A Study on the Effect of Storage of Betel Leaves at Ambient Temperature

A research study was conducted for studying the storage of Madras and Kolkata varieties of betel leaves under ambient temperature with different diffusion storage systems were observed for different treatments. In the treatment T1, the concentration of oxygen, O2 reduced to a minimum of 14.27 per cent and carbon dioxide, CO2 concentration increased to 4.80 per cent on the 14th day of storage in ambient condition (28°C). It was also reported that by the 14th day, betel leaves stored at ambient condition maintained satisfactory quality in the entire diffusion channel chambers. For the Kolkatta leaves the treatment T2, the concentration of O2 was reduced to 12.0 per cent and CO2 concentration increased to 7.87 per cent on the 18th day of storage. Compared to other treatments, the O2 concentration was found to be very low and CO2 concentration was high on the 18th day of storage in T2 diffusion channel. Similarly, on the 18th day, betel leaves stored at ambient condition maintained satisfactory quality in all the treatments. Hence, it is clear that from this present study, different varieties of betel leaves will have different rates of respiration for a particular size of the diffusion channel and temperature. In other words, varietal variation occurs concerning respiration rate under identical condition.

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Effect of Nitrogen Gas Packaging on the Quality and Microbial Growth of Fresh-Cut Vegetables under Low Temperatures

Journal of Food Protection ◽

10.4315/0362-028x-65.2.326 ◽

2002 ◽

Vol 65 (2) ◽

pp. 326-332 ◽

Cited By ~ 42

Author(s):

SHIGENOBU KOSEKI ◽

KAZUHIKO ITOH

Keyword(s):

Microbial Growth ◽

Modified Atmosphere Packaging ◽

Co2 Concentration ◽

Coliform Bacteria ◽

Atmospheric Conditions ◽

Psychrotrophic Bacteria ◽

Low Concentrations ◽

O2 Concentration ◽

Fresh Cut ◽

Carbon Dioxide Co2

Nitrogen (N2) gas packaging for fresh-cut vegetables (lettuce and cabbage) has been examined as a means of modified atmosphere packaging (MAP) for extending the shelf life of cut vegetables. Gas composition in enclosed packages that contained cut vegetables and were filled with 100% N2 had an oxygen (O2) concentration of 1.2 to 5.0% and a carbon dioxide (CO2) concentration of 0.5 to 3.5% after 5 days of storage. An atmosphere of low concentrations of O2 and high CO2 conditions occurred naturally in the package filled with N2 gas. Degradation of cut vegetables in terms of appearance was delayed by N2 gas packaging. Because of this effect, the appearance of fresh-cut vegetables packaged with N2 gas remained acceptable at temperatures below 5°C after 5 days. Treatment with acidic electrolyzed water (AcEW) contributed to the acceptability of the vegetables' appearance at 5 and 10°C in the air-packaging system. N2 gas packaging did not significantly affect the growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) in or on cut vegetables at 1, 5, and 10°C for 5 days. Microbial growth in or on the cut vegetables was inhibited at 1°C for 5 days regardless of atmospheric conditions.

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The Synergistic Effect of PM2.5 and CO2 Concentrations on Occupant Satisfaction and Work Productivity in a Meeting Room

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18084109 ◽

2021 ◽

Vol 18 (8) ◽

pp. 4109

Author(s):

Jindong Wu ◽

Jiantao Weng ◽

Bing Xia ◽

Yujie Zhao ◽

Qiuji Song

Keyword(s):

