Levels Of CO2 Production Research Articles

Integrating insulated concrete form (ICF) with solar-driven reverse osmosis desalination for building integrated energy storage in cold climates

This research addresses the pressing global challenges of clean energy and water supplies, emphasizing the need for sustainable solutions for the building sector. The study integrates Reverse Osmosis (RO) systems with building energy systems, incorporating Solar Thermal Collectors (STC)/Photovoltaic Thermal (PVT), water-to-water heat pumps, and an Insulated Concrete Form (ICF) based building foundation wall thermal energy storage. It explores the effectiveness of four configurations—STC-ICF, STC-ICF-RO, PVT-ICF, and PVT-ICF-RO—using sensitivity analysis on collector area (25 % and 50 % increase) and weather data from four Canadian cities: Winnipeg, Toronto, Halifax, and Vancouver and two non-Canadian cities: Helsinki, Finland and Bergen, Norway. Key outcomes highlight the benefits of integrated RO scenarios, such as reduced ICF wall temperature, diminished unwanted heat in the cooling season, reduced RO pump consumption, and enhanced solar energy production. The STC-ICF-RO and PVT-ICF-RO systems achieved energy savings of 653 kWh and 131 kWh, respectively, compared to their non-integrated RO counterparts. Both systems also contributed to lowering CO2 production levels. The STC-ICF-RO system's payback period is 2 years, affirming its economic viability. Compared to the base system without ICF and RO integration, the STC-ICF-RO and PVT-ICF-RO configurations reduced energy consumption by 20 % and 32 %, respectively. The sensitivity analysis suggests potential system improvements under specific conditions, primarily when implemented in communities of buildings.

Evolution history and the importance of genomic diversity facing climate change. The case of Agave marmorata Roezl., a microendemic agave used for mezcal production

Social Impact StatementFor hundreds of years, Agave marmorata plants have been used in the production of alcoholic beverages in Mexico. This species is very important in small‐scale rural economies because it is a large plant, yielding five liters of mezcal. However, the production of these beverages takes place when it reaches its reproductive stage, which takes up to 35 years. Due to its slow maturation and high demand, it is considered an endangered species. Therefore, as a conservation strategy, this study proposes the creation of nurseries, genetic breeding programs, and demographic monitoring of wild populations to counteract the extraction of wild plants and, the conservation of the genetic diversity.Summary Agave marmorata Roezl., is an endemic species distributed in the states of Oaxaca and Puebla, Mexico, and locally is widely used to produce mezcal. We assessed the genomic diversity and differentiation using the RADseq method and 29,101 high‐quality single nucleotide polymorphisms (SNPs) in wild plants and grown under three different management types (cultivated, plants used as live fences, and young plants growing in nurseries). We examined the demographic history and used species distribution modeling to understand the future of A. marmorata under scenarios of climate change. We found high levels of genomic diversity (HS = 0.229) and moderate levels of inbreeding (FIS = 0.106 and Fhat3 = 0.190). The cultivated samples harbored less genetic diversity than the wild plants. Furthermore, we estimated low differentiation between cultivated and wild localities (FST = 0.037). In the wild samples, we identified two main genetic groups, one in the East and another in the West of its distribution area. This genetic structure possibly derived from a population contraction during the Pleistocene (~216,879.75 BP) and the formation of two refugia in small areas with climatic stability. Furthermore, the demographic reconstruction indicated that A. marmorata went through a recent population expansion event, with a large current Ne (Ne = 8,009). The future climate change models indicated contrasting possible changes in its distribution range, from an increase to the reduction of its suitable habitat, differences related to model parametrization, and future levels of CO2 production. We propose conservation measures for the different management types of the species while also considering the biotic and abiotic interactions of Agave marmorata.

Yeast and Respiration Rates: To what extent does Saccharomyces cerevisiae, baker’s yeast, CO2 production levels (as measured in ppm) vary with the length of different sugars?

