title: Steady free surface flows induced by a submerged ring source or sink

authors: Stokes, Tim E.

subjects: critical layers

abstract: The steady axisymmetric flow induced by a ring sink (or source) submerged in an unbounded inviscid fluid is computed and the resulting deformation of the free surface is obtained. Solutions are obtained analytically in the limit of small Froude number (and hence small surface deformation) and numerically for the full nonlinear problem. The small Froude number solutions are found to have the property that if the non-dimensional radius of the ring sink is less than ρ=√2, there is a central stagnation point on the surface surrounded by a dip which rises to the stagnation level in the far distance. However, as the radius of the ring sink increases beyond ρ=√2, a surface stagnation ring forms and moves outward as the ring sink radius increases. It is also shown that as the radius of the sink increases, the solutions in the vicinity of the ring sink/source change continuously from those due to a point sink/source (ρ=0) to those due to a line sink/source (ρ→∞). These properties are confirmed by the numerical solutions to the full nonlinear equations for finite Froude numbers. At small values of the Froude number and sink or source radius, the nonlinear solutions look like the approximate solutions, but as the flow rate increases a limiting maximum Froude number solution with a secondary stagnation ring is obtained. At large values of sink or source radius, however, this ring does not form and there is no obvious physical reason for the limit on solutions. The maximum Froude numbers at which steady solutions exist for each radius are computed.

text: Steady free surface flows induced by a submerged ring source or sink The steady axisymmetric flow induced by a ring sink (or source) submerged in an unbounded inviscid fluid is computed and the resulting deformation of the free surface is obtained. Solutions are obtained analytically in the limit of small Froude number (and hence small surface deformation) and numerically for the full nonlinear problem. The small Froude number solutions are found to have the property that if the non-dimensional radius of the ring sink is less than ρ=√2, there is a central stagnation point on the surface surrounded by a dip which rises to the stagnation level in the far distance. However, as the radius of the ring sink increases beyond ρ=√2, a surface stagnation ring forms and moves outward as the ring sink radius increases. It is also shown that as the radius of the sink increases, the solutions in the vicinity of the ring sink/source change continuously from those due to a point sink/source (ρ=0) to those due to a line sink/source (ρ→∞). These properties are confirmed by the numerical solutions to the full nonlinear equations for finite Froude numbers. At small values of the Froude number and sink or source radius, the nonlinear solutions look like the approximate solutions, but as the flow rate increases a limiting maximum Froude number solution with a secondary stagnation ring is obtained. At large values of sink or source radius, however, this ring does not form and there is no obvious physical reason for the limit on solutions. The maximum Froude numbers at which steady solutions exist for each radius are computed.

year: 2012

title: A bi-objective model for supply chain design of dispersed manufacturing in China

authors: Zhang, Abraham

subjects: supply chain management

abstract: Dispersed manufacturing achieves the greatest cumulative competitive advantage by dissecting a supply chain and assigning each process to an optimal location. Dispersed manufacturing has been an integral part of global manufacturing in China. This paper presents a bi-objective model for the supply chain design of dispersed manufacturing in the context of rising business operating costs in coastal China. It considers essential trade-offs between supply chain cost and lead time to determine optimal facility locations of manufacturing steps. The model is applied to a representative case to illustrate the cost benefits of dispersed manufacturing as opposed to performing all manufacturing steps of a product at a single facility location. It provides explanations in several factors that have benefited manufacturing growth in China, and offers insights in the emerging global manufacturing trends.

text: A bi-objective model for supply chain design of dispersed manufacturing in China Dispersed manufacturing achieves the greatest cumulative competitive advantage by dissecting a supply chain and assigning each process to an optimal location. Dispersed manufacturing has been an integral part of global manufacturing in China. This paper presents a bi-objective model for the supply chain design of dispersed manufacturing in the context of rising business operating costs in coastal China. It considers essential trade-offs between supply chain cost and lead time to determine optimal facility locations of manufacturing steps. The model is applied to a representative case to illustrate the cost benefits of dispersed manufacturing as opposed to performing all manufacturing steps of a product at a single facility location. It provides explanations in several factors that have benefited manufacturing growth in China, and offers insights in the emerging global manufacturing trends.

year: 2013

title: E Toru Ngā Reo: A Case Study of a Spanish Language Programme in a Kura Kaupapa Māori

authors: Flavell, William

subjects: Kaupapa Maori Research

abstract: Learning Languages is a new area in the 2007 New Zealand Curriculum.  However there have not been many studies in this subject.  Kura Kaupapa Māori, established in 1985 in New Zealand with over 6,000 students currently attending, have English language programmes (Hill, 2010), however few, if any, studies of the teaching of other languages have been conducted.  The purpose of this study was to describe and evaluate an additional international language programme at a Kura Kaupapa Māori.

This qualitative case study describes the views of the Principal, five teachers, five students and three parents of a Kura Kaupapa Māori about an additional Spanish language programme. The primary means of gathering data was through individual semi-structured interviews.  Interviews were used to collect data in the areas of identifying the attitudes of the participants towards learning an additional international language, the perceived benefits, if any, of learning an additional international language and if there is a relationship between the learning of an  additional international language, and Kaupapa Māori.  The narrative data was transcribed, coded and categorised into four themes related to the research questions.  

 The success of this Spanish language programme can be understood in terms of several factors such as whānau support, programme leadership, quality teachers, international excursions and positive attitudes to foreign language learning.  

These findings will contribute to literature concerning additional language learning programmes, specifically those based in indigenous language immersion settings and they will also provide useful information and ideas which other Kura Kaupapa Māori can take advantage of when implementing additional international language learning programmes.

text: E Toru Ngā Reo: A Case Study of a Spanish Language Programme in a Kura Kaupapa Māori Learning Languages is a new area in the 2007 New Zealand Curriculum.  However there have not been many studies in this subject.  Kura Kaupapa Māori, established in 1985 in New Zealand with over 6,000 students currently attending, have English language programmes (Hill, 2010), however few, if any, studies of the teaching of other languages have been conducted.  The purpose of this study was to describe and evaluate an additional international language programme at a Kura Kaupapa Māori.

This qualitative case study describes the views of the Principal, five teachers, five students and three parents of a Kura Kaupapa Māori about an additional Spanish language programme. The primary means of gathering data was through individual semi-structured interviews.  Interviews were used to collect data in the areas of identifying the attitudes of the participants towards learning an additional international language, the perceived benefits, if any, of learning an additional international language and if there is a relationship between the learning of an  additional international language, and Kaupapa Māori.  The narrative data was transcribed, coded and categorised into four themes related to the research questions.  

 The success of this Spanish language programme can be understood in terms of several factors such as whānau support, programme leadership, quality teachers, international excursions and positive attitudes to foreign language learning.  

These findings will contribute to literature concerning additional language learning programmes, specifically those based in indigenous language immersion settings and they will also provide useful information and ideas which other Kura Kaupapa Māori can take advantage of when implementing additional international language learning programmes.

year: 2012