South African School Geography:

African Journals Online (AJOL)

Lorraine Innes

Academic Associate, Department of Geography, University of South Africa, ... In conclusion, a case is made for enhancing the status of school Geography by making it a recommended subject for tertiary studies in university programs offering geospatial .... response to the education crisis of the 1970s and 1980s the Human ...

Privatising Public Schooling in Post-Apartheid South Africa: Equity Considerations

Science.gov (United States)

Motala, Shireen

2009-01-01

Through an analysis of quantitative and qualitative data on school funding in South Africa, this paper aims to analyse the user fee policy option in public schooling in South Africa. Debate is ongoing about the role of private input into public schooling and whether this practice affects access (and the constitutional right) to basic education,…

Managing racial integration in South African public schools: In ...

African Journals Online (AJOL)

The paper explores what racial integration is. Furthermore, it scrutinises how racial integration is currently managed in South African Public schools. The main argument of the paper defends a deliberative conception of managing racial integration in South African public schools. In light of this, there is some form of hope to ...

Non-Taylor magnetohydrodynamic self-organization

International Nuclear Information System (INIS)

Zhu, Shao-ping; Horiuchi, Ritoku; Sato, Tetsuya.

1994-10-01

A self-organization process in a plasma with a finite pressure is investigated by means of a three-dimensional magnetohydrodynamic simulation. It is demonstrated that a non-Taylor finite β self-organized state is realized in which a perpendicular component of the electric current is generated and the force-free(parallel) current decreases until they reach to almost the same level. The self-organized state is described by an MHD force-balance relation, namely, j perpendicular = B x ∇p/B·B and j parallel = μB where μ is not a constant, and the pressure structure resembles the structure of the toroidal magnetic field intensity. Unless an anomalous perpendicular thermal conduction arises, the plasma cannot relax to a Taylor state but to a non-Taylor (non-force-free) self-organized state. This state becomes more prominent for a weaker resistivity condition. The non-Taylor state has a rather universal property, for example, independence of the initial β value. Another remarkable finding is that the Taylor's conjecture of helicity conservation is, in a strict sense, not valid. The helicity dissipation occurs and its rate slows down critically in accordance with the stepwise relaxation of the magnetic energy. It is confirmed that the driven magnetic reconnection caused by the nonlinearly excited plasma kink flows plays the leading role in all of these key features of the non-Taylor self-organization. (author)

Challenges Facing Managers in Managing Conflict in Schools in the South and South Central Regions of Botswana

Science.gov (United States)

Morake, Nnior Machomi; Monobe, Ratau John; Dingwe, Stephonia

2011-01-01

The purpose of this study was to examine the challenges facing managers in managing conflict in schools of South and South Central Regions of Botswana. In this study, the schedule of interview was used to collect empirical data. A random sample of 50 school managers and deputy school managers was selected for interviews. Major findings of the…

Taylor instability in rhyolite lava flows

Science.gov (United States)

Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

1989-01-01

A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

Making Schools Safer in South Africa: An Antihomophobic Bullying Educational Resource

Science.gov (United States)

Reygan, Finn

2016-01-01

The limited research indicates that homophobia is widespread in South African schools and that schools are ill-prepared to challenge homophobic bullying. In this context, using Kumashiro's antioppressive educational framework, the author outlines the process of developing an antihomophobic educational resource for use in South African schools, its…

School Expenditure and School Performance: Evidence from New South Wales Schools Using a Dynamic Panel Analysis

Science.gov (United States)

Pugh, G.; Mangan, J.; Blackburn, V.; Radicic, D.

2015-01-01

This article estimates the effects of school expenditure on school performance in government secondary schools in New South Wales, Australia over the period 2006-2010. It uses dynamic panel analysis to exploit time series data on individual schools that only recently has become available. We find a significant but small effect of expenditure on…

School Governing Bodies in South African Schools: Under Pressure to Enhance Democratization and Improve Quality

Science.gov (United States)

Heystek, Jan

2011-01-01

Governing bodies in South Africa are expected to have an important role in ensuring high quality education in schools as well as in the democratization of the post-apartheid South Africa. However, current legislation precludes governing bodies from involvement in the professional management of schools. Governing bodies are democratically elected…

Rayleigh-Taylor mixing in supernova experiments

International Nuclear Information System (INIS)

Swisher, N. C.; Abarzhi, S. I.; Kuranz, C. C.; Arnett, D.; Hurricane, O.; Remington, B. A.; Robey, H. F.

2015-01-01

We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study core-collapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blast-wave with helium-hydrogen interface, and the induced Rayleigh-Taylor instability and Rayleigh-Taylor mixing of the denser and lighter fluids with time-dependent acceleration. We analyze all available experimental images of the Rayleigh-Taylor flow in supernova experiments and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By properly accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are reported to describe asymptotic dynamics of Rayleigh-Taylor flow with time-dependent acceleration by applying theoretical analysis that considers symmetries and momentum transport. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments Rayleigh-Taylor flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; Rayleigh-Taylor mixing keeps order

School Choice and Educational Inequality in South Korea

Science.gov (United States)

Byun, Soo-Yong; Kim, Kyung-Keun; Park, Hyunjoon

2012-01-01

Using a nationally representative sample of eleventh grade students in South Korea, we investigated how the residentially based school assignment policy called the High School Equalization Policy (HSEP) shaped the separation of low and high socioeconomic status (SES) students between schools. We found that there was a smaller between-school…

The Mantle and Basalt-Crust Interaction Below the Mount Taylor Volcanic Field, New Mexico

Science.gov (United States)

Schrader, Christian M.; Crumpler, Larry S.; Schmidt, Marick E.

2010-01-01

The Mount Taylor Volcanic Field (MTVF) lies on the Jemez Lineament on the southeastern margin of the Colorado Plateau. The field is centered on the Mt. Taylor composite volcano and includes Mesa Chivato to the NE and Grants Ridge to the WSW. MTVF magmatism spans approximately 3.8-1.5 Ma (K-Ar). Magmas are dominantly alkaline with mafic compositions ranging from basanite to hy-basalt and felsic compositions ranging from ne-trachyte to rhyolite. We are investigating the state of the mantle and the spatial and temporal variation in basalt-crustal interaction below the MTVF by examining mantle xenoliths and basalts in the context of new mapping and future Ar-Ar dating. The earliest dated magmatism in the field is a basanite flow south of Mt. Taylor. Mantle xenolith-bearing alkali basalts and basanites occur on Mesa Chivato and in the region of Mt. Taylor, though most basalts are peripheral to the main cone. Xenolith-bearing magmatism persists at least into the early stages of conebuilding. Preliminary examination of the mantle xenolith suite suggests it is dominantly lherzolitic but contains likely examples of both melt-depleted (harzburgitic) and melt-enriched (clinopyroxenitic) mantle. There are aphyric and crystal-poor hawaiites, some of which are hy-normative, on and near Mt. Taylor, but many of the more evolved MTVF basalts show evidence of complex histories. Mt. Taylor basalts higher in the cone-building sequence contain >40% zoned plagioclase pheno- and megacrysts. Other basalts peripheral to Mt. Taylor and at Grants Ridge contain clinopyroxene and plagioclase megacrysts and cumulate-textured xenoliths, suggesting they interacted with lower crustal cumulates. Among the questions we are addressing: What was the chemical and thermal state of the mantle recorded by the basaltic suites and xenoliths and how did it change with time? Are multiple parental basalts (Si-saturated vs. undersaturated) represented and, if so, what changes in the mantle or in the tectonic

Budget Monitoring and Control in South African Township Schools: Democratic Governance at Risk

Science.gov (United States)

Mestry, Raj; Naidoo, Gans

2009-01-01

This article investigates budget monitoring and control in township schools in South Africa. The enactment of the Schools Act 1996 revolutionized school financial management in South Africa, making it part of the drive for democratic school governance. School governing bodies had to be established, whose responsibility it became to manage finances…

School Expansion in North Korea and South Korea: Two Systems, Two Approaches.

Science.gov (United States)

Lee, Hyangkue

2001-01-01

Examines differences in the public-policy objectives and financing of school expansion efforts in North and South Korea. Institutionalizing credentialism and reliance on financing private education dominates South Korean school expansion, while the financing of public schools and greater government control of education dominates North Korean…

Academic Differentiation, School Achievement and School Violence in the USA and South Korea

Science.gov (United States)

Akiba, Motoko; Han, Seunghee

2007-01-01

Whilst school violence is a major public concern and a focus of educational reforms both in the USA and South Korea, few studies have comparatively examined the rates of school violence and school factors associated with them. Analysing nationally-representative data from eighth graders, their mathematics teachers and principals in 150 South…

33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation lock...

The Nature, Causes and Effects of School Violence in South African High Schools

Science.gov (United States)

Ncontsa, Vusumzi Nelson; Shumba, Almon

2013-01-01

We sought to investigate the nature, causes and effects of school violence in four South African high schools. A purposive sample of five principals, 80 learners and 20 educators was selected from the four schools used in the study. A sequential mixed method approach was used in this study; both questionnaires and interviews were used. The design…

Politics and the Practice of School Change: The Hyukshin School Movement in South Korea

Science.gov (United States)

Sung, Youl-Kwan; Lee, Yoonmi

2018-01-01

In this article, we examine the characteristics of a progressive school-change project in South Korea called the "Hyukshin" School (HS) movement. HSs are public schools that are intended to disseminate progressive and democratic practices. We obtained data from interviews with participating teachers, official documents, reports, and…

Circulation, retention, and mixing of waters within the Weddell-Scotia Confluence, Southern Ocean: The role of stratified Taylor columns

Science.gov (United States)

Meredith, Michael P.; Meijers, Andrew S.; Naveira Garabato, Alberto C.; Brown, Peter J.; Venables, Hugh J.; Abrahamsen, E. Povl; Jullion, Loïc.; Messias, Marie-José

2015-01-01

The waters of the Weddell-Scotia Confluence (WSC) lie above the rugged topography of the South Scotia Ridge in the Southern Ocean. Meridional exchanges across the WSC transfer water and tracers between the Antarctic Circumpolar Current (ACC) to the north and the subpolar Weddell Gyre to the south. Here, we examine the role of topographic interactions in mediating these exchanges, and in modifying the waters transferred. A case study is presented using data from a free-drifting, intermediate-depth float, which circulated anticyclonically over Discovery Bank on the South Scotia Ridge for close to 4 years. Dimensional analysis indicates that the local conditions are conducive to the formation of Taylor columns. Contemporaneous ship-derived transient tracer data enable estimation of the rate of isopycnal mixing associated with this column, with values of O(1000 m2/s) obtained. Although necessarily coarse, this is of the same order as the rate of isopycnal mixing induced by transient mesoscale eddies within the ACC. A picture emerges of the Taylor column acting as a slow, steady blender, retaining the waters in the vicinity of the WSC for lengthy periods during which they can be subject to significant modification. A full regional float data set, bathymetric data, and a Southern Ocean state estimate are used to identify other potential sites for Taylor column formation. We find that they are likely to be sufficiently widespread to exert a significant influence on water mass modification and meridional fluxes across the southern edge of the ACC in this sector of the Southern Ocean.

Beyond Passivity: Constructions of Femininities in a Single-Sex South African School

Science.gov (United States)

Bhana, Deevia; Pillay, Nalini

2011-01-01

In the context of the calamitous effects of gender violence on the experience of schooling for South African girls, single-sex schools have been advanced as a strategy to protect girls from violence. In this paper, the experiences of a selected group of girls in a single-sex school in Durban, South Africa are illustrated to provide a counter…

Towards environment and health promoting South African schools.

Science.gov (United States)

Mathee, A; Byrne, J

1996-03-01

This article describes the activities of the Greater Johannesburg Healthy Schools Program of the World Health Organization's (WHO) Healthy Cities Project in South Africa. Healthy Cities projects emphasize community participation, intersectoral action, supportive environments for health, and a settings approach. Children in South Africa, are exposed to environmental and health hazards in the school setting including poor building design, poor equipment, and understaffing. The Healthy Schools initiative in Greater Johannesburg, is a pilot for enhancing environmental quality, health, and well-being among students. Schools include those in an informal settlement in an industrial area, an inner city district, and in a suburban area. The initiative includes research, establishment of environmental and health committees, development of an action plan, and evaluation and feedback. The plan aims to promote environmental and health sustainability, to empower children to become full participants in the community, and to support teachers and parents in the promotion of health-enhancing school environments. The program builds upon the lessons learned from several local school initiatives. Initiatives include an anti-smoking poster competition involving over 10,000 students, special environmental and health awareness days, consciousness raising among high school students about air pollution, and local efforts to engage students in environmental clean-up days.

76 FR 76689 - Cibola National Forest, Mount Taylor Ranger District, NM, Mount Taylor Combined Exploratory Drilling

Science.gov (United States)

2011-12-08

... National Forest, Mount Taylor Ranger District, NM, Mount Taylor Combined Exploratory Drilling AGENCY... proposed action is to approve two Plans of Operations for exploratory uranium drilling on the Cibola... San Mateo. In total, there are up to 279 drill holes that would be drilled over a period not to exceed...

"No Fee" Schools in South Africa. Policy Brief Number 7

Science.gov (United States)

Motala, Shireen; Sayeed, Yusuf

2009-01-01

40% of schools in South Africa, namely the poorest two-fifths as determined by poverty indicators, were declared to be no fee schools as of 2007. These schools receive larger state allocations per learner than other schools, as well as a higher allocation for non-personnel, non-capital expenditure. In other schools parents may continue to apply…

Challenges facing eTextbook provision to South African schools

CSIR Research Space (South Africa)

Dlodlo, N

2012-10-01

Full Text Available international companies are very expensive for the South African environment, and this would result in uneven access to such resources. Therefore South Africa has to come up with its own low-cost appropriate technologies to enable eBook provision to the schools...

Guidelines for the marketing of independent schools in South Africa

Directory of Open Access Journals (Sweden)

Reaan Immelman

2015-02-01

Full Text Available Objective: The primary objective of the study is to recommend marketing guidelines for independent primary schools, with the focus on product and people in the marketing mix. This objective was achieved by identifying choice factors influencing parents’ selection of independent primary schools, identifying the most important choice factors and demographic differences regarding the importance parents attached to these factors. Problem investigated: Some independent schools in South Africa find it difficult to market themselves effectively as a result of a lack of information pertaining to the choice factors identified by parents when selecting independent primary schools. A comprehensive set of choice factors will provide a more accurate picture of the criteria parents perceive as important in independent school selection. Methodology: The methodological approach followed was exploratory and quantitative in nature. The sample consisted of 669 respondents from 30 independent schools in Gauteng in South Africa. A structured questionnaire, with a five-point Likert scale, was fielded to gather the data. The descriptive and factor analysis approaches were used to analyse the results. Findings and implications: The main finding is that a total of 29 different choice factors were identified that parents perceive as important when selecting an independent primary school. The most important factor for parents when making a choice is the small size of the classes, followed by the religious ethos of the school as well as qualified and committed educators. This indicates that parents have a comprehensive set of choice factors and implies that a better understanding of these factors by independent schools may assist them to focus their marketing efforts more optimally in order to attract new learners. Originality and value of the research: Very little research exists with specific reference to independent school marketing in South Africa

33 CFR 117.987 - Taylor Bayou.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union Pacific...

O salário na obra de Frederick Winslow Taylor Frederick Winslow Taylor's oeuvre: an analysis of wages

Directory of Open Access Journals (Sweden)

Victor Paulo Gomes da Silva

2011-08-01

Full Text Available O presente artigo analisa e explica a perspectiva de Frederick Winslow Taylor sobre o salário, tal como enunciada em suas duas grandes obras: Shop management (1903 e Principles of scientific management (1911. A primeira parte consubstancia-se na apresentação de aspectos econômicos relevantes que caracterizaram o tempo em que ele viveu e o quanto influenciaram suas obras. Na segunda parte, é efetuada uma análise da forma como o salário é apresentado nas duas obras de F. W. Taylor. O artigo termina com um comentário sobre as obras supracitadas no que se refere à perspectiva taylorista do salário.This paper analyses and explains Frederick Winslow Taylor's perspective on wages, as it is presented in his main literary works: Shop management (1903 and Principles of scientific management (1911. The first part presents the main economic aspects that characterized his lifetime, which undoubtedly influenced his literary works. The second part analyses F. W. Taylor's two main books in which the author's perspective about wages is discussed. The paper concludes with a critical view of F. W. Taylor's view on wages.

Characteristics of astigmatism in Black South African high school ...

African Journals Online (AJOL)

Keywords: Astigmatism prevalence, school children, South Africa. ... ception and symptoms.3 The high school population is of interest given that they ..... Malaysia. Asian. 7-15. 4634. ≤−0.75 15.7. Paudel te al45. Vietnam. Asian. 12-15. 2238.

33 CFR 117.335 - Taylor Creek.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile 0...

Evaluation of a school-based intervention programme for South ...

African Journals Online (AJOL)

Objective: Parental divorce affects approximately 30 000 South African children annually. This pilot study aimed to evaluate the effectiveness of the Children of Divorce Intervention Programme (CODIP) at two South African schools. CODIP is a preventively oriented group programme which was developed to foster resilience ...

A spherical Taylor-Couette dynamo

Science.gov (United States)

Marcotte, Florence; Gissinger, Christophe

2016-04-01

We present a new scenario for magnetic field amplification in the planetary interiors where an electrically conducting fluid is confined in a differentially rotating, spherical shell (spherical Couette flow) with thin aspect-ratio. When the angular momentum sufficiently decreases outwards, a primary hydrodynamic instability is widely known to develop in the equatorial region, characterized by pairs of counter-rotating, axisymmetric toroidal vortices (Taylor vortices) similar to those observed in cylindrical Couette flow. We characterize the subcritical dynamo bifurcation due to this spherical Taylor-Couette flow and study its evolution as the flow successively breaks into wavy and turbulent Taylor vortices for increasing Reynolds number. We show that the critical magnetic Reynolds number seems to reach a constant value as the Reynolds number is gradually increased. The role of global rotation on the dynamo threshold and the implications for planetary interiors are finally discussed.

[South Carolina School-to-Work Brochures.

Science.gov (United States)

Partnership for Academic and Career Education, Pendleton, SC.

This packet includes three pamphlets from the South Carolina School-to-Work Initiative, which involves many components in ensuring for students high levels of academic and technical achievement; strong problem-solving, teamwork and technology skills; clear career goals; better access to postsecondary education and meaningful employment; and a…

Safety Valve or Sinkhole? Vocational Schooling in South Africa

OpenAIRE

Pugatch, Todd

2012-01-01

As an alternative to traditional academic schooling, vocational schooling in South Africa may serve as a safety valve for students encountering difficulty in the transition from school to work. Yet if ineffective, vocational schooling could also be a sinkhole, offering little chance for success on the labor market. After defining the terms "safety valve" and "sinkhole" in a model of human capital investment with multiple schooling types, I test for evidence of these characteristics using a pa...

American Philanthropic Studies: The Chicago School of Civics and Philanthropy (1903-1920)

Science.gov (United States)

Seely, Dagmar

2014-01-01

Graham Taylor was a leader in the movement for schools of civics and philanthropy. As founder of the Chicago School of Civics and Philanthropy, Taylor served as President and Professor. The study focuses on the development of the study of philanthropy through following the pedagogy of Graham Taylor beginning with his early efforts during the late…

School tuck shops in South Africa—an ethical appraisal

African Journals Online (AJOL)

a formal tuck shop, at other schools, food vendors sell food either on or outside the school premises. ... Overweight and obesity, with a prevalence of 36.9% in men and ..... their association with BMI Z-score and fat mass in South African.

Race-ing Class Ladies: Lineages of Privilege in an Elite South African School

Science.gov (United States)

Epstein, Debbie

2014-01-01

This paper draws on fieldwork done in Greystone School in South Africa, a single sex girls' school. I explore how the legacy of coloniser and colonised is reconfigured through the history of the school and the particular racialised politics of South Africa, where race and class have always been imbricated in differently nuanced ways before, during…

Interaction between ground water and surface water in Taylor Slough and vicinity, Everglades National Park, South Florida; study methods and appendixes

Science.gov (United States)

Harvey, Judson W.; Jackson, J.M.; Mooney, R.H.; Choi, Jungyill

2000-01-01

The data presented in this report are products of an investigation that quantified interactions between ground water and surface water in Taylor Slough in Everglades National Park. Determining the extent of hydrologic interactions between wetland surface water and ground water in Taylor Slough is important because the balance of freshwater flow in the lower part of the Slough is uncertain. Although freshwater flows through Taylor Slough are quite small in comparison to Shark Slough (the larger of the two major sloughs in Everglades National Park), flows through Taylor Slough are especially important to the ecology of estuarine mangrove embayments of northeastern Florida Bay. Also, wetland and ground- water interactions must be quantified if their role in affecting water quality is to be determined. In order to define basic hydrologic characteristics of the wetland, depth of wetland peat was mapped, and hydraulic conductivity and vertical hydraulic gradients in peat were determined. During specific time periods representing both wet and dry conditions in the area, the distribution of major ions, nutrients, and water stable isotopes throughout the slough were determined. The purpose of chemical measurements was to identify an environmental tracer could be used to quantify ground-water discharge.

The Role of Democratic Governing Bodies in South African Schools.

Science.gov (United States)

Karlsson, Jenni

2002-01-01

School governance reform in post-apartheid South Africa aimed to democratize schooling while accommodating diverse school histories of underdevelopment or self-management. Analysis of relevant legislation shows the reform was structured to allow representative democracy and partnerships. But two recent studies suggest that governance reforms have…

String-theoretic deformation of the Parke-Taylor factor

Science.gov (United States)

Mizera, Sebastian; Zhang, Guojun

2017-09-01

Scattering amplitudes in a range of quantum field theories can be computed using the Cachazo-He-Yuan (CHY) formalism. In theories with color ordering, the key ingredient is the so-called Parke-Taylor factor. In this paper we give a fully SL (2 ,C )-covariant definition and study the properties of a new integrand called the "string Parke-Taylor" factor. It has an α' expansion whose leading coefficient is the field-theoretic Parke-Taylor factor. Its main application is that it leads to a CHY formulation of open string tree-level amplitudes. In fact, the definition of the string Parke-Taylor factor was motivated by trying to extend the compact formula for the first α' correction found by He and Zhang, while the main ingredient in its definition is a determinant of a matrix introduced in the context of string theory by Stieberger and Taylor.

Causes of financial mismanagement in South African public schools ...

African Journals Online (AJOL)

PAUL

2016-08-12

Aug 12, 2016 ... Joubert and Van Rooyen (2008) state that many schools in South Africa ... problems of mismanagement, managerial incompetence, lack of ... hampered by a global tendency of financial mismanagement, which is .... ment of Education Institutional Governance Foren- ..... corruption-in-schools-on-the-rise/.

Non-vanishing of Taylor coefficients and Poincaré series

DEFF Research Database (Denmark)

O'Sullivan, C.; Risager, Morten S.

2013-01-01

We prove recursive formulas for the Taylor coefficients of cusp forms, such as Ramanujan's Delta function, at points in the upper half-plane. This allows us to show the non-vanishing of all Taylor coefficients of Delta at CM points of small discriminant as well as the non-vanishing of certain...... Poincaré series. At a "generic" point, all Taylor coefficients are shown to be non-zero. Some conjectures on the Taylor coefficients of Delta at CM points are stated....

Special Theory of Relativity in South Korean High School Textbooks and New Teaching Guidelines

Science.gov (United States)

Gim, Jinyeong

2016-01-01

South Korean high school students are being taught Einstein's Special Theory of Relativity. In this article, I examine the portrayal of this theory in South Korean high school physics textbooks and discuss an alternative method used to solve the analyzed problems. This examination of how these South Korean textbooks present this theory has…

Taylor series maps and their domain of convergence

International Nuclear Information System (INIS)

Abell, D.T.; Dragt, A.J.

1992-01-01

This paper tries to make clear what limits the validity of a Taylor series map, and how. We describe the concept of a transfer map and quote some theorems that justify not only their existence but also their advantages. Then, we describe the Taylor series representation for transfer maps. Following that, we attempt to elucidate some of the basic theorems from the theory of functions of one and several complex variables. This material forms the core of our understanding of what limits the domain of convergence of Taylor series maps. Lastly, we use the concrete example of a simple anharmonic oscillator to illustrate how the theorems from several complex variable theory affect the domain convergence of Taylor series maps. There we describe the singularities of the anharmonic oscillator in the complex planes of the initial conditions, show how they constrain our use of a Taylor series map, and then discuss our findings

Taylorism and the Logic of Learning Outcomes

Science.gov (United States)

Stoller, Aaron

2015-01-01

This essay examines the shared philosophical foundations of Fredrick W. Taylor's scientific management principles and the contemporary learning outcomes movement (LOM). It analyses the shared philosophical ground between the focal point of Taylor's system--"the task"--and the conceptualization and deployment of "learning…

The Life and Legacy of G. I. Taylor

Science.gov (United States)

Batchelor, G. K.

1996-07-01

G.I. Taylor, one of the most distinguished physical scientists of this century, used his deep insight and originality to increase our understanding of phenomena such as the turbulent flow of fluids. His interest in the science of fluid flow was not confined to theory; he was one of the early pioneers of aeronautics, and designed a new type of anchor that was inspired by his passion for sailing. Taylor spent most of his working life in the Cavendish Laboratory in Cambridge, where he investigated the mechanics of fluid and solid materials; his discoveries and ideas have had application throughout mechanical, civil, and chemical engineering, meteorology, oceanography and materials science. He was also a noted research leader, and his group in Cambridge became one of the most productive centers for the study of fluid mechanics. How was Taylor able to be innovative in so many different ways? This interesting and unusual biography helps answer that question. Professor Batchelor, himself a student and close collaborator of Taylor, is ideally placed to describe Taylor's life, achievements and background. He does so without introducing any mathematical details, making this book enjoyable reading for a wide range of people--and especially those whose own interests have brought them into contact with the legacy of Taylor.

Cyberbullying in South African and American schools: A legal ...

African Journals Online (AJOL)

Hennie

stressed (Burton & Mutongwizo, 2009); the educational institution should ... especially in South Africa, where this has claimed the lives of both learners and ... Studies on violence in the workplace and on bullying in ... tives, and to balance the rights of the various parties in a school environment. ...... School social workers'.

Educar na autenticidade em Charles Taylor = Educating in the authenticity in Charles Taylor

Directory of Open Access Journals (Sweden)

Foschiera, Rogério

2009-01-01

Full Text Available Analiso a perspectiva tayloriana da autencidade através de uma hermenêutica de suas principais obras para propor o significado de educar na autencticidade a partir de Charles Taylor. Com autencidade e ontologia moral Taylor apresenta uma antropologia ancorada na moral e na ontologia. Com autencidade e epistemologia se percebe que a perspectiva da autencidade não exclui o paradigma científico, mas necessita de outros paradigmas, principalmente do hermenêutico. Com autencidade e linguagem evidencio a compreensão de Taylor sobre a natureza da linguagem e o destaque que ele dá á definição de ser humano como "animal portador de logos", bem como o significado e as decorrências da perspectiva expressivista. Duas políticas: a da igualdade de direitos de todos e a do reconhecimento das diferenças estão integradas na perspectiva tayloriana da autencidade. Necessariamente, o ser humano, para ser autêntico, estará em constante referência a horizontes de sentido que transcendem o indivíduo, é o que apresento com autencidade e transcendência

Reconsidering the role of power, punishment and discipline in South African schools

Directory of Open Access Journals (Sweden)

E. Venter

2011-06-01

Full Text Available This article examines the role of discipline and punishment in South African schools and seeks to interrogate the underlying power relations that guide teaching and learning in South Africa. It deconstructs the pre-occupation with discipline, power and punishment in South African schools in terms of the theoretical framework provided by Michel Foucault in his work entitled “Surveiller et punir: naissance de la prison” (1975 which was translated as “Discipline and punish: the birth of the prison”(1977. It was Foucault who reminded us that the modern school is based on Prussian military ideals of punctuality, discipline, neatness and submissiveness to authority. Foucault tends to see schooling as one side of “corriger”, which is to punish or to teach. Education as “correction” is therefore regarded as the antipode of authoritarian punishment. Foucault draws attention to the subtle tactics and constraints beneath the surface of proclaimed bourgeois freedom. It was found that in South African schools the problem of authoritarian punishment is still rife. From the readings of Foucault’s works suggestions are made for changes to the system and to teachers’ mental attitude in order to move to a more constructive way of maintaining power and discipline.

Homophobia and Sexuality Diversity in South African Schools: A Review

Science.gov (United States)

Francis, Dennis A.

2017-01-01

Post-apartheid, there has been an increase in research on issues of gender and sexuality diversity in South African schools. To build upon and advance gender and sexuality diversity studies, I conducted a review of the literature that addresses how lesbian, gay, bisexual, and transgender (LGBT) youth experience schooling and how schools, if at…

Mental skills of South African male high school rugby players ...

African Journals Online (AJOL)

The aim of this study was to establish preliminary South African high school rugby norms for the BMSQ. The sample consisted of 152 male high school rugby players from two schools in the Ethekwini region. Preliminary norms are presented in the form of means and standard deviations. Results are compared with those of ...

On truncated Taylor series and the position of their spurious zeros

DEFF Research Database (Denmark)

Christiansen, Søren; Madsen, Per A.

2006-01-01

A truncated Taylor series, or a Taylor polynomial, which may appear when treating the motion of gravity water waves, is obtained by truncating an infinite Taylor series for a complex, analytical function. For such a polynomial the position of the complex zeros is considered in case the Taylor...

Taylor's series method for solving the nonlinear point kinetics equations

International Nuclear Information System (INIS)

Nahla, Abdallah A.

2011-01-01

Highlights: → Taylor's series method for nonlinear point kinetics equations is applied. → The general order of derivatives are derived for this system. → Stability of Taylor's series method is studied. → Taylor's series method is A-stable for negative reactivity. → Taylor's series method is an accurate computational technique. - Abstract: Taylor's series method for solving the point reactor kinetics equations with multi-group of delayed neutrons in the presence of Newtonian temperature feedback reactivity is applied and programmed by FORTRAN. This system is the couples of the stiff nonlinear ordinary differential equations. This numerical method is based on the different order derivatives of the neutron density, the precursor concentrations of i-group of delayed neutrons and the reactivity. The r th order of derivatives are derived. The stability of Taylor's series method is discussed. Three sets of applications: step, ramp and temperature feedback reactivities are computed. Taylor's series method is an accurate computational technique and stable for negative step, negative ramp and temperature feedback reactivities. This method is useful than the traditional methods for solving the nonlinear point kinetics equations.

Management of School Infrastructure in the Context of a No-Fee Schools Policy in Rural South African Schools: Lessons from the Field

Science.gov (United States)

Marishane, Ramodikoe Nylon

2013-01-01

This study examines the management of school infrastructure in the context of the "no-fee schools" policy introduced in the South African education delivery system. Focusing on four rural schools, the study applied a qualitative method, which involved observation of infrastructure conditions prevailing at four selected schools and…

76 FR 3570 - Proposed Amendment of Class E Airspace; Taylor, AZ

Science.gov (United States)

2011-01-20

...-1189; Airspace Docket No. 10-AWP-19] Proposed Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal... proposes to modify Class E airspace at Taylor Airport, Taylor, AZ. Controlled airspace is necessary to accommodate aircraft using the CAMBO One Departure Area Navigation (RNAV) out of Taylor Airport. The FAA is...

Globalisation and governance | Taylor | New Agenda: South African ...

African Journals Online (AJOL)

New Agenda: South African Journal of Social and Economic Policy. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 37 (2010) >. Log in or Register to get access to full text downloads.

Blocking the Bullies: Has South Carolina's Safe School Climate Act Made Public Schools Safer?

Science.gov (United States)

Terry, Troy M.

2010-01-01

Recent news in the national media about two students' deaths as a result of harassment in school has highlighted a renewed desire for educators to address the culture of bullying and harassment in public schools, especially when the victims are targeted for their real or perceived differences. South Carolina's legislature responded to this need in…

Performing privacy in schools

DEFF Research Database (Denmark)

Lauritsen, Peter; Bøge, Ask Risom; Andersen, Lars Bo

with technologies is carried out as well as observation is conducted. We obtain and present new knowledge about how surveillance is practiced in the interpersonal relations of students and teachers. References: Monahan, T., & Torres, R. D. (2009). Schools Under Surveillance: Cultures of Control in Public Education....... Rutgers University Press. Selwyn, N. (2010). Schools and Schooling in the Digital Age: A Critical Analysis. Routledge. Taylor, E. (2013). Surveillance Schools: Security, Discipline and Control in Contemporary Education. Palgrave Macmillan UK. Taylor, E., & Rooney, T. (2016). Surveillance Futures: Social......In this presentation we pursue the question: How is privacy performed and perceived in schools by children? Our aim is to investigate how the boundaries between public and private spheres are continuously performed in the formal setting of the classroom as well as in the social lives of students...

Stressors in the professional lives of South African secondary school ...

African Journals Online (AJOL)

We identify current stressors in the professional lives of South African secondary school educators. The study was exploratory, using a questionnaire, which listed 19 possible causes of stress and was completed by 987 educators from all racial groups and provinces in the country. South African educators in general ...

Application of Taylor-Series Integration to Reentry Problems with Wind

NARCIS (Netherlands)

Bergsma, Michiel; Mooij, E.

2016-01-01

Taylor-series integration is a numerical integration technique that computes the Taylor series of state variables using recurrence relations and uses this series to propagate the state in time. A Taylor-series integration reentry integrator is developed and compared with the fifth-order

The Legislative Framework Regarding Bullying In South African Schools

Directory of Open Access Journals (Sweden)

Annelie Laas

2014-12-01

Full Text Available Bullying in schools is a global phenomenon that has the potential to impact on children not only physically but also psychologically. In South Africa countless children fall victim to bullying, harassment and abuse at schools. A myriad of constitutional rights are infringed upon when bullying occurs, and the problem is escalating. The Protection from Harassment Act 71 of 2011 was signed and accepted into law on the 27th of April 2013. This new Act may grant relief to victims of bullying inter alia by providing for protection orders, and therefore adds to the legislative framework available to victims. However, in terms of bullying in schools, the parties to these incidents are minors and therefore a critical analysis is necessary with regard to the rights of the victim and the offender. In this context the relationship and interaction between the Protection from Harassment Act 71 of 2011, the Child Justice Act 75 of 2008, the Children's Act 38 of 2005 and the South African Schools Act 84 of 1996 call for critical analysis.

Generalization of the Taylor Principle

International Nuclear Information System (INIS)

Jensen, T.H.

1986-01-01

The usual Taylor Principle can in general only be applied when the system is closed. This paper describes a suggestion of a generalization to cover the case that the plasma is surrounded by a conducting shell with narrow gaps where the external circuits connected to the gaps consist of just inductors. The suggested constraint of the generalized Taylor Principle is that no helicity is absorbed by the plasma. The usual assumption that the stable Taylor Equilibrium is that for which the magnetic energy in the plasma region as well as in the external inductors is minimized subject to the above constraint, again leads to a unique configuration. It is found that this configuration is dependent upon the inductances of the external inductors. For the sake of conceptual simplicity, consider a closed shell of conducting material. The interior of the shell may be divided into various compartments only corrected through narrow gaps in the conducting walls between these compartments. They assume plasma present in only one of the compartments; the neighboring compartments represent the external inductors connected across the gaps of the plasma compartment

The New Taylorism: Hacking at the Philosophy of the University's End

Science.gov (United States)

Goodman, Robin Truth

2012-01-01

This article looks at the critical writings of Mark C. Taylor. It suggests that Mark C. Taylor is rewriting a global imaginary devoid of the kind of citizenship that Henry Giroux claims as the basis for public education. Instead, Taylor wants to see the university take shape as profit-generating. According to Taylor, in lieu of learning to take…

School Choice and Inequalities in Post-Apartheid South Africa

Science.gov (United States)

Ndimande, Bekisizwe S.

2016-01-01

This paper examines the consequences of the new policies of school choice in post-apartheid South Africa and the reasons they have largely failed to achieve greater educational equality--their stated purpose. I argue that the dominant reason for this lies in the continuing inadequate resources of many poor schools and the failure to address them.…

Adolescent alcohol use in rural South African high schools | Onya ...

African Journals Online (AJOL)

Objective: To examine psychosocial correlates of lifetime alcohol use among adolescents in rural South African high schools. Method: Questionnaires were administered to 1600 students from 20 randomly selected high schools in the Mankweng district within Limpopo province. Self-report data on alcohol use, demographic, ...

Short-term initiatives for enhancing cyber-safety within South African schools

Directory of Open Access Journals (Sweden)

Elmarie Kritzinger

2016-07-01

Full Text Available The rate of technological development across the globe is dramatic. The decreasing cost and increasing availability of ICT devices means that its users are no longer exclusively industry or government employees – they are now also home users. Home users integrate ICT in their daily lives for education, socialising and information gathering. However, using ICT is associated with risks and threats, such as identity theft and phishing scams. Most home users of ICT do not have the necessary information technology and Internet skills to protect themselves and their information. School learners, in particular, are not sufficiently educated on how to use technological devices safely, especially in developing countries such as South Africa. The national school curriculum in South Africa currently does not make provision for cyber-safety education, and the availability of supporting material and training for ICT teachers in South Africa is limited, resulting in a lack of knowledge and skills regarding cyber-safety. The research in hand focuses on the situation concerning cyber-safety awareness in schools and has adopted a short-term approach towards cyber-safety among teachers and school learners in South Africa until a formal long-term national approach has been implemented. This study takes a quantitative approach to investigating the current options of teachers to enhance cyber-safety among learners in their schools. The research proposes that short-term initiatives (i.e. posters can increase learners’ awareness of cyber-safety until formal cyber-safety awareness methods have been introduced.

Dynamic Transition and Pattern Formation in Taylor Problem

Institute of Scientific and Technical Information of China (English)

Tian MA; Shouhong WANG

2010-01-01

The main objective of this article is to study both dynamic and structural transitions of the Taylor-Couette flow,by using the dynamic transition theory and geometric theory of incompressible flows developed recently by the authors.In particular,it is shown that as the Taylor number crosses the critical number,the system undergoes either a continuous or a jump dynamic transition,dictated by the sign of a computable,nondimensional parameter R.In addition,it is also shown that the new transition states have the Taylor vortex type of flow structure,which is structurally stable.

76 FR 18378 - Amendment of Class E Airspace; Taylor, AZ

Science.gov (United States)

2011-04-04

...-1189; Airspace Docket No. 10-AWP-19] Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action will amend Class E airspace at Taylor Airport, Taylor, AZ, to accommodate aircraft using the CAMBO One Departure, and the Area Navigation (RNAV...

Fluid Mechanics of Taylor Bubbles and Slug Flows in Vertical Channels

International Nuclear Information System (INIS)

Anglart, Henryk; Podowski, Michael Z.

2002-01-01

Fluid mechanics of Taylor bubbles and slug flows is investigated in vertical, circular channels using detailed, three-dimensional computational fluid dynamics simulations. The Volume of Fluid model with the interface-sharpening algorithm, implemented in the commercial CFX4 code, is used to predict the shape and velocity of Taylor bubbles moving along a vertical channel. Several cases are investigated, including both a single Taylor bubble and a train of bubbles rising in water. It is shown that the potential flow solution underpredicts the water film thickness around Taylor bubbles. Furthermore, the computer simulations that are performed reveal the importance of properly modeling the three-dimensional nature of phenomena governing the motion of Taylor bubbles. Based on the present results, a new formula for the evaluation of bubble shape is derived. Both the shape of Taylor bubbles and the bubble rise velocity predicted by the proposed model agree well with experimental observations. Furthermore, the present model shows good promise in predicting the coalescence of Taylor bubbles

Knowledge about Inquiry: A Study in South African High Schools

Science.gov (United States)

Gaigher, Estelle; Lederman, Norman; Lederman, Judith

2014-01-01

This paper reports a study on South African learners' knowledge about scientific inquiry using the Views About Scientific Inquiry (VASI) Questionnaire. The sample consisted of 105 grade 11 learners from 7 schools across the socio-economic spectrum in a South African city. A rubric for scoring the VASI Questionnaire was developed and refined during…

Access to Schooling in a Post-Apartheid South Africa: Linking Concepts to Context

Science.gov (United States)

Fataar, Aslam

1997-07-01

This paper focuses on the policy issue of expanding schooling in a post-apartheid South Africa. The Project of placing about two million children of school-going age in school is viewed as central to the rebuilding of South Africa. The paper argues that this project should be located within the peculiar history of this country's educational underdevelopment. Challenging the constraining influence of the New Right context should be central in conceptualising the provision of expanded school access. Access policy should be based on a notion of educational development that is linked to the overall socioeconomic development of this society. The view is promoted in this paper that a policy of quantitative expansion of schooling should not ignore the quality of such schooling.

The Rayleigh-Taylor instability in the spherical pinch

International Nuclear Information System (INIS)

Chen, H.B.; Hilko, B.; Panarella, E.

1994-01-01

The spherical pinch (SP) concept is an outgrowth of the inertial confinement model (ICF). Unlike the ICF where instabilities, especially the Rayleigh-Taylor instability, have been studied extensively, the instability study of the spherical pinch has just begun. The Raleigh-Taylor instability is investigated for the first time in the SP in the present work. By using the simple condition for the Rayleigh-Taylor instability ∇p · ∇p < O (density and pressure gradients have opposite direction), we have qualitatively identified the regions for development of instabilities in the SP. It is found that the explosion phase (central discharge) is stable and instabilities take place in the imploding phase. However, the growth rate for the instability is not in exponential form, and the appearance of the Rayleigh-Taylor instability does not prevent the main shock wave from converging to the center of the sphere

G.I. Taylor and the Trinity Test

Science.gov (United States)

Deakin, Michael A. B.

2011-01-01

The story is often told of the calculation by G.I. Taylor of the yield of the first ever atomic bomb exploded in New Mexico in 1945. It has indeed become a staple of the classroom whenever dimensional analysis is taught. However, while it is true that Taylor succeeded in calculating this figure at a time when it was still classified, most versions…

School For The Future - Building a School in South African Republic

Directory of Open Access Journals (Sweden)

Anja Planišček

2012-01-01

Full Text Available A team of students and mentors from the Faculty of Architecture, University of Ljubljana joined an international network of architectural schools for the construction of public buildings in developing countries. The network is led by an Austrian foundation called SARCH, Social Sustainable Architecture, from Vienna. The team has designed and built two school premises in the educational complex of Ithuba Community College in Magagula Heights Township, one of the shanty towns in Johannesburg in the Republic of South Africa. The first building was a classroom with a library in 2010, and the second a multipurpose hall in 2011.