Saccharomyces cerevisiae, or baker’s yeast, is commonly used for baking alongside sucrose. It is understood that yeast’s reaction with sugar leads to a high emission of carbon dioxide, ultimately increasing the height of baked goods. However, the carbon dioxide production levels at different chains of sugars, including sucrose, glucose, and starch, or monosaccharides, disaccharides, and polysaccharides, is not well-known. Water was tested as a control group. The paper hypothesizes that as length of the sugar polymer chain increases, the production of carbon dioxide of Saccharomyces cerevisiae, or baker’s yeast, increases. While the results showed a linear trend similar to the hypothesis, the production levels for the starch experimental group were lower than any other experimental group. This paper concludes that there is no statistical difference between the lengths of the sugar chain and the carbon dioxide production rate can be rejected

Influence of the Environmental Isotope Composition Modification on Growth and Metabolic Activity of Rhodococcus and Saccharomyces

The level of CO2 production and the growth dynamics of the biomass of Rhodococcus erythropolis VKM Ac2017D (Russia) and the yeast strain Saccharomyces cerevisiae OenofermC2 (France) were determined in cultivation media with variously reduced (from 10 to 150 ppm) deuterium concentration. The maximum increase in the rhodococcal biomass was shown in the media with a deuterium concentration of 50 ppm or less. It was noted that the production of CO2 as an integral indicator of the biological activity of cells is more pronounced in Rhodococcus compared to the yeast. With generally similar dynamics of CO2 emission curves, prokaryotes showed broader temporal dynamics of its production.

Optimization of Biogas Production from Organic Municipal Waste: Development of Activated Sludge as Digesters Inoculum

This study is a contribution to the optimization of organic fraction of municipal waste bioconversion into biomethane, by activated sludge production as inoculum for digesters. The wastewater (WW) and cow dung (CD) samples were taken from the slaughterhouse of Ouagadougou town, Burkina Faso. Different mixtures were made, enriched with mineral solution and cellulose at 5% (w/v) as: 10% CD + 90% WW (C7), 30% CD + 70% WW (C6), 50% CD + 50% WW (C5), 70% CD + 30% WW (C4), 90% CD + 10% WW (C3), 100% CD (C2) and 100% WW (C1). The pH evolution and biogas (CH4 and CO2) production were followed for 25 days. Cultures tend to acidify with increase in cow dung proportion. Biogas production was significantly higher (p < 0.05) in C5 (880.0 mL), C6 (862.0 10 mL) and C7 (772.0 mL). Mixture C5 had a highest level of CO2 production (40%). Also C7 and C6 retained in the experiment contained respectively organic matter, volatile fatty acids (VFA) and total alkalinity (TAC) as 41.06%, 47.02%, 1320 mg acetic acid/L, 3036 mg Acetic acid/L and 520 mg CaCO3/L, 1310 mg CaCO3/L. Mixture C6 was the best medium for microorganism proliferation stability with 3.5 × 105 UFC/ml of methanogens bacteria. It also possessed buffering capacity, which prevents acidification of medium during VFAs production.

