title: Heterogeneous Credit Impacts on Health Care Spending of the Poor in Peri-Urban Areas, Vietnam: Quantile Treatment Effect Estimation

authors: Doan, Tinh Thanh

subjects: credit

abstract: Quantile treatment effects are estimated to study the impacts of household credit access on health spending by poor households in one District of Ho Chi Minh City, Vietnam. There are significant positive effects of credit on the health budget shares of households with low health care spending. In contrast, when an average treatment effect is estimated, there is no discernible impact of credit access on health spending. Hence, typical approaches to studying heterogeneous credit impacts that only consider between-group differences and not differences over the distribution of outcomes may miss some heterogeneity of interest to policymakers.

text: Heterogeneous Credit Impacts on Health Care Spending of the Poor in Peri-Urban Areas, Vietnam: Quantile Treatment Effect Estimation Quantile treatment effects are estimated to study the impacts of household credit access on health spending by poor households in one District of Ho Chi Minh City, Vietnam. There are significant positive effects of credit on the health budget shares of households with low health care spending. In contrast, when an average treatment effect is estimated, there is no discernible impact of credit access on health spending. Hence, typical approaches to studying heterogeneous credit impacts that only consider between-group differences and not differences over the distribution of outcomes may miss some heterogeneity of interest to policymakers.

year: 2016

title: Pressure screening studies with wood pulp

authors: Weeds, Zuben

subjects: Wood-pulp Refining Separation

abstract: Pressure screening is used in paper making to separate components of a wood pulp slurry (water, wood fibre and solid contaminant material) and to concentrate the wood fibre. The complex solid-liquid and solid-solid mechanisms involved in pressure screening are still poorly understood. This thesis reviews the literature on pressure screening mechanisms and highlights the problems in the models used to describe pressure screening. 
Two models, based on well-mixed tanks in series, are developed to describe reject thickening behaviour of long and short screens. The first model uses a single one row of tanks to model steady flow from feed to accept and from feed to reject streams of a screen. A back-flow model, which had two rows of well-mixed tanks, one for the feedside and another for the accept-side of the screen, was also developed. The passage ratio for back-flow of fibre PB was estimated numerically by deducing the passage ratio for forward-flow of fibre PF. The model showed that PB can decrease more quickly than PF when feed consistency increases, even when overall passage ratio Pp remains constant. 
A small industrial pressure screen (diameter 203 mm, length 220 mm) was used to investigate the effect of screen length Ls and feed consistency Cf on pressure screening performance. The effects of pulp type ( eucalypt for short fibre and pine kraft pulp for short fibre), feed consistency (from 0.005% to 2% compared to approximately 1 % in industrial plants), screen length and placement along the length of the screen, rotor type (bump or step), and screen hole shape (round holes or slots) were investigated. Measurements of pulp consistency in the feed, reject and accept streams under different processing conditions were used to assess the screen models developed. Screening behaviour of screens less than 220 mm was studied extensively for the first time. 
The tanks-in-series model showed that the effect of screen length on reject thickening could be described as well-mixed tanks in series with plug flow behaviour when the screen was modelled as 100 tanks. The reject thickening factor T decreased semilogarithmically when number of tanks was decreased but increased slightly when the number of tanks was increased. . Reject thickening factor decreases when a screen with 1-mm hole is shortened from 220 mm to 27 mm. This reduction can be attributed mainly to the flow regime changing from plug to mixed flow.
The maximum volumetric accept flow rate Qmax decreased by approximately 30 % when a 55-mm screen section was moved from the feed end to the reject end. 1bis decrease in Qmax was consistent with an axial decrease in relative speed ( difference between rotor tip and pulp suspension in the feed annulus), along with an estimated 33% reduction in the negative pressure pulse PNP along the screen. Overall fibre passage ratio PP also decreased when the screen section was moved to the reject end, or when pulp was accelerated in a feed chamber upstream of the feed annulus. 
The three distinct regions and two critical feed consistencies observed when Cr increased from 0.005% to 2% are postulated to indicate when fibre accumulation on the feed and accept sides of the screen produces screen plugging. The critical Cr for the accept side is about ten times greater than that for the feed side due mainly to the fact that the conical holes have a larger diameter on the accept side so more fibre must accumulate before backflow is hindered. In Region 1 ( crowding number < 1 ), reject thickening is independent of feed consistency and remains constant regardless of rotor type (bump or step) and screen type (smooth holes or contoured slots). In Region 2 (1< crowding number< 60), reject thickening decreases with feed consistency. In Region 3 (crowding number > 60), reject thickening either . decreases with feed consistency or remains constant depending on the ratio of forward to back-flushing flow exhibited by the rotor and as predicted by the two-tanks in series model. For the step rotor with a flow ratio of 2:1 reject thickening is constant with feed consistency regardless of screen type. For the bump rotor with a flow ratio of 5: 1 reject thickening decreases with feed consistency regardless of the screen type.
Fibre-length fractionation index <I> increased with increasing Cr to a maximum at about Ct=0.7% when using a 1-mm smooth-holed screen with a bump rotor or at Ct=2% for a 2.4-mm smooth-holed screen. Fractionation index then decreased with increasing Cf. 
It is recommended that the back-flow model be further developed so that the volumetric flow ratio (ratio of forward flow to back flow) can be calculated from a residence time distribution. It is also recommended that fibre-length fractionation be attempted at various positions along the screen for medium consistency pulp (Cr of 8 to 12%) using unconventionally large holes (3-5 mm).

