10,520 results
Search Results
2. Development of Sulfur Oxides Analysis in the Atmosphere by an Alkaline Filter Paper Method without Toxic Substances
- Author
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Koji Yamashita, Yukihide Shiraishi, Hitoshi Asano, and Harumi Mitsunaga
- Subjects
Atmosphere ,chemistry ,Filter paper ,Environmental chemistry ,chemistry.chemical_element ,Environmental science ,Sulfur ,Analytical Chemistry - Published
- 2018
3. Colorimetric paper-based device for hazardous compounds detection in air and water: A proof of concept
- Author
-
Valeria De Matteis, Rosaria Rinaldi, Gabriele Fella, Laura Mazzotta, Mariafrancesca Cascione, De Matteis, V., Cascione, M., Fella, G., Mazzotta, L., and Rinaldi, R.
- Subjects
water ,02 engineering and technology ,lcsh:Chemical technology ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,Hazardous waste ,colorimetric detection ,Environmental monitoring ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Process engineering ,Instrumentation ,Volume concentration ,environmental monitoring ,Pollutant ,business.industry ,Atmosphere ,010401 analytical chemistry ,Water ,Paper based ,Contamination ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,PAD ,0104 chemical sciences ,Chemical species ,Proof of concept ,atmosphere ,Environmental science ,0210 nano-technology ,business ,Colorimetric detection - Abstract
In the last decades, the increase in global industrialization and the consequent technological progress have damaged the quality of the environment. As a consequence, the high levels of hazardous compounds such as metals and gases released in the atmosphere and water, have raised several concerns about the health of living organisms. Today, many analytical techniques are available with the aim to detect pollutant chemical species. However, a lot of them are not affordable due to the expensive instrumentations, time-consuming processes and high reagents volumes. Last but not least, their use is exclusive to trained operators. Contrarily, colorimetric sensing devices, including paper-based devices, are easy to use, providing results in a short time, without particular specializations to interpret the results. In addition, the colorimetric response is suitable for fast detection, especially in resource-limited environments or underdeveloped countries. Among different chemical species, transition and heavy metals such as iron Fe(II) and copper Cu(II) as well as volatile compounds, such as ammonia (NH3) and acetaldehyde (C2H4O) are widespread mainly in industrialized geographical areas. In this work, we developed a colorimetric paper-based analytical device (PAD) to detect different contaminants, including Fe2+ and Cu2+ ions in water, and NH3 and C2H4O in air at low concentrations. This study is a &ldquo, proof of concept&rdquo, of a new paper sensor in which the intensity of the colorimetric response is proportional to the concentration of a detected pollutant species. The sensor model could be further implemented in other technologies, such as drones, individual protection devices or wearable apparatus to monitor the exposure to toxic species in both indoor and outdoor environments.
- Published
- 2020
4. Reflection on two Ambio papers by P. J. Crutzen on ozone in the upper atmosphere:This article belongs to Ambio’s 50th Anniversary Collection. Theme: Ozone Layer
- Author
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Merete Bilde and Ole John Nielsen
- Subjects
Greenhouse Effect ,Ozone ,P. J. Crutzen ,Supersonic transport ,Geography, Planning and Development ,Political action ,Atmospheric sciences ,Atmosphere ,chemistry.chemical_compound ,Ozone layer ,Montreal Protocol ,Environmental Chemistry ,Stratospheric ozone depletion ,Stratosphere ,Nitrous oxide ,Ecology ,Stratospheric Ozone ,Nuclear explosions ,Chloro-fluoro-carbons ,General Medicine ,Ozone depletion ,Anniversaries and Special Events ,chemistry ,Perspective ,Environmental science - Abstract
We here reflect on two important articles on stratospheric ozone depletion written by P. J. Crutzen (1974) and P. J. Crutzen and D. H. Ehhalt (1977) in the early 1970s. These articles provide a clear description of the stratosphere and the most important chemical reactions involved in stratospheric ozone depletion. They present modeling results and provide recommendations for future research on stratospheric ozone depletion caused by chloro-fluoro-carbons, supersonic transport, nitrous oxide, and nuclear explosions. These two articles represent the beginning of a scientific era, which led to discovery of the Antarctic ozone hole and political action in the form of the Montreal Protocol and its amendments.
- Published
- 2021
5. Investigation of co-pyrolysis characteristics and kinetics of municipal solid waste and paper sludge through TG-FTIR and DAEM
- Author
-
Hongyu Huang, Lixing Ding, Chen Shu, Yan Lin, Shiwen Fang, and Zhen Huang
- Subjects
Residue (complex analysis) ,Materials science ,Municipal solid waste ,Kinetics ,02 engineering and technology ,Activation energy ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,010406 physical chemistry ,0104 chemical sciences ,Catalysis ,Atmosphere ,Chemical engineering ,Physical and Theoretical Chemistry ,0210 nano-technology ,Co pyrolysis ,Instrumentation ,Pyrolysis - Abstract
In order to explore a harmless and resource-based way to treat municipal solid waste (MSW) and paper sludge (PS), the co-pyrolysis MSW and PS was studied in this paper. Firstly, MSW and PS had the lower residue mass, and MSW had higher pyrolysis index under CO2 atmosphere, compared with the one under N2 atmosphere. Hence, the CO2 was used as the carrier gas in the following study. Secondly, under CO2 atmosphere, the co-pyrolysis of MSW and PS with and without MgO were researched. With the increasing of PS ratio, the pyrolysis performance of the blends decreased constantly. MgO act as catalyst could improve the pyrolysis characteristic index of the blends. However, MgO was an inorganic salt and it would affect the synergistic effect of MSW and PS. The curves of online evolutions of all the gas products and the functional groups had an obvious peak at around 500 ℃. The activation energy of the blends in the first step (
- Published
- 2021
6. Determination of Gaseous and Particulate Fluorides in the Atmosphere (Separation and Collection with a Double Paper Tape Sampler)
- Author
-
James P. Lodge
- Subjects
Atmosphere ,Materials science ,Paper tape ,Separation (aeronautics) ,Metallurgy ,Particulates - Published
- 2017
7. Design of Microfluidic Paper-Based Device for the Detection of Nitrogen Dioxide in Atmosphere
- Author
-
Rajeev Kumar Singh, Surya Tiwary, and Yameen Hassan
- Subjects
Pollutant ,business.industry ,Welding ,Combustion ,law.invention ,Atmosphere ,chemistry.chemical_compound ,chemistry ,law ,Nitric acid ,Environmental science ,Nitrogen dioxide ,Acid rain ,Process engineering ,business ,Sulfur dioxide - Abstract
Pollutant gases from industries and certain processes like welding, exhaust of internal combustion engines, use of explosives, use of nitric acid, etc., are the sources of sulfur dioxide (SO2) and nitrogen oxides (NO2 and N2O5) which become the part of atmosphere. The heterogeneous reactions of atmospheric aerosol convert these gases to sulphuric, nitrous, and nitric acids which precipitate as acid rain and thus severely affect human health. In this paper, the design of colorimetric paper-based microfluidic device is presented to detect and quantify nitrogen dioxide (NO2). In order to reduce the cost of device and ease of fabrication, wax printing for fabricating paper-based analytical device (µPAD) is proposed.
- Published
- 2019
8. The Atmosphere of Safety: Freud’s 'Papers on Technique' (1911–1915)
- Author
-
Roy Schafer
- Subjects
Atmosphere ,Environmental science ,Astrobiology - Published
- 2019
9. The Answer to the Comments by Yu. D. Resnyanskii to the Papers by L. Kh. Ingel’ and A. A. Makosko
- Author
-
Kh. Ingel and A. A. Makosko
- Subjects
Fluid Flow and Transfer Processes ,Atmosphere ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorology ,Gravitational field ,010502 geochemistry & geophysics ,01 natural sciences ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
The critical comments to the publications by the authors ofthe present paper that were given in [10] (the publications deal with the possible effects of gravity field inhomogeneities in the atmosphere and ocean) are discussed. In the authors' opinion, some remarks are groundless. At the same time, the authors agree with one of the important remarks that the results of their paper concerning studies of the ocean disturbances are to be reconsidered.
- Published
- 2016
10. Impacts of Elevated Atmospheric CO2 and O3 on Paper Birch (Betula papyrifera): Reproductive Fitness
- Author
-
Elina Vaapavuori, Joseph N.T. Darbah, Mark E. Kubiske, David F. Karnosky, Neil D. Nelson, and Elina Oksanen
- Subjects
Greenhouse Effect ,Short Communication ,lcsh:Medicine ,Germination ,Flowers ,seed production and germination ,lcsh:Technology ,General Biochemistry, Genetics and Molecular Biology ,Trees ,chemistry.chemical_compound ,Ozone ,Dry weight ,Botany ,elevated CO2 and O ,lcsh:Science ,Betula ,General Environmental Science ,Biomass (ecology) ,flowering ,biology ,Reproductive success ,paper birch ,Atmosphere ,lcsh:T ,Reproduction ,lcsh:R ,food and beverages ,General Medicine ,Carbon Dioxide ,biology.organism_classification ,Horticulture ,Catkin ,chemistry ,Seedling ,Shoot ,Carbon dioxide ,Seeds ,lcsh:Q - Abstract
Atmospheric CO2and tropospheric O3are rising in many regions of the world. Little is known about how these two commonly co-occurring gases will affect reproductive fitness of important forest tree species. Here, we report on the long-term effects of CO3and O3for paper birch seedlings exposed for nearly their entire life history at the Aspen FACE (Free Air Carbon Dioxide Enrichment) site in Rhinelander, WI. Elevated CO2increased both male and female flower production, while elevated O3increased female flower production compared to trees in control rings. Interestingly, very little flowering has yet occurred in combined treatment. Elevated CO2had significant positive effect on birch catkin size, weight, and germination success rate (elevated CO2increased germination rate of birch by 110% compared to ambient CO2concentrations, decreased seedling mortality by 73%, increased seed weight by 17%, increased root length by 59%, and root-to-shoot ratio was significantly decreased, all at 3 weeks after germination), while the opposite was true of elevated O3(elevated O3decreased the germination rate of birch by 62%, decreased seed weight by 25%, and increased root length by 15%). Under elevated CO2, plant dry mass increased by 9 and 78% at the end of 3 and 14 weeks, respectively. Also, the root and shoot lengths, as well as the biomass of the seedlings, were increased for seeds produced under elevated CO2, while the reverse was true for seedlings from seeds produced under the elevated O3. Similar trends in treatment differences were observed in seed characteristics, germination, and seedling development for seeds collected in both 2004 and 2005. Our results suggest that elevated CO2and O3can dramatically affect flowering, seed production, and seed quality of paper birch, affecting reproductive fitness of this species.
