title: Pulse-shaping feed-forward-compensated generator

authors: Seshadri, Sinduja

abstract: A typical electrical stimulator has a battery, step-up converter, voltage regulator, pulse generator with a micro-controller providing the clocking signal. This outputs a step response with a specified amplitude and pulse-width. In this work, Single-Ended Primary Inductance Converter (SEPIC) and Cuk converter are built to output a step response without the requirement of a voltage regulator and a pulse generator. The transfer function of both instruments predict a step response that will overshoot but settle to steady-state. This is true when the drive is of a fixed duty cycle. We show that the overshoot can be reduced or completely removed by sending an irregular pulse waveform to the drive, determined from the transfer function of the converters. Sufficiently adjusting the duty cycles of drive pulses forces the converter to rapidly reach steady-state value. As a result, a programmable converter delivers a well-formed pulse of specific length without the need for additional circuitry.

text: Pulse-shaping feed-forward-compensated generator A typical electrical stimulator has a battery, step-up converter, voltage regulator, pulse generator with a micro-controller providing the clocking signal. This outputs a step response with a specified amplitude and pulse-width. In this work, Single-Ended Primary Inductance Converter (SEPIC) and Cuk converter are built to output a step response without the requirement of a voltage regulator and a pulse generator. The transfer function of both instruments predict a step response that will overshoot but settle to steady-state. This is true when the drive is of a fixed duty cycle. We show that the overshoot can be reduced or completely removed by sending an irregular pulse waveform to the drive, determined from the transfer function of the converters. Sufficiently adjusting the duty cycles of drive pulses forces the converter to rapidly reach steady-state value. As a result, a programmable converter delivers a well-formed pulse of specific length without the need for additional circuitry.

year: 2019-05-20

title: CPI bias and real living standards in Russia during the transition

authors: Gibson, John

subjects: CPI bias

abstract: The economies of the former Soviet Bloc experienced large declines in output during the decade of transition which began with the collapse of the Soviet Union in 1991. Yet there are many reasons to believe that measured output and official deflators provide a poor proxy for the change in real living standards in transition economies. This paper uses the Engel curve methodology recently developed by Hamilton (2001) and Costa (2001) to examine changes in real living standards in Russia during the transition period and to provide an estimate of how much the officialRussian CPI has overstated consumer inflation. We also examine changes in consumer durables, home production, and subjective well-being to further evaluate changes in living standards. Our findings indicate that CPI bias has caused a substantial understatement of the growth performance of the Russian economy during the transition. Even just allowing household final consumption to be deflated with bias, we find that the level of real per capita GDP in 2001 may be understated by up to thirty percent compared with using a bias-corrected deflator. Our analysis of consumer durables, home production, and subjective well-being supports the conclusion that the decline in living standards has been substantially less than what is inferred by looking at official statistics on real output.

text: CPI bias and real living standards in Russia during the transition The economies of the former Soviet Bloc experienced large declines in output during the decade of transition which began with the collapse of the Soviet Union in 1991. Yet there are many reasons to believe that measured output and official deflators provide a poor proxy for the change in real living standards in transition economies. This paper uses the Engel curve methodology recently developed by Hamilton (2001) and Costa (2001) to examine changes in real living standards in Russia during the transition period and to provide an estimate of how much the officialRussian CPI has overstated consumer inflation. We also examine changes in consumer durables, home production, and subjective well-being to further evaluate changes in living standards. Our findings indicate that CPI bias has caused a substantial understatement of the growth performance of the Russian economy during the transition. Even just allowing household final consumption to be deflated with bias, we find that the level of real per capita GDP in 2001 may be understated by up to thirty percent compared with using a bias-corrected deflator. Our analysis of consumer durables, home production, and subjective well-being supports the conclusion that the decline in living standards has been substantially less than what is inferred by looking at official statistics on real output.

year: 2004-09

title: Waitangi Soda Springs alum dosing – Bioavailability of aluminium 2011-2020

authors: Ling, Nicholas

abstract: Continuous alum dosing of the Waitangi Soda Springs at Lake Rotoehu commenced in 2011 to reduce inflows of dissolved reactive phosphorus to Lake Rotoehu. Analyses of bioaccumulation in the tissues of kōura and goldfish from Lake Rotoehu were undertaken on animals collected annually since 2013 to determine the bioavailability and bioaccumulation of aluminium. Lake Rotoehu kōura and goldfish collected in 2013 showed slightly elevated aluminium concentrations in the gills indicating enhanced exposure to aluminium but little evidence for significant bioaccumulation in tissues. Concentrations in goldfish liver and gills were highest in 2016, but not significantly different to goldfish collected from Lake Rotorua in 2013 and flesh concentrations were low. Analyses of animals collected in 2020 confirm these earlier findings with no evidence of enhanced bioaccumulation of aluminium in Lake Rotoehu biota.

text: Waitangi Soda Springs alum dosing – Bioavailability of aluminium 2011-2020 Continuous alum dosing of the Waitangi Soda Springs at Lake Rotoehu commenced in 2011 to reduce inflows of dissolved reactive phosphorus to Lake Rotoehu. Analyses of bioaccumulation in the tissues of kōura and goldfish from Lake Rotoehu were undertaken on animals collected annually since 2013 to determine the bioavailability and bioaccumulation of aluminium. Lake Rotoehu kōura and goldfish collected in 2013 showed slightly elevated aluminium concentrations in the gills indicating enhanced exposure to aluminium but little evidence for significant bioaccumulation in tissues. Concentrations in goldfish liver and gills were highest in 2016, but not significantly different to goldfish collected from Lake Rotorua in 2013 and flesh concentrations were low. Analyses of animals collected in 2020 confirm these earlier findings with no evidence of enhanced bioaccumulation of aluminium in Lake Rotoehu biota.

year: 2021