gap." Since then, the intergenerational transmission of attachment and the transmission gap have been studied extensively, and now extend to diverse populations from all over the globe. Two decades later, the current review revisited the effect sizes of intergenerational transmission, the heterogeneity of the transmission effects, and the size of the transmission gap. Analyses were carried out with a total of 95 samples (total N = 4,819). All analyses confirmed intergenerational transmission of attachment, with larger effect sizes for secure-autonomous transmission (r = .31) than for unresolved transmission (r = .21), albeit with significantly smaller effect sizes than 2 decades earlier (r = .47 and r = .31, respectively). Effect sizes were moderated by risk status of the sample, biological relatedness of child-caregiver dyads, and age of the children. Multivariate moderator analyses showed that unpublished and more recent studies had smaller effect sizes than published and older studies. Path analyses showed that the transmission could not

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…

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…

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…

Enhancing catalytic activity by narrowing local energy gaps--X-ray studies of a manganese water oxidation catalyst.

PubMed

Xiao, Jie; Khan, Munirah; Singh, Archana; Suljoti, Edlira; Spiccia, Leone; Aziz, Emad F

2015-03-01

Changes in the local electronic structure of the Mn 3d orbitals of a Mn catalyst derived from a dinuclear Mn(III) complex during the water oxidation cycle were investigated ex situ by X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) analyses. Detailed information about the Mn 3d orbitals, especially the local HOMO-LUMO gap on Mn sites revealed by RIXS analyses, indicated that the enhancement in catalytic activity (water oxidation) originated from the narrowing of the local HOMO-LUMO gap when electrical voltage and visible light illumination were applied simultaneously to the Mn catalytic system. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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…

Racial and Gender Gaps in Academic Achievement. Report Summary.

ERIC Educational Resources Information Center

Dulaney, Chuck; Banks, Karen

This report summarizes the level of academic achievement, and the extent of racial and gender gaps in that achievement, of students in North Carolina's Wake County Public School System (WCPSS). The comparison was conducted using 1993 End-of-Grade (EOG) tests; low income group EOG test performance; 1993 writing tests and high school writing…

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

PubMed

Crook, Stephen R; Evans, Gary W

2014-01-01

The pervasive income-achievement gap has been attributed in part to deficiencies in executive functioning (EF). The development of EF is related to children's planning ability, an aspect of development that has received little attention. Longitudinal data from the National Institute of Child Health and Human Development study of early child care show that early childhood poverty (1 and 24 months) is significantly related to fifth grade, math, and reading achievement (n = 1,009). The ability to plan in Grade 3, indexed by the Tower of Hanoi task, mediates the income-achievement gap in math and to a lesser extent in reading. IQ was incorporated as a statistical control throughout. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

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…

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…

Black-white achievement gap and family wealth.

PubMed

Yeung, W Jean; Conley, Dalton

2008-01-01

This article examines the extent to which family wealth affects the Black-White test score gap for young children based on data from the Panel Study of Income Dynamics (aged 3-12). This study found little evidence that wealth mediated the Black-White test scores gaps, which were eliminated when child and family demographic covariates were held constant. However, family wealth had a stronger association with cognitive achievement of school-aged children than that of preschoolers and a stronger association with school-aged children's math than on their reading scores. Liquid assets, particularly holdings in stocks or mutual funds, were positively associated with school-aged children's test scores. Family wealth was associated with a higher quality home environment, better parenting behavior, and children's private school attendance.

The Achievement Gap and the Discipline Gap: Two Sides of the Same Coin?

ERIC Educational Resources Information Center

Gregory, Anne; Skiba, Russell J.; Noguera, Pedro A.

2010-01-01

The gap in achievement across racial and ethnic groups has been a focus of education research for decades, but the disproportionate suspension and expulsion of Black, Latino, and American Indian students has received less attention. This article synthesizes research on racial and ethnic patterns in school sanctions and considers how…

Standing in the Gap: Theory and Practice Impacting Educational Opportunity and Achievement Gaps

ERIC Educational Resources Information Center

Beard, Karen Stansberry

2018-01-01

This case study is the first known employing flow in educational administration in the United States. Using Csikszentmihalyi's flow theory and Dantley's purpose-driven leadership, an administrator's practices were examined with respect to two guiding questions: (a) is purposefulness integral to closing extant gaps in achievement, and (b) are the…

Reducing the racial achievement gap: a social-psychological intervention.

PubMed

Cohen, Geoffrey L; Garcia, Julio; Apfel, Nancy; Master, Allison

2006-09-01

Two randomized field experiments tested a social-psychological intervention designed to improve minority student performance and increase our understanding of how psychological threat mediates performance in chronically evaluative real-world environments. We expected that the risk of confirming a negative stereotype aimed at one's group could undermine academic performance in minority students by elevating their level of psychological threat. We tested whether such psychological threat could be lessened by having students reaffirm their sense of personal adequacy or "self-integrity." The intervention, a brief in-class writing assignment, significantly improved the grades of African American students and reduced the racial achievement gap by 40%. These results suggest that the racial achievement gap, a major social concern in the United States, could be ameliorated by the use of timely and targeted social-psychological interventions.

Preferential Charge Generation at Aggregate Sites in Narrow Band Gap Infrared Photoresponsive Polymer Semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sulas, Dana B.; London, Alexander E.; Huang, Lifeng

Infrared organic photodetector materials are investigated using transient absorption spectroscopy, demonstrating that ultrafast charge generation assisted by polymer aggregation is essential to compensate for the energy gap law, which dictates that excited state lifetimes decrease as the band gap narrows. Short sub–picosecond singlet exciton lifetimes are measured in a structurally related series of infrared–absorbing copolymers that consist of alternating cyclopentadithiophene electron–rich “push” units and strong electron–deficient “pull” units, including benzothiadiazole, benzoselenadiazole, pyridalselenadiazole, or thiadiazoloquinoxaline. While the ultrafast lifetimes of excitons localized on individual polymer chains suggest that charge carrier generation will be inefficient, high detectivity for polymer:PC 71BM infrared photodetectorsmore » is measured in the 0.6 < λ < 1.5 µm range. The photophysical processes leading to charge generation are investigated by performing a global analysis on transient absorption data of blended polymer:PC 71BM films. In these blends, charge carriers form primarily at polymer aggregate sites on the ultrafast time scale (within our instrument response), leaving quickly decaying single–chain excitons unquenched. Lastly, the results have important implications for the further development of organic infrared optoelectronic devices, where targeting processes such as excited state delocalization over aggregates may be necessary to mitigate losses to ultrafast exciton decay as materials with even lower band gaps are developed.« less

Preferential Charge Generation at Aggregate Sites in Narrow Band Gap Infrared Photoresponsive Polymer Semiconductors

DOE PAGES

Sulas, Dana B.; London, Alexander E.; Huang, Lifeng; ...

2018-02-13

Infrared organic photodetector materials are investigated using transient absorption spectroscopy, demonstrating that ultrafast charge generation assisted by polymer aggregation is essential to compensate for the energy gap law, which dictates that excited state lifetimes decrease as the band gap narrows. Short sub–picosecond singlet exciton lifetimes are measured in a structurally related series of infrared–absorbing copolymers that consist of alternating cyclopentadithiophene electron–rich “push” units and strong electron–deficient “pull” units, including benzothiadiazole, benzoselenadiazole, pyridalselenadiazole, or thiadiazoloquinoxaline. While the ultrafast lifetimes of excitons localized on individual polymer chains suggest that charge carrier generation will be inefficient, high detectivity for polymer:PC 71BM infrared photodetectorsmore » is measured in the 0.6 < λ < 1.5 µm range. The photophysical processes leading to charge generation are investigated by performing a global analysis on transient absorption data of blended polymer:PC 71BM films. In these blends, charge carriers form primarily at polymer aggregate sites on the ultrafast time scale (within our instrument response), leaving quickly decaying single–chain excitons unquenched. Lastly, the results have important implications for the further development of organic infrared optoelectronic devices, where targeting processes such as excited state delocalization over aggregates may be necessary to mitigate losses to ultrafast exciton decay as materials with even lower band gaps are developed.« less

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…

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…

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.

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…

School Segregation and Racial Academic Achievement Gaps. CEPA Working Paper No. 15-12

ERIC Educational Resources Information Center

Reardon, Sean F.

2015-01-01

Although it is clear that racial segregation is linked to academic achievement gaps, the mechanisms underlying this link have been debated since Coleman published his eponymous 1966 report. In this paper, I examine 16 distinct measures of segregation to determine which is most strongly associated with academic achievement gaps. I find very clear…

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…

Narrowing the Academic Achievement Gap among High School Latino Students through Parental Involvement

ERIC Educational Resources Information Center

Parry, Douglas L.

2010-01-01

The low academic achievement among Latino students in many inner city high schools leads to higher failure, dropout, and absenteeism rates, as well as lower standardized test scores and graduation rates. The purpose of this study was to explore whether Latino parental attitudes toward and perceptions, level of, and form of involvement may be…

Narrow Band Gap Conjugated Polyelectrolytes.

PubMed

Cui, Qiuhong; Bazan, Guillermo C

2018-01-16

Two essential structural elements define a class of materials called conjugated polyelectrolytes (CPEs). The first is a polymer framework with an electronically delocalized, π-conjugated structure. This component allows one to adjust desirable optical and electronic properties, for example the range of wavelengths absorbed, emission quantum yields, electron affinity, and ionization potential. The second defining feature is the presence of ionic functionalities, which are usually linked via tethers that can modulate the distance of the charged groups relative to the backbone. These ionic groups render CPEs distinct relative to their neutral conjugated polymer counterparts. Solubility in polar solvents, including aqueous media, is an immediately obvious difference. This feature has enabled the development of optically amplified biosensor protocols and the fabrication of multilayer organic semiconductor devices through deposition techniques using solvents with orthogonal properties. Important but less obvious potential advantages must also be considered. For example, CPE layers have been used to introduce interfacial dipoles and thus modify the effective work function of adjacent electrodes. One can thereby modulate the barriers for charge injection into semiconductor layers and improve the device efficiencies of organic light-emitting diodes and solar cells. With a hydrophobic backbone and hydrophilic ionic sites, CPEs can also be used as dispersants for insoluble materials. Narrow band gap CPEs (NBGCPEs) have been studied only recently. They contain backbones that comprise electron-rich and electron-poor fragments, a combination that leads to intramolecular charge transfer excited states and enables facile oxidation and reduction. One particularly interesting combination is NBGCPEs with anionic sulfonate side groups, for which spontaneous self-doping in aqueous media is observed. That no such doping is observed with cationic NBGCPEs indicates that the interplay

Closing the Achievement Gap: Rural Schools. CSR Connection.

ERIC Educational Resources Information Center

Williams, Doris Terry

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

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…

Subgroup Achievement and Gap Trends: New Hampshire, 2010

ERIC Educational Resources Information Center

Center on Education Policy, 2010

2010-01-01

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

Superconductivity in the Narrow Gap Semiconductor RbBi 11/3Te 6

DOE PAGES

Malliakas, Christos D.; Chung, Duck Young; Claus, Helmut; ...

2016-10-16

Superconductivity was discovered in the layered compound RbBi 11/3Te 6, featuring Bi vacancies and a narrow band gap of 0.25(2) eV at room temperature. In addition, a sharp superconducting transition at similar to 3.2 K was observed in polycrystalline ingots. The superconducting volume fraction of oriented single crystals is almost 100%, confirming bulk superconductivity. Systematic Se and Sb substitutions in RbBi 11/3-ySb ySe xTe 6-x, revealed a dependence of the superconducting transition on composition that can increase the T c up to similar to 10%. The RbBi 11/3Te 6 system is the first member of the new homologous series Rb[Bimore » 2n+11/3Te 3n+6] with infinite Bi 2Te 3-like layers. Lastly, the large degree of chemical tunability of the electronic structure of the homology via doping and/or substitution gives rise to a new family of superconductors.« less

Gazing Past the Gaps: A Growth-Based Assessment of the Mathematics Achievement of Black Girls

ERIC Educational Resources Information Center

Young, Jemimah L.; Young, Jamaal R.; Capraro, Robert M.

2018-01-01

The purpose of this study was to proffer the idea to "gaze" past gender and racial achievement gaps by providing a growth-based assessment of the achievement of Black girls. The study aims to elucidate how alternatives to traditional achievement gap analyses can yield information relevant to addressing classroom challenges. This…

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…

Observations and predictability of gap winds in a steep, narrow, fire-prone canyon in central Idaho, USA

NASA Astrophysics Data System (ADS)

Wagenbrenner, N. S.; Forthofer, J.; Gibson, C.; Lamb, B. K.

2017-12-01

Frequent strong gap winds were measured in a deep, steep, wildfire-prone river canyon of central Idaho, USA during July-September 2013. Analysis of archived surface pressure data indicate that the gap wind events were driven by regional scale surface pressure gradients. The events always occurred between 0400 and 1200 LT and typically lasted 3-4 hours. The timing makes these events particularly hazardous for wildland firefighting applications since the morning is typically a period of reduced fire activity and unsuspecting firefighters could be easily endangered by the onset of strong downcanyon winds. The gap wind events were not explicitly forecast by operational numerical weather prediction (NWP) models due to the small spatial scale of the canyon ( 1-2 km wide) compared to the horizontal resolution of operational NWP models (3 km or greater). Custom WRF simulations initialized with NARR data were run at 1 km horizontal resolution to assess whether higher resolution NWP could accurately simulate the observed gap winds. Here, we show that the 1 km WRF simulations captured many of the observed gap wind events, although the strength of the events was underpredicted. We also present evidence from these WRF simulations which suggests that the Salmon River Canyon is near the threshold of WRF-resolvable terrain features when the standard WRF coordinate system and discretization schemes are used. Finally, we show that the strength of the gap wind events can be predicted reasonably well as a function of the surface pressure gradient across the gap, which could be useful in the absence of high-resolution NWP. These are important findings for wildland firefighting applications in narrow gaps where routine forecasts may not provide warning for wind effects induced by high-resolution terrain features.

Theory of g-factor enhancement in narrow-gap quantum well heterostructures.

PubMed

Krishtopenko, S S; Gavrilenko, V I; Goiran, M

2011-09-28

We report on the study of the exchange enhancement of the g-factor in the two-dimensional (2D) electron gas in n-type narrow-gap semiconductor heterostructures. Our approach is based on the eight-band k⋅p Hamiltonian and takes into account the band nonparabolicity, the lattice deformation, the spin-orbit coupling and the Landau level broadening in the δ-correlated random potential model. Using the 'screened' Hartree-Fock approximation we demonstrate that the exchange g-factor enhancement not only shows maxima at odd values of Landau level filling factors but, due to the conduction band nonparabolicity, persists at even filling factor values as well. The magnitude of the exchange enhancement, the amplitude and the shape of the g-factor oscillations are determined by both the screening of the electron-electron interaction and the Landau level width. The 'enhanced' g-factor values calculated for the 2D electron gas in InAs/AlSb quantum well heterostructures are compared with our earlier experimental data and with those obtained by Mendez et al (1993 Phys. Rev. B 47 13937) in magnetic fields up to 30 T.

Unfulfilled Potential: High-Achieving Minority Students and the High School Achievement Gap in Math

ERIC Educational Resources Information Center

Kotok, Stephen

2017-01-01

This study uses multilevel modeling to examine a subset of the highest performing 9th graders and explores the extent that achievement gaps in math widen for high performing African American and Latino students and their high performing White and Asian peers during high school. Using nationally representative data from the High School Longitudinal…

Can Professional Development Programs Help Close the Achievement Gap?

ERIC Educational Resources Information Center

Brahler, C. Jayne; Bainbridge, William L.; Stevens, Margaret

2004-01-01

This paper explores the question of whether it is possible to design professional development programs for teachers that can significantly improve student test results and reduce the achievement gap for students. The Dayton (Ohio) Foundation and the Montgomery County (Ohio) Educational Service Center, sponsors of The Miami Valley Teacher/…

High-Performance Polymer Solar Cell with Single Active Material of Fully Conjugated Block Copolymer Composed of Wide-Band gap Donor and Narrow-Band gap Acceptor Blocks.

PubMed

Lee, Ji Hyung; Park, Chang Geun; Kim, Aesun; Kim, Hyung Jong; Kim, Youngseo; Park, Sungnam; Cho, Min Ju; Choi, Dong Hoon

2018-06-06

We synthesized a novel fully conjugated block copolymer, P3, in which a wide-band gap donor block (P1) was connected to a narrow-band gap acceptor block (P2). As P3 contains P1 block with a wide bandgap and P2 block with a narrow bandgap, it exhibits a very wide complementary absorption. Transient photoluminescence measurement using P3 dilute solution demonstrated intramolecular charge transfer between the P1 block and the P2 block, which was not observed in a P1/P2 blend solution. A P3 thin film showed complete PL quenching because the photoinduced inter-/intramolecular charge transfer states were effectively formed. This phenomenon can play an important role in the photovoltaic properties of P3-based polymer solar cells. A single active material polymer solar cell (SAMPSC) fabricated from P3 alone exhibited a high power conversion efficiency (PCE) of 3.87% with a high open-circuit voltage of 0.93 V and a short-circuit current of 8.26 mA/cm 2 , demonstrating a much better performance than a binary P1-/P2-based polymer solar cell (PCE = 1.14%). This result facilitates the possible improvement of the photovoltaic performance of SAMPSCs by inducing favorable nanophase segregation between p- and n blocks. In addition, owing to the high morphological stability of the block copolymer, excellent shelf-life was observed in a P3-based SAMPSC compared with a P1/P2-based PSC.

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

ERIC Educational Resources Information Center

Welch-Ross, Melissa

2010-01-01

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

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…

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)…

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…

The Global Increase in the Socioeconomic Achievement Gap, 1964-2015. CEPA Working Paper No. 17-04

ERIC Educational Resources Information Center

Chmielewski, Anna K.

2017-01-01

The existence of a "socioeconomic achievement gap"--a disparity in academic achievement between students from high- and low-socioeconomic status (SES) backgrounds--is well-known in educational research. The SES achievement gap has been documented across a wide range of countries. What is unknown in most countries is whether the SES…

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.…

State Test Score Trends through 2008-09, Part 2: Slow and Uneven Progress in Narrowing Gaps

ERIC Educational Resources Information Center

Kober, Nancy; Chudowsky, Naomi; Chudowsky, Victor

2010-01-01

After eight years of implementing the federal No Child Left Behind Act (NCLB) and other school reforms, how much progress have states, school districts, and schools made in raising achievement for students from all backgrounds and closing achievement gaps based on race, ethnicity, income, and gender? To help answer this question, the Center on…

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…

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…

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…

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.

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

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

PubMed

Becker, Bronwyn E; Luthar, Suniya S

2002-01-01

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

Large-scale transport across narrow gaps in rod bundles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guellouz, M.S.; Tavoularis, S.

1995-09-01

Flow visualization and how-wire anemometry were used to investigate the velocity field in a rectangular channel containing a single cylindrical rod, which could be traversed on the centreplane to form gaps of different widths with the plane wall. The presence of large-scale, quasi-periodic structures in the vicinity of the gap has been demonstrated through flow visualization, spectral analysis and space-time correlation measurements. These structures are seen to exist even for relatively large gaps, at least up to W/D=1.350 (W is the sum of the rod diameter, D, and the gap width). The above measurements appear to compatible with the fieldmore » of a street of three-dimensional, counter-rotating vortices, whose detailed structure, however, remains to be determined. The convection speed and the streamwise spacing of these vortices have been determined as functions of the gap size.« less

Optimizations for optical velocity measurements in narrow gaps

NASA Astrophysics Data System (ADS)

Schlüßler, Raimund; Blechschmidt, Christian; Czarske, Jürgen; Fischer, Andreas

2013-09-01

Measuring the flow velocity in small gaps or near a surface with a nonintrusive optical measurement technique is a challenging measurement task, as disturbing light reflections from the surface appear. However, these measurements are important, e.g., in order to understand and to design the leakage flow in the tip gap between the rotor blade end face and the housing of a turbomachine. Hence, methods to reduce the interfering light power and to correct measurement errors caused by it need to be developed and verified. Different alternatives of minimizing the interfering light power for optical flow measurements in small gaps are presented. By optimizing the beam shape of the applied illumination beam using a numerical diffraction simulation, the interfering light power is reduced by up to a factor of 100. In combination with a decrease of the reflection coefficient of the rotor blade surface, an additional reduction of the interfering light power below the used scattered light power is possible. Furthermore, a correction algorithm to decrease the measurement uncertainty of disturbed measurements is derived. These improvements enable optical three-dimensional three-component flow velocity measurements in submillimeter gaps or near a surface.

Searching for the Golden Model of Education: Cross-National Analysis of Math Achievement

PubMed Central

Bodovski, Katerina; Byun, Soo-yong; Chykina, Volha; Chung, Hee Jin

2017-01-01

We utilized four waves of TIMSS data in addition to the information we have collected on countries’ educational systems to examine whether different degrees of standardization, differentiation, proportion of students in private schools and governmental spending on education influence students’ math achievement, its variation and socioeconomic status (SES) gaps in math achievement. Findings: A higher level of standardization of educational systems was associated with higher average math achievement. Greater expenditure on education (as % of total government expenditure) was associated with a lower level of dispersion of math achievement and smaller SES gaps in math achievement. Wealthier countries exhibited higher average math achievement and a narrower variation. Higher income inequality (measured by Gini index) was associated with a lower average math achievement and larger SES gaps. Further, we found that higher level of standardization alleviates the negative effects of differentiation in the systems with more rigid tracking. PMID:29151667

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

ERIC Educational Resources Information Center

Lai, Fang

2010-01-01

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

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

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

PubMed

Skinner, Mark W

2012-07-01

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

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

ERIC Educational Resources Information Center

Simms, Kathryn

2012-01-01

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

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…

Increased structure and active learning reduce the achievement gap in introductory biology.

PubMed

Haak, David C; HilleRisLambers, Janneke; Pitre, Emile; Freeman, Scott

2011-06-03

Science, technology, engineering, and mathematics instructors have been charged with improving the performance and retention of students from diverse backgrounds. To date, programs that close the achievement gap between students from disadvantaged versus nondisadvantaged educational backgrounds have required extensive extramural funding. We show that a highly structured course design, based on daily and weekly practice with problem-solving, data analysis, and other higher-order cognitive skills, improved the performance of all students in a college-level introductory biology class and reduced the achievement gap between disadvantaged and nondisadvantaged students--without increased expenditures. These results support the Carnegie Hall hypothesis: Intensive practice, via active-learning exercises, has a disproportionate benefit for capable but poorly prepared students.