- Published
- 2007
11. Pyrolysis volatiles and environmental impacts of printing paper in air
- Author
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Jinxiang Chen, Le Pan, Gang Wu, Hao Ren, Juan Xie, and Yong Wang
- Subjects
Atmosphere ,Polymers and Plastics ,Chemistry ,Scientific method ,Environmental chemistry ,Air atmosphere ,chemistry.chemical_element ,Mass spectrometry ,Chemical reaction ,Oxygen ,Pyrolysis - Abstract
Pyrolysis volatiles and the environmental impact of printing paper in an air atmosphere were investigated using pyrolysis-gas chromatography/mass spectrometry and scanning electron microscopy. CO2 and light-pollution products were found to be the major products from pyrolysis volatiles; furthermore, because oxygen participates in the chemical reaction, many of the pyrolysis volatiles emitted during the paper printing process were different from those formed under an N2 atmosphere. Although a small number of the volatiles were moderately toxic products, the concentrations of these volatiles were low. Heat-induced inkless eco-printing (HIEP) was found to take less time than the pyrolysis experiment in this paper and thus resulted in fewer pyrolysis volatiles. Thus, fewer pyrolysis volatiles will be emitted within the practical temperature range; in particular, no carcinogens were emitted in the pyrolysis temperature range of 250–700 °C. Therefore, HIEP was found to be an ecologically and environmentally preferable technology.
- Published
- 2014
12. Comment on the paper 'Mars Express radio occultation data: A novel analysis approach' by Grandin et al. (2014)
- Author
-
Kerstin Peter, G. L. Tyler, Michael K. Bird, Martin Pätzold, Silvia Tellmann, and Bernd Häusler
- Subjects
Physics ,Electron density ,Number density ,010504 meteorology & atmospheric sciences ,Mars Exploration Program ,Geophysics ,Astrophysics ,01 natural sciences ,Atmosphere ,Space and Planetary Science ,0103 physical sciences ,Radio occultation ,010303 astronomy & astrophysics ,Noise (radio) ,0105 earth and related environmental sciences ,Radio Science ,Exosphere - Abstract
In their recent paper, Grandin et al. (2014) claim to have developed a novel approach, principally a ray tracing method, to analyze radio sounding data from occulted spacecraft signals by planetary atmospheres without the usual assumptions of the radio occultation inversion method of a stratified, layered, symmetric atmosphere. They apply their " new approach" to observations of the Mars Express Radio Science (MaRS) experiment and compare their resulting temperature, neutral number density and electron density profiles with those from MaRS, claiming that there is good agreement with the observations. The fact is, however, that there are serious disagreements in the most important altitude ranges. Their temperature profile shows a 30 K shift or a 300σ (1σ standard deviation = 0.1 K for the MaRS profile near the surface) difference towards warmer temperatures at the surface when compared with MaRS while the MaRS profile is in best agreement with the profile from the Mars Climate Data Base V5.0 (MCD V5.0). Their full temperature profile from the surface to 250 km altitude deviates significantly from the MCD V5.0 profile. Their ionospheric electron density profile is considerably different from that derived from the MaRs observations. Although Grandin et al. (2014) claim to derive the neutral number density and temperature profiles above 200 km, including the asymptotic exosphere temperature, it is simply not possible to derive this information from what is essentially noise.
- Published
- 2016
13. Gas transfer properties of wheat gluten coated paper adapted to eMAP of fresh parsley
- Author
-
Carole Guillaume, Emmanuelle Gastaldi, David Guehi, Nathalie Gontard, Ingénierie des Agro-polymères et Technologies Émergentes (UMR IATE), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA), ADEME-AGRICE, ANR [ANR-07-PNRA-029], ANR-07-PNRA-0029,TAILORPACK,Emballages actifs biodégradables adaptés à la conservation des fruits et légumes frais(2007), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
- Subjects
Gas permeation ,030309 nutrition & dietetics ,[SDV]Life Sciences [q-bio] ,Modified atmosphere packaging ,Wheat gluten ,OXYGEN ,03 medical and health sciences ,chemistry.chemical_compound ,RELATIVE-HUMIDITY ,0404 agricultural biotechnology ,Gas transfer ,BARRIER PROPERTIES ,QUALITY ,Food science ,Coated paper ,GREASE RESISTANCE ,Microstructure ,TEMPERATURE ,VEGETABLES ,0303 health sciences ,EDIBLE FILMS ,Chromatography ,04 agricultural and veterinary sciences ,Permeation ,ATMOSPHERE ,040401 food science ,chemistry ,WATER-VAPOR ,Modified atmosphere ,Chlorophyll ,Steady state (chemistry) ,Food Science - Abstract
Gas transfer properties of wheat gluten (WG) coated paper and their ability to fulfil the requirements in eMAP of fresh parsley were studied. Permeation of gases through WG-paper was demonstrated to be RH-dependent and closely related to structural modification in the WG layer. Formation of micro-cracks was evidenced in dry conditions; but when increasing RH, plasticisation occurs within the protein layer and micro-fractures were reduced until disappearance. This reversible phenomenon allowed the WG-layer to recover its integrity at RH higher than 70%, and the WG character to be expressed in such conditions. When used at 20 degrees C and 80% RH as part of the packaging of parsley, modified atmosphere was created and a steady state of 11 kPa O-2 and 4.5 kPa CO2 was reached after 45 h. In such conditions, the overall quality of parsley leaves remained acceptable during 8 days, with only 28% loss of chlorophyll. (C) 2013 Elsevier Ltd. All rights reserved.
- Published
- 2013
14. Specific Ion–Protein Interactions Influence Bacterial Ice Nucleation
- Author
-
Anna T. Kunert, Ulrich Pöschl, Yuki Nagata, Janine Fröhlich-Nowoisky, Azade YazdanYar, Thomas Koop, Ralph Schwidetzky, Max Lukas, Katrin F. Domke, Mischa Bonn, and Konrad Meister
- Subjects
atmospheric chemistry ,Hofmeister series ,Chemie ,010402 general chemistry ,01 natural sciences ,ice nucleation ,Catalysis ,Ion ,law.invention ,Molecular dynamics ,law ,Crystallization ,Aqueous solution ,Full Paper ,Bacteria ,010405 organic chemistry ,Chemistry ,Precipitation (chemistry) ,Atmosphere ,Organic Chemistry ,nonlinear optics ,Ice ,Temperature ,Membrane Proteins ,Water ,General Chemistry ,Full Papers ,0104 chemical sciences ,Chemical physics ,Ice nucleus ,Frost (temperature) - Abstract
Ice nucleation‐active bacteria are the most efficient ice nucleators known, enabling the crystallization of water at temperatures close to 0 °C, thereby overcoming the kinetically hindered phase transition process at these conditions. Using highly specialized ice‐nucleating proteins (INPs), they can cause frost damage to plants and influence the formation of clouds and precipitation in the atmosphere. In nature, the bacteria are usually found in aqueous environments containing ions. The impact of ions on bacterial ice nucleation efficiency, however, has remained elusive. Here, we demonstrate that ions can profoundly influence the efficiency of bacterial ice nucleators in a manner that follows the Hofmeister series. Weakly hydrated ions inhibit bacterial ice nucleation whereas strongly hydrated ions apparently facilitate ice nucleation. Surface‐specific sum‐frequency generation spectroscopy and molecular dynamics simulations reveal that the different effects are due to specific interactions of the ions with the INPs on the surface of the bacteria. Our results demonstrate that heterogeneous ice nucleation facilitated by bacteria strongly depends upon the nature of the ions, and specific ion–protein interactions are essential for the complete description of heterogeneous ice nucleation by bacteria., Effects of ions on bacterial ice nucleation: Freezing droplet experiments, sum‐frequency generation spectroscopy, and molecular dynamic simulations were used to demonstrate that ions can profoundly influence the efficiency of bacterial ice nucleators in a manner that follows the Hofmeister series. The different effects are due to specific interactions of the ions with ice‐nucleating proteins on the surface of the bacteria.