text: Pressure screening studies with wood pulp Pressure screening is used in paper making to separate components of a wood pulp slurry (water, wood fibre and solid contaminant material) and to concentrate the wood fibre. The complex solid-liquid and solid-solid mechanisms involved in pressure screening are still poorly understood. This thesis reviews the literature on pressure screening mechanisms and highlights the problems in the models used to describe pressure screening. 
Two models, based on well-mixed tanks in series, are developed to describe reject thickening behaviour of long and short screens. The first model uses a single one row of tanks to model steady flow from feed to accept and from feed to reject streams of a screen. A back-flow model, which had two rows of well-mixed tanks, one for the feedside and another for the accept-side of the screen, was also developed. The passage ratio for back-flow of fibre PB was estimated numerically by deducing the passage ratio for forward-flow of fibre PF. The model showed that PB can decrease more quickly than PF when feed consistency increases, even when overall passage ratio Pp remains constant. 
A small industrial pressure screen (diameter 203 mm, length 220 mm) was used to investigate the effect of screen length Ls and feed consistency Cf on pressure screening performance. The effects of pulp type ( eucalypt for short fibre and pine kraft pulp for short fibre), feed consistency (from 0.005% to 2% compared to approximately 1 % in industrial plants), screen length and placement along the length of the screen, rotor type (bump or step), and screen hole shape (round holes or slots) were investigated. Measurements of pulp consistency in the feed, reject and accept streams under different processing conditions were used to assess the screen models developed. Screening behaviour of screens less than 220 mm was studied extensively for the first time. 
The tanks-in-series model showed that the effect of screen length on reject thickening could be described as well-mixed tanks in series with plug flow behaviour when the screen was modelled as 100 tanks. The reject thickening factor T decreased semilogarithmically when number of tanks was decreased but increased slightly when the number of tanks was increased. . Reject thickening factor decreases when a screen with 1-mm hole is shortened from 220 mm to 27 mm. This reduction can be attributed mainly to the flow regime changing from plug to mixed flow.
The maximum volumetric accept flow rate Qmax decreased by approximately 30 % when a 55-mm screen section was moved from the feed end to the reject end. 1bis decrease in Qmax was consistent with an axial decrease in relative speed ( difference between rotor tip and pulp suspension in the feed annulus), along with an estimated 33% reduction in the negative pressure pulse PNP along the screen. Overall fibre passage ratio PP also decreased when the screen section was moved to the reject end, or when pulp was accelerated in a feed chamber upstream of the feed annulus. 
The three distinct regions and two critical feed consistencies observed when Cr increased from 0.005% to 2% are postulated to indicate when fibre accumulation on the feed and accept sides of the screen produces screen plugging. The critical Cr for the accept side is about ten times greater than that for the feed side due mainly to the fact that the conical holes have a larger diameter on the accept side so more fibre must accumulate before backflow is hindered. In Region 1 ( crowding number < 1 ), reject thickening is independent of feed consistency and remains constant regardless of rotor type (bump or step) and screen type (smooth holes or contoured slots). In Region 2 (1< crowding number< 60), reject thickening decreases with feed consistency. In Region 3 (crowding number > 60), reject thickening either . decreases with feed consistency or remains constant depending on the ratio of forward to back-flushing flow exhibited by the rotor and as predicted by the two-tanks in series model. For the step rotor with a flow ratio of 2:1 reject thickening is constant with feed consistency regardless of screen type. For the bump rotor with a flow ratio of 5: 1 reject thickening decreases with feed consistency regardless of the screen type.
Fibre-length fractionation index <I> increased with increasing Cr to a maximum at about Ct=0.7% when using a 1-mm smooth-holed screen with a bump rotor or at Ct=2% for a 2.4-mm smooth-holed screen. Fractionation index then decreased with increasing Cf. 
It is recommended that the back-flow model be further developed so that the volumetric flow ratio (ratio of forward flow to back flow) can be calculated from a residence time distribution. It is also recommended that fibre-length fractionation be attempted at various positions along the screen for medium consistency pulp (Cr of 8 to 12%) using unconventionally large holes (3-5 mm).