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…

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,…

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…

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…

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…

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…

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)…

The Mediating Effect of ICT Usage on the Relationship between Students' Socioeconomic Status and Achievement

ERIC Educational Resources Information Center

Chiao, Chi; Chiu, Chiung-Hui

2018-01-01

To find out if information and communication technology (ICT) could narrow the achievement gaps among students caused by variations in their socioeconomic status, this study examines the mediating mechanism of ICT use between students' socioeconomic status (SES) and achievement. Data from the 2012 East Asia Program for International Student…

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…

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.

Values Affirmation Intervention Reduces Achievement Gap between Underrepresented Minority and White Students in Introductory Biology Classes

PubMed Central

Jordt, Hannah; Eddy, Sarah L.; Brazil, Riley; Lau, Ignatius; Mann, Chelsea; Brownell, Sara E.; King, Katherine; Freeman, Scott

2017-01-01

Achievement gaps between underrepresented minority (URM) students and their white peers in college science, technology, engineering, and mathematics classrooms are persistent across many white-majority institutions of higher education. Attempts to reduce this phenomenon of underperformance through increasing classroom structure via active learning have been partially successful. In this study, we address the hypothesis that the achievement gap between white and URM students in an undergraduate biology course has a psychological and emotional component arising from stereotype threat. Specifically, we introduced a values affirmation exercise that counters stereotype threat by reinforcing a student’s feelings of integrity and self-worth in three iterations of an intensive active-learning college biology course. On average, this exercise reduced the achievement gap between URM and white students who entered the course with the same incoming grade point average. This result suggests that achievement gaps resulting from the underperformance of URM students could be mitigated by providing students with a learning environment that removes psychological and emotional impediments of performance through short psychosocial interventions. PMID:28710060

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…

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…

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…

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…

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

An Exceptionally Narrow Band-Gap (∼4 eV) Silicate Predicted in the Cubic Perovskite Structure: BaSiO3.

PubMed

Hiramatsu, Hidenori; Yusa, Hitoshi; Igarashi, Ryo; Ohishi, Yasuo; Kamiya, Toshio; Hosono, Hideo

2017-09-05

The electronic structures of 35 A 2+ B 4+ O 3 ternary cubic perovskite oxides, including their hypothetical chemical compositions, were calculated by a hybrid functional method with the expectation that peculiar electronic structures and unique carrier transport properties suitable for semiconductor applications would be hidden in high-symmetry cubic perovskite oxides. We found unique electronic structures of Si-based oxides (A = Mg, Ca, Sr, and Ba, and B = Si). In particular, the unreported cubic BaSiO 3 has a very narrow band gap (4.1 eV) compared with conventional nontransition-metal silicates (e.g., ∼9 eV for SiO 2 and the calculated value of 7.3 eV for orthorhombic BaSiO 3 ) and a small electron effective mass (0.3m 0 , where m 0 is the free electron rest mass). The narrow band gap is ascribed to the nonbonding state of Si 3s and the weakened Madelung potential. The existence of the predicted cubic perovskite structure of BaSiO 3 was experimentally verified by applying a high pressure of 141 GPa. The present finding indicates that it could be possible to develop a new transparent oxide semiconductor of earth abundant silicates if the symmetry of its crystal structure is appropriately chosen. Cubic BaSiO 3 is a candidate for high-performance oxide semiconductors if this phase can be stabilized at room temperature and ambient pressure.

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…

The Dialectical Problematic of Resolving the Black-White Academic Achievement Gap and Climate Change

ERIC Educational Resources Information Center

Mocombe, Paul C.

2018-01-01

In this article, I argue that resolving the Black-White academic achievement gap is incompatible with the emerging issues of global climate change. That is, solutions (equitable funding of schools and resources, school integration movements, and after-school and mentoring programs) for closing the gap in order so that Blacks in America and…

Behaviors of Teachers and Their Students in Schools with and without an Achievement Gap: An Observational Study

ERIC Educational Resources Information Center

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

2017-01-01

This research shares findings from a year-long observational study to determine if there were significant differences in the identified behaviors of teachers and students in fourth and seventh grade classrooms in schools with an achievement gap versus those with no achievement gap. Specific research questions addressed types of instructional…

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…

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.

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…

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

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)…

Sustainability of a Narrowed Achievement Gap: A Case Study

ERIC Educational Resources Information Center

Titus, Michael Richard

2010-01-01

Schools with student populations comprised predominantly of students of color, socioeconomically disadvantaged, and English Learners have traditionally been relegated to subpar educational opportunities. The accountability of the No Child Left Behind Act prodded schools to reexamine their instructional practices and implement more effective means…

High-Pressure Band-Gap Engineering in Lead-Free Cs 2 AgBiBr 6 Double Perovskite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qian; Wang, Yonggang; Pan, Weicheng

Novel inorganic lead-free double perovskites with improved stability are regarded as alternatives to state-of-art hybrid lead halide perovskites in photovoltaic devices. The recently discovered Cs2AgBiBr6 double perovskite exhibits attractive optical and electronic features, making it promising for various optoelectronic applications. However, its practical performance is hampered by the large band gap. In this work, remarkable band gap narrowing of Cs2AgBiBr6 is, for the first time, achieved on inorganic photovoltaic double perovskites through high pressure treatments. Moreover, the narrowed band gap is partially retainable after releasing pressure, promoting its optoelectronic applications. This work not only provides novel insights into the structure–propertymore » relationship in lead-free double perovskites, but also offers new strategies for further development of advanced perovskite devices.« less

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…

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…

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…

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…

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-…

Second-harmonic generation at angular incidence in a negative-positive index photonic band-gap structure.

PubMed

D'Aguanno, Giuseppe; Mattiucci, Nadia; Scalora, Michael; Bloemer, Mark J

2006-08-01

In the spectral region where the refractive index of the negative index material is approximately zero, at oblique incidence, the linear transmission of a finite structure composed of alternating layers of negative and positive index materials manifests the formation of a new type of band gap with exceptionally narrow band-edge resonances. In particular, for TM-polarized (transverse magnetic) incident waves, field values that can be achieved at the band edge may be much higher compared to field values achievable in standard photonic band-gap structures. We exploit the unique properties of these band-edge resonances for applications to nonlinear frequency conversion, second-harmonic generation, in particular. The simultaneous availability of high field localization and phase matching conditions may be exploited to achieve second-harmonic conversion efficiencies far better than those achievable in conventional photonic band-gap structures. Moreover, we study the role played by absorption within the negative index material, and find that the process remains efficient even for relatively high values of the absorption coefficient.

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…

Addressing Achievement Gaps: The Language Acquisition and Educational Achievement of English-Language Learners. ETS Policy Notes. Volume 16, Number 2, Summer 2008

ERIC Educational Resources Information Center

McBride, Amanda

2008-01-01

The eighth "ETS Addressing Achievement Gaps Symposium" provided a public forum for educators, policymakers, and researchers to forge productive relationships that will advance their efforts to enhance the educational achievement of America's five million English-language learners (ELLs). The conference was held at ETS world headquarters in…

Band Edge Dynamics and Multiexciton Generation in Narrow Band Gap HgTe Nanocrystals.

PubMed

Livache, Clément; Goubet, Nicolas; Martinez, Bertille; Jagtap, Amardeep; Qu, Junling; Ithurria, Sandrine; Silly, Mathieu G; Dubertret, Benoit; Lhuillier, Emmanuel

2018-04-11

Mercury chalcogenide nanocrystals and especially HgTe appear as an interesting platform for the design of low cost mid-infrared (mid-IR) detectors. Nevertheless, their electronic structure and transport properties remain poorly understood, and some critical aspects such as the carrier relaxation dynamics at the band edge have been pushed under the rug. Some of the previous reports on dynamics are setup-limited, and all of them have been obtained using photon energy far above the band edge. These observations raise two main questions: (i) what are the carrier dynamics at the band edge and (ii) should we expect some additional effect (multiexciton generation (MEG)) as such narrow band gap materials are excited far above the band edge? To answer these questions, we developed a high-bandwidth setup that allows us to understand and compare the carrier dynamics resonantly pumped at the band edge in the mid-IR and far above the band edge. We demonstrate that fast (>50 MHz) photoresponse can be obtained even in the mid-IR and that MEG is occurring in HgTe nanocrystal arrays with a threshold around 3 times the band edge energy. Furthermore, the photoresponse can be effectively tuned in magnitude and sign using a phototransistor configuration.

Gender Gap Linked to Differential Socialization for High-Achieving Senior Mathematics Students.

ERIC Educational Resources Information Center

Campbell, James R.; Beaudry, Jeffrey S.

1998-01-01

Examined whether 11th-grade girls and boys enrolled in advanced mathematics courses nationwide were socialized in similar ways, using Campbell's differential socialization paradigm. Results uncovered a gender gap favoring boys. Self-imposed pressure and persistence had important direct effects on achievement. Self-concept had important direct…

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…

Values Affirmation Intervention Reduces Achievement Gap between Underrepresented Minority and White Students in Introductory Biology Classes.

PubMed

Jordt, Hannah; Eddy, Sarah L; Brazil, Riley; Lau, Ignatius; Mann, Chelsea; Brownell, Sara E; King, Katherine; Freeman, Scott

2017-01-01

Achievement gaps between underrepresented minority (URM) students and their white peers in college science, technology, engineering, and mathematics classrooms are persistent across many white-majority institutions of higher education. Attempts to reduce this phenomenon of underperformance through increasing classroom structure via active learning have been partially successful. In this study, we address the hypothesis that the achievement gap between white and URM students in an undergraduate biology course has a psychological and emotional component arising from stereotype threat. Specifically, we introduced a values affirmation exercise that counters stereotype threat by reinforcing a student's feelings of integrity and self-worth in three iterations of an intensive active-learning college biology course. On average, this exercise reduced the achievement gap between URM and white students who entered the course with the same incoming grade point average. This result suggests that achievement gaps resulting from the underperformance of URM students could be mitigated by providing students with a learning environment that removes psychological and emotional impediments of performance through short psychosocial interventions. © 2017 H. Jordt et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Band gap narrowing in n-type and p-type 3C-, 2H-, 4H-, 6H-SiC, and Si

NASA Astrophysics Data System (ADS)

Persson, C.; Lindefelt, U.; Sernelius, B. E.

1999-10-01

Doping-induced energy shifts of the conduction band minimum and the valence band maximum have been calculated for n-type and p-type 3C-, 2H-, 4H-, 6H-SiC, and Si. The narrowing of the fundamental band gap and of the optical band gap are presented as functions of ionized impurity concentration. The calculations go beyond the common parabolic treatments of the ground state energy dispersion by using energy dispersion and overlap integrals from band structure calculations. The nonparabolic valence band curvatures influence strongly the energy shifts especially in p-type materials. The utilized method is based on a zero-temperature Green's function formalism within the random phase approximation with local field correction according to Hubbard. We have parametrized the shifts of the conduction and the valence bands and made comparisons with recently published results from a semi-empirical model.

Closing achievement gaps with a utility-value intervention: Disentangling race and social class.

PubMed

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

2016-11-01

Many college students abandon their goal of completing a degree in science, technology, engineering, or math (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 2 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 4 semesters of an introductory biology course (N = 1,040), 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 continuing generation (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 intersectionality in 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. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

[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

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.…

An Exploration of Community Capital, Student Composition of Schools, and Achievement Gaps

ERIC Educational Resources Information Center

Wang, Chuang; Algozzine, Bob; Porfeli, Erik

2015-01-01

"Closing the achievement gap" (i.e. reducing differences in performance across racial and ethnic groups) has been the rallying cry and holy grail for reform efforts in American education for some time. In addition to influences associated with school and teacher factors, researchers have now turned their attention to characteristics in…

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

ERIC Educational Resources Information Center

Herron-McCoy, La-Monica

2009-01-01

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

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…

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

PubMed Central

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

2013-01-01

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

Close the Gap: A Multiple Case Study about the Decision-Making Process of Administrators in Ohio Districts

ERIC Educational Resources Information Center

Guthrie, Tammy Reutzel

2017-01-01

Research has identified evidenced-based practices and programs that are successful for increasing the learning outcomes of students with disabilities which in turn helps narrow the achievement gap between the student subgroup and non-disabled peers. Employing the identified practices has produced inconsistent results and led to a closer…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Liefeng, E-mail: fengliefeng@tju.edu.cn, E-mail: lihongru@nankai.edu.cn; Yang, Xiufang; Wang, Cunda

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}more » 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.« less

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…

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…

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,…

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…

Acceptor-modulated optical enhancements and band-gap narrowing in ZnO thin films

NASA Astrophysics Data System (ADS)

Hassan, Ali; Jin, Yuhua; Irfan, Muhammad; Jiang, Yijian

2018-03-01

Fermi-Dirac distribution for doped semiconductors and Burstein-Moss effect have been correlated first time to figure out the conductivity type of ZnO. Hall Effect in the Van der Pauw configuration has been applied to reconcile our theoretical estimations which evince our assumption. Band-gap narrowing has been found in all p-type samples, whereas blue Burstein-Moss shift has been recorded in the n-type films. Atomic Force Microscopic (AFM) analysis shows that both p-type and n-type films have almost same granular-like structure with minor change in average grain size (˜ 6 nm to 10 nm) and surface roughness rms value 3 nm for thickness ˜315 nm which points that grain size and surface roughness did not play any significant role in order to modulate the conductivity type of ZnO. X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) have been employed to perform the structural, chemical and elemental analysis. Hexagonal wurtzite structure has been observed in all samples. The introduction of nitrogen reduces the crystallinity of host lattice. 97% transmittance in the visible range with 1.4 × 107 Ω-1cm-1 optical conductivity have been detected. High absorption value in the ultra-violet (UV) region reveals that NZOs thin films can be used to fabricate next-generation high-performance UV detectors.

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.

Advocacy and Alternative Settings as Intervention Strategies for Reducing the Achievement Gap

ERIC Educational Resources Information Center

Thomas, Dominique

2013-01-01

The academic achievement gap between African Americans and their White counterparts has been an issue that has been discussed and dissected for several decades. In 2010, the Schott foundation released a report on Black males in school. It was reported that for the 2007-08 school year, there was only a 47% high school graduation rate for Black…

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…

Decreasing the Gap: Understanding the Role of READ 180 in Helping to Decrease the Achievement Gap for Middle School Students

ERIC Educational Resources Information Center

Neubert, Emily Sarah

2017-01-01

As federal mandates continue to emphasize the use of standardized tests, academic research is needed to determine if reading intervention programs are helping to close the achievement gap between struggling readers and their grade level peers. Although previous research indicated that reading intervention can be an effective tool for increasing…

Understanding the Gender Gap.

ERIC Educational Resources Information Center

Goldin, Claudia

1985-01-01

Despite the great influx of women into the labor market, the gap between men's and women's wages has remained stable at 40 percent since 1950. Analysis of labor data suggests that this has occurred because women's educational attainment compared to men has declined. Recently, however, the wage gap has begun to narrow, and this will probably become…

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…

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…

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

ERIC Educational Resources Information Center

Meece, Darrell; Wingate, Kimberly O'Kelley

2010-01-01

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

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…

The Development of Gender Achievement Gaps in Mathematics and Reading during Elementary and Middle School: Examining Direct Cognitive Assessments and Teacher Ratings

ERIC Educational Resources Information Center

Robinson, Joseph Paul; Lubienski, Sarah Theule

2011-01-01

Using K-8 national longitudinal data, the authors investigate males' and females' achievement in math and reading, including when gender gaps first appear, whether the appearance of gaps depends on the metric used, and where on the achievement distribution gaps are most prevalent. Additionally, teachers' assessments of males and females are…

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…

Resource needs and gap analysis in achieving universal access to HIV/AIDS services: a data envelopment analysis of 45 countries.

PubMed

Zeng, Wu; Shepard, Donald S; Avila-Figueroa, Carlos; Ahn, Haksoon

2016-06-01

-To manage the human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) epidemic, international donors have pledged unprecedented commitments for needed services. The Joint United Nations Programme on HIV/AIDS (UNAIDS) projected that low- and middle-income countries needed $25 billion to meet the 2010 HIV/AIDS goal of universal access to AIDS prevention and care, using the resource needs model (RNM). -Drawing from the results from its sister study, which used a data envelopment analysis (DEA) and a Tobit model to evaluate and adjust the technical efficiency of 61 countries in delivering HIV/AIDS services from 2002 to 2007, this study extended the DEA and developed an approach to estimate resource needs and decompose the performance gap into efficiency gap and resource gap. In the DEA, we considered national HIV/AIDS spending as the input and volume of voluntary counseling and testing (VCT), prevention of mother to child transmission (PMTCT) and antiretroviral treatment (ART) as the outputs. An input-oriented DEA model was constructed to project resource needs in achieving 2010 HIV/AIDS goal for 45 countries using the data in 2006, assuming that all study countries maximized efficiency. -The DEA approach demonstrated the potential to include efficiency of national HIV/AIDS programmes in resource needs estimation, using macro-level data. Under maximal efficiency, the annual projected resource needs for the 45 countries was $6.3 billion, ∼47% of their UNAIDS estimate of $13.5 billion. Given study countries' spending of $3.9 billion, improving efficiency could narrow the gap from $9.6 to $2.4 billion. The results suggest that along with continued financial commitment to HIV/AIDS, improving the efficiency of HIV/AIDS programmes would accelerate the pace to reach 2010 HIV/AIDS goals. The DEA approach provides a supplement to the AIDS RNM to inform policy making. © The Author 2015. Published by Oxford University Press. All rights reserved. For

Schottky diode model for non-parabolic dispersion in narrow-gap semiconductor and few-layer graphene

NASA Astrophysics Data System (ADS)

Ang, Yee Sin; Ang, L. K.; Zubair, M.

Despite the fact that the energy dispersions are highly non-parabolic in many Schottky interfaces made up of 2D material, experimental results are often interpreted using the conventional Schottky diode equation which, contradictorily, assumes a parabolic energy dispersion. In this work, the Schottky diode equation is derived for narrow-gap semiconductor and few-layer graphene where the energy dispersions are highly non-parabolic. Based on Kane's non-parabolic band model, we obtained a more general Kane-Schottky scaling relation of J (T2 + γkBT3) which connects the contrasting J T2 in the conventional Schottky interface and the J T3 scaling in graphene-based Schottky interface via a non-parabolicity parameter, γ. For N-layer graphene of ABC -stacking and of ABA -stacking, the scaling relation follows J T 2 / N + 1 and J T3 respectively. Intriguingly, the Richardson constant extracted from the experimental data using an incorrect scaling can differ with the actual value by more than two orders of magnitude. Our results highlights the importance of using the correct scaling relation in order to accurately extract important physical properties, such as the Richardson constant and the Schottky barrier's height.

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

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…

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…

Narrow-gap physical vapour deposition synthesis of ultrathin SnS1-xSex (0 ≤ x ≤ 1) two-dimensional alloys with unique polarized Raman spectra and high (opto)electronic properties.

PubMed

Gao, Wei; Li, Yongtao; Guo, Jianhua; Ni, Muxun; Liao, Ming; Mo, Haojie; Li, Jingbo

2018-05-10

Here we report ultrathin SnS1-xSex alloyed nanosheets synthesized via a narrow-gap physical vapour deposition approach. The SnS1-xSex alloy presents a uniform quadrangle shape with a lateral size of 5-80 μm and a thickness of several nanometers. Clear orthorhombic symmetries and unique in-plane anisotropic properties of the 2D alloyed nanosheets were found with the help of X-ray diffraction, high resolution transmission electron microscopy and polarized Raman spectroscopy. Moreover, 2D alloyed field-effect transistors were fabricated, exhibiting a unipolar p-type semiconductor behavior. This study also provided a lesson that the thickness of the alloyed channels played the major role in the current on/off ratio, and the high ratio of 2.10 × 102 measured from a large ultrathin SnS1-xSex device was two orders of magnitude larger than that of previously reported SnS, SnSe nanosheet based transistors because of the capacitance shielding effect. Obviously enhanced Raman peaks were also found in the thinner nanosheets. Furthermore, the ultrathin SnS0.5Se0.5 based photodetector showed a highest responsivity of 1.69 A W-1 and a short response time of 40 ms under illumination of a 532 nm laser from 405 to 808 nm. Simultaneously, the corresponding highest external quantum efficiency of 392% and detectivity of 3.96 × 104 Jones were also achieved. Hopefully, the narrow-gap synthesis technique provides us with an improved strategy to obtain large ultrathin 2D nanosheets which may tend to grow into thicker ones for stronger interlayer van der Waals forces, and the enhanced physical and (opto)electrical performances in the obtained ultrathin SnS1-xSex alloyed nanosheets prove their great potential in the future applications for versatile devices.

Origin of band gap bowing in dilute GaAs1-xNx and GaP1-xNx alloys: A real-space view

NASA Astrophysics Data System (ADS)

Virkkala, Ville; Havu, Ville; Tuomisto, Filip; Puska, Martti J.

2013-07-01

The origin of the band gap bowing in dilute nitrogen doped gallium based III-V semiconductors is largely debated. In this paper we show the dilute GaAs1-xNx and GaP1-xNx as representative examples that the nitrogen-induced states close to the conduction band minimum propagate along the zigzag chains on the {110} planes. Thereby states originating from different N atoms interact with each other resulting in broadening of the nitrogen-induced states which narrows the band gap. Our modeling based on ab initio theoretical calculations explains the experimentally observed N concentration dependent band gap narrowing both qualitatively and quantitatively.

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…

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.

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

PubMed

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

2015-01-01

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

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,…

The Effect of High N-DOPED Anatase TiO2 on the Band Gap Narrowing and Redshift by First-Principles

NASA Astrophysics Data System (ADS)

Hou, Qingyu; Jin, Yongjun; Ying, Chun; Zhao, Erjun; Zhang, Yue; Dong, Hongying

2012-10-01

Anatase TiO2 supercells were studied by first-principles, in which one was undoped and another three were high N-doping. Partial densities of states, band structure, population and absorption spectrum were calculated. The calculated results indicated that in the condition of TiO2-xNx (x = 0.0625, 0.125, 0.25), the higher the doping concentration is, the shorter will be the lattice parameters parallel to the direction of c-axis. The strength of covalent bond significantly varied. The formation energy increases at first, and then decreases. The doping models become less stable as N-doping concentration increases. Meanwhile, the narrower the band gap is, the more significant will be the redshift, which is in agreement with the experimental results.