Effects of shock waves on Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Zhang Yongtao; Shu Chiwang; Zhou Ye

2006-01-01

A numerical simulation of two-dimensional compressible Navier-Stokes equations using a high-order weighted essentially nonoscillatory finite difference shock capturing scheme is carried out in this paper, to study the effect of shock waves on the development of Rayleigh-Taylor instability. Shocks with different Mach numbers are introduced ahead or behind the Rayleigh-Taylor interface, and their effect on the transition to instability is demonstrated and compared. It is observed that shock waves can speed up the transition to instability for the Rayleigh-Taylor interface significantly. Stronger shocks are more effective in this speed-up process

Understanding Distributed Leadership in South African Schools: Challenges and Prospects

Science.gov (United States)

Sibanda, Lucy

2017-01-01

Prior to 1994, the South African education system was entrenched by authoritarian leadership in which ultimate authority was vested in school principals and power was not distributed to other members of the school. However, the importance of distributed leadership has increasingly gained prominence across the world. After apartheid in 1994, the…

Leadership Development Challenges in South African Schools: The Advanced Certificate: Education (School Management and Leadership)

Science.gov (United States)

Ngcobo, T.

2012-01-01

A number of schools in South Africa appear to be struggling with the changes that the government is introducing to improve the quality of education and lay a strong foundation for the country's societal transformation. Leadership has been found to be one of the factors that are associated with how schools cope with change and its complexities.…

Middle School Students' Motivation for Learning Technology in South Korea

Science.gov (United States)

Kwon, Hyuksoo

2016-01-01

This study aims to develop a feasible instrument for determining middle school students' motivation to learn technology in South Korea. The authors translated Glynn's motivational instrument and modified it to measure Korean middle school students' motivation to learn technology. The instrument was applied to 441 students of grade 8 and 9 from six…

Bright and durable field emission source derived from refractory taylor cones

Science.gov (United States)

Hirsch, Gregory

2016-12-20

A method of producing field emitters having improved brightness and durability relying on the creation of a liquid Taylor cone from electrically conductive materials having high melting points. The method calls for melting the end of a wire substrate with a focused laser beam, while imposing a high positive potential on the material. The resulting molten Taylor cone is subsequently rapidly quenched by cessation of the laser power. Rapid quenching is facilitated in large part by radiative cooling, resulting in structures having characteristics closely matching that of the original liquid Taylor cone. Frozen Taylor cones thus obtained yield desirable tip end forms for field emission sources in electron beam applications. Regeneration of the frozen Taylor cones in-situ is readily accomplished by repeating the initial formation procedures. The high temperature liquid Taylor cones can also be employed as bright ion sources with chemical elements previously considered impractical to implement.

Adolescent Weight Status and Self-Reported School Performance in South Korea

OpenAIRE

Do, Young Kyung; Finkelstein, Eric Andrew

2011-01-01

Using a nationally representative sample of 142 783 middle school (13–15 years old) and high school (16–18 years old) students in South Korea, this study examined whether (1) overweight and obesity are more likely to be associated with lower self-reported school performance; (2) overweight and obese students are more likely to enrol in a vocational high school as opposed to a general high school; (3) the association between obesity and poorer self-reported school performance is mediated throu...

Teachers’ use of a school library in a South African township school: closing the literacy gap

Directory of Open Access Journals (Sweden)

Nicoline Wessels

2012-12-01

Full Text Available This post-project study investigates the use of the school library at a primary school by teachers at the end of a literacyproject, without the guidance of the project facilitators at the school. The article gives background information about theAcademic Literacy Research Project Unit (ALRU from the University of South Africa which established a school library atschool P as part of the literacy research project. The aim of the Literacy Project was to improve literacy levels and createa strong reading culture that would later have a positive impact on the academic progress of learners at school P. TheLiteracy Project involved training teachers in literacy and reading matters. In addition to the teacher training, a schoollibrarian was trained to manage the school library. At the onset of the post-project study, self-administered questionnaireswere drawn up to collect data on the teachers’ school library practices after withdrawal of the project team. Thequestionnaires included qualitative and quantitative questions. The findings suggest that the school library is being utilisedand appreciated as an integral part of the learning process; however, the teachers seem to need further exposure andtraining on information literacy. The authors hope that the information and interpretations provided in this article will behelpful in achieving the goal of quality education in South Africa and especially in improving the reading and literacy levelsof all learners.

Shifting the Future? Teachers as Agents of Social Change in South African Secondary Schools

Science.gov (United States)

Cappy, Christina Lane

2016-01-01

South Africa has risen to the forefront of educational debates that claim schooling can promote social justice and social cohesion. By drawing on Freire's (1970) theory of critical pedagogy, this paper examines how South African teachers in rural and township schools encourage students to reflect critically upon their own lives and take action to…

Teachers' confidence in teaching HIV/AIDS and sexuality in South African and Tanzanian schools.

Science.gov (United States)

Helleve, Arnfinn; Flisher, Alan J; Onya, Hans; Kaaya, Sylvia; Mukoma, Wanjiru; Swai, Caroline; Klepp, Knut-Inge

2009-06-01

This study aimed to investigate how confident and comfortable teachers at Tanzanian and South African urban and rural schools are in teaching HIV/AIDS and sexuality. It also aimed at identifying factors associated with teacher confidence and investigated how reported confidence was associated with the implementation of educational programmes on HIV/AIDS and sexuality. A survey was conducted among South African grade 8 and 9 Life Orientation teachers, and among science teachers for grade 5 to 7 in public primary schools in Tanzania. Teachers' confidence levels were measured on a four-item scale (0-3). A total number of 266 teachers participated in a survey in 86 schools in South Africa and Tanzania. Overall, teachers report to be rather confident in teaching HIV/AIDS and sexuality. Tanzanian teachers reported higher levels of confidence then did their South Africa colleagues (2.1 vs. 1.8; p teaching was significantly associated with the numbers of years teaching HIV/AIDS and sexuality, formal training in these subjects, experience in discussing the topics with others, school policy and priority given to teaching HIV/AIDS and sexuality at school. Finally, confidence in teaching remained positively associated with self-reported successful implementation of school-based programmes after adjusting for gender, age, religion and numbers of years teaching HIV/AIDS and sexuality. Across urban and rural sites in South Africa and Tanzania teachers reported to be fairly confident in teaching HIV/AIDS and sexuality. Further strengthening of their confidence levels could, however, be an important measure for improving the implementation of such programmes.

Namesake Schools: Vulnerable Places and Cultural Narratives of the South

Science.gov (United States)

Agosto, Vonzell; Kyobe, Charles; Elam, Donna

2017-01-01

Geographic place and socio-political space are salient in struggles for justice in education. Social geography provides a frame for discussing the relationship between names of schools and narratives of race, place, and justice (racial and spatial) in the US South. Featured herein is an illustrative case of how a school named after an African…

A Narrative Inquiry into Rural School Leadership in South Africa

Science.gov (United States)

Smit, Brigitte

2017-01-01

This article attends to rural school leadership in two South African schools through the lens of the concepts of relational leadership and emotional labour. The inquiry draws on five years of guided conversations and observations that speak to leadership experiences of hope and anticipation as well as despair and disillusionment. I worked with one…

A Qualitative Analysis of Facilities Maintenance--A School Governance Function in South Africa

Science.gov (United States)

Xaba, M. I.

2012-01-01

I analysed school facilities maintenance, a school governance function in South Africa. Qualitative interviews were conducted with 13 principals and three deputy principals as coordinators of this function at their schools. The interviews were purposively and conveniently selected to gather data regarding school facilities maintenance and gain…

Factors Affecting Aggression in South Korean Middle School Students

OpenAIRE

MiJeong Park, PhD, RN; Jihea Choi, PhD, RN, CPNP; Seung-Joo Lim, PhD, RN

2014-01-01

Purpose: The study was undertaken to assess levels of aggression, and to determine factors affecting aggression among South Korean middle school students. Methods: A descriptive study was conducted using self-report questionnaires. The participants were 340 girls and boys from two middle schools and 302 questionnaires were used for the final data analysis. Aggression, academic stress, depression, self esteem, decision-making competency, and happiness were measured. Data were analyzed using...

Teenage Pregnancy and Parenting at School in Contemporary South African Contexts: Deconstructing School Narratives and Understanding Policy Implementation

Science.gov (United States)

Shefer, Tamara; Bhana, Deevia; Morrell, Robert

2013-01-01

South African national education policy is committed to promoting gender equality at school and to facilitating the successful completion of all young people's schooling, including those who may become pregnant and parent while at school. However, the experience of being pregnant and parenting while being a learner is shaped by broader social and…

Experiments on the Taylor system with an axial flow

International Nuclear Information System (INIS)

Tsameret, Avraham.

1993-02-01

This work is an experimental study of the Taylor system with a superimposed axial flow. The convective and absolute instability lines which are associated with the propagating Taylor vortices are measured. A quantitative agreement is found with the theoretical predictions. Noise-sustained structures are found to exist in the convectively unstable region, above a critical value of the through flow. These structures are propagating Taylor vortices that are characterized by a noisy power spectrum and irregular temporal dynamics of velocity amplitude. At the absolute instability line the power spectrum of the propagating Taylor vortices exhibits transition to a sharp peak, and the amplitude of the propagating Taylor vortices becomes stationary. The mechanism that generates the noise-sustained structures is identified with a process of permanent amplification of noise that is generated mainly near the inlet boundary. The intrinsic noise in the system is studied. This study is motivated by the question of whether the noise which generates the noise-sustained structures is thermal. The intensity of the intrinsic noise is estimated by several methods, which includes a comparison of data with numerical simulations of the amplitude equation with a noise term. It is found that the intrinsic noise is not thermal, although its intensity reaches the thermal noise level at small through-flow velocities. Novel states are manifested in the system as a result of interaction between the propagating Taylor vortices and spiral modes. These states are studied and their spatial and temporal properties are analyzed. (author)

Group Counseling with South Asian Immigrant High School Girls: Reflections and Commentary of a Group Facilitator

Science.gov (United States)

Thakore-Dunlap, Ulash; Van Velsor, Patricia

2014-01-01

The diversity of the U.S. school population speaks to a need to provide support for youth from various backgrounds. As a school-based mental health counselor, the first author observed that the South Asian immigrant students at her school did not utilize any of the counseling services provided. Because South Asians are typically collectivistic,…

Animating Nested Taylor Polynomials to Approximate a Function

Science.gov (United States)

Mazzone, Eric F.; Piper, Bruce R.

2010-01-01

The way that Taylor polynomials approximate functions can be demonstrated by moving the center point while keeping the degree fixed. These animations are particularly nice when the Taylor polynomials do not intersect and form a nested family. We prove a result that shows when this nesting occurs. The animations can be shown in class or…

The 1968 Edcouch-Elsa High School Walkout: Chicano Student Activism in a South Texas Community

Science.gov (United States)

Barrera, James B.

2004-01-01

A nonviolent school boycott by 192 Chicanola students in 1968 at Edcouch-Elsa high school in the Rio Grande Valley region of Deep South Texas is examined. This walkout was the first major Chicano student protest in South Texas, and was a product of the 1960s Chicano movement.

The Management of Parental Involvement in Multicultural Schools in South Africa: A Case Study

Directory of Open Access Journals (Sweden)

Sathiapama Michael

2012-01-01

Full Text Available The aim of this study was to investigate the management of parental involvement in three multicultural schools in the Umlazi District in Durban, South Africa. A literature survey resulting in a theoretical framework on parental involvement in schools, multicultural schools, and the managing of parental involvement in schools has been done. The contextual background of schools in contemporary South Africa is depicted. A qualitative research design has been used. Focus group discussions have been conducted, with a total of thirty-three principals, teachers and parents. It has found that there is a low level of meaningful contact between school and parents. Apathy exists on the side of parents, low expectations on the side of principals and teachers, and an organisational structure facilitating parent-school interaction is lacking. In managing parental involvement in multicultural schools, school managers display a lack of intercultural sensitivity.

Instabilities with polyacrylamide solution in small and large aspect ratios Taylor-Couette systems

International Nuclear Information System (INIS)

Smieszek, M; Egbers, C; Crumeyrolle, O; Mutabazi, I

2008-01-01

We have investigated the stability of viscoelastic polyacrylamide solution in Taylor-Couette system with different aspect ratios. The first instability modes observed in a Taylor-Couette system with Γ = 10 were TVF and WVF, as for Newtonian fluid. At higher Taylor numbers moving vortices occur, a wavy mode with non-stationary vortex size. In the Taylor-Couette system with Γ = 45.9 we note a coexistence of various instability modes. In addition to TVF, counterpropagating waves developed at the transition from the base state flow. At higher Taylor number values Taylor vortices of different sizes occurred. Reduced amplitude Wavy vortex flow has also been observed.

Corporal punishment in South African schools: a neglected ...

African Journals Online (AJOL)

South African Journal of Education, 2001, 21(4). 292. Nomdo L ... It is based on a survey of 16 Durban schools in September and .... Discipline continues to be considered a major problem by .... Examining corporal punishment from an historical perspective ..... As indicated, the main data-gathering instrument was the ques-.

Repainting, modifying, smashing Taylorism

NARCIS (Netherlands)

H.D. Pruijt (Hans)

2000-01-01

textabstractAbstract Survey data show that post-Tayloristic production concepts are not developing to the extent that many researchers had originally expected. It also is inadequate to portray post-Taylorism as a development that is happening, but just slower than expected. This is inadequate

Rayleigh-Taylor instability and mixing in SN 1987A

International Nuclear Information System (INIS)

Ebisuzaki, T.; Shigeyama, T.; Nomoto, K.

1989-01-01

The stability of the supernova ejecta is compared with the Rayleigh-Taylor instability for a realistic model of SN 1987A. A linear analysis indicates that the layers around the composition interface between the hydrogen-rich and helium zones, and become Rayleigh-Taylor unstable between the helium and metal zones. In these layers, the pressure increases outward because of deceleration due to the reverse shock which forms when the blast shock hits the massive hydrogen-rich envelope. On the contrary, the density steeply decreases outward because of the preexisting nuclear burning shell. Then, these layers undergo the Raleigh-Taylor instability because of the opposite signs of the pressure and density gradients. The estimated growth rate is larger than the expansion rate of the supernova. The Rayleigh-Taylor instability near the composition interface is likely to induce mixing, which has been strongly suggested from observations of SN 1987A. 25 refs

Broadband in schools: towards a definition and model of broadband for South African schools

CSIR Research Space (South Africa)

Ford, Merryl

2017-05-01

Full Text Available South Africa is about to provide broadband internet connectivity to all schools in the country via the implementation of the national broadband policy. The challenge is to ensure a balance between the schools’ demand-side usage and supply...

Dynamics of helicity transport and Taylor relaxation

International Nuclear Information System (INIS)

Diamond, P.H.; Malkov, M.

2003-01-01

A simple model of the dynamics of Taylor relaxation is derived using symmetry principles alone. No statistical closure approximations are invoked or detailed plasma model properties assumed. Notably, the model predicts several classes of nondiffusive helicity transport phenomena, including traveling nonlinear waves and superdiffusive turbulent pulses. A universal expression for the scaling of the effective magnetic Reynolds number of a system undergoing Taylor relaxation is derived. Some basic properties of intermittency in helicity transport are examined

School Quality, Clustering and Government Subsidy in Post-Apartheid South Africa

Science.gov (United States)

Yamauchi, Futoshi

2011-01-01

This paper examines a range of historical and geographic factors that determine the quality of public school education in post-apartheid South Africa. Empirical analysis shows, first, that population groups are still spatially segregated due to the legacy of apartheid, which implies that, given the positive correlation between school quality and…

High Speed Solution of Spacecraft Trajectory Problems Using Taylor Series Integration

Science.gov (United States)

Scott, James R.; Martini, Michael C.

2008-01-01

Taylor series integration is implemented in a spacecraft trajectory analysis code-the Spacecraft N-body Analysis Program (SNAP) - and compared with the code s existing eighth-order Runge-Kutta Fehlberg time integration scheme. Nine trajectory problems, including near Earth, lunar, Mars and Europa missions, are analyzed. Head-to-head comparison at five different error tolerances shows that, on average, Taylor series is faster than Runge-Kutta Fehlberg by a factor of 15.8. Results further show that Taylor series has superior convergence properties. Taylor series integration proves that it can provide rapid, highly accurate solutions to spacecraft trajectory problems.

The quest for a culture of learning: a South African schools perspective

African Journals Online (AJOL)

The quest for a culture of learning: a South African schools perspective. ... at gaining conceptual clarity as to what is meant by a “culture of learning” and exploring ... in the social interaction taking place within classrooms, schools and learning ...

Corporal punishment in South African schools : a neglected ...

African Journals Online (AJOL)

The South African education system historically has used corporal punishment to maintain discipline. Criticism of its effects led, in 1996, to the banning of this form of punishment. But this legislative intervention did not end the use of corporal punishment in schools. This article offers an explanation for the ongoing use of ...

The Efficacy of "Catch-Up Programmes" in South African High Schools: A Legal Jinx

Science.gov (United States)

Nyoni, Jabulani

2013-01-01

The South African State is mandated by Sections 28(2) and 29(1) of the South African Constitution to make provision for the education of a South African child in fulfilment of the child's constitutional rights. Teacher Unions (TUs) and provincial Departments of Basic Education (DBEs) have often promised South African high school student body, in…

Vortex formation in Taylor-Couette flow with weakly spatial modulation

International Nuclear Information System (INIS)

Li, Z.; Khayat, R.E.

2002-01-01

The onset of the vortex structure in axisymmetric Taylor-Couette flow with spatially modulated cylinders is examined. The modulation amplitude is assumed to be small for a regular perturbation solution to be sought at small to moderate Taylor numbers. It is found that the presence of a weak modulation of the outer or inner cylinders leads unavoidably to the emergence of steady vortex flow even for a vanishingly small Taylor number. This situation is reminiscent of the onset of an imperfect bifurcation. The vortex structure of the forced TVF is found to have same periodicity when only one cylinder is modulated or the two modulations are commensurate for the Taylor number measured. The vortex structure is quasi-periodic when the two modulations are incommensurate. For a certain Taylor number, there exists a critical wavelength for the presence of the strongest vortex flow when the modulation is in the form of sinusoidal. This critical wavelength tends to the critical value predicted by the linear stability analysis when Ta approaches the supercritical value. (author)

How teachers of English in South African schools recognise their ...

African Journals Online (AJOL)

How teachers of English in South African schools recognise their change agency. ... values consistent with the fundamental rights contained in the Constitution of ... Keywords: change agency; democracy; empowerment; teachers of English ...

A design of inverse Taylor projectiles using material simulation

International Nuclear Information System (INIS)

Tonks, Michael; Harstad, Eric; Maudlin, Paul; Trujillo, Carl

2008-01-01

The classic Taylor cylinder test, in which a right circular cylinder is projected at a rigid anvil, exploits the inertia of the projectile to access strain rates that are difficult to achieve with more traditional uniaxial testing methods. In this work we present our efforts to design inverse Taylor projectiles, in which a tapered projectile becomes a right circular cylinder after impact, from annealed copper and show that the self-correcting geometry leads to a uniform compressive strain in the radial direction. We design projectiles using finite element simulation and optimization that deform as desired in tests with minor deviations in the deformed geometry due to manufacturing error and uncertainty in the initial velocity. The inverse Taylor projectiles designed in this manner provide a simple means of validating constitutive models. This work is a step towards developing a general method of designing Taylor projectiles that provide stress–strain behavior relevant to particular engineering problems

Techniques for optimizing nanotips derived from frozen taylor cones

Science.gov (United States)

Hirsch, Gregory

2017-12-05

Optimization techniques are disclosed for producing sharp and stable tips/nanotips relying on liquid Taylor cones created from electrically conductive materials with high melting points. A wire substrate of such a material with a preform end in the shape of a regular or concave cone, is first melted with a focused laser beam. Under the influence of a high positive potential, a Taylor cone in a liquid/molten state is formed at that end. The cone is then quenched upon cessation of the laser power, thus freezing the Taylor cone. The tip of the frozen Taylor cone is reheated by the laser to allow its precise localized melting and shaping. Tips thus obtained yield desirable end-forms suitable as electron field emission sources for a variety of applications. In-situ regeneration of the tip is readily accomplished. These tips can also be employed as regenerable bright ion sources using field ionization/desorption of introduced chemical species.

Researching the Nokia Mobile Mathematics Service in South Africa

African Journals Online (AJOL)

2012), in large scale systemic evaluations of the South African educational landscape (Taylor, Draper, Muller &. Sithole .... technical problems, including lack of network cov- erage, lack ... fee and the data costs (of traffic to and from the service) ...

Indoor radon levels in schools of South-East Italy

International Nuclear Information System (INIS)

Trevisi, Rosabianca; Leonardi, Federica; Simeoni, Carla; Tonnarini, Sabrina; Veschetti, Miriam

2012-01-01

A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educational buildings (506 schools) located in South-East Italy (the Salento peninsula, province of Lecce). In this paper the final findings relating to measurements performed with SSNTD dosemeters in 438 schools (86% of the sample) are reported. The average annual activity concentration of radon in schools located in the province of Lecce is 209 ± 9 Bq/m 3 . Radon values actually ranged from 21 Bq/m 3 to 1608 Bq/m 3 . About 7% of schools showed radon concentration values above 500 Bq/m 3 , the Italian action level for workplaces. - Highlights: ► The annual radon concentration in schools of the province of Lecce is 209 ± 9 Bq/m 3 . ► Schools radon values (209 ± 9 Bq/m 3 ) are higher than the regional average (52 ± 2 Bq/m 3 ). ► Nursery schools showed higher radon values. ► Nursery schools had the highest percentage of schools (12%) over 500 Bq/m 3 .

PREFACE: The 15th International Couette-Taylor Worskhop

Science.gov (United States)

Mutabazi, Innocent; Crumeyrolle, Olivier

2008-07-01

The 15th International Couette-Taylor Worskhop (ICTW15) was held in Le Havre, France from 9-12 July 2007. This regular international conference started in 1979 in Leeds, UK when the research interest in simple models of fluid flows was revitalized by systematic investigation of Rayleigh-Bénard convection and the Couette-Taylor flow. These two flow systems are good prototypes for the study of the transition to chaos and turbulence in closed flows. The workshop themes have been expanded from the original Couette-Taylor flow to include other centrifugal instabilities (Dean, Görtler, Taylor-Dean), spherical Couette flows, thermal convection instabilities, MHD, nonlinear dynamics and chaos, transition to turbulence, development of numerical and experimental techniques. The impressive longevity of the ICTW is due to the close interaction and fertile exchanges between international research groups from different disciplines: Physics and Astrophysics, Applied Mathematics, Mechanical Engineering, Chemical Engineering. The present workshop was attended by 100 participants, the program included over 83 contributions with 4 plenary lectures, 68 oral communications and 17 posters. The topics include, besides the classical Couette-Taylor flows, the centrifugal flows with longitudinal vortices, the shear flows, the thermal convection in curved geometries, the spherical Couette-Taylor flow, the geophysical flows, the magneto-hydrodynamic effects including the dynamo effect, the complex flows (viscoelasticity, immiscible fluids, bubbles and migration). Selected papers have been processed through the peer review system and are published in this issue of the Journal of Physics: Conference Series. The Workshop has been sponsored by Le Havre University, the Region Council of Haute-Normandie, Le Havre City Council, CNRS (ST2I, GdR-DYCOEC), and the European Space Agency through GEOFLOW program. The French Ministry of Defense (DGA), the Ministry of Foreign Affairs, the Ministry of

South African medical schools: Current state of selection criteria and ...

African Journals Online (AJOL)

Selection of medical students at South African (SA) medical schools must promote ... groups, while ensuring optimal student throughput and success, and training future ... In keeping = with international practices, a variety of academic and ...

The legislative framework regarding bullying in South African schools

African Journals Online (AJOL)

... the South African Schools Act 84 of 1996 call for critical analysis. KEYWORDS: Abuse; best interest of the child; bullying; child justice; children's rights; code of conduct; constitutional rights; discipline; educational context; harassment; harm; offender; protection orders; restorative justice; right to education; victim; violence.

DSM-5 and ADHD - an interview with Eric Taylor.

Science.gov (United States)

Taylor, Eric

2013-09-12

In this podcast we talk to Prof Eric Taylor about the changes to the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in DSM-5 and how these changes will affect clinical practice. The podcast for this interview is available at: http://www.biomedcentral.com/sites/2999/download/Taylor.mp3.

South Dakota School Principals' Preferred Leadership Styles for Leading Change to Face Poverty and Discrimination

Science.gov (United States)

Soka, John Alex

2011-01-01

This quantitative research study identified perceptions regarding leadership styles of a sample of high school, middle school, and elementary school principals serving in South Dakota public and tribal/BIE (Bureau of Indian Education) schools in 2011. From 152 public school districts and 20 tribal/BIE schools, a sample of 148 school principals was…

Problematising the Standardisation of Leadership and Management Development in South African Schools

Science.gov (United States)

Williams, Clarence

2015-01-01

In 2007 the Department of Education introduced the standards-based Advanced Certificate in Education: School Management and Leadership. The standardisation of leadership and management development in South African schools has been uncritically accepted by most academics and professionals. The purpose of this article is to problematise the…

The curriculum ideology of the South African secondary school Biology

African Journals Online (AJOL)

Nelson Mandela stated that education is the tool that can be used to change the world. ... the overarching objective of the South African school's curriculum, with specific reference to ..... International journal of historical learning, teaching and.

Sustainable Environmental Management Indicators in South African Primary Schools

Directory of Open Access Journals (Sweden)

Luiza O. de Sousa

2017-05-01

Full Text Available This research explores sustainable environmental management indicators in South African primary schools. Of key interest is the comparison of a township, farm and urban primary school that identify indicators that promote education for sustainable development in schools that implement an environmental management system. Data are drawn from one-on-one interviews, focus group interviews, observations and document analysis from 35 participants in three schools. A comparison of the three schools was done by content and thematic analysis of a within-case analysis. Data from the township school revealed that socioeconomic factors and organisational structure promote education for sustainable development. The farm school data revealed that health promotion can be managed within an environmental management system within a hierarchical school structure. The urban school data revealed that an economic inducement brings a school to realise that it can reduce its carbon footprint, gain financially and utilize its resources with innovation. A case is made that the four pillars of sustainable development (environment, society, economy, and governance endorse education for sustainable development. Furthermore, the objectives of environmental education ought to remain nested in an environmental management system to ensure that the global goal of quality education is achieved.

The management of AIDS in South African schools

Directory of Open Access Journals (Sweden)

Izak Oosthuizen

1994-03-01

Full Text Available According to the Third National Survey conducted among women attending antenatal clinics in South Africa, 120,000 more people are estimated to have become infected with HIV since 1991 (Kustner, 1993a:34. Pupils and schools cannot be isolated from this serious health hazard in our country. In this article the relationship o f confidentiality between a doctor and his patient is compared to the relationship between a pupil and a teacher. The question arises as to whether a teacher (i.e. the school principal should be allowed to breach this confidence by revealing to the staff of his school the fa c t that a pupil is HIV-infected. Under certain circumstances the public interest in preserving human life outweighs the HIV-infected pupil's right to privacy.

Misery in Dark Shadows behind the High Achievement Scores in South Korean Schooling: An Ethnographic Study

Science.gov (United States)

Kwon, Soonjung; Kristjánsson, Kristján; Walker, David I.

2017-01-01

This article explores some of the hidden background behind the highly praised school results in South Korea. An ethnographic case study is used to cast light on how schooling is actually experienced by South Korean students. Two main results are reported from these data. First, evidence is presented of damaging "cultural elements" such…

Compression of an Accelerated Taylor State in SSX

Science.gov (United States)

Shrock, J. E.; Suen-Lewis, E. M.; Barbano, L. J.; Kaur, M.; Schaffner, D. A.; Brown, M. R.

2017-10-01

In the Swarthmore Spheromak Experiment (SSX), compact toroidal plasmas are launched from a plasma gun and evolve into minimum energy twisted Taylor states. The plumes initially have a velocity 40 km/s, density 0.4 ×1016 cm-3 , and proton temperature 20 eV . After formation, the plumes are accelerated by pulsed pinch coils with rise times τ1 / 4 = (π / 2) √{ LC } less than 1 μ s and currents Ipeak =V0 / Z =V0 /√{ L / C } on the order of 104 A. The accelerated Taylor States are abruptly stagnated in a copper flux conserver, and over the course of t plasma, the other to particle motion parallel to the field. We observe Taylor state compression most in agreement with the parallel equation of state: d / dt (P∥B2 /n3) = 0 . DOE ARPA-E ALPHA Program.

Nonlinear saturation of the Rayleigh endash Taylor instability

International Nuclear Information System (INIS)

Das, A.; Mahajan, S.; Kaw, P.; Sen, A.; Benkadda, S.; Verga, A.

1997-01-01

A detailed numerical simulation of the nonlinear state of the Rayleigh endash Taylor instability has been carried out. There are three distinct phases of evolution where it is governed by the (i) linear effects, (ii) effects arising from the conventional nonlinear terms and (iii) subtle nonlinear effects arising through the coupling terms. During the third phase of evolution, there is a self-consistent generation of shear flow which saturates the Rayleigh endash Taylor instability even in situations (with periodic boundaries) where, in principle, an infinite amount of gravitational energy can be tapped. The Galerkin approximation is presented to provide an understanding of our numerical findings. Last, there is an attempt to provide a comprehensive understanding of the nonlinear state of the Rayleigh endash Taylor instability by comparing and contrasting this work with earlier studies. copyright 1997 American Institute of Physics

Corporal Punishment in Schools and Fundamental Human Rights: A South African Perspective.

Science.gov (United States)

Prinsloo, Justus

In many western countries, corporal punishment has been abolished as a form of punishment in criminal trials and in schools. Under South African common law, persons entitled to enforce discipline may inflict corporal punishment within certain guidelines established by the Supreme Court. For the first time in the Republic of South Africa (RSA), the…

On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

Science.gov (United States)

LeBoeuf, Richard L.; Mehta, Rabindra D.

1995-01-01

In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

Shapes of an Air Taylor Bubble in Stagnant Liquids Influenced by Different Surface Tensions

Science.gov (United States)

Lertnuwat, B.

2018-02-01

The aim of this work is to propose an empirical model for predicting shapes of a Taylor bubble, which is a part of slug flows, under different values of the surface tension in stagnant liquids by employing numerical simulations. The k - Ɛ turbulence model was used in the framework of finite volume method for simulating flow fields in a unit of slug flow and also the pressure distribution on a Taylor bubble surface. Assuming that an air pressure distribution inside the Taylor bubble must be uniform, a grid search method was exploited to find an appropriate shape of a Taylor bubble for six values of surface tension. It was found that the shape of a Taylor bubble would be blunter if the surface tension was increased. This was because the surface tension affected the Froude number, controlling the flow around a Taylor bubble. The simulation results were also compared with the Taylor bubble shape, created by the Dumitrescu-and-Taylor model and former studies in order to ensure that they were consistent. Finally, the empirical model was presented from the simulation results.

Preliminary study of Rayleigh-Taylor instability in wire-array Z-pinch

International Nuclear Information System (INIS)

He Kaihui; Feng Kaiming; Li Qiang; Gao Chunming

2000-01-01

It is important to research into the MHD Rayleigh-Taylor instability developed in Z-pinch implosion. A snowplough model of the single wire Z-pinch is presented. The perturbation amplitude of Rayleigh-Taylor instability in the wire-array Z-pinch is analyzed quantitatively. Sheared axial flow is put forward to mitigate and reduce the Rayleigh-Taylor instability. And other approaches used to mitigate MHD instability in such a super-fast process are explored

An algorithm for symplectic implicit Taylor-map tracking

International Nuclear Information System (INIS)

Yan, Y.; Channell, P.; Syphers, M.

1992-10-01

An algorithm has been developed for converting an ''order-by-order symplectic'' Taylor map that is truncated to an arbitrary order (thus not exactly symplectic) into a Courant-Snyder matrix and a symplectic implicit Taylor map for symplectic tracking. This algorithm is implemented using differential algebras, and it is numerically stable and fast. Thus, lifetime charged-particle tracking for large hadron colliders, such as the Superconducting Super Collider, is now made possible

Training Middle Managers of South African Public Schools in Leadership and Management Skills

Science.gov (United States)

Mampane, Sharon Thabo

2017-01-01

The purpose of this conceptual explanatory research is to highlight the importance of training of Middle Managers or Heads of Department (HoDs) in leadership and management in South African public schools. Leadership responsibilities in schools are becoming more complex to the extent that principals can no longer be sole leaders in schools. The…

78 FR 12307 - Taylor, G. Tom; Notice of Filing

Science.gov (United States)

2013-02-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ID-5705-001] Taylor, G. Tom; Notice of Filing Take notice that on February 14, 2013, G. Tom Taylor filed an application to hold interlocking positions pursuant to section 305(b) of the Federal Power Act, 16 U.S.C. 825d(b), Part 45 of the...

Taylor dispersion of nanoparticles

Science.gov (United States)

Balog, Sandor; Urban, Dominic A.; Milosevic, Ana M.; Crippa, Federica; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

2017-08-01

The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical extinction, translational diffusion, and sheer-enhanced dispersion of nanoparticles subjected to a steady laminar flow. The interplay of these defines the apparent size. Considering that particles in fact are never truly uniform nor monodisperse, we rigorously address particle polydispersity and calculate the apparent particle size measured by Taylor dispersion analysis. We conducted case studies addressing aqueous suspensions of model particles and large-scale-produced "industrial" particles of both academic and commercial interest of various core materials and sizes, ranging from 15 to 100 nm. A comparison with particle sizes determined by transmission electron microscopy confirms that our approach is model-independent, non-parametric, and of general validity that provides an accurate account of size polydispersity—independently on the shape of the size distribution and without any assumption required a priori.

Rice Creek Elementary School and the University of South Carolina: A Shared Vision for Excellence

Science.gov (United States)

Evans, Kathy; Holley, Jessica; Richburg-Sellers, Felicia; Robey, Susan; Suber, Shawn; Burton, Megan; Field, Bruce E.

2012-01-01

The 2011 Professional Development Schools National Conference recognized Rice Creek Elementary School for its outstanding collaborative accomplishments with the University of South Carolina, naming it as a recipient of the National Association for Professional Development School's Award for Exemplary Professional Development School Achievement.…

Electrochemical Analysis of Taylor Vortices.

Czech Academy of Sciences Publication Activity Database

Wouahbi, F.; Allaf, K.; Sobolík, Václav

2007-01-01

Roč. 37, 1 (2007) , s. 57-62 ISSN 0021-891X Institutional research plan: CEZ:AV0Z40720504 Keywords : electrodiffusion method * taylor vortices * three-segment electrode Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.417, year: 2007

Numerical simulations of thermal convection in a rotating spherical fluid shell at high Taylor and Rayleigh numbers

International Nuclear Information System (INIS)

Sun, Z.; Schubert, G.

1995-01-01

In this study, we carry out numerical simulations of thermal convection in a rapidly rotating spherical fluid shell at high Taylor number Ta and Rayleigh number R with a nonlinear, three-dimensional, time-dependent, spectral-transform code. The parameters used in the simulations are chosen to be in a range which allows us to study two different types of convection, i.e., single column and multi-layered types, and the transition between them. Numerical solutions feature highly time-dependent north--south open columnar convective cells. The cells occur irregularly in longitude, are quasi-layered in cylindrical radius, and maintain alternating bands of mean zonal flow. The complex convective structure and the banded mean zonal flow are results of the high Taylor and Rayleigh numbers. The transition between the two types of convection appears to occur gradually with increasing Rayleigh and Taylor numbers. At a Taylor number of 10 7 the differential rotation pattern consists of an inner cylindrical region of subrotation and an outer cylindrical shell of superrotation manifest at the outer boundary as an equatorial superrotation and a high latitude subrotation. The differential rotation pattern is similar at Ta=10 8 and low Rayleigh number. Cylindrical shells of alternately directed mean zonal flow begin to develop at Ta=10 8 and R=50R c and at Ta=10 9 and R=25R c . This pattern is seen on the outer surface as a latitudinally-banded zonal flow consisting of an equatorial superrotation, a middle and high latitude subrotation, and a polar superrotation. At Ta=10 9 and R=50R c the differential rotation appears at the surface as a broad eastward flow in the equatorial region with alternating bands of westward and eastward flow at high latitudes. copyright 1995 American Institute of Physics

An endogenous Taylor condition in an endogenous growth monetary policy model

OpenAIRE

Le, Mai Vo; Gillman, Max; Minford, Patrick

2007-01-01

The paper derives a Taylor condition as part of the agent's equilibrium behavior in an endogenous growth monetary economy. It shows the assumptions necessary to make it almost identical to the original Taylor rule, and that it can interchangably take a money supply growth rate form. From the money supply form, simple policy experiments are conducted. A full central bank policy model is derived that includes the Taylor condition along with equations comparable to the standard aggregate-demand/...

Factors affecting condom use among junior secondary school pupils in South Africa

Directory of Open Access Journals (Sweden)

Karl Peltzer

2000-10-01

Full Text Available The aim of the study is to investigniefi2ctors affecting condom use among junior Secondary School pupi1s in South Africa. The sample included 446 Grade 10 Secondary school pupils, 200 (44.896 ma1e and 246 (55.2%,females within the age range of I0 to 30 years (M age 16.6 years, SD = 2.5 from three rural schools in one region of the Northern Province in South Africa. Main outcomes measures included sexual activity and condom use (12 items, source of “condom” information (12 items, knowledge of correct condom use (10 items, a 16-item AIDS Health Belief Scale and a 28-item Condom Use Self-Efficiency Scale. *Please note: This is a reduced version of the abstract. Please refer to PDF for full text.

New phenomena in variable-density Rayleigh-Taylor turbulence

Energy Technology Data Exchange (ETDEWEB)

Livescu, D; Ristorcelli, J R; Petersen, M R; Gore, R A, E-mail: livescu@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-12-15

This paper presents several issues related to mixing and turbulence structure in buoyancy-driven turbulence at low to moderate Atwood numbers, A, found from direct numerical simulations in two configurations: classical Rayleigh-Taylor instability and an idealized triply periodic Rayleigh-Taylor flow. Simulations at A up to 0.5 are used to examine the turbulence characteristics and contrast them with those obtained close to the Boussinesq approximation. The data sets used represent the largest simulations to date in each configuration. One of the more remarkable issues explored, first reported in (Livescu and Ristorcelli 2008 J. Fluid Mech. 605 145-80), is the marked difference in mixing between different density fluids as opposed to the mixing that occurs between fluids of commensurate densities, corresponding to the Boussinesq approximation. Thus, in the triply periodic configuration and the non-Boussinesq case, an initially symmetric density probability density function becomes skewed, showing that the mixing is asymmetric, with pure heavy fluid mixing more slowly than pure light fluid. A mechanism producing the mixing asymmetry is proposed and the consequences for the classical Rayleigh-Taylor configuration are discussed. In addition, it is shown that anomalous small-scale anisotropy found in the homogeneous configuration (Livescu and Ristorcelli 2008 J. Fluid Mech. 605 145-80) and Rayleigh-Taylor turbulence at A=0.5 (Livescu et al 2008 J. Turbul. 10 1-32) also occurs near the Boussinesq limit. Results pertaining to the moment closure modelling of Rayleigh-Taylor turbulence are also presented. Although the Rayleigh-Taylor mixing layer width reaches self-similar growth relatively fast, the lower-order terms in the self-similar expressions for turbulence moments have long-lasting effects and derived quantities, such as the turbulent Reynolds number, are slow to follow the self-similar predictions. Since eddy diffusivity in the popular gradient transport hypothesis

Shining Light into Dark Shadows of Violence and Learned Helplessness: Peace Education in South Korean Schools

Science.gov (United States)

Kwon, Soonjung; Walker, David Ian; Kristjánsson, Kristján

2018-01-01

The paper illustrates how a culture of violence is perpetuated and reproduced in South Korea through schooling and argues that peace education could help transform a culture of violence to a culture of peace. Critical ethnographic methods and a framework of peace education were applied to a sample of secondary schools in South Korea to argue that…

Language intervention at schools: changing orientations within the South African context.

Science.gov (United States)

Alant, E

1989-01-01

The role of the speech therapist in the school has changed drastically over the last decade. The reasons for these changes originate from a growing realisation of the importance of contextualising intervention within a particular community. This article aims at providing an analysis of the present school population in South Africa with specific reference to the Black schools as a basis for discussion on the role of the speech and language therapist within this context. The problems of second language learning and teaching are highlighted and the role of the language therapist as a consultant within the Black school system is emphasized.

An architecture for eBook provision to South African schools

CSIR Research Space (South Africa)

Dlodlo, N

2012-11-01

Full Text Available To avert problems associated with text book distribution delays in South African schools, this paper proposes an alternative approach to paper book distribution in the form of eTextbooks. This paper looks at challenges to eTextbook provision...

THE CHALLENGES OF SCHOOL-BASED YOUTH SUICIDE PREVENTION: EXPERIENCES AND PERCEPTIONS OF MENTAL HEALTH PROFESSIONALS IN SOUTH AFRICAN SCHOOLS.

Science.gov (United States)

Woolf, Maryke; Bantjes, Jason; Kagee, Ashraf

2015-01-01

Youth suicidal behaviour poses a significant public health concern. Mental health care professionals working in schools have an important role to play in youth suicide prevention initiatives, although little is known of the experiences of this group of professionals in the developing world. The aim of this study was to explore the experiences of mental health professionals working in South African schools and document their insights, attitudes and beliefs regarding youth suicidal behaviour. In-depth semi-structured interviews were conducted with seven school-based mental health care professionals and data were analysed using Thematic Analysis. Participants reported that they relied on a reactive strategy by responding to youths who were in crisis. They were challenged by a lack of support from faculty staff, lack of access to resources, and heavy caseloads. Findings highlight the need for a proactive and collaborative approach to suicide prevention among mental health care professionals, teachers and parents in South African schools and improved training and supervision.