- Published
- 2021
15. Atmospheric conditioning: airport automation, labour and the COVID‐19 pandemic
- Author
-
Weiqiang Lin
- Subjects
Coronavirus disease 2019 (COVID-19) ,business.industry ,media_common.quotation_subject ,Geography, Planning and Development ,Subject (philosophy) ,Regular Papers ,Space (commercial competition) ,Public relations ,Automation ,labour ,Politics ,State (polity) ,COVID‐19 ,Political science ,Pandemic ,atmosphere ,technology ,Regular Paper ,airport infrastructure ,business ,Futures contract ,Earth-Surface Processes ,media_common ,automation - Abstract
This paper contributes to debates on human–technologies relations and labour geographies. It thinks through how the adoption of automation is mediated by the conditioning effects of atmospheres in space. Taking the occassion of the COVID‐19 pandemic, the paper presents a case of how atmospheres are capable of determining the trajectories of automation, and providing the guiding backdrop for technological (un)development. Drawing on 40 semi‐structured interviews conducted with airport labour in Singapore in 2020 at the height of the COVID‐19 pandemic, the paper offers an analysis of how airport workers variously and viscerally capitulate to, abandon, and/or desire to collaborate with automation, in ways that are both unstable and atmospherically implicated. To the extent that these affective responses have the potential to change the course of technological and labour futures in airport infrastructures, atmospheres — especially those deliberately advocated by the state and airport management — are also a political force to be reckoned with. The paper concludes with a discussion on how a focus on atmospheres can push geographic research on automation in productive and interesting directions. It views automation not just as a collection of abstract artefacts, but projects constantly subject to the conditioning effects of invisible atmospheres., This paper contributes to debates on human–technologies relations and labour geographies. It thinks through how the adoption of automation is mediated by the conditioning effects of atmospheres in space. Drawing on 40 semi‐structured interviews conducted with airport labour in Singapore in 2020 during the COVID‐19 pandemic, the paper analyses how airport workers capitulate to, abandon, and/or desire to collaborate with automation in ways that are unstable and atmospherically implicated.
- Published
- 2021
16. Synoptic analysis of the most durable pollution and clean waves during 2009–2019 in Tehran City (capital of Iran)
- Author
-
Farshad Pazhoh and Farzaneh Jafari Hombari
- Subjects
Pollutant ,Pollution ,Original Paper ,Atmospheric Science ,Stable atmosphere ,media_common.quotation_subject ,Air quality index ,humanities ,Troposphere ,Atmosphere ,Polluted air ,Anticyclone ,Durable wave ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Physical geography ,Precipitation ,Sea level ,Tehran ,Water Science and Technology ,media_common - Abstract
The present study was done to analyze and compare synoptic conditions during the most durable pollution and clean waves (MDPW and MDCW) in Tehran City (capital of Iran). For this purpose, air quality index (AQI) data were first obtained during 2009-2019 from the Tehran Air Quality Control Company in Tehran Province. Then, a threshold of (AQI ≤ 101) representing a polluted and unhealthy atmosphere was considered as MDPW, and a threshold of (AQI ≤ 50) representing a clean (good) air was selected as MDCW in Tehran City by identifying the polluted days. The results showed the presence of MDPW during 43 polluted days from November 21, 2010 to January 2, 2011. Intensity and frequency of the polluted days during statistical period showed a decreasing trend that coincided with an increasing trend of precipitation. Analysis of synoptic conditions occurred during 43 days of MDPW indicated penetration of Siberian high-pressure from the east at sea level and extension of sub-tropical anticyclone in mid-level from the west that led to development of an anticyclone circulation with descending and converging flow in Iran and surrounding region. As a result, a calm and sustainable climate and stable concentration of pollutants were observed throughout Tehran City. Backward trajectory of sources and entry route of the polluted air to Tehran City during peak days of pollution showed that desert regions of southern Iraq and central Iran along the southern and southwestern parts played a major role in increasing concentration of pollutants during occurrence of durable wave. Different routes were observed in entry of dusty and the polluted air to Tehran City according to hybrid single-particle Lagrangian integrated trajectory (HY SPLIT) model, but in most of peak days, the areas that were near and adjacent to Tehran City with height of less than 1000 m played a greater role in particle transport. Investigation of instability indices during MDPW showed that in most days of pollution, values of instability intensity were classified into weak class and lower troposphere (1000-850 hPa) compared to higher levels, and degree of stability and calmness of the atmosphere was more. So that, the highest frequency of temperature inversions occurred near the earth's surface.
- Published
- 2021
17. Experimental studies on natural convection open and closed solar drying using external reflector
- Author
-
Athikesavan Muthu Manokar, S. Vasanthaseelan, Ravishankar Sathyamurthy, Paul Durai Leon Dharmadurai, Ali J. Chamkha, Bharathwaaj Ramani, and Abd Elnaby Kabeel
- Subjects
Solar dryer ,Thermal efficiency ,Moisture ,business.industry ,Health, Toxicology and Mutagenesis ,General Medicine ,Solar energy ,Pulp and paper industry ,Pollution ,Renewable energy ,Atmosphere ,Environmental Chemistry ,Environmental science ,Relative humidity ,business ,Water content - Abstract
For low temperature agricultural crop and meat drying, dryers utilizing the renewable energy source (solar energy) appear to be an efficient technique as it is ecofriendly, energy efficient, and available in free of cost. This work presents the experimental investigation on a solar food dryer equipped with external reflectors to enhance the rate of drying efficiency by removing the moisture content available in the anchovy fish. A comparison of conventional open solar drying is carried out to assess the parameters such as drying efficiency, moisture removal rate, and heat energy required for drying the anchovy fish using the modified solar dryer using the natural convection technique. From the experimental results it is observed that the relative humidity greatly influence the rate of drying. The average relative humidity during the experiments using open solar drying is found as 50–65% whereas, the using solar dryer the average relative humidity inside the chamber is found as 20–35%. The relative humidity of the fish using open solar drying is higher as compared to solar dryer drying as the drying products are kept in open atmosphere. The physical examination results on the dried products proved that using a modified solar dryers, the dried product is free from insects, and dust. Also, it is found that the loss of color from the product is a minimum while compared to conventional open solar drying. The results showed that the thermal efficiency of top tray (dryer 1) and bottom tray (dryer 2) is comparatively higher as compared to that of conventional open solar drying and found as 16.73 and 19.34 %, respectively. Results also showed that nearly 20.05% of the energy could be saved using the modified solar dryer as compared to the open solar drying technique.
- Published
- 2021
18. Ageing of oil impregnated thermally upgraded papers
- Author
-
Lars E. Lundgaard, Marit-Helen Glomm Ese, Cecilie Mork Selsbak, and Knut Brede Liland
- Subjects
Atmosphere ,Hydrolysis ,Improved performance ,Argon ,Materials science ,chemistry ,Transformer oil ,chemistry.chemical_element ,Pulp and paper industry ,Water content ,Nitrogen ,Argon atmosphere - Abstract
Investigation of the difference in the ageing process for several thermally upgraded and non-upgraded papers in transformer oil was performed. We observed that the level of nitrogen in the papers is crucial for the resistance towards hydrolysis. One of the papers in the experiment did not fulfil the upgrade specification with respect to the nitrogen level (data sheet). For hydrolysis of wet oil impregnated samples in argon atmosphere the upgraded papers seem to degrade less than non-upgraded papers. The paper with highest level of nitrogen degrades less than those with lower levels. The Insuldur process seems to be the best way of thermally upgrading the paper (Upgrade 1) and this also gives the highest level of nitrogen. For one of the upgraded samples (Upgrade 2) the nitrogen disappears completely after startup and this paper behaves as non-upgraded for the highest temperature. Dry oil impregnated paper (0.2% water content) under argon atmosphere does not seem to be hydrolysed and ages at a very slow rate. In the case of oxidation of dry oil impregnated samples (0.2% water content) in air there are initially no significant difference between non-upgraded and upgraded papers. However, the upgraded papers seem to have an improved performance after the water production from ageing becomes significant. The oxidation activation energy for non-upgraded paper is lower compared to hydrolysis and for upgraded paper this difference is smaller.
- Published
- 2011
19. Carbonation of alkaline paper mill waste to reduce CO2 greenhouse gas emissions into the atmosphere
- Author
-
François Renard, Rafael Pérez-López, J.M. Nieto, German Montes-Hernandez, Laurent Charlet, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Department of Geology, University of Huelva, University of Huelva, Physics of Geological Processes [Oslo] (PGP), Department of Physics [Oslo], Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO)-Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO)-Department of Geosciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO), Laboratoire de Géodynamique des Chaines Alpines (LGCA), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut des Sciences de la Terre (ISTerre), Institut des Sciences de la Terre [2011-2015] (ISTerre [2011-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Central des Ponts et Chaussées (LCPC)-Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut des Sciences de la Terre [2011-2015] (ISTerre [2011-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Central des Ponts et Chaussées (LCPC)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
020209 energy ,Carbonation ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Mineralogy ,02 engineering and technology ,010501 environmental sciences ,engineering.material ,Carbon sequestration ,01 natural sciences ,7. Clean energy ,Portlandite ,Atmosphere ,chemistry.chemical_compound ,Geochemistry and Petrology ,0202 electrical engineering, electronic engineering, information engineering ,Environmental Chemistry ,Greenhouse effect ,Dissolution ,0105 earth and related environmental sciences ,Calcite ,Chemistry ,Pollution ,13. Climate action ,Environmental chemistry ,Greenhouse gas ,engineering - Abstract
International audience; The global warming of Earth's near-surface, air and oceans in recent decades is a direct consequence of anthropogenic emission of greenhouse gases into the atmosphere such as CO2, CH4, N2O and CFCs. The CO2 emissions contribute approximately 60% to this climate change. This study investigates experimentally the aqueous carbonation mechanisms of an alkaline paper mill waste containing about 55 wt% portlandite (Ca(OH)2) as a possible mineralogical CO2 sequestration process. The overall carbonation reaction includes the following steps: (1) Ca release from portlandite dissolution, (2) CO2 dissolution in water and (3) CaCO3 precipitation. This CO2 sequestration mechanism was supported by geochemical modelling of final solutions using PHREEQC software, and observations by scanning electron microscope and X-ray diffraction of final reaction products. According to the experimental protocol, the system proposed would favour the total capture of approx. 218 kg of CO2 into stable calcite/ton of paper waste, independently of initial CO2 pressure. The final product from the carbonation process is a calcite (ca. 100 wt%)-water dispersion. Indeed, the total captured CO2 mineralized as calcite could be stored in degraded soils or even used for diverse industrial applications. This result demonstrates the possibility of using the alkaline liquid–solid waste for CO2 mitigation and reduction of greenhouse effect gases into the atmosphere.