year: 2006

title: Te Toi Poto, Te Toi Roa A Critical Evaluation of Māori-State Inclusion in the Ohiwa Harbour Strategy, Aotearoa New Zealand.

authors: Lowry, Amanda

subjects: Māori

abstract: In New Zealand, the State Owned Enterprises Act 1988 [SOE], Local Government Act 2002 [LGA], the Resource Management Act 1991 [RMA] require that government include the voices of Māori, and ensure their contribution to the decision-making processes of local authorities. Accordingly, central and local government have embraced the idea of inclusive partnership as part of policymaking processes informed by shared values both of government and iwi.
Thus, it is not uncommon to see consultations, partnerships and engagement between Māori-state on a range of issues in line with Tikanga and protocols of Māori culture. These transitions reflect contemporary critical policy scholarship that underscores the need to include marginalised voices policymaking, specifically through processes that reflect diverse values. Termed here as ‘procedural inclusion’, these efforts are framed within the wider goal of participatory democracy as part of the efforts to realise an inclusive society. The present research is a critical evaluation of the inclusion of Māori in the processes of policymaking, especially when those processes have been especially designed to be culturally sensitive.
This core objective is developed through the analysis of the case study of iwi/hapū-local government engagement in creating and implementing the Ohiwa Harbour Strategy in New Zealand’s Eastern Bay of Plenty region between 2002- 2008. The strategy engagement, which culminated in a long-term plan to manage and conserve the Ohiwa harbour, is uniquely positioned for this investigation. It is often regarded by its iwi/hapū and local government stakeholders as a success story in iwi/hapū-government engagement. Using a critical qualitative research methodology informed by kaupapa Māori, the study sought to critically evaluate this exemplar of procedural inclusion at multiple levels. At an operational policy level, the research identified the factors that either facilitated or inhibited Māori inclusion in the strategy development process. At another, more substantive level, the study explored the politics of this engagement, and if the goals of procedural inclusion could accommodate the transformative claims of self-determination and kaitiakitanga made by iwi/hapū.
The analysis of interview data with key stakeholders and documents of the strategy process revealed that a range of factors enhance inclusive policymaking for Māori. At a practical level, legislative frameworks, commitment to Tikanga by all parties, and key strategic cultural brokers facilitated the inclusion of Māori, while limited capacity, fear of change and inter-tribal tensions hinder inclusion. The results also show, at another level, that the ability to productively participate in these engagement processes are framed by discursive politics – of the meanings and interpretations emanating from historical contexts, nature of power relationships, and of decisions regarding who represents whom and what is represented. In all, the study points to both advantages and limitations of procedural inclusion. Inclusive policymaking can open possibilities for better management of environmental resources, strengthening Māori political voice, and creating opportunities for livelihoods and with it greater economic and social inclusion. Equally, there are also limits of government-sponsored engagement.
Māori inclusion in policymaking, while positive, does not deliver opportunities for self determination or rangatiratanga in keeping with the Treaty principles of partnership.