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.

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…

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

ERIC Educational Resources Information Center

Cross, Beverly E.

2007-01-01

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

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

ERIC Educational Resources Information Center

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

2012-01-01

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

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,…

Narrowing the Gender Gap:Empowering Women through Literacy Programmes: Case Studies from the UNESCO Effective Literacy and Numeracy Practices Database (LitBase) http://www.unesco.org/uil/litbase/. 2nd Edition

ERIC Educational Resources Information Center

Hanemann, Ulrike, Ed.

2015-01-01

UIL has published a second edition of a collection of case studies of promising literacy programmes that seek to empower women. "Narrowing the Gender Gap: Empowering Women through Literacy Programmes" (originally published in 2013 as "Literacy Programmes with a Focus on Women to Reduce Gender Disparities") responds to the…

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

PubMed

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

2016-08-01

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

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…

Racial and Gender Gaps in Academic Achievement: An Updated Look at 1993-94 Data. Report Summary.

ERIC Educational Resources Information Center

Dulaney, Chuck; Bethune, Ginger

This second annual report for the Wake County (North Carolina) Public School System examined students' achievement indicators among groups that vary in gender, race, and economic status. The graphic format displays the extent of some of the gaps in academic achievement among the groups examined that existed in the 1993-94 school year, and compares…

FINAL REPORT ON GDE GAP CELL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herman, D.; Summers, W.; Danko, E.

2009-09-28

A project has been undertaken to develop an electrochemical cell and support equipment for evaluation of a gas diffusion electrode-based, narrow-electrolyte-gap anode for SO{sub 2} oxidation in the hydrogen production cycle of the hybrid sulfur (HyS) process. The project supported the HyS development program at the Savannah River National Lab (SRNL). The benefits of using a gas diffusion electrode in conjunction with the narrow anolyte gap are being determined through electrochemical polarization testing under a variety conditions, and by comparison to results produced by SRNL and others using anode technologies that have no anolyte gap. These test results indicate thatmore » the NGA cell has low resistance suitable for use in the HyS electrolyzer, exhibits good efficiency at high current densities compared to the direct feed HyS electrolyzer, and indicates robust performance in extended testing over 65 hours. Seepage episodes were mostly caused by port clogging, which can be mitigated in future designs through minor modifications to the hardware. Significant reductions in sulfur crossover have not yet been demonstrated in the NGA configuration compared to in-house direct feed testing, but corroborative sulfur layer analysis is as yet incomplete. Further testing in a single-pass anolyte configuration is recommended for complete evaluation of steady-state electrochemical efficiency and SO{sub 2} crossover in the narrow gap configuration.« less

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. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Black-White Achievement Gap and Family Wealth

ERIC Educational Resources Information Center

Yeung, W. Jean; Conley, Dalton

2008-01-01

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

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…

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

PubMed

Diprete, Thomas A; Jennings, Jennifer L

2012-01-01

Though many studies have suggested that social and behavioral skills play a central role in gender stratification processes, we know little about the extent to which these skills affect gender gaps in academic achievement. Analyzing data from the Early Child Longitudinal Study-Kindergarten Cohort, we demonstrate that social and behavioral skills have substantively important effects on academic outcomes from kindergarten through fifth grade. Gender differences in the acquisition of these skills, moreover, explain a considerable fraction of the gender gap in academic outcomes during early elementary school. Boys get roughly the same academic return to social and behavioral skills as their female peers, but girls begin school with more advanced social and behavioral skills and their skill advantage grows over time. While part of the effect may reflect an evaluation process that rewards students who better conform to school norms, our results imply that the acquisition of social and behavioral skills enhances learning as well. Our results call for a reconsideration of the family and school-level processes that produce gender gaps in social and behavioral skills and the advantages they confer for academic and later success. Copyright © 2011 Elsevier Inc. All rights reserved.

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…

Attacking the Achievement Gap in a Diverse Urban-Suburban Community: A Curricular Case Study

ERIC Educational Resources Information Center

Alson, Allan

2006-01-01

The persistent and significant achievement gap between black and Latino students and their white and Asian counterparts at Evanston (Illinois) Township High School (ETHS) has existed for as long as anyone can remember. Stories real and apocryphal abound about the institutional barriers that have denied fairness and opportunity for minority…

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…

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

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

ERIC Educational Resources Information Center

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

2008-01-01

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

Photovoltaic measurement of bandgap narrowing in moderately doped silicon

NASA Astrophysics Data System (ADS)

del Alamo, Jesus A.; Swanson, Richard M.; Lietoila, Arto

1983-05-01

Solar cells have been fabricated on n-type and p-type moderately doped Si. The shrinkage of the Si bandgap has been obtained by measuring the internal quantum efficiency in the near infrared spectrum ( hv = 1.00-1.25 eV) around the fundamental absorption edge. The results agree with previous optical measurements of bandgap narrowing in Si. It is postulated that this optically-determined bandgap narrowing is the rigid shrinkage of the forbidden gap due to many-body effects. The "device bandgap narrowing" obtained by measuring the pn product in bipolar devices leads to discrepant values because (i) the density of states in the conduction and valence band is modified due to the potential fluctuations originated in the variations in local impurity density, and (ii) the influence of Fermi-Dirac statistics.

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…

Divergent Streams: Race-Gender Achievement Gaps at Selective Colleges and Universities.

PubMed

Massey, Douglas S; Probasco, Lierin

2010-03-01

In this paper, we extend previous research on racial performance gaps at 28 selective US colleges and universities by examining differences in grade achievement and graduate rates across race-gender categories. Using data from the National Longitudinal Survey of Freshmen, we show that black males, black females, and Hispanic males attain significantly lower grades than other race-gender groups, and that black males are 35% less likely to graduate on-time than other race-gender groups. Analyses consider an array of personal and institutional indicators of academic performance. Grades and graduation rates are improved by academic preparation (particularly high school GPA), scholarly effort, and, for graduation rates, membership in career-oriented or majority-white campus groups. Grade performance and graduation rates are undermined by a hostile racial climate on campus, family stress, and stereotype threat, all of which disproportionately affect minority students. We conclude with recommendations to college administrators for ways of selecting and supporting minority students to reduce differentials in academic achievement across race-gender groups.

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…

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…

Bridging the Civil Military Gap Capitalizing on Crisis

DTIC Science & Technology

2002-01-01

solutions. Researchers identifying the sources of the gap discussed above, have also suggested some methods for reducing the gap . While some are policy...Strategy Research Project DATE: 09 April 2002 PAGES: 42 CLASSIFICATION: Unclassified Researchers have identified a "civil-military gap ," an observable...would indicate a desire by the civilian populous to draw closer to the military, creating an opportunity to close or at least narrow this gap . The media

Disproportionality Fills in the Gaps: Connections between Achievement, Discipline and Special Education in the School-to-Prison Pipeline

ERIC Educational Resources Information Center

Annamma, Subini; Morrison, Deb; Jackson, Darrell

2014-01-01

The focus on the achievement gap has overshadowed ways in which school systems constrain student achievement through trends of racial disproportionality in areas such as school discipline, special education assignment, and juvenile justice. Using Critical Race Theory, we reframe these racial disparities as issues of institutionalized racism.…

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…

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…

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

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…

Closing the N-use efficiency gap to achieve food and environmental security.

PubMed

Cui, Zhenling; Wang, Guiliang; Yue, Shanchao; Wu, Liang; Zhang, Weifeng; Zhang, Fusuo; Chen, Xinping

2014-05-20

To achieve food and environmental security, closing the gap between actual and attainable N-use efficiency should be as important as closing yield gaps. Using a meta-analysis of 205 published studies from 317 study sites, including 1332 observations from rice, wheat, and maize system in China, reactive N (Nr) losses, and total N2O emissions from N fertilization both increased exponentially with increasing N application rate. On the basis of the N loss response curves from the literature meta-analysis, the direct N2O emission, NH3 volatilization, N leaching, and N runoff, and total N2O emission (direct + indirect) were calculated using information from the survey of farmers. The PFP-N (kilogram of harvested product per kilogram of N applied (kg (kg of N)(-1))) for 6259 farmers were relative low with only 37, 23, and 32 kg (kg of N)(-1) for rice, wheat, and maize systems, respectively. In comparison, the PFP-N for highest yield and PFP-N group (refers to fields where the PFP-N was within the 80-100th percentile among those fields that achieved yields within the 80-100th percentile) averaged 62, 42, and 53 kg (kg of N)(-1) for rice, wheat, and maize systems, respectively. The corresponding grain yield would increase by 1.6-2.3 Mg ha(-1), while the N application rate would be reduced by 56-100 kg of N ha(-1) from average farmer field to highest yield and PFP-N group. In return, the Nr loss intensity (4-11 kg of N (Mg of grain)(-1)) and total N2O emission intensity (0.15-0.29 kg of N (Mg of grain)(-1)) would both be reduced significantly as compared to current agricultural practices. In many circumstances, closing the PFP-N gap in intensive cropping systems is compatible with increased crop productivity and reductions in both Nr losses and total N2O emissions.

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…

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

PubMed Central

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

2013-01-01

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

Values Affirmation Intervention Reduces Achievement Gap between Underrepresented Minority and White Students in Introductory Biology Classes

ERIC Educational Resources Information Center

Jordt, Hannah; Eddy, Sarah L.; Brazil, Riley; Lau, Ignatius; Mann, Chelsea; Brownell, Sara E.; King, Katherine; Freeman, Scott

2017-01-01

Achievement gaps between underrepresented minority (URM) students and their white peers in college science, technology, engineering, and mathematics classrooms are persistent across many white-majority institutions of higher education. Attempts to reduce this phenomenon of underperformance through increasing classroom structure via active learning…

Understanding the Gender Gap in Mathematics Achievement: The Role of Self-Efficacy and Stereotype Threat

ERIC Educational Resources Information Center

Schwery, Denise; Hulac, David; Schweinle, Amy

2016-01-01

This literature review provides school psychologists with an understanding of the important issues related to the gender gap in mathematics achievement. The extant literature suggests that girls tend to receive lower scores than boys on standardized math tests, but in general these differences tend to be small. However, girls have better classroom…

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…

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,…

BC8 Silicon (Si-III) is a Narrow-Gap Semiconductor

NASA Astrophysics Data System (ADS)

Zhang, Haidong; Liu, Hanyu; Wei, Kaya; Kurakevych, Oleksandr O.; Le Godec, Yann; Liu, Zhenxian; Martin, Joshua; Guerrette, Michael; Nolas, George S.; Strobel, Timothy A.

2017-04-01

Large-volume, phase-pure synthesis of BC8 silicon (I a 3 ¯ , c I 16 ) has enabled bulk measurements of optical, electronic, and thermal properties. Unlike previous reports that conclude BC8-Si is semimetallic, we demonstrate that this phase is a direct band gap semiconductor with a very small energy gap and moderate carrier concentration and mobility at room temperature, based on far- and midinfrared optical spectroscopy, temperature-dependent electrical conductivity, Seebeck and heat capacity measurements. Samples exhibit a plasma wavelength near 11 μ m , indicating potential for infrared plasmonic applications. Thermal conductivity is reduced by 1-2 orders of magnitude depending on temperature as compared with the diamond cubic (DC-Si) phase. The electronic structure and dielectric properties can be reproduced by first-principles calculations with hybrid functionals after adjusting the level of exact Hartree-Fock (HF) exchange mixing. These results clarify existing limited and controversial experimental data sets and ab initio calculations.

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)

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.

Omnidirectional narrow optical filters for circularly polarized light in a nanocomposite structurally chiral medium.

PubMed

Avendaño, Carlos G; Palomares, Laura O

2018-04-20

We consider the propagation of electromagnetic waves throughout a nanocomposite structurally chiral medium consisting of metallic nanoballs randomly dispersed in a structurally chiral material whose dielectric properties can be represented by a resonant effective uniaxial tensor. It is found that an omnidirectional narrow pass band and two omnidirectional narrow band gaps are created in the blue optical spectrum for right and left circularly polarized light, as well as narrow reflection bands for right circularly polarized light that can be controlled by varying the light incidence angle and the filling fraction of metallic inclusions.

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…

Gender and Minority Achievement Gaps in Science in Eighth Grade: Item Analyses of Nationally Representative Data. Research Report. ETS RR-17-36

ERIC Educational Resources Information Center

Qian, Xiaoyu; Nandakumar, Ratna; Glutting, Joseoph; Ford, Danielle; Fifield, Steve

2017-01-01

In this study, we investigated gender and minority achievement gaps on 8th-grade science items employing a multilevel item response methodology. Both gaps were wider on physics and earth science items than on biology and chemistry items. Larger gender gaps were found on items with specific topics favoring male students than other items, for…

Investigation on microstructure and properties of narrow-gap laser welding on reduced activation ferritic/martensitic steel CLF-1 with a thickness of 35 mm

NASA Astrophysics Data System (ADS)

Wu, Shikai; Zhang, Jianchao; Yang, Jiaoxi; Lu, Junxia; Liao, Hongbin; Wang, Xiaoyu

2018-05-01

Reduced activation ferritic martensitic (RAFM) steel is chosen as a structural material for test blanket modules (TBMs) to be constructed in International Thermonuclear Experimental Reactor (ITER) and China Fusion Engineering Test Reactor (CFETR). Chinese specific RAFM steel named with CLF-1 has been developed for CFETR. In this paper, a narrow-gap groove laser multi-pass welding of CLF-1 steel with thickness of 35 mm is conduced by YLS-15000 fiber laser. Further, the microstructures of different regions in the weld joint were characterized, and tensile impact and micro-hardness tests were carried out for evaluating the mecharical properties. The results show that the butt weld joint of CLF-1 steel with a thickness of 35 mm was well-formed using the optimal narrow-gap laser filler wire welding and no obvious defects was found such as incomplete fusion cracks and pores. The microstructures of backing layer is dominated by lath martensites and the Heat-Affected Zone (HAZ) was mainly filled with two-phase hybrid structures of secondary-tempering sorbites and martensites. The filler layer is similar to the backing layer in microstructures. In tensile tests, the tensile samples from different parts of the joint all fractured at base metal (BM). The micro-hardness of weld metal (WM) was found to be higher than that of BM and the Heat-Affected Zone (HAZ) exhibited no obvious softening. After post weld heat treatment (PWHT), it can be observed that the fusion zone of the autogenous welding bead and the upper filling beads mainly consist of lath martensites which caused the lower impact absorbing energy. The HAZ mainly included two-phase hybrid structures of secondary-tempering sorbites and martensites and exhibited favorable impact toughness.

College for All: Gaps between Desirable and Actual P-12 Math Achievement Trajectories for College Readiness

ERIC Educational Resources Information Center

Lee, Jaekyung

2012-01-01

This study addresses missing links in "college for all" debates by investigating gaps between actual and desirable math achievement trajectories for students' college readiness. Linking multiple national data sets across P-16 education levels, the study estimates college readiness benchmarks separately for two-year and four-year college…

For blacks in America, the gap in neighborhood poverty has declined faster than segregation.

PubMed

Firebaugh, Glenn; Acciai, Francesco

2016-11-22

Black residential segregation has been declining in the United States. That accomplishment rings hollow, however, if blacks continue to live in much poorer neighborhoods than other Americans. This study uses census data for all US metropolitan areas in 1980 and 2010 to compare decline in the neighborhood poverty gap between blacks and other Americans with decline in the residential segregation of blacks. We find that both declines resulted primarily from narrowing differences between blacks and whites as opposed to narrowing differences between blacks and Hispanics or blacks and Asians. Because black-white differences in neighborhood poverty declined much faster than black-white segregation, the neighborhood poverty disadvantage of blacks declined faster than black segregation-a noteworthy finding because the narrowing of the racial gap in neighborhood poverty for blacks has gone largely unnoticed. Further analysis reveals that the narrowing of the gap was produced by change in both the medians and shapes of the distribution of poverty across the neighborhoods where blacks, whites, Hispanics, and Asians reside.

Religiosity, Religious Schools, and Their Relationship with the Achievement Gap: A Research Synthesis and Meta-Analysis

ERIC Educational Resources Information Center

Jeynes, William H.

2010-01-01

A research synthesis was conducted including three meta analyses, a review of the relevant literature, and supplemental analyses examining the relationship between personal faith and the reduction of the achievement gap. Personal faith included belief and adherence to any religion. The results of the three meta-analyses indicated that: (a)…

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.

Ethnicity, Gender, Social Class and Achievement Gaps at Age 16: Intersectionality and "Getting It" for the White Working Class

ERIC Educational Resources Information Center

Strand, Steve

2014-01-01

Perhaps the most prevailing inequalities in educational achievement in England are those associated with socio-economic status (SES), ethnicity and gender. However, little research has sought to compare the relative size of these gaps or to explore interactions between these factors. This paper analyses the educational achievement at age 11, 14…

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…

A Quasi-Classical Model of the Hubbard Gap in Lightly Compensated Semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poklonski, N. A.; Vyrko, S. A.; Kovalev, A. I.

2016-03-15

A quasi-classical method for calculating the narrowing of the Hubbard gap between the A{sup 0} and A{sup +} acceptor bands in a hole semiconductor or the D{sup 0} and D{sup –} donor bands in an electron semiconductor is suggested. This narrowing gives rise to the phenomenon of a semiconductor transition from the insulator to metal state with an increase in doping level. The major (doping) impurity can be in one of three charge states (–1, 0, or +1), while the compensating impurity can be in states (+1) or (–1). The impurity distribution over the crystal is assumed to be randommore » and the width of Hubbard bands (levels), to be much smaller than the gap between them. It is shown that narrowing of the Hubbard gap is due to the formation of electrically neutral acceptor (donor) states of the quasicontinuous band of allowed energies for holes (electrons) from excited states. This quasicontinuous band merges with the top of the valence band (v band) for acceptors or with the bottom of the conduction band (c band) for donors. In other words, the top of the v band for a p-type semiconductor or the bottom of the c band for an n-type semiconductor is shifted into the band gap. The value of this shift is determined by the maximum radius of the Bohr orbit of the excited state of an electrically neutral major impurity atom, which is no larger than half the average distance between nearest impurity atoms. As a result of the increasing dopant concentration, the both Hubbard energy levels become shallower and the gap between them narrows. Analytical formulas are derived to describe the thermally activated hopping transition of holes (electrons) between Hubbard bands. The calculated gap narrowing with increasing doping level, which manifests itself in a reduction in the activation energy ε{sub 2} is consistent with available experimental data for lightly compensated p-Si crystals doped with boron and n-Ge crystals doped with antimony.« less

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…

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

ERIC Educational Resources Information Center

Shafiq, M. Najeeb

2011-01-01

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

Narrowing the Insurance Protection Gap: The important role of Natural Hazards Research

NASA Astrophysics Data System (ADS)

Manghnani, V.

2016-12-01

risks is a key determinant to supporting a thriving insurance marketplace. This will ensure that the industry can confidently and creatively offer insurance to perils and hazards in both developed and developing economies and continue to narrow the protection gap.

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…

Reducing the Achievement Gap.

ERIC Educational Resources Information Center

McCombs, Barbara L.

2000-01-01

Reviews the College Board's report, "Reaching the Top," which addresses educational underrepresentation of high-achieving minority students, examining how social sciences, psychology, and education research contribute to an understanding of the feasibility of the report's recommendations and noting implications of these recommendations…

Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms

PubMed Central

Brownell, Sara E.; Wenderoth, Mary Pat

2014-01-01

Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel. PMID:25185231

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

Development of the literacy achievement gap: a longitudinal study of kindergarten through third grade.

PubMed

Foster, Wayne A; Miller, Merideth

2007-07-01

The major goal of this study was to specify the developmental trajectories for phonics and early text comprehension skills of children from kindergarten through third grade. Data from the Early Childhood Longitudinal Study (N = 12,261) were used in this study. The participants were divided into 3 school readiness groups based on an assessment of literacy skill development at the time of entrance into kindergarten. The different groups were tracked on phonics and text comprehension development through the third grade. Students in the average and high literacy readiness groups achieved high scores in decoding (phonics) by the end of the first grade. Students in the low readiness group did not match these scores until the third grade. Although the phonics gap was essentially closed in the third grade, a second, very significant text comprehension gap was exposed. The 3 readiness groups were analyzed to assess the relative contributions of parent education, income, and kindergarten literacy score to third-grade literacy achievement. The results of this study stress the need for speech-language pathologists to assess emergent literacy skills in their speech and language clients and to include appropriate literacy goals in the treatment regimen as a means for reducing the potential need for identification as learning disabled in reading in the later years of elementary school.

Science Achievement Gaps by Gender and Race/Ethnicity in Elementary and Middle School: Trends and Predictors

ERIC Educational Resources Information Center

Quinn, David M.; Cooc, North

2015-01-01

Research on science achievement disparities by gender and race/ethnicity often neglects the beginning of the pipeline in the early grades. We address this limitation using nationally representative data following students from Grades 3 to 8. We find that the Black-White science test score gap (-1.07 SD in Grade 3) remains stable over these years,…

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.

Why Race and Culture Matter in Schools: Closing the Achievement Gap in America's Classrooms. Multicultural Education Series

ERIC Educational Resources Information Center

Howard, Tyrone C.

2010-01-01

While race and culture remain important variables in how young people experience schools, they are often misunderstood by educators and school personnel. Building on the work of three studies that investigated schools successful in closing the achievement gap, Tyrone Howard shows how adopting greater awareness and comprehensive understanding of…

For blacks in America, the gap in neighborhood poverty has declined faster than segregation

PubMed Central

Acciai, Francesco

2016-01-01

Black residential segregation has been declining in the United States. That accomplishment rings hollow, however, if blacks continue to live in much poorer neighborhoods than other Americans. This study uses census data for all US metropolitan areas in 1980 and 2010 to compare decline in the neighborhood poverty gap between blacks and other Americans with decline in the residential segregation of blacks. We find that both declines resulted primarily from narrowing differences between blacks and whites as opposed to narrowing differences between blacks and Hispanics or blacks and Asians. Because black–white differences in neighborhood poverty declined much faster than black–white segregation, the neighborhood poverty disadvantage of blacks declined faster than black segregation—a noteworthy finding because the narrowing of the racial gap in neighborhood poverty for blacks has gone largely unnoticed. Further analysis reveals that the narrowing of the gap was produced by change in both the medians and shapes of the distribution of poverty across the neighborhoods where blacks, whites, Hispanics, and Asians reside. PMID:27821759

Recursive processes in self-affirmation: intervening to close the minority achievement gap.