- Published
- 2008
20. Paper Friction -Effect of Real Contact Area
- Author
-
Tatsuo Yamauchi, Jun Sato, and Noriaki Kawashima
- Subjects
Friction effect ,Microscope ,Chemistry ,Plane (geometry) ,business.industry ,General Medicine ,Mechanics ,Measure (mathematics) ,Power (physics) ,law.invention ,Atmosphere ,Optics ,law ,Relative humidity ,Contact area ,business - Abstract
Relating to real contact area against plane smooth surface, effects of the measuring conditions on paper friction, surrounding atmosphere and applied pressure, were examined. An optical interference method using a scanning laser microscope was adopted to measure the real contact area against a plane smooth surface. The estimated contact area of paper is around 1% of nominal area for common papers. The increase in the contact area with increasing relative humidity is considered as a cause of the increase in the friction coefficient with an increase in relative humidity. The contact area of paper generally increased in a ratio of two-thirds power of the apparent pressure over a wide range of pressure. It suggested that contact of paper was generally elastic and this fact was one reason describing the decrease in the coefficient with increasing apparent pressure. However the decrease in the coefficient is little and the frictional behavior of paper can not be fully described by the contact area against a smooth surface.
- Published
- 2008
21. Paper Friction at the Various Measuring Conditions -Effect of Relative Humidity
- Author
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Noriaki Kawashima, Jun Sato, and Tatsuo Yamauchi
- Subjects
Materials science ,Capillary action ,food and beverages ,chemistry.chemical_element ,Humidity ,General Medicine ,humanities ,Atmosphere ,chemistry.chemical_compound ,chemistry ,Critical relative humidity ,Aluminium ,Relative humidity ,Wetting ,Cellulose ,Composite material - Abstract
Friction of commercial papers under dry, moderate and humid atmospheres was examined, comparing with those of cellulose film and aluminum foil. The friction coefficient between different papers generally gave their intermediate value. The coefficient between equal cellulosic materials including paper increased with humidity, while that of aluminum against aluminum was constant irrespective of surrounding humidity. However the surface wetting with a slight amount of water on aluminum caused rapid increase in the coefficient. The capillary force may cause this phenomenon, and the sharp increase of friction between cellulose films in humid atmosphere was similar to that observed with aluminum foils which were wetted with a slight amount of water. These suggest that the capillary force by a slight amount of water may raise frictional force of cellulosic materials including paper at high humidity.
- Published
- 2008
22. Investigation into physical and chemical, antibacterial and antifungal properties of the air environment formed under the influence of natural potassium salts
- Author
-
L. Tsema, A. Shalimov, A. Isaevich, and A. Maksimov
- Subjects
chemistry.chemical_classification ,Potassium ,Sodium ,Potash ,food and beverages ,chemistry.chemical_element ,Salt (chemistry) ,Humidity ,Natural ventilation ,Pulp and paper industry ,law.invention ,Atmosphere ,chemistry ,law ,Environmental science ,Filtration - Abstract
Russia has a huge potential for growing agricultural products. In this regard, the issue of preserving the grown crop and minimizing storage losses, which can reach 30-50%, is very relevant. Currently, there are known methods for storing agricultural crops in storage facilities with active and natural ventilation in piles, bins, containers equipped with an airing system, systems for maintaining and controlling temperature and humidity. However, these methods do not provide high safety of product laid for long-term storage. A promising direction for solving these problems is the use of the bactericidal properties of the air in contact with natural potassium salts. The Verkhnekamskoye Potassium Salt Deposit, one of the largest potash salt deposits located in Russia, contains a third of the world's reserves, which are mainly used for the production of potash fertilizers. However, the unique physical and chemical properties of natural potassium, sodium, and magnesium salts, as well as their mechanical and filtration characteristics, make it possible to significantly expand the scope of their use. In this regard, the paper describes the results of studies into the properties of the atmosphere in contact with natural potassium-magnesium salts and its effect on phytopathogens. The study of the effect of a saline-saturated atmosphere on Phytophthora infestans showed a greater dependence on the humidity of the environment and a greater degree of growth suppression in the atmosphere saturated with salt aeroions. The growth of this phytopathogen was suppressed by 39,5 % at 16% humidity, by 48,3% at 50% humidity, and by 63.1% at 85% humidity. In addition, experiments on storing potatoes in an atmosphere in contact with natural potash salts showed minimal damage to tubers by phytopathogens when using the bulk surface of potassium salt.
- Published
- 2021
23. The changing effects of Alaska’s boreal forests on the climate systemThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming
- Author
-
T. S. Rupp, F. S. Chapin, A. D. McGuire, and Eugénie S. Euskirchen
- Subjects
Global and Planetary Change ,Ecology ,Taiga ,Climate change ,Forestry ,Albedo ,Snow ,Atmosphere ,Boreal ,Climatology ,Environmental science ,Terrestrial ecosystem ,Ecosystem - Abstract
In the boreal forests of Alaska, recent changes in climate have influenced the exchange of trace gases, water, and energy between these forests and the atmosphere. These changes in the structure and function of boreal forests can then feed back to impact regional and global climates. In this manuscript, we examine the type and magnitude of the climate feedbacks from boreal forests in Alaska. Research generally suggests that the net effect of a warming climate is a positive regional feedback to warming. Currently, the primary positive climate feedbacks are likely related to decreases in surface albedo due to decreases in snow cover. Fewer negative feedbacks have been identified, and they may not be large enough to counterbalance the large positive feedbacks. These positive feedbacks are most pronounced at the regional scale and reduce the resilience of the boreal vegetation – climate system by amplifying the rate of regional warming. Given the recent warming in this region, the large variety of associated mechanisms that can alter terrestrial ecosystems and influence the climate system, and a reduction in the boreal forest resilience, there is a strong need to continue to quantify and evaluate the feedback pathways.
- Published
- 2010
24. Variation and correlation between ultraviolet index and tropospheric ozone during COVID-19 lockdown over megacities of India
- Author
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Soumik Saha, Nairita Sengupta, Biswajit Bera, Sumana Bhattacharjee, and Pravat Kumar Shit
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,Cloud cover ,0208 environmental biotechnology ,02 engineering and technology ,Atmospheric sciences ,01 natural sciences ,Wind speed ,Atmosphere ,Troposphere ,chemistry.chemical_compound ,Environmental Chemistry ,Relative humidity ,Tropospheric ozone ,Safety, Risk, Reliability and Quality ,Concentration of O3 ,0105 earth and related environmental sciences ,General Environmental Science ,Water Science and Technology ,Original Paper ,COVID-19 ,020801 environmental engineering ,Megacity ,chemistry ,Environmental science ,Ultraviolet index ,Lockdown phase ,UV index - Abstract
Worldwide spread out of COVID-19 in a short-time has brought a significant decline of road traffic, tourist flow and industrial ventures. During this emergency period, the restricted human dealings with nature have appeared as blessing for health of the total environment. The variation of atmospheric O3 may modulate the range of UV index (UVI) at any region of the earth. The objective of the study is to examine the variation of UV index over the megacities of India with respect to tropospheric O3 level modification during COVID-19 lockdown. The meteorological or environmental data (temperature in °C, gust in km/h, wind speed km/h, relative humidity in %, air pressure in mb and cloud cover in okta) of four selective megacities of India (Kolkata, Chennai, Delhi, Mumbai) during and pre lockdown period have been obtained to comprehend about the variation of UV index and tropospheric O3. The descriptive statistical applications i.e. standard deviation, standard errors and K-means clustering have been done through standard statistical software. In the present study, t-test has been used to understand level of significance of surface O3 and UVI during pre-lockdown (2019) and lockdown (2020) phase. The result shows that the four major megacities in India namely New Delhi, Mumbai, Kolkata and Chennai have experienced the vibrant diminution in terms of the concentration of UV index with slightly increasing the tropospheric O3 level during the lockdown phase. The higher accumulation of O3 during the lockdown in the lower atmosphere of four megacities does not exceed the permissible limit. The excess amount of O3 has remarkably contributed to trap the harmful UV radiation which has lowered the UVI in these worst polluted megacities of India. In the meantime, the prominent reduction of NOx during the lockdown period decreases the titration impact to O3 and this mechanism helps to revitalize the ozone concentration level. The uniqueness of the current study is highlighted the ground reality regarding reduction of UV index and amplification of tropospheric O3 concentration during lockdown phase. This study definitely assists to make new environmental policy, act and law for recover the health of the total environment.