School Outcomes in New South Wales and Queensland: A Regression Discontinuity Approach

Science.gov (United States)

Miller, Paul W.; Voon, Derby

2014-01-01

This paper examines the differences in school (NAPLAN) outcomes between New South Wales and Queensland. It shows that there are pronounced differences in Year 3 NAPLAN results between these states, though these dissipate when later class years are considered. The reasons for these state effects in school outcomes are explored using an empirical…

Analysing annual financial statements of public ordinary secondary schools in the Tshwane north district, South Africa

Directory of Open Access Journals (Sweden)

Frank Doussy

2015-08-01

Full Text Available This paper presents the results from an analysis of the annual financial statements of public ordinary secondary schools in the Tshwane North District, South Africa. The analysis was done to assess the quality of these annual financial statements as well as the apparent usefulness thereof for the parents of the learners in the school. These users are probably most concerned with the quality and usefulness of information presented to them for providing the necessary assurance that the funds received by the school are properly accounted for and used to the advantage of their children. The results suggest that assurance in this regard is lacking as audits are not done at all, or are of an extremely poor quality. The quality of the financial statements is also poor, with scant regard for Generally Accepted Accounting Practice or the South African Schools Act. Urgent intervention from the Education Departments is needed to ensure that the South African Schools Act is adhered to and that proper audits are conducted by suitably qualified accountants and auditors. The South African Institute for Chartered Accountants (SAICA should also play a more positive role in this regard by ensuring that audit practices are enforced and quality annual financial statements are presented

The Philosophical Genealogy of Taylor's Social Imaginaries: A Complex History of Ideas and Predecessors.

Science.gov (United States)

Vanheeswijck, Guido M

2017-01-01

The deepest sources of Charles Taylor's use of the concept "social imaginaries" are often related to political philosophy or social anthropology (Anderson, Castoriadis). The purpose of this article is to show that they also form part of Taylor's struggle to overcome the epistemological construal in modern philosophy and culture. Taylor locates the concept "social imaginaries" in the Kantian tradition, identifying their role to that of transcendental schemes. However, there remains a central difference between Kant's transcendental schemes and Taylor's social imaginaries. To elucidate that difference, this article will track the philosophical genealogy of Taylor's concept of "social imaginaries" in three steps.

Sexual harassment and violence in South African schools | Prinsloo ...

African Journals Online (AJOL)

After1994 several pieces of legislation were passed in South Africa to ensure equity in education and equal opportunities for all learners. Some shocking reports have indicated that sexual harassment of girls is a serious problem in many of our schools. These girls are denied equal opportunities and effective education in ...

Eco-Schools and the Quality of Education in South Africa: Realising ...

African Journals Online (AJOL)

Eco-Schools and the Quality of Education in South Africa: Realising the potential. ... Southern African Journal of Environmental Education. Journal Home · ABOUT THIS JOURNAL ... AJOL African Journals Online. HOW TO USE AJOL.

Probabilistic assessment of the rainwater harvesting potential of schools in South Africa

OpenAIRE

Ndiritu, J. G.; McCarthy, S.; Tshirangwana, N.

2014-01-01

In comparison to other sources of water supply, rainwater harvesting (RWH) has the typical advantages of being cheaper and easier to operate and maintain. This study aimed at assessing the hydrologic rainwater harvesting potential of rural schools in South Africa by obtaining RWH storage capacity (level of supply) reliability relationships of representative schools. Thirty-two schools located in three rural areas that have varied rainfall characteristics were selected for the analysis. For ea...

The quest for a culture of learning: a South African schools perspective

Directory of Open Access Journals (Sweden)

F H Weeks

2012-01-01

Full Text Available Within the media and the literature the need is often expressed for the establishment of a culture of learning within South African schools. The contrasting view tends to be one of dysfunctional schools that have come into being, giving rise to significant learner behaviour problems and poor pass rates being encountered in practice. This paper is directed at gaining conceptual clarity as to what is meant by a "culture of learning" and exploring two fundamentally different views as to how such a culture can be nurtured within South African schools. The study is based on a multidisciplinary literature review to gain an understanding of the concept and the theories advocated for bringing about a culture change. A key finding emanating from the study is that the traditional culture management approach advocated in the literature may not be all that effective in practice and that an alternative approach that views "culture of learning" as an emergent phenomenon that has its origins in the social interaction taking place within classrooms, schools and learning communities may be more effective.

Barriers to School-Family Collaboration at a School Located in an Informal Settlement in South Africa

Directory of Open Access Journals (Sweden)

Mavis Maria Raborife

2010-06-01

Full Text Available As the shift towards inclusive education intensifies, the need for school to work collaboratively with families becomes necessaryfor the sake of maximizing students’ academic success. However, in certain communities such effort is often undermined byvarious factors which interact directly and/or indirectly with both institutions – school and family. Schools located in informalsettlements of South Africa are not unique to this situation. This paper presents the perspectives of parents, educators andschool management teams about barriers which inhibit collaboration between the school and families. Interviews conducted ingroups and with individual participants were followed as data collection strategies. Findings revealed factors falling under threecategories, namely: community, schools and family factors. These factors interact with each other in a dynamic way to createchallenges to undermine school-family collaboration. The findings of this study could guide school efforts for promotingmeaningful and long-lasting relationships with families.

The Interpretation Of Metaphor Found In 20 Songs Of Taylor Swift

OpenAIRE

Desriani, Shella

2015-01-01

This paper entitled The interpretation of metaphor found in 20 of taylor swift. this paper discuss the types and meaning of metaphor in the lyrics of the song taylor swift. The purpose of this paper is to analyze types of metaphor in the form of simile, personification and hyperbole contained in the lyrics of the song taylor swift. In this paper the authors wrote the paper used the method of literature, collect some data from some books, and the internet. the lyric which contained metaphors i...

Rapid Calculation of Spacecraft Trajectories Using Efficient Taylor Series Integration

Science.gov (United States)

Scott, James R.; Martini, Michael C.

2011-01-01

A variable-order, variable-step Taylor series integration algorithm was implemented in NASA Glenn's SNAP (Spacecraft N-body Analysis Program) code. SNAP is a high-fidelity trajectory propagation program that can propagate the trajectory of a spacecraft about virtually any body in the solar system. The Taylor series algorithm's very high order accuracy and excellent stability properties lead to large reductions in computer time relative to the code's existing 8th order Runge-Kutta scheme. Head-to-head comparison on near-Earth, lunar, Mars, and Europa missions showed that Taylor series integration is 15.8 times faster than Runge- Kutta on average, and is more accurate. These speedups were obtained for calculations involving central body, other body, thrust, and drag forces. Similar speedups have been obtained for calculations that include J2 spherical harmonic for central body gravitation. The algorithm includes a step size selection method that directly calculates the step size and never requires a repeat step. High-order Taylor series integration algorithms have been shown to provide major reductions in computer time over conventional integration methods in numerous scientific applications. The objective here was to directly implement Taylor series integration in an existing trajectory analysis code and demonstrate that large reductions in computer time (order of magnitude) could be achieved while simultaneously maintaining high accuracy. This software greatly accelerates the calculation of spacecraft trajectories. At each time level, the spacecraft position, velocity, and mass are expanded in a high-order Taylor series whose coefficients are obtained through efficient differentiation arithmetic. This makes it possible to take very large time steps at minimal cost, resulting in large savings in computer time. The Taylor series algorithm is implemented primarily through three subroutines: (1) a driver routine that automatically introduces auxiliary variables and

Effective School-Community Relations as a Key Performance Indicator for the Secondary School Administrator in Aba South District, Nigeria

Science.gov (United States)

Abraham, Nath. M.; Ememe, Ogbonna N.

2012-01-01

This study investigates Effective School-Community Relations as a key Performance Indicator (KPI) of Secondary Schools Administrator in Aba South District, Nigeria. Descriptive survey method was adopted. All the 248 teachers made up the population and sample in a purposive sampling technique representing 100% of the entire population as sample. A…

Bubble behavior in a vertical Taylor-Couette flow

International Nuclear Information System (INIS)

Murai, Y; Oiwa, H; Takeda, Y

2005-01-01

Bubble distributions organized in a vertical Taylor-Couette flow are experimentally investigated. Modification of shear stress due to bubbles is measured with a torque sensor installed on the rotating inner cylinder. The wall shear stress decreases as bubbles are injected in all the tested range of Re from 600 to 4500. The drag reduction ratio per void fraction measured in the present experiment, which indicates net gain of the drag reduction, has been evaluated. The gain was more than unity for Re 4000. The maximum gain achieved was around 10 at Re = 600, at which point the bubbles dispersed widely on the inner cylinder surface and effectively restrict momentum exchange of fluid between the two walls. The expansion of Taylor vortices in the vertical direction by the presence of bubbles was confirmed by flow visualization including particle tracking velocimetry. Such bubble behaviours interacting with Taylor vortices are discussed in detail in this paper

Primary school teachers’ opinions and attitudes towards stuttering in two South African urban education districts

OpenAIRE

Kristen Abrahams; Michal Harty; Kenneth O. St. Louis; Lehana Thabane; Harsha Kathard

2016-01-01

Background: As teachers form an important part of the intervention process with childrenwho stutter in primary school, the primary aim was to describe primary school teachers’attitudes in South Africa. The secondary aim was to compare teachers’ attitudes towardsstuttering in South Africa with those from a pooled group of respondents in the Public OpinionSurvey of Human Attributes–Stuttering (POSHA-S) database from different countries collectedin 2009–2014. Method: A quantitative, cross-sec...

Adolescent Weight Status and Self-Reported School Performance in South Korea

Directory of Open Access Journals (Sweden)

Young Kyung Do

2011-01-01

Full Text Available Using a nationally representative sample of 142 783 middle school (13–15 years old and high school (16–18 years old students in South Korea, this study examined whether (1 overweight and obesity are more likely to be associated with lower self-reported school performance; (2 overweight and obese students are more likely to enrol in a vocational high school as opposed to a general high school; (3 the association between obesity and poorer self-reported school performance is mediated through body image stress and health status. We found that excess weight was negatively associated with self-reported school performance among middle and general high school students, and that obese students had a higher probability of being enrolled in a vocational over a general high school. We did not find strong evidence on the mediating role of body image stress and health status.

Photonic arbitrary waveform generator based on Taylor synthesis method

DEFF Research Database (Denmark)

Liao, Shasha; Ding, Yunhong; Dong, Jianji

2016-01-01

Arbitrary waveform generation has been widely used in optical communication, radar system and many other applications. We propose and experimentally demonstrate a silicon-on-insulator (SOI) on chip optical arbitrary waveform generator, which is based on Taylor synthesis method. In our scheme......, a Gaussian pulse is launched to some cascaded microrings to obtain first-, second- and third-order differentiations. By controlling amplitude and phase of the initial pulse and successive differentiations, we can realize an arbitrary waveform generator according to Taylor expansion. We obtain several typical...... waveforms such as square waveform, triangular waveform, flat-top waveform, sawtooth waveform, Gaussian waveform and so on. Unlike other schemes based on Fourier synthesis or frequency-to-time mapping, our scheme is based on Taylor synthesis method. Our scheme does not require any spectral disperser or large...

Early numeracy performance of South African school beginners

Directory of Open Access Journals (Sweden)

Pirjo Aunio

2016-12-01

Full Text Available Early numeracy skills are highly relevant for children’s mathematics learning at school, especially in the initial years when much mathematics learning relies on early numeracy competence. The aim of this study was to investigate the level of early numeracy skills in a sample of South African children in the first months of formal schooling. In this cross- sectional study, there were 443 first graders (206 girls and 237 boys from Gauteng Province schools. The mean age of the children was 81.61 months (6 years 10 months (SD 5.40 months. Their early numeracy skills were measured with the ThinkMath Scale. The main finding of this study was that there were statistically significant differences in early numeracy skills between the children when they started first grade. The differences were related to the home language of the first graders in the English medium schools, as well as the type of school (public vs. private. This article concludes that the numeracy competence of the children from the sample was notably varied in the beginning of their formal schooling, which has implications for teaching in the vastly different classroom populations that are all served by one national curriculum.

Schoolchildren affected by HIV in rural South Africa: Schools as ...

African Journals Online (AJOL)

This article explores how schoolchildren made vulnerable due to HIV and AIDS might cope and even thrive in a rural school environment in South Africa. I argue that ... Keywords: appreciative inquiry, assets, coping, PhotoVoice, psychosocial aspects, research methods, rural settings, visual participatory methods

Framing of school violence in the South African printed media ...

African Journals Online (AJOL)

... largely unnoticed by journalists. I argue that the main frames provided to readers in South African newspapers fail largely to elicit social responsibility, while at the same time promoting civic indifference. Keywords: emotional violence; media framing; physical violence; school violence; sexual violence; social responsibility ...

Taylor Hydro plant goes live

International Nuclear Information System (INIS)

Anon.

2000-01-01

The 12.75 MW Taylor Hydroelectric Plant in Magrath, Alberta, synchronized its generator with the Alberta Power Grid and began production in April 2000. The plant is located on Government of Alberta irrigation works and is owned by Canadian Hydro Developers. During the irrigation season the plant will generate approximately 40 million kilowatt hours of zero-emission 'green' power for consumption, enough to power 5,000 homes for a year. The Taylor plant is a joint venture with EPCOR Power Development Corporation, a wholly-owned subsidiary of EPCOR Inc., the City of Edmonton utility. Canadian Hydro Developers also owns a 19 MW wind plant and a 6 MW gas plant in Alberta and five other 'run of river' hydro plants in Ontario and British Columbia. The company is committed to the concept of low-impact power generation; its ownership of wind run-of-river hydro and gas-fired facilities is proof of that commitment

Micromixer based on Taylor dispersion

International Nuclear Information System (INIS)

Yang, H; Nguyen, N-T; Huang, X

2006-01-01

This paper reports an analytical model, the fabrication and the characterization of a polymeric micromixer based on Taylor dispersion. Due to the distributed velocity field over the channel cross section, the effective dispersion in axial direction in a microchannel is much stronger than the pure molecular diffusion. In our work, squential segmentation was used in the micromixer for improving mixing in a microchannel. The micromixer was designed and fabricated based on lamination of five 100-μm-thick polymer sheets. Rubber valve seats were embedded between the forth and the fifth layers. The polymer layers were machined using a CO 2 laser. The lamination of the five layers was carried out by a commercial hot laminator (Aurora LM-450HC). External solenoid actuators are used for closing the valves at the mixer inlets. The experimental results confirm the effect of Taylor dispersion. Mixing ratio can be adjusted by pulse width modulation of the control signal of the solenoids

Numerical simulation of Rayleigh-Taylor turbulent mixing layers

International Nuclear Information System (INIS)

Poujade, O.; Lardjane, N.; Peybernes, M.; Boulet, M.

2009-01-01

Accelerations in actual Rayleigh-Taylor instabilities are often variable. This article focuses on a particular class of variable accelerations where g(t) ∝ t n . A reference database is built from high resolution hydrodynamic numerical simulations. The successful comparison with a simple OD analytical model and the statistical 2SFK (2-Structure, 2-Fluid, 2-Turbulence) turbulence model is provided. Moreover, we show the difference between the mechanism at play in the Rayleigh-Taylor turbulent mixing zone and Kolmogorov's in the self similar developed turbulent regime. (authors)

Hearing loss in urban South African school children (grade 1 to 3).

Science.gov (United States)

Mahomed-Asmail, Faheema; Swanepoel, De Wet; Eikelboom, Robert H

2016-05-01

This study aimed to describe the prevalence and characteristics of hearing loss in school-aged children in an urban South African population. Children from grade one to three from five schools in the Gauteng Province of South Africa formed a representative sample for this study. All children underwent otoscopic examinations, tympanometry and pure tone screening (25dB HL at 1, 2 and 4kHz). Children who failed the screening test and 5% of those who passed the screening test underwent diagnostic audiometry. A total of 1070 children were screened. Otoscopic examinations revealed that a total of 6.6% ears had cerumen and 7.5% of ears presented with a type-B tympanogram. 24 children (12 male, 12 female) were diagnosed with hearing loss. The overall prevalence of hearing loss was 2.2% with Caucasian children being 2.9 times more (95% confidence interval, 1.2-6.9) likely to have a hearing loss than African children. Hearing loss prevalence in urban South African school-aged children suggest that many children (2.2%) are in need of some form of follow-up services, most for medical intervention (1.2%) with a smaller population requiring audiological intervention (0.4%). Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Reconnaissance surficial geologic map of the Taylor Mountains quadrangle, southwestern Alaska

Science.gov (United States)

Wilson, Frederic H.

2015-09-28

This map and accompanying digital files are the result of the interpretation of aerial photographs from the 1950s as well as more modern imagery. The area, long considered a part of Alaska that was largely not glaciated (see Karlstrom, 1964; Coulter and others, 1965; or Péwé, 1975), actually has a long history reflecting local and more distant glaciations. An unpublished photogeologic map of the Taylor Mountains quadrangle from the 1950s by J.N. Platt Jr. was useful in the construction of this map. Limited new field mapping in the area was conducted as part of a mapping project in the Dillingham quadrangle to the south (Wilson and others, 2003); however, extensive aerial photograph interpretation represents the bulk of the mapping effort. The accompanying digital files show the sources for each line and geologic unit shown on the map.

Towards finite density QCD with Taylor expansions

International Nuclear Information System (INIS)

Karsch, F.; Schaefer, B.-J.; Wagner, M.; Wambach, J.

2011-01-01

Convergence properties of Taylor expansions of observables, which are also used in lattice QCD calculations at non-zero chemical potential, are analyzed in an effective N f =2+1 flavor Polyakov quark-meson model. A recently developed algorithmic technique allows the calculation of higher-order Taylor expansion coefficients in functional approaches. This novel technique is for the first time applied to an effective N f =2+1 flavor Polyakov quark-meson model and the findings are compared with the full model solution at finite densities. The results are used to discuss prospects for locating the QCD phase boundary and a possible critical endpoint in the phase diagram.

Effects of Auricular Acupressure Therapy on Primary Dysmenorrhea for Female High School Students in South Korea.

Science.gov (United States)

Cha, Nam Hyun; Sok, Sohyune R

2016-09-01

To examine the effect of auricular acupressure therapy on primary dysmenorrhea among female high school students in South Korea. A randomized controlled trial was employed. The study sample consisted of 91 female high school students, with 45 participants in the experimental group and 46 in the control group in two regions of South Korea. The average age of the participants was 16.7 years, and the average age of menarche was 12.2 years. Auricular acupressure therapy including an auricular acupressure needle on skin paper tape was applied on an ear for 3 days during periods of extreme primary dysmenorrhea. The acupoint names were Jagung, Sinmun, Gyogam, and Naebunbi. For the placebo control group, only the skin paper tape without an auricular acupressure needle was applied on the same acupoints. Measures used were the Menstrual Distress Questionnaire to assess primary dysmenorrhea, and the visual analog scale to assess abdominal and back pain of participants. There were significant differences on abdominal pain (t = 24.594, p dysmenorrhea (t = 32.187, p dysmenorrhea of female high school students in South Korea. Auricular acupressure therapy was an effective intervention for alleviating abdominal pain, back pain, and primary dysmenorrhea of female high school students in South Korea. For feasibility of the auricular acupressure therapy in practice, it is needed to train and learn the exact positions of acupoints in ear. Health providers should consider providing auricular acupressure therapy as an alternative method for reducing abdominal and back pain, and primary dysmenorrhea in female high school students in South Korea. © 2016 Sigma Theta Tau International.

Growing a cyber-safety culture amongst school learners in South Africa through gaming

Directory of Open Access Journals (Sweden)

Elmarie Kritzinger

2017-10-01

Full Text Available Virtually all school learners today have access to ICT devices and the internet at home or at school. More and more schools are using ICT devices to improve education in South Africa. ICT devices and internet access have enormous advantages and assist learners in learning and teachers in teaching more successfully. However, with these advantages come numerous ICT and cyber-risks and threats that can harm learners, for example cyber-bullying, identity theft and access to inappropriate material. Currently, South Africa does not have a long-term plan to grow a cyber-safety culture in its schools. This research therefore proposes a short-term initiative in the form of a game-based approach, which will assist school learners in becoming more cyber safe and teach learners about the relevant cyber-related risks and threats. The research is based on a quantitative survey that was conducted among primary school learners to establish if the game-based approach would be a feasible short-term initiative. The aim of the research is to establish if a game based approach can be used to improve cyber-safety awareness. This approach was plotted into the required ICT and cyber-safety policy required by all schools.

The High Cost of South Carolina's Low Graduation Rate. School Choice Issues in the State

Science.gov (United States)

Gottlob, Brian J.

2007-01-01

Research has documented a crisis in South Carolina's high school graduation rate. While state officials report a graduation rate above 70 percent, researchers from South Carolina and elsewhere place the rate just above 50 percent, with rates among minority students lower than 50 percent. South Carolina's graduation rate is the worst of all 50…

Educators' Disciplinary Capabilities after the Banning of Corporal Punishment in South African Schools

Science.gov (United States)

Maphosa, Cosmas; Shumba, Almon

2010-01-01

The escalation of learner indiscipline cases in schools suggests failure by teachers to institute adequate alternative disciplinary measures after corporal punishment was outlawed in South African schools. We sought to address the following two research questions: (a) How do educators view their disciplinary capabilities in the post-corporal…

Referral criteria for school-based hearing screening in South Africa ...

African Journals Online (AJOL)

Referral criteria for school-based hearing screening in South Africa: Considerations for resource-limited contexts. ... Diagnostic audiometry confirmed that almost half (47%) of the referred children had a hearing loss. Conclusion: A screening intensity of 25 dB HL andimmediate rescreen reduces the referral rate significantly ...

Equity in Science at South African Schools: A pious platitude or an achievable goal?

Science.gov (United States)

Dewnarain Ramnarain, Umesh

2011-07-01

The apartheid policies in South Africa had a marked influence on the accessibility and quality of school science experienced by the different race groups. African learners in particular were seriously disadvantaged in this regard. The issues of equity and redress were foremost in transformation of the education system, and the accompanying curriculum reform. This paper reports on equity in terms of equality of outputs and equality of inputs in South African school science, with a particular focus on the implementation of practical science investigations. This was a qualitative case study of two teachers on their implementation of science investigations at two schools, one a township school, previously designated for black children, and the other a former Model C school, previously reserved for white children. My study was guided by the curriculum implementation framework by Rogan and Grayson in trying to understand the practice of these teachers at schools located in contextually diverse communities. The framework helped profile the implementation of science investigations and also enabled me to explore the factors which are able to support or hinder this implementation.

From Little Rock Central High School to Laerskool Potgitersrus: Education and Racial Change in the United States and South Africa

OpenAIRE

Catsam, Derek

2007-01-01

In both South Africa and the United States South, education stands and has stood historically as a vital cultural and economic center for its people. In both cases school integration has proved to be profoundly contentious. Certainly much of the Civil Rights Movement in the U.S. was centered on integrating schools from the elementary school playground to the university campus. An interesting and important parallel between South Africa's segregationists and those in America also emerged in the...

Validity and reliability of the South African health promoting schools monitoring questionnaire.

Science.gov (United States)

Struthers, Patricia; Wegner, Lisa; de Koker, Petra; Lerebo, Wondwossen; Blignaut, Renette J

2017-04-01

Health promoting schools, as conceptualised by the World Health Organisation, have been developed in many countries to facilitate the health-education link. In 1994, the concept of health promoting schools was introduced in South Africa. In the process of becoming a health promoting school, it is important for schools to monitor and evaluate changes and developments taking place. The Health Promoting Schools (HPS) Monitoring Questionnaire was developed to obtain opinions of students about their school as a health promoting school. It comprises 138 questions in seven sections: socio-demographic information; General health promotion programmes; health related Skills and knowledge; Policies; Environment; Community-school links; and support Services. This paper reports on the reliability and face validity of the HPS Monitoring Questionnaire. Seven experts reviewed the questionnaire and agreed that it has satisfactory face validity. A test-retest reliability study was conducted with 83 students in three high schools in Cape Town, South Africa. The kappa-coefficients demonstrate mostly fair (κ-scores between 0.21 and 0.4) to moderate (κ-scores between 0.41 and 0.6) agreement between test-retest General and Environment items; poor (κ-scores up to 0.2) agreement between Skills and Community test-retest items, fair agreement between Policies items, and for most of the questions focussing on Services a fair agreement was found. The study is a first effort at providing a tool that may be used to monitor and evaluate students' opinions about changes in health promoting schools. Although the HPS Monitoring Questionnaire has face validity, the results of the reliability testing were inconclusive. Further research is warranted. © The Author 2016. Published by Oxford University Press.

Relationships between the School-Level and Classroom-Level Environment in Secondary Schools in South Africa

Science.gov (United States)

Aldridge, Jill M.; Fraser, Barry J.; Laugksch, Rüdiger C.

2011-01-01

We report research into associations between the school-level and classroom-level environment in science classrooms in South Africa. An instrument, developed to assess students' perceptions of their classroom learning environment as a means of monitoring and guiding changes towards outcomes-based education, was administered to 2,638 Grade 8…

Stability of an expanding cylindrical plasma envelope: Rayleigh--Taylor instability

International Nuclear Information System (INIS)

Han, S.J.

1982-01-01

The stability of a cylindrically symmetric plasma envelope driven outward by blast waves is considered. The plasma fluid is assumed to be a compressible, isentropic gas describable as an ideal gas ( p = arho/sup γ/, γ>1). The stability problem of such an envelope undergoing self-similar motion is solved by considering the initial-value problem. It is shown that in the early phase of an expansion, the envelope is unstable to Rayleigh--Taylor modes which develop at the inner surface. In the later phase of the expansion, the Rayleigh--Taylor modes are weakened due to the geometrical divergence effect. The implications of the time-dependent behavior of the Rayleigh--Taylor instability for plasma switches are discussed

Internal Whole-School Evaluation in South Africa: The Influence of Holistic Staff Capacity

Science.gov (United States)

Govender, Neelan; Grobler, Bennie; Mestry, Raj

2016-01-01

The Holistic Equilibrium Theory of Organizational Development was used to gain an in-depth understanding of the influence of holistic staff capacity on conducting effective internal whole-school evaluation (IWSE) within the Gauteng Department of Education's public secondary schools. In the context of South African education, the staff of each…

Sleep Habits of Elementary and Middle School Children in South Texas

OpenAIRE

Surani, Salim; Hesselbacher, Sean; Surani, Saherish; Sadasiva, Sreevidya; Surani, Zoya; Surani, Sara S.; Khimani, Amina; Subramanian, Shyam

2015-01-01

Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of el...

Primary school teachers' opinions and attitudes towards stuttering in two South African urban education districts.

Science.gov (United States)

Abrahams, Kristen; Harty, Michal; St Louis, Kenneth O; Thabane, Lehana; Kathard, Harsha

2016-07-27

As teachers form an important part of the intervention process with childrenwho stutter in primary school, the primary aim was to describe primary school teachers'attitudes in South Africa. The secondary aim was to compare teachers' attitudes towardsstuttering in South Africa with those from a pooled group of respondents in the Public OpinionSurvey of Human Attributes-Stuttering (POSHA-S) database from different countries collectedin 2009-2014. A quantitative, cross-sectional survey research design was used. Primary schools intwo education districts in Western Cape, South Africa, were sampled. The POSHA-S, a selfadministeredquestionnaire, was completed by a cluster sample of 469 participants. Overall positive attitudes towards stuttering were found, specifically related to thepotential of people who stutter, although the result should be interpreted with caution as thesample was not homogenously positive. Teachers still had misconceptions about personalitystereotypes and the cause of stuttering. The attitudes of the South African sample were slightlymore positive compared with the samples in the current POSHA-S database. When developing stuttering intervention strategies, there are a number of keyconsiderations to take into account. The study provides a basis for speech-language therapiststo think about intervention with teachers and which areas of stuttering to consider.

Fluctuation scaling, Taylor's law, and crime.

Directory of Open Access Journals (Sweden)

Quentin S Hanley

Full Text Available Fluctuation scaling relationships have been observed in a wide range of processes ranging from internet router traffic to measles cases. Taylor's law is one such scaling relationship and has been widely applied in ecology to understand communities including trees, birds, human populations, and insects. We show that monthly crime reports in the UK show complex fluctuation scaling which can be approximated by Taylor's law relationships corresponding to local policing neighborhoods and larger regional and countrywide scales. Regression models applied to local scale data from Derbyshire and Nottinghamshire found that different categories of crime exhibited different scaling exponents with no significant difference between the two regions. On this scale, violence reports were close to a Poisson distribution (α = 1.057 ± 0.026 while burglary exhibited a greater exponent (α = 1.292 ± 0.029 indicative of temporal clustering. These two regions exhibited significantly different pre-exponential factors for the categories of anti-social behavior and burglary indicating that local variations in crime reports can be assessed using fluctuation scaling methods. At regional and countrywide scales, all categories exhibited scaling behavior indicative of temporal clustering evidenced by Taylor's law exponents from 1.43 ± 0.12 (Drugs to 2.094 ± 0081 (Other Crimes. Investigating crime behavior via fluctuation scaling gives insight beyond that of raw numbers and is unique in reporting on all processes contributing to the observed variance and is either robust to or exhibits signs of many types of data manipulation.

Fluctuation scaling, Taylor's law, and crime.

Science.gov (United States)

Hanley, Quentin S; Khatun, Suniya; Yosef, Amal; Dyer, Rachel-May

2014-01-01

Fluctuation scaling relationships have been observed in a wide range of processes ranging from internet router traffic to measles cases. Taylor's law is one such scaling relationship and has been widely applied in ecology to understand communities including trees, birds, human populations, and insects. We show that monthly crime reports in the UK show complex fluctuation scaling which can be approximated by Taylor's law relationships corresponding to local policing neighborhoods and larger regional and countrywide scales. Regression models applied to local scale data from Derbyshire and Nottinghamshire found that different categories of crime exhibited different scaling exponents with no significant difference between the two regions. On this scale, violence reports were close to a Poisson distribution (α = 1.057 ± 0.026) while burglary exhibited a greater exponent (α = 1.292 ± 0.029) indicative of temporal clustering. These two regions exhibited significantly different pre-exponential factors for the categories of anti-social behavior and burglary indicating that local variations in crime reports can be assessed using fluctuation scaling methods. At regional and countrywide scales, all categories exhibited scaling behavior indicative of temporal clustering evidenced by Taylor's law exponents from 1.43 ± 0.12 (Drugs) to 2.094 ± 0081 (Other Crimes). Investigating crime behavior via fluctuation scaling gives insight beyond that of raw numbers and is unique in reporting on all processes contributing to the observed variance and is either robust to or exhibits signs of many types of data manipulation.

Principals' Leadership Skills and School Effectiveness: The Case of South Western Nigeria

Science.gov (United States)

Bolanle, Akinola Oluwatoyin

2013-01-01

The study sought to find out the leadership skills possessed by Principals of public secondary schools in south western Nigeria and the relationship between these leadership skills and school effectiveness in terms of student academic achievement. The descriptive survey research design was employed for the study. 154 Principals and 770 teachers,…

Atomic Power | Taylor | Zede Journal

African Journals Online (AJOL)

Zede Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3 (1968) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Atomic Power. D Taylor. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT ...

Gender Factors Associated with Sexual Abstinent Behaviour of Rural South African High School Going Youth in KwaZulu-Natal, South Africa

Science.gov (United States)

Dlamini, Siyabonga; Taylor, Myra; Mkhize, Nosipho; Huver, Rosemarie; Sathiparsad, Reshma; de Vries, Hein; Naidoo, Kala; Jinabhai, Champak

2009-01-01

The cross-sectional study investigated South African rural high school learners' choice of sexual abstinence in order to be able to develop tailored health education messages. All Grade 9 learners from one class at each of 10 randomly selected rural high schools participated. The Integrated Model for Motivational and Behavioural Change was used to…

Rayleigh-Taylor instability of cylindrical jets with radial motion

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiang M. [GE Nuclear, Wilmington, NC (United States); Schrock, V.E.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States)

1995-09-01

Rayleigh-Taylor instability of an interface between fluids with different densities subjected to accelleration normal to itself has interested researchers for almost a century. The classic analyses of a flat interface by Rayleigh and Taylor have shown that this type of instability depends on the direction of acceleration and the density differences of the two fluids. Plesset later analyzed the stability of a spherically symmetric flows (and a spherical interface) and concluded that the instability also depends on the velocity of the interface as well as the direction and magnitude of radial acceleration. The instability induced by radial motion in cylindrical systems seems to have been neglected by previous researchers. This paper analyzes the Rayleigh-Taylor type of the spherical case, the radial velocity also plays an important role. As an application, the example of a liquid jet surface in an Inertial Confinement Fusion (ICF) reactor design is analyzed.

Report on Action Research: An Analysis of the Effects of Selected Instructional Strategies on Student Achievement at Terre Haute South Vigo High School

Science.gov (United States)

Haystead, Mark W.

2010-01-01

This report describes the findings of an analysis of a series of action research projects conducted by Vigo County School Corporation at Terre Haute South Vigo High School (hereinafter referred to as South Vigo). During the 2009-2010 school year, 20 teachers at South Vigo participated in independent action research studies regarding the extent to…

The Drakensberg Escarpment as the great supplier of water to South Africa

CSIR Research Space (South Africa)

Taylor, SJ

2016-11-01

Full Text Available : Investigations of the Hydrologic Cycle in Alpine Environments: 1-41 The Drakensberg Escarpment as the great supplier of water to South Africa Taylor, SJ Ferguson, JHW Engelbrecht, Francois A Clark, VR Van Rensburg, S Barker, N ABSTRACT...

TEACHING THE VIOLENT PAST IN SECONDARY SCHOOLS IN NEWLY INDEPENDENT SOUTH SUDAN

Directory of Open Access Journals (Sweden)

Merethe Skårås

2016-12-01

Full Text Available This article analyses the teaching and learning of South Sudan history from 1955–2005 in secondary schools in South Sudan with a specific focus on national unity. The article draws on two periods of focused ethnography, from September to December 2014 and July to September 2015, including classroom observation and interviews with teachers, student teachers and students in two geographical locations. Additionally, 69 written essays from secondary school students of History have been analysed in order to get an insight into their knowledge of the recent violent past. The use of classroom video observation makes a significant contribution to the field as most studies focus on documents and textbooks. The analysis focuses on national unity and uses theories of collective memory and attribution to examine the narratives of the past. The article argues that the national narrative of South Sudan is still closely tied to enemy images of the former enemy of Sudan in the north, while internal ethnic tensions are suppressed and excluded from the official national narrative taught in the classroom.

Incentives to Exclude: The Political Economy Constraining School Fee Abolition in South Africa

Science.gov (United States)

Nordstrum, Lee E.

2012-01-01

In 2009, the South African Department of Education extended tuition fee abolition to schools serving the poorest 60% of students, increased from 40% in 2007. This policy intends to increase access to and longevity in school for the poorest households by removing fees as a barrier and replacing private revenue with increased state funds. Despite…

Towards Human Rights in South African Schools: An Agenda for Research and Practice.

Science.gov (United States)

Kruss, Glenda

2001-01-01

Develops a taxonomy of four kinds of situations in which race and other grounds for discrimination become the focus of school-level controversy surrounding equality and equity. Examines the kinds of responses and discourses South African schools use to engage with the policy discourse of desegregation and human rights and establishes an agenda for…

Sleep Habits of Elementary and Middle School Children in South Texas.

Science.gov (United States)

Surani, Salim; Hesselbacher, Sean; Surani, Saherish; Sadasiva, Sreevidya; Surani, Zoya; Surani, Sara S; Khimani, Amina; Subramanian, Shyam

2015-01-01

Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of elementary and middle school students, using the Children's Sleep Habit Questionnaire-Sleep Self-Report Form, which assessed the domains of bedtime resistance, sleep onset delay, sleep anxiety, sleep duration, night awakening, and daytime sleepiness. Results. The survey was completed by 499 elementary and 1008 middle school children. Trouble sleeping was reported by 43% in elementary school, compared with 29% of middle school children. Fifty percent of middle school children did not like sleeping, compared with 26% in elementary school. Bedtime resistance, sleep onset delay, and nighttime awakening were more common among elementary school students. Daytime sleepiness was more common among the middle school children when compared to elementary school children. Conclusions. Sleep abnormalities are present in elementary school children with changes in sleep habits into middle school.

The Impact of Regional Differences on Elementary School Teachers’ Attitudes Towards Their Students’ Use of Code Switching in a South Texas School District

Directory of Open Access Journals (Sweden)

Guadalupe Nancy Nava Gómez

2012-01-01

Full Text Available This study focused on investigating whether the teachers' geographical distribution influences their attitudes towards their students' use of code switching. The study was guided by the following research question: Are there differences between teachers' opinions of the north elementary schools and teachers' opinions of the south elementary schools, which are predominantly Hispanic, towards their students' use of code switching? If so, why? A twenty-item structured survey was utilized. The population consisted of 279 elementary school teachers at seven Northern and seven Southern schools in the same South Texas region. The data were analyzed with descriptive statistics. Findings showed that Southern teachers had more prejudices towards code switching than those from the North, who were more receptive to this socio-cultural and linguistic phenomenon due to the ethnic makeup of their classrooms.

South Dakota Middle School Mathematics Teachers' Perceptions of Teaching Competencies

Science.gov (United States)

Bleecker, Heather A.

2017-01-01

This quantitative research study investigates South Dakota middle school (grades 5-8) mathematics teachers' perceptions of teaching competencies including general pedagogical knowledge (GPK) and mathematical pedagogical content knowledge (MPCK). The study also considered how teacher characteristics relate to teacher competencies. The study…

Learners' self-reports of exposure to violence in South African schools

African Journals Online (AJOL)

opperwjj

The high levels of violence in South African and other communities have ... the widespread violence in the school context is an area of concern, because it impacts on .... in delinquency based on the power play going on in the family structure, ...

The Development Needs of Newly Appointed Senior School Leaders in the Western Cape South Africa: A Case Study

Directory of Open Access Journals (Sweden)

Nelius Jansen van Vuuren

2017-12-01

Full Text Available The essential role that senior school leaders play in school leadership teams to ensure effective strategic leadership in schools has been the subject of intense discussion for many years. Crucial to this debate is the establishment of professional learning and leadership approaches for newly appointed senior school leaders. Recommendations for policy and practice highlight the importance of appropriate, multifaceted, developmental support initiatives for newly appointed school leaders. In many countries, including South Africa, a teaching qualification and, in most cases, extensive teaching experience is the only requirement for being appointed as a senior school leader in a school. This tends to suggest that no further professional development is required for newly appointed school leaders, the problem addressed in this paper. This paper reports on the main findings of the perceived development needs of newly appointed senior school leaders in the Western Cape, South Africa, and suggests that school leaders occupy a unique and specialist role in education, which requires relevant and specific preparation to support effective leadership. The respondents of this study report a lack of contextualised training and support before and after their appointment in their new roles creating unique development needs. This paper, therefore, employs a mixed-method approach to gather data to understand the perceived needs of twenty newly appointed senior school leaders in the Western Cape, South Africa.

Desegregation in a Former "Whites Only" School in South Africa

Science.gov (United States)

Grootboom, Nomalanga P.

2012-01-01

After decades of racially segregated education under apartheid in South Africa, the process of school desegregation commenced in 1990's with the view equalize education for all, and fostering better relationships and making available equal opportunities for all learners. The process of desegregation not has been without problems as it is apparent…

Factors affecting aggression in South Korean middle school students.

Science.gov (United States)

Park, MiJeong; Choi, Jihea; Lim, Seung-Joo

2014-12-01

The study was undertaken to assess levels of aggression, and to determine factors affecting aggression among South Korean middle school students. A descriptive study was conducted using self-report questionnaires. The participants were 340 girls and boys from two middle schools and 302 questionnaires were used for the final data analysis. Aggression, academic stress, depression, self esteem, decision-making competency, and happiness were measured. Data were analyzed using descriptive statistics including t tests, one-way analysis of variance, Pearson's correlation coefficients and multiple regressions. Aggression had significant correlations with academic stress (r = .21, p decision-making competency (r = -.25, p emotional factors like depression and academic stress. Additionally, development of positive factors such as self esteem, decision-making skills, and happiness in middle school students is important to reduce aggression. Copyright © 2014. Published by Elsevier B.V.

Repainting, modifying, smashing Taylorism

OpenAIRE

Pruijt, Hans

2000-01-01

textabstractAbstract Survey data show that post-Tayloristic production concepts are not developing to the extent that many researchers had originally expected. It also is inadequate to portray post-Taylorism as a development that is happening, but just slower than expected. This is inadequate because there are counter-tendencies: the resurgence of the assembly line in the highly paradigmatic automobile assembly; the rise of the McDonalds-type organization; and continuing skills-replacing auto...

Financial statements and the discharging of financial accountability of ordinary public schools in South Africa

Directory of Open Access Journals (Sweden)

Frank Doussy

2014-10-01

Full Text Available The Schools Act, 84 of 1996 (section 42(b, requires that all public schools in South Africa, “as soon as practical, but not later than three months after the end of each financial year, draw up annual financial statements”. These schools must further submit audited financial statements to the Department of Education within six months after the school’s year end (section 43 and according to section 43(6, “at the request of an interested person, the governing body must make the records referred to in section 42, and the audited or examined financial statements referred to in this section, available for inspection”. The compilation, auditing and submission of these statements are therefore legally required and are compulsory for all schools. The study aims firstly to establish whether schools in South Africa comply with the current legislative prescripts and accounting and auditing practices, and secondly to identify possible problem areas in this regard.

Rayleigh-Taylor instability of cylindrical jets with radial motion

International Nuclear Information System (INIS)

Chen, X.M.; Schrock, V.E.; Peterson, P.F.

1997-01-01

Rayleigh-Taylor instability of an interface between fluids with different densities subjected to acceleration normal to itself has interested researchers for almost a century. The classic analyses of a flat interface by Rayleigh and Taylor have shown that this type of instability depends on the direction of acceleration and the density differences of the two fluids. Plesset later analyzed the stability of a spherically symmetric flows (and a spherical interface) and concluded that the instability also depends on the velocity of the interface as well as the direction and magnitude of radial acceleration. The instability induced by radial motion in cylindrical systems seems to have been neglected by previous researchers. This paper analyzes the Rayleigh-Taylor type of instability for a cylindrical surface with radial motions. The results of the analysis show that, like the spherical case, the radial velocity also plays an important role. As an application, the example of a liquid jet surface in an Inertial Confinement Fusion (ICF) reactor design is analyzed. (orig.)

Dynamic stabilization of the imploding-shell Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Boris, J.P.