PubMed

Cohen, Geoffrey L; Garcia, Julio; Purdie-Vaughns, Valerie; Apfel, Nancy; Brzustoski, Patricia

2009-04-17

A 2-year follow-up of a randomized field experiment previously reported in Science is presented. A subtle intervention to lessen minority students' psychological threat related to being negatively stereotyped in school was tested in an experiment conducted three times with three independent cohorts (N = 133, 149, and 134). The intervention, a series of brief but structured writing assignments focusing students on a self-affirming value, reduced the racial achievement gap. Over 2 years, the grade point average (GPA) of African Americans was, on average, raised by 0.24 grade points. Low-achieving African Americans were particularly benefited. Their GPA improved, on average, 0.41 points, and their rate of remediation or grade repetition was less (5% versus 18%). Additionally, treated students' self-perceptions showed long-term benefits. Findings suggest that because initial psychological states and performance determine later outcomes by providing a baseline and initial trajectory for a recursive process, apparently small but early alterations in trajectory can have long-term effects. Implications for psychological theory and educational practice are discussed.

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…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Wenliang; Yang, Pingxiong, E-mail: pxyang@ee.ecnu.edu.cn; Chu, Junhao

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 ismore » 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.« less

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…

New Mexico's Academic Achievement Gaps: A Synthesis of Status, Causes, and Solutions. A White Paper

ERIC Educational Resources Information Center

Martinez, Joseph P.

2017-01-01

The Center for Positive Practices (CPP) conducted an analysis and synthesis of K-12 educational achievement gaps in New Mexico. The white paper was requested by the New Mexico based Coalition for the Majority, which includes various institutions, organizations and individuals supporting the New Mexico English Learner Teacher Preparation Act. The…

Leveling the Playing Field: Using a One-to-One Laptop Initiative to Close the Achievement Gap

ERIC Educational Resources Information Center

Smith, Luke Andrew

2012-01-01

The purpose of this study was to examine how the one-to-one laptop initiative affected student achievement gaps for students at a single high school in Mooresville, NC. The variable in this study was the preexisting End of Course exams for Algebra I and English I for the two school years prior to the one-to-one laptop implementation year…

Aerodynamic and acoustic effects of ventricular gap.

PubMed

Alipour, Fariborz; Karnell, Michael

2014-03-01

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. 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 were recorded during phonation when the ventricular gap was narrow, neutral, and large. Glottal resistance was estimated by measures of subglottal pressure and glottal flow. 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. 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, physiological, 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. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

An enhanced narrow-band imaging method for the microvessel detection

NASA Astrophysics Data System (ADS)

Yu, Feng; Song, Enmin; Liu, Hong; Wan, Youming; Zhu, Jun; Hung, Chih-Cheng

2018-02-01

A medical endoscope system combined with the narrow-band imaging (NBI), has been shown to be a superior diagnostic tool for early cancer detection. The NBI can reveal the morphologic changes of microvessels in the superficial cancer. In order to improve the conspicuousness of microvessel texture, we propose an enhanced NBI method to improve the conspicuousness of endoscopic images. To obtain the more conspicuous narrow-band images, we use the edge operator to extract the edge information of the narrow-band blue and green images, and give a weight to the extracted edges. Then, the weighted edges are fused with the narrow-band blue and green images. Finally, the displayed endoscopic images are reconstructed with the enhanced narrow-band images. In addition, we evaluate the performance of enhanced narrow-band images with different edge operators. Experimental results indicate that the Sobel and Canny operators achieve the best performance of all. Compared with traditional NBI method of Olympus company, our proposed method has more conspicuous texture of microvessel.

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. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

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…

Yb5Ga2Sb6: a mixed valent and narrow-band gap material in the RE5M2X6 family.

PubMed

Subbarao, Udumula; Sarkar, Sumanta; Gudelli, Vijay Kumar; Kanchana, V; Vaitheeswaran, G; Peter, Sebastian C

2013-12-02

A new compound Yb5Ga2Sb6 was synthesized by the metal flux technique as well as high frequency induction heating. Yb5Ga2Sb6 crystallizes in the orthorhombic space group Pbam (no. 55), in the Ba5Al2Bi6 structure type, with a unit cell of a = 7.2769(2) Å, b = 22.9102(5) Å, c = 4.3984(14) Å, and Z = 2. Yb5Ga2Sb6 has an anisotropic structure with infinite anionic double chains (Ga2Sb6)(10-) cross-linked by Yb(2+) and Yb(3+) ions. Each single chain is made of corner-sharing GaSb4 tetrahedra. Two such chains are bridged by Sb2 groups to form double chains of 1/∞ [Ga2Sb6(10-)]. The compound satisfies the classical Zintl-Klemm concept and is a narrow band gap semiconductor with an energy gap of around 0.36 eV calculated from the electrical resistivity data corroborating with the experimental absorption studies in the IR region (0.3 eV). Magnetic measurements suggest Yb atoms in Yb5Ga2Sb6 exist in the mixed valent state. Temperature dependent magnetic susceptibility data follows the Curie-Weiss behavior above 100 K and no magnetic ordering was observed down to 2 K. Experiments are accompanied by all electron full-potential linear augmented plane wave (FP-LAPW) calculations based on density functional theory to calculate the electronic structure and density of states. The calculated band structure shows a weak overlap of valence band and conduction band resulting in a pseudo gap in the density of states revealing semimetallic character.

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…

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

ERIC Educational Resources Information Center

National Center for Education Statistics, 2011

2011-01-01

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

Dynamic film thickness between bubbles and wall in a narrow channel

NASA Astrophysics Data System (ADS)

Ito, Daisuke; Damsohn, Manuel; Prasser, Horst-Michael; Aritomi, Masanori

2011-09-01

The present paper describes a novel technique to characterize the behavior of the liquid film between gas bubbles and the wall in a narrow channel. The method is based on the electrical conductance. Two liquid film sensors are installed on both opposite walls in a narrow rectangular channel. The liquid film thickness underneath the gas bubbles is recorded by the first sensor, while the void fraction information is obtained by measuring the conductance between the pair of opposite sensors. Both measurements are taken on a large two-dimensional domain and with a high speed. This makes it possible to obtain the two-dimensional distribution of the dynamic liquid film between the bubbles and the wall. In this study, this method was applied to an air-water flow ranging from bubbly to churn regimes in the narrow channel with a gap width of 1.5 mm.

The Role of Collective Efficacy in Closing Student Achievement Gaps: A Mixed Methods Study of School Leadership for Excellence and Equity

ERIC Educational Resources Information Center

Goddard, Roger D.; Skrla, Linda; Salloum, Serena J.

2017-01-01

Previous research demonstrates that collective efficacy positively predicts students' academic achievement (e.g., Bandura, 1993; Goddard et al., 2000). However, unaddressed by the current literature is whether collective efficacy also works to reduce inequity by closing achievement gaps. To learn about the operation of collective efficacy, we…

The New State Achievement Gap: How Federal Waivers Could Make It Worse--or Better. Education Sector Reports

ERIC Educational Resources Information Center

Chubb, John; Clark, Constance

2013-01-01

With the adoption of the No Child Left Behind Act (NCLB) in 2002, the federal government signaled its intention to close achievement gaps in K-12 education, particularly for minority students. While there has been surprising progress in educating disadvantaged students since the law was passed, according to a new report released today by Education…

Gap analysis: synergies and opportunities for effective nursing leadership.

PubMed

Davis-Ajami, Mary Lynn; Costa, Linda; Kulik, Susan

2014-01-01

Gap analysis encompasses a comprehensive process to identify, understand, address, and bridge gaps in service delivery and nursing practice. onducting gap analysis provides structure to information gathering and the process of finding sustainable solutions to important deficiencies. Nursing leaders need to recognize, measure, monitor, and execute on feasible actionable solutions to help organizations make adjustments to address gaps between what is desired and the actual real-world conditions contributing to the quality chasm in health care. Gap analysis represents a functional and comprehensive tool to address organizational deficiencies. Using gap analysis proactively helps organizations map out and sustain corrective efforts to close the quality chasm. Gaining facility in gap analysis should help the nursing profession's contribution to narrowing the quality chasm.

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)

Trajectories of Achievement within Race/Ethnicity: "Catching Up" in Achievement across Time

ERIC Educational Resources Information Center

Davis-Kean, Pamela E.; Jager, Justin

2014-01-01

The achievement gap has long been the focus of educational research, policy, and intervention. The authors took a new approach to examining the achievement gap by examining achievement trajectories within each racial group. To identify these trajectories they used the Early Childhood Longitudinal Study-Kindergarten Cohort, which is a nationally…

The Black-White "Achievement Gap" as a Perennial Challenge of Urban Science Education: A Sociocultural and Historical Overview with Implications for Research and Practice.

ERIC Educational Resources Information Center

Norman, Obed; Ault, Charles R., Jr.; Bentz, Bonnie; Meskimen, Lloyd

2001-01-01

Explores how sociocultural factors involved in the manifestation and eventual disappearance of the gap for these groups may shed light on how to address the achievement gap for African American students in urban science education. (Contains 47 references.) (DDR)

No More Profiling in the Classroom: A Midsize Urban School District's Efforts to Close the Achievement Gap

ERIC Educational Resources Information Center

Smith-Evans, Leticia Victoria

2010-01-01

For approximately a third of this decade, a mid-size urban school district took a bold step in its continuing efforts to battle what has been a persistent problem plaguing this Nation's education system for decades or possibly for as long as it has existed--the achievement gap between students of color and their White peers. The district has…

The characteristic of gap FBG and its application

NASA Astrophysics Data System (ADS)

Yang, Yuanhong; Hu, Jun; Liu, Xuejing; Jin, Wei

2015-07-01

A gap fiber Bragg grating (g-FBG) is fabricated by cutting a uniform FBG in the middle to introduce a small air gap between the two sections. Numerical and experimental investigations show that the g-FBG has the characteristics of both a phase shifted FBG and a Fizeau interferometer. The influence of the air-gap shift longitudinally or transversely with respect to the fiber central axis and temperature to g-FBG's spectrums are investigated with numerical simulation and experiments, and the mathematic models are made. Based on g-FBG's different sensitivity to gap width and temperature, a micro-gap and temperature simultaneous measurement sensor was demonstrated. And a g-FBG based tunable fiber ring laser with a narrow line-width is demonstrated.

Aggression and violence and the achievement gap among urban minority youth.

PubMed

Basch, Charles E

2011-10-01

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. Literature review. Recent national data indicate that among students aged 12-18, approximately 628,200 violent crimes and 868,100 thefts occurred. Physical fighting was more commonly reported by Blacks and Hispanics (44.7% and 40.4%, respectively) than Whites (31.7%). In-school threats and injuries were nearly twice as prevalent in cities as in suburbs and towns or rural areas (10% vs 6% and 5%, respectively). Associations between exposure to and exhibition of aggression and violence and unfavorable educational outcomes are well documented. Causal pathways through which aggression and violence impede learning include cognition, school connectedness, and absenteeism. Disruptive classroom behavior is a well-recognized and significant impediment to teaching and learning. Compelling research has shown that various school-based programs can significantly reduce the nature and extent of aggressive and violent behaviors. Violence and aggressive behavior are highly and disproportionately prevalent among school-aged urban minority youth, have a negative impact on academic achievement by adversely affecting cognition, school connectedness, and absenteeism, and effective practices are available for schools to address this problem. Once the domain of criminal justice, aggression and violence are now recognized as an appropriate and important focus of the education and public health systems. Implementing evidence-based school policies and programs to reduce aggression and violence must be a high priority to help close the achievement gap. © 2011, American School Health Association.

Visible-light absorption and large band-gap bowing of GaN 1-xSb x from first principles

DOE PAGES

Sheetz, R. Michael; Richter, Ernst; Andriotis, Antonis N.; ...

2011-08-01

Applicability of the Ga(Sb x)N 1-x alloys for practical realization of photoelectrochemical water splitting is investigated using first-principles density functional theory incorporating the local density approximation and generalized gradient approximation plus the Hubbard U parameter formalism. Our calculations reveal that a relatively small concentration of Sb impurities is sufficient to achieve a significant narrowing of the band gap, enabling absorption of visible light. Theoretical results predict that Ga(Sb x)N 1-x alloys with 2-eV band gaps straddle the potential window at moderate to low pH values, thus indicating that dilute Ga(Sb x)N 1-x alloys could be potential candidates for splitting watermore » under visible light irradiation.« less

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.

Healthier students are better learners: a missing link in school reforms to close the achievement gap.

PubMed

Basch, Charles E

2011-10-01

This article provides an introduction to the October 2011 special issue of the Journal of School Health on "Healthier Students Are Better Learners." Literature was reviewed and synthesized to identify health problems affecting school-aged youth that are highly prevalent, disproportionately affect urban minority youth, directly and indirectly causally affect academic achievement, and can be feasibly and effectively addressed through school health programs and services. Based on these criteria, 7 educationally relevant health disparities were selected as strategic priorities to help close the achievement gap: (1) vision, (2) asthma, (3) teen pregnancy, (4) aggression and violence, (5) physical activity, (6) breakfast, and (7) inattention and hyperactivity. Research clearly shows that these health problems influence students' motivation and ability to learn. Disparities among urban minority youth are outlined, along with the causal pathways through which each adversely affects academic achievement, including sensory perceptions, cognition, school connectedness, absenteeism, and dropping out. Evidence-based approaches that schools can implement to address these problems are presented. These health problems and the causal pathways they influence have interactive and a synergistic effect, which is why they must be addressed collectively using a coordinated approach. No matter how well teachers are prepared to teach, no matter what accountability measures are put in place, no matter what governing structures are established for schools, educational progress will be profoundly limited if students are not motivated and able to learn. Particular health problems play a major role in limiting the motivation and ability to learn of urban minority youth. This is why reducing these disparities through a coordinated approach warrants validation as a cohesive school improvement initiative to close the achievement gap. Local, state, and national policies for implementing this

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…

A Low-Energy-Gap Thienochrysenocarbazole Dye for Highly Efficient Mesoscopic Titania Solar Cells: Understanding the Excited State and Charge Carrier Dynamics.

PubMed

Wang, Junting; Xie, Xinrui; Weng, Guorong; Yuan, Yi; Zhang, Jing; Wang, Peng

2018-05-09

Maintaining both a high external quantum efficiency and a large open-circuit photovoltage of dye-sensitized solar cells (DSSCs) is a crucial challenge in the process of developing narrow-energy-gap dyes for the capture of infrared solar photons. Herein, we report two donor-acceptor organic dyes, C294 and C295, with a polycyclic heteroaromatic unit, 6,11-dihydrothieno[3',2':8,9]chryseno[10,11,12,1-bcdefg]carbazole (TCC), as the central module of the electron donor, and ethylbenzothiadiazole-benzioc acid as the electron acceptor. The interfacial charge recombination was successfully mitigated by introducing an additional branched aliphatic chain in C295. Furthermore, the O⋅⋅⋅S nonbonding interaction between the oxygen atom of the alkoxy group and the sulfur atom of the thiophene in C295 controlled the conformation of C295, resulting in a narrow energy-gap. Time-resolved spectroscopic measurements on C294 and the model dye C272 indicated that the elevation of the HOMO energy level decreased the kinetics and yield of hole injection owing to a reduction in the driving force and that the shortened excited-state lifetime caused by the narrowing of the energy gap was unfavorable for electron injection. By fine tuning the composition of the electrolyte, C294 and C295 eventually achieved high power conversion efficiencies of 11.5 % and 12.4 %, respectively, under full sunlight of air mass 1.5 global conditions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Healthier students are better learners: high-quality, strategically planned, and effectively coordinated school health programs must be a fundamental mission of schools to help close the achievement gap.

PubMed

Basch, Charles E

2011-10-01

To discuss implications for educational policy and practice relevant to closing the achievement gap based on the literature review and synthesis presented in 7 articles of the October 2011 special issue of the Journal of School Health. Implications for closing the achievement gap are drawn from analyses of current literature. During the past several decades, school reform efforts to close the achievement gap have focused on various strategies, yielding very limited progress. Educationally relevant health disparities influence students' motivation and ability to learn, but reducing these disparities has been largely overlooked as an element of an overall strategy for closing the achievement gap. If these health problems are not addressed, the educational benefits of other school reform efforts will be jeopardized. Healthier students are better learners. School health programs and services that are evidence based, strategically planned to influence academic achievement, and effectively coordinated warrant validation as a cohesive school improvement initiative for closing the achievement gap. National, state, and local responsibilities for supporting school health are outlined, including shared strategies; leadership from the U.S. Department of Education; policy development; guidance, technical assistance, and professional development; accountability and data and software systems; and a research agenda. To date, the U.S. Department of Education has not provided leadership for integrating evidence-based, strategically planned, and effectively coordinated school health programs and services into the fundamental mission of schools. Now is an opportune time for change. © 2011, American School Health Association.

Is sprawl associated with a widening urban-suburban mortality gap?

PubMed

Fan, Yingling; Song, Yan

2009-09-01

This paper examines whether sprawl, featured by low development density, segregated land uses, lack of significant centers, and poor street connectivity, contributes to a widening mortality gap between urban and suburban residents. We employ two mortality datasets, including a national cross-sectional dataset examining the impact of metropolitan-level sprawl on urban-suburban mortality gaps and a longitudinal dataset from Portland examining changes in urban-suburban mortality gaps over time. The national and Portland studies provide the only evidence to date that (1) across metropolitan areas, the size of urban-suburban mortality gaps varies by the extent of sprawl: in sprawling metropolitan areas, urban residents have significant excess mortality risks than suburban residents, while in compact metropolitan areas, urbanicity-related excess mortality becomes insignificant; (2) the Portland metropolitan area not only experienced net decreases in mortality rates but also a narrowing urban-suburban mortality gap since its adoption of smart growth regime in the past decade; and (3) the existence of excess mortality among urban residents in US sprawling metropolitan areas, as well as the net mortality decreases and narrowing urban-suburban mortality gap in the Portland metropolitan area, is not attributable to sociodemographic variations. These findings suggest that health threats imposed by sprawl affect urban residents disproportionately compared to suburban residents and that efforts curbing sprawl may mitigate urban-suburban health disparities.

A Test of Leading Explanations for the College Racial-Ethnic Achievement Gap: Evidence from a Longitudinal Case Study

ERIC Educational Resources Information Center

Martin, Nathan D.; Spenner, Kenneth I; Mustillo, Sarah A.

2017-01-01

In this study, we examined racial/ethnic differences in grade point average (GPA) among students at a highly selective, private university who were surveyed before matriculation and during the first, second and fourth college years, and assessed prominent explanations for the Black-White and Latino-White college achievement gap. We found that…

Whites Aren't Bad, Asian Americans Are Just Better: Asymmetrical Attributions for the White-Asian American Achievement Gap

ERIC Educational Resources Information Center

Sperling, Rick; Zwahr-Castro, Jennifer; Cruz, Felicia; Montalvo, Jason

2017-01-01

Previous research has shown that people often engage in cultural-deficit thinking when reasoning about racial/ethnic achievement gaps. However, it is unclear whether culture-blaming explanations are best thought of as group-level internal attributions, expressions of prejudice against a lower status group, or self-serving bias. In this study,…

The theory-practice gap of black carbon mitigation technologies in rural China

NASA Astrophysics Data System (ADS)

Zhang, Weishi; Li, Aitong; Xu, Yuan; Liu, Junfeng

2018-02-01

Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation - the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground - this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies - lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies' performance, are discussed together with policy implications to narrow those gaps.

Fullerene-Free Organic Solar Cells with an Efficiency of 10.2% and an Energy Loss of 0.59 eV Based on a Thieno[3,4-c]Pyrrole-4,6-dione-Containing Wide Band Gap Polymer Donor.

PubMed

Hadmojo, Wisnu Tantyo; Wibowo, Febrian Tri Adhi; Ryu, Du Yeol; Jung, In Hwan; Jang, Sung-Yeon

2017-09-27

Although the combination of wide band gap polymer donors and narrow band gap small-molecule acceptors achieved state-of-the-art performance as bulk heterojunction (BHJ) active layers for organic solar cells, there have been only several of the wide band gap polymers that actually realized high-efficiency devices over >10%. Herein, we developed high-efficiency, low-energy-loss fullerene-free organic solar cells using a weakly crystalline wide band gap polymer donor, PBDTTPD-HT, and a nonfullerene small-molecule acceptor, ITIC. The excessive intermolecular stacking of ITIC is efficiently suppressed by the miscibility with PBDTTPD-HT, which led to a well-balanced nanomorphology in the PBDTTPD-HT/ITIC BHJ active films. The favorable optical, electronic, and energetic properties of PBDTTPD-HT with respect to ITIC achieved panchromatic photon-to-current conversion with a remarkably low energy loss (0.59 eV).

Inter-band optoelectronic properties in quantum dot structure of low band gap III-V semiconductors

NASA Astrophysics Data System (ADS)

Dey, Anup; Maiti, Biswajit; Chanda Sarkar, Debasree

2014-04-01

A generalized theory is developed to study inter-band optical absorption coefficient (IOAC) and material gain (MG) in quantum dot structures of narrow gap III-V compound semiconductor considering the wave-vector (k→) dependence of the optical transition matrix element. The band structures of these low band gap semiconducting materials with sufficiently separated split-off valance band are frequently described by the three energy band model of Kane. This has been adopted for analysis of the IOAC and MG taking InAs, InSb, Hg1-xCdxTe, and In1-xGaxAsyP1-y lattice matched to InP, as example of III-V compound semiconductors, having varied split-off energy band compared to their bulk band gap energy. It has been found that magnitude of the IOAC for quantum dots increases with increasing incident photon energy and the lines of absorption are more closely spaced in the three band model of Kane than those with parabolic energy band approximations reflecting the direct the influence of energy band parameters. The results show a significant deviation to the MG spectrum of narrow-gap materials having band nonparabolicity compared to the parabolic band model approximations. The results reflect the important role of valence band split-off energies in these narrow gap semiconductors.

Oligothiophene-Indandione-Linked Narrow-Band Gap Molecules: Impact of π-Conjugated Chain Length on Photovoltaic Performance.