- Published
- 2021
25. The influence of temperature and oxidizing atmosphere on the process of combusting pellets from agricultural and forest biomass in the stream of inert material
- Author
-
Konrad Kaczyński, Katarzyna Kaczyńska, and Piotr Pełka
- Subjects
Inert ,060102 archaeology ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Pellets ,Biomass ,06 humanities and the arts ,02 engineering and technology ,Combustion ,Pulp and paper industry ,Atmosphere ,Fluidized bed ,Oxidizing agent ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,0601 history and archaeology ,Fluidization - Abstract
Wood pellets are a commonly used biomass for energy production. However, due to the growing demand, many entrepreneurs have begun to produce non-wood biomass pellets. During experimental research, the process of combusting pellets of forest and agricultural origin at different furnace temperatures and different oxidizing atmospheres in a two-phase flow with the use of inert material modelling conditions in the upper zone of the fluidized bed reactor was analyzed. Inert material caused very significant differences in the time and mechanism of forest and agro biomass combustion. These differences are mainly associated with problematic phenomena during combustion, including sintering of ashes. The inert material accelerated the mass loss of forest biomass pellets at all temperatures by about 50–60%. In the case of agro biomass, the combustion time at the temperatures of 650 °C and 750 °C was shortened by about 20–30%, and in the case of the temperature of 850 °C, it was extended by about 10%. Increasing the value of the inert material stream resulted in a reduction of the combustion time at all temperatures. Increasing the concentration of oxidant in the atmosphere of combustion caused the reduction of the combustion time of all tested fuels.
- Published
- 2021
26. Securing the volume/volumen: Comments on Stuart Elden's Plenary paper ‘Secure the volume’
- Author
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Peter Adey
- Subjects
Atmosphere ,History ,Sociology and Political Science ,Meteorology ,Volume (thermodynamics) ,Geography, Planning and Development - Published
- 2013
27. The Influence of Paper Wraps on the Quality of 'd'Anjou' Pears after Controlled Atmosphere Storage
- Author
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Stephen R. Drake, D.C. Elfving, and R.D. Gix
- Subjects
Controlled atmosphere ,Ethoxyquin ,biology ,Flesh ,Ripening ,Horticulture ,biology.organism_classification ,Atmosphere ,chemistry.chemical_compound ,chemistry ,Soluble solids ,Carbon dioxide ,Pyrus communis - Abstract
Pears (Pyrus communis `d'Anjou') were packed in six commercial paper wraps (dry; 3% oil; 3% oil with copper and ethoxyquin; 6% oil; 6% oil with ethoxyquin; 9% oil). After packing, the pears were placed in three different controlled atmosphere (CA) storage conditions in commercial CA rooms: 1) 1.5% oxygen (O) and 1% carbon dioxide (CO2); 2) 1.5% O2 and 3% CO2; 3) 1.5% O2 and 1% CO2 for 60 days, 4% O2 for 60 more days and finally 6% O2 for an additional 90 days. Pears were stored in CA for 120 and 210 days, with or without an additional 30 days in regular atmosphere (RA) storage to simulate shipping and handling. Objective quality evaluations were conducted after each storage period and sensory evaluations after 210 days of storage. Paper type influenced both the peel and flesh color of pears before and after ripening, but did not influence firmness, soluble solids or acid content. Subjective ratings of appearance and disorder incidence were unacceptable for pears stored in a variable atmosphere wrapped in dry or paper containing 3% oil. The disorder black speck was present only in pears wrapped in paper with 6% oil and stored in an atmosphere of 1.5% O2 and 1% CO2. Pears stored in an atmosphere of 1.5% O2 and 3% CO2 received acceptable subjective scores regardless of paper type.
- Published
- 2001
28. Effects of mixture of CO2 /CH4 as pyrolysis atmosphere on pine wood pyrolysis products
- Author
-
Xiufeng Shi, Alexander K. Goroncy, Asif Hasan Rony, Maohong Fan, Morris D. Argyle, Bang Xu, and Gang Tan
- Subjects
060102 archaeology ,Carbon dioxide reforming ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Fixed bed ,020209 energy ,06 humanities and the arts ,02 engineering and technology ,Pulp and paper industry ,Methane ,Atmosphere ,chemistry.chemical_compound ,Integrated technology ,Pine wood ,0202 electrical engineering, electronic engineering, information engineering ,0601 history and archaeology ,Phenols ,Pyrolysis - Abstract
The aim of the present work is to provide a preliminary support and research foundation for developing integrated technology of methane dry reforming and pine wood pyrolysis to produce high value chemicals and fuels. The chemical properties of bio-oil produced by pine wood pyrolysis under traditional N2, H2, CO2, CH4 atmospheres and mixtures of CH4 and CO2 were investigated. Experimental studies were conducted in a fixed bed reactor at a temperature of 500 °C. The results show that pine wood pyrolysis under mixtures of methane and CO2 can promote bio-oil production (0.98% increase) compared with traditional pyrolysis (under N2). GC-MS results show that the contents of phenols and sugars in bio-oil decreased, while the amount of alcohols, aldehydes, ketones, and furans increased. NMR spectroscopy provides additional support of the results. Results indicate that bio-oil can be used as a source of value-added chemicals. High proportions of CO were obtained in the gas products from pine wood pyrolysis under CH4 and mixtures of CH4 and CO2. Finally, a possible reaction pathway of pine wood pyrolysis under mixtures of methane and CO2 is proposed. Methane bi-reforming with CO2 and steam from pine wood pyrolysis could promote the production of high value oxygen-containing chemicals during pine wood pyrolysis under mixtures of CH4 and CO2.
- Published
- 2020
29. The Behaviour of Paper Treated in a Carbon Dioxide Modified Atmosphere
- Author
-
Svetlana A. Dobrusina and Valeria I. Kobiakova
- Subjects
Carbonic acid ,Chemistry ,Air pollution ,Environmental engineering ,Humidity ,chemistry.chemical_element ,Conservation ,medicine.disease_cause ,Pulp and paper industry ,Atmosphere ,chemistry.chemical_compound ,Modified atmosphere ,Carbon dioxide ,Media Technology ,medicine ,General Materials Science ,Relative humidity ,Carbon - Abstract
The treatment of museum exhibits, including books and archival documents, in an atmoshpere containing a high concentration of carbon dioxide is one of the techniques using a modified atmosphere for the fumigation of objects. The efficiency of this method for pest infestation is confirmed by its commercial application. Some companies (for example, RENTOKIL) have developed stationary and portable extermination equipment. The concentration of the carbon dioxide in a gas mixture is between 58-75 per cent, the temperature during the disinfecting procedure is kept within 19-30 degrees C, and the relative humidity is kept to 70 per cent. The efficiency of this prodecure as an effective technique against microorgnisms has not been studied fully. There is evidence of both positive and negative results. Specific data on the influence of a carbon dioxide enriched atmosphere on the physical and chemical properties is limited. In theory this treatment could be dangerous for paper because of the formation of carbonic acid from carbon dioxide and water. In order to decrease the possible destructive influence of this treatment used on textile museum objects, humidity in a chamber has been kept at no more than 50 per cent. According to the data of the German conservator Binker the fumigation of a wooden altarpiece in an atmosphere of carbon dioxide did not have any adverse affect on the material or colouring of the wooden sculpture. The purpose of our research was to investigate the influence of a modified, carbon dioxide-enriched atmosphere on the properties of paper.
- Published
- 2003
30. Oxygen signaling: Call for papers
- Author
-
Roger G. Evans
- Subjects
Atmosphere ,03 medical and health sciences ,0302 clinical medicine ,chemistry ,Physiology ,Ecology ,Physiology (medical) ,chemistry.chemical_element ,Earth (chemistry) ,030204 cardiovascular system & hematology ,030224 pathology ,Oxygen ,Astrobiology - Abstract
it has recently been estimated that appreciable concentrations of oxygen in the Earth’s atmosphere and oceans have only been present for the last ~10% of its ~4.5 billion year life ([4][1]). There is also increasing evidence for a “bumpy road” to atmospheric oxygenation, starting with “
- Published
- 2016
31. EXTERNAL PIXE ANALYSIS OF OLD INKS AND PAPERS
- Author
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M. Lamehi-Rachti, F. Shokouhi, Javad Rahighi, Abdollah Hassanzadeh, and P. Oliaiy
- Subjects
Atmosphere ,Materials science ,Optics ,Material analysis ,law ,business.industry ,Van de Graaff generator ,Mineralogy ,business ,law.invention - Abstract
Proton Induced X-ray Emission, PIXE is a very well established analytical method. This technique of analysis can equally be applied both in vacuum, internal PIXE, and in atmosphere, external PIXE. External PIXE has been applied to material analysis in Van de Graaff laboratory at AEOI using filters and funny filters. Advantages of using these filters have been studied when analysing ancient written documents such as envelopes, inks, and newspapers. This technique clearly demonstrated the differences between new and old inks and papers. More data is needed to show other features of this technique.
