Academic literature on the topic 'Analyzer for equivalent level of carbon dioxide index'

The rising concentration of carbon dioxide in the atmosphere ([CO2]) has a direct effect on terrestrial vegetation through shifts in the rates of photosynthetic carbon uptake and transpirational water-loss. Free Air CO2 Enrichment (FACE) experiments aim to predict the likely responses of plants to increased [CO2] under normal climatic conditions. The Giessen FACE system operates a lower [CO2] enrichment regime (480 μmol mol–1) than standard FACE (550–600 μmol mol–1), permitting the analysis of a mixed species temperate meadow under a [CO2] level equivalent to that predicted in 25–30 years. We analysed the physiological and morphological responses of six species to investigate the effect of moderate [CO2] on spring biomass production. Carbon dioxide enrichment stimulated leaf photosynthetic rates and supressed respiration, contributing to enhanced net assimilation and a 23% increase in biomass. The capacity for photosynthetic assimilation was unaffected by [CO2] enrichment, with no downregulation of rates of carboxylation of Rubisco or regeneration of ribulose-1,5-bisphosphate. Foliar N content was also not influenced by increased [CO2]. Enhanced [CO2] reduced stomatal size, but stomatal density and leaf area index remained constant, suggesting that the effect on gas exchange was minimal.

Muay Thai is a martial art that requires complex skills and tactical excellence for success. However, the energy demand during a Muay Thai competition has never been studied. This study was devised to obtain an understanding of the physiological capacities underlying Muay Thai performance. To that end, the aerobic energy expenditure and the recruitment of anaerobic metabolism were assessed in 10 male athletes during a simulation match of Muay Thai. Subjects were studied while wearing a portable gas analyzer, which was able to provide data on oxygen uptake, carbon dioxide production, and heart rate (HR). The excess of CO2 production (CO2 excess) was also measured to obtain an index of anaerobic glycolysis. During the match, group energy expenditure was, on average (mean ± standard error of the mean), 10.75 ± 1.58 kcal·min–1, corresponding to 9.39 ± 1.38 metabolic equivalents. Oxygen uptake and HRs were always above the level of the anaerobic threshold assessed in a preliminary incremental test. CO2 excess showed an abrupt increase in the first round, and reached a value of 636 ± 66.5 mL·min–1. This parameter then gradually decreased throughout the simulation match. These data suggest that Muay Thai is a physically demanding activity with great involvement of both the aerobic metabolism and anaerobic glycolysis. In particular, it appears that, after an initial burst of anaerobic glycolysis, there was a progressive increase in the aerobic energy supply. Thus, training protocols should include exercises that train both aerobic and anaerobic energetic pathways.

Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo–carbon dioxide levels. This paper presents new estimates of palaeo–atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi–quantitative palaeo–carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present–day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo–carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long–term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced concentrations during the Late Carboniferous and Early Permian. Such data are important in demonstrating the long–term responses of plants to changing carbon dioxide concentrations and in contributing to the database needed for general circulation model climatic analogues.

Hollow tin dioxide (S-SnO2) and solid SnO2 (B-SnO2) were prepared by a hydrothermal-calcination method with and without carbon spheres as templates, respectively. The flame retardancy, mechanical and thermal degradation properties, and char residues of the poly(vinyl chloride) samples treated with S-SnO2 and B-SnO2 were contrastively investigated by a limiting oxygen index instrument, cone calorimeter (Cone), tensile properties tests, and thermogravimetric analyzer. When the loading level of SnO2 was 2 phr, the limiting oxygen index of the poly(vinyl chloride) sample treated with S-SnO2 (poly(vinyl chloride)/S-SnO2) increased by 5.3% and 2%, and its elongation is 27.3% and 29.9% higher than that of the blank poly(vinyl chloride) and the poly(vinyl chloride) sample treated with B-SnO2 (poly(vinyl chloride)/B-SnO2), respectively. Compared with the blank poly(vinyl chloride) and the poly(vinyl chloride)/B-SnO2, the total heat release of poly(vinyl chloride)/S-SnO2 decreased by 24.5% and 9.4%, and the peak of smoke production rate decreased by 56.7% and 11.7%, respectively.