Air Quality ◽

Synergistic Effect ◽

Work Productivity ◽

Co2 Concentration ◽

Human Beings ◽

Meeting Room ◽

Negative Effect ◽

Carbon Dioxide Co2 ◽

Occupant Satisfaction ◽

Pm2.5 Concentration

High indoor air quality is crucial for the health of human beings. The purpose of this work is to analyze the synergistic effect of particulate matter 2.5 (PM2.5) and carbon dioxide (CO2) concentration on occupant satisfaction and work productivity. This study carried out a real-scale experiments in a meeting room with exposures of up to one hour. Indoor environment parameters, including air temperature, relative humidity, illuminance, and noise level, were controlled at a reasonable level. Twenty-nine young participants were participated in the experiments. Four mental tasks were conducted to quantitatively evaluate the work productivity of occupants and a questionnaire was used to access participants’ satisfaction. The Spearman correlation analysis and two-way analysis of variance were applied. It was found that the overall performance declined by 1% for every 10 μg/m3 increase in PM2.5 concentration. Moreover, for every 10% increase in dissatisfaction with air quality, productivity performance decreased by 1.1% or more. It should be noted that a high CO2 concentration (800 ppm) has a stronger negative effect on occupant satisfaction towards air quality than PM2.5 concentration in a non-ventilated room. In order to obtain optimal occupant satisfaction and work productivity, low concentrations of PM2.5 (<50 μg/m3) and CO2 (<700 ppm) are recommended.

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The Exploitation of Local Vitis vinifera L. Biodiversity as a Valuable Tool to Cope with Climate Change Maintaining Berry Quality

Plants ◽

10.3390/plants10010071 ◽

2020 ◽

Vol 10 (1) ◽

pp. 71

Author(s):

María Carmen Antolín ◽

María Toledo ◽

Inmaculada Pascual ◽

Juan José Irigoyen ◽

Nieves Goicoechea

Keyword(s):

Climate Change ◽

Fruit Quality ◽

Atmospheric Carbon Dioxide ◽

Antioxidant Properties ◽

Co2 Concentration ◽

Soluble Solids ◽

Vitis Vinifera L ◽

Grape Quality ◽

Berry Quality ◽

Carbon Dioxide Co2

(1) Background: The associated increase in global mean surface temperature together with raised atmospheric carbon dioxide (CO2) concentration is exerting a profound influence on grapevine development (phenology) and grape quality. The exploitation of the local genetic diversity based on the recovery of ancient varieties has been proposed as an interesting option to cope with climate change and maintaining grape quality. Therefore, this research aimed to characterize the potential fruit quality of genotypes from seven local old grapevine varieties grown under climate change conditions. (2) Methods: The study was carried out on fruit-bearing cuttings (one cluster per plant) that were grown in pots in temperature gradient greenhouses (TGG). Two treatments were applied from fruit set to maturity: (1) ambient CO2 (400 ppm) and temperature (T) (ACAT) and (2) elevated CO2 (700 ppm) and temperature (T + 4 °C) (ECET). (3) Results: Results showed that some of the old genotypes tested remained quite stable during the climate change conditions in terms of fruit quality (mainly, total soluble solids and phenolic content) and of must antioxidant properties. (4) Conclusion: This research underlines the usefulness of exploiting local grapevine diversity to cope with climate change successfully, although further studies under field conditions and with whole plants are needed before extrapolating the results to the vineyard.

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A Numerical Simulation of Gas Jet Diffusion Flames Enveloped by a Cascade of Venturis

Volume 2: 19th Computers and Information in Engineering Conference ◽

10.1115/detc99/cie-9046 ◽

1999 ◽

Author(s):

Ala R. Qubbaj ◽

S. R. Gollahalli

Keyword(s):

Diffusion Flames ◽

Co2 Concentration ◽

Reaction Model ◽

Numerical Results ◽

Pollutant Emissions ◽

Gas Jet ◽

University Of Oklahoma ◽

Burner Exit ◽

Baseline Case ◽

O2 Concentration

Abstract “Venturi-cascading” technique has been developed in the Combustion Laboratory at the University of Oklahoma. The goal was to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A propane jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, mid-flame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO2 concentration by 35%, 37%. and 32%, respectively, than the baseline flame. An opposite trend was noticed for O2 concentration; the cascaded flame has higher O2 concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The simulated results were compared with the experimental data. Good agreement was found in the near-burner region. However, the agreement was poor in the downstream regions. The numerical results substantiate the conclusion, which was drawn in the experimental part of this study, that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to interpret the experimental measurements and understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism plays an important role besides the conventional thermal-NO mechanism.