text: Te Toi Poto, Te Toi Roa A Critical Evaluation of Māori-State Inclusion in the Ohiwa Harbour Strategy, Aotearoa New Zealand. In New Zealand, the State Owned Enterprises Act 1988 [SOE], Local Government Act 2002 [LGA], the Resource Management Act 1991 [RMA] require that government include the voices of Māori, and ensure their contribution to the decision-making processes of local authorities. Accordingly, central and local government have embraced the idea of inclusive partnership as part of policymaking processes informed by shared values both of government and iwi.
Thus, it is not uncommon to see consultations, partnerships and engagement between Māori-state on a range of issues in line with Tikanga and protocols of Māori culture. These transitions reflect contemporary critical policy scholarship that underscores the need to include marginalised voices policymaking, specifically through processes that reflect diverse values. Termed here as ‘procedural inclusion’, these efforts are framed within the wider goal of participatory democracy as part of the efforts to realise an inclusive society. The present research is a critical evaluation of the inclusion of Māori in the processes of policymaking, especially when those processes have been especially designed to be culturally sensitive.
This core objective is developed through the analysis of the case study of iwi/hapū-local government engagement in creating and implementing the Ohiwa Harbour Strategy in New Zealand’s Eastern Bay of Plenty region between 2002- 2008. The strategy engagement, which culminated in a long-term plan to manage and conserve the Ohiwa harbour, is uniquely positioned for this investigation. It is often regarded by its iwi/hapū and local government stakeholders as a success story in iwi/hapū-government engagement. Using a critical qualitative research methodology informed by kaupapa Māori, the study sought to critically evaluate this exemplar of procedural inclusion at multiple levels. At an operational policy level, the research identified the factors that either facilitated or inhibited Māori inclusion in the strategy development process. At another, more substantive level, the study explored the politics of this engagement, and if the goals of procedural inclusion could accommodate the transformative claims of self-determination and kaitiakitanga made by iwi/hapū.
The analysis of interview data with key stakeholders and documents of the strategy process revealed that a range of factors enhance inclusive policymaking for Māori. At a practical level, legislative frameworks, commitment to Tikanga by all parties, and key strategic cultural brokers facilitated the inclusion of Māori, while limited capacity, fear of change and inter-tribal tensions hinder inclusion. The results also show, at another level, that the ability to productively participate in these engagement processes are framed by discursive politics – of the meanings and interpretations emanating from historical contexts, nature of power relationships, and of decisions regarding who represents whom and what is represented. In all, the study points to both advantages and limitations of procedural inclusion. Inclusive policymaking can open possibilities for better management of environmental resources, strengthening Māori political voice, and creating opportunities for livelihoods and with it greater economic and social inclusion. Equally, there are also limits of government-sponsored engagement.
Māori inclusion in policymaking, while positive, does not deliver opportunities for self determination or rangatiratanga in keeping with the Treaty principles of partnership.

year: 2012