1977-01-01

A method for dynamic stabilization of the Rayleigh-Taylor (R-T) instability on the surface of an imploding fusion pellet is discussed. The driving laser beams are modulated in intensity so the ablation layer is subject to a rapidly and strongly oscillating acceleration. A substantial band of the Rayleigh-Taylor instability spectrum can be stabilized by this oscillation even though the time average acceleration vector lies in the destabilizing direction. By adjusting the frequency, structure, and amplitude of the modulation, the band of dynamically stabilized modes can be made to include the most unstable and dangerous modes. Thus considerably higher aspect ratio shells (i.e., thinner shells) could implode successfully than had been previously considered stable enough. Both theory and numerical simulations support this conclusion for the case of laser-driven pellet implosions. Similar modulation via transverse beam oscillations or parallel bunching should also work to stabilize the most dangerous surface Rayleigh-Taylor modes in relativistic electron-, ion- and heavy ion-pellet fusion schemes. (U.K.)

The right versus the good? On the right in the Philosophy of Charles Taylor

Directory of Open Access Journals (Sweden)

Javier García Caladín

2013-05-01

Full Text Available The aim of this article is to analyze the famous confrontation between the right and the good. We start with the analysis of Charles Taylor about the different significances of the good and his criticism to a procedural and restrictive approach of the moral (such as Habermas and Kymlicka. Secondly, we review in depth the ethics of Taylor and we stress the vague remark of «the just» in the use of Taylor. Finally, we evaluate the deontological deficiencies of the ethics of Taylor and try to find other ways to complement it.

An Application of Taylor Models to the Nakao Method on ODEs

OpenAIRE

Yamamoto, Nobito; Komori, Takashi

2009-01-01

The authors give short survey on validated computaion of initial value problems for ODEs especially Taylor model methods. Then they propose an application of Taylor models to the Nakao method which has been developed for numerical verification methods on PDEs and apply it to initial value problems for ODEs with some numerical experiments.

Growing a cyber-safety culture amongst school learners in South Africa through gaming

OpenAIRE

Elmarie Kritzinger

2017-01-01

Virtually all school learners today have access to ICT devices and the internet at home or at school. More and more schools are using ICT devices to improve education in South Africa. ICT devices and internet access have enormous advantages and assist learners in learning and teachers in teaching more successfully. However, with these advantages come numerous ICT and cyber-risks and threats that can harm learners, for example cyber-bullying, identity theft and access to inappropriate material...

Expressing the remainder of the Taylor polynomial when the function lacks smoothness

Czech Academy of Sciences Publication Activity Database

Hošek, Radim

2017-01-01

Roč. 72, č. 3 (2017), s. 126-130 ISSN 0013-6018 Institutional support: RVO:67985840 Keywords : Taylor polynomial * Taylor theorem Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics http://www.ems-ph.org/doi/10.4171/EM/335

Development and Examination of an Alternative School Performance Index in South Carolina. REL 2015-097

Science.gov (United States)

Koon, Sharon; Petscher, Yaacov; Hughes, John

2015-01-01

The purpose of this study was to examine the extent to which the measures that make up each of the three separate accountability indices of school performance in South Carolina could be used to create an overall, reliable index of school performance. Data from public elementary, middle, and high schools in 2012/13 were used in confirmatory factor…

Direct numerical simulation of the Rayleigh-Taylor instability with the spectral element method

International Nuclear Information System (INIS)

Zhang Xu; Tan Duowang

2009-01-01

A novel method is proposed to simulate Rayleigh-Taylor instabilities using a specially-developed unsteady three-dimensional high-order spectral element method code. The numerical model used consists of Navier-Stokes equations and a transport-diffusive equation. The code is first validated with the results of linear stability perturbation theory. Then several characteristics of the Rayleigh-Taylor instabilities are studied using this three-dimensional unsteady code, including instantaneous turbulent structures and statistical turbulent mixing heights under different initial wave numbers. These results indicate that turbulent structures of Rayleigh-Taylor instabilities are strongly dependent on the initial conditions. The results also suggest that a high-order numerical method should provide the capability of simulating small scale fluctuations of Rayleigh-Taylor instabilities of turbulent flows. (authors)

Rayleigh Taylor instability of two superposed compressible fluids in un-magnetized plasma

International Nuclear Information System (INIS)

Sharma, P K; Tiwari, A; Argal, S; Chhajlani, R K

2014-01-01

The linear Rayleigh Taylor instability of two superposed compressible Newtonian fluids is discussed with the effect of surface tension which can play important roles in space plasma. As in both the superposed Newtonian fluids, the system is stable for potentially stable case and unstable for potentially unstable case in the present problem also. The equations of the problem are solved by normal mode method and a dispersion relation is obtained for such a system. The behaviour of growth rate is examined in the presence of surface tension and it is found that the surface tension has stabilizing influence on the Rayleigh Taylor instability of two superposed compressible fluids. Numerical analysis is performed to show the effect of sound velocity and surface tension on the growth rate of Rayleigh Taylor instability. It is found that both parameters have stabilizing influence on the growth rate of Rayleigh Taylor instability.

A Window into South Korean Culture: Stress and Coping in Female High School Students

Science.gov (United States)

VanderGast, Tim S.; Foxx, Sejal Parikh; Flowers, Claudia; Rouse, Andrew Thomas; Decker, Karen M.

2015-01-01

In an effort to increase multicultural competence, professional counselors in the United States analyzed archival data from high school students from Seoul, South Korea. A sample of all female (N = 577) high school students responded to survey questions related to stress and coping. Results demonstrated statistical significance in levels of stress…

Sleep Habits of Elementary and Middle School Children in South Texas

Directory of Open Access Journals (Sweden)

Salim Surani

2015-01-01

Full Text Available Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of elementary and middle school students, using the Children’s Sleep Habit Questionnaire-Sleep Self-Report Form, which assessed the domains of bedtime resistance, sleep onset delay, sleep anxiety, sleep duration, night awakening, and daytime sleepiness. Results. The survey was completed by 499 elementary and 1008 middle school children. Trouble sleeping was reported by 43% in elementary school, compared with 29% of middle school children. Fifty percent of middle school children did not like sleeping, compared with 26% in elementary school. Bedtime resistance, sleep onset delay, and nighttime awakening were more common among elementary school students. Daytime sleepiness was more common among the middle school children when compared to elementary school children. Conclusions. Sleep abnormalities are present in elementary school children with changes in sleep habits into middle school.

Elevated prevalence of malnutrition and malaria among school-aged children and adolescents in war-ravaged South Sudan.

Science.gov (United States)

Charchuk, Rhianna; Houston, Stan; Hawkes, Michael T

2015-01-01

Emerging as a sovereign state from decades of civil war, the Republic of South Sudan now faces poverty, a lack of health care infrastructure, a high burden of infectious diseases and a widespread food insecurity. School-aged children and youth, in particular, represent a high-risk demographic for malnutrition and infectious diseases. We screened 109 school-aged children and youth for nutritional status and malaria antigenaemia in Akuak Rak, South Sudan, and found a large proportion of underweight (77/109 = 73%) and prevalent malaria (44/109 = 40%). There was no significant association between malnutrition and malaria. This study represents one of the few published reports on child and youth nutritional status and malaria prevalence in South Sudan since its independence. The implementation of nutrition and malaria screening combined with evidence-based interventions in schools could help target this high burden vulnerable group.

Rayleigh-Taylor instability and mushroom-pattern formation in a two-component Bose-Einstein condensate

International Nuclear Information System (INIS)

Sasaki, Kazuki; Suzuki, Naoya; Saito, Hiroki; Akamatsu, Daisuke

2009-01-01

The Rayleigh-Taylor instability at the interface in an immiscible two-component Bose-Einstein condensate is investigated using the mean field and Bogoliubov theories. Rayleigh-Taylor fingers are found to grow from the interface and mushroom patterns are formed. Quantized vortex rings and vortex lines are then generated around the mushrooms. The Rayleigh-Taylor instability and mushroom-pattern formation can be observed in a trapped system.

Slavnov-Taylor constraints for nontrivial backgrounds

International Nuclear Information System (INIS)

Binosi, D.; Quadri, A.

2011-01-01

We devise an algebraic procedure for the evaluation of Green's functions in SU(N) Yang-Mills theory in the presence of a nontrivial background field. In the ghost-free sector the dependence of the vertex functional on the background is shown to be uniquely determined by the Slavnov-Taylor identities in terms of a certain 1-PI correlator of the covariant derivatives of the ghost and the antighost fields. At nonvanishing background this amplitude is shown to encode the quantum deformations to the tree-level background-quantum splitting. The approach only relies on the functional identities of the model (Slavnov-Taylor identities, b-equation, antighost equation) and thus it is valid beyond perturbation theory, and, in particular, in a lattice implementation of the background field method. As an example of the formalism we analyze the ghost two-point function and the Kugo-Ojima function in an instanton background in SU(2) Yang-Mills theory, quantized in the background Landau gauge.

Contexto y pensamiento de Charles Taylor sobre el consenso

Directory of Open Access Journals (Sweden)

Doris Elena Ospina Muñoz

2017-01-01

Full Text Available El artículo sostiene que el consenso no es un tema de primer orden en la filosofía política de Charles Taylor, pero una lectura orientada al problema puede ofrecer los elementos para establecer una teoría sobre dicha noción e identificar los argumentos para su justificación. Además, se enfatiza en el contexto de discusión que permite introducir la filosofía de Taylor como un modo de pensar sobre el consenso, alternativo al constructivismo.

Determinants of Adolescents' Career Development Competencies in Junior Secondary Schools of South Korea

Science.gov (United States)

Park, Joo-Ho; Rojewski, Jay W.; Lee, In Heok

2018-01-01

More attention is needed on the career development of adolescents, specifically disadvantaged students deemed at risk of school failure. We investigated the determinants on career development competencies of 9th graders in secondary school in South Korea. The data in this study included 394 principals, 6635 students, and the students' parents. Our…

Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

Energy Technology Data Exchange (ETDEWEB)

Ali, S., E-mail: shahid.ali@ncp.edu.p [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad (Pakistan); IPFN, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ahmed, Z. [COMSATS Institute of Information Technology, Department of Physics, Wah Campus (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ahmad, I. [COMSATS Institute of Information Technology, Department of Physics, Islamabad Campus (Pakistan)

2009-08-10

The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

International Nuclear Information System (INIS)

Ali, S.; Ahmed, Z.; Mirza, Arshad M.; Ahmad, I.

2009-01-01

The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

Factors Contributing to Sexual Violence at Selected Schools for Learners with Mild Intellectual Disability in South Africa.

Science.gov (United States)

Nyokangi, Doris; Phasha, Nareadi

2016-05-01

This paper reports part of the findings of a study which exposed sexual violence in schools for learners with mild intellectual disability in South Africa. Special attention was paid on factors contributing to such a problem. Data were collected using focus groups and individual interviews with 16 learners with mild intellectual disability at two special schools in South Africa. This was followed by individual interviews with the school nurse and social worker, and an analysis of schools' books of incidents. Factors contributing to sexual violence at schools for learners with mild intellectual disability included: (i) peer pressure, (ii) concealment of reported incidents of sexual violence, (iii) unsupervised areas linked to schools and (iv) arranged relationships. The following suggestions are put forth: (i) awareness programmes, (ii) sensitization of teachers about the consequences and prevention of sexual violence, (iii) boundaries within which the arranged relationship occurs, (iv) intensification of sexuality education and (v) supervision around the school premises. © 2015 John Wiley & Sons Ltd.

The nature, causes and effects of school violence in South African high schools

Directory of Open Access Journals (Sweden)

Vusumzi Nelson Ncontsa

2013-01-01

Full Text Available We sought to investigate the nature, causes and effects of school violence in four South African high schools. A purposive sample of five principals, 80 learners and 20 educators was selected from the four schools used in the study. A sequential mixed method approach was used in this study; both questionnaires and interviews were used. The design is divided into two phases, beginning with the collection and analysis of quantitative data, followed by the collection and analysis of qualitative data. The overall purpose of this design is that the qualitative data help explain or build upon initial quantitative results from the first phase of the study. The advantage of the design is that its two-phased nature makes it uncomplicated to implement and to report on. A combination of both quantitative and qualitative methods provides a better understanding of the research problem than either approach alone. A pilot study of the questionnaire was conducted in a school outside the province in which the study was done. Cronbach's alpha coefficient of the questionnaire was 0.72. This was a high positive coefficient and implied that the questionnaire used was reliable. The study found that bullying, vandalism, gangsterism, indiscipline, intolerance, and corporal punishment were prevalent in schools. Furthermore, the study found that school violence had the following effects on learners: loss of concentration; poor academic performance; bunking of classes; and depression. The implications of these findings are discussed in detail.

Direct Numerical Simulation of the Rayleigh−Taylor Instability with the Spectral Element Method

International Nuclear Information System (INIS)

Xu, Zhang; Duo-Wang, Tan

2009-01-01

A novel method is proposed to simulate Rayleigh−Taylor instabilities using a specially-developed unsteady three-dimensional high-order spectral element method code. The numerical model used consists of Navier–Stokes equations and a transport-diffusive equation. The code is first validated with the results of linear stability perturbation theory. Then several characteristics of the Rayleigh−Taylor instabilities are studied using this three-dimensional unsteady code, including instantaneous turbulent structures and statistical turbulent mixing heights under different initial wave numbers. These results indicate that turbulent structures of Rayleigh–Taylor instabilities are strongly dependent on the initial conditions. The results also suggest that a high-order numerical method should provide the capability of simulating small scale fluctuations of Rayleigh−Taylor instabilities of turbulent flows. (fundamental areas of phenomenology (including applications))

An Attempt to Extend Taylor-Spence Drive Theory to Vocational Choice Behavior

Science.gov (United States)

Sharf, Richard S.

1972-01-01

Predictions were made from Taylor-Spence drive theory about vocational choice behavior. Although the results did not specifically support the predictions made from Taylor-Spence theory, they indicated the potential usefulness of certain concepts in this theory and suggested several lines of inquiry for further research. (Author)

Reconnaissance study of the Taylor Mountains pluton, southwestern Alaska

Science.gov (United States)

Hudson, Travis L.; Miller, Marti L.; Klimasauskas, Edward P.; Layer, Paul W.

2010-01-01

The Taylor Mountains pluton is a Late Cretaceous to early Tertiary (median age 65 + or ? 2 Ma) epizonal, composite biotite granite stock located about 235 km (145 mi) northeast of Dillingham in southwestern Alaska. This 30 km2 (12 mi2) pluton has sharp and discordant contacts with hornfels that developed in Upper Cretaceous clastic sedimentary rocks of the Kuskokwim Group. The three intrusive phases in the Taylor Mountains pluton, in order of emplacement, are (1) porphyritic granite containing large K-feldspar phenocrysts in a coarse-grained groundmass, (2) porphyritic granite containing large K-feldspar and smaller, but still coarse, plagioclase, quartz, and biotite phenocrysts in a fine-grained groundmass, and (3) fine-grained, leucocratic, equigranular granite. The porphyritic granites have different emplacement histories, but similar compositions; averages are 69.43 percent SiO2, 1.62 percent CaO, 5.23 percent FeO+MgO, 3.11 percent Na2O, and 4.50 percent K2O. The fine-grained, equigranular granite is distinctly felsic compared to porphyritic granite; it averages 75.3 percent SiO2, 0.49 percent CaO, 1.52 percent FeO+MgO, 3.31 percent Na2O, and 4.87 percent K2O. Many trace elements including Ni, Cr, Sc, V, Ba, Sr, Zr, Y, Nb, La, Ce, Th, and Nd are strongly depleted in fine-grained equigranular granite. Trace elements are not highly enriched in any of the granites. Known hydrothermal alteration is limited to one tourmaline-quartz replacement zone in porphyritic granite. Mineral deposits in the Taylor Mountains area are primarily placer gold (plus wolframite, cassiterite, and cinnabar); sources for these likely include scattered veins in hornfels peripheral to the Taylor Mountain pluton. The granite magmas that formed the Taylor Mountains pluton are thought to represent melted continental crust that possibly formed in response to high heat flow in the waning stage of Late Cretaceous subduction beneath interior Alaska.

A cosmological Slavnov-Taylor identity

Science.gov (United States)

Collins, Hael; Holman, R.; Vardanyan, Tereza

2014-12-01

We develop a method for treating the consistency relations of inflation that includes the full time-evolution of the state. This approach relies only on the symmetries of the inflationary setting, in particular a residual conformal symmetry in the spatial part of the metric, along with general properties which hold for any quantum field theory. As a result, the consistency relations that emerge, which are essentially the Slavnov-Taylor identities associated with this residual conformal symmetry, apply very generally: they are true of the full Green's functions, hold largely independently of the particular inflationary model, and can be used for arbitrary states. We illustrate these techniques by showing the form assumed by the standard consistency relation between the two and three-point functions for the primordial scalar fluctuations when they are in a Bunch-Davies state. But because we have included the full evolution of the state, this approach works for a general initial state as well and does not need to have assumed that inflation began in the Bunch-Davies state. We explain how the Slavnov-Taylor identity is modified for these more general states.

Quantum effects on the Rayleigh-Taylor instability in a horizontal inhomogeneous rotating plasma

International Nuclear Information System (INIS)

Hoshoudy, G. A.

2009-01-01

The Rayleigh-Taylor instability is studied analytically in inhomogeneous plasma rotating uniformly in an external transverse magnetic field. The influence of the quantum mechanism is considered. For a stratified layer the linear growth rate is obtained. Some special cases that isolate the effect of various parameters on the growth rate of the Rayleigh-Taylor instability are discussed. It is shown that for some cases, the presence of the external transverse magnetic field beside the quantum effect will bring about more stability on the Rayleigh-Taylor instability.

Effects of thermal conduction and compressibility on Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Takabe, Hideaki; Mima, Kunioki.

1980-01-01

In order to study the stability of the ablation front in laser driven implosion, the thermal conduction and compressibility effects on the Rayleigh-Taylor instability are considered. It is found that the thermal conduction effect cannot stabilize the Rayleigh-Taylor mode, but reduce the growth rate in the short wavelength case. But, the growth rate is found not to differ from the classical value √gk in the long wavelength limit, where the compressibility is essential. (author)

School violence in an impoverished South African community.

Science.gov (United States)

Burnett, C

1998-08-01

The aim of this anthropological study was to create an understanding of school-related violence experienced by adolescents in the context of chronic poverty in a South African community. Qualitative methods of data collection such as participant observation, interviews, and group discussions were utilized for data collection. Sixteen children and three adults in turn kept diaries and wrote reports during the research period of three and one-half years (June 1992-December 1995). All the Standard seven pupils (N = 76) of the local school completed a self-concept questionnaire and wrote two essays about themselves and their lives, respectively. The ideology and structures of apartheid created a context of impoverishment and structural violence to which children were exposed. The school was one of the social institutions where children were subjected to structural, psychological, and physical violence on a daily basis. Violent behavior or discipline was justified as being just and an effective teaching practice by authoritarian parents and teachers. The manifestations of poverty included emotional erosion, a negative self-concept, and reactive violence. School-related violence was structurally interwoven with the very fabric of the social hierarchy of the school set-up and was sanctioned as an effective strategy to gain social control and discipline children. Poverty in itself provided the breeding-ground for violence at home and in the school. Children were caught up in a vicious circle of pro- and reactive violence and socialized to accept violence as an instrument of empowerment. Recommendations for possible intervention and further research are offered.

Taylor Dispersion Analysis as a promising tool for assessment of peptide-peptide interactions.

Science.gov (United States)

Høgstedt, Ulrich B; Schwach, Grégoire; van de Weert, Marco; Østergaard, Jesper

2016-10-10

Protein-protein and peptide-peptide (self-)interactions are of key importance in understanding the physiochemical behavior of proteins and peptides in solution. However, due to the small size of peptide molecules, characterization of these interactions is more challenging than for proteins. In this work, we show that protein-protein and peptide-peptide interactions can advantageously be investigated by measurement of the diffusion coefficient using Taylor Dispersion Analysis. Through comparison to Dynamic Light Scattering it was shown that Taylor Dispersion Analysis is well suited for the characterization of protein-protein interactions of solutions of α-lactalbumin and human serum albumin. The peptide-peptide interactions of three selected peptides were then investigated in a concentration range spanning from 0.5mg/ml up to 80mg/ml using Taylor Dispersion Analysis. The peptide-peptide interactions determination indicated that multibody interactions significantly affect the PPIs at concentration levels above 25mg/ml for the two charged peptides. Relative viscosity measurements, performed using the capillary based setup applied for Taylor Dispersion Analysis, showed that the viscosity of the peptide solutions increased with concentration. Our results indicate that a viscosity difference between run buffer and sample in Taylor Dispersion Analysis may result in overestimation of the measured diffusion coefficient. Thus, Taylor Dispersion Analysis provides a practical, but as yet primarily qualitative, approach to assessment of the colloidal stability of both peptide and protein formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

School illness absenteeism during 2009 influenza A (H1N1) pandemic--South Dakota, 2009-2010.

Science.gov (United States)

Kightlinger, Lon; Horan, Vickie

2013-05-01

Schools are important amplification settings of influenza virus transmission. We demonstrated correlation of school absenteeism (due to any illness) with other influenza A (H1N1) activity surveillance data during the 2009 pandemic. We collected nonspecific illness student absenteeism data from August 17, 2009 through April 3, 2010 from 187 voluntarily participating South Dakota schools using weekly online surveys. Relative risks (RR) were calculated as the ratio of the probability of absenteeism during elevated weeks versus the probability of absenteeism during the baseline weeks (RR = 1.89). We used Pearson correlation to associate absenteeism with laboratory-confirmed influenza cases, influenza cases diagnosed by rapid tests, influenza-associated hospitalizations and deaths reported in South Dakota during the 2009 H1N1 pandemic period. School-absenteeism data correlated strongly with data from these other influenza surveillance sources.

On generalizations of the series of Taylor, Lagrange, Laurent and Teixeira

Directory of Open Access Journals (Sweden)

L. M. B. C. Campos

1990-01-01

Full Text Available The classical theorems of Taylor, Lagrange, Laurent and Teixeira, are extended from the representation of a complex function F(z, to its derivative F(ν(z of complex order ν, understood as either a ‘Liouville’ (1832 or a ‘Rieman (1847’ differintegration (Campos 1984, 1985; these results are distinct from, and alternative to, other extensions of Taylor's series using differintegrations (Osler 1972, Lavoie & Osler & Tremblay 1976. We consider a complex function F(z, which is analytic (has an isolated singularity at ζ, and expand its derivative of complex order F(ν(z, in an ascending (ascending-descending series of powers of an auxiliary function f(z, yielding the generalized Teixeira (Lagrange series, which includes, for f(z=z−ζ, the generalized Taylor (Laurent series. The generalized series involve non-integral powers and/or coefficients evaluated by fractional derivatives or integrals, except in the case ν=0, when the classical theorems of Taylor (1715, Lagrange (1770, Laurent (1843 and Teixeira (1900 are regained. As an application, these generalized series can be used to generate special functions with complex parameters (Campos 1986, e.g., the Hermite and Bessel types.

Dominant Taylor Spectrum and Invariant Subspaces

Czech Academy of Sciences Publication Activity Database

Ambrozie, Calin-Grigore; Müller, Vladimír

2009-01-01

Roč. 61, č. 1 (2009), s. 101-111 ISSN 0379-4024 R&D Projects: GA ČR(CZ) GA201/06/0128 Institutional research plan: CEZ:AV0Z10190503 Keywords : Taylor spectrum * Scott-Brown technique * dominant spectrum Subject RIV: BA - General Mathematics Impact factor: 0.580, year: 2009

Screening for caries in targeted schools in the Blue Mountains and Hawkesbury districts, New South Wales, Australia: an evaluation of the School Assessment Program.

Science.gov (United States)

Chong, Gabriel Tse Feng; Evans, Robin Wendell; Dennison, Peter John

2011-11-01

  To determine if the school dental screening program in New South Wales, the School Assessment Program, achieved its aim of being the key entry point for high-risk children to receive care.   A secondary analysis was conducted on epidemiological data gathered in 16 primary schools in New South Wales (10 for the School Assessment Program and six for the non-School Assessment Program) in 2003. The validity of the School Assessment Program targeting criteria in identifying high-risk schools was determined. Post-screening treatment outcomes were evaluated from the assessment of treatment ratios.   There were negligible differences in the caries experience and proportions of high-risk children, irrespective of their School Assessment Program status. Sensitivity and specificity values were approximately 60% and 40%, respectively, using various case definitions of high risk applied to both children and schools. Deciduous dentition treatment ratios for School Assessment Program and non-School Assessment Program children with decayed, missing, and filled teeth (dmft) ≥1 ranged from 0.48 to 0.79 and from 0.47 to 0.73, respectively. Respective permanent dentition treatment ratios for School Assessment Program and non-School Assessment Program children with Decayed, Missing, and Filled Teeth (DMFT) ≥1 were 0.49-0.82 and 0.64-1.08.   The School Assessment Program failed to identify schools with high caries-risk children or confer post-screening caries treatment benefits. © 2011 Blackwell Publishing Asia Pty Ltd.

THE CHALLENGES OF SCHOOL-BASED YOUTH SUICIDE PREVENTION: EXPERIENCES AND PERCEPTIONS OF MENTAL HEALTH PROFESSIONALS IN SOUTH AFRICAN SCHOOLS

OpenAIRE

Woolf, Maryke; Bantjes, Jason; Kagee, Ashraf

2015-01-01

Youth suicidal behaviour poses a significant public health concern. Mental health care professionals working in schools have an important role to play in youth suicide prevention initiatives, although little is known of the experiences of this group of professionals in the developing world. The aim of this study was to explore the experiences of mental health professionals working in South African schools and document their insights, attitudes and beliefs regarding youth suicidal behaviour. I...

Spiritual character traits and leadership in the school workplace: An exploration of the relationship between spirituality and school leadership in some private and religiously affiliated schools in South Africa

Directory of Open Access Journals (Sweden)

Jaco S. Dreyer

2014-08-01

Full Text Available The South African educational system is in a crisis. This situation places huge demands on school principals and school management teams, and raises many theoretical and empirical questions. Transformational leadership is needed to deal with these challenges and complexities. Not all school leaders show the same level of transformational leadership. Some leaders conform more to other leadership styles. The aim of this article is to explore the relation between spiritual character traits and leadership styles from a theoretical and empirical perspective. The theoretical part focuses on the conceptualisation of leadership (styles and spirituality. The empirical research consists of a web-based survey conducted in some private and religiously affiliated schools in South Africa in 2011–2012. The Multifactor Leadership Questionnaire (MLQ and Cloninger’s shortened Temperament and Character Inventory (TCI-140 were used to measure leadership styles and spiritual traits respectively. Statistical procedures included confirmatory factor analysis, correlation (Pearson rho and regression analysis. Key findings are that leaders of private schools in South Africa mostly conform to a transformative leadership style, disagree with corrective leadership and strongly disagree with passive-avoidant leadership. Regarding the spiritual character traits they agree with self-transcendence and strongly agree with self-directedness. Spiritual character traits are strong predictors for transformational and passive-avoidant leadership. Higher levels of self-transcendence and self-directedness are strong predictors for transformational leadership. Our research suggests that traditional religious variables are less important as predictors of leadership style than spiritual character traits.

The feasibility of implementing food-based dietary guidelines in the South African primary-school curriculum.

Science.gov (United States)

Nguyen, Kim A; de Villiers, Anniza; Fourie, Jean M; Bourne, Lesley T; Hendricks, Michael K

2015-01-01

To explore the perceptions of educators from the Western Cape Province about the feasibility of implementing South African food-based dietary guidelines (FBDG) in the national curriculum of primary schools. Combined quantitative and qualitative methods. We report on the quantitative component. Twelve public primary schools of different socio-economic status in three education districts of the Western Cape: Metro Central, Metro East and Cape Winelands. Educators (n 256) participated in the self-completed questionnaire survey. Educators assessed that FBDG were appropriate to South African schoolchildren (94%), could be used as an education tool (97%) and fill gaps in the current curriculum about healthy dietary habits (91%). Besides Life Orientation, FBDG could be taught in other learning areas from grades 3 to 7 (9-13 years old). Important barriers to implementing FBDG in the curriculum were educators' workload (61%), insufficient time (46%), learners' disadvantaged background (43%) and educators' lack of knowledge (33%). Other approaches to teach children about FBDG included linking these to the National School Nutrition Programme (82%), school tuck shops (79%), parent meetings (75%), school nutrition policy (73%) and school assembly (57%). Educators in high-income schools perceived that learners' lifestyle was significantly worse (P school assembly were the best means to teach pupils about FBDG (P school curriculum is seen as important together with optimizing the school physical environment. Key factors required for successful implementation in the curriculum are sufficient educational materials, adequate time allocation and appropriate educator training.

"I'm Used to It Now": Experiences of Homophobia among Queer Youth in South African Township Schools

Science.gov (United States)

Msibi, Thabo

2012-01-01

This paper explores how sexually marginalised black high-school students from conservative schooling contexts in KwaZulu-Natal, South Africa, experience schooling. It draws on queer theories through life narratives in presenting findings from a small-scale interventionist project designed by the author. The project involved 14 participants…

Analytical and numerical analysis of finite amplitude Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Meiron, D.I.; Saffman, P.G.

1987-01-01

We summarize the results obtained in the last year. These include a simple model of bubble competition in Rayleigh-Taylor unstable flows which gives results which are in good agreement with experiment. In addition the model has been compared with two dimensional numerical simulations of inviscid Rayleigh-Taylor instability using the cloud-in-cell method. These simulations can now be run into the late time regime and can track the competition of as many as ten bubbles. The improvement in performance over previous applications of the cloud-in-cell approach is due to the application of finite difference techniques designed to handle shock-like structures in the vorticity of the interface which occur at late times. We propose to extend the research carried thus far to Rayleigh-Taylor problems in three dimensional and convergent geometries as well as to two-fluid instabilities in which interface roll-up is observed. Finally we present a budget for the fiscal year 1987-1988. 6 refs

Taylor O(h³) Discretization of ZNN Models for Dynamic Equality-Constrained Quadratic Programming With Application to Manipulators.

Science.gov (United States)

Liao, Bolin; Zhang, Yunong; Jin, Long

2016-02-01

In this paper, a new Taylor-type numerical differentiation formula is first presented to discretize the continuous-time Zhang neural network (ZNN), and obtain higher computational accuracy. Based on the Taylor-type formula, two Taylor-type discrete-time ZNN models (termed Taylor-type discrete-time ZNNK and Taylor-type discrete-time ZNNU models) are then proposed and discussed to perform online dynamic equality-constrained quadratic programming. For comparison, Euler-type discrete-time ZNN models (called Euler-type discrete-time ZNNK and Euler-type discrete-time ZNNU models) and Newton iteration, with interesting links being found, are also presented. It is proved herein that the steady-state residual errors of the proposed Taylor-type discrete-time ZNN models, Euler-type discrete-time ZNN models, and Newton iteration have the patterns of O(h(3)), O(h(2)), and O(h), respectively, with h denoting the sampling gap. Numerical experiments, including the application examples, are carried out, of which the results further substantiate the theoretical findings and the efficacy of Taylor-type discrete-time ZNN models. Finally, the comparisons with Taylor-type discrete-time derivative model and other Lagrange-type discrete-time ZNN models for dynamic equality-constrained quadratic programming substantiate the superiority of the proposed Taylor-type discrete-time ZNN models once again.

Samuel Taylor Coleridge’s

Directory of Open Access Journals (Sweden)

Aslı TEKİNAY

2000-01-01

Full Text Available There is a dark strain which can be traced in the poetry of all the major nineteenth century English romantic poets: a scepticism about the ultimate purpose of man's life, a sense of having lost a metaphysical certainty and faith in the presence of a benevolent power who maintains harmony and order in the universe. Samuel Taylor Coleridge is one of them. In "The Rime of the Ancient Mariner" and "Christabel", he reveals a nightmarish vision of the universe where moral order seems to be replaced by a cosmic "hap".

Characterization of the two-phase Taylor Couette flow

International Nuclear Information System (INIS)

Mehel A; Gabillet B; Djeridi H

2005-01-01

The focus of the present study concerns the effects of a dispersed phase on the structure of a quasi periodic Couette Taylor flow. The two phase flow patterns are investigated experimentally for the Taylor number Ta=780. Small bubbles (0.035 times as small as the gap) are generated by agitation of the upper free surface. Larger bubbles (0.15 times as small as the gap) are produced by injection at the bottom of the apparatus associated with a pressure drop. Void fraction, bubble size and velocity are measured, as well as the azimuthal and axial velocity components of the liquid. A premature transition to turbulence is pointed out and discussed according to the bubble size and their localization in the gap. (authors)

Applicability of Taylor's hypothesis in thermally driven turbulence

Science.gov (United States)

Kumar, Abhishek; Verma, Mahendra K.

2018-04-01

In this paper, we show that, in the presence of large-scale circulation (LSC), Taylor's hypothesis can be invoked to deduce the energy spectrum in thermal convection using real-space probes, a popular experimental tool. We perform numerical simulation of turbulent convection in a cube and observe that the velocity field follows Kolmogorov's spectrum (k-5/3). We also record the velocity time series using real-space probes near the lateral walls. The corresponding frequency spectrum exhibits Kolmogorov's spectrum (f-5/3), thus validating Taylor's hypothesis with the steady LSC playing the role of a mean velocity field. The aforementioned findings based on real-space probes provide valuable inputs for experimental measurements used for studying the spectrum of convective turbulence.

A qualitative analysis of facilities maintenance - a school governance function in South Africa

Directory of Open Access Journals (Sweden)

M I Xaba

2012-01-01

Full Text Available I analysed school facilities maintenance, a school governance function in South Africa. Qualitative interviews were conducted with 13 principals and three deputy principals as coordinators of this function at their schools. The interviews were purposively and conveniently selected to gather data regarding school facilities maintenance and gain insight into the challenges this function presents to schools and their governing bodies. Findings indicate that schools generally do not have organisational structures for planned facilities maintenance, nor do they have policies on facilities maintenance. Evidence of facilities maintenance at schools mainly relates to concerns with facilities repairs, (mostly "as the need arises" and general campus cleanliness; mostly with emergency and corrective forms of maintenance as opposed to crucial preventive maintenance. Therefore, there is a need for interim facilities maintenance committees and, in the long term, a whole-school approach to facilities maintenance that makes facilities maintenance a strategic lever for school functionality.

Effect of FLR correction on Rayleigh -Taylor instability of quantum and stratified plasma

International Nuclear Information System (INIS)

Sharma, P.K.; Tiwari, Anita; Argal, Shraddha; Chhajlani, R.K.

2013-01-01

The Rayleigh Taylor instability of stratified incompressible fluids is studied in presence of FLR Correction and quantum effects in bounded medium. The Quantum magneto hydrodynamic equations of the problem are solved by using normal mode analysis method. A dispersion relation is carried out for the case where plasma is bounded by two rigid planes z = 0 and z = h. The dispersion relation is obtained in dimensionless form to discuss the growth rate of Rayleigh Taylor instability in presence of FLR Correction and quantum effects. The stabilizing or destabilizing behavior of quantum effect and FLR correction on the Rayleigh Taylor instability is analyzed. (author)

Rayleigh-Taylor convective overturn in stellar collapse

International Nuclear Information System (INIS)

Bruenn, S.W.; Buchler, J.R.; Livio, M.

1979-01-01

Rayleigh--Taylor convective overturn in collapsing stellar cores is modeled with a one-dimensional parametrization. The results of a numerical hydrodynamic study are very encouraging and indicate that such an overturn could well be a dominant feature in the supernova explosion mechanism

Home and School Environmental Determinants of Science Achievement of South African Students

Science.gov (United States)

Juan, Andrea; Visser, Mariette

2017-01-01

Determinants of educational achievement extend beyond the school environment to include the home environment. Both environments provide tangible and intangible resources to students that can influence science achievement. South Africa provides a context where inequalities in socio-economic status are vast, thus the environments from whence…

Frictional Torque Reduction in Taylor-Couette Flows with Riblet-Textured Rotors

Science.gov (United States)

Raayai, Shabnam; McKinley, Gareth

2017-11-01

Inspired by the riblets on the denticles of fast swimming shark species, periodic surface microtextures of different shapes have been studied under laminar and turbulent flow conditions to understand their drag reduction mechanism and to offer guides for designing optimized low-friction bio-inspired surfaces. Various reports over the past four decades have suggested that riblet surfaces can reduce the frictional drag force in high Reynolds number laminar and turbulent flow regimes. Here, we investigate the effect of streamwise riblets on torque reduction in steady flow between concentric cylinders, known as Taylor-Couette Flow. Using 3D printed riblet-textured rotors and a custom-built Taylor-Couette cell which can be mounted on a rheometer we measure the torque on the inner rotor as a function of three different dimensionless parameters; the Reynolds number of the flow, the sharpness of the riblets, and the size of the riblets with respect to the scale of the Taylor-Couette cell. Our experimental results in the laminar viscous flow regime show a reduction in torque up to 10% over a wide range of Reynolds numbers, that is a non-monotonic function of the aspect ratio and independent of Re. However, after transition to the Taylor vortex regime, the modification in torque becomes a function of the Reynolds number, while remaining a non-monotonic function of the aspect ratio. Using finite volume modelling of the geometry we discuss the changes in the Taylor-Couette flow in presence of the riblets compared to the case of smooth rotors and the resulting torque reduction as a function of the parameter space defined above.

Filial Piety and Academic Motivation: High-Achieving Students in an International School in South Korea

Science.gov (United States)

Tam, Jonathan

2016-01-01

This study uses self-determination theory to explore the mechanisms of filial piety in the academic motivation of eight high-achieving secondary school seniors at an international school in South Korea, resulting in several findings. First, the students attributed their parents' values and expectations as a major source of the students'…

Fluid Dynamics And Mass Transfer In Two-Fluid Taylor-Couette Flow

International Nuclear Information System (INIS)

Baier, G.; Graham, M.D.

1998-01-01

The Taylor-Couette instability of a single liquid phase can be used to enhance mass transfer processes such as filtration and membrane separations. We consider here the possibility of using this instability to enhance interphase transport in a two-fluid systems, with a view toward improved liquid-liquid extractions for biotechnology applications. We investigate the centrifugal instability of a pair of radially stratified immiscible liquids in the annular gap between concentric, corotating cylinders: two-fluid Taylor-Couette flow. Experiments show that a two-layer flow with a well-defined interface and Taylor vortices in each phase can be obtained. The experimental results are in good agreement with predictions of inviscid arguments based on a two-phase extension of Rayleigh's criterion, as well as with detailed linear stability calculations. For a given geometry, the most stable configuration occurs for fluids of roughly (exactly in the inviscid limit) equal dynamic viscosities. A number of preliminary mass transfer experiments have also been performed, in the presence of axial counterflow. The onset of Taylor vortices coincides with a clear decrease in the extent of axial dispersion and an increase in the rate of interphase transport, thus suggesting that this flow geometry may provide an effective means for countercurrent chromatographic separations

Ethics, organ donation and tax: a reply to Quigley and Taylor.

Science.gov (United States)

Lippert-Rasmussen, Kasper; Petersen, Thomas Søbirk

2012-08-01

A national opt-out system of post-mortem donation of scarce organs is preferable to an opt-in system. Unfortunately, the former system is not always feasible, and so in a recent JME article we canvassed the possibility of offering people a tax break for opting-in as a way of increasing the number of organs available for donation under an opt-in regime. Muireann Quigley and James Stacey Taylor criticize our proposal. Roughly, Quigley argues that our proposal is costly and, hence, is unlikely to be implemented, while Taylor contests our response to a Titmuss-style objection to our scheme. In response to Quigley, we note that our proposal's main attraction lies in gains not reflected in the figures presented by Quigley and that the mere fact that it is costly does not imply that it is unfeasible. In response to Taylor, we offer some textual evidence in support of our interpretation of Taylor and responds to his favoured interpretation of the Titmuss-style objection that many people seem to want to donate to charities even if they can deduct their donations from their income tax. Finally, we show why our views do not commit us to endorsing a free organ-market.

Ekman-Hartmann layer in a magnetohydrodynamic Taylor-Couette flow.

Science.gov (United States)

Szklarski, Jacek; Rüdiger, Günther

2007-12-01

We study magnetic effects induced by rigidly rotating plates enclosing a cylindrical magnetohydrodynamic (MHD) Taylor-Couette flow at the finite aspect ratio HD=10 . The fluid confined between the cylinders is assumed to be liquid metal characterized by small magnetic Prandtl number, the cylinders are perfectly conducting, an axial magnetic field is imposed with Hartmann number Ha approximately 10 , and the rotation rates correspond to Reynolds numbers of order 10(2)-10(3). We show that the end plates introduce, besides the well-known Ekman circulation, similar magnetic effects which arise for infinite, rotating plates, horizontally unbounded by any walls. In particular, there exists the Hartmann current, which penetrates the fluid, turns in the radial direction, and together with the applied magnetic field gives rise to a force. Consequently, the flow can be compared with a Taylor-Dean flow driven by an azimuthal pressure gradient. We analyze the stability of such flows and show that the currents induced by the plates can give rise to instability for the considered parameters. When designing a MHD Taylor-Couette experiment, special care must be taken concerning the vertical magnetic boundaries so that they do not significantly alter the rotational profile.

Numerical study of Taylor bubbles with adaptive unstructured meshes

Science.gov (United States)

Xie, Zhihua; Pavlidis, Dimitrios; Percival, James; Pain, Chris; Matar, Omar; Hasan, Abbas; Azzopardi, Barry

2014-11-01

The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube. This type of bubble flow regime often occurs in gas-liquid slug flows in many industrial applications, including oil-and-gas production, chemical and nuclear reactors, and heat exchangers. The objective of this study is to investigate the fluid dynamics of Taylor bubbles rising in a vertical pipe filled with oils of extremely high viscosity (mimicking the ``heavy oils'' found in the oil-and-gas industry). A modelling and simulation framework is presented here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rise and reduce the computational effort without sacrificing accuracy. The numerical framework consists of a mixed control-volume and finite-element formulation, a ``volume of fluid''-type method for the interface capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Numerical examples of some benchmark tests and the dynamics of Taylor bubbles are presented to show the capability of this method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

Process development of starch hydrolysis using mixing characteristics of Taylor vortices.

Science.gov (United States)

Masuda, Hayato; Horie, Takafumi; Hubacz, Robert; Ohmura, Naoto; Shimoyamada, Makoto

2017-04-01

In food industries, enzymatic starch hydrolysis is an important process that consists of two steps: gelatinization and saccharification. One of the major difficulties in designing the starch hydrolysis process is the sharp change in its rheological properties. In this study, Taylor-Couette flow reactor was applied to continuous starch hydrolysis process. The concentration of reducing sugar produced via enzymatic hydrolysis was evaluated by varying operational variables: rotational speed of the inner cylinder, axial velocity (reaction time), amount of enzyme, and initial starch content in the slurry. When Taylor vortices were formed in the annular space, efficient hydrolysis occurred because Taylor vortices improved the mixing of gelatinized starch with enzyme. Furthermore, a modified inner cylinder was proposed, and its mixing performance was numerically investigated. The modified inner cylinder showed higher potential for enhanced mixing of gelatinized starch and the enzyme than the conventional cylinder.