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Hypoxia-induced changes in shivering and body temperature

Journal of Applied Physiology ◽

10.1152/jappl.1987.62.6.2477 ◽

1987 ◽

Vol 62 (6) ◽

pp. 2477-2484 ◽

Cited By ~ 48

Author(s):

H. Gautier ◽

M. Bonora ◽

S. A. Schultz ◽

J. E. Remmers

Keyword(s):

Central Nervous System ◽

Body Temperature ◽

Room Temperature ◽

Co2 Concentration ◽

Hypoxic Conditions ◽

O2 Concentration ◽

The Central Nervous System ◽

Induced Changes ◽

Maintain Body Temperature ◽

Ambient Hypoxia

Experiments were carried out on conscious cats to evaluate the general characteristics and modes of action of hypoxia on thermoregulation during cold stress. Intact and carotid-denervated (CD) conscious cats were exposed to ambient hypoxia (low inspired O2 fraction) or CO hypoxia in prevailing laboratory (23–25 degrees C) or cold (5–8 degrees C) environments. In the cold, both groups promptly decreased shivering and body temperature when exposed to either type of hypoxia. Small increases in CO2 concentration reinstituted shivering in both groups. At the same inspired concentration of O2, CD animals decreased shivering and body temperature more than intact cats. While this difference resulted, in part, from a lower alveolar PO2 in CD cats, a difference between intact and CD cats was apparent when the two groups were compared at the same alveolar PO2. During more prolonged hypoxia (45 min), shivering returned but did not reach normoxic levels, and body temperature tended to stabilize at a hypothermic value. Exposure to various levels of hypoxia produced graded suppression of shivering, with the result that the change in body temperature varied directly with inspired O2 concentration. Hypoxia appears to act on the central nervous system to suppress shivering and sinus nerve afferents appear to counteract this direct effect of hypoxia. In intact cats, this counteraction appears to be sufficient to maintain body temperature under hypoxic conditions at room temperature but not in the cold.

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Effect of Graphene Nanoplatelet on the Carbonation Depth of Concrete under Changing Climate Conditions

Applied Sciences ◽

10.3390/app11199265 ◽

2021 ◽

Vol 11 (19) ◽

pp. 9265

Author(s):

Yingzi Zhang ◽

Yanze Wang ◽

Mingqian Yang ◽

Huatao Wang ◽

Guofang Chen ◽

...

Keyword(s):

Control Sample ◽

Co2 Concentration ◽

Favorable Effect ◽

Carbonation Depth ◽

Graphene Nanoplatelet ◽

Carbonation Reaction ◽

Climate Conditions ◽

Ordinary Concrete ◽

Changing Climate ◽

Carbon Dioxide Co2

Climate change has been unprecedented in the past decades or even thousands of years, which has had an adverse impact on the mechanical properties of concrete structures. Many researchers have begun to study new concrete materials. Graphene nanoplatelet (GNP) is an attractive nanomaterial that can change the crystal structure of concrete and improve durability. The aim of the present study was to investigate the effect of GNP (0.05%wt) on the carbonation depth of concrete under simulated changing climate conditions (varying temperature, relative humidity, and carbon dioxide (CO2) concentration), and compare it with ordinary concrete. When the concentration of CO2 is variable, the carbonation depth of graphene concrete is 10% to 20% lower than that of ordinary concrete. When the temperature is lower than 33 °C, the carbonation depth of graphene concrete is less than that of the control sample; however, above 33 °C, the thermal conductivity of GNP increases the carbonation reaction rate of concrete. When the humidity is a variable, the carbonation depth of graphene concrete is less than 15% to 30% of ordinary concrete, and when the humidity is higher than 78%, the difference in the carbonation depth between the ordinary concrete and the graphene concrete decreases gradually. The overall results indicated that GNP has a favorable effect on anti-carbonation performance under changing climate conditions.

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Multi-Year Comparison of CO2 Concentration from NOAA Carbon Tracker Reanalysis Model with Data from GOSAT and OCO-2 over Asia

Remote Sensing ◽

10.3390/rs12152498 ◽

2020 ◽

Vol 12 (15) ◽

pp. 2498

Author(s):

Farhan Mustafa ◽

Lingbing Bu ◽

Qin Wang ◽

Md. Arfan Ali ◽

Muhammad Bilal ◽

...