PubMed

Komiyama, Hideaki; To, Takahiro; Furukawa, Seiichi; Hidaka, Yu; Shin, Woong; Ichikawa, Takahiro; Arai, Ryota; Yasuda, Takuma

2018-04-04

Solution-processed organic solar cells (OSCs) based on narrow-band gap small molecules hold great promise as next-generation energy-converting devices. In this paper, we focus on a family of A-π-D-π-A-type small molecules, namely, BDT- nT-ID ( n = 1-4) oligomers, consisting of benzo[1,2- b:4,5- b']dithiophene (BDT) as the central electron-donating (D) core, 1,3-indandione (ID) as the terminal electron-accepting (A) units, and two regioregular oligo(3-hexylthiophene)s ( nT) with different numbers of thiophene rings as the π-bridging units, and elucidate their structure-property-function relationships. The effects of the length of the π-bridging nT units on the optical absorption, thermal behavior, morphology, hole mobility, and OSC performance were systematically investigated. All oligomers exhibited broad and intense visible photoabsorption in the 400-700 nm range. The photovoltaic performances of bulk heterojunction OSCs based on BDT- nT-IDs as donors and a fullerene derivative as an acceptor were studied. Among these oligomers, BDT-2T-ID, incorporating bithiophene as the π-bridging units, showed better photovoltaic performance with a maximum power conversion efficiency as high as 6.9% under AM 1.5G illumination without using solvent additives or postdeposition treatments. These favorable properties originated from the well-developed interpenetrating network morphology of BDT-2T-ID, with larger domain sizes in the photoactive layer. Even though all oligomers have the same A-D-A main backbone, structural modulation of the π-bridging nT length was found to impact their self-organization and nanostructure formation in the solid state, as well as the corresponding OSC device performance.

Healthier Students Are Better Learners: High-Quality, Strategically Planned, and Effectively Coordinated School Health Programs Must Be a Fundamental Mission of Schools to Help Close the Achievement Gap

ERIC Educational Resources Information Center

Basch, Charles E.

2011-01-01

Objective: To discuss implications for educational policy and practice relevant to closing the achievement gap based on the literature review and synthesis presented in 7 articles of the October 2011 special issue of the "Journal of School Health". Methods: Implications for closing the achievement gap are drawn from analyses of current literature.…

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…

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

ERIC Educational Resources Information Center

Ikpa, Vivian W.; McGuire, C. Kent

2009-01-01

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

The gap in scientific knowledge and role of science communication in South Korea.

PubMed

Chang, Jeong-Heon; Kim, Sei-Hill; Kang, Myung-Hyun; Shim, Jae Chul; Ma, Dong Hoon

2017-01-01

Using data from a national survey of South Koreans, this study explores the role of science communication in enhancing three different forms of scientific knowledge ( factual, procedural, and subjective). We first assess learning effects, looking at the extent to which citizens learn science from different channels of communication (interpersonal discussions, traditional newspapers, television, online newspapers, and social media). We then look into the knowledge gap hypothesis, investigating how different communication channels can either widen or narrow the gap in knowledge between social classes. Television was found to function as a "knowledge leveler," narrowing the gap between highly and less educated South Koreans. The role of online newspapers in science learning is pronounced in our research. Reading newspapers online indicated a positive relationship to all three measures of knowledge. Contrary to the knowledge-leveling effect of television viewing, reading online newspapers was found to increase, rather than decrease, the gap in knowledge. Implications of our findings are discussed in detail.

Narrow-linewidth Q-switched random distributed feedback fiber laser.

PubMed

Xu, Jiangming; Ye, Jun; Xiao, Hu; Leng, Jinyong; Wu, Jian; Zhang, Hanwei; Zhou, Pu

2016-08-22

A narrow-linewidth Q-switched random fiber laser (RFL) based on a half-opened cavity, which is realized by narrow-linewidth fiber Bragg grating (FBG) and a section of 3 km passive fiber, has been proposed and experimentally investigated. The narrow-linewidth lasing is generated by the spectral filtering of three FBGs with linewidth of 1.21 nm, 0.56 nm, and 0.12 nm, respectively. The Q switching of the distributed cavity is achieved by placing an acousto-optical modulator (AOM) between the FBG and the passive fiber. The maximal output powers of the narrow-linewidth RFLs with the three different FBGs are 0.54 W, 0.27 W, and 0.08 W, respectively. Furthermore, the repetition rates of the output pulses are 500 kHz, and the pulse durations are about 500 ns. The corresponding pulse energies are about 1.08 μJ, 0.54 μJ, and 0.16 μJ, accordingly. The linewidth of FBG can influence the output characteristics in full scale. The narrower the FBG, the higher the pump threshold; the lower the output power at the same pump level, the more serious the linewidth broadening; and thus the higher the proportion of the CW-ground exists in the output pulse trains. Thanks to the assistance of the band-pass filter (BPF), the proportion of the CW-ground of narrow-linewidth Q-switched RFL under the relative high-pump-low-output condition can be reduced effectively. The experimental results indicate that it is challenging to demonstrate a narrow-linewidth Q-switched RFL with high quality output. But further power scaling and linewidth narrowing is possible in the case of operating parameters, optimization efforts, and a more powerful pump source. To the best of our knowledge, this is the first demonstration of narrow-linewidth generation in a Q-switched RFL.

In One Voice: Mainstream and ELL Teachers Work Side-by-Side in the Classroom, Teaching Language through Content

ERIC Educational Resources Information Center

Pardini, Priscilla

2006-01-01

Narrowing the achievement gap between students who are native English speakers and those learning English as a second language is one of the biggest challenges facing U.S. educators. This article discusses the approaches used by the Saint Paul (Minn.) Public Schools in narrowing this achievement gap. Saint Paul (Minn.) Public Schools has one of…

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…

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. © 2014 S. L. Eddy et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Vibration-tolerant narrow-linewidth semiconductor disk laser using novel frequency-stabilisation schemes

NASA Astrophysics Data System (ADS)

Hunter, Craig R.; Jones, Brynmor E.; Schlosser, Peter; Sørensen, Simon Toft; Strain, Michael J.; McKnight, Loyd J.

2018-02-01

This paper will present developments in narrow-linewidth semiconductor-disk-laser systems using novel frequencystabilisation schemes for reduced sensitivity to mechanical vibrations, a critical requirement for mobile applications. Narrow-linewidth single-frequency lasers are required for a range of applications including metrology and highresolution spectroscopy. Stabilisation of the laser was achieved using a monolithic fibre-optic ring resonator with free spectral range of 181 MHz and finesse of 52 to act as passive reference cavity for the laser. Such a cavity can operate over a broad wavelength range and is immune to a wide band of vibrational frequency noise due to its monolithic implementation. The frequency noise of the locked system has been measured and compared to typical Fabry-Perotlocked lasers using vibration equipment to simulate harsh environments, and analysed here. Locked linewidths of < 40 kHz have been achieved. These developments offer a portable, narrow-linewidth laser system for harsh environments that can be flexibly designed for a range of applications.

Fabrication of controllably variable sub-100  nm gaps in silver nanowires by photothermal-induced stress.

PubMed

Ghosh, Pintu; Lu, Jinsheng; Luo, Hao; Xu, Ziquan; Yan, Xiaoyuan; Wang, Yewu; Lu, Jun; Qiu, Min; Li, Qiang

2018-05-15

A technique to fabricate nanogaps with controllably variable gap width in silver (Ag) nanowires (NWs) by photothermal-induced stress utilizing a focused continuous-wave laser (532 nm) is presented. For the case of an Ag NW on gold thin film, a gap width starting from ∼20  nm is achieved with a critical minimum power (CMP) of about 160 mW, whereas in the case of an Ag NW placed on top of a zinc oxide NW, the attained gap width is as small as a few nm (<10  nm) with a CMP of only ∼100  mW. In both cases, the CMP is much lower as compared to the required CMP (∼280  mW) for an Ag NW placed on a bare silica substrate. The photothermal-induced stress combined with Rayleigh instability, melting, and sublimation of Ag aids in breaking the Ag NW. In particular, the former one plays a key role in attaining an extremely narrow gap. This technique to fabricate sub-100 nm nanogaps in metal NWs can be extensively implemented in fabrication and maintenance of nanomechanical, nanoplasmonic, and nanoelectronic devices.

Instruction, Teacher–Student Relations, and Math Achievement Trajectories in Elementary School

PubMed Central

Crosnoe, Robert; Morrison, Fred; Burchinal, Margaret; Pianta, Robert; Keating, Daniel; Friedman, Sarah L.; Clarke-Stewart, K. Alison

2010-01-01

Children enter elementary school with widely different skill levels in core subjects. Whether because of differences in aptitude or in preparedness, these initial skill differences often translate into systematic disparities in achievement over time. How can teachers reduce these disparities? Three possibilities are to offer basic skills training, to expose students to higher order instruction, or to provide socioemotional support. Repeated measures analyses of longitudinal data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Study of Early Child Care and Youth Development revealed that children with low, average, or high math skills prior to elementary school followed different but parallel trajectories of math achievement up through fifth grade. When enrolled in classes with inference-based instruction, however, the initially least skilled children narrowed the achievement gap as long as they did not have conflictual relations with their teachers. They did not make this kind of progress if they were in classes focused exclusively on basic skills instruction or if they were in inference-focused classes but had conflictual relations with teachers. PMID:20657743

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.…

Charpy V-notch properties and microstructures of narrow gap ferritic welds of a quenched and tempered steel plate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, G.L.F.; Herfurth, G.

1998-11-01

Multipass welds of quenched and tempered 50-mm-thick steel plate have been deposited by a single wire narrow gap process using both gas metal arc welding (GMAW) and submerged arc welding (SAW). Of the five welds, two reported much lower Charpy V-notch (CVN) values when tested at {minus} 20 C. The CVN toughness did not correlate with either the welding process or whether the power source was pulsed or nonpulsed. The only difference in the ferritic microstructure between the two welds of low Charpy values and the three of high values was the percentage of acicular ferrite. There was no effectmore » of the percentage of as-deposited reheated zones intersected by the Charpy notch or the microhardness of the intercellular-dendritic regions. In all welds, austenite was the microconstituent between the ferrite laths. The percentage of acicular ferrite correlated with the presence of MnO, TiO{sub 2}, {gamma} Al{sub 2}O{sub 3}, or MnO. Al{sub 2}O{sub 3} as the predominant crystalline compound in the oxide inclusions. In turn, the crystalline compound depended on the aluminum-to-titanium ratio in both the weld deposits and the oxide inclusions. In addition to the presence of less acicular ferrite, the two welds that showed lower Charpy values also reported more oxide inclusions greater than 1 {micro}m in diameter. The combination of more oxide inclusions greater than 1 {micro}m and less acicular ferrite is considered to be the explanation for the lower Charpy values.« less

Medicare Program Associated With Narrowing Hospital Readmission Disparities Between Black And White Patients.

PubMed

Figueroa, José F; Zheng, Jie; Orav, E John; Epstein, Arnold M; Jha, Ashish K

2018-04-01

The Hospital Readmissions Reduction Program has been associated with improvements in readmission rates, yet little is known about its effect on racial disparities. We compared trends in thirty-day readmission rates for congestive heart failure, acute myocardial infarction, and pneumonia among non-Hispanic whites versus non-Hispanic blacks, and among minority-serving hospitals versus others. During the penalty-free implementation period (April 2010-September 2012), readmission rates improved over pre-implementation trends (January 2007-March 2010) for both whites and blacks, with a significantly greater decline among blacks than among whites (-0.45 percent versus -0.36 percent per quarter, respectively). In the period October 2012-December 2014, after penalties began, readmission improvements slowed for both races. Following a similar pattern, minority-serving hospitals saw greater reductions in readmissions than other hospitals did. Despite the narrowing of the two race-based gaps after announcement of the Hospital Readmissions Reduction Program, both persist. It remains to be seen whether new policy efforts will narrow these gaps and reduce the disproportionately high penalties that minority-serving hospitals face.

Media use and HIV/AIDS knowledge: a knowledge gap perspective.

PubMed

Bekalu, Mesfin Awoke; Eggermont, Steven

2014-12-01

Despite the widespread utilization of the mass media in HIV/AIDS prevention, little is known about the knowledge gap that results from disparities in mass media use. This study examined the relationship between HIV/AIDS-related mass media use and HIV/AIDS-related knowledge among urban and rural residents of northwestern Ethiopia. A hierarchical regression analysis indicated that HIV/AIDS-related mass media use has both sequestering and mainstreaming effects in certain segments of the study population, although it was not a significant predictor of HIV/AIDS-related knowledge in the total population. The knowledge gaps between individuals with high and low education and between individuals who experience high and low levels of interpersonal communication about HIV/AIDS narrowed as HIV/AIDS-related media use increased, but the gap between urban and rural residents widened. The widening gap could be explained by differences in perceptions of information salience and several theoretical assumptions. Current mass media information campaigns, which are often prepared and broadcast from urban centers, may not only fail to improve the HIV/AIDS knowledge of the rural populace but also put rural populations at a disadvantage relative to their urban counterparts. Communication interventions informed by socioecological models might be helpful to redress and/or narrow the widening knowledge gap between urban and rural residents. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Microstructure of a safe-end dissimilar metal weld joint (SA508-52-316L) prepared by narrow-gap GTAW

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ming, Hongliang

The microstructure, residual strain and interfacial chemical composition distribution of a safe-end dissimilar metal weld joint (DMWJ, SA508-52-316L) prepared by narrow-gap gas-tungsten arc welding (NG-GTAW) were studied by optical microscope (OM) and scanning electron microscope equipped with an energy dispersive X-ray microanalysis (SEM/EDX) and an electron back scattering diffraction (EBSD) system. Complex microstructure and chemical composition distribution are found, especially at the SA508-52 interface and the 52-316L interface. In brief, a complicated microstructure transition exists within the SA508 heat affected zone (HAZ); the residual strain, the fraction of high angle random grain boundaries and low angle boundaries decrease with increasingmore » the distance from the fusion boundary in 316L HAZ; neither typical type II boundary nor obvious carbon-depleted zone is found near the SA508-52 interface; dramatic and complicated changes of the contents of the main elements, Fe, Cr and Ni, are observed at the distinct interfaces, especially at the SA508-52 interface. No carbon concentration is found at the SA508-52 interface. - Highlights: •Residual strain and GBCD change as a function of the distance from FB in 316L HAZ. •Neither type II boundary nor obvious carbon-depleted zone is found in SA508 HAZ. •No carbon concentration is found at the SA508-52 interface. •The middle part of the DMWJ has the highest residual strain.« less

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…

Ultra-narrow-linewidth Brillouin/erbium fiber laser

NASA Astrophysics Data System (ADS)

Chen, Mo; Wang, Chenyu; Wang, Jianfei; Luo, Hong; Meng, Zhou

2018-02-01

Ultra-narrow-linewidth lasers are of great interest in many applications, such as precise spectroscopy, optical communications, and sensors. Stimulated Brillouin scattering (SBS), as one of the main nonlinear effects in fibers, is capable of generating narrow-linewidth light emission. We establish a compact Brillouin/erbium fiber laser (BEFL) utilizing 4-m erbium-doped fiber as both the Brillouin gain and linear media. A 360-kHz-linewidth laser diode is injected into the cavity as the Brillouin pump (BP) light and generates Brillouin Stokes lasing light. Both of the phase noise of the BP and BEFL output are measured by a high-accuracy unbalanced Michelson interferometer. It is demonstrated that 53- dB phase noise reduction is achieved after the BP is transferred into Brillouin Stokes emission. The linewidth of the BEFL is indicated at Hz-range by both calculation and experiment.

Edge currents shunt the insulating bulk in gapped graphene

NASA Astrophysics Data System (ADS)

Zhu, M. J.; Kretinin, A. V.; Thompson, M. D.; Bandurin, D. A.; Hu, S.; Yu, G. L.; Birkbeck, J.; Mishchenko, A.; Vera-Marun, I. J.; Watanabe, K.; Taniguchi, T.; Polini, M.; Prance, J. R.; Novoselov, K. S.; Geim, A. K.; Ben Shalom, M.

2017-02-01

An energy gap can be opened in the spectrum of graphene reaching values as large as 0.2 eV in the case of bilayers. However, such gaps rarely lead to the highly insulating state expected at low temperatures. This long-standing puzzle is usually explained by charge inhomogeneity. Here we revisit the issue by investigating proximity-induced superconductivity in gapped graphene and comparing normal-state measurements in the Hall bar and Corbino geometries. We find that the supercurrent at the charge neutrality point in gapped graphene propagates along narrow channels near the edges. This observation is corroborated by using the edgeless Corbino geometry in which case resistivity at the neutrality point increases exponentially with increasing the gap, as expected for an ordinary semiconductor. In contrast, resistivity in the Hall bar geometry saturates to values of about a few resistance quanta. We attribute the metallic-like edge conductance to a nontrivial topology of gapped Dirac spectra.

Flexion and extension gaps created by the navigation-assisted gap technique show small acceptable mismatches and close mutual correlations.

PubMed

Lee, Dae-Hee; Shin, Young-Soo; Jeon, Jin-Ho; Suh, Dong-Won; Han, Seung-Beom

2014-08-01

The aim of this study was to investigate the mechanism underlying the development of gap differences in total knee arthroplasty using the navigation-assisted gap technique and to assess whether these gap differences have statistical significance. Ninety-two patients (105 knees) implanted with cruciate-retaining prostheses using the navigation-assisted gap balancing technique were prospectively analysed. Medial extension and flexion gaps and lateral extension and flexion gaps were measured at full extension and at 90° of flexion. Repeated measures analysis of variance was used to compare the mean values of these four gaps. The correlation coefficient between each pair of gaps was assessed using Pearson's correlation analysis. Mean intra-operative medial and lateral extension gaps were 20.6 ± 2.1 and 21.7 ± 2.2 mm, respectively, and mean intra-operative medial and lateral flexion gaps were 21.6 ± 2.7 and 22.1 ± 2.5 mm, respectively. The pairs of gaps differed significantly (P < 0.05 each), except for the difference between the medial flexion and lateral extension gaps (n.s.). All four gaps were significantly correlated with each other, with the highest correlation between the medial and lateral flexion gaps (r = 0.890, P < 0.001) and the lowest between the medial flexion and lateral extension gaps (r = 0.701, P < 0.001). Medial and lateral flexion and extension gaps created using the navigation-assisted gap technique differed significantly, although the differences between them were <2 mm, and the gaps were closely correlated. These narrow ranges of statistically acceptable gap differences and the strong correlations between gaps should be considered by surgeons, as should the risks of soft tissue over-release or unintentional increases in extension or flexion gap after preparation of the other gap.

Zero-gap semiconductor to excitonic insulator transition in Ta2NiSe5

PubMed Central

Lu, Y. F.; Kono, H.; Larkin, T. I.; Rost, A. W.; Takayama, T.; Boris, A. V.; Keimer, B.; Takagi, H.

2017-01-01

The excitonic insulator is a long conjectured correlated electron phase of narrow-gap semiconductors and semimetals, driven by weakly screened electron–hole interactions. Having been proposed more than 50 years ago, conclusive experimental evidence for its existence remains elusive. Ta2NiSe5 is a narrow-gap semiconductor with a small one-electron bandgap EG of <50 meV. Below TC=326 K, a putative excitonic insulator is stabilized. Here we report an optical excitation gap Eop ∼0.16 eV below TC comparable to the estimated exciton binding energy EB. Specific heat measurements show the entropy associated with the transition being consistent with a primarily electronic origin. To further explore this physics, we map the TC–EG phase diagram tuning EG via chemical and physical pressure. The dome-like behaviour around EG∼0 combined with our transport, thermodynamic and optical results are fully consistent with an excitonic insulator phase in Ta2NiSe5. PMID:28205553

Can Community and School-Based Supports Improve the Achievement of First-Generation Immigrant Children Attending High-Poverty Schools?

PubMed

Dearing, Eric; Walsh, Mary E; Sibley, Erin; Lee-St John, Terry; Foley, Claire; Raczek, Anastacia E

2016-05-01

Using a quasi-experimental design, the effects of a student support intervention were estimated for the math and reading achievement of first-generation immigrant children (n = 667, M = 11.05 years of age) attending high-poverty, urban elementary schools. The intervention was designed to help schools identify developmental strengths and barriers to learning and, in turn, connect children to community and school supports aligned with their strengths and needs. By exploiting within-school changes in the implementation of the intervention, the present study revealed statistically and practically significant treatment effects indicating improvements in math and reading achievement at the end of elementary school. In addition, the intervention appears to considerably narrow achievement gaps between English language learners and immigrant children proficient in English. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Exploring the gender gap in healthcare management.

PubMed

Weil, P; Haddock, C C; Barowsky, D

1996-01-01

A 1990 study by ACHE and the University of Iowa compared the career attainments and attitudes of a group of male and female healthcare executives. The research showed that among men and women who had entered the field at the same time and had achieved similar educational levels, women did not fare as well as men in terms of salary, position level, or job satisfaction. A follow-up to this study, which consisted of two parts, was conducted in 1995 by ACHE, the University of Alabama at Birmingham, and Lamalie Amrop International to learn whether the gender gap had narrowed. The 1990 study divided respondents into groups according to the year they entered healthcare management: 1971-1975, 1976-1980, or 1981-1985. The first part of the 1995 project was a replication study that paralleled the 1990 study, dividing a new pool of respondents into three groups: 1976-1980, 1981-1985, and 1986-1990. The second part of the follow-up project was a panel study, in which respondents from the 1990 study were surveyed again. Following are highlights from the 1995 study.

Stereotype susceptibility narrows the gender gap in imagined self-rotation performance.

PubMed

Wraga, Maryjane; Duncan, Lauren; Jacobs, Emily C; Helt, Molly; Church, Jessica

2006-10-01

Three studies examined the impact of stereotype messages on men's and women's performance of a mental rotation task involving imagined self-rotations. Experiment 1 established baseline differences between men and women; women made 12% more errors than did men. Experiment 2 found that exposure to a positive stereotype message enhanced women's performance in comparison with that of another group of women who received neutral information. In Experiment 3, men who were exposed to the same stereotype message emphasizing a female advantage made more errors than did male controls, and the magnitude of error was similar to that for women from Experiment 1. The results suggest that the gender gap in mental rotation performance is partially caused by experiential factors, particularly those induced by sociocultural stereotypes.

Is Perceptual Narrowing Too Narrow?

ERIC Educational Resources Information Center

Cashon, Cara H.; Denicola, Christopher A.