Unconventional bacterial association for dough leavening

The purpose of the research was to obtain innovative yeast-free doughs leavened by Zymomonas mobilis and Lactobacillus sanfranciscensis. Z. mobilis, as well as Saccharomyces cerevisiae, produces an equimolar mixture of ethanol and CO2 through glucose, fructose or sucrose fermentation. In the present work, the inability of Z. mobilis to metabolize maltose has been circumvented by the addition of L. sanfranciscensis in the formulation. Indeed, L. sanfranciscensis, a heterofermentative lactic acid bacterium (LAB) typical of sourdough environment, hydrolyzes maltose releasing glucose which can be used by Z. mobilis for its metabolism.Biomass samples of Z. mobilis subs. mobilis DSM 424 and L. sanfranciscensis DSM 20663 were grown separately in liquid media and then associated in a model dough. Leavening trials set up by using three different microbial combinations (Lactobacillus:Zymomonas 80+80mg, 15+145mg and 145+15mg biomass, i.e. 1:1, 1:10 and 10:1 respectively on cell dry weight basis) evidenced CO2 production levels (mL) higher than the mathematical sum of CO2 produced by the single bacteria. In particular, when the biomass combination of L. sanfranciscensis and Z. mobilis was 1:1 (80+80mg cdw) and 10:1 (145+15mg cdw) a CO2 production of 46.3–41.4mL versus 26.7–28.5mL was achieved. The calculated productivity gain showed positive performances of the microbial combination up to 180–240min leavening. The subsequent efficiency loss may be due several factors, above all glucose shortage for Z. mobilis, as well as decrease of dough pH that can negatively affect both Lactobacillus and Zymomonas metabolism. As in traditional sourdoughs, L. sanfranciscensis was responsible for the souring activity with positive effects on both dough tasting and reduction of spoilage microbiota; Z. mobilis was instead responsible for most of the CO2 production.A bakery product leavened with the unconventional association Z. mobilis - L. sanfranciscensis will be addressed to people having adverse responses to the ingestion of bakery goods, thus providing innovation in the area of yeast-free leavened food.

Individual variation and repeatability of methane production from dairy cows estimated by the CO2 method in automatic milking system

The objectives of this study were to investigate the individual variation, repeatability and correlation of methane (CH4) production from dairy cows measured during 2 different years. A total of 21 dairy cows with an average BW of 619±14.2 kg and average milk production of 29.1±6.5 kg/day (mean±s.d.) were used in the 1st year. During the 2nd year, the same cows were used with an average BW of 640±8.0 kg and average milk production of 33.4±6.0 kg/day (mean±s.d.). The cows were housed in a loose housing system fitted with an automatic milking system (AMS). A total mixed ration was fed to the cows ad libitum in both years. In addition, they were offered concentrate in the AMS based on their daily milk yield. The CH4 and CO2 production levels of the cows were analysed using a Gasmet DX-4030. The estimated dry matter intake (EDMI) was 19.8±0.96 and 23.1±0.78 (mean±s.d.), and the energy-corrected milk (ECM) production was 30.8±8.03 and 33.7±5.25 kg/day (mean±s.d.) during the 1st and 2nd year, respectively. The EDMI and ECM had a significant influence (P<0.001) on the CH4 (l/day) yield during both years. The daily CH4 (l/day) production was significantly higher (P<0.05) during the 2nd year compared with the 1st year. The EDMI (described by the ECM) appeared to be the key factor in the variation of CH4 release. A correlation (r=0.54) of CH4 production was observed between the years. The CH4 (l/day) production was strongly correlated (r=0.70) between the 2 years with an adjusted ECM production (30 kg/day). The diurnal variation of CH4 (l/h) production showed significantly lower (P<0.05) emission during the night (0000 to 0800 h). The between-cows variation of CH4 (l/day, l/kg EDMI and l/kg ECM) was lower compared with the within-cow variation for the 1st and 2nd years. The repeatability of CH4 production (l/day) was 0.51 between 2 years. In conclusion, a higher EDMI (kg/day) followed by a higher ECM (kg/day) showed a higher CH4 production (l/day) in the 2nd year. The variations of CH4 (l/day) among the cows were lower than the within-cow variations. The CH4 (l/day) production was highly repeatable and, with an adjusted ECM production, was correlated between the years.

Substrate use and survival of fungal plant pathogens on maize residues at winter temperatures around freezing point