Keyword(s):

Time Series ◽

Spatial Distribution ◽

Atmospheric Carbon Dioxide ◽

Carbon Budget ◽

Co2 Concentration ◽

Mitigation Strategies ◽

Spatial Correlations ◽

Western Asia ◽

Carbon Dioxide Co2 ◽

Good Agreement

Accurate knowledge of the carbon budget on global and regional scales is critically important to design mitigation strategies aimed at stabilizing the atmospheric carbon dioxide (CO2) emissions. For a better understanding of CO2 variation trends over Asia, in this study, the column-averaged CO2 dry air mole fraction (XCO2) derived from the National Oceanic and Atmospheric Administration (NOAA) CarbonTracker (CT) was compared with that of Greenhouse Gases Observing Satellite (GOSAT) from September 2009 to August 2019 and with Orbiting Carbon Observatory 2 (OCO-2) from September 2014 until August 2019. Moreover, monthly averaged time-series and seasonal climatology comparisons were also performed separately over the five regions of Asia; i.e., Central Asia, East Asia, South Asia, Southeast Asia, and Western Asia. The results show that XCO2 from GOSAT is higher than the XCO2 simulated by CT by an amount of 0.61 ppm, whereas, OCO-2 XCO2 is lower than CT by 0.31 ppm on average, over Asia. The mean spatial correlations of 0.93 and 0.89 and average Root Mean Square Deviations (RMSDs) of 2.61 and 2.16 ppm were found between the CT and GOSAT, and CT and OCO-2, respectively, implying the existence of a good agreement between the CT and the other two satellites datasets. The spatial distribution of the datasets shows that the larger uncertainties exist over the southwest part of China. Over Asia, NOAA CT shows a good agreement with GOSAT and OCO-2 in terms of spatial distribution, monthly averaged time series, and seasonal climatology with small biases. These results suggest that CO2 can be used from either of the datasets to understand its role in the carbon budget, climate change, and air quality at regional to global scales.

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Effect of Greenhouse CO2 Supplementation on Yield and Mineral Element Concentrations of Leafy Greens Grown Using Nutrient Film Technique

Agronomy ◽

10.3390/agronomy10030323 ◽

2020 ◽

Vol 10 (3) ◽

pp. 323 ◽

Cited By ~ 1

Author(s):

Hardeep Singh ◽

Megha R. Poudel ◽

Bruce L. Dunn ◽

Charles Fontanier ◽

Gopal Kakani

Keyword(s):

Dry Weight ◽

Co2 Concentration ◽

Greenhouse Production ◽

Leafy Greens ◽

Greenhouse Study ◽

Nutrient Film Technique ◽

Swiss Chard ◽

Photosynthetic Assimilation ◽

Carbon Dioxide Co2 ◽

Hydroponically Grown

Carbon dioxide (CO2) concentration is reported to be the most important climate variable in greenhouse production with its effect on plant photosynthetic assimilation. A greenhouse study was conducted using a nutrient film technique (NFT) system to quantify the effect of two different levels of CO2 (supplemented at an average of 800 ppm and ambient at ~410 ppm) on growth and nutritional quality of basil (Ocimum basilicum L.) ‘Cardinal’, lettuce (Lactuca sativa L.) ‘Auvona’, and Swiss chard (Beta vulgaris L.) ‘Magenta Sunset’ cultivars. Two identical greenhouses were used: one with CO2 supplementation and the other serving as the control with an ambient CO2 concentration. The results indicate that supplemented CO2 could significantly increase the height and width of hydroponically grown leafy greens. Supplemented CO2 increased the fresh weight of basil ‘Cardinal’, lettuce ‘Auvona’, and Swiss chard ‘Magenta Sunset’ by 29%, 24.7%, and 39.5%, respectively, and dry weight by 34.4%, 21.4%, and 40.1%, respectively. These results correspond to a significant reduction in Soil Plant Analysis Development (SPAD) and atLEAF values, which represent a decrease in leaf chlorophyll content under supplemented CO2 conditions. Chlorophyll, nitrogen (N), phosphorus (P), and magnesium (Mg) concentrations were generally lower in plants grown in supplemented CO2 conditions, but the results were not consistent for each species. Supplemented CO2 reduced tissue N concentration for basil ‘Cardinal’ and lettuce ‘Auvona’ but not Swiss chard, while Mg concentration was reduced in supplemented CO2 for Swiss chard ‘Magenta Sunset’ only. In contrast, Fe concentration was increased under supplemented CO2 for basil ‘Cardinal’ only. These findings suggest CO2 supplementation could increase yield of leafy greens grown with hydroponics and have varying impact on different mineral concentrations among species.