Seed marks the beginning of grain production from cultivated crops. Ensuring seed quality is the priority in the field of seed technology. In this context, the purpose of this study was to evaluate the use of carbon dioxide concentration to Classify Brassica napus seed lots of different quality resulting from various sowing dates. Seed lots were evaluated by percentage of normal plantlets and the germination rate index. CO2 concentration was quantified in samples submitted to five periods of incubation at 40° C with the aid of a gas exchange analyzer coupled to an injection and airflow system. The results were subjected to analysis of variance and the mean values were compared by the Duncan test and by regression analysis at the 5% level of significance. B. napus seeds from all lots showed a high percentage of normal plantlets and germination rate index. Percentage of normal plantlets was correlated with CO2 concentration. Determination of the CO2 concentration was more efficient with three hours of incubation which allowed classification of canola seed lots into four vigor classes. CO2 concentration was inversely proportional to the percentage of normal plantlets.

The present paper provides an indication (using selection index theory) of the contribution of genetics to a reduction in methane emissions through the current selection for productivity traits (defined as the inherent rate). This is then compared with potential new approaches that incorporate measurements or estimates of methane production as selection criteria. The predicted value of the inherent reduction in methane at a price (all costs and prices are in Australian dollars) of $25/t carbon dioxide equivalent (CO2-e; methane × 25) is $0.38/cow mated per year. The direct value of the estimated annual genetic gain in productivity (about $3/cow mated) is about eight times the value of the savings in methane. The value of the carbon savings doubles to ~$0.75 if methane yield (methane per unit feed intake) is included in the index. This is due to a reduction in methane emissions of 0.78% of the mean (1.20 kg methane/cow mated per year at a carbon cost of $25/t CO2-e) which increases to 1.0% at $50/t CO2-e. If selection is on methane alone, the annual response is ~1.45%, which is valued at $1.39 at a price of $25/t CO2-e. However, adoption is less than 100% at the breeder level, so that realised gains will be less than predicted here.

Background Upper airway obstruction (UAO) during sedation can often cause clinically significant adverse events. Direct comparison of different drugs' propensities for UAO may improve selection of appropriate sedating agents. The authors used the application of negative airway pressure to determine the pressure that causes UAO in healthy subjects sedated with midazolam or propofol infusions. Methods Twenty subjects (12 male and 8 female) completed the study. After achieving equivalent levels of sedation, the subjects' ventilation, end-tidal gases, respiratory inductance plethysmographic signals, and Bispectral Index values were monitored for 5 min. Negative airway pressure was then applied via a facemask in steps of 3 cm H(2)O from -3 to -18 cm H(2)O. UAO was assessed by cessation of inspiratory airflow and asynchrony between abdomen and chest respiratory inductance plethysmographic signals. Results Equivalent levels of sedation were achieved with both drugs with average (+/- SD) Bispectral Index levels of 75 +/- 5. Resting ventilation was mildly reduced without any changes in end-tidal pressure of carbon dioxide. There was no difference between the drugs in the negative pressure resulting in UAO. Five female subjects and one male subject with midazolam and four female subjects and one male subject with propofol did not show any UAO even at -18 cm H(2)O. Compared with males, female subjects required more negative pressures to cause UAO with midazolam (P = 0.02) but not with propofol (P = 0.1). Conclusions At the mild to moderate level of sedation studied, midazolam and propofol sedation resulted in the same propensity for UAO. In this homogeneous group of healthy subjects, there was a considerable range of negative pressures required to cause UAO. The specific factors responsible for the maintenance of the upper airway during sedation remain to be elucidated.

