Data Acquisiton and Transmission System for Carbon Dioxide Analysis

Despite being a minor part of the atmosphere's composition, the so-called greenhouse gases play a crucial role in their thermodynamics. Over the past 200 years, however, human activities have significantly altered the global carbon cycle. Thus, in the current context of global warming, quantifying, with increasingly reliable values, greenhouse gas emissions and the global carbon cycle has become one of scientists’ priorities. This study aims to develop a system for acquisition and wireless transmission of carbon dioxide data from the C-Sense, a sensor manufactured by Turner Designs. As result, a reliable, compact and versatile circuit has been developed that acts as an embedded system for monitoring CO2 concentration and partial pressure, as well as two temperature variables. Regarding the transmission of data via radio frequency, its data transmission has a range of 470 m without loss. A Python script has been implemented that stores data and generates real-time graphs for system monitoring.

Direct Solid Oxide Electrolysis of Carbon Dioxide: Analysis of Performance and Processes

Chemical industries rely heavily on fossil resources for the production of carbon-based chemicals. A possible transformation towards sustainability is the usage of carbon dioxide as a source of carbon. Carbon dioxide is activated for follow-up reactions by its conversion to carbon monoxide. This can be accomplished by electrochemical reduction in solid oxide cells. In this work, we investigate the process performance of the direct high-temperature CO2 electrolysis by current-voltage characteristics (iV) and Electrochemical Impedance Spectroscopy (EIS) experiments. Variations of the operation parameters temperature, load, fuel utilization, feed gas ratio and flow rate show the versatility of the procedure with maintaining high current densities of 0.75 up to 1.5 A·cm−2, therefore resulting in high conversion rates. The potential of the high-temperature carbon dioxide electrolysis as a suitable enabler for the activation of CO2 as a chemical feedstock is therefore appointed and shown.

Flow-through Respirometry: The Basics

This chapter describes the basic theory behind the most widely used method for measuring metabolic rates: flow-through or open-system respirometry. The advantages and disadvantages of the technique are summarized and the two major types of flow-through respirometry systems are described. Recommendations are given on choosing an appropriate flow rate to compromise between speed of response and signal amplitude; on the nature and importance of the cage time-constant; on using mathematical techniques for response correction by compensating for first-order wash-out kinetics and avoiding mixing errors; the essential differences between oxygen and carbon dioxide analysis; choosing a data acquisition system; generating and measuring flow rates; removing or mathematically compensating for water vapor; important tools; and checklists for deciding on system configuration for a given investigation.

Constant Volume Techniques Using Gas Analysis

By using modern gas analyzers and variations of constant volume techniques described in Chapter 2, simple and high-throughput measurement of the metabolic rates of organisms ranging in size from bacteria to large insects and even small vertebrates are easily implemented. It is also possible to measure water loss rate and carbon dioxide production using only an oxygen analyzer. These respirometry techniques can be deployed in the field as well as the laboratory. Both manual and automated, computerized implementations of constant volume techniques for metabolic rate measurement are covered in full step-by-step detail, and appropriate analytical protocols for oxygen, carbon dioxide, or both oxygen and carbon dioxide analysis systems are also described in detail.