title: Low-cost fluid flow sensor to enable electronic control of fractional distillation columns

authors: Scott, Jonathan B.

subjects: sensors

abstract: A sensor is described that measures fluid flow up to 20 ml/minute, and down to 0.001 ml/minute. The measurement involves counting drips as they fall through a pair of optical beams. The beams are formed using a pair of ordinary optical proximity sensors arranged to face each other so that each photo- receiver sees the other sensor’s emitter. The beams operate at two different frequencies so as to prevent reflected signals interfering. Only two sensors, an 8-pin microcontroller, and four resistors are required for the sensing. Calibration for a specific fluid is straightforward. An ethanol-water mixture produces 16 drips/ml, significantly different from the default pharmaceutical value of 12 drips/ml.

text: Low-cost fluid flow sensor to enable electronic control of fractional distillation columns A sensor is described that measures fluid flow up to 20 ml/minute, and down to 0.001 ml/minute. The measurement involves counting drips as they fall through a pair of optical beams. The beams are formed using a pair of ordinary optical proximity sensors arranged to face each other so that each photo- receiver sees the other sensor’s emitter. The beams operate at two different frequencies so as to prevent reflected signals interfering. Only two sensors, an 8-pin microcontroller, and four resistors are required for the sensing. Calibration for a specific fluid is straightforward. An ethanol-water mixture produces 16 drips/ml, significantly different from the default pharmaceutical value of 12 drips/ml.

year: 2021

title: Policy reform and labour demand in branches of Sri Lankan manufacturing industry

authors: Gibson, John

subjects: Sri Lankan manufacturing industry

abstract: Many policy reforms in developing countries aim to remove factor market distortions. Whether such reforms reduce unemployment depends partly on the substitution possibilities between labour and other factors of production. This paper examines labour demand in seven branches of Sri Lankan manufacturing industry, using data on 4-digit industrial categories over the 1990 to 1997 period. The Box-Cox transformation is used to allow for flexible, and data-dependent, elasticities. The elasticity of capital-labour substitution varies widely across the branches of industry and is usually variable rather than constant. The average, long-run own-wage elasticity of labour demand for the manufacturing sector is estimated as -0.80, so factor price policy should have an important effect on labour demand in this setting.

text: Policy reform and labour demand in branches of Sri Lankan manufacturing industry Many policy reforms in developing countries aim to remove factor market distortions. Whether such reforms reduce unemployment depends partly on the substitution possibilities between labour and other factors of production. This paper examines labour demand in seven branches of Sri Lankan manufacturing industry, using data on 4-digit industrial categories over the 1990 to 1997 period. The Box-Cox transformation is used to allow for flexible, and data-dependent, elasticities. The elasticity of capital-labour substitution varies widely across the branches of industry and is usually variable rather than constant. The average, long-run own-wage elasticity of labour demand for the manufacturing sector is estimated as -0.80, so factor price policy should have an important effect on labour demand in this setting.

year: 2006

title: Kaupapa Māori framework and literature review of key prinicples

authors: Kennedy, Nathan

subjects: New Zealand

abstract: The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

text: Kaupapa Māori framework and literature review of key prinicples The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

year: 2009-06-30