3 CFR - Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor

Science.gov (United States)

2010-01-01

... to the Former Liberian Regime of Charles Taylor Presidential Documents Other Presidential Documents... of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a national... to the former Liberian regime of Charles Taylor, pursuant to the International Emergency Economic...

Bullying, "Cussing" and "Mucking About": Complexities in Tackling Homophobia in Three Secondary Schools in South London, UK

Science.gov (United States)

Warwick, Ian; Aggleton, Peter

2014-01-01

In countries such as the UK, schools have a responsibility to prevent all forms of bullying, including those related to sexual orientation. However, relatively little is known about how schools go about this work successfully. This study aimed to identify how three secondary schools in south London, England, were addressing homophobia. Three…

Student understanding of Taylor series expansions in statistical mechanics

Directory of Open Access Journals (Sweden)

Trevor I. Smith

2013-08-01

Full Text Available One goal of physics instruction is to have students learn to make physical meaning of specific mathematical expressions, concepts, and procedures in different physical settings. As part of research investigating student learning in statistical physics, we are developing curriculum materials that guide students through a derivation of the Boltzmann factor using a Taylor series expansion of entropy. Using results from written surveys, classroom observations, and both individual think-aloud and teaching interviews, we present evidence that many students can recognize and interpret series expansions, but they often lack fluency in creating and using a Taylor series appropriately, despite previous exposures in both calculus and physics courses.

Student understanding of Taylor series expansions in statistical mechanics

Science.gov (United States)

Smith, Trevor I.; Thompson, John R.; Mountcastle, Donald B.

2013-12-01

One goal of physics instruction is to have students learn to make physical meaning of specific mathematical expressions, concepts, and procedures in different physical settings. As part of research investigating student learning in statistical physics, we are developing curriculum materials that guide students through a derivation of the Boltzmann factor using a Taylor series expansion of entropy. Using results from written surveys, classroom observations, and both individual think-aloud and teaching interviews, we present evidence that many students can recognize and interpret series expansions, but they often lack fluency in creating and using a Taylor series appropriately, despite previous exposures in both calculus and physics courses.

Three-dimensional single-mode nonlinear ablative Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Yan, R.; Aluie, H.; Betti, R.; Sanz, J.; Liu, B.; Frank, A.

2016-01-01

The nonlinear evolution of the single-mode ablative Rayleigh-Taylor instability is studied in three dimensions. As the mode wavelength approaches the cutoff of the linear spectrum (short-wavelength modes), it is found that the three-dimensional (3D) terminal bubble velocity greatly exceeds both the two-dimensional (2D) value and the classical 3D bubble velocity. Unlike in 2D, the 3D short-wavelength bubble velocity does not saturate. The growing 3D bubble acceleration is driven by the unbounded accumulation of vorticity inside the bubble. The vorticity is transferred by mass ablation from the Rayleigh-Taylor spikes to the ablated plasma filling the bubble volume

Application of the Asymptotic Taylor Expansion Method to Bistable Potentials

Directory of Open Access Journals (Sweden)

Okan Ozer

2013-01-01

Full Text Available A recent method called asymptotic Taylor expansion (ATEM is applied to determine the analytical expression for eigenfunctions and numerical results for eigenvalues of the Schrödinger equation for the bistable potentials. Optimal truncation of the Taylor series gives a best possible analytical expression for eigenfunctions and numerical results for eigenvalues. It is shown that the results are obtained by a simple algorithm constructed for a computer system using symbolic or numerical calculation. It is observed that ATEM produces excellent results consistent with the existing literature.

The Reflexive Adaptations of School Principals in a "Local" South African Space

Science.gov (United States)

Fataar, Aslam

2009-01-01

This paper is an analysis of the work of three principals in an impoverished black township in post-apartheid South Africa. Based on qualitative approaches, it discusses the principals' entry into the township, and their navigation of their schools' surrounding social dynamics. It combines the lenses of "space" and…

Teacher and Learners' Belief in a Just World and Perspectives of Discipline of Grade 4-8 Learners in South African Schools

Science.gov (United States)

Human-Vogel, Salomé; Morkel, Jorina

2017-01-01

In the present study, we examine the personal belief in a just world (PBJW) for teachers and learners in predominantly Afrikaans-speaking South African schools, and the relationship between teachers' PBJW and their perception of problem behaviour in the classroom. The study is informed by national debates of school violence in South African…

Approximate expressions for the period of a simple pendulum using a Taylor series expansion

International Nuclear Information System (INIS)

Belendez, Augusto; Marquez, Andres; Ortuno, Manuel; Gallego, Sergi; Arribas, Enrique

2011-01-01

An approximate scheme for obtaining the period of a simple pendulum for large-amplitude oscillations is analysed and discussed. When students express the exact frequency or the period of a simple pendulum as a function of the oscillation amplitude, and they are told to expand this function in a Taylor series, they always do so using the oscillation amplitude as the variable, without considering that if they change the variable (in this paper to the new variable m), a different Taylor series expansion may be performed which is in addition more accurate than previously published ones. Students tend to believe that there is one and only one way of performing a Taylor series expansion of a specific function. The approximate analytical formula for the period is obtained by means of a Taylor expansion of the exact frequency taking into account the Kidd-Fogg formula for the period. This approach based on the Taylor expansion of the frequency about a suitable value converges quickly even for large amplitudes. We believe that this method may be very useful for teaching undergraduate courses on classical mechanics and helping students understand nonlinear oscillations of a simple pendulum.

Approximate expressions for the period of a simple pendulum using a Taylor series expansion

Energy Technology Data Exchange (ETDEWEB)

Belendez, Augusto; Marquez, Andres; Ortuno, Manuel; Gallego, Sergi [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain); Arribas, Enrique, E-mail: a.belendez@ua.es [Departamento de Fisica Aplicada, Escuela Superior de IngenierIa Informatica, Universidad de Castilla-La Mancha, Avda de Espana, s/n, E-02071 Albacete (Spain)

2011-09-15

An approximate scheme for obtaining the period of a simple pendulum for large-amplitude oscillations is analysed and discussed. When students express the exact frequency or the period of a simple pendulum as a function of the oscillation amplitude, and they are told to expand this function in a Taylor series, they always do so using the oscillation amplitude as the variable, without considering that if they change the variable (in this paper to the new variable m), a different Taylor series expansion may be performed which is in addition more accurate than previously published ones. Students tend to believe that there is one and only one way of performing a Taylor series expansion of a specific function. The approximate analytical formula for the period is obtained by means of a Taylor expansion of the exact frequency taking into account the Kidd-Fogg formula for the period. This approach based on the Taylor expansion of the frequency about a suitable value converges quickly even for large amplitudes. We believe that this method may be very useful for teaching undergraduate courses on classical mechanics and helping students understand nonlinear oscillations of a simple pendulum.

A numerical study of three-dimensional bubble merger in the Rayleigh endash Taylor instability

International Nuclear Information System (INIS)

Li, X.L.

1996-01-01

The Rayleigh endash Taylor instability arises when a heavy fluid adjacent to a light fluid is accelerated in a direction against the density gradient. Under this unstable configuration, a perturbation mode of small amplitude grows into bubbles of the light fluid and spikes of the heavy fluid. Taylor discovered the steady state motion with constant velocity for a single bubble or periodic bubbles in the Rayleigh endash Taylor instability. Read and Youngs studied the motion of a randomly perturbed fluid interface in the Rayleigh endash Taylor instability. They reported constant acceleration for the overall bubble envelope. Bubble merger is believed to cause the transition from constant velocity to constant acceleration. In this paper, we present a numerical study of this important physical phenomenon. It analyzes the physical process of bubble merger and the relationship between the horizontal bubble expansion and the vertical interface acceleration. A dynamic bubble velocity, beyond Taylor close-quote s steady state value, is observed during the merger process. It is believed that this velocity is due to the superposition of the bubble velocity with a secondary subharmonic unstable mode. The numerical results are compared with experiments. copyright 1996 American Institute of Physics

Acoustic regulations for housing and schools in Europe and South America

DEFF Research Database (Denmark)

Machimbarrena, Maria; Rasmussen, Birgit

2017-01-01

Acoustic regulations for housing and schools exist in most countries in Europe, the main reasons being protection of health of citizens in their homes and optimizing learning and work conditions in schools. Comparative studies in Europe have shown a high diversity of descriptors and limit values...... for acoustic requirements. Considering globalization and noise as a health issue, it is important to extend attention to other parts of the world and establish dialogue and cooperation. As a pilot study, acoustic regulations in three countries in South America, namely Argentina, Brazil and Chile, have been...... awareness among authorities and building industry and to exchange experience about construction solutions. The paper includes examples of specific acoustic requirements on airborne and impact sound insulation, noise from traffic and from service equipment for housing and schools and in addition...

Advection and Taylor-Aris dispersion in rivulet flow

Science.gov (United States)

Al Mukahal, F. H. H.; Duffy, B. R.; Wilson, S. K.

2017-11-01

Motivated by the need for a better understanding of the transport of solutes in microfluidic flows with free surfaces, the advection and dispersion of a passive solute in steady unidirectional flow of a thin uniform rivulet on an inclined planar substrate driven by gravity and/or a uniform longitudinal surface shear stress are analysed. Firstly, we describe the short-time advection of both an initially semi-infinite and an initially finite slug of solute of uniform concentration. Secondly, we describe the long-time Taylor-Aris dispersion of an initially finite slug of solute. In particular, we obtain the general expression for the effective diffusivity for Taylor-Aris dispersion in such a rivulet, and discuss in detail its different interpretations in the special case of a rivulet on a vertical substrate.

Constructions of legitimacy: the Charles Taylor trial

NARCIS (Netherlands)

Glasius, M.; Meijers, T.

2012-01-01

This article examines the discourses of the prosecution and the defence in the case of Charles Taylor before the Special Court for Sierra Leone. It contributes to current debates about the legitimacy and utility of international criminal justice, which have tended to neglect the examination of

Low sugar nutrition policies and dental caries: A study of primary schools in South Auckland.

Science.gov (United States)

Thornley, Simon; Marshall, Roger; Reynolds, Gary; Koopu, Pauline; Sundborn, Gerhard; Schofield, Grant

2017-05-01

The study assessed whether a healthy food policy implemented in one school, Yendarra Primary, situated in a socio-economically deprived area of South Auckland, had improved student oral health by comparing dental caries levels with students of similar schools in the same region with no such policy. Records of caries of the primary and adult teeth were obtained between 2007 and 2014 for children attending Yendarra, and were compared to those of eight other public schools in the area, with a similar demographic profile. Children were selected between the ages of 8 and 11 years. Linear regression models were used to estimate the strength of association between attending Yendarra school and dental caries. During the study period, 3813 records were obtained of children who attended dental examinations and the schools of interest. In a linear model, mean number of carious primary and adult teeth were 0.37 lower (95% confidence interval: 0.09-0.65) in Yendarra school children, compared to those in other schools, after adjustment for confounders. Pacific students had higher numbers of carious teeth (adjusted β coefficient: 0.25; 95% confidence interval: 0.03-0.46) than Māori. This nutrition policy, implemented in a school in the poorest region of South Auckland, which restricted sugary food and drink availability, was associated with a marked positive effect on the oral health of students, compared to students in surrounding schools. We recommend that such policies are a useful means of improving child oral health. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Mode transition in bubbly Taylor-Couette flow measured by PTV

International Nuclear Information System (INIS)

Yoshida, K; Tasaka, Y; Murai, Y; Takeda, T

2009-01-01

The drag acting to the inner cylinder in Taylor-Couette flow system can be reduced by bubble injection. In this research, relationship between drag reduction and change of vortical structure in a Taylor-Couette flow is investigated by Particle Tracking Velocimetry (PTV). The velocity vector field in the r-z cross section and the bubble concentration in the front view (z-θ plane) are measured. This paper describes the change of vortical structures with bubbles, and the mode transition that is sensitively affected by the bubbles is discussed. The bubbles accumulate in the three parts relative to vortex position by the interaction between bubbles and vortices. The status of bubble's distribution is different depending on position. This difference affects mode transition as its trigger significantly. The presence of bubbles affects the transition from toroidal mode to spiral mode but does not induce the transition from spiral mode to toroidal mode. Further we found that Taylor vortex bifurcates and a pair of vortices coalesces when the flow switches between spiral mode and toroidal mode.

Willingness to use corporal punishment among school administrators in South Carolina.

Science.gov (United States)

Medway, F J; Smircic, J M

1992-08-01

Administrators of 221 South Carolina public elementary and middle schools were surveyed regarding behaviors appropriate for corporal punishment. Analysis indicated that aggressive acts by students, both mild and severe, were rated appropriate for corporal punishment, and these were not typically seen as appropriate for a psychologist's intervention. Rather, psychologists were seen as useful for character problems such as lying, cheating, and tantrums.

Comparative description of migrant farmworkers versus other students attending South Texas schools: demographic, academic, and health characteristics.

Science.gov (United States)

Cooper, Sharon P; Weller, Nancy F; Fox, Erin E; Cooper, Sara R; Shipp, Eva M

2005-08-01

Little is known about academic performance, health, and social functioning of youth from migrant farmworker families. This study was designed to compare demographic, academic, health, and social data between migrant and nonmigrant youth residing in South Texas. Anonymous cross-sectional survey data were collected from 6954 middle and 3565 high school students. About 5% of South Texas middle and high school students reported belonging to a migrant family. Compared with nonmigrant students, migrant youth were more likely to miss and arrive late to school, sleep in class, and study fewer hours weekly. Migrant students reported fewer hours of nightly sleep, fewer hours spent with their friends, and more minor illnesses than nonmigrant youth. These results demonstrate the need for interventions specifically targeted to this vulnerable adolescent population.

Theoretical and numerical studies of Rayleigh-Taylor instabilities in magnetized plasmas; Etude theorique et numerique des instabilites Rayleigh-Taylor en plasmas magnetises

Energy Technology Data Exchange (ETDEWEB)

Ivanov, A.A

2001-06-01

The instabilities of Rayleigh-Taylor type are considered in the thesis. The topic of the thesis was inspired by recent advances in the physics of plasma compression, especially with the aid of systems like Z-pinch. Rayleigh-Taylor instability (RTI) plays an important role in the evolution of magnetized plasmas in these experiments, as well as in stellar plasmas and classic fluids. For the phenomena concerning the nuclear fusion the RTI is very often the factor limiting the possibility of compression. In the current work we try to examine in detail the characteristic features of the instabilities of this type in order to eliminate their detrimental influence. In this thesis we are studying both the general case of the 'classic' Rayleigh-Taylor instability (in incompressible fluids) and more specific cases of the instabilities of Rayleigh-Taylor type in magnetized plasmas, in the liners or wire array implosions etc. We have studied the influence of the Hall diffusion of magnetic field on the growth rate of the instability. We have obtained in this work a self-similar solution for the widening of the initial profile of the magnetic field and for the wave of the penetration of magnetic field. After that the subsequent evolution of the magnetic field in plasma opening switches (POS) has been examined. We have shown the possibility of the existence of a strong rarefaction wave for collisional and non-collisional cases. This wave can explain the phenomenon of the opening of POS. The effect of the suppression of Rayleigh-Taylor instability by forced oscillations of the boundary between two fluids permits us to propose some ideas for the experiments of inertial fusion. We have considered the general case of the instability, in other words, two incompressible viscous superposed fluids in a gravitational field. We have obtained an exact analytical expression for the growth rate and then we have analyzed the influence of the parameters of external &apos

Disentangling the origins of torque enhancement through wall roughness in Taylor-Couette turbulence

NARCIS (Netherlands)

Zhu, Xiaojue; Verzicco, Roberto; Lohse, Detlef

2017-01-01

Direct numerical simulations (DNS) are performed to analyse the global transport properties of turbulent Taylor-Couette flow with inner rough wall up to Taylor number Ta = 1010. The dimensionless torque Nuω shows an effective scaling of Nuω ∝ Ta0.42±0.01, which is steeper than the ultimate regime

The effects of job crafting on subjective well-being amongst South African high school teachers

Directory of Open Access Journals (Sweden)

Sergio Peral

2016-09-01

Full Text Available Orientation: Job crafting can result in a number of positive outcomes for teachers, such as increased meaningfulness and engagement at work. Increased work engagement and psychological meaningfulness may yield positive benefits for the practice of teaching, thus highlighting the pivotal role of job crafting. Research purpose: The study’s aim was to investigate the relationship between job crafting and subjective well-being amongst South African high school teachers. Subjective well-being comprises psychological meaningfulness and work engagement. The potential mediating effect that psychological meaningfulness had on this relationship was further explored. Motivation for the study: Being in a highly stressful occupation, teachers need to continuously find ways to craft their working practices in order to deal effectively with their job demands and to capitalise on their available job resources. Furthermore, South Africa’s current education system calls for serious proactive measures to be taken to improve and rectify the current status, such as job crafting. Research approach, design and method: A quantitative, cross-sectional survey design was used and administered to a sample of South African high school teachers situated in Gauteng, South Africa (N = 251. Main findings: A positive relationship was found between job crafting (increasing structural resources and challenging job demands and work engagement. Furthermore, psychological meaningfulness mediated the relationship between job crafting and work engagement amongst the sampled high school teachers. Practical/managerial implications: Teachers who craft their work to better suit their preferences and needs will obtain greater meaning in their work and experience increased levels of work engagement. Training programmes and/or group-based interventions targeted around job crafting techniques may be particularly useful in the South African teaching context. Contribution/value-add: This

Eating disorders among adolescents in South African public schools – a biblical perspective

Directory of Open Access Journals (Sweden)

S. Schoeman

2005-07-01

Full Text Available Society’s obsession with thinness and body image is part of every school’s hidden curriculum. The ideal to be skinny and thin resulted in an escalation in eating disorders among adolescents in South Africa. Some of the learners are only in the senior phase (Grades 7 to 9 of the general education and training band. It is therefore timely to review the problem of eating disorders, especially among adolescents in South African public schools. The purpose of this article is firstly to provide policy-makers, curriculum developers, educational ad-ministrators and educators with knowledge of the biblical view of health and to illustrate the pedagogical potential of such a view. Secondly the purpose is to assist Christian educators in teaching learners in public schools the necessary knowledge, skills, values and attitudes to counteract eating disorders by using, among other things, biblical truths.

Health behaviour and the school environment in New South Wales, Australia.

Science.gov (United States)

McLellan, L; Rissel, C; Donnelly, N; Bauman, A

1999-09-01

The relationship between the school environment and health has infrequently been examined. This study sought to examine the association between school students' perceptions of their school environment, teachers' and peers' support and their health behaviours. A cross sectional descriptive survey by supervised self-administration was conducted in 1996 based on the international WHO collaborative survey of school children's health and lifestyle (the HBSC Study) and extended in an Australian setting. Randomly sampled primary and secondary schools from Catholic, Independent and Government education sectors throughout New South Wales (NSW), Australia, were invited to participate. The final sample included 3918 school students attending Year 6 (primary school), Year 8 and Year 10 (high school) from 115 schools. The main outcome measures were self-reported health status and 7 health behaviours (tobacco use, alcohol use, physical activity, dental hygiene, nutritional intake, seat belt and bicycle helmet use). Independent variables included student perceptions of the school environment, perceptions of teachers' and peers' support. Girls, Year 6 students and students who have less than $19 a week to spend were significantly more likely to have positive perceptions towards their school environment, teacher(s) and peers. Students who had positive perceptions regarding their school environment and perceived their teachers as supportive were significantly more likely to engage in health promoting behaviours adjusting for age, sex and average weekly pocket money. A supportive peer environment was not associated with positive health behaviour. Health promotion practitioners need to consider the impact of the school environment on health behaviours of school students. In particular, practitioners should consider intervention models that improve the school environment as a key strategy within a health promoting school.

A Taylor weak-statement algorithm for hyperbolic conservation laws

Science.gov (United States)

Baker, A. J.; Kim, J. W.

1987-01-01

Finite element analysis, applied to computational fluid dynamics (CFD) problem classes, presents a formal procedure for establishing the ingredients of a discrete approximation numerical solution algorithm. A classical Galerkin weak-statement formulation, formed on a Taylor series extension of the conservation law system, is developed herein that embeds a set of parameters eligible for constraint according to specification of suitable norms. The derived family of Taylor weak statements is shown to contain, as special cases, over one dozen independently derived CFD algorithms published over the past several decades for the high speed flow problem class. A theoretical analysis is completed that facilitates direct qualitative comparisons. Numerical results for definitive linear and nonlinear test problems permit direct quantitative performance comparisons.

Influence of velocity shear on the Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Guzdar, P.N.; Satyanarayana, P.; Huba, J.D.; Ossakow, S.L.

1982-01-01

The influence of a transverse velocity shear on the Rayleigh-Taylor instability is investigated. It is found that a sheared velocity flow can substantially reduce the growth rate of the Rayleigh-Taylor instability in short wavelength regime (i.e., kL>1 where L is the scale length of the density inhomogeneity), and causes the growth rate to maximize at kL<1.0. Applications of this result to ionospheric phenomena [equatorial spread F (ESF) and ionospheric plasma clouds] are discussed. In particular, the effect of shear could account for, at times, the 100's of km modulation observed on the bottomside of the ESF ionosphere and the km scale size wavelengths observed in barium cloud prompt striation phenomena

Corporal Punishment Contestations, Paradoxes and Implications for School Leadership: A Case Study of Two South African High Schools

Science.gov (United States)

Makhasane, Sekitla Daniel; Chikoko, Vitallis

2016-01-01

The continued use of corporal punishment in some South African schools and the reasons advanced for it make this subject topical even now, twenty years after the abolition of this practice. Corporal punishment is a worrying issue among human rights activists and scholars. This paper reports on contestations and paradoxes regarding the use of…

An epidemiological study of sleep quality in adolescents in South China: a school-based study.

Science.gov (United States)

Zhou, H-Q; Shi, W-B; Wang, X-F; Yao, M; Cheng, G-Y; Chen, P-Y; Li, D-G

2012-07-01

This study explored the prevalence of disturbed sleep and investigated its distribution characteristics and associated factors in adolescents in South China. Junior middle school and senior high school students (n = 1221) were recruited from schools in Shanghai, China. Students completed a questionnaire using the Pittsburgh Sleep Quality Index and factors associated with disturbed sleep. The prevalence of a tendency towards poor sleep was 34.32% [95% confidence interval (CI): 31.66-36.98] with no significant difference between genders. This tendency increased with age, yielding a significant group effect (P school and high school, the propensity towards poor sleep was 31.34% (95% CI: 28.29-34.39) and 42.22% (95% CI: 36.92-47.52) respectively. The factors associated with poor sleep were more television viewing during weekdays [odds ratio (OR): 1.56, CI: 1.36-1.71], more frequent computer/Internet use (OR: 1.25, CI: 1.08-1.39), earlier school starting time (OR: 1.12, CI: 1.07-1.28), and more time on homework during weekdays (OR: 1.78, CI: 1.51-1.98) and weekends (OR: 1.35, CI: 1.21-1.52) A tendency towards poor sleep is common in adolescents in South China and its incidence increases with age. The factors associated with this phenomenon indicate that poor sleep in adolescents could be improved, at least partly, by reducing the use of visual technologies and by changing school timetables. © 2011 Blackwell Publishing Ltd.

Taylor Series-Based Long-Term Creep-Life Prediction of Alloy 617

International Nuclear Information System (INIS)

Yin, Song Nan; Kim, Woo Gon; Kim, Yong Wan; Park, Jae Young; Kim, Soen Jin

2010-01-01

In this study, a Taylor series (T-S) model based on the Arrhenius, McVetty, and Monkman-Grant equations was developed using a mathematical analysis. In order to reduce fitting errors, the McVetty equation was transformed by considering the first three terms of the Taylor series equation. The model parameters were accurately determined by a statistical technique of maximum likelihood estimation, and this model was applied to the creep data of alloy 617. The T-S model results showed better agreement with the experimental data than other models such as the Eno, exponential, and L-M models. In particular, the T-S model was converted into an isothermal Taylor series (IT-S) model that can predict the creep strength at a given temperature. It was identified that the estimations obtained using the converted ITS model was better than that obtained using the T-S model for predicting the long-term creep life of alloy 617

Practical radiology education in South African Dental Schools, 1981

International Nuclear Information System (INIS)

Farman, A.G.; Nortje, C.J.

1981-01-01

The current position of practical preclinical and clinical training in dento-maxillo-facial radiography for dental students and oral hygiene students in South Africa is reviewed. Special attention is given to factors in methodology which have an influence on radiation protection. Results indicate that there is a fairly high degree of standardization in dento-maxillo-facial radiography instruction in South Africa. The preference for the lead-lined or shielded open-ended cones is in keeping with the tenets of radiation protection. The use of pointed cones for intraoral radiography is not a good choice, as this causes scatter radiation. The wide use of the Rinn XCP(R) filmholding device in South African dental schools for the parallelling technique lessens the chance of cone cutting, and hence reduces the likelihood of needing to reexpose the patient due to that technical error. Additionally, the parallelling technique allows a more accurate assessment of alveolar bone loss from periodontal disease, and allows a better judgement of the relationship between the roots of maxillary teeth and the floor of the maxillary sinus, than does the bisecting angle technique. During the past decade, fiarly consistent parameters have been developed in dento-maxillo-facial radiography concerning preclinical and clinical training of dental and oral hygiene students [af

Normalization of the parameterized Courant-Snyder matrix for symplectic factorization of a parameterized Taylor map

International Nuclear Information System (INIS)

Yan, Y.T.

1991-01-01

The transverse motion of charged particles in a circular accelerator can be well represented by a one-turn high-order Taylor map. For particles without energy deviation, the one-turn Taylor map is a 4-dimensional polynomials of four variables. The four variables are the transverse canonical coordinates and their conjugate momenta. To include the energy deviation (off-momentum) effects, the map has to be parameterized with a smallness factor representing the off-momentum and so the Taylor map becomes a 4-dimensional polynomials of five variables. It is for this type of parameterized Taylor map that a mehtod is presented for converting it into a parameterized Dragt-Finn factorization map. Parameterized nonlinear normal form and parameterized kick factorization can thus be obtained with suitable modification of the existing technique

Irregular wall roughness in turbulent Taylor-Couette flow

Science.gov (United States)

Berghout, Pieter; Zhu, Xiaojue; Verzicco, Roberto; Lohse, Detlef; Stevens, Richard

2017-11-01

Many wall bounded flows in nature, engineering and transport are affected by surface roughness. Often, this has adverse effects, e.g. drag increase leading to higher energy costs. A major difficulty is the infinite number of roughness geometries, which makes it impossible to systematically investigate all possibilities. Here we present Direct Numerical Simulations (DNS) of turbulent Taylor-Couette flow. We focus on the transitionally rough regime, in which both viscous and pressure forces contribute to the total wall stress. We investigate the effect of the mean roughness height and the effective slope on the roughness function, ΔU+ . Also, we present simulations of varying Ta (Re) numbers for a constant mean roughness height (kmean+). Alongside, we show the behavior of the large scale structures (e.g. plume ejection, Taylor rolls) and flow structures in the vicinity of the wall.

Sociotechnical Narratives in Rural, High-Poverty Elementary Schools: Comparative Findings from East Texas and South India

Science.gov (United States)

Byker, Erik J.

2014-01-01

The article's purpose is to compare case studies of computer technology use at two rural elementary schools across two international settings. This study uses the Social Construction of Technology (SCOT) theory to guide this comparative investigation of how elementary school teachers and students in East Texas and South India construct meaning for…

Impediments to the successful reconstruction of African immigrant teachers' professional identities in South African schools

Directory of Open Access Journals (Sweden)

Saloshna Vandeyar

2014-06-01

Full Text Available The purpose of this study was to explore difficulties and challenges that confront African immigrant teachers as they attempt to reconstruct their professional identities in South African schools. The study was qualitative in nature and utilized narrative inquiry and the case study approach. Data-gathering techniques included a mix of semi-structured interviews, observations, focus group interviews, field notes and researcher journals. Data were analysed using grounded theory and content analysis methods. Findings of the study revealed that immigration status, employment status, attitudes of indigenous learners and holding on to former culture or way of knowing due to lack of induction or mentoring, were impediments to the successful reconstruction of African immigrant teachers' professional identities in South African schools.

School Language Profiles: Valorizing Linguistic Resources in Heteroglossic Situations in South Africa

Science.gov (United States)

Busch, Brigitta

2010-01-01

Although South Africa is committed to a policy of linguistic diversity, the language-in-education policy is still plagued by the racialization of language issues under apartheid and, more recently, by new challenges posed by internal African migration. Drawing on the experience of a school in the Western Cape Province, this paper explores the role…

Evaluation of a school-based intervention programme for South African children of divorce.

Science.gov (United States)

Botha, Cornelius J; Wild, Lauren G

2013-01-01

Parental divorce affects approximately 30 000 South African children annually. This pilot study aimed to evaluate the effectiveness of the Children of Divorce Intervention Programme (CODIP) at two South African schools. CODIP is a preventively oriented group programme which was developed to foster resilience by helping children cope more effectively with possible academic, behavioural, and emotional problems brought about by their parents' divorce. Twenty-five 10- to 14-year-old boys from two primary schools were randomly assigned to 2 experimental groups and 1 delayed intervention control group. The experimental groups attended 12 one-hour weekly sessions; the control group received no intervention until after the study was completed. Children's understanding of divorce related events and social, emotional and behavioural adjustment was assessed one week before the intervention and three months thereafter using a battery of self-rated, teacher-rated and parent-rated questionnaires. One-way ANOVAs indicated no statistically significant decline in children's self-reported problematic beliefs about divorce or total difficulties. However, teachers' and parents' ratings indicated that compared to the control group, the combined experimental groups showed significant improvement in their general behavioural, emotional and social adjustment after programme participation. The results suggest that South African children who experience parental divorce may benefit from participation in CODIP.

A depositional model for the Taylor coal bed, Martin and Johnson counties, eastern Kentucky

Science.gov (United States)

Andrews, W.M.; Hower, J.C.; Ferm, J.C.; Evans, S.D.; Sirek, N.S.; Warrell, M.; Eble, C.F.

1996-01-01

This study investigated the Taylor coal bed in Johnson and Martin counties, eastern Kentucky, using field and petrographic techniques to develop a depositional model of the coal bed. Petrography and chemistry of the coal bed were examined. Multiple benches of the Taylor coal bed were correlated over a 10 km distance. Three sites were studied in detail. The coal at the western and eastern sites were relatively thin and split by thick clastic partings. The coal at the central site was the thickest and unsplit. Two major clastic partings are included in the coal bed. Each represents a separate and distinct fluvial splay. The Taylor is interpreted to have developed on a coastal plain with periodic flooding from nearby, structurally-controlled fluvial systems. Doming is unlikely due to the petrographic and chemical trends, which are inconsistent with modern Indonesian models. The depositional history and structural and stratigraphic setting suggest contemporaneous structural influence on thickness and quality of the Taylor coal bed in this area.

The simultaneous onset and interaction of Taylor and Dean instabilities in a Couette geometry

International Nuclear Information System (INIS)

Hills, C P; Bassom, A P

2005-01-01

The fluid flow between a pair of coaxial circular cylinders generated by the uniform rotation of the inner cylinder and an azimuthal pressure gradient is susceptible to both Taylor and Dean type instabilities. The flow can be characterised by two parameters: a measure of the relative magnitude of the rotation and pressure effects and a non-dimensional Taylor number. Neutral curves associated with each instability can be constructed but it has been suggested that these curves do not cross but rather posses 'kinks'. Our work is based in the small gap, large wavenumber limit and considers the simultaneous onset of Taylor and Dean instabilities. The two linear instabilities interact at exponentially small orders and a consistent, matched asymptotic solution is found across the whole annular domain, identifying five regions of interest: two boundary adjustment regions and three internal critical points. We construct necessary conditions for the concurrent onset of the linear Taylor and Dean instabilities and show that neutral curve crossing is possible

Educational outcomes: Pathways and performance in South African high schools

OpenAIRE

Reddy, Vijay; van der Berg, Servaas; Janse van Rensburg, Dean; Taylor, Stephen

2012-01-01

We analysed the pathways and performances in mathematics of high (secondary) school students in South Africa using a panel-like data set of Grade 8 students who participated in the 2002 Trends in International Mathematics and Science Study (TIMSS) and who were tracked to Grade 12 examination data sets. We examined the relationship between TIMSS mathematics performance and reaching Grade 12, the selection of and performance in Grade 12 mathematics, and success rates in the matriculation examin...

76 FR 24479 - In the Matter of the Taylor Lumber and Treating Superfund Site, Sheridan, Oregon, Amendment to...

Science.gov (United States)

2011-05-02

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9300-9] In the Matter of the Taylor Lumber and Treating... Taylor Lumber and Treating Site, which PWPO was acquiring, in exchange for several obligations related to...-553- 0705. Comments should reference the Taylor Lumber and Treating Superfund Site in Sheridan, Oregon...

Building a Nation: Religion and Values in the Public Schools of the USA, Australia, and South Africa

Science.gov (United States)

Mawdsley, Ralph D.; Cumming, Jacqueline Joy; de Waal, Elda

2008-01-01

Although the systems of public schools differ among Australia, South Africa and the USA, all three countries recognize that religion plays a significant role in determining values. All three countries have written constitutions but only South Africa and the USA have a Bill of Rights that protects persons' exercise of religious beliefs. In…

The promotion of oral health in health-promoting schools in KwaZulu-Natal Province, South Africa

OpenAIRE

Reddy, M; Singh, S

2017-01-01

BACKGROUND. Oral health promotion is a cost-effective strategy that can be implemented at schools for the prevention of oral diseases. The importance and value of school-based interventions in children has been identified in South Africa (SA). Although oral health strategies include integrated school-based interventions, there is a lack of published evidence on whether these strategies have been translated into practice and whether these programmes have been evaluated. OBJECTIVE. To assess th...

From Digital Divide to Digital Equity: Learners' ICT Competence in Four Primary Schools in Cape Town, South Africa

Science.gov (United States)

Gudmundsdottir, G. B.

2010-01-01

This study explores factors influencing the digital divide in four schools in Cape Town, South Africa. Three of the schools are for disadvantaged learners whereas the fourth was previously for whites only. All the schools use ICT in their curriculum delivery and thereby support the emphasis of provincial educational authorities on ICT access for…

Evidence of Rayleigh-Taylor instabilities in tri-layer targets

International Nuclear Information System (INIS)

Galmiche, D.; Holstein, P.A.; Meyer, B.; Rostaing, M.; Wilke, N.

1988-01-01

The results of the experiments carried out on a laser system are reported. The work is performed in order to investigate the problem of target instability under ablative acceleration and to get direct evidence of Rayleigh-Taylor instabilities. Tri-layer experiments assert the validity of X-ray spectroscopy measurements as experimental method to investigate the problem. A mixing zone is evidenced and general trends of mixing development versus target acceleration are coherent with numerical simulations. Results obtained with optical smoothing demonstrate that the apparent mixing is not due to large scale illumination non uniformities. Numerical simulations confirm that Rayleigh-Taylor instability seems to be the dominant process responsible for the mixing. Benefit of time resolved spectroscopy appears attractive and gives a real knowledge of the mixing layer

Home and school resources as predictors of mathematics performance in South Africa

Directory of Open Access Journals (Sweden)

Mariette Visser

2015-02-01

Full Text Available The creation of an environment conducive to learning is vitally important in the academic achievement of learners. Such an environment extends beyond the classroom and school to include the home. It is from these environments that learners draw resources, both tangible and intangible, that impact on their educational experience. While current bodies of literature focus on either school or home resources, this paper looks at both. Multiple regression analyses were conducted on the 2011 Trends in International Mathematics and Science Study (TIMSS data to determine the resources factors that influence South African learners' performance in mathematics. The findings reveal that both school and home environments play significant roles in learners' mathematics performance. This paper therefore suggests that it is not only the socio-economic factors of schools that impact learners' mathematics performance, but also that higher levels of parental education have a significant positive influence.

The Educationally Challenged American School District.

Science.gov (United States)

Clinchy, Evans

1998-01-01

Two national reform movements--one focused on creating small, autonomous schools, the other fixated on a standardization agenda--are basically in conflict. The standards movement is touting the traditional, top-down, centralized, bureaucratic system modeled after Frederick Taylor and his efficiency experts. Progressive, decentralized initiatives…

75 FR 42281 - Continuation of the National Emergency With Respect To the Former Liberian Regime of Charles Taylor

Science.gov (United States)

2010-07-21

... National Emergency With Respect To the Former Liberian Regime of Charles Taylor On July 22, 2004, by... Taylor, pursuant to the International Emergency Economic Powers Act (50 U.S.C. 1701-1706). The President... States constituted by the actions and policies of former Liberian President Charles Taylor and other...

Women's Work or Creative Work? Embroidery in New South Wales High Schools

Science.gov (United States)

Wood, Susan

2009-01-01

Embroidery is traditionally regarded as women's work and the teaching of embroidery as a means of preparing young women for domesticity, a view which has been reinforced by historians studying changes in the high school art curriculum that occurred with the introduction of the Wyndham Scheme in New South Wales in the early 1960s. This paper argues…

Fostering Movements or Silencing Voices: School Principals in Egypt and South Africa

Science.gov (United States)

Marsh, Tyson E. J.; Knaus, Christopher B.

2016-01-01

In this paper, we examine the role of educational leadership in promoting and/or challenging racism as an intentional outcome of schooling. We focus on Egypt and South Africa, two countries uniquely framed as both deeply divided by race, religion, and/or class and as models of resistance and conscious activism. We draw upon experiences working as,…

"Girls Are Not Free"--In and out of the South African School

Science.gov (United States)

Bhana, Deevia

2012-01-01

Interviews conducted with township girls in South Africa show enduring experiences of sexual violence both in and out of the school. Fear of boys and men were articulated in relation to boyfriends, male teachers, men in the township neighbourhood and men in the home. While the girls attempted to exercise agency in arresting their fears, these…

Ruptured peroneal aneurysm after infrapopliteal prosthetic bypass with Taylor patch

Directory of Open Access Journals (Sweden)

Florian Enzmann

Full Text Available Introduction: A 45-year-old mailman underwent an implantation of a femoro-peroneal polytetrafluoroethylene (PTFE bypass with a distal Taylor patch six years prior to admission after two failed autologous reconstructions and extensive fasciotomy. The initial pathology was an acute ischemia due to popliteal entrapment with subsequent popliteal thrombectomy. Report: The patient was examined because of pain, reduction of walking distance and development of a palpable mass at the medial fasciotomy site. A 6-cm pseudoaneurysm with complete disruption of the suture line of the vein patch was discovered and resected. Arterial continuity with a vein interposition graft was established using non-reversed cephalic vein. Conclusion: The etiology of the aneurysm is not entirely clear. One may argue that the fourth revascularization could have been performed with an arm vein instead of a prosthetic graft with the probability of a better long term patency in a young patient. 15 months after the procedure the bypass is patent and the patient is without any symptoms. This complication of a Taylor patch has not been reported before. Keywords: Taylor patch, Pseudoaneurysm, Infrapopliteal bypass

Taylor bubbles at high viscosity ratios: experiments and numerical simulations

Science.gov (United States)

Hewakandamby, Buddhika; Hasan, Abbas; Azzopardi, Barry; Xie, Zhihua; Pain, Chris; Matar, Omar

2015-11-01

The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube, often occurring in gas-liquid slug flows in many industrial applications, particularly oil and gas production. The objective of this study is to investigate the fluid dynamics of three-dimensional Taylor bubble rising in highly viscous silicone oil in a vertical pipe. An adaptive unstructured mesh modelling framework is adopted here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rising and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control volume and finite element formulation, a `volume of fluid'-type method for the interface-capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Experimental results for the Taylor bubble shape and rise velocity are presented, together with numerical results for the dynamics of the bubbles. A comparison of the simulation predictions with experimental data available in the literature is also presented to demonstrate the capabilities of our numerical method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

Editorial: Howard Taylor Ricketts

Directory of Open Access Journals (Sweden)

Facultad de Medicina Revista

1941-05-01

Full Text Available Howard Taylor Ricketts nació en Findlay (Ohio el 9 de febrero de 1871. Pasó su niñez en Nebraska, recibió su título de bachiller en la Universidad de ese Estado, en 1894 y se graduó de médico en Northwestern University, en 1897. Hizo su internado en el Cook-County de Chicago. Practicó estdios especiales de dermatología en el Rush Medical College durante dos años. En 1900 contrajo matrimonio con Myra Tubbs, inteligente mujer que colaboró en sus trabajos con rara devoción, ardiente interés y constante estímulo.

Current management for word finding difficulties by speech-language therapists in South African remedial schools.

Science.gov (United States)

de Rauville, Ingrid; Chetty, Sandhya; Pahl, Jenny

2006-01-01

Word finding difficulties frequently found in learners with language learning difficulties (Casby, 1992) are an integral part of Speech-Language Therapists' management role when working with learning disabled children. This study investigated current management for word finding difficulties by 70 Speech-Language Therapists in South African remedial schools. A descriptive survey design using a quantitative and qualitative approach was used. A questionnaire and follow-up focus group discussion were used to collect data. Results highlighted the use of the Renfrew Word Finding Scale (Renfrew, 1972, 1995) as the most frequently used formal assessment tool. Language sample analysis and discourse analysis were the most frequently used informal assessment procedures. Formal intervention programmes were generally not used. Phonetic, phonemic or phonological cueing were the most frequently used therapeutic strategies. The authors note strengths and raise concerns about current management for word finding difficulties in South African remedial schools, particularly in terms of bilingualism. Opportunities are highlighted regarding the development of assessment and intervention measures relevant to the diverse learning disabled population in South Africa.

A Neglected Opportunity: Entrepreneurship Education in the Lower High School Curricula for Technology in South Africa and Botswana

Science.gov (United States)

du Toit, Adri; Gaotlhobogwe, Mike

2018-01-01

Technology is a school subject that forms part of the compulsory curriculum for high school learners in South Africa, and is a core theme in the subject Design and Technology in Botswana high schools. Knowledge and production skills acquired in the subject are applied to solve real-life problems consistent with the steps of the design process. The…

Spread F bubbles - Nonlinear Rayleigh-Taylor mode in two dimensions

Science.gov (United States)

Hudson, M. K.