- Published
- 1999
32. Atmospheric deposits of dissolved inorganic nitrogen in the southwest of France 1This paper is a DGO, UMR-CNRS 5805 contribution, n° 1275. 1
- Author
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E. Maneux, Peggy Rimmelin, Didier Burdloff, and Jean-Claude Dumon
- Subjects
Hydrology ,Environmental Engineering ,Flux ,Storm ,Seasonality ,medicine.disease ,Pollution ,Atmosphere ,chemistry.chemical_compound ,Nitrate ,chemistry ,medicine ,Environmental Chemistry ,Environmental science ,Ecosystem ,Ammonium ,Eutrophication ,Waste Management and Disposal - Abstract
A 1-year study of bulk atmospheric dissolved inorganic nitrogen (DIN) deposits has identified a medium anthropogenic impact in the southwest of France (average NO3 concentration=26.2 μM; yearly NO3 flux=22.6±5 mmol/m2 per year; average NH4 concentration=17.8 μM; yearly NH4 flux=14.6±3 mmol/m2 per year). The air flow directions have shown that the contamination is derived from Spain and the south of France during the winter period and from northern Europe in the summer period. However, long range transport of ammonia is less probable because of its short residence time in the atmosphere due to its high solubility. Moreover, a seasonal variation has affected ammonium (2.4 times higher in the cultivation period), while nitrate remained statistically constant. Although no difference of ammonium concentration was observed under the influence of oceanic and continental winds, it must be influenced by regional emissions from agricultural areas. In the summer period, the atmospheric source makes up 26% of the total DIN inputs into the Arcachon Lagoon. Moreover, an exceptional storm event represented 96% of the total input in a single day. Thus, such a seasonal pattern suggests an important impact of atmospheric DIN deposits on primary production in coastal ecosystems of such a region less industrialized since they often show oligotrophic conditions in the summer period.
- Published
- 1999
33. PENGEMASAN BUAH DAN SAYUR DENGAN ATMOSFIR TERMODIFIKASI
- Author
-
Erika Pardede
- Subjects
Food industry ,business.industry ,chemistry.chemical_element ,Pulp and paper industry ,Shelf life ,Oxygen ,Atmosphere ,chemistry ,Modified atmosphere ,Respiration ,Environmental science ,Respiration rate ,business ,Oxygen scavenger - Abstract
Being living organs, fresh harvested fruits and vegetables remain metabolically active and undergo ripening and senescence processes. They needs oxygen to stay alive, which is vital for energy production through respiration process. Modified Atmosphere Packaging (MAP) technology utilises in-packaging equilibrium atmosphere, in which the relatively low oxygen and high carbondioxide concentration is achieved naturally inside the package as respiration occurs, which later on leads to a lower respiration rate. Low oxygen concentration could also be achieved by replacing some oxygen with nitrogen and/or application of oxygen scavenger inside in package, thus the respiration rate is reduced and the aging process is retarded. The use of packaging films of correct intermediary permiability to meet a desirable equilibrium modified atmosphere become a key to the succes of MAP. A new technique, so called Perforation-Mediated Modified Atmosphere Packaging (PM-MAP), by having microperforation in the plastic films is applied to correct the exchange of air during storage. Therefore Modified Atmosphere Packaging (MAP) technology offers advantages which leads to extension of the shelf life of fresh produces. Fresh and fresh-cut food industry utilise this advantages to meet the growing demand of convinient and fresh quality fruits and vegetables, in order to maintain freshness quality attributes and to extend the shelf life.
- Published
- 2020
34. Magnetic circular dichroism in Archean atmosphere and asymmetric photolysis of biomolecules: enantiomeric excess of prebiotic sugar
- Author
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A. Sharma
- Subjects
0301 basic medicine ,Biophysics ,Analytical chemistry ,Glyceraldehyde ,01 natural sciences ,Autocatalysis ,03 medical and health sciences ,Paramagnetism ,0103 physical sciences ,Enantiomeric excess ,Molecular Biology ,Circular polarization ,Original Paper ,Quantitative Biology::Biomolecules ,Photolysis ,010304 chemical physics ,Atmosphere ,Chemistry ,Magnetic circular dichroism ,Circular Dichroism ,Magnetic Phenomena ,Mathematics::History and Overview ,Photodissociation ,Stereoisomerism ,Cell Biology ,Atomic and Molecular Physics, and Optics ,030104 developmental biology ,Anisotropy ,Astrophysics::Earth and Planetary Astrophysics ,Enantiomer ,Homochirality - Abstract
In the terrestrial dipolar magnetic field, magnetic circular dichroism (MCD) of UV sunlight by paramagnetic O(2) in an Archean atmosphere (mostly CO(2) and N(2)) results in circular polarization anisotropy (~ 10(−10)). This is used to calculate enantiomeric excess (EE~10(−13)) of glyceraldehyde (3-carbon sugar) with a model that includes racemic production and asymmetric photolysis of its enantiomers. The sign and magnitude of enantiomeric excess (EE) vary with the Earth’s latitude. Unlike random noise fluctuation in spontaneous mirror symmetry breaking (SMSB) models, the sign of EE is deterministic and constant over large areas of prebiotic Earth. The magnitude is several orders greater than the mean amplitude of stochastically fluctuating EE. MCD could provide the initial EE for growth of homochirality by asymmetric autocatalysis.
- Published
- 2020
35. The effect of different atmosphere absolute hyperbaric oxygen on the expression of extracellular histones after traumatic brain injury in rats
- Author
-
Ding Nan, Jing Yang, Wan-Qiu Zhu, Fang Liang, Lei Sun, Jing Zhang, Lu Yang, and Xuehua Liu
- Subjects
Male ,medicine.medical_specialty ,Traumatic brain injury ,Apoptosis ,Biochemistry ,Lesion ,Histones ,Rats, Sprague-Dawley ,Hyperbaric oxygen ,Western blot ,Internal medicine ,Brain Injuries, Traumatic ,medicine ,Extracellular ,Extracellular histones ,Animals ,RNA, Messenger ,Original Paper ,Hyperbaric Oxygenation ,TUNEL assay ,biology ,medicine.diagnostic_test ,business.industry ,Atmosphere ,Transcription Factor RelA ,Brain ,Cell Biology ,medicine.disease ,Disease Models, Animal ,Histone ,Endocrinology ,Gene Expression Regulation ,biology.protein ,Immunohistochemistry ,Cytokines ,Female ,medicine.symptom ,business ,Extracellular Space - Abstract
By observing the dynamic changes of extracellular histones H1, H2A, H4, and NF-κB expression in brain tissues after brain injury in rats, we explore the association among the expression of extracellular histones H1, H2A, H4, and NF-κB following traumatic brain injury (TBI), as well as the effect of different atmospheres absolute hyperbaric oxygen (HBO) intervention on the expression and possible mechanisms. A total of 120 SD rats were randomly divided into 4 groups: Sham-operated (SH), TBI (traumatic brain injury) group, traumatic brain injury and hyperbaric oxygen treatment 1.6ATA (TBI + HBO1) group, and traumatic brain injury and hyperbaric oxygen treatment2.2ATA (TBI + HBO2) group, with 30 rats in each group. The rats in each group were then randomly divided into five smaller time-specific sub-groups: 3 h, 6 h, 12 h, 24 h, and 48 h after surgery. TBI models were established, and the brain tissue around the lesion was taken at different time points. On the one hand,we detected the level of local histones H1, H2A, H4, and NF-κB by RT-PCR and Western Blot. On the other hand, we used immunohistochemical methods to detect the expression of NF-κB, while using the TUNEL method to observe the cell apoptosis in experimental groups after brain injury. Extracellular histones H1, H2A, H4, and NF-κB proteins were highly expressed at 3 h, then with a slight fluctuation, reached to peak at 48 h after the injury. HBO can affect the expression of histones H1, H2A, H4, and NF-κB. The decline of each indicator in the 1.6ATA group was significantly lower than that in the 2.2ATA group, especially within 6 h (P
- Published
- 2020
36. Combustion of single particles from sewage sludge/pine sawdust and sewage sludge/bituminous coal under oxy-fuel conditions with steam addition
- Author
-
Dong Liu, Rui Zhang, Buqing Ye, Jin Cao, and Kai Lei
- Subjects
Materials science ,020209 energy ,geology ,02 engineering and technology ,010501 environmental sciences ,Combustion ,01 natural sciences ,law.invention ,Bioenergy ,law ,0202 electrical engineering, electronic engineering, information engineering ,Coal ,Gas composition ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Bituminous coal ,Sewage ,Atmosphere ,business.industry ,geology.rock_type ,Boiler (power generation) ,Pinus ,Pulp and paper industry ,Ignition system ,Steam ,visual_art ,visual_art.visual_art_medium ,Sawdust ,business - Abstract
Co-pelletization of sewage sludge (SS) and conventional fuels for combustion is considered to be a feasible SS disposal method. Oxy-fuel combustion is recognized as a promising technology to reduce the emission of CO2. In practical applications, the combustion atmosphere in oxy-fuel boiler is O2/CO2/H2O, which is different from that in the conventional boiler (O2/N2). Therefore, the effects of gas composition on the combustion characteristics of boiler fuels should be both taken into consideration. In this work, the SS/pine sawdust (PS) and SS/bituminous coal (BC) blended fuel particles were prepared, and the single particle combustion experiments were conducted in O2/N2, O2/CO2 and O2/CO2/H2O atmospheres. The influences of SS blending proportion and gas composition on combustion characteristics of fuel particles were analyzed. The results reveal that increasing the blending proportion of SS from 20 to 40 wt% decreases the ignition delay time, burnout time and combustion temperature. The substitution of N2 by CO2 increases the ignition delay time and burnout time, while decreases the combustion temperature. Replacing CO2 by 10 vol%, 20 vol% and 30 vol% H2O decreases the ignition delay time and burnout time, while increases the combustion temperature.
