title: An investigation of milk powder deposition on parallel fins

authors: Walmsley, Timothy Gordon

abstract: One method to reduce the energy consumption of industrial milk spray dryers is to recover waste heat from the exhaust dryer air. A significant challenge associated with this opportunity is the air contains a small amount of powder that may deposit on the face and surfaces of a recuperator. This paper introduces a novel lab based test that simulates powder deposition on a bank of parallel plate fins at exhaust dryer air conditions. The fin bank acts like the face of a typical finned tube row in a recuperator. The aim of this study is to look at how deposition on the front of fins is affected by the air conditions. Results show similar characteristics to other milk powder deposition studies that exhibit a dramatic increase in deposition once critical stickiness levels are reached. As powder deposits on the face of the fins, the pressure drop across the bank increases until eventually an asymptote occurs, at which point the rates of deposition and removal are similar. For very sticky conditions, deposition on the face of the fins can cause a rise in the pressure drop by as much as 65%. The pressure drop has also been successfully related to the percentage of open frontal area of the fins with and without deposition. Deposition inside and at the rear of the fin bank was found to be minimal.

text: An investigation of milk powder deposition on parallel fins One method to reduce the energy consumption of industrial milk spray dryers is to recover waste heat from the exhaust dryer air. A significant challenge associated with this opportunity is the air contains a small amount of powder that may deposit on the face and surfaces of a recuperator. This paper introduces a novel lab based test that simulates powder deposition on a bank of parallel plate fins at exhaust dryer air conditions. The fin bank acts like the face of a typical finned tube row in a recuperator. The aim of this study is to look at how deposition on the front of fins is affected by the air conditions. Results show similar characteristics to other milk powder deposition studies that exhibit a dramatic increase in deposition once critical stickiness levels are reached. As powder deposits on the face of the fins, the pressure drop across the bank increases until eventually an asymptote occurs, at which point the rates of deposition and removal are similar. For very sticky conditions, deposition on the face of the fins can cause a rise in the pressure drop by as much as 65%. The pressure drop has also been successfully related to the percentage of open frontal area of the fins with and without deposition. Deposition inside and at the rear of the fin bank was found to be minimal.

year: 2012-09-23

title: Using absolute metric maps to close cycles in a topological map

authors: Jefferies, Margaret E.

subjects: cognitive mapping

abstract: In simultaneous localisation and mapping (SLAM) the correspondence problem, specifically detecting cycles, is one of the most difficult challenges for an autonomous mobile robot. In this paper we show how significant cycles in a topological map can be identified with a companion absolute global metric map. A tight coupling of the basic unit of representation in the two maps is the key to the method. Each local space visited is represented, with its own frame of reference, as a node in the topological map. In the global absolute metric map these local space representations from the topological map are described within a single global frame of reference. The method exploits the overlap which occurs when duplicate representations are computed from different vantage points for the same local space. The representations need not be exactly aligned and can thus tolerate a limited amount of accumulated error. We show how false positive overlaps which are the result of a misaligned map, can be discounted.

text: Using absolute metric maps to close cycles in a topological map In simultaneous localisation and mapping (SLAM) the correspondence problem, specifically detecting cycles, is one of the most difficult challenges for an autonomous mobile robot. In this paper we show how significant cycles in a topological map can be identified with a companion absolute global metric map. A tight coupling of the basic unit of representation in the two maps is the key to the method. Each local space visited is represented, with its own frame of reference, as a node in the topological map. In the global absolute metric map these local space representations from the topological map are described within a single global frame of reference. The method exploits the overlap which occurs when duplicate representations are computed from different vantage points for the same local space. The representations need not be exactly aligned and can thus tolerate a limited amount of accumulated error. We show how false positive overlaps which are the result of a misaligned map, can be discounted.

year: 2005

title: The social work professionalisation project before the 1990s in Aotearoa New Zealand: The dream

authors: Hunt, Sonya

subjects: social work professionalisation

abstract: INTRODUCTION: The meaning and purpose of social work has always been debated within the social work profession. The profession dreams of contributing towards a better, fairer, civil society locally and internationally. This article explores the professionalisation of social work in Aotearoa New Zealand. This exploration has been undertaken as background for an ongoing research project.

METHOD: A critical consideration of the different theoretical and historical dimensions and interests at work that impacted on the journey of professionalisation of social work in this country has been undertaken based on a review of literature. Part one of the article outlines a definition of social work, and different concepts and approaches to professionalisation. Part two of the article contextualises the different approaches to professionalisation within Aotearoa New Zealand, from early forms of welfare pre-colonisation up until the early 1990s.

CONCLUSION: The literature and trends discussed serve to both document the history of professionalisation of social work in Aotearoa New Zealand and as background to an ongoing critical research project which aims to uncover interests at work and interrogate the legitimacy of those interests, while enabling the voices of key actors from the time to surface, be explored, and be recorded.

text: The social work professionalisation project before the 1990s in Aotearoa New Zealand: The dream INTRODUCTION: The meaning and purpose of social work has always been debated within the social work profession. The profession dreams of contributing towards a better, fairer, civil society locally and internationally. This article explores the professionalisation of social work in Aotearoa New Zealand. This exploration has been undertaken as background for an ongoing research project.

METHOD: A critical consideration of the different theoretical and historical dimensions and interests at work that impacted on the journey of professionalisation of social work in this country has been undertaken based on a review of literature. Part one of the article outlines a definition of social work, and different concepts and approaches to professionalisation. Part two of the article contextualises the different approaches to professionalisation within Aotearoa New Zealand, from early forms of welfare pre-colonisation up until the early 1990s.

CONCLUSION: The literature and trends discussed serve to both document the history of professionalisation of social work in Aotearoa New Zealand and as background to an ongoing critical research project which aims to uncover interests at work and interrogate the legitimacy of those interests, while enabling the voices of key actors from the time to surface, be explored, and be recorded.

year: 2016