1978-01-01

The paper discusses long-wavelength developed bottomside spread F which has been attributed to the Rayleigh-Taylor instability. The nonlinear saturation amplitude and the k spectrum of the inertia-dominated Rayleigh-Taylor instability is found in two directions: east-west and vertical. As in the collisional case (Chaturvedi and Ossakow, 1977), the dominant nonlinearity is found to be two-dimensional. It is found that the linearly most unstable modes, which are primarily horizontal, saturate by the nonlinear generation of vertical spatial harmonics. The harmonics are damped by diffusion or recombination. The resulting amplitude spectrum indicates that bubbles are vertically elongated in both inertial and collisional regimes.

Observation of Rayleigh-Taylor-like structures in a laser-accelerated foil

International Nuclear Information System (INIS)

Whitlock, R.R.; Emery, M.H.; Stamper, J.A.; McLean, E.A.; Obenschain, S.P.; Peckerar, M.C.

1984-01-01

Laser-accelerated targets have been predicted to be subject to the Rayleigh-Taylor hydrodynamic instability. The development of the instability was studied by introducing mass thickness variations in foil targets and observing the development of the target nonuniformities by side-on flash x radiography. Observations were made of target structures and mass redistribution effects which resemble Rayleigh-Taylor bubbles and spikes, including not only advanced broadening of the spike tips on the laser-irradiated side of the foil but also projections of mass on the unirradiated side. The observations compare well with numerical simulations

78 FR 43751 - Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor

Science.gov (United States)

2013-07-19

... National Emergency With Respect to the Former Liberian Regime of Charles Taylor On July 22, 2004, by... regime of Charles Taylor pursuant to the International Emergency Economic Powers Act (50 U.S.C. 1701-1706... constituted by the actions and policies of former Liberian President Charles Taylor and other persons, in...

Wall Shear Rates in Taylor Vortex Flow

Czech Academy of Sciences Publication Activity Database

Sobolík, V.; Jirout, T.; Havlica, Jaromír; Kristiawan, M.

2011-01-01

Roč. 4, č. 3 (2011), s. 25-31 ISSN 1735-3572 Grant - others:ANR:(FR) ANR-08-BLAN-0184-01 Institutional research plan: CEZ:AV0Z40720504 Keywords : taylor-couette flow * electrodiffusion diagnostics * membrane reactors Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.jafmonline.net/modules/journal/journal_browse.php?EJjid=13

Using Visual Ethnography to Explore a Principal's Perceptions of Innovations Made in a South African Primary School

Science.gov (United States)

Steyn, G. M.

2013-01-01

This study investigates a South African principal's view of implementing invitational education (IE) as an example of a professional development programme (PD) within a particular school setting. Two types of literature inform this study: leadership supportive of school development and the invitational education approach to teaching and learning.…

Rayleigh-Taylor mixing with time-dependent acceleration

Science.gov (United States)

Abarzhi, Snezhana

2016-10-01

We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a time-dependent acceleration. The acceleration is a power-law function of time, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical regimes of self-similar RT mixing-acceleration-driven Rayleigh-Taylor-type and dissipation-driven Richtymer-Meshkov-type with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with time-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

The Causes of Late Coming among High School Students in Soshanguve, Pretoria, South Africa

Directory of Open Access Journals (Sweden)

Simeon Maile

2017-12-01

Full Text Available Late coming to school has become a major problem in many schools, particularly township schools with serious consequences. Current research has demonstrated that many schools in South Africa are performing badly due to inefficient use of the teaching and learning time. In this article, we argue that while major administrative interventions are undertaken to improve the quality of learning and teaching, it seems that very little attention is paid to late-coming. Late-coming has become a cancer that saps away big interventions and strays the performance of selected township schools in a different direction. The purpose of this research is to investigate the causes of late-coming among high school students in selected secondary schools of Shoshanguve. A qualitative approach was used to draw data from high school students in selected secondary schools of Shoshanguve. The findings reveal that late-coming is common among learners in selected secondary schools of Shoshanguve. It happens every day for varying reasons. We recommended practical solutions ranging from administrative improvement to learner behavioural change.

76 FR 43799 - Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor

Science.gov (United States)

2011-07-21

...--Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor #0; #0; #0... Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor On July 22... of Charles Taylor, pursuant to the International Emergency Economic Powers Act (50 U.S.C. 1701-1706...

Boundary effects and the onset of Taylor vortices

Science.gov (United States)

Rucklidge, A. M.; Champneys, A. R.

2004-05-01

It is well established that the onset of spatially periodic vortex states in the Taylor-Couette flow between rotating cylinders occurs at the value of Reynolds number predicted by local bifurcation theory. However, the symmetry breaking induced by the top and bottom plates means that the true situation should be a disconnected pitchfork. Indeed, experiments have shown that the fold on the disconnected branch can occur at more than double the Reynolds number of onset. This leads to an apparent contradiction: why should Taylor vortices set in so sharply at the Reynolds number predicted by the symmetric theory, given such large symmetry-breaking effects caused by the boundary conditions? This paper offers a generic explanation. The details are worked out using a Swift-Hohenberg pattern formation model that shares the same qualitative features as the Taylor-Couette flow. Onset occurs via a wall mode whose exponential tail penetrates further into the bulk of the domain as the driving parameter increases. In a large domain of length L, we show that the wall mode creates significant amplitude in the centre at parameter values that are O( L-2) away from the value of onset in the problem with ideal boundary conditions. We explain this as being due to a Hamiltonian Hopf bifurcation in space, which occurs at the same parameter value as the pitchfork bifurcation of the temporal dynamics. The disconnected anomalous branch remains O(1) away from the onset parameter since it does not arise as a bifurcation from the wall mode.

Identification of Dynamic Loads Based on Second-Order Taylor-Series Expansion Method

OpenAIRE

Li, Xiaowang; Deng, Zhongmin

2016-01-01

A new method based on the second-order Taylor-series expansion is presented to identify the structural dynamic loads in the time domain. This algorithm expresses the response vectors as Taylor-series approximation and then a series of formulas are deduced. As a result, an explicit discrete equation which associates system response, system characteristic, and input excitation together is set up. In a multi-input-multi-output (MIMO) numerical simulation study, sinusoidal excitation and white no...

Search for Rayleigh-Taylor instability in laser irradiated layered thin foil targets

International Nuclear Information System (INIS)

Kilkenny, J.D.; Hares, J.D.; Rumsby, P.T.

1980-01-01

An experiment to measure the Rayleigh-Taylor instability at the vacuum-ablation surface of laser irradiated layered targets by time resolved x-ray spectroscopy is described. The time taken to burn through a layer of material is measured to be the same for massive targets as for thin foil accelerating targets. It is inferred that the thin foil targets might be Rayleigh-Taylor stable despite the values of γtauapproximately equal to15 calculated from classical theory. (author)

An Investigation of Ethnic Differences in the Motivation and Strategies for Learning of Students in Desegregated South African Schools.

Science.gov (United States)

Watkins, David; McInerney, Dennis; Akande, Adebowale; Lee, Clement

2003-01-01

Compared school motivation and use of deep processing (an indicator of learning quality) among black and white South African students from two recently integrated secondary schools. Student surveys found no significant ethnic group differences. Both groups considered working hard and having interest in school tasks to be more important than…

Effect of weak geometrical forcing on the stability of Taylor-vortex flow

International Nuclear Information System (INIS)

Pan Xiaolong; Khayat, Roger E

2008-01-01

Linear stability analysis of fully developed axisymmetric steady and spatially modulated Taylor-Couette flow is carried out in the narrow-gap limit. The inner cylinder is sinusoidally modulated and rotating, while the outer cylinder is straight and at rest. The modulation amplitude is assumed to be small, and the base steady flow is determined using a regular perturbation expansion of the flow field coupled to a variable-step finite-difference scheme. The disturbance flow equations are derived within the framework of Floquet theory and solved using a nonlinear two-point boundary-value approach. In contrast to unforced Taylor-Couette flow, only vortical base flow is possible in the forced case. It is found that the forcing tends to generally destabilize the base flow, especially around the critical point. Both the critical Taylor number and wavenumber are found to decrease essentially linearly with modulation amplitude.

Effect of magnetic field on Rayleigh-Taylor instability of two superposed fluids

International Nuclear Information System (INIS)

Sharma, P K; Tiwari, Anita; Chhajlani, R K

2012-01-01

The effect of two dimensional magnetic field on the Rayleigh-Taylor (R-T) instability in an incompressible plasma is investigated to include simultaneously the effects of suspended particles and the porosity of the medium. The relevant linearized perturbation equations have been solved. The explicit expression of the linear growth rate is obtained in the presence of fixed boundary conditions. A stability criterion for the medium is derived and discussed the Rayleigh Taylor instabilities in different configurations. It is found that the basic Rayleigh-Taylor instability condition is modified by the presence of magnetic field, suspended particles and porosity of the medium. In case of an unstable R-T configuration, the magnetic field has a stabilizing effect on the system. It is also found that the growth rate of an unstable R-T mode decreases with increasing relaxation frequency thereby showing a stabilizing influence on the R-T configuration.

Reliability, validity and description of timed performance of the Jebsen-Taylor Test in patients with muscular dystrophies.

Science.gov (United States)

Artilheiro, Mariana Cunha; Fávero, Francis Meire; Caromano, Fátima Aparecida; Oliveira, Acary de Souza Bulle; Carvas, Nelson; Voos, Mariana Callil; Sá, Cristina Dos Santos Cardoso de

2017-12-08

The Jebsen-Taylor Test evaluates upper limb function by measuring timed performance on everyday activities. The test is used to assess and monitor the progression of patients with Parkinson disease, cerebral palsy, stroke and brain injury. To analyze the reliability, internal consistency and validity of the Jebsen-Taylor Test in people with Muscular Dystrophy and to describe and classify upper limb timed performance of people with Muscular Dystrophy. Fifty patients with Muscular Dystrophy were assessed. Non-dominant and dominant upper limb performances on the Jebsen-Taylor Test were filmed. Two raters evaluated timed performance for inter-rater reliability analysis. Test-retest reliability was investigated by using intraclass correlation coefficients. Internal consistency was assessed using the Cronbach alpha. Construct validity was conducted by comparing the Jebsen-Taylor Test with the Performance of Upper Limb. The internal consistency of Jebsen-Taylor Test was good (Cronbach's α=0.98). A very high inter-rater reliability (0.903-0.999), except for writing with an Intraclass correlation coefficient of 0.772-1.000. Strong correlations between the Jebsen-Taylor Test and the Performance of Upper Limb Module were found (rho=-0.712). The Jebsen-Taylor Test is a reliable and valid measure of timed performance for people with Muscular Dystrophy. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Liz Taylor : minu van Gogh pole natsidele kuulunud

Index Scriptorium Estoniae

2004-01-01

Elizabeth Taylor palus kohtult otsust, et talle kuuluvat 15 miljonit dollarit maksvat Vincent van Goghi maali "Vaade Saint-Remy varjupaigale" pole natsid Margarete Mauthneri juudiperekonna käest vägivaldselt ära võtnud. E. Taylori isa ostis maali 1963. a. Londonis oksjonilt

Taylor vortices in the flow between two coaxial cylinders one of which has a step change in radius

International Nuclear Information System (INIS)

Raju, V R K

2014-01-01

A numerical study of the flow between two coaxial cylinders, where one of the cylinders has a step change in radius, is carried out. The inner cylinder rotates and the outer cylinder is stationary. Computation is restricted to axisymmetric motion since instability in flow between coaxial cylinders is found to first occur in the form of axisymmetric Taylor vortices. In the presence of a step, Taylor vortices are found to appear first in the region where the gap between the cylinders is larger and approximately when the local Taylor number in this region reaches the critical Taylor number for onset of instability. Subsequently, Taylor vortices appear in the region where the gap is narrower, and when the local Taylor number in that region exceeds the critical Taylor number. The Taylor vortices have inward flow at a stationary end plate, and outward flow at an end plate which rotates with the same angular velocity as the inner cylinder. Similar results were obtained by Sprague et al (2008 Phys. Fluids 20 014102) for a step on inner cylinder configuration. The step functions as another end plate, if the step size is large. Whereas, it has no effect, if the step size is small. In most situations, these determine whether the number of Taylor vortices in the wide and narrow gap regions is even or odd. When the end plates rotate synchronously, but at a different speed from the inner cylinder, a change from even to odd or odd to even number of vortices in each region occurs at certain rotation rates of the end plates by sudden appearance or disappearance of a vortex at the end of the column. For a certain range of rotation rates of the end plates, the total number of vortices in the entire fluid column is odd, although the end conditions are symmetrical. (paper)

Lead in drinking water: sampling in primary schools and preschools in south central Kansas.

Science.gov (United States)

Massey, Anne R; Steele, Janet E

2012-03-01

Studies in Philadelphia, New York City, Houston, Washington, DC, and Greenville, North Carolina, have revealed high lead levels in drinking water. Unlike urban areas, lead levels in drinking water in suburban and rural areas have not been adequately studied. In the study described in this article, drinking water in primary schools and preschools in five suburban and rural south central Kansas towns was sampled to determine if any exceeded the U.S. Environmental Protection Agency (U.S. EPA) guidance level for schools and child care facilities of 20 parts per billion (ppb). The results showed a total of 32.1% of the samples had detectable lead levels and 3.6% exceeded the U.S. EPA guidance level for schools and child care providers of 20 ppb. These results indicate that about one-third of the drinking water consumed by children age six and under in the five suburban and rural south central Kansas towns studied has some lead contamination, exposing these children to both short-term and long-term health risks. The authors suggest a need for increased surveillance of children's drinking water in these facilities.

Reading comprehension in South African schools: Are teachers getting it, and getting it right?

Directory of Open Access Journals (Sweden)

Pretorius, Elizabeth J.

2016-05-01

Full Text Available Much research exists about South African learners’ low literacy and numeracy levels and about poorly performing schools. In contrast, there are far fewer detailed descriptions of instructional practices and what teachers are actually doing in their classrooms, and far less evidence exists of in-depth research attempts to understand in what way and why teachers may experience problems with the teaching of reading literacy, particularly reading comprehension. This article aims to contribute to narrowing that gap by reviewing recent South African research on classroom comprehension instruction and obtaining information from teachers about how they perceive themselves as readers, what their teaching context is, what they claim to be doing about reading in their classrooms, and to match these responses with ANA results at their schools. Data were obtained through a quantitative questionnaire from 159 teachers at 30 schools across three provinces. The results show that many teachers are not themselves immersed in rich reading practices, many teachers claim to be doing more than is reflected in their schools’ literacy results, and in general teachers don’t seem to have a clear understanding of reading concepts, reading development and reading methodology.

Predictability of Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Viecelli, J.A.

1986-01-01

Numerical experiments modeling the Rayleigh Taylor instability are carried out using a two-dimensional incompressible Eulerian hydrodynamic code VFTS. The method of integrating the Navier-Stokes equations including the viscous terms is similar to that described in Kim and Moin, except that Lagrange particles have been added and provision for body forces is given. The Eulerian method is 2nd order accurate in both space and time, and the Poisson equation for the effective pressure field is solved exactly at each time step using a cyclic reduction method. 3 refs., 3 figs

Perceptions of Student Misconduct, Perceived Respect for Teachers, and Support for Corporal Punishment among School Teachers in South Korea: An Exploratory Case Study

Science.gov (United States)

Brown, Ben

2009-01-01

This article provides an analysis of survey data on perceptions of student misconduct, perceived respect for teachers, and support for corporal punishment among school teachers in South Korea. The data were gathered from a survey of 110 middle and high school teachers in Gyeonggi Province, South Korea. Descriptive, chi square, logistic regression,…

A State-Wide Survey of South Australian Secondary Schools to Determine the Current Emphasis on Ergonomics and Computer Use

Science.gov (United States)

Sawyer, Janet; Penman, Joy

2012-01-01

This study investigated the pattern of teaching of healthy computing skills to high school students in South Australia. A survey approach was used to collect data, specifically to determine the emphasis placed by schools on ergonomics that relate to computer use. Participating schools were recruited through the Department for Education and Child…

Addressing Gender Violence among Children in the Early Years of Schooling: Insights from Teachers in a South African Primary School

Science.gov (United States)

Mayeza, Emmanuel; Bhana, Deevia

2016-01-01

This paper explores how teachers in a poor township primary school in South Africa construct meaning regarding gender violence among children, and how they talk about addressing that violence. The paper argues that major influences on the endemic violence include complex societal structures that are inscribed with cultures of violent…

Food Availability in School Stores in Seoul, South Korea after Implementation of Food- and Nutrient-Based Policies

Science.gov (United States)

Choi, Seul Ki; Frongillo, Edward A.; Blake, Christine E.; Thrasher, James F.

2017-01-01

Background: To improve school store food environments, the South Korean government implemented 2 policies restricting unhealthy food sales in school stores. A food-based policy enacted in 2007 restricts specific food sales (soft drinks); and a nutrient-based policy enacted in 2009 restricts energy-dense and nutrient-poor (EDNP) food sales. The…

Performance of newly implemented Environmental Management Systems in primary schools in South Africa.

Science.gov (United States)

Hens, Luc; Wiedemann, Torsten; Raath, Schalk; Stone, Riana; Renders, Paul; Craenhals, Eric

2010-01-01

Quantitative results from Environmental Management Systems (EMS) at primary schools have rarely been examined in literature. This paper presents the monitoring results of environmental care in 39 primary schools in Northern South Africa. During 2 years, after the EMS was implemented in the curriculum and in the school's management, the progress of environmental performances of the participating schools has been measured, by means of detailed questionnaires, related to four environmental aspects: water, waste, energy and greening. At the beginning of the project, 50% of the schools performed well on water-related environmental actions. Two years later it was 76%. For waste-related activities the improvement was even stronger: from 50% to 100%. The environmental performances of the schools improved also for greening-related actions, from 50% at the start of the project to 64% two years later. Only energy-related activities did not improve significantly with only 24% of all schools performing well at the end of the survey period. In general, the introduction of an EMS succeeded in an improvement of the overall environmental performances of the schools, but cost-intensive activities were less successful than others. Copyright 2009 Elsevier Ltd. All rights reserved.

Taylorism, Tylerism, and Performance Indicators: Defending the Indefensible?

Science.gov (United States)

Helsby, Gill; Saunders, Murray

1993-01-01

Explores the antecedents to the growing interest in the use of educational performance indicators. Discusses this issue in relation to the work of economist F. W. Taylor and evaluator Ralph Tyler. Describes a five-year project that demonstrates the promise of teacher-developed performance indicators. (CFR)

Taylor dispersion of colloidal particles in narrow channels

NARCIS (Netherlands)

Sane, J.; Padding, J.T.; Louis, A.A.

2015-01-01

Special issue in Honor of Jean-Pierre Hansen We use a mesoscopic particle-based simulation technique to study the classic convection-diffusion problem of Taylor dispersion for colloidal discs in confined flow. When the disc diameter becomes non-negligible compared to the diameter of the pipe, there

On the validity of Taylor's hypothesis for wall-bounded flows

International Nuclear Information System (INIS)

Piomelli, U.; Balint, J.; Wallace, J.M.

1989-01-01

The results of large eddy simulation (LES) of the Navier--Stokes equations are used to evaluate the validity of Taylor's hypothesis of frozen turbulence, which states that the time derivative of some instantaneous quantity is proportional to its derivative in the streamwise direction, for incompressible plane channel flow. Time and space derivatives in the streamwise direction of the velocity components are, in fact, found to be well correlated. Root-mean-square fluctuations of the terms in Taylor's hypothesis also support the validity of this hypothesis above the buffer layer. The good agreement between LES and experimental results indicates that errors in the evaluation of derivatives in the streamwise direction are due mostly to insufficient resolution

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Boden, Stephan [Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Fluid Dynamics, P.O. Box 510119, Dresden (Germany); Santos Rolo, Tomy dos; Baumbach, Tilo [Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS), Eggenstein-Leopoldshafen (Germany); Hampel, Uwe [Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Fluid Dynamics, P.O. Box 510119, Dresden (Germany); Technische Universitaet Dresden (TUD), AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering, Dresden (Germany)

2014-07-15

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-μm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations. (orig.)

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

Science.gov (United States)

Boden, Stephan; dos Santos Rolo, Tomy; Baumbach, Tilo; Hampel, Uwe

2014-07-01

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-µm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations.

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

International Nuclear Information System (INIS)

Boden, Stephan; Santos Rolo, Tomy dos; Baumbach, Tilo; Hampel, Uwe

2014-01-01

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-μm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations. (orig.)

The Contribution of F.W. Taylor to Industrial and Organizational Psychology

Directory of Open Access Journals (Sweden)

E. C. Thomas

1982-11-01

In die artikel word getoon dat F.W. Taylor die erkende "vader van wetenskaplike bestuur" ook erkenning behoort te geniet as grondlegger van die Bedryf en -organisasiesielkunde. Sy werk op die terreine van prestasiemotivering en tevredenheid, opleiding, plasing van werkers, bestuurs- en organisasieontwikkeling en arbeidsverhoudinge het waarskynlik die werk van erkende sielkundiges op hierdie gebiede vooruitgeloop, of grondslag daarvoor gelê. Daar word tot die slotsom gekom dat alhoewel Taylor nie 'n opgeleide sielkundige was nie, hy en sy kollegas erkenning moet kry vir die praktiese implimentering van die beginsels en teorieë van die moderne Bedryf- en Organisasiesielkunde.

Taylor Series Trajectory Calculations Including Oblateness Effects and Variable Atmospheric Density

Science.gov (United States)

Scott, James R.

2011-01-01

Taylor series integration is implemented in NASA Glenn's Spacecraft N-body Analysis Program, and compared head-to-head with the code's existing 8th- order Runge-Kutta Fehlberg time integration scheme. This paper focuses on trajectory problems that include oblateness and/or variable atmospheric density. Taylor series is shown to be significantly faster and more accurate for oblateness problems up through a 4x4 field, with speedups ranging from a factor of 2 to 13. For problems with variable atmospheric density, speedups average 24 for atmospheric density alone, and average 1.6 to 8.2 when density and oblateness are combined.

Knowledge and Practice of Sun Protection in Schools in South Africa Where No National Sun Protection Programme Exists

Science.gov (United States)

Wright, Caradee Y.; Reeder, Anthony I.; Albers, Patricia N.

2016-01-01

Interventions in primary schools that increase sun-protective behaviours and decrease ultraviolet radiation exposure, sunburn incidence and skin cancer risk can be effective. SunSmart School Accreditation Programmes (SSAP) are recommended. Prior to SSAP implementation in South Africa, we explored the feasibility of obtaining national baseline…

THE INCORPORATION OF THE USA ‘SCIENCE MADE SENSIBLE’ PROGRAM IN SOUTH AFRICAN PRIMARY SCHOOLS: A CROSS-CULTURAL APPROACH TO SCIENCE EDUCATION

Directory of Open Access Journals (Sweden)

Rian de Villiers

2016-02-01

Full Text Available The Science Made Sensible (SMS program began as a partnership between the University of Miami (UM, Florida, USA, and some public schools in Miami. In this program, postgraduate students from UM work with primary school science teachers to engage learners in science through the use of inquiry-based, hands-on activities. Due to the success of the SMS program in Miami, it was extended internationally. The SMS team (two Miami Grade 6/7 science teachers and two UM postgraduate students, 195 learners, and five South African teachers at two primary schools in Pretoria, South Africa, participated in this study. A quantitative research design was employed, and learners, teachers and UM postgraduate students used questionnaires to evaluate the SMS program. The results show that the SMS team was successful in reaching the SMS goals in these South African schools. More than 90% of the learners are of opinion that the SMS team from the USA made them more interested in the natural sciences and fostered an appreciation for the natural sciences. All the South African teachers plan to adopt and adapt some of the pedagogical strategies they learned from the SMS team. This article includes a discussion about the benefits of inquiry-based learning and the similarities and dissimilarities of USA and South Africa’s teaching methods in the science classrooms.

SHIFTING THE FUTURE? TEACHERS AS AGENTS OF SOCIAL CHANGE IN SOUTH AFRICAN SECONDARY SCHOOLS

Directory of Open Access Journals (Sweden)

Christina Lane Cappy

2016-12-01

Full Text Available South Africa has risen to the forefront of educational debates that claim schooling can promote social justice and social cohesion. By drawing on Freire’s (1970 theory of critical pedagogy, this paper examines how South African teachers in rural and township schools encourage students to reflect critically upon their own lives and take action to improve issues of inequality, violence, and insecurity. It argues that teachers understand their roles as agents of social change primarily as encouraging respect, morality, and racial reconciliation among learners. The ways in which the youth take up the teachers’ efforts to promote change depends upon how the teachers’ practices speak to the students’ own life circumstances. When the youth relate to the teachers’ life stories and course material, they engage in the process of moral translation. In other words, the youth rework their lessons into ideas of how they should behave as moral human beings. Yet, frequently young South Africans do not learn a morality based on a Freirean notion of social justice – a seemingly central component to the national curriculum – but instead a morality based on individualised notions of personal responsibility and hope for a better future. The paper concludes with several suggestions to improve educational practices for social justice.

School Leadership and Management in South Africa: Findings from a Systematic Literature Review

Science.gov (United States)

Bush, Tony; Glover, Derek

2016-01-01

Purpose: The purpose of this paper is to provide a systematic review of the literature on school leadership and management in South Africa, linked to the 20th anniversary of democratic government and integrated education. Design/Methodology/Approach: The authors conducted a systematic review of all published work since 2007 with a more selective…

Insulin diffusion and self-association characterized by real-time UV imaging and Taylor dispersion analysis

DEFF Research Database (Denmark)

Jensen, Sabrine S; Jensen, Henrik; Cornett, Claus

2014-01-01

, self-association, and apparent size of insulin were further characterized by Taylor dispersion analysis, size exclusion chromatography, and dynamic light scattering. At low insulin concentrations and pH 3.0, the hydrodynamic radius of insulin was determined by Taylor dispersion analysis to 1.5±0.1nm...

First Steps to School Readiness: South Carolina's Response to At-Risk Early Childhood Population.

Science.gov (United States)

Buford, Rhonda; Stegelin, Dolores A.

2003-01-01

Describes South Carolina's new state early childhood program, First Steps to School Readiness. Includes a profile of the state's at-risk child population, noting poverty and education risk indicators, and describing key program components. The article discusses program oversight, local program partnerships, program funding mechanisms, and local…

Revisiting the roles and responsibilities of speech-language therapists in South African schools.

Science.gov (United States)

Wium, A M; Louw, B

2013-12-01

The role of speech-language therapists (SLTs) in schools in South Africa needs to be revisited based on the changing educational needs in the country. This article builds on a paper by Kathard et al. (2011), which discussed the changing needs of the country with regard to the role of SLTs working in schools. South African policy changes indicated a shift from supporting the child to supporting the teacher, but also place more emphasis on the support of all learners in literacy in an effort to address past inequities. This paper addresses several of the questions that emerged from Kathard et al. and explores the collaborative roles played by SLTs on four levels in the education context. Collaboration at the learner level (level 1) focuses on prevention and support, whereas collaboration at the teacher level (level 2) is described in terms of training, mentoring, monitoring and consultation. Collaboration can also occur at the district level (level 3), where the focus is mainly on the development and implementation of support programmes for teachers in areas of literacy and numeracy. Collaboration at the level of national and provincial education (level 4) is key to all other roles, as it impacts on policy. This last level is the platform to advocate for the employment of SLTs in schools. Such new roles and responsibilities have important implications for the preparation of future SLTs. Suggestions for curricular review and professional development are discussed. It is proposed that SASLHA responds to the changes by developing a position statement on the roles and responsibilities of SLTs in schools.

The representation of women in a sample of post-1994 South African school History textbooks

Directory of Open Access Journals (Sweden)

Sonja Schoeman

2009-11-01

Full Text Available History curriculum revisions post 1994 were followed by a range of new History textbooks intended to meet the needs of teachers seeking to implement the revised curriculum. I sought to establish whether or not a sample of these textbooks had built upon the gender equality initiatives introduced after 1994. A qualitative intrinsic case study was conducted to determine the extent of the representation of women in three South African school History textbooks. The results demonstrated that, despite the introduction of gender equality initiatives, in the sample selected the role of men in history continued to receive emphasis. In South African history men have indeed been more prominent than women, and have been viewed as the decision-makers, yet there is room in standard South African History textbooks for the inclusion of the ordinary daily events in which women participated or through which they exercised an influence on decision- making by men. Shepherd's media literacy curriculum model, incorporating the Department of Education's approaches to critical media education, is proposed as a tool to empower in-service History teachers to teach learners to deconstruct patriarchal or hegemonic power relations in school History textbooks.

Effect of magnetic field on the Rayleigh Taylor instability of rotating and stratified plasma

International Nuclear Information System (INIS)

Sharma, PK; Tiwari, Anita; Argal, Shraddha

2017-01-01

In the present study the effect of magnetic field and rotation have been carried out on the Rayleigh Taylor instability of conducting and rotating plasma, which is assumed to be incompressible and confined between two rigid planes z = 0 and z = h. The dispersion relation of the problem is obtained by solving the basic MHD equations of the problem with the help normal mode technique and appropriate boundary conditions. The dispersion relation of the medium is analysed and the effect of magnetic field and angular velocity (rotation effect) have been examined on the growth rate of Rayleigh Taylor instability. It is found that the magnetic field and angular velocity (rotation effect) have stabilizing influence on the Rayleigh Taylor instability. (paper)

Modeling Taylor series approximations for prompt neutron kinetics with lab view simulations

International Nuclear Information System (INIS)

Adzri, E. P.

2012-09-01

The reactor point kinetics equations have been subjected to intense research in an effort to find simple yet accurate numerical solutions methods. The equations are very stiff numerically, meaning that there is a wide variation in the decay constants, so that using a particular time step in the numerical solution may provide sufficient accuracy for the group, but not for another. Several solutions techniques have been presented on the point kinetics equations with varying degrees of complexity. These include Power Series Solutions, CORE, PCA, Genapol and Taylor series methods. In this research, algorithms were developed based on the first and second order Taylor series expansion and simulated in LabVIEW to solve the Reactor Point Kinetics equations using block diagram nodes implemented within stacked sequences. The algorithms developed were fast,accurate and simple to code. Several reactivity insertions were used to simulate the change in neutron population with time. The LabVIEW- Taylor series solutions were compared with other solution techniques such as Power Series Solutions, CORE, PCA, Genapol and McMahon and Pierson's Taylor series approximation. The results of LabVIEW-Taylor series technique used by McMahon and Pearson The LabVIEW-implemented techniques were found to agree very well with these other methods. At 1x10 -8 s the neutron population was 1.000220 neutrons / cm 3 , at 1 x 10 -2 s it was 2.007681 neutrons / cm 3 and at 1x10 -1 s it was 2.075317 neutrons / cm 3 ; same results reported by Genapol for a fast reactor, it produced good and accurate results and compared very favorably with other methods found in the literature. Using much smaller time steps to the order or 10 -8 s commensurate with fast reactor parameters also produced very satisfactory results, indicating that the LabVIEW-based Taylor series technique is suitable for simulating the kinetics of fast reactors as well as thermal reactors. Algorithms developed that included second order terms

Rayleigh-Taylor mixing with space-dependent acceleration

Science.gov (United States)

Abarzhi, Snezhana

2016-11-01

We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a space-dependent acceleration. The acceleration is a power-law function of space coordinate, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical sub-regimes of self-similar RT mixing - the acceleration-driven Rayleigh-Taylor-type mixing and dissipation-driven Richtymer-Meshkov-type mixing with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with space-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

Failure to Thrive? The Community Literacy Strand of the Additive Bilingual Project at an Eastern Cape Community School, South Africa

Science.gov (United States)

Hunt, George

2007-01-01

This paper discusses an attempt to establish community literacy procedures in an Eastern Cape community school. The school hosts the Additive Bilingual Education (ABLE) project, a cooperation between UK and South African universities and the school trust. The community literacy strand of the project encourages family members to contribute oral…

Assessment of learners' exposure to health education and promotion at school in the Limpopo Province of South Africa.

Science.gov (United States)

Tosin, Oni H; Tshitangano, Takalani G

2016-06-30

School participation and educational attainment among adolescents have been rising rapidly in the developing world. Thus, to attain Millennium Development Goal 6 (Combat HIV and/or AIDs, malaria and other diseases), it is crucial to seize the opportunity to educate and encourage teenagers about healthy choices and proper social behaviours that will continue into adulthood. This study aimed to assess the exposure of rural secondary school learners to health education and promotion at schools in the Limpopo Province of South Africa. This study was carried out at 10 secondary schools in Vhumbedzi educational circuit. The study adopted a cross-sectional quantitative approach. Data were collected from 338 randomly selected learners from 10 secondary schools that make up a rural Vhumbedzi circuit in the Limpopo province. A self-administered questionnaire was used to collect data. The findings showed that, 102 (66.07%) male and 121 (67.60%) female learners reported that they were taught about physical changes that occur during adolescence. In the same vein, most of the participants (n = 128, 84.39%) and (n = 152, 85.39%) males and females respectively claimed to have been taught about sexually transmitted diseases. In this study the secondary schools in the Limpopo Province of South Africa are making efforts to uphold and expose their learners to health education and promotion at school.Keyword: Health education and promotion, adolescents, school, learners.

Using Taylor Expansions to Prepare Students for Calculus

Science.gov (United States)

Lutzer, Carl V.

2011-01-01

We propose an alternative to the standard introduction to the derivative. Instead of using limits of difference quotients, students develop Taylor expansions of polynomials. This alternative allows students to develop many of the central ideas about the derivative at an intuitive level, using only skills and concepts from precalculus, and…

Educators' disciplinary capabilities after the banning of corporal punishment in South African schools

Directory of Open Access Journals (Sweden)

Cosmas Maphosa

2010-01-01

Full Text Available The escalation of learner indiscipline cases in schools suggests failure by teachers to institute adequate alternative disciplinary measures after corporal punishment was outlawed in South African schools. We sought to address the following two research questions: (a How do educators view their disciplinary capabilities in the post-corporal punishment period? and (b How do educators view the usefulness of alternative disciplinary measures? The study adopted a qualitative approach. A case study of three purposively selected practising junior secondary school educators was used. Data were collected through interviews. We found that educators generally feel disempowered in their ability to institute discipline in schools in the absence of corporal punishment. Educators revealed that learners do not fear or respect educators because they know that nothing will happen to them. Although educators are aware of alternative disciplinary measures, they view them as ineffective and time consuming.

Childrens engagements with violence : a study in a South African school

OpenAIRE

Parkes, Jenny

2005-01-01

This thesis is an account of a qualitative study which set out to explore the meanings for children of living with violence. Using a social constructionist epistemology, I examine how, through social relationships, children (co-)construct beliefs, values and practices in relation to violence, and consider the implications for violence prevention. Set in the changing context of post-apartheid South Africa, the study was located in a primary school in a township of Cape Town, whe...

Taylor dispersion on a fractal

International Nuclear Information System (INIS)

Mazo, R.M.

1998-01-01

Taylor dispersion is the greatly enhanced diffusion in the direction of a fluid flow caused by ordinary diffusion in directions orthogonal to the flow. It is essential that the system be bounded in space in the directions orthogonal to the flow. We investigate the situation where the medium through which the flow occurs has fractal properties so that diffusion in the orthogonal directions is anomalous and non-Fickian. The effective diffusion in the flow direction remains normal; its width grows proportionally with the time. However, the proportionality constant depends on the fractal dimension of the medium as well as its walk dimension. (author)

Education Resourcing in Post-Apartheid South Africa: The Impact of Finance Equity Reforms in Public Schooling: Research Article

Science.gov (United States)

Motala, Shireen

2006-01-01

Through an analysis of recent quantitative data on equity and school funding in South Africa, this article aims to explicate the patterns and typology of inequality in post-apartheid South Africa, and to deepen our understanding of the construct of equity. It also aims to understand the application of equity in the context of public schooling…

Study of three-dimensional Rayleigh--Taylor instability in compressible fluids through level set method and parallel computation

International Nuclear Information System (INIS)

Li, X.L.

1993-01-01

Computation of three-dimensional (3-D) Rayleigh--Taylor instability in compressible fluids is performed on a MIMD computer. A second-order TVD scheme is applied with a fully parallelized algorithm to the 3-D Euler equations. The computational program is implemented for a 3-D study of bubble evolution in the Rayleigh--Taylor instability with varying bubble aspect ratio and for large-scale simulation of a 3-D random fluid interface. The numerical solution is compared with the experimental results by Taylor

The Rights of the Child and "The Good of the Learners": A Comparative Ethnographical Survey on the Abolition of Corporal Punishment in South African Schools

Science.gov (United States)

Payet, Jean-Paul; Franchi, Vije

2008-01-01

In contemporary South Africa, the abolition of corporal punishment symbolizes a break with the previous schooling system. A qualitative study in four formerly segregated schools south of Johannesburg showcases different realities and discourses on corporal punishment. The practices vary from its total abolition to its continued maintenance. Most…

Beryllium-10 in the Taylor Dome ice core: Applications to Antarctic glaciology and paleoclimatology

Energy Technology Data Exchange (ETDEWEB)

Steig, E.J.

1996-12-31

An ice core was drilled at Taylor dome, East Antarctica, reaching to bedrock at 554 meters. Oxygen-isotope measurements reveal climatic fluctuations through the last interglacial period. To facilitate comparison of the Taylor Dome paleoclimate record with geologic data and results from other deep ice cores, several glaciological issues need to be addressed. In particular, accumulation data are necessary as input for numerical ice-flow-models, for determining the flux of chemical constituents from measured concentrations, and for calculation of the offset in age between ice and trapped air in the core. The analysis of cosmogenic beryllium-10 provides a geochemical method for constraining the accumulation-rate history at Taylor Dome. High-resolution measurements were made in shallow firn cores and snow pits to determine the relationship among beryllium-10 concentrations, wet and dry deposition mechanisms, and snow-accumulation rates. Comparison between theoretical and measured variations in deposition over the last 75 years constrains the relationship between beryllium-10 deposition and global average production rates. The results indicate that variations in geomagnetically-modulated production-rate do not strongly influence beryllium-10 deposition at Taylor Dome. Although solar modulation of production rate is important for time scales of years to centuries, snow-accumulation rate is the dominant control on ice-core beryllium-10 concentrations for longer periods. Results show that the Taylor Dome core can be used to provide new constraints on regional climate over the last 130,000 years, complementing the terrestrial and marine geological record from the Dry Valley, Transantarctic Mountains and western Ross Sea.

A classical approach to the restoration of discipline in South African schools

Directory of Open Access Journals (Sweden)

I.J. Oosthuizen

2003-08-01

Full Text Available As a result of the era of civil disobedience associated with the struggle for freedom and democracy discipline in many schools has deteriorated. The persistent lack of discipline in all South African schools can only be countered by means of a wise application of discipline. Application of “discipline” according to the standard dictionary meanings of the word will, however, not be appropriate since it implies a clamp-down on disruptive behaviour, including punishment, chastisement and retribution. Discipline associated with the paideia ideal of well-educatedness and of the educator as the servant of his learners (paidagogos, though within the context of a reformational perspective of discipline on the other hand, will be more suitable.

Measuring Nominal and Real Convergence of Selected CEE Countries by the Taylor Rule

Directory of Open Access Journals (Sweden)

Böing Tobias

2016-12-01

Full Text Available We propose using a simple Taylor rule to evaluate business cycle convergence of the Czech Republic, Hungary, and Poland with the Eurozone. Our findings indicate an ongoing convergence of those CEE countries to the Eurozone, but with instabilities and heterogeneity between the countries. Especially Poland has shown a high degree of convergence in recent years. But there are still relevant differences in Taylor rates of each country to the Eurozone of about two percentage points.

Liquidity Traps with Global Taylor Rules

OpenAIRE

Stephanie Schmitt-Grohe; Martin Uribe

2000-01-01

A key result of a recent literature that focuses on the global consequences of Taylor-type interest rate feedback rules is that such rules, in combination with the zero-bound on nominal interest rates, can lead to unintended liquidity traps. An immediate question posed by this result is whether the government could avoid liquidity traps by ignoring the zero-bound, that is, by threatening to set the nominal interest rate at a negative value should the inflation rate fall below a certain thresh...

Heat transfer characteristics of liquid-gas Taylor flows incorporating microencapsulated phase change materials

International Nuclear Information System (INIS)

Howard, J A; Walsh, P A

2014-01-01

This paper presents an investigation on the heat transfer characteristics associated with liquid-gas Taylor flows in mini channels incorporating microencapsulated phase change materials (MPCM). Taylor flows have been shown to result in heat transfer enhancements due to the fluid recirculation experienced within liquid slugs which is attributable to the alternating liquid slug and gas bubble flow structure. Microencapsulated phase change materials (MPCM) also offer significant potential with increased thermal capacity due to the latent heat required to cause phase change. The primary aim of this work was to examine the overall heat transfer potential associated with combining these two novel liquid cooling technologies. By investigating the local heat transfer characteristics, the augmentation/degradation over single phase liquid cooling was quantified while examining the effects of dimensionless variables, including Reynolds number, liquid slug length and gas void fraction. An experimental test facility was developed which had a heated test section and allowed MPCM-air Taylor flows to be subjected to a constant heat flux boundary condition. Infrared thermography was used to record high resolution experimental wall temperature measurements and determine local heat transfer coefficients from the thermal entrance point. 30.2% mass particle concentration of the MPCM suspension fluid was examined as it provided the maximum latent heat for absorption. Results demonstrate a significant reduction in experimental wall temperatures associated with MPCM-air Taylor flows when compared with the Graetz solution for conventional single phase coolants. Total enhancement in the thermally developed region is observed to be a combination of the individual contributions due to recirculation within the liquid slugs and also absorption of latent heat. Overall, the study highlights the potential heat transfer enhancements that are attainable within heat exchange devices employing MPCM

Policy commitments vs. lived realities of young pregnant women and mothers in school, Western Cape, South Africa.