- Published
- 2020
37. Study on thermal decomposition kinetics model of sewage sludge and wheat based on multi distributed activation energy
- Author
-
Yanfen Liao, Xiaoqian Ma, Junnan Wu, Yan Lin, and Yunlong Tian
- Subjects
Thermogravimetric analysis ,Chemistry ,020209 energy ,Mechanical Engineering ,Thermal decomposition ,02 engineering and technology ,Building and Construction ,Straw ,Pulp and paper industry ,Pollution ,Industrial and Manufacturing Engineering ,Atmosphere ,General Energy ,020401 chemical engineering ,Biochar ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,Electrical and Electronic Engineering ,Thermal analysis ,Pyrolysis ,Sludge ,Civil and Structural Engineering - Abstract
The pyrolysis characteristics of sewage sludge, wheat straw and its mixture were studied by non-isotropic thermogravimetric analysis (TGA). In the temperature range of 400 K–950 K, 40 K/min, 45 K/min and 50 K/min heating rate were set respectively, in N2 atmosphere and CO2/N2 mixed atmosphere. According to the thermal analysis chart obtained from TGA, it was observed the vast majority of mass loss spread at the range of 450–800 K in all samples. The Co-pyrolysis kinetics of sewage sludge and wheat straw was described by a fourth-order DAEM model. It is proved that the model can well match the TG experimental data. The results obtained from the optimized parameters show that the activation of sewage sludge is lower than that of wheat straw, and the activity of the mixture gradually increased with the increase of wheat straw content. The presence of CO2 has a slight inhibitory effect on the pyrolysis of the mixture below 900 K compared to that in an N2 atmosphere, but with temperature increasing, CO2 will have a secondary reaction with biochar.
- Published
- 2019
38. A Review on the Modified Atmosphere Preservation of Fruits and Vegetables with Cutting-Edge Technologies
- Author
-
Minato Wakisaka and Yujie Fang
- Subjects
Agriculture (General) ,Food spoilage ,Active packaging ,Plasma treatment ,fruits and vegetables ,Plant Science ,Shelf life ,Pulp and paper industry ,S1-972 ,Atmosphere ,food loss ,Fruits and vegetables ,Modified atmosphere ,Postharvest ,Environmental science ,shelf life ,Agronomy and Crop Science ,atmosphere storage technology ,Food Science - Abstract
Respiration and microbial infection are important causes of postharvest spoilage of fruits and vegetables (F&V). Atmosphere storage technology can significantly reduce postharvest losses. This comprehensive review aims to cover recent progress in the application of atmosphere storage to F&V preservation, not only focusing on the effect of gas conditions but also evaluating combination applications involving newer preservation technologies, including ethylene scavengers, high-pressure and decompression technology, ozone, ultraviolet radiation, active packaging, high-voltage electrostatic field, plasma treatment, and pulse-controlled atmosphere. Appropriate choice of storage conditions optimal for each F&V is essential since the physiological properties and sensory qualities are affected by them. The combination of atmosphere storage with these emerging technologies could contribute to significant reductions in food loss during storage.
- Published
- 2021
39. Opinion paper. Primary responses of root and leaf elongation to water deficits in the atmosphere and soil solution
- Author
-
J Frensch
- Subjects
Atmosphere ,Agronomy ,Physiology ,Environmental science ,Soil solution ,Plant Science ,Elongation - Published
- 1997
40. Elliptical pollen corona from North American boreal paper birch trees (Betula papyrifera): strong fall orientations for near-spherical particles
- Author
-
Kenneth Sassen
- Subjects
Meteorology ,Light ,Optical Phenomena ,Materials Science (miscellaneous) ,medicine.disease_cause ,Atmospheric sciences ,Industrial and Manufacturing Engineering ,Atmosphere ,Optics ,Pollen ,medicine ,Photography ,Scattering, Radiation ,Business and International Management ,Particle Size ,Betula ,business.industry ,Reproduction ,Elevation ,Radius ,Corona ,Boreal ,Particle ,Seasons ,business ,Geology ,Atmospheric optics ,Alaska - Abstract
It has only recently been realized that solar corona can be generated by dispersions of tree pollen grains suspended in the atmosphere, and these studies have come almost exclusively from Scandinavia. Using corona photographic and surface pollen analyses, it is shown here that paper birch trees in the interior of Alaska regularly generate solar corona during the boreal green-out in mid-May. Although near-spherical in shape, these ∼27 μm average diameter particles have three surface protrusions involved in germination that are indicated to aid in the generation of elliptical corona, for which a strong preferential particle orientation is needed. For observations at solar elevation angles of ∼35°–40°, an axis ratio of about 1.2 and average radius of 2.5° (for the second-order red band) are found. Because oriented particles of a particular shape tend to fall slower than randomly oriented ones, this microdesign promotes the lateral spread of pollen and enhances tree reproductive opportunities, an especially important trait for pioneering species.
- Published
- 2011
41. The Ensemble Mars Atmosphere Reanalysis System (EMARS) Version 1.0
- Author
-
Thomas Nehrkorn, Patrick M. Dudas, Steven J. Greybush, Takemasa Miyoshi, R. John Wilson, Mark Leidner, Timothy H. McConnochie, M. Wespetal, Janusz Eluszkiewicz, Armin Kleinböhl, Ross N. Hoffman, Matthew J. Hoffman, Yongjing Zhao, David M. Kass, Daniel J. McCleese, H. E. Gillespie, and Eugenia Kalnay
- Subjects
Data Papers ,Thermal Emission Spectrometer ,Meteorology ,reanalysis ,Physics::Geophysics ,Atmosphere ,Data assimilation ,Polar vortex ,Meteorology. Climatology ,Thermal ,mars ,Physics::Atmospheric and Oceanic Physics ,QE1-996.5 ,assimilation ,ensemble ,Storm ,Geology ,Mars Exploration Program ,Atmosphere of Mars ,Physics::Space Physics ,atmosphere ,General Earth and Planetary Sciences ,Environmental science ,Astrophysics::Earth and Planetary Astrophysics ,QC851-999 ,Data Paper - Abstract
The Ensemble Mars Atmosphere Reanalysis System (EMARS) dataset version 1.0 contains hourly gridded atmospheric variables for the planet Mars, spanning Mars Year (MY) 24 through 33 (1999 through 2017). A reanalysis represents the best estimate of the state of the atmosphere by combining observations that are sparse in space and time with a dynamical model and weighting them by their uncertainties. EMARS uses the Local Ensemble Transform Kalman Filter (LETKF) for data assimilation with the GFDL/NASA Mars Global Climate Model (MGCM). Observations that are assimilated include the Thermal Emission Spectrometer (TES) and Mars Climate Sounder (MCS) temperature retrievals. The dataset includes gridded fields of temperature, wind, surface pressure, as well as dust, water ice, CO2 surface ice and other atmospheric quantities. Reanalyses are useful for both science and engineering studies, including investigations of transient eddies, the polar vortex, thermal tides and dust storms, and during spacecraft operations.
- Published
- 2019
42. Variation and dispersal of PM10 and PM2.5 during COVID-19 lockdown over Kolkata metropolitan city, India investigated through HYSPLIT model
- Author
-
Sumana Bhattacharjee, Soumik Saha, Biswajit Bera, and Nairita Sengupta
- Subjects
QE1-996.5 ,COVID-19 ,Geology ,Weather and climate ,Variation ,Dispersal ,Particulates ,Metropolitan area ,Wind speed ,Atmosphere ,Climatology ,Lockdown ,HYSPLIT ,General Earth and Planetary Sciences ,Environmental science ,Relative humidity ,Visibility ,HYSPLIT model ,ComputingMethodologies_COMPUTERGRAPHICS ,Research Paper - Abstract
Graphical abstract, The higher concentration of PM10 and PM2.5 in the lower atmosphere is severely harmful for human health and it also makes visibility diminution along with weather and climate modifications. The main objective is to find out the spatiotemporal variation and dispersal of PM10 and PM2.5 along with COVID-19 infection in the dusty city Kolkata. The consecutive two years PM10 and PM2.5 data of different stations have been obtained from State Pollution Control Board, Govt. of West Bengal. Forward trajectory analysis has been done through HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model to find the path and direction of air particles. The result showed that the various meteorological or environmental factors (such as temperature, relative humidity, wind, wind speed, pressure and gusty wind) and geographical location regulate the spatiotemporal variation of PM10 and PM2.5. These factors like high temperature with relative humidity and strong wind influence to disperse the particulate matters from north to south direction from city to outside during summer in Kolkata metropolitan city. During summer (both pre and lockdown years), the height of particles is extended up to 1000 m owing to active atmospheric ventilation whereas in winter it is confined within 100 m. The HYSPLIT model clearly specified that the particles dispersed from south, south-west to north and north east direction due to strong wind. The constant magnification of PM10 and PM2.5 in the lower atmosphere leads to greater frequency of COVID-19 infections and deaths. In Kolkata, the one of the crucial reasons of high infection and deaths (COVID-19) is co-morbidity of people.