Climate scenarios predict increasing temperatures and higher precipitation rates in late autumn to early spring, both of which holding the potential to change the dynamics of plant residue decomposition and overall microbial activity in soil. In company with consequences for nutrient release patterns influences on the survival of fungal plant pathogens and their phytopathogenicity can be expected. Both, litter decomposition and pathogen survival, was analyzed in a 70-day litterbag incubation experiment. Continuous +4 °C was compared to permanent frost (−3 °C) and different freeze-thaw cycles for the decomposition of maize residues and disease potential of soil-borne plant pathogens Fusarium culmorum, Fusarium graminearum, and Rhizoctonia solani. Frost generally reduced maize residue decomposition. On the lower levels of CO2 production in the permanent or occasionally frost treatments pathogen inoculation had large effects on microbial maize use, indicating high saprotrophic activity of pathogens even in cold winter scenarios. Pathogen inoculation led to higher amino sugar contents of maize residue dwelling microbial organisms. At constant 4 °C remarkable high amounts of glucosamine were detected, indicating higher substrate use efficiency without frost. Both, temperature treatments as well as intra- and interspecific competition directed the development of pathogens after inoculation. F. culmorum took large advantage from the non-frost scenario, while no significant increase was found under continuous frost. F. graminearum was also able to increase its abundance at +4 °C. But this was strongly reduced when F. graminearum was in competition to the other two pathogens. In summary, F. culmorum was found to be highly frost tolerant and competitive against F. graminearum, particularly under conditions of freeze-thaw cycles since F. culmorum was able to take a large share of saprotrophic litter residue use under the cold conditions. Biomass of R. solani was strongly decomposed in all treatments. We conclude that constant mild conditions during winter can increase biomass of F. culmorum and F. graminearum in crop residues, causing increased infection pressure in the next season. In contrast to that, frost and freeze-thaw events can lower the build-up of Fusarium biomass and thus diminish the risk of crop infection.

A Potential 17- β Estradiol degrader Bacterium Isolated from Sewage water

A successful 17 β estradiol (E2) degrading bacterium was isolated from waste water of Saft Elhena drain in Egypt. Molecular identification of the isolated bacteria was carried out using DNA (RAPD), the amplification was made by restriction analysis of amplified 16s rDNA and sequencing. Alos, the bacterium was incubated in saline media under different levels of 17 β-estradiol anaerobically. Levels of CO2 production were examined by GC and residual 17 β-estradiol was tested by HPLC to measure biodegradation capacity. Identification of the genetic element responsible of the gene resistance in the bacteria was tested. The sequence analysis of 16S rRNA gene for 17 β estradiol degrader bacterium showed that its affiliations to phylum Enterobacteriaceae, and it belonged to the genera Klebsiella sp. Results revealed that Klebsilla was cabable of degrading estradiol and that the responsible resistance gene was mostly the chromosomal gene. However, further studies are still going on to locate and examine the gene responsible for E2 resistance.

WISE/NEOWISE PRELIMINARY ANALYSIS AND HIGHLIGHTS OF THE 67P/CHURYUMOV-GERASIMENKO NEAR NUCLEUS ENVIRONS

On January 18-19 and June 28-29 of 2010, the Wide-field Infrared Survey Explorer (WISE) spacecraft imaged the Rosetta mission target, comet 67P/Churyumov-Gerasimenko. We present a preliminary analysis of the images, which provide a characterization of the dust environment at heliocentric distances similar to those planned for the initial spacecraft encounter, but on the outbound leg of its orbit rather than the inbound. Broad-band photometry yields low levels of CO2 production at a comet heliocentric distance of 3.32 AU and no detectable production at 4.18 AU. We find that at these heliocentric distances, large dust grains with mean grain diameters on the order of a millimeter or greater dominate the coma and evolve to populate the tail. This is further supported by broad-band photometry centered on the nucleus, which yield an estimated differential dust particle size distribution with a power law relation that is considerably shallower than average. We set a 3-sigma upper limit constraint on the albedo of the large-grain dust at <= 0.12. Our best estimate of the nucleus radius (1.82 +/- 0.20 km) and albedo (0.04 +/- 0.01) are in agreement with measurements previously reported in the literature.

Do Root Exudates Enhance Peat Decomposition?