Science.gov (United States)

Ngabaza, Sisa; Shefer, Tamara

2013-05-01

Reproductive rights in South Africa continue to be undermined for young women who fall pregnant and become mothers while still at school. Before 1994, exclusionary practices were common and the majority of those who fell pregnant failed to resume their education. With the adoption of new policies in 2007, young pregnant women and mothers are supposed to be supported to complete school successfully. Notwithstanding these new policies, there are incongruities between policy implementation and young women's lived experience in school. This paper explores the experiences of pregnancy and parenting among a group of 15 young women who fell pregnant and became mothers while attending three high schools in Khayelitsha township, a working-class community in the Western Cape of South Africa. Qualitative, in-depth interviews, conducted between 2007 and 2008, highlighted two key areas of concern: continuing exclusionary practices on the part of schools, based on conservative interpretations of policy, and negative and moralistic responses from teachers and peers. Such practices resulted in secrecy and shame about being pregnant, affecting the young women's emotional and physical well-being and their decisions whether to remain in school during pregnancy and return after having the baby. Further attention is required to ensure appropriate implementation of policies aimed at supporting pregnant and parenting young women to complete their education successfully. Copyright © 2013 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

The Bible and mission in faith perspective: J.Hudson Taylor and the early China Inland Mission

NARCIS (Netherlands)

Wigram, C.E.M.

2007-01-01

The thesis 'The Bible and Mission in Faith Perspective: J.Hudson Taylor and the Early China Inland Mission' by Christopher E.M. Wigram analysis the hermeneutical assumptions that underlay Hudson Taylor's approach to biblical interpretation, and the significance of his approach for the mission which

Teacher Knowledge of Attention Deficit Hyperactivity Disorder among Middle School Students in South Texas

Science.gov (United States)

Guerra, Fred R., Jr.; Brown, Michelle S.

2012-01-01

This quantitative study examined the knowledge levels middle school teachers in South Texas have in relation to attention deficit hyperactivity disorder (ADHD). The study specifically compared teacher knowledge levels among three specific ADHD knowledge areas: (a) general knowledge of ADHD, (b) knowledge of symptoms/diagnosis of ADHD, and (c)…

A crítica de Charles Taylor ao naturalismo na Ciência Política

Directory of Open Access Journals (Sweden)

Tiago Losso

2011-06-01

Full Text Available Os mais recentes esforços de revitalização do enfoque interpretativo na Ciência Política têm sua gênese na década de 1960, quando vários autores passaram a advogar a centralidade do estudo dos significados lingüístico e hermenêutico dos fenômenos políticos. Dentre tais autores, destaca-se o filósofo e politólogo Charles Taylor, cujos textos dos anos 1960 e 1970 desferem críticas contundentes ao naturalismo subjacente ao mainstream da Ciência Política da época. Meu objetivo é explorar a crítica de Taylor ao naturalismo, pensadas no contexto de uma proposta de abordagem interpretativa para a Ciência Política. Primeiramente, contextualizarei as contribuições de Taylor no âmbito mais amplo do interpretive turn nas Ciências Sociais. Em seguida, sumarizarei as reservas que Quentin Skinner e Clifford Geertz apresentam à crítica de Taylor.

Pediatric and adolescent applications of the Taylor Spatial Frame.

Science.gov (United States)

Paloski, Michael; Taylor, Benjamin C; Iobst, Christopher; Pugh, Kevin J

2012-06-01

Limb deformity can occur in the pediatric and adolescent populations from multiple etiologies: congenital, traumatic, posttraumatic sequelae, oncologic, and infection. Correcting these deformities is important for many reasons. Ilizarov popularized external fixation to accomplish this task. Taylor expanded on this by designing an external fixator in 1994 with 6 telescoping struts that can be sequentially manipulated to achieve multiaxial correction of deformity without the need for hinges or operative frame alterations. This frame can be used to correct deformities in children and has shown good anatomic correction with minimal morbidity. The nature of the construct and length of treatment affects psychosocial factors that the surgeon and family must be aware of prior to treatment. An understanding of applications of the Taylor Spatial Frame gives orthopedic surgeons an extra tool to correct simple and complex deformities in pediatric and adolescent patients. Copyright 2012, SLACK Incorporated.

Taylor-Made Education: The Influence of the Efficiency Movement on the Testing of Reading Skills.

Science.gov (United States)

Allen, JoBeth

Much of what has developed in the testing of reading harkens back to the days of the "Cult of Efficiency" movement in education that can be largely attributed to Frederick Winslow Taylor. Taylor spent most of his productive years studying time and motion in an attempt to streamline industrial production so that people could work as…

Rayleigh-Taylor instability in multi-structured spherical targets

International Nuclear Information System (INIS)

Gupta, N.K.; Lawande, S.V.

1986-01-01

An eigenvalue equation for the exponential growth rate of the Rayleigh-Taylor instability is derived in spherical geometry. The free surface and jump boundary conditions are obtained from the eigenvalue equation. The eigenvalue equation is solved in the cases where the initial fluid density profile has a step function or exponential variation in space and analytical formulae for growth rate of the instability are obtained. The solutions for the step function are generalized for any number N of spherical zones forming an arbitrary fluid density profile. The results of the numerical calculations for N spherical zones are compared with the exact analytical results for exponential fluid density profile with N=10 and a good agreement is observed. The formalism is further used to study the effects of density gradients on Rayleigh-Taylor instability in spherical geometry. Also analytical formulae are presented for a particular case of N=3 and shell targets. The formalism developed here can be used to study the growth of the instability in present day multi-structured shell targets. (author)

Nonlinear interaction of Rayleigh--Taylor and shear instabilities

International Nuclear Information System (INIS)

Finn, J.M.

1993-01-01

Results on the nonlinear behavior of the Rayleigh--Taylor instability and consequent development of shear flow by the shear instability [Phys. Fluids B 4, 488 (1992)] are presented. It is found that the shear flow is generated at sufficient amplitude to reduce greatly the convective transport. For high viscosity, the time-asymptotic state consists of an equilibrium with shear flow and vortex flow (with islands, or ''cat's eyes''), or a relaxation oscillation involving an interplay between the shear instability and the Rayleigh--Taylor instability in the presence of shear. For low viscosity, the dominant feature is a high-frequency nonlinear standing wave consisting of convective vortices localized near the top and bottom boundaries. The localization of these vortices is due to the smaller shear near the boundary regions. The convective transport is largest around these convective vortices near the boundary and there is a region of good confinement near the center. The possible relevance of this behavior to the H mode and edge-localized modes (ELM's) in the tokamak edge region is discussed

Female Sport Participation In South African Rural Schools: Analysis Of Socio-Cultural Constraints

Directory of Open Access Journals (Sweden)

Kubayi Ntwanano Alliance

2015-06-01

Full Text Available This study was carried out to examine constraints to sport participation among female secondary school students in Hlanganani rural area, Limpopo Province, South Africa. A total of 101 female students aged 17–24 years from four secondary schools were recruited to participate in the study. A self-administered questionnaire was used to collect data. Results indicated that the dress code, lack of energy, lack of family support and family commitment were identified as major constraints to sport participation among female students. The results of this study provide practical implications for promoting and developing female sports programmes in rural schools. This study suggests that stakeholders such as parents, peers, and teachers should motivate and encourage female students to participate in school sport. Additionally, the study recommended that in order to promote sport participation in rural areas, the values, norms, beliefs, attitudes and customs that restrict females from participating in sport and physical activity should be dissented.

Creating a school nutrition environment index and pilot testing it in elementary and middle schools in urban South Korea.

Science.gov (United States)

Park, Sohyun; Kwon, Kwang-Il; Kweon, Soon Ju; Wang, Youfa; Gittelsohn, Joel

2017-10-01

The role of a school's nutrition environment in explaining students' eating behaviors and weight status has not been examined in an Asian setting. The purpose of this study was to create a school nutrition environment index and to pilot test the index in elementary and middle schools in urban South Korea. This study used a mixed-methods approach. Environment assessment tools were developed based on formative research, which comprised literature reviews, in-depth interviews, and focus group discussions. Key elements from the formative research were included in the assessment tool, which consisted of a structured survey questionnaire for school dietitians. Fifteen school dietitians from 7 elementary and 8 middle schools in Seoul completed the questionnaire. The formative research revealed four main sections that guided a summary index to assess a school's nutrition environment: resource availability, education and programs, dietitians' perceptions and characteristics, and school lunch menu. Based on the literature reviews and interviews, an index scoring system was developed. The total possible score from the combined four index sections was 40 points. From the 15 schools participating in the pilot survey, the mean school nutrition-environment index was 22.5 (standard deviation ± 3.2; range 17-28). The majority of the schools did not offer classroom-based nutrition education or nutrition counseling for students and parents. The popular modes of nutrition education were school websites, posters, and newsletters. This paper illustrates the process used to develop an instrument to assess a school's nutrition environment. Moreover, it presents the steps used to develop a scoring system for creation of a school nutrition environment index. As pilot testing indicated the total index score has some variation across schools, we suggest applying this instrument in future studies involving a larger number of schools. Future studies with larger samples will allow investigation

Taylor Dispersion Analysis as a promising tool for assessment of peptide-peptide interactions

DEFF Research Database (Denmark)

Høgstedt, Ulrich B; Schwach, Grégoire; van de Weert, Marco

2016-01-01

solutions increased with concentration. Our results indicate that a viscosity difference between run buffer and sample in Taylor Dispersion Analysis may result in overestimation of the measured diffusion coefficient. Thus, Taylor Dispersion Analysis provides a practical, but as yet primarily qualitative......Protein-protein and peptide-peptide (self-)interactions are of key importance in understanding the physiochemical behavior of proteins and peptides in solution. However, due to the small size of peptide molecules, characterization of these interactions is more challenging than for proteins...

Autenticitet og kritisk sprogfællesskab hos Charles Taylor

DEFF Research Database (Denmark)

Crone, Manni

2002-01-01

Lever vi i individualistiske samfund, hvor autenticitet og selvrealisering er blevet de højeste værdier? Den canadiske kommunitarist Charles Taylor argumenterer for, at selv om autenticitet og selvrealisering er vigtige værdier for det moderne menneske, kan en excessiv individualisme alligevel...

The perceptions of parents of their role in the democratic governance of schools in South Africa: are they on board?

Directory of Open Access Journals (Sweden)

Vuzi Mncube

2009-02-01

Full Text Available I argue that parent participation in SGBs is an important ingredient in building democracy in the schooling system, as well as in the wider society of South Africa. At some schools in South Africa, parents are not yet playing their full role as governors mandated by legislation. Parents at some rural schools are reluctant to participate in the decision-making by School Governing Bodies (SGBs as a result of their low educational level or of power struggles in SGBs. In some former model C schools, on the other hand, lack of participation is related to a level of education of parents in general, lack of education on parental involvement in school activities, a fear of ‘academic victimisation' of their children, language barrier, and difficulty in attending meetings. This lack of involvement is at its highest in school governing bodies. It appears therefore that while representation and debate are theoretically open and fair, there are still factors that inhibit SGBs from operating democratically. Although the political control of apartheid has gone, issues related to full democratic participation have not been resolved.

Surfactants and the Rayleigh-Taylor instability of Couette type flows

Science.gov (United States)

Frenkel, A. L.; Halpern, D.; Schweiger, A. S.

2011-11-01

We study the Rayleigh-Taylor instability of slow Couette- type flows in the presence of insoluble surfactants. It is known that with zero gravity, the surfactant makes the flow unstable to longwave disturbances in certain regions of the parameter space; while in other parametric regions, it reinforces the flow stability (Frenkel and Halpern 2002). Here, we show that in the latter parametric sectors, and when the (gravity) Bond number Bo is below a certain threshold value, the Rayleigh-Taylor instability is completely stabilized for a finite interval of Ma, the (surfactant) Marangoni number: MaL Ma2. For Ma Ma2, and also for MaL Ma2 as functions of the Bond number. We note that (for an interval of the Bond number) there are two distinct criticalities with nonzero (and distinct) critical wavenumbers.

Quantitative investigation of the transition process in Taylor-Couette flow

International Nuclear Information System (INIS)

Tu, Xin Cheng; Kim, Hyoung Bum Kim; Liu, Dong

2013-01-01

The transition process from circular Couette flow to Taylor vortex flow regime was experimentally investigated by measuring the instantaneous velocity vector fields at the annular gap flow region between two concentric cylinders. The proper orthogonal decomposition method, vorticity calculation, and frequency analysis were applied in order to analyze the instantaneous velocity fields to identify the flow characteristics during the transition process. From the results, the kinetic energy and corresponding reconstructed velocity fields were able to detect the onset of the transition process and the alternation of the flow structure. The intermittency and oscillation of the vortex flows during the transition process were also revealed from the analysis of the instantaneous velocity fields. The results can be a measure of identifying the critical Reynolds number of the Taylor-Couette flow from a velocity measurement method.

Clinical utility of the Taylor spatial frame for limb deformities

Directory of Open Access Journals (Sweden)

Keshet D

2017-05-01

Full Text Available Doron Keshet, Mark Eidelman Pediatric Orthopedics Unit, Rambam Health Care Center, Haifa, Israel Abstract: The Taylor spatial frame (TSF is a hexapod external fixator that can correct six-axis deformities. The mathematical base of all hexapod systems is projective geometry, which describes complex repositioning of an object in space. The Taylor brothers developed one of the first six-axis correction systems, which is known today as TSF. Over the years, this system has become the most used six-axis deformity correction device. In this review, we describe the history behind TSF development, and describe the principles and clinical utility for application of the TSF in different settings, such as acute trauma, malunions, and various deformities of the lower and upper limb. Keywords: external fixator, deformity correction, hexapod

Learner Perceptions of the Introduction of Computer-Assisted Learning in Mathematics at a Peri-Urban School in South Africa

Science.gov (United States)

Hartley, M. Shaheed; Treagust, David F.

2014-01-01

This study responded to a national call to improve the outcomes in mathematics in the Grade 12 matriculation examination in South Africa by reporting learners' perceptions of the introduction of computer-assisted learning in their mathematics classrooms. Three Grade 12 mathematics classes in a peri-urban school in South Africa were visited over a…

Investigation of the Taylor vortices in electrovortex flow

Science.gov (United States)

Vinogradov, D. A.; Ivochkin, Yu P.; Teplyakov, I. O.

2017-10-01

The structure of the electrovortex flow appearing when the electric current passing through the liquid metal interacts with own and external magnetic fields was investigated numerically. It was shown that axial external magnetic field leads to the rotation of the liquid and generates secondary flow similar to Taylor vortex. Calculations were carried out for various ratios of electrode sizes.

Influence of a magnetic field on the Taylor instability in magnetic fluids

International Nuclear Information System (INIS)

Vislovich, A.N.

1986-01-01

The influence of a magnetic field on the stability of Couette flow between rotating cylinders is investigated in the narrow gap approximation. The governing mechanism of the instability is the classical Taylor mechanism. It was shown that rotation of the outer cylinder in the same direction as the inner does not result in a qualitative change in the structure of the theshold perturbations. When the cylinders rotate in different directions in an ordinary fluid, the Taylor vortices develop in the domain of the gap between the inner cylinder and the fluid layer for which v 0 = 0

LASNEX simulations of the classical and laser-driven Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Mikaelian, K.O.

1990-01-01

We present the results of two-dimensional LASNEX simulations of the classical and laser-driven Rayleigh-Taylor instability. Our growth rates and eigenmodes for classical two- and three-fluid problems agree closely with the exact analytic expressions. We illustrate in several examples how perturbations feed through from one interface to another. For targets driven by a 1/4-μm laser at I=2x10 14 W/cm 2 our growth rates are 40--80 % of the classical case rates for wavelengths between 5 and 100 μm. We find that radiation transport has a stabilizing effect on the Rayleigh-Taylor instability, particularly at high intensities. A brief comparison with a laser-driven experiment is also presented

Proactive educational reforms in South Korea: Schools for Improvement and multicultural education

OpenAIRE

Lee, Hye-Won

2014-01-01

Introduction This paper discusses the educational issues and societal changes that have led to proactive reforms in the education system of South Korea. Korean pupils achieve high academic levels, but there have been some criticisms relating to sociocultural issues. In addition, Korea is being transformed into a multicultural society. Here we consider two examples of Korea’s educational interventions, introduced in response to contextual demands and societal changes: firstly, the Schools for...

Theoretical and numerical study of Rayleigh-Taylor instabilities in magnetized plasmas; Etude theorique et numerique des instabilites rayleigh-taylor en plasmas magnetises

Energy Technology Data Exchange (ETDEWEB)

Andrei, A. Ivanov

2001-06-15

In this thesis we're studying both the general case of the 'classic' Rayleigh-Taylor instability (in incompressible fluids) and more specific cases of the instabilities of Rayleigh-Taylor type in magnetized plasmas, in the liners or wire array implosions etc. We have studied the influence of the Hall diffusion of magnetic field on the growth rate of the instability. We have obtained in this work a self-similar solution for the widening of the initial profile of the magnetic field and for the wave of the penetration of magnetic field. After that the subsequent evolution of the magnetic field in plasma opening switches (POS) has been examined. We have shown the possibility of the existence of a strong rarefaction wave for collisional and non-collisional cases. This wave can explain the phenomenon of the opening of POS. The effect of the suppression of Rayleigh-Taylor instability by forced oscillations of the boundary between two fluids permits us to propose some ideas for the experiments of inertial fusion. We have considered the general case of the instability, in other words - two incompressible viscous superposed fluids in a gravitational field. We have obtained an exact analytical expression for the growth rate and then we have analyzed the influence of the parameters of external 'pumping' on the instability. These results can be applied to a wide range of systems, starting from classic hydrodynamics and up to astrophysical plasmas. The scheme of wire arrays has become recently a very popular method to obtain a high power X-radiation or for a high quality implosion in Z-pinches. The experimental studies have demonstrated that the results of implosion are much better for the case of multiple thin wires situated cylindrically than in a usual liner scheme. We have examined the problem modeling the stabilization of Rayleigh-Taylor instability for a wire array system. The reason for instability suppression is the regular spatial modulation of

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.

2015-02-23

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.; McCue, Scott W.; Dallaston, Michael C.; Moroney, Timothy J.

2015-01-01

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Monetary Policy and the Taylor Principle in Open Economies

NARCIS (Netherlands)

Linnemann, L.; Schabert, A.

2006-01-01

Nowadays, central banks mostly conduct monetary policy by setting nominal interest rates. A widely held view is that central banks can stabilize inflation if they follow the Taylor principle, which requires raising the nominal interest rate more than one-for-one in response to higher inflation. Is

Coherent structures in ablatively compressed ICF targets and Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Pant, H.C.; Desai, T.

1996-01-01

One of the major issues in laser induced inertial confinement fusion (ICF) is a stable ablative compression of spherical fusion pellets. The main impediment in achievement of this objective is Rayleigh-Taylor instability at the pellet's ablation front. Under sufficiently high acceleration this instability can grow out of noise. However, it can also arise either due to non-uniform laser intensity distribution over the pellet surface or due to pellet wall areal mass irregularity. Coherent structures in the dense target behind the ablation front can be effectively utilised for stabilisation of the Rayleigh-Taylor phenomenon. Such coherent structures in the form of a super lattice can be created by doping the pellet pusher with high atomic number (Z) micro particles. A compressed-cool pusher under laser irradiation behaves like a strongly correlated non ideal plasma when compressed to sufficiently high density such that the non ideality parameter exceeds unity. Moreover, the nonideality parameter for high Z microinclusions may exceed a critical value of 180 and as a consequence they remain in the form of intact clusters, maintaining the superlattice intact during ablative acceleration. Micro-hetrogeneity and its superlattice plays an important role in stabilization of Rayleigh-Taylor instability, through a variety of mechanisms. (orig.)

"Smuggling the Vernacular into the Classroom": Conflicts and Tensions in Classroom Codeswitching in Township/Rural Schools in South Africa

Science.gov (United States)

Probyn, Margie

2009-01-01

In South Africa, as in many parts of postcolonial Africa, English dominates the political economy and as a result is the medium of instruction chosen by the majority of South African schools, despite the fact that most learners do not have the opportunity to acquire English to the levels necessary for effective engagement with the curriculum.…

Relationship between school dropout and teen pregnancy among rural South African young women.

Science.gov (United States)

Rosenberg, Molly; Pettifor, Audrey; Miller, William C; Thirumurthy, Harsha; Emch, Michael; Afolabi, Sulaimon A; Kahn, Kathleen; Collinson, Mark; Tollman, Stephen

2015-06-01

Sexual activity may be less likely to occur during periods of school enrolment because of the structured and supervised environment provided, the education obtained and the safer peer networks encountered while enrolled. We examined whether school enrolment was associated with teen pregnancy in South Africa. Using longitudinal demographic surveillance data from the rural Agincourt sub-district, we reconstructed the school enrolment status from 2000 through 2011 for 15 457 young women aged 12-18 years and linked them to the estimated conception date for each pregnancy during this time. We examined the effect of time-varying school enrolment on teen pregnancy using a Cox proportional hazard model, adjusting for: age; calendar year; household socioeconomic status; household size; and gender, educational attainment and employment of household head. A secondary analysis compared the incidence of pregnancy among school enrolees by calendar time: school term vs school holiday. School enrolment was associated with lower teen pregnancy rates [adjusted hazard ratio (95% confidence interval): 0.57 (0.50, 0.65)].This association was robust to potential misclassification of school enrolment. For those enrolled in school, pregnancy occurred less commonly during school term than during school holidays [incidence rate ratio (95% confidence interval): 0.90 (0.78, 1.04)]. Young women who drop out of school may be at higher risk for teen pregnancy and could likely benefit from receipt of accessible and high quality sexual health services. Preventive interventions designed to keep young women in school or addressing the underlying causes of dropout may also help reduce the incidence of teen pregnancy. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Stochastic model of Rayleigh-Taylor turbulent mixing

International Nuclear Information System (INIS)

Abarzhi, S.I.; Cadjan, M.; Fedotov, S.

2007-01-01

We propose a stochastic model to describe the random character of the dissipation process in Rayleigh-Taylor turbulent mixing. The parameter alpha, used conventionally to characterize the mixing growth-rate, is not a universal constant and is very sensitive to the statistical properties of the dissipation. The ratio between the rates of momentum loss and momentum gain is the statistic invariant and a robust parameter to diagnose with or without turbulent diffusion accounted for

A taylor series approach to survival analysis

International Nuclear Information System (INIS)

Brodsky, J.B.; Groer, P.G.

1984-09-01

A method of survival analysis using hazard functions is developed. The method uses the well known mathematical theory for Taylor Series. Hypothesis tests of the adequacy of many statistical models, including proportional hazards and linear and/or quadratic dose responses, are obtained. A partial analysis of leukemia mortality in the Life Span Study cohort is used as an example. Furthermore, a relatively robust estimation procedure for the proportional hazards model is proposed. (author)

Taylor Law in Wind Energy Data

Directory of Open Access Journals (Sweden)

Rudy Calif

2015-10-01

Full Text Available The Taylor power law (or temporal fluctuation scaling, is a scaling relationship of the form σ ~  (Pλ where !! is the standard deviation and hPi the mean value of a sample of a time series has been observed for power output data sampled at 5 min and 1 s and from five wind farms and a single wind turbine, located at different places. Furthermore, an analogy with the turbulence field is performed, consequently allowing the establishment of a scaling relationship between the turbulent production IP and the mean value (P.

Education within public management in South Africa: A focus on external Whole-School Evaluation process’ contribution in Mpumalanga province

Directory of Open Access Journals (Sweden)

Richard Siphamandla Ryan Mathaba

2015-08-01

Full Text Available The study focused on the role played by public sector management in South Africa towards the country’s total development and improvement. This article also analyses how through the Whole School Evaluation (WSE process, the education system in South Africa seeks to ensure that the schooling is effective. This paper examines public management, public administration as well as new public management (NPM. The aim is to illustrate a view of how education fits in the broader public management and how the WSE process assists schooling in South Africa and Mpumalanga in particular. This is to ensure that the schooling is effective and contribute towards service delivery and the country’s overall development and improvement. Furthermore, WSE as a process, is viewed through five of NPM undisputable and debatable characteristics of accountability for performance; performance measurement; performance auditing; policy analysis and evaluation; and strategic planning and management. Public management functions and public management principles are discussed from a point of how the WSE process strives to ensure that it complies with these function and principles, and how this compliance benefit school improvement. This paper came to a number of conclusions regarding education within public management from a WSE perspective. Firstly, education through the external WSE process conforms to this principle of New Public Management in that evaluation is aimed at improving the quality of education. Also, the external WSE, as a process, and education in general, through the NPM principles can be performed within public management. Furthermore, external WSE conforms to public management principles as well as Batho Pele principles.

Validity of the Taylor hypothesis for linear kinetic waves in the weakly collisional solar wind

International Nuclear Information System (INIS)

Howes, G. G.; Klein, K. G.; TenBarge, J. M.

2014-01-01

The interpretation of single-point spacecraft measurements of solar wind turbulence is complicated by the fact that the measurements are made in a frame of reference in relative motion with respect to the turbulent plasma. The Taylor hypothesis—that temporal fluctuations measured by a stationary probe in a rapidly flowing fluid are dominated by the advection of spatial structures in the fluid rest frame—is often assumed to simplify the analysis. But measurements of turbulence in upcoming missions, such as Solar Probe Plus, threaten to violate the Taylor hypothesis, either due to slow flow of the plasma with respect to the spacecraft or to the dispersive nature of the plasma fluctuations at small scales. Assuming that the frequency of the turbulent fluctuations is characterized by the frequency of the linear waves supported by the plasma, we evaluate the validity of the Taylor hypothesis for the linear kinetic wave modes in the weakly collisional solar wind. The analysis predicts that a dissipation range of solar wind turbulence supported by whistler waves is likely to violate the Taylor hypothesis, while one supported by kinetic Alfvén waves is not.

The Decline and Revival of Music Education in New South Wales Schools, 1920-1956

Science.gov (United States)

Chaseling, Marilyn; Boyd, William E.

2014-01-01

This paper overviews the decline and revival of music education in New South Wales schools from 1920 to 1956. Commencing with a focus on vocal music during the period up to 1932, a time of decline in music teaching, the paper examines initiatives introduced in 1933 to address shortcomings in music education, and the subsequent changes in…

A Conceptual Exploration of Values Education in the Context of Schooling in South Africa

Science.gov (United States)

Solomons, Inez; Fataar, Aslam

2011-01-01

This article is based on the assumption that values education has much to offer to a country that is struggling to overcome a fractured moral landscape. Pursuing a modest agenda, the focus of the article is on values and values education in the context of schooling in South Africa. We suggest that debates about what constitutes values and values…

Learner Pregnancy--Perceptions on Its Prevalence and the Child Support Grant (CSG) Being the Possible Cause in South African Secondary Schools

Science.gov (United States)

Naong, Matsidiso Nehemia

2011-01-01

Learner pregnancy has recently become a thorn in the flesh for most schools in South Africa, and documentary evidence shows that its prevalence is greater amongst Black public schools than White schools. Within its discourse, more often than not, the Child Support Grant (CSG) has featured prominently in the perceived increase in the pregnancy rate…

Traveling waves in a magnetized Taylor-Couette flow

International Nuclear Information System (INIS)

Liu Wei; Ji Hantao; Goodman, Jeremy

2007-01-01

We investigate numerically a traveling wave pattern observed in experimental magnetized Taylor-Couette flow at low magnetic Reynolds number. By accurately modeling viscous and magnetic boundaries in all directions, we reproduce the experimentally measured wave patterns and their amplitudes. Contrary to previous claims, the waves are shown to be transiently amplified disturbances launched by viscous boundary layers, rather than globally unstable magnetorotational modes

The Role of Social Capital at Home and in School in Academic Achievement: The Case of South Korea

Science.gov (United States)

Yang, Hyunwoo

2017-01-01

Using data from the Korean Educational Longitudinal Study of 2005-2007, the current study investigated the role of family and school social capital in students' academic achievement in South Korea. Results showed that while some forms of family and school social capital were associated with increased math achievement, the effect of family social…

One Leader, One School and an Atypical South African Educational Landscape: The Pedagogical Viability of a Shared Technology Project

Science.gov (United States)

van Jaarsveld, Leentjie; Mentz, P. J.; van der Walt, Johannes L.

2016-01-01

Visionary leaders shape their actions and initiate transformation to reach a specific goal. To do so is critically important in South Africa, where the education system offers limited opportunities to manage a school in a manner that deviates from the prescribed norm. School leaders typically encounter barriers such as the inadequacy of the…

Theoretical and numerical studies of Rayleigh-Taylor instabilities in magnetized plasmas

International Nuclear Information System (INIS)

Ivanov, A.A.

2001-06-01

The instabilities of Rayleigh-Taylor type are considered in the thesis. The topic of the thesis was inspired by recent advances in the physics of plasma compression, especially with the aid of systems like Z-pinch. Rayleigh-Taylor instability (RTI) plays an important role in the evolution of magnetized plasmas in these experiments, as well as in stellar plasmas and classic fluids. For the phenomena concerning the nuclear fusion the RTI is very often the factor limiting the possibility of compression. In the current work we try to examine in detail the characteristic features of the instabilities of this type in order to eliminate their detrimental influence. In this thesis we are studying both the general case of the 'classic' Rayleigh-Taylor instability (in incompressible fluids) and more specific cases of the instabilities of Rayleigh-Taylor type in magnetized plasmas, in the liners or wire array implosions etc. We have studied the influence of the Hall diffusion of magnetic field on the growth rate of the instability. We have obtained in this work a self-similar solution for the widening of the initial profile of the magnetic field and for the wave of the penetration of magnetic field. After that the subsequent evolution of the magnetic field in plasma opening switches (POS) has been examined. We have shown the possibility of the existence of a strong rarefaction wave for collisional and non-collisional cases. This wave can explain the phenomenon of the opening of POS. The effect of the suppression of Rayleigh-Taylor instability by forced oscillations of the boundary between two fluids permits us to propose some ideas for the experiments of inertial fusion. We have considered the general case of the instability, in other words, two incompressible viscous superposed fluids in a gravitational field. We have obtained an exact analytical expression for the growth rate and then we have analyzed the influence of the parameters of external 'pumping' on the instability

Skills training through hands-on practical activities in civil technology – a case study of three technical schools in South Africa

Directory of Open Access Journals (Sweden)

Mogale Maeko

2014-12-01

Full Text Available Skills training for Civil Technology learners in South African schools, is an aspect entrenched in the Civil Technology policy document in order to produce skilled personnel for a sustainable economy. Practical activities through the Practical Assessment Task (PAT are national requirements for all practical-based subjects from grades 10–12 in South African schools. The purpose of this study was to investigate the status of Civil Technology practical activities in three South African schools in the Eastern Cape Province. Purposive sampling was used to identify 41 learners and 3 teachers to participate in the study. Questionnaires, semi-structured interviews and observation as data collection methods were instruments used to collect data. The study has found that learners exit grade 12 without basic practical hands-on skills. Civil Technology practical activities were found to be inadequately offered in the three schools investigated. Educators should be well-trained by higher education institutions (HEIs to conduct practical activities with learners so that these learners are equipped with marketable skills in order to contribute to a sustainable economy after grade 12. Technology teacher education and training should include regular exposure and visits to relevant industries in order for teachers to keep abreast with the latest technological developments. The supply of equipment to schools should be coupled with routine maintenance of the equipment.

Ten-year secular trend of overweight and obesity in school children in south-eastern Poland

Directory of Open Access Journals (Sweden)

Artur Mazur

2014-09-01

Full Text Available Objective. To examine the trend in prevalence of overweight and obesity in schoolchildren from south-eastern Poland over a 10-year period. Materials and Method. A cross-sectional study was conducted in randomly selected primary schools. In total, 4,248 children (2,182 boys and 2,066 girls, mean age 10.5±2.4 years, were examined in 1998, and 2,412 children (1,184 boys and 1,228 girls, mean age 10.5±2.3 years in 2008. In each school the entire population was studied. Results. In 2008, the prevalence of overweight in girls was 13.3% and obesity 7.7%, compared to 12.0% and 10.1% in 1998. The decrease in obesity prevalence was statistically significant. In boys, the prevalence of overweight in 2008 was 14.2% and obesity 6.4%, compared to 10.5% and 6.8% in 1998. The increase in overweight prevalence among boys was statistically significant. Conclusions. A trend toward stabilization of the prevalence of overweight and obesity was noted in school children from south-eastern Poland between 1998–2008. The declining prevalence of obesity in girls and increased prevalence of overweight in boys demonstrates that in this age group of children the secular trend is gender dependent.

Development of Rayleigh-Taylor and bulk convection instabilities in the dynamics of plasma liners and pinches

International Nuclear Information System (INIS)

Bud'ko, A.B.; Velikovich, A.L.; Liberman, M.A.; Felber, F.S.

1989-01-01

A solution is derived for the problem of the initial, linear stage of the growth of small perturbations in the course of the cylindrically symmetric compression and expansion of a plasma liner and a Z-pinch with a sharp boundary. In these systems, Rayleigh-Taylor instabilities localized near the plasma boundaries are the most dangerous. Bulk convective instabilities develop in addition to these Rayleigh-Taylor instabilities. The various instability modes, including local and global Rayleigh-Taylor modes, which grown in an accelerated plasma with distributed profiles of hydrodynamic variables, are classified. The spectra of the instability growth rates are calculated for plasma liners and Z-pinches. The shape of these spectra reveals an explanation of the stratification and filamentation of the plasma observed experimentally in pinches and liners. The imposition of a longitudinal magnetic field gives rise to a stability window in the space of the flow parameters. In this window, the Rayleigh-Taylor modes are suppressed completely by magnetic shear, while the bulk convective modes are suppressed to a significant extent

Effect of magnetic field on Rayleigh-Taylor instability of quantum and stratified plasma in porous medium

International Nuclear Information System (INIS)

Sharma, P.K.; Tiwari, Anita; Argal, Shraddha; Chhajlani, R.K.

2013-01-01

This paper is devoted to an investigation of Quantum effects and magnetic field effects on the Rayleigh Taylor instability of two superposed incompressible fluids in bounded porous medium. The Quantum magneto hydrodynamic equations are solved by using normal mode method and a dispersion relation is obtained. The dispersion relation is derived for the case where plasma is bounded by two rigid planes z = 0 and z = h. The Rayleigh Taylor instability growth rate and stability condition of the medium is discussed in the presence of quantum effect, magnetic field, porosity and permeability. It is found that the magnetic field and medium porosity have stabilizing influence while permeability has destabilizing influence on the Rayleigh Taylor instability. (author)

The man with the dirty black beard: race, class, and schools in the antebellum South.

Science.gov (United States)

Watson, Harry L

2012-01-01

The problem of poor, degraded white people in the antebellum South presented a problem to both reformers and proponents of slavery. Sharpening the differences of race meant easing those of class, ensuring that public schooling did not always receive widespread support. The cult of white superiority absolved the state of responsibility for social mobility. As better schooling was advocated for religious and civic reasons, wealthy planters determined to avoid taxes joined with their illiterate neighbors in fighting attempts at “improvement” that undermined the slave system based on the notion of black inferiority.

Creating Supportive Learning Environments: Experiences of Lesbian and Gay-Parented Families in South African Schools

Science.gov (United States)

Breshears, Diana; Lubbe-De Beer, Carien

2016-01-01

Through in-depth interviews with 21 parents and 12 children in lesbian/gay-parented families, we explored the experiences of this unique family form in South African schools. Specifically, families reflected on their positive and negative experiences in the children's education and used these reflections to offer advice to teachers and…

Paper-Based GIS: A Practical Answer to the Implementation of GIS Education into Resource-Poor Schools in South Africa

Science.gov (United States)

Breetzke, Gregory; Eksteen, Sanet; Pretorius, Erika

2011-01-01

Geographical information systems (GIS) were phased into the geography curriculum of South African schools from 2006-2008 as part of the National Curriculum Statement (NCS) for grades 10-12. Since its introduction, GIS education in schools across the country has been met with a number of challenges including the cost of purchasing the hardware and…

From Taylor to Drucker: Management and Managing

OpenAIRE

Primoz Turk

2008-01-01

The article discusses the question of management and managing, focusing on the changes which took place in the period from Taylor to Drucker. In this period two turning points dramatically changed the nature of management. Management which started within the organization was at first concerned with the organization’s inner workings. This concern with the organization’s ‘inside’ is gradually projected to the outside, to society as a whole. Simultaneously, changes occur in managing. Managing wh...

Liquidity Trap and Stability of Taylor Rules

OpenAIRE

Le Riche , Antoine; Magris , Francesco; Parent , Antoine

2016-01-01

We study a productive economy with fractional cash-in-advance constraint on consumption expenditures. Government issues safe bonds and levies taxes to finance public expenditures, while the Central Bank follows a feedback Taylor rules by pegging the nominal interest rate. We show that when the nominal interest rate is bound to be non-negative, under active policy rules a Liquidity Trap steady state does emerge besides the Leeper (1991) equilibrium. The stability of the two steady states depen...

"Six Packs and Big Muscles, and Stuff like That". Primary School-Aged South African Boys, Black and White, on Sport

Science.gov (United States)

Bhana, Deevia

2008-01-01

This paper explores the salience of sport in the lives of eight-year-old and nine-year-old South African primary school boys. Drawing on ethnographic and interview data, I argue that young boys' developing relationship with sport is inscribed within particular gendered, raced and classed discourses in South Africa. Throughout the paper I show…

The One Laptop School: Equipping Rural Elementary Schools in South India Through Public Private Partnerships

Directory of Open Access Journals (Sweden)

Erik Jon Byker

2015-11-01

Full Text Available This article reports on a Public Private Partnership (PPP program in South India that provided information and communication technology (ICT to rural elementary schools. The article examined the current status of rural, government-run elementary schools in India by reviewing reports like the Annual Status of Education Report (ASER in India. Challenges like teacher absences, student drop-outs, lack of electricity, lack of separate toilets for genders, and a lack of teaching resources is discussed. To meet these challenges, the article describes the rise in popularity of India’s PPPs. Then the article reports on a case study of a PPP, called the SSA Foundation, which implemented a “one laptop per school” program in rural areas in the Indian States of Karnataka and Tamil Nadu. Using ethnographic data from field research, the case study includes a description of how the students in a rural Karnataka elementary school use their school’s laptop. The school was situated in a small village where most travel was non-motorized. Walking, usually without shoes, was the main form of transportation. A bicycle was considered a luxury. Most villagers worked in the surrounding ragi and millet fields; laboring, often with only simple tool blades. Wood fires were the main source of fuel for cooking. In this village, the school’s laptop became a prized possession. The case study offers a “thick description” (Geertz, 1973 of how the village school’s students used the laptop for learning basic computing skills and for learning English.

Direct numerical simulations of type Ia supernovae flames II: The Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

2004-01-01

A Type Ia supernova explosion likely begins as a nuclear runaway near the center of a carbon-oxygen white dwarf. The outward propagating flame is unstable to the Landau-Darrieus, Rayleigh-Taylor, and Kelvin-Helmholtz instabilities, which serve to accelerate it to a large fraction of the speed of sound. We investigate the Rayleigh-Taylor unstable flame at the transition from the flamelet regime to the distributed-burning regime, around densities of 10e7 gm/cc, through detailed, fully resolved simulations. A low Mach number, adaptive mesh hydrodynamics code is used to achieve the necessary resolution and long time scales. As the density is varied, we see a fundamental change in the character of the burning--at the low end of the density range the Rayleigh-Taylor instability dominates the burning, whereas at the high end the burning suppresses the instability. In all cases, significant acceleration of the flame is observed, limited only by the size of the domain we are able to study. We discuss the implications of these results on the potential for a deflagration to detonation transition

Measurement of the Rayleigh-Taylor instability in targets driven by optically smoothed laser beams

International Nuclear Information System (INIS)

Desselberger, M.; Willi, O.; Savage, M.; Lamb, M.J.

1990-01-01

Growth rates of the Rayleigh-Taylor instability were measured in targets with imposed sinusoidal modulations irradiated by optically smoothed 0.53-μm laser beams. A hybrid optical smoothing technique utilizing induced-spatial-incoherence and random-phase-plate technology was used for the first time. The wave-number dependence and the nonlinear behavior of Rayleigh-Taylor growth were investigated by using targets with a range of modulation periodicities and depths. The results are compared to 2D hydrodynamic-code simulations

The carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica

International Nuclear Information System (INIS)

Lyons, W.B.; Leslie, D.L.; Harmon, R.S.; Neumann, K.; Welch, K.A.; Bisson, K.M.; McKnight, D.M.

2013-01-01

Highlights: ► δ 13 C-DIC reported from McMurdo Dry Valleys, Antarctica, streams. ► Stream water δ 13 C PDB values range −9.4‰ to +5.1‰, largely inorganic in character. ► Atmospheric exchange is the dominant control on δ 13 C-DIC. - Abstract: The McMurdo Dry Valleys region of Antarctica is the largest ice-free region on the continent. This study reports the first C stable isotope measurements for dissolved inorganic C present in ephemeral streams in four dry valleys that flow for four to twelve weeks during the austral summer. One of these valleys, Taylor Valley, has been the focus of the McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) program since 1993. Within Taylor Valley, numerous ephemeral streams deliver water to three perennially ice-covered, closed-basin lakes: Lake Fryxell, Lake Hoare, and Lake Bonney. The Onyx River in the Wright Valley, the longest river in Antarctica, flows for 40 km from the Wright Lower Glacier and Lake Brownworth at the foot of the glacier to Lake Vanda. Streamflow in the McMurdo Dry Valley streams is produced primarily from glacial melt, as there is no overland flow. However, hyporheic zone exchange can be a major hydrogeochemical process in these streams. Depending on landscape position, these streams vary in gradient, channel substrate, biomass abundance, and hyporheic zone extent. This study sampled streams from Taylor, Wright, Garwood, and Miers Valleys and conducted diurnal sampling of two streams of different character in Taylor Valley. In addition, transect sampling was undertaken of the Onyx River in Wright Valley. The δ 13 C PDB values from these streams span a range of greater than 14‰, from −9.4‰ to +5.1‰, with the majority of samples falling between −3‰ and +2‰, suggesting that the C stable isotope composition of dissolved C in McMurdo Dry Valley streams is largely inorganic in character. Because there are no vascular plants on this landscape and no groundwater input to these

Parametric modulation in the Taylor-Couette ferrofluid flow

International Nuclear Information System (INIS)

Singh, Jitender; Bajaj, Renu

2008-01-01

A parametric instability of the Taylor-Couette ferrofluid flow excited by a periodically oscillating magnetic field, has been investigated numerically. The Floquet analysis has been employed. It has been found that the modulation of the applied magnetic field affects the stability of the basic flow. The instability response has been found to be synchronous with respect to the frequency of periodically oscillating magnetic field.