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Indoor Environmental Quality Evaluation of Lecture Classrooms in an Institutional Building in a Cold Climate

Sustainability ◽

10.3390/su11236591 ◽

2019 ◽

Vol 11 (23) ◽

pp. 6591 ◽

Cited By ~ 7

Author(s):

Lexuan Zhong ◽

Jing Yuan ◽

Brian Fleck

Keyword(s):

Environmental Quality ◽

Co2 Concentration ◽

Sound Level ◽

Cold Climate ◽

Indoor Environmental Quality ◽

Ann Model ◽

University Of Alberta ◽

Artificial Neural Network Ann ◽

Carbon Dioxide Co2 ◽

The University

In this paper, ventilation, indoor air quality (IAQ), thermal and acoustic conditions, and lighting were studied to evaluate the indoor environmental quality (IEQ) in an institutional building at the University of Alberta in Edmonton, Canada. This study examined IEQ parameters, including pressure, illuminance, acoustics, carbon dioxide (CO2) concentration, temperature, and humidity, with appropriate monitors allocated during a lecture (duration 50 min or 80 min) in four lecture classrooms repeatedly (N = 99) from October 2018 to March 2019 with the objectives of providing a comprehensive analysis of interactions between IEQ parameters. The classroom environments were maintained at 23 ± 1 °C and 33% ± 3% RH during two-season measurements. Indoor mean CO2 concentrations were 550–1055 ppm, and a mean sound level of 58 ± 3 dBA was observed. The air change rates were configured at 1.3–6.5 per hour based on continuous CO2 measurements and occupant loads in the lectures. A variance analysis indicated that the within-lecture classroom variations in most IEQ parameters exceeded between-lecture classrooms. A multilayer artificial neural network (ANN) model was developed on the basis of feedforward networks with a backpropagation algorithm. ANN results demonstrated the importance of the sequence of covariates on indoor conditions (temperature, RH, and CO2 level): Air change rate (ACR) > room operations (occupant number and light system) > outdoor conditions.

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Direct Catalytic Conversion of CO2 to Cyclic Organic Carbonates under Mild Reaction Conditions by Metal—Organic Frameworks

Catalysts ◽

10.3390/catal9010034 ◽

2019 ◽

Vol 9 (1) ◽

pp. 34 ◽

Cited By ~ 16

Author(s):

Seong Huh

Keyword(s):

Metal Organic Framework ◽

Cycloaddition Reaction ◽

Co2 Concentration ◽

Reaction Conditions ◽

Catalytic Systems ◽

Heterogeneous Catalytic ◽

Electrochemical Conversion ◽

Modern Chemical ◽

Metal Organic ◽

Carbon Dioxide Co2

The reduction of the representative greenhouse gas, carbon dioxide (CO2), is significantly an important theme for the current research in the modern chemical world. For the last two decades, the development of new metal-organic framework (MOF) systems with highly selective capture of CO2, in the presence of other competing gaseous molecules, has flourished to capture or separate CO2 for environmental protection. Nonetheless, the ultimate resolution to lessen the atmospheric CO2 concentration may be in the chemical or electrochemical conversion of CO2 to other compounds. In this context, the catalytic cycloaddition reaction of CO2 into organic epoxides to produce cyclic carbonates is a more attractive method. MOFs are being proven as efficient heterogeneous catalytic systems for this important reaction. In this review, we collected very recent progress in MOF-based catalytic systems, fully operable under very mild reaction conditions (room temperature and 1 atm CO2).

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