2011-01-01

There is a growing list of examples illustrating that infants are transitioning from having earlier abilities that appear more "universal," "broadly tuned," or "unconstrained" to having later abilities that appear more "specialized," "narrowly tuned," or "constrained." Perceptual narrowing, a well-known phenomenon related to face, speech, and…

Narrow and Deep Fano Resonances in a Rod and Concentric Square Ring-Disk Nanostructures

PubMed Central

Huo, Yanyan; Jia, Tianqing; Zhang, Yi; Zhao, Hua; Zhang, Shian; Feng, Donghai; Sun, Zhenrong

2013-01-01

Localized surface plasmon resonances (LSPRs) in metallic nanostructures have been studied intensely in the last decade. Fano interference is an important way to decrease the resonance linewidth and enhance the spectral detection resolution, but realizing a Fano lineshape with both a narrow linewidth and high spectral contrast-ratio is still challenging. Here we propose a metallic nanostructure consisting of a concentric square ring-disk (CSRD) nanostructure and an outside nanorod. Fano linewidth and spectral contrast ratio can be actively manipulated by adjusting the gap between the nanorod and CSRD, and by adjusting the gap between the ring and disk in CSRD. When the gap size in CSRD is reduced to 5 nm, the quadrupolar Fano linewidth is of 0.025 eV, with a contrast ratio of 80%, and the figure of merit reaches 15. PMID:24064596

Minding the Gap: Investing in a Skilled Manufacturing Workforce

ERIC Educational Resources Information Center

Richard, Alan

2015-01-01

Advanced manufacturing is growing and thriving in the United States. Companies are in great need of reliable employees who can communicate well, effectively make decisions, and are interested in long-term careers with opportunity for advancement. Employers have identified a need for a more robust talent pipeline to narrow America's skills gap--a…

Galaxy properties from J-PAS narrow-band photometry

NASA Astrophysics Data System (ADS)

Mejía-Narváez, A.; Bruzual, G.; Magris, C. G.; Alcaniz, J. S.; Benítez, N.; Carneiro, S.; Cenarro, A. J.; Cristóbal-Hornillos, D.; Dupke, R.; Ederoclite, A.; Marín-Franch, A.; de Oliveira, C. Mendes; Moles, M.; Sodre, L.; Taylor, K.; Varela, J.; Ramió, H. Vázquez

2017-11-01

We study the consistency of the physical properties of galaxies retrieved from spectral energy distribution (SED) fitting as a function of spectral resolution and signal-to-noise ratio (SNR). Using a selection of physically motivated star formation histories, we set up a control sample of mock galaxy spectra representing observations of the local Universe in high-resolution spectroscopy, and in 56 narrow-band and 5 broad-band photometry. We fit the SEDs at these spectral resolutions and compute their corresponding stellar mass, the mass- and luminosity-weighted age and metallicity, and the dust extinction. We study the biases, correlations and degeneracies affecting the retrieved parameters and explore the role of the spectral resolution and the SNR in regulating these degeneracies. We find that narrow-band photometry and spectroscopy yield similar trends in the physical properties derived, the former being considerably more precise. Using a galaxy sample from the Sloan Digital Sky Survey (SDSS), we compare more realistically the results obtained from high-resolution and narrow-band SEDs (synthesized from the same SDSS spectra) following the same spectral fitting procedures. We use results from the literature as a benchmark to our spectroscopic estimates and show that the prior probability distribution functions, commonly adopted in parametric methods, may introduce biases not accounted for in a Bayesian framework. We conclude that narrow-band photometry yields the same trend in the age-metallicity relation in the literature, provided it is affected by the same biases as spectroscopy, albeit the precision achieved with the latter is generally twice as large as with the narrow-band, at SNR values typical of the different kinds of data.

School accountability and the black-white test score gap.

PubMed

Gaddis, S Michael; Lauen, Douglas Lee

2014-03-01

Since at least the 1960s, researchers have closely examined the respective roles of families, neighborhoods, and schools in producing the black-white achievement gap. Although many researchers minimize the ability of schools to eliminate achievement gaps, the No Child Left Behind Act (NCLB) increased pressure on schools to do so by 2014. In this study, we examine the effects of NCLB's subgroup-specific accountability pressure on changes in black-white math and reading test score gaps using a school-level panel dataset on all North Carolina public elementary and middle schools between 2001 and 2009. Using difference-in-difference models with school fixed effects, we find that accountability pressure reduces black-white achievement gaps by raising mean black achievement without harming mean white achievement. We find no differential effects of accountability pressure based on the racial composition of schools, but schools with more affluent populations are the most successful at reducing the black-white math achievement gap. Thus, our findings suggest that school-based interventions have the potential to close test score gaps, but differences in school composition and resources play a significant role in the ability of schools to reduce racial inequality. Copyright © 2013 Elsevier Inc. All rights reserved.

"Mind the Gap": An Empirical Study of the Gap between Intention and Actual Usage of Corporate E-Learning Programmes in the Financial Industry

ERIC Educational Resources Information Center

Luor, Tainyi; Hu, Changya; Lu, His-Peng

2009-01-01

While numerous previous studies have focused on the use of some corporate e-learning programmes (CELP), little is known about the difference between users' pre-installation reactions to CELP and user's post-installation reactions to CELP. This study narrows the above gap with two investigations into a financial company's CELP. In the…

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…

Narrow-angle Astrometry with SUSI

NASA Astrophysics Data System (ADS)

Kok, Y.; Ireland, M. J.; Robertson, J. G.; Tuthill, P. G.; Warrington, B. A.; Tango, W. J.

2014-09-01

SUSI (Sydney University Stellar Interferometer) is currently being fitted with a 2nd beam combiner, MUSCA (Micro-arcsecond University of Sydney Companion Astrometry), for the purpose of narrow-angle astrometry. With an aim to achieve ˜10 micro-arcseconds of angular resolution at its best, MUSCA allows SUSI to search for planets around bright binary stars, which are its primary targets. While the first beam combiner, PAVO (Precision Astronomical Visible Observations), is used to track stellar fringes during an observation, MUSCA will be used to measure separations of binary stars. MUSCA is a Michelson interferometer and its setup at SUSI will be described in this poster.

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…

Health Equilibrium Initiative: a public health intervention to narrow the health gap and promote a healthy weight in Swedish children.

PubMed

Magnusson, Maria; Hallmyr Lewis, Moa; Smaga-Blom, Malgorzata; Lissner, Lauren; Pickering, Chris

2014-07-29

Inequity in health is a global concern. Even in Sweden there are considerable health gaps between different social groups, not least concerning life-style related conditions. Interventions drawing on Community-based participatory research (CBPR) have potential to build prerequisites for complex, supportive structures that constitute basis for implementation of sustainable health promoting programs. CBPR rests on principles of empowerment. The researchers are responsible for the scientific quality and that ethical standards are met. Health Equilibrium Initiative (HEI) aims at narrowing the health gap and promoting healthy weight in children; "healthy weight" including both anthropometric criteria and aspects having to do with self-esteem and self-efficacy. Evaluation objectives are to compare outcome between children in intervention and control areas, conduct health economic assessments (HEA) and evaluate the processes of the project. HEI is a repeated cross-sectional and longitudinal study. The Program Logic Model is based on Social Cognitive Theory and Intervention Mapping. Primary contact groups are children in disadvantaged communities. Core efforts are to confirm and convey knowledge, elucidate and facilitate on-going health work and support implementation of continuous health work. Socioeconomic status is assessed on area level by the parameters yearly average income, degree of employment, tertiary education and percent of inhabitants born in countries where violent conflicts recently have taken place or were ongoing. Anthropometry, food patterns, physical activity and belief in ability to affect health; together with learning, memory and attention assessment will be assessed in 350 children (born 2006). Examinations will be repeated after two years, forming the basis of a health economic analysis. The process evaluation procedure will use document analysis (such as structured reports from meetings and dialogues, school/workplaces policies and curriculum, food

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).

Stall in Women's Real Wage Growth Slows Progress in Closing the Wage Gap. Briefing Paper.

ERIC Educational Resources Information Center

Hartmann, Heidi; Whittaker, Julie

Since 1979, the wage gap between women and men has narrowed significantly, falling by more than 10 percent overall. The closing of the wage gap has slowed considerably in the 1990's, however, with women's real wages (adjusted for inflation) stagnating in recent year and men's wages continuing to decline. The lack of growth in both women's and…

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.

Electronic structure modifications and band gap narrowing in Zn0.95V0.05O

NASA Astrophysics Data System (ADS)

Ahad, Abdul; Majid, S. S.; Rahman, F.; Shukla, D. K.; Phase, D. M.

2018-04-01

We present here, structural, optical and electronic structure studies on Zn0.95V0.05O, synthesized using solid state method. Rietveld refinement of x-ray diffraction pattern indicates no considerable change in the lattice of doped ZnO. The band gap of doped sample, as calculated by Kubelka-Munk transformed reflectance spectra, has been found reduced compared to pure ZnO. Considerable changes in absorbance in UV-Vis range is observed in doped sample. V doping induced decrease in band gap is supported by x-ray absorption spectroscopy measurements. It is experimentally confirmed that conduction band edge in Zn0.95V0.05O has shifted towards Fermi level than in pure ZnO.

Workaholism: Bridging the Gap between Workplace, Sociocultural, and Family Research.

ERIC Educational Resources Information Center

Robinson, Bryan E.

2000-01-01

Article attempts to narrow the gap between studies of workaholism and human relations/organizational development, and workaholism and cross-cultural research and family counseling. Counselors are encouraged to be aware of implications of workaholism for clients, including burnout and family disintegration, and screen for it just as they would for…

Specific features of the spectra and relaxation kinetics of long-wavelength photoconductivity in narrow-gap HgCdTe epitaxial films and heterostructures with quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumyantsev, V. V., E-mail: rumyantsev@ipmras.ru; Ikonnikov, A. V.; Antonov, A. V.

2013-11-15

The spectra and relaxation kinetics of interband photoconductivity are investigated in narrow-gap Hg{sub 1-x}Cd{sub x}Te epitaxial films with x = 0.19-0.23 and in structures with HgCdTe-based quantum wells (QWs), having an interband-transition energy in the range of 30-90 meV, grown by molecular-beam epitaxy on GaAs (013) substrates. A long-wavelength sensitivity band caused by impurities or defects is found in the spectra of the structures with quantum wells in addition to the interband photoconductivity. It is shown that the lifetimes of nonequilibrium carriers in the structures with QWs is less than in bulk samples at the same optical-transition energy. From themore » measured carrier lifetimes, the ampere-watt responsivity and the equivalent noise power for a film with x = 0.19 at a wavelength of 19 {mu}m are estimated. When investigating the relaxation kinetics of the photoconductivity at 4.2 K in high excitation regime, it is revealed that radiative recombination is dominant over other mechanisms of nonequilibrium-carrier recombination.« less

Zero-gap semiconductor to excitonic insulator transition in Ta2NiSe5.

PubMed

Lu, Y F; Kono, H; Larkin, T I; Rost, A W; Takayama, T; Boris, A V; Keimer, B; Takagi, H

2017-02-16

The excitonic insulator is a long conjectured correlated electron phase of narrow-gap semiconductors and semimetals, driven by weakly screened electron-hole interactions. Having been proposed more than 50 years ago, conclusive experimental evidence for its existence remains elusive. Ta 2 NiSe 5 is a narrow-gap semiconductor with a small one-electron bandgap E G of <50 meV. Below T C =326 K, a putative excitonic insulator is stabilized. Here we report an optical excitation gap E op ∼0.16 eV below T C comparable to the estimated exciton binding energy E B . Specific heat measurements show the entropy associated with the transition being consistent with a primarily electronic origin. To further explore this physics, we map the T C -E G phase diagram tuning E G via chemical and physical pressure. The dome-like behaviour around E G ∼0 combined with our transport, thermodynamic and optical results are fully consistent with an excitonic insulator phase in Ta 2 NiSe 5 .

Tackling the Achievement Gap Head on: A Background and Discussion Paper for Community Groups Interested in Helping All Children Succeed in School

ERIC Educational Resources Information Center

Mueller, Dan

2005-01-01

The achievement gap is clearly visible throughout the school years, from grade-school test scores through high school graduation and higher education. It divides American Indian, Asian, Black, Latino, and White students, and it divides the economically advantaged from the disadvantaged regardless of their race/ethnicity. Under the federal No Child…

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…

Why the racial gap in life expectancy is declining in the United States

PubMed Central

Firebaugh, Glenn; Acciai, Francesco; Noah, Aggie J.; Prather, Christopher; Nau, Claudia

2014-01-01

BACKGROUND Blacks have lower life expectancy than whites in the United States. That disparity could be due to racial differences in the causes of death, with blacks being more likely to die of causes that affect the young, or it could be due to differences in the average ages of blacks and whites who die of the same cause. Prior studies fail to distinguish these two possibilities. OBJECTIVE In this study we determine how much of the 2000–10 reduction in the racial gap in life expectancy resulted from narrowing differences in the cause-specific mean age at death for blacks and whites, as opposed to changing cause-specific probabilities for blacks and whites. METHOD We introduce a method for separating the difference-in-probabilities and difference-inage components of group disparities in life expectancy. RESULTS Based on the new method, we find that 60% of the decline in the racial gap in life expectancy from 2000 to 2010 was attributable to reduction in the age component, largely because of declining differences in the age at which blacks and whites die of chronic diseases. CONCLUSION Our findings shed light on the sources of the declining racial gap in life expectancy in the United States, and help to identify where advances need to be made to achieve the goal of eliminating racial disparities in life expectancy. PMID:25580083

Success and failure in narrowing the disability employment gap: comparing levels and trends across Europe 2002-2014.

PubMed

Geiger, Ben Baumberg; van der Wel, Kjetil A; Tøge, Anne Grete

2017-12-02

International comparisons of the disability employment gap are an important driver of policy change. However, previous comparisons have used the European Union Statistics on Income and Living Conditions (EU-SILC), despite known comparability issues. We present new results from the higher-quality European Social Survey (ESS), compare these to EU-SILC and the EU Labour Force Survey (EU-LFS), and also examine trends in the disability employment gap in Europe over the financial crisis for the first time. For cross-sectional comparisons of 25 countries, we use micro-data for ESS and EU-SILC for 2012 and compare these to published EU-LFS 2011 estimates. For trend analyses, we use seven biannual waves of ESS (2002-2014) with a total sample size of 182,195, and annual waves of EU-SILC (2004-2014) with a total sample size of 2,412,791. (i) Cross-sectional: countries that have smaller disability employment gaps in one survey tend to have smaller gaps in the other surveys. Nevertheless, there are some countries that perform badly on the lower-quality surveys but better in the higher-quality ESS. (ii) Trends: the disability employment gap appears to have declined in ESS by 4.9%, while no trend is observed in EU-SILC - but this has come alongside a rise in disability in ESS. There is a need for investment in disability measures that are more comparable over time/space. Nevertheless, it is clear to policymakers there are some countries that do consistently well across surveys and measures (Switzerland), and others that do badly (Hungary).

A Better Way to Motivate Achievement

ERIC Educational Resources Information Center

Parker, Dennis

2012-01-01

Many low income, minority schools in California are within 100 points of closing the achievement gap, a prize worth working for no matter how inconvenient, uncomfortable, or risky. In this article, the author describes a better way to motivate educators to try new things that will accelerate student learning and close the achievement gap. The…

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…

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…

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)

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.

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.

Gaining on the Gap

ERIC Educational Resources Information Center

Smith, Robert G.

2010-01-01

About three-quarters of the 2009 graduates of the highly diverse Arlington, Virginia, Public Schools completed one or more Advanced Placement or International Baccalaureate courses during their high school careers. That figure serves as one indicator of a decade-long initiative to eliminate achievement gaps while raising achievement for all…

Achievement Gap Patterns of Grade 8 American Indian and Alaska Native Students in Reading and Math. Issues & Answers. REL 2009-No. 073

ERIC Educational Resources Information Center

Nelson, Steven; Greenough, Richard; Sage, Nicole

2009-01-01

Focusing on student proficiency in reading and math from 2003-04 to 2006-07, this report compares gaps in performance on state achievement tests between grade 8 American Indian and Alaska Native students and all other grade 8 students in 26 states serving large populations of American Indian and Alaska Native students. In response to a request by…

Gender gap or program gap? Students' negotiations of study practice in a course in electromagnetism

NASA Astrophysics Data System (ADS)

Andersson, Staffan; Johansson, Anders

2016-12-01

[This paper is part of the Focused Collection on Gender in Physics.] This study of achievement differences, as reflected by course grades, on a third-semester electromagnetism course at a Swedish research university was motivated by instructor concerns about gender inequalities. Quantitative analysis showed a gender gap in course grades between female and male students for the period of fall 2007 to spring 2013. Dynamics behind this gap were explored through interpretative discourse analysis on interviews of 21 students who had recently passed the course. A recurring pattern was identified in the interviews. Students described studying electromagnetism as either studying to pass or studying to learn. Their choice of practice was influenced by the significance recognized in the course, which primarily was discussed in relation to program affiliation. Students stressed that perceived differences, in their study context, were larger between students affiliated with different programs than between male and female students on the same program. This was supported by quantitative analysis of course grades in relation to study programs, where the grade difference between female and male students on the same program in most cases were not statistically significant. The gender gap in grades for the whole course was related to different achievements on different programs. Programs further from the discipline of physics had lower mean grades and also enrolled a larger fraction of female students. Society-wide gender differences in interest and study choice are reflected in the grades on this single course. These results displace the achievement gap from the level of individuals to that of programs, and the gender gap from a difference in achievement to a difference in study choice. We discuss the implications of this shift of perspective in relation to gender differences for both research and teaching.

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

Nature of the abnormal band gap narrowing in highly crystalline Zn1-xCoxO nanorods

NASA Astrophysics Data System (ADS)

Qiu, Xiaoqing; Li, Liping; Li, Guangshe

2006-03-01

Highly crystalline Zn1-xCoxO nanorods were prepared using a hydrothermal method. With increasing Co2+ dopant concentration, the lattice volume enlarged considerably, which is associated with the enhanced repulsive interactions of defect dipole moments on the wall surfaces. This lattice modification produced a significant decrease in band gap energies with its magnitude that followed the relationship, ΔEg=ΔE0•(e-x/B-1), where x and B are Co2+ dopant concentration and a constant, respectively. The abnormal band gap energies were indicated to originate from the sp-d exchange interactions that are proportional to the square of lattice volume.

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.

The Persistent Gap: Understanding Male-Female Salary Differentials amongst Canadian Academic Staff. CAUT Equity Review. Number 5

ERIC Educational Resources Information Center

Canadian Association of University Teachers, 2011

2011-01-01

There has been a long-standing concern amongst policymakers, economists, and trade unions over the persistent earnings gap between men and women in the Canadian labour market. Although this gap has narrowed over time, women's average hourly wages still remain about 16% lower than that earned by men. The reasons for this inequality in male and…

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

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.

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.

Field-Induced-Gap Infrared Detectors

NASA Technical Reports Server (NTRS)

Elliott, C. Thomas

1990-01-01

Semimetals become semiconductors under applied magnetic fields. New detectors require less cooling equipment because they operate at temperatures higher than liquid-helium temperatures required by extrinsic-semiconductor detectors. Magnetic fields for detectors provided by electromagnets based on recently-discovered high-transition-temperature superconducting materials. Detector material has to be semiconductor, in which photon absorbed by exciting electron/hole pair across gap Eg of forbidden energies between valence and conduction energy bands. Magnetic- and compositional-tuning effects combined to obtain two-absorber detector having narrow passband. By variation of applied magnetic field, passband swept through spectrum of interest.

The Supply and Demand of High-Achieving Hispanic Students

ERIC Educational Resources Information Center

Gurantz, Oded; Hurwitz, Michael; Smith, Jonathan

2016-01-01

Hispanics are the largest minority group in the United States, increasing almost six-fold from 1970 to 2014. Although Hispanics youth in the U.S. have traditionally had lower college attendance rates, some sources suggest a narrowing of the White-Hispanic postsecondary attendance gap over the last fifteen years. A key question is whether altering…

A narrow open tubular column for high efficiency liquid chromatographic separation

DOE PAGES

Chen, Huang; Yang, Yu; Qiao, Zhenzhen; ...

2018-01-01

We report a great feature of open tubular liquid chromatography when it is run using an extremely narrow ( e.g. , 2 μm inner diameter) open tubular column: more than 10 million plates per meter can be achieved in less than 10 min and under an elution pressure of ca. 20 bar.

A narrow open tubular column for high efficiency liquid chromatographic separation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Huang; Yang, Yu; Qiao, Zhenzhen

We report a great feature of open tubular liquid chromatography when it is run using an extremely narrow ( e.g. , 2 μm inner diameter) open tubular column: more than 10 million plates per meter can be achieved in less than 10 min and under an elution pressure of ca. 20 bar.

Photonic gaps in cholesteric elastomers under deformation

NASA Astrophysics Data System (ADS)

Cicuta, P.; Tajbakhsh, A. R.; Terentjev, E. M.

2004-07-01

Cholesteric liquid crystal elastomers have interesting and potentially very useful photonic properties. In an ideal monodomain configuration of these materials, one finds a Bragg reflection of light in a narrow wavelength range and a particular circular polarization. This is due to the periodic structure of the material along one dimension. In many practical cases, the cholesteric rubber possesses a sufficient degree of quenched disorder, which makes the selective reflection broadband. We investigate experimentally the problem of how the transmittance of light is affected by mechanical deformation of the elastomer, and the relation to changes in liquid crystalline structure. We explore a series of samples which have been synthesized with photonic stop gaps across the visible range. This allows us to compare results with detailed theoretical predictions regarding the evolution of stop gaps in cholesteric elastomers.

The NRSC and the FCC: Working To Change Policy and Procedure To Narrow the Distance between AM and FM.

ERIC Educational Resources Information Center

Huff, W. A. Kelly

In the mid-1980s, the National Association of Broadcasters (NAB) reformed the National Radio Systems Committee (NRSC) as a liaison between receiver manufacturers and amplitude modulation (AM) broadcasters to promote unity in upgrading AM transmission and reception, and to aid AM in narrowing the sound quality gap with frequency modulation (FM). In…

How can we further improve the LDL-cholesterol target level achievement rate based on the Hungarian MULTI GAP 2011 study results and considering the new European dyslipidemia guidelines?