ABSTRACT Objective: To verify the reproducibility of the six-minute walk test (6MWT) performance and its physiological variables in healthy students. Methods: This is as prospective cross-sectional study. The sample consisted of healthy students aged 6-12 years old from public and private schools in the region of Florianópolis City, Santa Catarina State, (Southern Brazil). The medical state was considered according to the health records and scores on the International Study of Asthma and Allergies in Childhood (ISAAC) and the spirometric values of forced expiratory volume in the first second and forced vital capacity above 80% of what was predicted. Two 6MWTs were conducted with a 30-minute interval between them, following the recommendations from the American Thoracic Society. Physiologic variables were recorded using the portable telemetric gas analyzer K4b2 (Cosmed®, Italy). For analysis, the dyspnea index, the perception of effort and performance variables identified in both 6MWT were considered. Data distribution was verified with the Shapiro-Wilk test and statistical analysis included paired t-test or Wilcoxon test, and intraclass correlation coefficient (ICC). The significance level adopted was 5%. Results: A total of 22 students with a mean age of 10.2±1.5 years participated in the study. The covered distance and the variation of oxygen consumption reproducibility between the two 6MWTs presented ICC=0.76 and ICC=0.86, respectively. There was also similar behavior of the physiological variables when comparing the two tests (p=0.001), especially the minute volume (MV), the oxygen consumption (VO2), and the carbon dioxide production (VCO2). Conclusions: The 6MWT showed reproducible values, both in performance and physiological parameters, in the healthy students analyzed.

AbstractInternational frameworks for greenhouse gas (GHG) mitigation usually disregard country-specific inequalities for the allocation of mitigation burdens. This may hinder low developed regions in a country from achieving development in a socioeconomic perspective, such as the Sustainable Development Goals (SDGs) of eradicating poverty (SDG1) and hunger (SDG2). We use observed data (1991–2010) of carbon dioxide equivalent (CO2eq) emissions and a sub-national human development index (MicroHDI, range [0, 1]) for Brazilian microregions to design a framework where regional mitigation burdens are proportional to the MicroHDI, without compromising national mitigation pledges. According to our results, the less developed Brazilian regions have not been basing their development in emission-intensive activities; instead, the most developed regions have. Between 2011 and 2050, Brazilian cumulative emissions from the sectors most correlated with MicroHDI are expected to be 325 Gt CO2eq, of which only 50 Gt are associated with regions of MicroHDI < 0.8. Assuming a national GHG mitigation target of 56.5% in 2050 over 2010 (consistent with limiting global warming to 2 ºC), Brazil would emit 190 Gt CO2eq instead of 325 Gt and the 135 Gt reduction is only accounted for by regions after reaching MicroHDI ≥ 0.8. Allocating environmental restrictions to the high-developed regions leaves ground for the least developed ones to pursue development with fewer restrictions. Our heterogeneous framework represents a fairer allocation of mitigation burdens which could be implemented under the concepts of green economy. This work could be an international reference for addressing both environmental and socioeconomic development in developing countries at sub-national level as emphasized by the SDGs.