Despite the importance of understanding controls on microbial carbon (C) mineralization in peat soils, the role of vascular plant root exudates is still unclear. To determine whether root exudates could stimulate enhanced decomposition of peat, we utilized an in-vitro method involving the addition of a solution similar to root exudates (6 glucose-C: 2 citrate-C: 2 amino acid-C, at 3 addition levels) to peat, incubating the mixture and measuring CO2 produced over 20 d and microbial biomass and dissolved organic carbon (DOC) at the end of the incubation. We defined priming as inorganic C (IC) production (CO2 + calculated dissolved inorganic C) during the incubation being greater than that attributed to the control peat plus the added C. An addition level of 0.083 mg C g−1 dry peat, estimated to represent root exudation over one 12-h sunny day in a bog, caused an enhancement in IC production that exceeded that produced in the controls and the amount of added C after 8 d, with rates levelling to control values after 15 d. At the end of the incubation nearly 3 times the amount added C had been mineralized, relative to the control, however this represented only 4% of total microbial respiration in the controls. Although the priming effect pattern appeared to be real throughout repeated measurements in our experiments, the statistical probabilities were not always large due to high variability in background CO2 production levels. Given the observed long lag-times and overall small magnitude and large variability in observed effects, we conclude that although priming of decomposition appears to occur in peatlands, it likely has only a minor overall impact on net C loss to the atmosphere.

Selection of starter cultures for idli batter fermentation and their effect on quality of idlis

Idli batter samples were prepared using lactic starter cultures like Pediococcus pentosaceus (Pp), Enterococcus faecium MTCC 5153 (Ef), Ent. faecium (IB2 Ef-IB2), individually, along with the yeast culture, Candida versatilis (Cv). Idli batter prepared using Ef and Ef-IB2 cultures gave better results, when evaluated for the rise in batter volume (80ml), level of CO2 production (23.8%), titratable acidity 2.4-3.5% (lactic acid) and pH4.3-4.4. Storage stability of batter made with selected starter cultures was determined by analyzing the idlis prepared using the batter stored for 1 and 5days for texture, nutrient composition and sensory quality. Slight variations in the results were seen among the idlis of different combination of cultures, whereas these results are better than that of the idlis made using naturally fermented idli batter. Sensory profile of idlis prepared using starter cultures had a higher score (3.9-4.4) compared to the control (3.6) for overall acceptability.

Catalytic wet peroxide oxidation of phenolic solutions over Fe2O3/CeO2 and WO3/CeO2 catalyst systems

Abstract Fe2O3/CeO2 and WO3/CeO2 catalysts were synthesized with different metal loading (5–20%), using a simple combustion preparation method. The samples were tested in a batch reactor at atmospheric pressure, in a temperature range of 60–100 °C, for 4 h. Phenol conversion and CO2 production levels were evaluated. Iron-containing samples were comparatively more active, reaching a 100% phenol conversion at 80–100 °C. The systems were considerably stable in the acidic reaction medium: low iron leaching levels (1–5%) were registered. Selectivity towards complete mineralization was high (75–80%) and similar for both types of catalytic systems.

EFFECTS OF DECREASING OXYGEN LEVELS IN THE STORAGE ATMOSPHERE ON THE RESPIRATION OF IDARED APPLES

Based on the concept of dynamic CA-storage, the effect of decreasing oxygen levels in the storage atmosphere has been assessed for ‘Idared’ apples, taking into account the harvest date, storage duration and storage conditions of the sample fruit prior to measurements (regular atmosphere (RA) or low oxygen (LO)-conditions at 4°C). For all sample fruit tested, an anaerobic compensation point (ACP) could be detected, which is the O2 concentration below which CO2 production increased significantly. Level of CO2 production below the ACP was dependent on rate of oxygen reduction, degree of maturity, storage duration of the sample fruit and the previous storage conditions. For fruit stored under RA-conditions, the ACP shifted towards higher oxygen levels after 5–9 months of storage.