PubMed

Mark, Laszlo; Paragh, György; Karadi, Istvan; Reiber, Istvan; Pados, Gyula; Kiss, Zoltan

2012-09-08

Despite the continuous improvement of the quality of lipid lowering therapy the achievement of target values is still not satisfactory, mainly in the very high cardiovascular risk category patients, where the goal of low density lipoprotein cholesterol (LDL-C) is 1.80 mmol/l. The trends in lipid lowering treatment of 17420 patients from different studies conducted between 2004 and 2010 were compared to that of 1626 patients of MULTI GAP (MULTI Goal Attainment Problem) 2011 treated by general practitioners (GPs) and specialists. In MULTI GAP 2011 the mean LDL-C level ± SD) of patients treated by GPs was found to be 2.87 ±1.01 mmol/l, the target value of 2.50 was achieved by 40% of them, in the specialists' patients the mean LDL-C level proved to be 2.77 ±1.10 mmol/l and the achievement rate was 45%. In the 2.50 mmol/l achievement rate of GPs' patients a satisfactory improvement was observed in the studied years, but the 1.80 mmol/l LDL-C goal in 2011 was attained only in 11% of very high risk cases. There was a linear correlation between the patient compliance estimated by the physicians and the LDL-C achievement rate. As the number of very high risk category patients has been increased according to the new European dyslipidemia guidelines, growing attention needs to be placed on attainment of the 1.80 mmol/l LDL-C level. Based on the results of the MULTI GAP studies, improving patients' adherence and the continuous training of physicians are necessary.

The Narrow-Line Region of Narrow-Line Seyfert 1 Galaxies

NASA Astrophysics Data System (ADS)

Rodríguez-Ardila, A.; Binette, Luc; Pastoriza, Miriani G.; Donzelli, Carlos J.

2000-08-01

This work studies the optical emission-line properties and physical conditions of the narrow-line region (NLR) of seven narrow-line Seyfert 1 galaxies (NLS1's) for which high signal-to-noise ratio spectroscopic observations were available. The resolution is 340 km s-1 (at Hα) over the wavelength interval 3700-9500 Å, enabling us to separate the broad and narrow components of the permitted emission lines. Our results show that the flux carried out by the narrow component of Hβ is, on average, 50% of the total line flux. As a result, the [O III] λ5007/Hβ ratio emitted in the NLR varies from 1 to 5, instead of the universally adopted value of 10. This has strong implications for the required spectral energy distribution that ionizes the NLR gas. Photoionization models that consider a NLR composed of a combination of matter-bounded and ionization-bounded clouds are successful at explaining the low [O III] λ5007/Hβ ratio and the weakness of low-ionization lines of NLS1's. Variation of the relative proportion of these two type of clouds nicely reproduces the dispersion of narrow-line ratios found among the NLS1 sample. Assuming similar physical model parameters of both NLS1's and the normal Seyfert 1 galaxy NGC 5548, we show that the observed differences of emission-line ratios between these two groups of galaxies can be explained, to a first approximation, in terms of the shape of the input ionizing continuum. Narrow emission-line ratios of NLS1's are better reproduced by a steep power-law continuum in the EUV-soft X-ray region, with spectral index α~-2. Flatter spectral indices (α~-1.5) match the observed line ratios of NGC 5548 but are unable to provide a good match to the NLS1 ratios. This result is consistent with ROSAT observations of NLS1's, which show that these objects are characterized by steeper power-law indices than those of Seyfert 1 galaxies with strong broad optical lines. Based on observations made at CASLEO. Complejo Astronómico El Leoncito

NEIGHBORHOOD CONTEXT AND THE GENDER GAP IN ADOLESCENT VIOLENT CRIME.

PubMed

Zimmerman, Gregory M; Messner, Steven F

2010-12-01

Although researchers consistently demonstrate that females engage in less criminal behavior than males across the life course, research on the variability of the gender gap across contexts is sparse. To address this issue, we examine the gender gap in self-reported violent crime among adolescents across neighborhoods. Multilevel models using data from the Project of Human Development in Chicago Neighborhoods (PHDCN) indicate that the gender gap in violent crime decreases as levels of neighborhood disadvantage increase. Further, the narrowing of the gender gap is explained by gender differences in peer influence on violent offending. Neighborhood disadvantage increases exposure to peer violence for both sexes, but peer violence has a stronger impact on violent offending for females than for males, producing the reduction in the gender gap at higher levels of disadvantage. We also find that the gender difference in the relationship between peer violence and offending is explained, in part, by (1) the tendency for females to have more intimate friendships than males, and (2) the moderating effect of peer intimacy on the relationship between peer violence and self-reported violent behavior.

Band gap engineering of BC2N for nanoelectronic applications

NASA Astrophysics Data System (ADS)

Lim, Wei Hong; Hamzah, Afiq; Ahmadi, Mohammad Taghi; Ismail, Razali

2017-12-01

The BC2N as an example of boron-carbon-nitride (BCN), has the analogous structure as the graphene and boron nitride. It is predicted to have controllable electronic properties. Therefore, the analytical study on the engineer-able band gap of the BC2N is carried out based on the schematic structure of BC2N. The Nearest Neighbour Tight Binding (NNTB) model is employed with the dispersion relation and the density of state (DOS) as the main band gap analysing parameter. The results show that the hopping integrals having the significant effect on the band gap, band structure and DOS of BC2N nanowire (BC2NNW) need to be taken into consideration. The presented model indicates consistent trends with the published computational results around the Dirac points with the extracted band gap of 0.12 eV. Also, it is distinguished that wide energy gap of boron nitride (BN) is successfully narrowed by this carbon doped material which assures the application of BC2N on the nanoelectronics and optoelectronics in the near future.

Pertussis Maternal Immunization: Narrowing the Knowledge Gaps on the Duration of Transferred Protective Immunity and on Vaccination Frequency

PubMed Central

Gaillard, María Emilia; Bottero, Daniela; Zurita, María Eugenia; Carriquiriborde, Francisco; Martin Aispuro, Pablo; Bartel, Erika; Sabater-Martínez, David; Bravo, María Sol; Castuma, Celina; Hozbor, Daniela Flavia

2017-01-01

Maternal safety through pertussis vaccination and subsequent maternal–fetal-antibody transfer are well documented, but information on infant protection from pertussis by such antibodies and by subsequent vaccinations is scarce. Since mice are used extensively for maternal-vaccination studies, we adopted that model to narrow those gaps in our understanding of maternal pertussis immunization. Accordingly, we vaccinated female mice with commercial acellular pertussis (aP) vaccine and measured offspring protection against Bordetella pertussis challenge and specific-antibody levels with or without revaccination. Maternal immunization protected the offspring against pertussis, with that immune protection transferred to the offspring lasting for several weeks, as evidenced by a reduction (4–5 logs, p < 0.001) in the colony-forming-units recovered from the lungs of 16-week-old offspring. Moreover, maternal-vaccination-acquired immunity from the first pregnancy still conferred protection to offspring up to the fourth pregnancy. Under the conditions of our experimental protocol, protection to offspring from the aP-induced immunity is transferred both transplacentally and through breastfeeding. Adoptive-transfer experiments demonstrated that transferred antibodies were more responsible for the protection detected in offspring than transferred whole spleen cells. In contrast to reported findings, the protection transferred was not lost after the vaccination of infant mice with the same or other vaccine preparations, and conversely, the immunity transferred from mothers did not interfere with the protection conferred by infant vaccination with the same or different vaccines. These results indicated that aP-vaccine immunization of pregnant female mice conferred protective immunity that is transferred both transplacentally and via offspring breastfeeding without compromising the protection boostered by subsequent infant vaccination. These results—though admittedly not

Detecting tree-fall gap disturbances in tropical rain forests with airborne lidar

NASA Astrophysics Data System (ADS)

Espirito-Santo, F. D. B.; Saatchi, S.; Keller, M.

2017-12-01

Forest inventory studies in the Amazon indicate a large terrestrial carbon sink. However, field plots may fail to represent forest mortality processes at landscape-scales of tropical forests. Here we characterize the frequency distribution of tree-fall gap disturbances in natural forests of tropical forests using a novel combination of forest inventory and airborne lidar data. We quantify gap size frequency distribution along vertical and horizontal dimensions in ten Neotropical forest canopies distributed across gradients of climate and landscapes using airborne lidar measurements. We assessed all canopy openings related to each class of tree height which yields a three dimensional structure of the distribution of canopy gaps. Gap frequency distributions from lidar CHM data vary markedly with minimum gap size thresholds, but we found that natural forest disturbances (tree-fall gaps) follow a power-law distribution with narrow range of power-law exponents (-1.2 to -1.3). These power-law exponents from gap frequency distributions provide insights into how natural forest disturbances are distributed over tropical forest landscape.

Falling Behind: New Evidence on the Black-White Achievement Gap

ERIC Educational Resources Information Center

Levitt, Steven D.; Fryer, Roland G.

2004-01-01

On average, black students typically score one standard deviation below white students on standardized tests--roughly the difference in performance between the average 4th grader and the average 8th grader. Historically, what has come to be known as the black-white test-score gap has emerged before children enter kindergarten and has tended to…

Ultra-narrow pulse generator with precision-adjustable pulse width

NASA Astrophysics Data System (ADS)

Fu, Zaiming; Liu, Hanglin

2018-05-01

In this paper, a novel ultra-narrow pulse generation approach is proposed. It is based on the decomposition and synthesis of pulse edges. Through controlling their relative delay, an ultra-narrow pulse could be generated. By employing field programmable gate array digital synthesis technology, the implemented pulse generator is with programmable ability. The amplitude of pulse signals is controlled by the radio frequency amplifiers and bias tees, and high precision can be achieved. More importantly, the proposed approach can break through the limitation of device's propagation delay and optimize the resolution and the accuracy of the pulse width significantly. The implemented pulse generator has two channels, whose minimum pulse width, frequency range, and amplitude range are 100 ps, 15 MHz-1.5 GHz, and 0.1 Vpp-1.8 Vpp, respectively. Both resolution of pulse width and channel delay are 1 ps, and amplitude resolution is 10 mVpp.

Black-White Differences in Achievement: The Importance of Wealth.

ERIC Educational Resources Information Center

Orr, Amy J.

2003-01-01

Argues that wealth can affect academic achievement, as well as help to explain the gap in black-white test scores and the racial achievement gap. Reveals that wealth affects achievement through its effect on the amount of cultural capital to which a child is exposed. Implications of the findings are discussed. (CAJ)

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

ERIC Educational Resources Information Center

What Works Clearinghouse, 2014

2014-01-01

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

Racial/Ethnic Test Score Gaps and the Urban Continuum

ERIC Educational Resources Information Center

Gagnon, Douglas J.; Mattingly, Marybeth J.

2018-01-01

Research is just beginning to describe with precision determinants of racial and ethnic achievement gaps. Work by Reardon, Kalogrides, and Shores found that factors such as parental income, parental education, and segregation are the strongest predictors of achievement gaps. In this study we expand this line of inquiry to examine the role of…

Teachers' perceptions of the effectiveness of an urban health sciences curriculum in closing the Black-White test score gap: A participatory case study

NASA Astrophysics Data System (ADS)

Prince, Joan Marie

1999-12-01

Over the past years, progress in Black academic achievement, particularly in the area of science, has generally slowed or ceased. According to the 1994 NAEP assessment, twelfth-grade Black students are performing at the level of White eighth-grade students in the discipline of science (Department of Education, 1996). These students, in their last year of required schooling, are about to graduate, yet they lag at least four years behind their white counterparts in science achievement. Despite the establishment and implementation of numerous science intervention programs, Black students still suffer from a disparate gap in standardized test score achievement. The purpose of this research is to investigate teachers' perceptions of the effectiveness of an urban sciences intervention tool that was designed to assist in narrowing the Black-White science academic achievement gap. Specifically, what factors affect teachers' personal sense of instructional efficacy, and how does this translate into their outcome expectancy for student academic success? A multiple-case, replicative design, grounded in descriptive theory, was selected for the study. Multiple sources of evidence were queried to provide robust findings. These sources included a validated health sciences self-efficacy instrument, an interview protocol, a classroom observation, and a review of archival material that included case study participants' personnel files and meeting minutes. A cross-comparative analytic approach was selected for interpretation (Yin, 1994). Findings indicate that teachers attribute the success or failure of educational intervention tools in closing the Black-White test score gap to a variety of internal and external factors. These factors included a perceived lack of both monetary and personal support by the school leadership, as well as a perceived lack of parental involvement which impacted negatively on student achievement patterns. The case study participants displayed a depressed

Gap solitons in Ginzburg-Landau media.

PubMed

Sakaguchi, Hidetsugu; Malomed, Boris A

2008-05-01

We introduce a model combining basic elements of conservative systems which give rise to gap solitons, i.e., a periodic potential and self-defocusing cubic nonlinearity, and dissipative terms corresponding to the complex Ginzburg-Landau (CGL) equation of the cubic-quintic type. The model may be realized in optical cavities with a periodic transverse modulation of the refractive index, self-defocusing nonlinearity, linear gain, and saturable absorption. By means of systematic simulations and analytical approximations, we find three species of stable dissipative gap solitons (DGSs), and also dark solitons. They are located in the first finite band gap, very close to the border of the Bloch band separating the finite and the semi-infinite gaps. Two species represent loosely and tightly bound solitons, in cases when the underlying Bloch band is, respectively, relatively broad or very narrow. These two families of stationary solitons are separated by a region of breathers. The loosely bound DGSs are accurately described by means of two approximations, which rely on the product of a carrier Bloch function and a slowly varying envelope, or reduce the model to CGL-Bragg equations. The former approximation also applies to dark solitons. Another method, based on the variational approximation, accurately describes tightly bound solitons. The loosely bound DGSs, as well as dark solitons, are mobile, and their collisions are quasielastic.

Race, Socioeconomic Status, and Implicit Bias: Implications for Closing the Achievement Gap

NASA Astrophysics Data System (ADS)

Schlosser, Elizabeth Auretta Cox

This study accessed the relationship between race, socioeconomic status, age and the race implicit bias held by middle and high school science teachers in Mobile and Baldwin County Public School Systems. Seventy-nine participants were administered the race Implicit Association Test (race IAT), created by Greenwald, A. G., Nosek, B. A., & Banaji, M. R., (2003) and a demographic survey. Quantitative analysis using analysis of variances, ANOVA and t-tests were used in this study. An ANOVA was performed comparing the race IAT scores of African American science teachers and their Caucasian counterparts. A statically significant difference was found (F = .4.56, p = .01). An ANOVA was also performed using the race IAT scores comparing the age of the participants; the analysis yielded no statistical difference based on age. A t-test was performed comparing the race IAT scores of African American teachers who taught at either Title I or non-Title I schools; no statistical difference was found between groups (t = -17.985, p < .001). A t-test was also performed comparing the race IAT scores of Caucasian teachers who taught at either Title I or non-Title I schools; a statistically significant difference was found between groups ( t = 2.44, p > .001). This research examines the implications of the achievement gap among African American and Caucasian students in science.

Where is the exact origin of narrow premature ventricular contractions manifesting qR in inferior wall leads?

PubMed

Zheng, Cheng; Li, Jin; Lin, Jia-Xuan; Wang, Lu-Ping; Lin, Jia-Feng

2016-04-04

In recent years, radiofrequency catheter ablation(RFCA) has been established as an effective therapy for idiopathic premature ventricular contractions (PVCs), however, its effect on the narrow PVCs (QRS duration < 130 msec) with qR pattern in inferior leads, may not been fully concluded. Characteristics of 12-lead electrocardiogram (ECG) and electrophysiologic recordings were analyzed in 40 patients with symptomatic PVCs manifesting narrow QRS complex with qR pattern in inferior leads. The procedure of RFCA was performed based on pace mapping and activation mapping. Among the 40 patients with narrow PVCs, complete elimination of PVCs was achieved by RFCA in 35 patients during a median follow-up period of 23 months. Successful ablation was achieved on 19 patients at the sites where earliest Purkinje potentials were recorded in left ventricular anterosuperior septum, thus PVCs arising from left anterior fascicle (LAF) were confirmed, for these PVCs, the QRS morphology were right bundle branch and left posterior fascicle block (RBBB + LPFB) with rightward axis, the average QRS duration 116.07 ± 7.96 ms, R or rsR'in lead V1,with transition zone ahead of lead V1 in precordial leads. Another 16 successful RFCA were achieved by energy delivery at interleaflet triangle(ILT) between right coronary cusp(RCC) and left coronary cusp(LCC) where no Purkinje potentials were recorded, for narrow PVCs arising from the L-RCC ILT, the QRS morphology were similar to the PVCs arising from LAF but much narrower in QRS duration (100.44 ± 3.49 vs. 116.07 ± 7.96 ms, p < 0.05), they were also R or Rs in lead V1 with the transition zone ahead of lead V1. For 5 symptomatic narrow PVCs failed to the procedure of RFCA, their electrocardiographic characteristics showed that the narrowest QRS duration (91.80 ± 6.94 vs. 100.44 ± 3.49, 116.07 ± 7.96 ms, p < 0.05), rs or rS (r/s or r/S≦1) morphology in lead V1 with the precordial transition zone behind lead V3. Most of idiopathic PVCs of

Study on airflow characteristics in the semi-closed irregular narrow flow channel

NASA Astrophysics Data System (ADS)

Jin, Yuzhen; Hu, Xiaodong; Zhu, Linhang; Hu, Xudong; Jin, Yingzi

2016-04-01

The air-jet loom is widely used in the textile industry. The interaction mechanism of airflow and yarn is not clear in such a narrow flow channel, the gas consumption is relatively large, the yarn motion is unstable and the weft insertion is often interrupted during the operation. In order to study the characteristics of the semi-closed flow field in profiled dents, the momentum conservation equation is modified and the model parameters and boundary conditions are set. Compared with the different r, the ratio of profiled dent's thickness and gap, the results show that the smaller the r is, the smaller the velocity fluctuations of the airflow is. When the angle of profiled dents α is close to zero, the diffusion of the airflow will be less. The experiment is also conducted to verify the result of the simulation with a high-speed camera and pressure sensor in profiled dents. The airflow characteristics in the semi-closed irregular narrow flow channel in the paper would provide the theoretical basis for optimizing the weft insertion process of the air-jet loom.

Widely tunable narrow-band coherent Terahertz radiation from an undulator at THU

NASA Astrophysics Data System (ADS)

Su, X.; Wang, D.; Tian, Q.; Liang, Y.; Niu, L.; Yan, L.; Du, Y.; Huang, W.; Tang, C.

2018-01-01

There is anxious demand for intense widely tunable narrow-band Terahertz (THz) radiation in scientific research, which is regarded as a powerful tool for the coherent control of matter. We report the generation of widely tunable THz radiation from a planar permanent magnet undulator at Tsinghua University (THU). A relativistic electron beam is compressed by a magnetic chicane into sub-ps bunch length to excite THz radiation in the undulator coherently. The THz frequency can be tuned from 0.4 THz to 10 THz continuously with narrow-band spectrums when the undulator gap ranges from 23 mm to 75 mm. The measured pulse THz radiation energy from 220 pC bunch is 3.5 μJ at 1 THz and tens of μJ pulse energy (corresponding peak power of 10 MW) can be obtained when excited by 1 nC beam extrapolated from the property of coherent radiation. The experimental results agree well with theoretical predictions, which demonstrates a suitable THz source for the many applications that require intense and widely tunable THz sources.

Closing the Knowledge Gap on Effective Professional Development

ERIC Educational Resources Information Center

Guskey, Thomas R.

2009-01-01

Achievement gaps concern educators at all levels today. Educators recognize the threats these gaps pose to education quality and equity, and they are working hard to close them--but an equally threatening gap in education with consequences just as serious is largely ignored. It influences every educational-improvement effort and seriously…

Faculty Development to Address the Achievement Gap

ERIC Educational Resources Information Center

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

2015-01-01

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

A Case Study to Explore Rigorous Teaching and Testing Practices to Narrow the Achievement Gap

ERIC Educational Resources Information Center

Isler, Tesha

2012-01-01

The problem examined in this study: Does the majority of teachers use rigorous teaching and testing practices? The purpose of this qualitative exploratory case study was to explore the classroom techniques of six effective teachers who use rigorous teaching and testing practices. The hypothesis for this study is that the examination of the…

Why "Gender" Disappeared from the Gender Gap: (Re-)Introducing Gender Identity Theory to Educational Gender Gap Research

ERIC Educational Resources Information Center

Vantieghem, Wendelien; Vermeersch, Hans; Van Houtte, Mieke

2014-01-01

Educational gender gap research tries to explain the differential achievement of boys and girls at secondary school, which manifests in many western countries. Several explanatory frameworks are used for this purpose, such as masculinities theory. In this review article, the history of educational gender gap research in Anglo-Saxon literature and…

The Impact of Rosenwald Schools on Black Achievement. WP 2009-26

ERIC Educational Resources Information Center

Aaronson, Daniel; Mazumder, Bhashkar

2009-01-01

The Black-White gap in completed schooling among Southern born men narrowed sharply between the World Wars after being stagnant from 1880 to 1910. We examine a large scale school construction project, the Rosenwald Rural Schools Initiative, which was designed to dramatically improve the educational opportunities for Southern rural Blacks. From…

Ultra-narrow-linewidth erbium-doped lasers on a silicon photonics platform

NASA Astrophysics Data System (ADS)

Li, Nanxi; Purnawirman, Purnawirman; Magden, E. Salih; Singh, Gurpreet; Singh, Neetesh; Baldycheva, Anna; Hosseini, Ehsan S.; Sun, Jie; Moresco, Michele; Adam, Thomas N.; Leake, Gerald; Coolbaugh, Douglas; Bradley, Jonathan D. B.; Watts, Michael R.

2018-02-01

We report ultra-narrow-linewidth erbium-doped aluminum oxide (Al2O3:Er3+) distributed feedback (DFB) lasers with a wavelength-insensitive silicon-compatible waveguide design. The waveguide consists of five silicon nitride (SiNx) segments buried under silicon dioxide (SiO2) with a layer Al2O3:Er3+ deposited on top. This design has a high confinement factor (> 85%) and a near perfect (> 98%) intensity overlap for an octave-spanning range across near infrared wavelengths (950-2000 nm). We compare the performance of DFB lasers in discrete quarter phase shifted (QPS) cavity and distributed phase shifted (DPS) cavity. Using QPS-DFB configuration, we obtain maximum output powers of 0.41 mW, 0.76 mW, and 0.47 mW at widely spaced wavelengths within both the C and L bands of the erbium gain spectrum (1536 nm, 1566 nm, and 1596 nm). In a DPS cavity, we achieve an order of magnitude improvement in maximum output power (5.43 mW) and a side mode suppression ratio (SMSR) of > 59.4 dB at an emission wavelength of 1565 nm. We observe an ultra-narrow linewidth of ΔνDPS = 5.3 +/- 0.3 kHz for the DPS-DFB laser, as compared to ΔγQPS = 30.4 +/- 1.1 kHz for the QPS-DFB laser, measured by a recirculating self-heterodyne delayed interferometer (RSHDI). Even narrower linewidth can be achieved by mechanical stabilization of the setup, increasing the pump absorption efficiency, increasing the output power, or enhancing the cavity Q.