Метою роботи є розробка системи поточного контролю температури, вологості, атмосферного тиску повітря на основі сучасної мікроелектронної компонентної бази, а також моніторингу та аналізу стану забруднення повітря в частині визначення концентрації летючих органічних сполук (TVOC) і еквівалентного рівня діоксиду вуглецю (eCO2). Дипломна робота орієнтована на поглиблене вивчення фізичних методів визначення вмісту найбільших забрудників повітря та передбачає аналіз сучасного стану ринку електронних первинних перетворювачів в названій сфері та контролерів для побудови систем моніторингу та аналізу. В першому розділі дипломної роботи розглянуто нормативну базу в сфері отримання та аналізу інформації про поточний стан атмосферного повітря, проаналізовано відмінності в підходах до індексації якості повітря в Європі та Україні, визначено їх недоліки та переваги. У другому розділі розглянуто методики визначення вмісту основних забрудників повітря та проведено аналіз структурних схем аналізаторів, розглянуто особливості їх ключових конструктивних елементів, проведено порівняння конструкції і архітектури, наведено окремі принципові схеми вимірювання. В третьому розділі розглянуто сучасні типи мікроелектронних первинних перетворювачів фізичних параметрів атмосферного повітря, його хімічного складу та механічних забрудників. Проаналізовано технічні та метрологічні параметри сучасних сенсорних пристроїв з оглядом на відповідність сучасним вимогам, нормам, типам інтерфейсів. За результатами детального вивчення інформації у зазначених областях вибрано мікроелектронні сенсори з цифровим вихідним інтерфейсом для побудови мікроконтролерних системи моніторингу: - сенсор температури, вологості та атмосферного тиску BME 280; - мікромеханічний сенсор абсолютного тиску моделі BMP180 (висоти над рівнем моря) з роздільною здатністю 6 кПа ( відповідає роздільній здатності за зміною висоти 0.5 м) в режимі ультра-низького споживання та 2 hPa кПа ( відповідає зміні висоти 0.17 м) в режимі прецизійного вимірювання; - сенсор комплексного визначення якості повітря Adafruit CCS811 з можливістю визначення рівня летючих органічних сполук та ефективного рівня СО2 (CCS811 - Adafruit CCS811 Air Quality Sensor Breakout - VOC and eCO2) з додатковим вбудованим блоком прецизійного сенсора температури і вологості HDC1080. Для проектування системи моніторингу використано контролер ARDUINO UNO. В роботі запропоновано структурну схему системи і наведено схему підключення кожного з компонентів. Також у третьому розділі розроблено програмний код у програмному середовищі Arduino IDE для підключення окремих компонентів системи моніторингу до мікроконтролера, проведено його налаштування.
The work aim is an air quality system development for temperature, humidity, atmospheric pressure monitoring based on modern microelectronic components, as well as for monitoring and analysis of air pollution in terms of volatile organic compounds (TVOC) and equivalent levels of carbon dioxide and other pollutant gases concentration determination. Thesis is focused on in-depth study of physical methods for determining the the largest air pollutants content, on the electronic sensors current state analysis in this area and controllers choice for monitoring and analysis systems design. The first section of the thesis considers the regulatory framework in the field of obtaining and analyzing information about the atmospheric air current state, analyzes the differences in approaches to air quality indexing in the both Europe and Ukraine, identifies their disadvantages and advantages. The second section considers the methods of the major air pollutants content determining and analyzes the structural schemes of analyzers, considers the features of their key structural elements, compares the design and architecture, provides some basic electronic circuits. The third section considers modern types of atmospheric air physical parameters microelectronic sensors, its chemical composition and mechanical pollutants. The modern sensor technical and metrological parameters are analyzed with regard to compliance with modern requirements, norms, types of interfaces. Based on the results of a detailed study of information in these areas, modern microelectronic sensors with a digital output interface were selected to build microcontroller monitoring systems: - BME280 temperature, humidity and atmospheric pressure sensor; - micromechanical absolute pressure sensor model BMP180 (altitude) with a resolution of 6 kPa (corresponds to a change in altitude 0.5m) in the ultra-low consumption mode and 2 hPa kPa (corresponds to a change in altitude 0.17m) in the mode of precision measurement; - Adafruit CCS811 integrated air quality sensor with the ability to determine the level of volatile organic compounds and effective CO2 level (CCS811 - Adafruit CCS811 Air Quality Sensor Breakout - VOC and eCO2) with an additional built-in unit of precision temperature and humidity sensor HDC1080. The ARDUINO UNO controller was used to design the monitoring system. The structural scheme of the system is offered and the scheme of connection of each of components is resulted in the work. Also the program code in the Arduino IDE software environment for separate components of the monitoring system is developed, its adjustment is carried out.