Rayleigh-Taylor instability in an equal mass plasma

Energy Technology Data Exchange (ETDEWEB)

Adak, Ashish, E-mail: ashish-adak@yahoo.com [Department of Instrumentation Science, Jadavpur University, Kolkata 700 032 (India); Ghosh, Samiran, E-mail: sran-g@yahoo.com [Department of Applied Mathematics, University of Calcutta 92, Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Chakrabarti, Nikhil, E-mail: nikhil.chakrabarti@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

2014-09-15

The Rayleigh-Taylor (RT) instability in an inhomogeneous pair-ion plasma has been analyzed. Considering two fluid model for two species of ions (positive and negative), we obtain the possibility of the existence of RT instability. The growth rate of the RT instability as usual depends on gravity and density gradient scale length. The results are discussed in context of pair-ion plasma experiments.

Awareness in Primary School Teachers regarding Traumatic Dental Injuries in Children and Their Emergency Management: A Survey in South Jaipur.

Science.gov (United States)

Nirwan, Mitakshara; Syed, Ather Ahmed; Chaturvedi, Shefali; Goenka, Puneet; Sharma, Swati

2016-01-01

Trauma to primary and permanent teeth and their supporting structures is one of the most common dental problems seen in children. The prognosis of traumatized teeth depends on timely attention with prompt and appropriate treatment, which often relies on knowledge of the teachers who may be present at the place of accidents. Thus, the aim of this study was to evaluate via a questionnaire the knowledge level of primary school teachers in South Jaipur regarding dental trauma. Questionnaire survey. A self-designed questionnaire was administered to 300 primary school teachers from 20 randomly selected private and semi-aided schools of South Jaipur. A total of 278 teachers responded to the survey. The collected data were subjected to statistical analysis. It was found that most of the respondents had accepted poor knowledge regarding dental trauma, with a mean knowledge of 10.56 ± 2.58. This study highlighted inadequate knowledge regarding emergency management of traumatic dental injuries, and teachers felt the need for training in the management of dental trauma as part of their training program. How to cite this article: Nirwan M, Syed AA, Chaturvedi S, Goenka P, Sharma S. Awareness in Primary School Teachers regarding Traumatic Dental Injuries in Children and Their Emergency Management: A Survey in South Jaipur. Int J Clin Pediatr Dent 2016;9(1):62-66.

Reflections on Teaching Periodic Table Concepts: A Case Study of Selected Schools in South Africa

Science.gov (United States)

Mokiwa, Hamza Omari

2017-01-01

The Periodic Table of Elements is central to the study of modern Physics and Chemistry. It is however, considered by teachers as difficult to teach. This paper reports on a case study exploring reflections on teaching periodic table concepts in five secondary schools from South Africa. Qualitative methodology of interviews and document analysis…

Cyberbullying in South African and American schools: A legal comparative study

Directory of Open Access Journals (Sweden)

DM Smit

2015-05-01

Full Text Available Bullying conjures up visions of the traditional schoolyard bully and the subordinate victim. However, bullying is no longer limited to in-person encounter, having come to include cyberbullying, which takes place indirectly over electronic media. In this electronic age, cyber platforms proliferate at an astonishing rate, all attracting the youth in large number, and posing the risk that they may become subject to cyberbullying. Far from being limited to those individual learners being cyberbullied, the effects of this phenomenon extend to the learner collective, the school climate, and also the entire school system, management and education, thus requiring an urgent response. This article first provides a general overview of cyberbullying and its impact on learners, schools and education. This is done through a comparative lens, studying the extent of the phenomenon in both the United States and South Africa. The focus then shifts to the existing legislative frameworks within which the phenomenon is tackled in these respective jurisdictions, particularly the tricky balancing act required between learners' constitutional right to free speech and expression, and the protection of vulnerable learners' right to equality, dignity and privacy. The article concludes by proposing certain possible solutions to the problem.

Educating Adolescents in the Context of Section 504 Policy: a Comparative Study of Two Middle Schools

OpenAIRE

Taylor, Martha Asterilla

2002-01-01

EDUCATING ADOLESCENTS IN THE CONTEXT OF SECTION 504 POLICY: A COMPARATIVE STUDY OF TWO MIDDLE SCHOOLS By Martha Asterilla Taylor Jean B. Crockett, Ph.D. Chairperson Educational Leadership and Policy Studies (ABSTRACT) Section 504 "prohibits discrimination against persons with disabilities by school districts receiving federal financial assistance" (First & Curcio, 1993, p.33). In public schools, eligible students receive an Individualized Accommodation Plan (IA...

Learners' perspectives on the provision of condoms in South African public schools.

Science.gov (United States)

de Bruin, W E; Panday-Soobrayan, S

2017-12-01

A stubborn health challenge for learners in South African public schools concerns sexual and reproductive health and rights (SRHR). In 2015, the Department of Basic Education (DBE) proposed the provision of condoms and SRHR-services to learners in schools. This study aimed to contribute to the finalisation and implementation of DBE's policy by exploring learners' perspectives on the provision of condoms and SRHR-services in schools. Sixteen focus group discussions were conducted with learners (n = 116) from 33 public schools, to assess their attitudes, social influences, and needs and desires regarding condom provision and SRHR-services in schools. The majority of learners did not support condom provision in schools as they feared that it may increase sexual activity. Contrarily, they supported the provision of other SRHR-services as clinics fail to offer youth-friendly services. Learners' sexual behaviour and access to SRHR-services are strongly determined by their social environment, including traditional norms and values, and social-pressure from peers and adults. Learners' most pressing needs and desires to access condoms and SRHR-services in school concerned respect, privacy and confidentiality of such service provision. Implementation of DBE's policy must be preceded by an evidence-informed advocacy campaign to debunk myths about the risk of increased sexual activity, to advocate for why such services are needed, to shift societal norms towards open discussion of adolescent SRHR and to grapple with the juxtaposition of being legally empowered but socially inhibited to protect oneself from HIV, STIs and early pregnancy. Provision of condoms and other SRHR-services in schools must be sensitive to learners' privacy and confidentiality to minimise stigma and discrimination.

Taylor-expansion Monte Carlo simulations of classical fluids in the canonical and grand canonical ensemble

International Nuclear Information System (INIS)

Schoen, M.

1995-01-01

In this article the Taylor-expansion method is introduced by which Monte Carlo (MC) simulations in the canonical ensemble can be speeded up significantly, Substantial gains in computational speed of 20-40% over conventional implementations of the MC technique are obtained over a wide range of densities in homogeneous bulk phases. The basic philosophy behind the Taylor-expansion method is a division of the neighborhood of each atom (or molecule) into three different spatial zones. Interactions between atoms belonging to each zone are treated at different levels of computational sophistication. For example, only interactions between atoms belonging to the primary zone immediately surrounding an atom are treated explicitly before and after displacement. The change in the configurational energy contribution from secondary-zone interactions is obtained from the first-order term of a Taylor expansion of the configurational energy in terms of the displacement vector d. Interactions with atoms in the tertiary zone adjacent to the secondary zone are neglected throughout. The Taylor-expansion method is not restricted to the canonical ensemble but may be employed to enhance computational efficiency of MC simulations in other ensembles as well. This is demonstrated for grand canonical ensemble MC simulations of an inhomogeneous fluid which can be performed essentially on a modern personal computer

Ensuring an optimal environment for peer education in South African schools: Goals, systems, standards and policy options for effective learning.

Science.gov (United States)

Swartz, Sharlene; Deutsch, Charles; Moolman, Benita; Arogundade, Emma; Isaacs, Dane; Michel, Barbara

2016-12-01

Peer education has long been seen as a key health promotion strategy and an important tool in preventing HIV infection. In South African schools, it is currently one of the strategies employed to do so. Based on both a recent research study of peer education across 35 schools and drawing on multiple previous studies in South Africa, this paper examines the key elements of peer education that contribute to its effectiveness and asks how this aligns with current educational and health policies. From this research, it summarises and proposes shared goals and aims, minimum standards of implementation and reflects on the necessary infrastructure required for peer education to be effective. In light of these findings, it offers policy recommendations regarding who should be doing peer education and the status peer education should have in a school's formal programme.

The relationship between BMI and dietary intake of primary school children from a rural area of South Africa: The Ellisras longitudinal study

NARCIS (Netherlands)

Van Den Ende, C.; Twisk, J.W.R.; Monyeki, K.D.

2014-01-01

Objectives: To investigate the relationship between dietary intake and BMI of primary school children from a rural area of South Africa cross-sectionally. Both under and over nutrition remain major health problems in South Africa. In rural areas, where especially undernutrition leads to child

Principals' Self-Perceived Transformational Leadership Behaviors and Academic Achievement in South Carolina Public Elementary Schools

Science.gov (United States)

Newman, Je-Nata Kennedy

2017-01-01

The purpose of this quantitative correlational study was to examine the relationship between principals' perceptions of their transformational leadership behaviors and academic achievement in the areas of reading, math, science, and social studies in South Carolina public elementary schools. The theoretical framework for this research was provided…

Inward propagating chemical waves in Taylor vortices.

Science.gov (United States)

Thompson, Barnaby W; Novak, Jan; Wilson, Mark C T; Britton, Melanie M; Taylor, Annette F

2010-04-01

Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses--also observed experimentally.

Taylor Principle Supplements the Fisher Effect: Empirical Investigation under the US Context

Directory of Open Access Journals (Sweden)

Mohammed Saiful ISLAM

2012-06-01

Full Text Available This paper reviews the short- and long-run dynamics of interest rate and inflation of the United States. Basing upon quarterly as well as monthly data over the period 1957 to 2010, we find evidence that interest rate behaviour of the Federal Reserve is consistent with the Taylor principle in short run and with the Fisher hypothesis in long run. Entire sample justifies the existence of a long run cointegrating relationship between federal funds rate and inflation characterised as the Fisher effect. When data are split into different subsamples, the cointegrating relationship disappears. Interest rate dynamics of pre-1980 and post-2001 neither track Fisher hypothesis nor Taylor principle, rather represent substantial discretion.

Learners’ constructions of bullying in a South African school context

Directory of Open Access Journals (Sweden)

Zibeleni L. Hlophe

2017-07-01

Full Text Available Drawing on social constructionism as a theoretical paradigm, this article foregrounds learners’ voices to depict the profiles of bullies and bullying victims within a cultural context of one coeducational secondary school in Hammarsdale in South Africa. The article uses qualitative data from semi-structured individual and focus group interviews as well as a participatory mapping exercise based on a narrative study of six purposefully sampled Grade 9 learners, aged between 13 and 16 years. The findings denote learners’ social identities such as gender, sexual orientation, economic status, age, stature and complexion as critical determinants in the incitement and formation of bully–victim relations. The complex forms, causes and spaces of bullying are highlighted to denote its pervasiveness and the extent of the school’s illpreparedness to effectively respond to bullying incidents. The study recommends education policy and practice reformists foreground learners’ understanding and experiences of bullying as a basis for enhancing social inclusiveness, tolerance and safe schooling environments, for enhanced equitable quality of learning experiences for all the learners.

FACTORS CONTRIBUTING TO SUBSTANCE (DRUG ABUSE AMONGMALE ADOLESCENTS IN SOUTH AFRICAN PUBLIC SECONDARY SCHOOLS

Directory of Open Access Journals (Sweden)

Irene Mohasoa

2017-01-01

Full Text Available This small-scale study sought to determine the factors that contribute to use ofdrugs by male adolescents in South African public secondary schools. The studywas conducted in four secondary schools in Zeerust, North West, a province ofSouth Africa. Purposive sampling was employed to select from the secondaryschools 12 male adolescents who were prone to substance abuse problems. Aqualitative research approach was followed underpinned by the interpretiveresearch paradigm. More specifically, a multiple case research design was used.The study was successful in identifying the most commonly used drugs such asalcohol, nicotine, cannabis, and heroin. These drugs are readily available in thesurrounding communities and are affordable to the learners. Socialand economicfactors are the main factors contributing to the use of drugs among maleadolescents. The way in which children are brought up, who they associate withand whether they have access to money to buy the drugs largely contribute to druguse. Thisstudy concludes by proposing mitigation strategies that can be employedto deal with substance abuse scourge before it escalates further. Furthermore, thestudy identifies a need for involvement of various stakeholders to find a solutionto the substanceabuse problem.

How is their word knowledge growing? Exploring Grade 3 vocabulary in South African township schools

Directory of Open Access Journals (Sweden)

Elizabeth J. Pretorius

2017-11-01

Full Text Available In this article, we report on a study that examined the active and receptive English vocabulary of two different groups of Grade 3 learners in South African township schools. The groups consisted of English Home Language (HL learners in the Western Cape and Xhosa HL and English First Additional Language (FAL learners in the Eastern Cape. The purpose was to document their different vocabulary trajectories during Grade 3. The Woodcock-Muñoz Language Survey was used to measure the active vocabulary levels of 118 learners at the beginning and the end of the school year. Another 284 learners from the same eight Grade 3 classes participated in a receptive vocabulary test at the end of the year. This test assessed their knowledge of the 60 most frequent words that occur in South Africa Grade 4 English textbooks. Results showed that although the HL learners knew almost double the number of words their English FAL peers did, both groups of learners increased their active word knowledge through the year by about 9%. Regarding their receptive vocabulary, the English FAL learners on average only knew 27% of the most frequent words at the end of their Grade 3. No significant gender differences were found. Learners in both language groups who were above their grade age had significantly lower scores than their younger peers. This confirms findings that children who start school with weak language skills tend to stay weak. Finally, initial active vocabulary knowledge was found to be a strong predictor of vocabulary development during the school year.

CREATING SUPPORTIVE LEARNING ENVIRONMENTS: EXPERIENCES OF LESBIAN AND GAY-PARENTED FAMILIES IN SOUTH AFRICAN SCHOOLS

Directory of Open Access Journals (Sweden)

Diana Breshears

2016-06-01

Full Text Available Through in-depth interviews with 21 parents and 12 children in lesbian/gayparented families, we explored the experiences of this unique family form in South African schools. Specifically, families reflected on their positive and negative experiences in the children’s education and used these reflections to offer advice to teachers and administrators wishing better to support lesbian/ gay-parented families. The results of our study offer an understanding of the challenges and needs of this diverse family in the school system, as well as a starting point for administrators and teachers wanting to create inclusive environments for all family types.

Identità e riconoscimento in Charles Taylor

Directory of Open Access Journals (Sweden)

Francesca Caputo

2013-06-01

Full Text Available The model of the politic of difference, proposed by Charles Taylor, in the wake of a conception of liberalism ‘hospitable’, unfolds in a journey aimed to comply with the ontological dimensions of the dignity of different cultures, of cultural traditions and ways of life. Being a self, constructed in terms of dialogue and dialectic of mutual recognition between cultures, refers, in the Charles Taylor’s reflection, to the safeguarding of single, intersubjective or common meanings of specific social, moral, narrative spaces.

Hydromagnetic Rayleigh-Taylor instability in cylindrical implosions

International Nuclear Information System (INIS)

Hwang, C.S.; Roderick, N.F.; Wu, M.W.

1986-01-01

Rayleigh-Taylor Instability in the (r,Θ) plane has been solved by the variational approach. Results are compared to the analytical solutions of two-region and three-region problems at the infinite radius. They show the magnetic stabilization effect. Growth rates in this plane are decreased by the effects of plasma shell thickness, plasma shell radius, magnetic tension, magnetic diffusion and finite density gradient of the plasma magnetic field interface. The most unstable mode number decreases when the radius of the plasma shell decreases

The solution of the point kinetics equations via converged accelerated Taylor series (CATS)

Energy Technology Data Exchange (ETDEWEB)

Ganapol, B.; Picca, P. [Dept. of Aerospace and Mechanical Engineering, Univ. of Arizona (United States); Previti, A.; Mostacci, D. [Laboratorio di Montecuccolino, Alma Mater Studiorum - Universita di Bologna (Italy)

2012-07-01

This paper deals with finding accurate solutions of the point kinetics equations including non-linear feedback, in a fast, efficient and straightforward way. A truncated Taylor series is coupled to continuous analytical continuation to provide the recurrence relations to solve the ordinary differential equations of point kinetics. Non-linear (Wynn-epsilon) and linear (Romberg) convergence accelerations are employed to provide highly accurate results for the evaluation of Taylor series expansions and extrapolated values of neutron and precursor densities at desired edits. The proposed Converged Accelerated Taylor Series, or CATS, algorithm automatically performs successive mesh refinements until the desired accuracy is obtained, making use of the intermediate results for converged initial values at each interval. Numerical performance is evaluated using case studies available from the literature. Nearly perfect agreement is found with the literature results generally considered most accurate. Benchmark quality results are reported for several cases of interest including step, ramp, zigzag and sinusoidal prescribed insertions and insertions with adiabatic Doppler feedback. A larger than usual (9) number of digits is included to encourage honest benchmarking. The benchmark is then applied to the enhanced piecewise constant algorithm (EPCA) currently being developed by the second author. (authors)

Pinch instabilities in Taylor-Couette flow.

Science.gov (United States)

Shalybkov, Dima

2006-01-01

The linear stability of the dissipative Taylor-Couette flow with an azimuthal magnetic field is considered. Unlike ideal flows, the magnetic field is a fixed function of a radius with two parameters only: a ratio of inner to outer cylinder radii, eta, and a ratio of the magnetic field values on outer and inner cylinders, muB. The magnetic field with 0rotation. The unstable modes are located into some interval of the axial wave numbers for the flow stable without magnetic field. The interval length is zero for a critical Hartmann number and increases with an increasing Hartmann number. The critical Hartmann numbers and length of the unstable axial wave number intervals are the same for every rotation law. There are the critical Hartmann numbers for m=0 sausage and m=1 kink modes only. The sausage mode is the most unstable mode close to Ha=0 point and the kink mode is the most unstable mode close to the critical Hartmann number. The transition from the sausage instability to the kink instability depends on the Prandtl number Pm and this happens close to one-half of the critical Hartmann number for Pm=1 and close to the critical Hartmann number for Pm=10(-5). The critical Hartmann numbers are smaller for kink modes. The flow stability does not depend on magnetic Prandtl numbers for m=0 mode. The same is true for critical Hartmann numbers for both m=0 and m=1 modes. The typical value of the magnetic field destabilizing the liquid metal Taylor-Couette flow is approximately 10(2) G.

High School Learners' Mental Construction during Solving Optimisation Problems in Calculus: A South African Case Study

Science.gov (United States)

Brijlall, Deonarain; Ndlovu, Zanele

2013-01-01

This qualitative case study in a rural school in Umgungundlovu District in KwaZulu-Natal, South Africa, explored Grade 12 learners' mental constructions of mathematical knowledge during engagement with optimisation problems. Ten Grade 12 learners who do pure Mathemat-ics participated, and data were collected through structured activity sheets and…

Life stages of wall-bounded decay of Taylor-Couette turbulence

NARCIS (Netherlands)

Ostilla-Mónico, Rodolfo; Zhu, Xiaojue; Arza, Vamsi Spandan; Verzicco, Roberto; Lohse, Detlef

2017-01-01

The decay of Taylor-Couette turbulence, i.e., the flow between two coaxial and independently rotating cylinders, is numerically studied by instantaneously stopping the forcing from an initially statistically stationary flow field at a Reynolds number of Re=3.5×104. The effect of wall friction is

Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

Science.gov (United States)

Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

2011-01-01

Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

Horizontally viscous effects in a tidal basin: extending Taylor's problem

NARCIS (Netherlands)

Roos, Pieter C.; Schuttelaars, H.M.

2009-01-01

The classical problem of Taylor (Proc. Lond. Math. Soc., vol. 20, 1921, pp. 148–181) of Kelvin wave reflection in a semi-enclosed rectangular basin of uniform depth is extended to account for horizontally viscous effects. To this end, we add horizontally viscous terms to the hydrodynamic model

Gender Gap in Maths Test Scores in South Korea and Hong Kong: Role of Family Background and Single-Sex Schooling

Science.gov (United States)

Kim, Doo Hwan; Law, Helen

2012-01-01

In many industrialised societies, women remain underrepresented in the sciences, which can be predicted by the gender gap in math achievement at school. Using PISA 2006 data, we explore the role of family background and single-sex schooling in girls' disadvantage in maths in South Korea and Hong Kong. This disadvantage is found to be associated…

The Contribution of the New South Wales Primary Schools Sports Association towards Developing Talent in Australian 12-Year-Old Female Swimmers

Science.gov (United States)

Light, Richard

2012-01-01

This article reports on a case study that inquired into the influence of the New South Wales Primary Schools Sports Association competitive swimming structure on the development of talented 12-year old female swimmers. The study focused on ten 12-year old girls in the New South Wales team that contested the 2009 national swimming championships…

The verification of the Taylor-expansion moment method in solving aerosol breakage

Directory of Open Access Journals (Sweden)

Yu Ming-Zhou

2012-01-01

Full Text Available The combination of the method of moment, characterizing the particle population balance, and the computational fluid dynamics has been an emerging research issue in the studies on the aerosol science and on the multiphase flow science. The difficulty of solving the moment equation arises mainly from the closure of some fractal moment variables which appears in the transform from the non-linear integral-differential population balance equation to the moment equations. Within the Taylor-expansion moment method, the breakage-dominated Taylor-expansion moment equation is first derived here when the symmetric fragmentation mechanism is involved. Due to the high efficiency and the high precision, this proposed moment model is expected to become an important tool for solving population balance equations.

Primary schoolchildren’s self-reported sun-related knowledge, attitudes and behaviours: a South African school-based study

CSIR Research Space (South Africa)

Wright, C

2013-09-01

Full Text Available The objective of this paper is to describe the self-reported sun-related knowledge, attitudes and behaviours of a sample of South African multi-ethnic primary schoolchildren and consider the roles of sex and skin type as well as school sun...

Rayleigh-Taylor instability of a self-similar spherical expansion

International Nuclear Information System (INIS)

Bernstein, I.B.; Book, D.L.

1978-01-01

The self-similar motion of a spherically symmetric isentropic cloud of ideal gas driven outward by an expanding low-density medium (e.g., radiation pressure from a pulsar) is shown to be unstable to Rayleigh-Taylor modes which develop in the neighborhood of the interface. A complete solution of the linearized equations of motion is obtained. The implications for astrophysical phenomena are discussed

A STUDY ON MENSTRUAL HEALTH IN SCHOOL GOING ADOLESCENT GIRLS FROM SOUTH INDIA

Directory of Open Access Journals (Sweden)

Vinitra Dayalan

2017-09-01

Full Text Available BACKGROUND The major Problems occurring during the adolescent period is related to menstrual cycle. Data regarding the burden of menstrual disturbances in school going children of South India is lacking. Assessing the burden in such children may aid in revealing the current state of menstrual health and hence aiding the policy makes to take appropriate measures. Hence, we assessed the prevalence of menstrual disturbances in school going adolescent girls of South India. The primary aim of this study is to assess the burden of menstrual disorders in school going adolescent girls. The secondary objective were to assess individual menstrual disturbance in the study group and to assess the various factors influencing the menstrual health. MATERIALS AND METHODS This cross-sectional study was conducted in two government girl’s higher secondary school in the state of Tamil Nadu, India. After receiving approval, a structured questionnaire in the regional language (Tamil was distributed to the school going children between the age of 10 and 19 years. Demographic data and details regarding menstrual health were collected. Frequency of medical assistance and school absenteeism were also analysed in patients with dysmenorrhea. Data were analysed using the SPSS 13.0.1. RESULTS Data of 340 girls who have attained menarche and who have completed the questionnaire was analysed. The median age of menarche in the study group was 13 years. (IQR; 12, 14 and 13.2% attained early menarche(before12 years. There was a higher prevalence of menstrual disturbances; (46.2% with polymenorrhea and (12% with oligomenorrhea. there was a significantly higher usage of sanitary pads in our study population in our study group (98%. In addition, (41.5% had premenstrual symptoms and (36.8% had dysmenorrhea. With a higher prevalence of dysmenorrhea (n=125, 35 had school absenteeism. But, only 8/35 consulted a physician and took treatment. Five of these patients were told to have

On stabilization of the Rayleigh-Taylor instability for the imploding liner on account of ion-ion collisions

International Nuclear Information System (INIS)

Gordeev, Alexander V.

2002-01-01

The stabilization of the Rayleigh-Taylor instability for the imploding cylindrical liner in the limit of a low plasma density Π ω pi 2 δ2/c2 << 1 (δ -- the characteristic size of the current layer) is investigated, when the electron currents are much greater than the ion currents. The stabilization of the Rayleigh-Taylor instability for the parameter diapason νii/ωBi < (Z2M/m)1/2 is considered, when the plasma dissipation connected with the ion-ion collisions considerably superior the usual dissipation due to the electron-ion collisions. For the electric conductivity, caused by the ion-ion collisions and resulted in the minimum value σ ∼ enc/B, the effect of the partial stabilization of the Rayleigh-Taylor instability is demonstrated

On the CFD Analysis of a Stratified Taylor-Couette System Dedicated to the Fabrication of Nanosensors

Directory of Open Access Journals (Sweden)

Duccio Griffini

2017-02-01

Full Text Available Since the pioneering work of Taylor, the analysis of flow regimes of incompressible, viscous fluids contained in circular Couette systems with independently rotating cylinders have charmed many researchers. The characteristics of such kind of flows have been considered for some industrial applications. Recently, Taylor-Couette flows found an innovative application in the production of optical fiber nanotips, to be used in molecular biology and medical diagnostic fields. Starting from the activity of Barucci et al., the present work concerns the numerical analysis of a Taylor-Couette system composed by two coaxial counter-rotating cylinders with low aspect ratio and radius ratio, filled with three stratified fluids. An accurate analysis of the flow regimes is performed, considering both the variation of inner and outer rotational speed and the reduction of fiber radius due to etching process. The large variety of individuated flow configurations provides useful information about the possible use of the Taylor-Couette system in a wide range of engineering applications. For the present case, the final objective is to provide accurate information to manufacturers of fiber nanotips about the expected flow regimes, thus helping them in the setup of the control process that will be used to generate high-quality products.

Taylor-Couette fluid flow with force oscillation in the inner-cylinder using the immersed boundary method

Energy Technology Data Exchange (ETDEWEB)

Borges, Jonatas Emmanuel; Lourenco, Marcos Antonio de Souza; Padilla, Elie Luis Martinez; Silveira Neto, Aristeu da [Federal University of Uberlandia , MG (Brazil)], e-mails: lourenco@mecanica.ufu.br, epadilla@mecanica.ufu.br, aristeus@mecanica.ufu.br; Leibsohn, Andre Martins [CENPES/Petrobras, Rio de Janeiro, RJ (Brazil)], e-mail: aleibsohn@petrobras.com

2010-07-01

As new challenges arise in the exploration of deep and ultra-deep water oil fields by PETROBRAS more knowledge and research are needed, so that tools could be developed to assist in the critical operations and make things practicable. In the context of the drilling process, the complexity of the fluid flow inside the riser is associated with the nature of the non-Newtonian flow, immersed solid particles, variable eccentricity and the superimposed traveling azimuthal waves on the inflow and outflow boundaries of the Taylor vortices. This work presents the numerical three-dimensional results of the following simplified fluid flows: Taylor-Couette, Taylor-Couette with varying imposed eccentricity and Taylor-Couette with forced oscillation in the inner cylinder. Using the Navier-Stokes equations, a finite volume method discretization with second order accuracy in both time and space was utilized to simulate the Newtonian, single-phase incompressible fluid flow in the three cases. The circular walls of the inner and outer cylinders are represented by the immersed boundary method, with the direct multi-forcing model. The determined results allow to evidence the flow structures in the three cases in a very qualitative way, even so in the presence of the inner cylinder oscillation. (author)

RADIATIVE RAYLEIGH-TAYLOR INSTABILITIES

International Nuclear Information System (INIS)

Jacquet, Emmanuel; Krumholz, Mark R.

2011-01-01

We perform analytic linear stability analyses of an interface separating two stratified media threaded by a radiation flux, a configuration relevant in several astrophysical contexts. We develop a general framework for analyzing such systems and obtain exact stability conditions in several limiting cases. In the optically thin, isothermal regime, where the discontinuity is chemical in nature (e.g., at the boundary of a radiation pressure-driven H II region), radiation acts as part of an effective gravitational field, and instability arises if the effective gravity per unit volume toward the interface overcomes that away from it. In the optically thick a diabaticregime where the total (gas plus radiation) specific entropy of a Lagrangian fluid element is conserved, for example at the edge of radiation pressure-driven bubble around a young massive star, we show that radiation acts like a modified equation of state and derive a generalized version of the classical Rayleigh-Taylor stability condition.

Indoor and outdoor PM10 levels at schools located near mine dumps in Gauteng and North West Provinces, South Africa

Directory of Open Access Journals (Sweden)

Vusumuzi Nkosi

2017-01-01

Full Text Available Abstract Background Few studies in South Africa have investigated the exposure of asthmatic learners to indoor and outdoor air pollution at schools. This study compared outdoor PM10 and SO2 exposure levels in exposed (1–2 km from gold mine dumps and unexposed schools (5 km or more from gold mine dumps. It also examined exposure of asthmatic children to indoor respirable dust at exposed and unexposed schools. Methods The study was conducted between 1 and 31 October 2012 in five schools from exposed and five from unexposed communities. Outdoor PM10 and SO2 levels were measured for 8-h at each school. Ten asthmatic learners were randomly selected from each school for 8-h personal respirable dust sampling during school hours. Results The level of outdoor PM10 for exposed was 16.42 vs. 11.47 mg.m−3 for the unexposed communities (p < 0.001. The outdoor SO2 for exposed was 0.02 ppb vs. 0.01 ppb for unexposed communities (p < 0.001. Indoor respirable dust in the classroom differed significantly between exposed (0.17 mg.m−3 vs. unexposed (0.01 mg.m−3 children with asthma at each school (p < 0.001. Conclusion The significant differences between exposed and unexposed schools could reveal a serious potential health hazard for school children, although they were within the South African Air Quality Standards’ set by the Department of Environmental Affairs. The indoor respirable dust levels in exposed schools could have an impact on children with asthma, as they were significantly higher than the unexposed schools, although there are no published standards for environmental exposure for children with asthma.

The Changing Nature of the Role of Principals in Primary and Junior Secondary Schools in South Australia Following the Introduction Local School Management (Partnerships 21)

Science.gov (United States)

Sahid, Abdul

2004-01-01

This paper discusses the changing nature of the role of principals following the introduction of local school management (Partnerships 21) in South Australia. The study reports the series of interviews with primary and junior secondary principals with regard to their roles in several areas namely; instructional leadership, teachers' professional…

Taylorism given a helping hand

DEFF Research Database (Denmark)

Tolsby, June

2000-01-01

of the IT system was perceived by some of the employees. Shows how, instead of increasing employees' work engagement, the IT system had the opposite effect. Demonstrates that the new It system contributed to a deskilling of the employees, to a more task-oriented approach to their work, and to increased employees......Illustrates how th implementation of a major information technology (IT) system within the Norwegian Army affected the way the employees perceived their flexibility and personal involvement in their work. By employing Taylor's initial works, this paper illustrates how the introduction......' interdependence. Instead of increasing employees' personal flexibility and involvement in their jobs, the research shows how the new IT system in fact contributed to a reduction in the freedom to choose when and how quickly to do their jobs....

Suppression of the Rayleigh-Taylor instability due to self-radiation in a multiablation target

International Nuclear Information System (INIS)

Fujioka, Shinsuke; Sunahara, Atsushi; Nishihara, Katsunobu; Johzaki, Tomoyuki; Shiraga, Hiroyuki; Shigemori, Keisuke; Nakai, Mitsuo; Ikegawa, Tadashi; Murakami, Masakatsu; Nagai, Keiji; Norimatsu, Takayoshi; Azechi, Hiroshi; Yamanaka, Tatsuhiko; Ohnishi, Naofumi

2004-01-01

A scheme to suppress the Rayleigh-Taylor instability has been investigated for a direct-drive inertial fusion target. In a high-Z doped-plastic target, two ablation surfaces are formed separately--one driven by thermal radiation and the other driven by electron conduction. The growth of the Rayleigh-Taylor instability is significantly suppressed on the radiation-driven ablation surface inside the target due to the large ablation velocity and long density scale length. A significant reduction of the growth rate was observed in simulations and experiments using a brominated plastic target. A new direct-drive pellet was designed using this scheme

Local Nusselt number enhancement during gas-liquid Taylor bubble flow in a square mini-channel: An experimental study

International Nuclear Information System (INIS)

Majumder, Abhik; Mehta, Balkrishna; Khandekar, Sameer

2013-01-01

Taylor bubble flow takes place when two immiscible fluids (liquid-liquid or gas-liquid) flow inside a tube of capillary dimensions within specific range of volume flow ratios. In the slug flows where gas and liquid are two different phases, liquid slugs are separated by elongated Taylor bubbles. This singular flow pattern is observed in many engineering mini-/micro-scale devices like pulsating heat pipes, gas-liquid-solid monolithic reactors, micro-two-phase heat exchangers, digital micro-fluidics, micro-scale mass transfer process, fuel cells, etc. The unique and complex flow characteristics require understanding on local, as well as global, spatio-temporal scales. In the present work, the axial stream-wise profile of the fluid and wall temperature for air-water (i) isolated single Taylor bubble and, (ii) a train of Taylor bubbles, in a horizontal square channel of size 3.3 mm x 3.3 mm x 350 mm, heated from the bottom (heated length = 175 mm), with the other three sides kept insulated, are reported at different gas volume flow ratios. The primary aim is to study the enhancement of heat transfer due to the Taylor bubble train flow, in comparison with thermally developing single-phase flows. Intrusion of a bubble in the liquid flow drastically changes the local temperature profiles. The axial distribution of time-averaged local Nusselt number (Nu z ) shows that Taylor bubble train regime increases the transport of heat up to 1.2-1.6 times more as compared with laminar single-phase liquid flow. In addition, for a given liquid flow Reynolds number, the heat transfer enhancement is a function of the geometrical parameters of the unit cell, i.e., the length of adjacent gas bubble and water plug. (authors)

Probabilistic assessment of the rainwater harvesting potential of schools in South Africa

Directory of Open Access Journals (Sweden)

J. G. Ndiritu

2014-09-01

Full Text Available In comparison to other sources of water supply, rainwater harvesting (RWH has the typical advantages of being cheaper and easier to operate and maintain. This study aimed at assessing the hydrologic rainwater harvesting potential of rural schools in South Africa by obtaining RWH storage capacity (level of supply reliability relationships of representative schools. Thirty-two schools located in three rural areas that have varied rainfall characteristics were selected for the analysis. For each school, a daily time-step behaviour analysis of the rainwater harvesting system with a specified storage was carried out for a period of 101 years (over which rainfall data was available and the number of days that the school’s daily water demand was met in each year obtained. Using the Weibull plotting position formula, the expected number of days that the demand can be met per year was then obtained for 85, 90 and 95 % reliability. For the two summer rainfall regions where a large proportion of rain falls during school holidays, the expected number of days of supply per year improved up to a storage capacity of 25 m3. For the winter rainfall region where the rainfall periods and school learning times have more co-incidence, a tank volume of 5 m3 obtained similar supply levels as larger capacities. At 90 % reliability, the supply levels for different schools in the summer rainfall area with a mean annual precipitation (MAP of 800–1000 mm/year ranged from 60 to 120 days per year, while the summer rainfall region with a lower MAP (500–600 mm gave supply levels ranging from 40 to 70 days per year. The winter rainfall area had a MAP of 500–600 mm and obtained supply levels ranging from 60 to 80 days at 90 % reliability.

Rayleigh-Taylor instability in a visco-plastic fluid

International Nuclear Information System (INIS)

Demianov, A Yu; Doludenko, A N; Son, E E; Inogamov, N A

2010-01-01

The Rayleigh-Taylor and Richtmyer-Meshkov instabilities of a visco-plastic fluid are discussed. The Bingham model is used as an effective rheological model which takes into account plastic effects. For the purposes of numerical simulation a one-mode disturbance of the contact surface between two fluids is considered. The main goal of this work is to construct numerical 2D and 3D models and to obtain the relationship between yield stress and the development of instability.

Rayleigh-Taylor instability in a visco-plastic fluid

Science.gov (United States)

Demianov, A. Yu; Doludenko, A. N.; Inogamov, N. A.; Son, E. E.

2010-12-01

The Rayleigh-Taylor and Richtmyer-Meshkov instabilities of a visco-plastic fluid are discussed. The Bingham model is used as an effective rheological model which takes into account plastic effects. For the purposes of numerical simulation a one-mode disturbance of the contact surface between two fluids is considered. The main goal of this work is to construct numerical 2D and 3D models and to obtain the relationship between yield stress and the development of instability.

Mixing and axial dispersion in Taylor-Couette flow: experimental and numerical study

International Nuclear Information System (INIS)

Nemri, M.

2013-01-01

Taylor-Couette flows between two concentric cylinders have great potential applications in chemical engineering. They are particularly convenient for two-phase small scale devices enabling solvent extraction operations. An experimental device was designed with this idea in mind. It consists of two concentric cylinders with the inner one rotating and the outer one fixed. Taylor-Couette flows take place in the annular gap between them, and are known to evolve towards turbulence through a sequence of successive instabilities. Macroscopic quantities, such as axial dispersion and mixing index, are extremely sensitive to these flow structures, which may lead to flawed modelling of the coupling between hydrodynamics and mass transfer. This particular point has been studied both experimentally and numerically. The flow and mixing have been characterized by means of flow visualization and simultaneous PIV (Particle Imaging Velocimetry) and PLIF (Planar Laser Induced Fluorescence) measurements. PLIF visualizations showed clear evidences of different transport mechanisms including 'intra-vortex mixing' and 'inter-vortex mixing'. Under WVF and MWVF regimes, intra-vortex mixing is controlled by chaotic advection, due to the 3D nature of the flow, while inter-vortex transport occurs due to the presence of waves between neighboring vortices. The combination of these two mechanisms results in enhanced axial dispersion. We showed that hysteresis may occur between consecutive regimes depending on flow history and this may have a significant effect on mixing for a given Reynolds number. The axial dispersion coefficient Dx evolution along the successive flow states was investigated thanks to dye Residence Time Distribution measurements (RTD) and particle tracking (DNS). Both experimental and numerical results have confirmed the significant effect of the flow structure and history on axial dispersion. Our study confirmed that the commonly used 1-parameter chemical engineering models (e

Adult-onset epilepsy in focal cortical dysplasia of Taylor type

NARCIS (Netherlands)

Siegel, A. M.; Cascino, G. D.; Elger, C. E.; Devinsky, O.; Laff, R.; Najjar, S.; Sperling, M. R.; LoRusso, G.; Cossu, M.; Urbach, H.; Aronica, E.; Meyer, F. B.; Scheithauer, B. W.; Dubeau, F.; Andermann, F.

2005-01-01

Focal cortical dysplasia of Taylor type (FCDT) usually presents with seizures at an early age, whereas adult onset of epilepsy is uncommon. We reviewed the medical records of 213 patients with FCDT. In 21 patients (10%), age at seizure onset ranged from 18 to 55 years (mean 25.3). The outcome of

Rayleigh-Taylor and wind-driven instabilities of the nighttime equatorial ionosphere

International Nuclear Information System (INIS)

Chiu, Y.T.; Straus, J.M.

1979-01-01

We have made a thorough re-examination of the Rayleigh-Taylor instability in the nighttime equatorial ionosphere from approx.100 km to the bottomside F region. We have taken into account explicitly the following effects which have been ignored by other workers in various combinations: (1) The eastward drift of the ionosphere caused by the nighttime polarization electric field, (2) the eastward nighttime neutral wind, and (3) recombination in the F and E regions. We found that, well below the bottomside F region, the Rayleigh-Taylor mode can be unstable and is driven by an eastward neutral wind rather than by gravitational drift. Formation of ionospheric bubbles below the bottomside F region is consistent with the observation of lower ionospheric ions in F region ionospheric holes; furthermore, seasonal and shorter term variations in spread-F occurrence may be associated with variations in the neutral wind and polarization electric field

Participative leadership practice in junior high schools and actions to improve the practice : a case study of Sekyere south district, Ghana

OpenAIRE

Gyasi, Kwame

2015-01-01

Gyasi, Kwame. 2015. Participative leadership practice in junior high schools and actions to improve the practice: a case study of Sekyere south district, Ghana Master's Thesis in Education. University of Jyväskylä. Department of Education Participative leadership practice is seen as the kind of school leadership which recognizes parents’ contribution and teachers’ ability and talents in leadership by sharing with them roles and responsibilities in the school administrative process. Th...

The Impact of Computer and Mathematics Software Usage on Performance of School Leavers in the Western Cape Province of South Africa: A Comparative Analysis

Science.gov (United States)

Smith, Garth Spencer; Hardman, Joanne

2014-01-01

In this study the impact of computer immersion on performance of school leavers Senior Certificate mathematics scores was investigated across 31 schools in the EMDC East education district of Cape Town, South Africa by comparing performance between two groups: a control and an experimental group. The experimental group (14 high schools) had access…

Identification of Dynamic Loads Based on Second-Order Taylor-Series Expansion Method

Directory of Open Access Journals (Sweden)

Xiaowang Li

2016-01-01

Full Text Available A new method based on the second-order Taylor-series expansion is presented to identify the structural dynamic loads in the time domain. This algorithm expresses the response vectors as Taylor-series approximation and then a series of formulas are deduced. As a result, an explicit discrete equation which associates system response, system characteristic, and input excitation together is set up. In a multi-input-multi-output (MIMO numerical simulation study, sinusoidal excitation and white noise excitation are applied on a cantilever beam, respectively, to illustrate the effectiveness of this algorithm. One also makes a comparison between the new method and conventional state space method. The results show that the proposed method can obtain a more accurate identified force time history whether the responses are polluted by noise or not.

Effect of resistivity on the Rayleigh-Taylor instability in an accelerated plasma

International Nuclear Information System (INIS)

Castillo, J.L.; Huerta, M.A.

1993-01-01

We study the Rayleigh-Taylor instability in finite-conductivity accelerated plasma arcs of the type found in electromagnetic rail launchers. For a plasma of length l, acceleration a, and thermal speed v T we consider the case where v T 2 /al much-gt 1, which is valid when the projectile mass is large compared to the plasma mass. The conductivity σ enters via a magnetic Reynolds number R=σμ(al 3 ) 1/2 . The fourth-order mode equation is solved analytically using an asymptotic WKB expansion in 1/R. We find the first-order 1/R correction to the classical Rayleigh-Taylor dispersion relation for large wave number K but with K much-lt R 2 /l. The analytical results show good agreement with previous numerical calculations

James Taylor (1859-1946): favourite disciple of Hughlings Jackson and William Gowers.

Science.gov (United States)