1-kW monolithic narrow linewidth linear-polarized fiber laser at 1030 nm

NASA Astrophysics Data System (ADS)

Xu, Yang; Fang, Qiang; Cui, Xuelong; Hou, Bowen; Fu, Shijie; Xie, Zhaoxin; Shi, Wei

2018-02-01

We demonstrate an all-fiberized, linear-polarized, narrow spectral linewidth laser system with kilowatts-level output power at 1030 nm in master oscillator-power amplifier (MOPA) configuration. The laser system consists of a linear-polarized, narrow linewidth ( 28 GHz) fiber laser oscillator and two stages of linear-polarized fiber amplifiers. A 925 W linear-polarized fiber laser with a polarization extinction ratio (PER) of 15.2 dB and a spectral width of 60 GHz at the central wavelength of 1030.1 nm is achieved. Owing to the setting of the appropriate parameters for the laser, no indication of Stimulate Brillouin Scattering (SBS) is observed in the system. Moreover, thanks to the excellent quantum efficiency of the laser and the thightly coiling of the active fiber in the main amplifier, the mode instability (MI) is successfully avoided. As a result, the near diffraction-limited beam quality (M2<1.3) is achieved.

A Unifying Perspective on Oxygen Vacancies in Wide Band Gap Oxides.

PubMed

Linderälv, Christopher; Lindman, Anders; Erhart, Paul

2018-01-04

Wide band gap oxides are versatile materials with numerous applications in research and technology. Many properties of these materials are intimately related to defects, with the most important defect being the oxygen vacancy. Here, using electronic structure calculations, we show that the charge transition level (CTL) and eigenstates associated with oxygen vacancies, which to a large extent determine their electronic properties, are confined to a rather narrow energy range, even while band gap and the electronic structure of the conduction band vary substantially. Vacancies are classified according to their character (deep versus shallow), which shows that the alignment of electronic eigenenergies and CTL can be understood in terms of the transition between cavity-like localized levels in the large band gap limit and strong coupling between conduction band and vacancy states for small to medium band gaps. We consider both conventional and hybrid functionals and demonstrate that the former yields results in very good agreement with the latter provided that band edge alignment is taken into account.

Regulating thrombus growth and stability to achieve an optimal response to injury

PubMed Central

Brass, Lawrence F.; Wannemacher, Kenneth M.; Ma, Peisong; Stalker, Timothy J.

2012-01-01

An optimal platelet response to injury can be defined as one in which blood loss is restrained and haemostasis is achieved without the penalty of further tissue damage caused by unwarranted vascular occlusion. This brief review considers some of the ways in which thrombus growth and stability can be regulated so that an optimal platelet response can be achieved in vivo. Three related topics are considered. The first focuses on intracellular mechanisms that regulate the early events of platelet activation downstream of G protein coupled receptors for agonists such as thrombin, thromboxane A2 and ADP. The second considers the ways in which signalling events that are dependent on stable contacts between platelets can influence the state of platelet activation and thus affect thrombus growth and stability. The third focuses on the changes that are experienced by platelets as they move from their normal environment in freely-flowing plasma to a very different environment within the growing haemostatic plug, an environment in which the narrowing gaps and junctions between platelets not only facilitate communication, but also increasingly limit both the penetration of plasma and the exodus of platelet-derived bioactive molecules. PMID:21781243

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…

Giant topological nontrivial band gaps in chloridized gallium bismuthide.

PubMed

Li, Linyang; Zhang, Xiaoming; Chen, Xin; Zhao, Mingwen

2015-02-11

Quantum spin Hall (QSH) effect is promising for achieving dissipationless transport devices but presently is achieved only at extremely low temperature. Searching for the large-gap QSH insulators with strong spin-orbit coupling (SOC) is the key to increase the operating temperature. We demonstrate theoretically that this can be solved in the chloridized gallium bismuthide (GaBiCl2) monolayer, which has nontrivial gaps of 0.95 eV at the Γ point, and 0.65 eV for bulk, as well as gapless edge states in the nanoribbon structures. The nontrivial gaps due to the band inversion and SOC are robust against external strain. The realization of the GaBiCl2 monolayer will be beneficial for achieving QSH effect and related applications at high temperatures.

NEIGHBORHOOD CONTEXT AND THE GENDER GAP IN ADOLESCENT VIOLENT CRIME*

PubMed Central

Zimmerman, Gregory M.; Messner, Steven F.

2011-01-01

Although researchers consistently demonstrate that females engage in less criminal behavior than males across the life course, research on the variability of the gender gap across contexts is sparse. To address this issue, we examine the gender gap in self-reported violent crime among adolescents across neighborhoods. Multilevel models using data from the Project of Human Development in Chicago Neighborhoods (PHDCN) indicate that the gender gap in violent crime decreases as levels of neighborhood disadvantage increase. Further, the narrowing of the gender gap is explained by gender differences in peer influence on violent offending. Neighborhood disadvantage increases exposure to peer violence for both sexes, but peer violence has a stronger impact on violent offending for females than for males, producing the reduction in the gender gap at higher levels of disadvantage. We also find that the gender difference in the relationship between peer violence and offending is explained, in part, by (1) the tendency for females to have more intimate friendships than males, and (2) the moderating effect of peer intimacy on the relationship between peer violence and self-reported violent behavior. PMID:21709751

Gap-state engineering of visible-light-active ferroelectrics for photovoltaic applications.

PubMed

Matsuo, Hiroki; Noguchi, Yuji; Miyayama, Masaru

2017-08-08

Photoferroelectrics offer unique opportunities to explore light energy conversion based on their polarization-driven carrier separation and above-bandgap voltages. The problem associated with the wide bandgap of ferroelectric oxides, i.e., the vanishingly small photoresponse under visible light, has been overcome partly by bandgap tuning, but the narrowing of the bandgap is, in principle, accompanied by a substantial loss of ferroelectric polarization. In this article, we report an approach, 'gap-state' engineering, to produce photoferroelectrics, in which defect states within the bandgap act as a scaffold for photogeneration. Our first-principles calculations and single-domain thin-film experiments of BiFeO 3 demonstrate that gap states half-filled with electrons can enhance not only photocurrents but also photovoltages over a broad photon-energy range that is different from intermediate bands in present semiconductor-based solar cells. Our approach opens a promising route to the material design of visible-light-active ferroelectrics without sacrificing spontaneous polarization.Overcoming the optical transparency of wide bandgap of ferroelectric oxides by narrowing its bandgap tends to result in a loss of polarization. By utilizing defect states within the bandgap, Matsuo et al. report visible-light-active ferroelectrics without sacrificing polarization.

Trunk, head, and step characteristics during normal and narrow-based walking under deteriorated sensory conditions.

PubMed

Deshpande, Nandini; Zhang, Fang

2014-01-01

The ability to maintain stability in the frontal plane (medialateral direction) while walking is commonly included as a component of motor performance assessment. Postural control in the frontal plane may deteriorate faster and earlier with increasing age, compared to that in the sagittal plane (anteroposterior direction). Fifteen young (20-30 years old) and 15 older (>65 years old) healthy participants were recruited to investigate age-related differences in postural control during the normal and narrow-based walking when performed under suboptimal vestibular and lower limb somatosensory conditions achieved by galvanic stimulation and compliant surfaces, respectively. Gait speed decreased in the narrow-based walking condition, with larger decrease in the elderly (by 6%). In the elderly head roll increased with perturbed vestibular information in impaired somatosensory condition (by 40.70%). In both age groups trunk roll increased under impaired somatosensation in the narrow-based walking condition (by 43.62%) but not in normal walking condition. Older participants adopted a more cautious strategy characterized by lower walking speed when walking on a narrow base and exhibited deteriorated integrative ability of the CNS for head control. Accurate lower limb somatosensation may play a critical role in narrow-based walking.

II-VI Narrow-Bandgap Semiconductors for Optoelectronics

NASA Astrophysics Data System (ADS)

Baker, Ian

The field of narrow-gap II-VI materials is dominated by the compound semiconductor mercury cadmium telluride, (Hg1-x Cd x Te or MCT), which supports a large industry in infrared detectors, cameras and infrared systems. It is probably true to say that HgCdTe is the third most studied semiconductor after silicon and gallium arsenide. Hg1-x Cd x Te is the material most widely used in high-performance infrared detectors at present. By changing the composition x the spectral response of the detector can be made to cover the range from 1 μm to beyond 17 μm. The advantages of this system arise from a number of features, notably: close lattice matching, high optical absorption coefficient, low carrier generation rate, high electron mobility and readily available doping techniques. These advantages mean that very sensitive infrared detectors can be produced at relatively high operating temperatures. Hg1-x Cd x Te multilayers can be readily grown in vapor-phase epitaxial processes. This provides the device engineer with complex doping and composition profiles that can be used to further enhance the electro-optic performance, leading to low-cost, large-area detectors in the future. The main purpose of this chapter is to describe the applications, device physics and technology of II-VI narrow-bandgap devices, focusing on HgCdTe but also including Hg1-x Mn x Te and Hg1-x Zn x Te. It concludes with a review of the research and development programs into third-generation infrared detector technology (so-called GEN III detectors) being performed in centers around the world.

Anomalous Temperature Dependence of the Band Gap in Black Phosphorus.

PubMed

Villegas, Cesar E P; Rocha, A R; Marini, Andrea

2016-08-10

Black phosphorus (BP) has gained renewed attention due to its singular anisotropic electronic and optical properties that might be exploited for a wide range of technological applications. In this respect, the thermal properties are particularly important both to predict its room temperature operation and to determine its thermoelectric potential. From this point of view, one of the most spectacular and poorly understood phenomena is indeed the BP temperature-induced band gap opening; when temperature is increased, the fundamental band gap increases instead of decreases. This anomalous thermal dependence has also been observed recently in its monolayer counterpart. In this work, based on ab initio calculations, we present an explanation for this long known and yet not fully explained effect. We show that it arises from a combination of harmonic and lattice thermal expansion contributions, which are in fact highly interwined. We clearly narrow down the mechanisms that cause this gap opening by identifying the peculiar atomic vibrations that drive the anomaly. The final picture we give explains both the BP anomalous band gap opening and the frequency increase with increasing volume (tension effect).

Band gap bowing in NixMg1−xO

PubMed Central

Niedermeier, Christian A.; Råsander, Mikael; Rhode, Sneha; Kachkanov, Vyacheslav; Zou, Bin; Alford, Neil; Moram, Michelle A.

2016-01-01

Epitaxial transparent oxide NixMg1−xO (0 ≤ x ≤ 1) thin films were grown on MgO(100) substrates by pulsed laser deposition. High-resolution synchrotron X-ray diffraction and high-resolution transmission electron microscopy analysis indicate that the thin films are compositionally and structurally homogeneous, forming a completely miscible solid solution. Nevertheless, the composition dependence of the NixMg1−xO optical band gap shows a strong non-parabolic bowing with a discontinuity at dilute NiO concentrations of x < 0.037. Density functional calculations of the NixMg1−xO band structure and the density of states demonstrate that deep Ni 3d levels are introduced into the MgO band gap, which significantly reduce the fundamental gap as confirmed by optical absorption spectra. These states broaden into a Ni 3d-derived conduction band for x > 0.074 and account for the anomalously large band gap narrowing in the NixMg1−xO solid solution system. PMID:27503808

The research-practice gap: bridging the schism between eating disorder researchers and practitioners.

PubMed

Lilienfeld, Scott O; Ritschel, Lorie A; Lynn, Steven Jay; Brown, Amanda P; Cautin, Robin L; Latzman, Robert D

2013-07-01

The field of eating disorders (EDs) treatment has been beset by a marked disjunction between scientific evidence and clinical application. We describe the nature and scope of the research-practice gap in the ED field. We draw on surveys and broader literature to better understand the research-practice gap in ED treatment and reasons for resistance to evidence-based practice. We identify three sources of the research-practice gap: (1) attitudinal factors, (2) differences in the definition of "evidence," and (3) cognitive factors, especially naïve realism and confirmation bias. We affirm the role of science as a safeguard against human fallibility and as a means of bridging the research-practice gap, and delineate key principles of scientific thinking for ED researchers and practitioners. We conclude with proposals for narrowing the research-practice gap in ED treatment and enhancing the quality of interventions for ED clients. Copyright © 2013 Wiley Periodicals, Inc.

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…

Partially Filled Aperture Interferometric Telescopes: Achieving Large Aperture and Coronagraphic Performance

NASA Astrophysics Data System (ADS)

Moretto, G.; Kuhn, J.; Langlois, M.; Berdugyna, S.; Tallon, M.

2017-09-01

Telescopes larger than currently planned 30-m class instruments must break the mass-aperture scaling relationship of the Keck-generation of multi-segmented telescopes. Partially filled aperture, but highly redundant baseline interferometric instruments may achieve both large aperture and high dynamic range. The PLANETS FOUNDATION group has explored hybrid telescope-interferometer concepts for narrow-field optical systems that exhibit coronagraphic performance over narrow fields-of-view. This paper describes how the Colossus and Exo-Life Finder telescope designs achieve 10x lower moving masses than current Extremely Large Telescopes.

Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms

ERIC Educational Resources Information Center

Eddy, Sarah L.; Brownell, Sara E.; Wenderoth, Mary Pat

2014-01-01

Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large…

Comparing Novel Multi-Gap Resistive Plate Chamber Models

NASA Astrophysics Data System (ADS)

Stien, Haley; EIC PID Consortium Collaboration

2016-09-01

Investigating nuclear structure has led to the fundamental theory of Quantum Chromodynamics. An Electron Ion Collider (EIC) is a proposed accelerator that would further these investigations. In order to prepare for the EIC, there is an active detector research and development effort. One specific goal is to achieve better particle identification via improved Time of Flight (TOF) detectors. A promising option is the Multi-Gap Resistive Plate Chamber (mRPC). These detectors are similar to the more traditional RPCs, but their active gas gaps have dividers to form several thinner gas gaps. These very thin and accurately defined gas gaps improve the timing resolution of the chamber, so the goal is to build an mRPC with the thinnest gaps to achieve the best possible timing resolution. Two different construction techniques have been employed to make two mRPCs. The first technique is to physically separate the gas gaps with sheets of glass that are .2mm thick. The second technique is to 3D print the layered gas gaps. A comparison of these mRPCs and their performances will be discussed and the latest data presented. This research was supported by US DOE MENP Grant DE-FG02-03ER41243.

The Teaching Gap

ERIC Educational Resources Information Center

Feldman, Sandra

2004-01-01

One of the most comprehensive studies to highlight the achievement gap between students in the United States and those in many other countries is the Third International Mathematics and Science Study (TIMSS). TIMSS showed that a handful of countries (with Japan near the top) consistently outperformed the others studied (including the United…

Polarization-selective optical resonance with extremely narrow linewidth in Si dimers array for application in ultra-sensitive refractive sensing

NASA Astrophysics Data System (ADS)

Fu, Dong; Zhang, Zuyin; Li, Jian; Wu, Haoyue; Wang, Wenbo; Wei, Xin

2017-05-01

By exploiting the radiative coupling between the electromagnetic field scattered by individual Si dimer and the collective wave diffracted (Rayleigh Anomalies) in the plane of Si dimers array, optical resonance with extremely narrow linewidth is achieved, accompanied with dramatic enhancement of electric field in the gap of the dimer. We analyze the optical properties of Si dimers array by decomposing it into three fundamental sub-systems. Theoretical investigation employing the coupled dipole approximation is complemented with numerical simulations. The result shows that polarization angle has significant influence on the orientation of the field scattered by individual Si dimer, which determines the efficiency of radiative coupling and further impacts on the electric field enhancement. Moreover, we explore the feasibility of application in refractive sensing. It is shown that the figure of merit value for the proposed system of Si dimers array is as high as 306. The Si dimers array that takes advantage of multiple coupling creates new possibility to implement field-enhanced spectroscopy and refractive sensing with ultra-high sensitivity.

Gender equality and violent behavior: how neighborhood gender equality influences the gender gap in violence.

PubMed

Lei, Man-Kit; Simons, Ronald L; Simons, Leslie Gordon; Edmond, Mary Bond

2014-01-01

Using a sample of 703 African American adolescents from the Family and Community Health Study (FACHS) along with census data from the year 2000, we examine the association between neighborhood-level gender equality and violence. We find that boys' and girls' violent behavior is unevenly distributed across neighborhood contexts. In particular, gender differences in violent behavior are less pronounced in gender-equalitarian neighborhoods compared to those characterized by gender inequality. We also find that the gender gap narrows in gender-equalitarian neighborhoods because boys' rates of violence decrease whereas girls' rates remain relatively low across neighborhoods. This is in stark contrast to the pessimistic predictions of theorists who argue that the narrowing of the gender gap in equalitarian settings is the result of an increase in girls' violence. In addition, the relationship between neighborhood gender equality and violence is mediated by a specific articulation of masculinity characterized by toughness. Our results provide evidence for the use of gender-specific neighborhood prevention programs.

Gender Equality and Violent Behavior: How Neighborhood Gender Equality Influences the Gender Gap in Violence

PubMed Central

Lei, Man-Kit; Simons, Ronald L.; Simons, Leslie Gordon; Edmond, Mary Bond

2014-01-01

Using a sample of 703 African American adolescents from the Family and Community Health Study (FACHS) along with census data from the year 2000, we examine the association between neighborhood-level gender equality and violence. We find that boys’ and girls’ violent behavior is unevenly distributed across neighborhood contexts. In particular, gender differences in violent behavior are less pronounced in gender-equalitarian neighborhoods compared to those characterized by gender inequality. We also find that the gender gap narrows in gender-equalitarian neighborhoods because boys’ rates of violence decrease whereas girls’ rates remain relatively low across neighborhoods. This is in stark contrast to the pessimistic predictions of theorists who argue that the narrowing of the gender gap in equalitarian settings is the result of an increase in girls’ violence. In addition, the relationship between neighborhood gender equality and violence is mediated by a specific articulation of masculinity characterized by toughness. Our results provide evidence for the use of gender-specific neighborhood prevention programs. PMID:24672996

Structure of Black Male Students Academic Achievement in Science

NASA Astrophysics Data System (ADS)

Rascoe, Barbara

Educational policies and practices have been largely unsuccessful in closing the achievement gap between Black and White students "Schwartz, 2001". This achievement gap is especially problematic for Black students in science "Maton, Hrabrowski, - Schmitt, 2000. Given the fact that the Black-White achievement gap is still an enigma, the purpose of this article is to address the Black female-Black male academic achievement gap in science majors. Addressing barriers that Black male students may experience as college science and engineering majors, this article presents marketing strategies relative to politics, emotional intelligence, and issues with respect to how science teaching, and Black male students' responses to it, are different. Many Black male students may need to experience a paradigm shift, which structures and enhances their science achievement. Paradigm shifts are necessary because exceptional academic ability and motivation are not enough to get Black males from their first year in a science, technology, education, and mathematics "STEM" major to a bachelor's degree in science and engineering. The conclusions focus on the balance of truth-slippery slopes concerning the confluence of science teachers' further ado and Black male students' theories, methods, and values that position their academic achievement in science and engineering majors.

Active linewidth-narrowing of a mid-infrared quantum cascade laser without optical reference.

PubMed

Tombez, L; Schilt, S; Hofstetter, D; Südmeyer, T

2013-12-01

We report on a technique for frequency noise reduction and linewidth-narrowing of a distributed-feedback mid-IR quantum cascade laser (QCL) that does not involve any optical frequency reference. The voltage fluctuations across the QCL are sensed, amplified and fed back to the temperature of the QCL at a fast rate using a near-IR laser illuminating the top of the QCL chip. A locking bandwidth of 300 kHz and a reduction of the frequency noise power spectral density by a factor of 10 with respect to the free-running laser are achieved. From 2 MHz for the free-running QCL, the linewidth is narrowed below 700 kHz (10 ms observation time).

Social Welfare and Minding the Achievement Gap: A View from Denmark

ERIC Educational Resources Information Center

Ringsmose, Charlotte

2012-01-01

In Denmark, the welfare system has evened out the gaps between rich and poor. Schools and child care settings all over the country have an equal level of resources provided by the state, and are financed through taxes. Schools and child care settings in areas with families of lower socioeconomic status (SES) get extra money and resources. All…

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.

Analyzing Bleriot's propeller gaps in Cassini NAC images

NASA Astrophysics Data System (ADS)

Hoffmann, Holger; Chen, Cheng; Seiß, Martin; Albers, Nicole; Spahn, Frank; Nic

2016-10-01

Among the great discoveries of the Cassini mission are the propeller-shaped structures created by small moonlets embedded in Saturn's dense rings. These moonlets are not massive enough to counteract the viscous ring diffusion to open and maintain circumferential gaps, distinguishing them from ring-moons like Pan and Daphnis.Although one of the defining features of propeller structures, well-formed partial gaps have been resolved by the Imaging Science Subsystem Narrow Angle Camera onboard the Cassini spacecraft only for the largest known propeller named Bleriot. We analyze images of the sunlit side of Saturn's outer A ring showing the propeller Bleriot with clearly visible gaps. By fitting a Gaussian to radial brightness profiles at different azimuthal locations, we obtain the evolution of gap minimum and gap width downstream of the moonlet.We report two findings:1) Numerical simulations indicate that the radial separation of the partial propeller gaps is expected to be 4 Hill radii (Spahn and Sremcevic, 2000, A&A). We infer Bleriot's Hill radius to be a few hundred meters, consistent with values given by Sremcevic et al. (2014, DPS) and Hoffmann et al. (2015, Icarus).2) In order to estimate the ring viscosity in the region of Saturn's outer A ring, where Bleriot orbits, we fit several model functions (one example being the analytic solution derived by Sremcevic, Spahn and Duschl, 2002, MNRAS) describing the azimuthal evolution of the surface density in the propeller gap region to the data obtained from the image analysis. We find viscosity values consistent with the parameterization of ring viscosity by Daisaka et al. (2001, Icarus), but significantly lower than the upper limit given by Esposito et al. (1983, Icarus)