Use of Different Modern Strategies to Reduce the Energy Use and Co2 Emissions In Dwellings'

 

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ABSTRACT

Approximately 50% of global CO2-based productivity is now attributed to the activity of phytoplankton, including ocean-dwelling cyanobacteria. In response to inherent restrictions on the rate of CO2 supply in the aquatic environment, cyanobacteria have evolved a very efficient means of capturing inorganic carbon (C^sub i^), as either CO2 or HCO^sub 3^^sup -^ for photosynthetic carbon fixation. This capturing mechanism, known as a CO2-concentrating mechanism (CCM), involves the operation of active CO2 and HCO^sub 3^^sup -^ transporters and results in the concentration of CO2 around RuBisCO, in a unique microcompartment called the carboxysome. The CCM exhibits two basic physiological states: a constitutive, low-affinity state; and a high-affinity state, which is induced in response to C^sub i^ limitation. Many of the genetic components of the CCM, including genes encoding C^sub i^ transporters, have been identified. It is apparent that the expression of genes encoding the inducible, high-affinity C^sub i^ transporters is particularly sensitive to C^sub i^ availability, and we are now interested in defining how cyanobacterial cells sense and respond to C^sub i^ limitation at the transcriptional level. Current theories include direct sensing of external C^sub i^; sensing of internal C^sub i^-pool fluctuations; and detection of changes in photorespiratory intermediates, carbon metabolites, or redox potential. At present, there is no consensual view. We have investigated the physiological and transcriptional responses of CCM mutants and wildtype strains to pharmacological treatments and various light, O2, and C^sub i^ regimes. Our data suggest that perception of C^sub i^ limitation by a cyanobacterial cell is either directly or indirectly related to the size of the internal C^sub i^ pool within the cell, in an oxygen-dependent manner.

TABLE OF CONTENTS

ABSTRACT2

CHAPTER 1: INTRODUCTION4

Issues and Design Evolution History7

CHAPTER 2: LITERATURE REVIEW9

Current Emissions9

Economic Impact on Ireland12

Irish Law for Energy Production14

Traditional Case 1: hot and dry17

Descriptive Analysis17

Model Setup19

The DECoRuM tool21

Potential for CO2 reduction24

International Context: Residential Energy Efficiency and Consumption26

Building Energy Rating (BER) - Ireland27

Ireland's GHG Emissions29

Forecasting Future Residential GHG Emissions in Ireland32

REFERENCES33

CHAPTER 1: INTRODUCTION

In response to restrictions on the availability of CO2 in aquatic environments, cyanobacteria actively acquire inorganic carbon (C^sub i^), effectively concentrating CO2 around the active site of ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO). The components of this CO2-concentrating mechanism (CCM) as found in the unicellular, freshwater strains Synechococcus sp. strain PCC7942 and Synechocystis sp. strain PCC6803 (hereafter referred to as Synechococcus PCC7942 and Synechocystis PCC6803, respectively) are summarized in Fig. 1. At least four separate Crtransport systems, for the active uptake of both CO2 and HCO^sub 3^^sup -^, are expressed in these cells, including two high-affinity, inducible HCO^sub 3^^sup -^-transport activities: an ABC transporter, BCT1, encoded by the cmp operon (Omata et al. 1999); and an Na^sup +^-dependent HCO^sub 3^^sup -^-uptake activity, encoded by the sbtA gene.

The active transport of CO2 is associated with specialized NDH-1 dehydrogenase complexes that are thought to convert CO2 to HCO^sub 3^^sup -^ within the cell: a constitutive, low-affinity CO2-transport activity, NDH-1^sub 4^, requires the expression of the ndhF4-ndhD4-chpX (cupB) genes whereas ...