Asymbiotic nitrogen fixation in the litter and surface soil of a Pinus laricio Poiret forest (Sila, Calabria, Italy)

Abstract Nitrogen fixation was measured in a Corsican pine (Pinus laricio Poiret) forest in Calabria (Southern Italy). Acetylene reduction activity (ARA) and CO2 production levels were determined by incubation of litter and superficial (0–5 cm) soil layer samples in the field, at monthly intervals. ARA variations were not correlated to those of substrate moisture, air temperature and microbial respiration. In fact N2 fixation presented phases of different intensity which irregularly followed each other. Both litter and soil showed similar rates of N2 fixation. Based on a C2H2:N2 ratio of 3:1 0.8 Kg N ha–1 y–1 in each layer are fixed in the Pinus laricio forest, thus contributing to the N status of the soil in this nutrient–poor forest.

Is the hyperpnea of muscular contractions critically dependent on spinal afferents?

We studied the role of spinal afferent pathways in the hyperpnea of electrically induced muscle contractions (ExE). The ventilatory (VE) and arterial CO2 partial pressure (PaCO2) responses were measured at rest and during two levels of ExE in awake human paraplegic subjects with clinically complete lesions of the spinal cord (range T4-T11). We hypothesized that if peripheral neural drive is critical to a normal ventilatory response, then ExE in the absence of intact pathways should cause a lower ventilatory response resulting in hypercapnia at the onset of ExE. ExE was induced by stimulation of the quadriceps and hamstring muscles that approximately doubled the resting level of CO2 production (VCO2). PaCO2 during work transitions and in the latter stages of ExE did not differ significantly from that at rest. Arterial pH progressively declined over time during ExE (P less than 0.01) as a result of increased lactate concentration (P less than 0.01). The linear relationship between VE and VCO2 was similar to that found for normal human subjects during ExE (P = 0.73). These data suggest that VE and presumably alveolar ventilation (VA) can be appropriately matched to VCO2 during low-intensity muscle contractions of the lower extremities in the absence of intact spinal afferent pathways. Moreover, since it is unlikely that postulated "central command" mechanisms were initiated during ExE in these paraplegic subjects, the data provide support for our previous conclusion that central command is not obligatory for matching VA to VCO2 (J. Appl. Physiol. 64: 218-225, 1988).

CO2 elimination as a function of frequency and tidal volume in rabbits during HFO.

CO2 elimination (VCO2) was monitored during high-frequency oscillation (HFO) over a frequency (f) range of 2-30 Hz in anesthetized and paralyzed rabbits to determine whether effective gas exchange could be achieved in this species, to determine the f and tidal volume (VT) dependence of gas exchange in this species, and to compare these results with those from dog and human studies. We were able to produce VCO2 levels during HFO that exceeded normal steady-state levels of CO2 production with VT's less than the total dead space volume. VCO2 was related to f in a curvilinear fashion, whereas in some rabbits VCO2 became independent of f at higher frequencies. This curvilinear relationship between f and VCO2 is similar to data from humans but contrasts with the linear relationship found in dogs. Evidence is presented indicating frequency-dependent behavior of gas exchange is correlated with a frequency-dependent decrease in respiratory system resistance. We propose that the frequency-dependent mechanical properties of the rabbit lung may also account for the species differences in HFO gas exchange.

Production of carbon dioxide in vitro by blastocysts from intact and ovariectomized mice.

'Normal' and 'delayed implanting' mouse blastocysts were incubated in non-radioactive culture medium for various lengths of time (preincubation), and then placed in culture medium with (14-C)-glucose for 2 hr. The rate of embryonic CO-2 given off by the blastocysts. Normal embryos were unaffected by the length of preincubation. By contrast, 'delayed implantating' embryos had a low level of CO-2 production with short preincubations (i.e. less than 2 hr), but approached the normal range with longer preincubations (i.e. more than 8 hr) and thus, were 'activated ' in vitro. Incubation of the 'delayed implanting' embryos with actinomycin D prevented the expected increase in CO-2 production, indicating that synthesis of new RNA is necessary for their activation. Preincubation of normal and 'delayed implanting' blastocysts with oestradiol-17 beta and/ or progesterone had no effect on the level of CO-2 production, suggesting that the hormones do not directly stimulate or inhibit carbohydrate metabolism in the embryos.