- Published
- 2021
43. Airborne black carbon variations during the COVID-19 lockdown in the Yangtze River Delta megacities suggest actions to curb global warming
- Author
-
Qian Tang, Hao Li, Xudong Tian, Zhen Wei, Qingyan Fu, Congrui Deng, Yanfen Lin, Kan Huang, Qingchuan Song, and Jia Chen
- Subjects
Delta ,Original Paper ,business.industry ,Global warming ,Fossil fuel ,COVID-19 ,Carbon black ,Particulates ,Combustion ,Atmosphere ,Black carbon ,Megacity ,Environmental protection ,Lockdown ,Environmental Chemistry ,Environmental science ,business ,Spatial correlation ,Yangtze River Delta - Abstract
Airborne black carbon is a strong warming component of the atmosphere. Therefore, curbing black carbon emissions should slow down global warming. The 2019 coronavirus pandemic (COVID-19) is a unique opportunity for studying the response of black carbon to the varied human activities, in particular due to lockdown policies. Actually, there is few knowledge on the variations of black carbon in China during lockdowns. Here, we studied the concentrations of particulate matter (PM2.5) and black carbon before, during, and after the lockdown in nine sites of the Yangtze River Delta in Eastern China. Results show 40-60% reduction of PM2.5 and 40-50% reduction of black carbon during the lockdown. The classical bimodal peaks of black carbon in the morning and evening rush hours were highly weakened, indicating the substantial decrease of traffic activities. Contributions from fossil fuels combustion to black carbon decreased about 5-10% during the lockdown. Spatial correlation analysis indicated the clustering of the multi-site black carbon concentrations in the Yangtze River Delta during the lockdown. Overall, control of emissions from traffic and industrial activities should be efficient to curb black carbon levels in the frame of a 'green public transit system' for mega-city clusters such as the Yangtze River Delta. Supplementary information The online version contains supplementary material available at 10.1007/s10311-021-01327-3.
- Published
- 2021
44. Oxy-steam combustion: The effect of coal rank and steam concentration on combustion characteristics
- Author
-
Luis I. Díez, María P. Aznar, and Ana Escudero
- Subjects
020209 energy ,General Chemical Engineering ,geology ,Energy Engineering and Power Technology ,Coal combustion products ,02 engineering and technology ,Combustion ,complex mixtures ,Degree (temperature) ,law.invention ,Atmosphere ,020401 chemical engineering ,law ,0202 electrical engineering, electronic engineering, information engineering ,Coal ,0204 chemical engineering ,Bituminous coal ,business.industry ,Organic Chemistry ,geology.rock_type ,Autoignition temperature ,respiratory system ,Pulp and paper industry ,Ignition system ,Fuel Technology ,Environmental science ,business - Abstract
This paper addresses the experimental investigation of coal combustion characteristics (ignition, burnout and NO formation) under oxy-steam combustion conditions. Two coals are selected in order to compare the effect of the rank: bituminous and sub-bituminous ones. The experiments have been conducted in an electrically-heated entrained flow reactor for a set of O2/N2, O2/CO2 and O2/H2O/CO2 atmospheres, with O2 concentrations up to 35% and H2O concentrations up to 40%. Regarding ignition, 10% H2O reduces ignition temperature (max. 16–19 K) but the trend is reversed when supplying additional steam to 25% and 40%. This behaviour is similar for both coals, with slight larger variations in the case of the low rank coal. Burnout degree of the sub-bituminous coal is barely affected by the steam concentration since all observed conversions are very high. Larger increments (up to 6.1 percentage points) are obtained for the bituminous coal, with a maximum burnout degree for the 25/35% H2O/O2 atmosphere. A very different effect of steam on NO formation is found depending on the coal rank. Significant reduction rates are observed for the bituminous coal in comparison to the dry O2/CO2 atmospheres, with a maximum diminution of 24% when 40% H2O replaces CO2. On the contrary, the higher volatile content in the sub-bituminous coal leads to NO increments up to 9%. For all the combustion characteristics studied, the increase of O2 concentrations attenuates the effects caused by the steam addition.
- Published
- 2021
45. GLAZBA ERICHA ZANNA
- Author
-
Vondrak, Luka and Pavlović, Nenad
- Subjects
puppetry ,UMJETNIČKO PODRUČJE. Kazališna umjetnost (scenske i medijske umjetnosti). Lutkarstvo ,paper ,atmosphere ,lutkarstvo ,gluma ,papir ,atmosfera ,FIELD OF ART. Theater Arts (Performing and Media Arts). Puppetry ,acting - Abstract
Glazba Ericha Zanna diplomska je predstava iz lutkarstva studenta Luke Vondraka. Predstava je ujedno i ispit iz lutkarske režije studentice Tončice Knez, te također ispit iz lutkarstva studentima Vedranu Dakiću i Moniki Lanšćak. Mentorstvo potpisuje doc. art. Nenad Pavlović. U ovom radu student opisuje značenje lutkarstva na osobnoj razini, redateljski koncept, proces rada na predstavi uz analizu vlastite izvedbe. Student zaključuje da mu je ovaj rad bio od velike važnosti kao utemeljenje i afirmacija dosadašnjeg školovanja. The Music of Erich Zann is a puppetry graduate play by student Luka Vondrak. The play is also an exam in puppet directing for student Tončica Knez, and also an exam in puppetry for students Vedran Dakić and Monika Lanšćak. Mentorship is signed by doc. art. Nenad Pavlović. In this paper the student describes the meaning of puppetry on a personal level, the directorial concept, the process of working on the play alongside an analysis of his performance. The student concludes that this work was of great importance to him as a revision and an affirmation of his schooling.
- Published
- 2021
46. Determining the collection efficiency of gummed paper for the deposition of radioactive contaminants in simulated rain
- Author
-
M.L. Frank, K.M. Thiessen, F.O. Hoffman, and B. G. Blaylock
- Subjects
Pollution ,Paper ,Radioactive Fallout ,Epidemiology ,Health, Toxicology and Mutagenesis ,Radioactive fallout ,media_common.quotation_subject ,Rain ,Radioactive waste ,Contamination ,Atmosphere ,Deposition (aerosol physics) ,Environmental chemistry ,Adhesives ,Environmental science ,Radiology, Nuclear Medicine and imaging ,Saturation (chemistry) ,Surface runoff ,media_common - Abstract
An extensive network of gummed paper collectors was used during the 1950s for routine monitoring of radioactive fallout from weapons testing. The experiments reported in this paper were designed to examine the collection efficiency of gummed paper for wet deposition of several types of soluble and insoluble radioactive contaminants under conditions similar to those found during natural rainstorms. The collection efficiencies for each substance were determined over a range of rainfall amounts and at two separate rainfall intensities. The collection efficiency of the gummed paper is highest for large insoluble particles and lowest for soluble ionic substances. The values for 7Be and 131I ranged from about 0.30 (30%) at 2.5 mm of rain to 0.04-0.06 (4%-6%) at 20 mm of rain. These values were negatively correlated with the amount of rain and were unaffected by rain intensity. This suggests that the collection efficiency of either ion is simply a matter of rapid saturation and runoff. Neither rain amount nor rain intensity has much effect on the collection efficiency of large insoluble particles. These particles seem to settle readily onto the surface of the gummed paper from which they are not easily removed by additional rain. Analysis of the collection efficiencies of the gummed paper included the activity of both the gummed paper and the standing water on the paper. A large portion of the activity for the ionic substances was found in the standing water. There was less activity by insoluble particles in standing water. This indicates that for estimates of deposition of soluble substances, considerable bias could be introduced into the results if the standing water is discarded prior to analysis.
- Published
- 1992
47. FAST CORRECTION OF ATMOSPHERIC TURBULENCE USING A MEMBRANE DEFORMABLE MIRROR – Poster Paper
- Author
-
Stefano Bonora, Ivan Capraro, and Paolo Villoresi
- Subjects
Physics ,Atmosphere ,Optics ,Tilt (optics) ,Quantum cryptography ,business.industry ,Atmospheric turbulence ,business ,Deformable mirror - Published
- 2008
48. Efficient production of high calorific value solid fuel from palm oil empty fruit bunch by pressurized hydrothermal carbonization
- Author
-
Mi Yan, Zhouchao Weng, Muhammad Danang Birowosuto, Roy Hendroko Setyobudi, and Bayu Prabowo
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Carbonization ,020209 energy ,Energy Engineering and Power Technology ,02 engineering and technology ,Pulp and paper industry ,Solid fuel ,Atmosphere ,Hydrothermal carbonization ,020401 chemical engineering ,Pressure increase ,0202 electrical engineering, electronic engineering, information engineering ,Palm oil ,Production (economics) ,Heat of combustion ,0204 chemical engineering - Abstract
The efficient production of high calorific value solid fuel from palm oil empty fruit bunch (EFB) was investigated by experimenting hydrothermal carbonization (HTC) with initial absolute pressures of 0.1 MPa, 1.3 MPa, and 3.1 MPa in N2 atmosphere and in CO2 atmosphere. The pressure increase in HTC is expected to promote the improvement of calorific value in efficient way, while the alteration of reaction atmosphere from N2 to CO2 is aimed at obtaining higher extent of carbonization. Increasing the initial pressure of N2 improved calorific value of the derived fuel from 19.3 MJ/kg to 22.2 MJ/kg, while creating only trivial effect on energy yield. Increasing the initial pressure of CO2 further enhanced the carbonization and resulted in fuel with maximum calorific value of 23.6 MJ/kg. However, it also resulted in up to 6% reduction on energy yield compared with the cases with N2. The advantages of pressurized HTC in N2 atmosphere and in CO2 atmosphere over conventional HTC were evident when used for the production of fuels with comparable heating value. Process efficiencies of the pressurized HTC in both N2 and CO2 atmospheres were shown to be 4–8% higher than those of conventional HTC with normal initial reaction pressure.
- Published
- 2019
49. Co-pyrolysis of bituminous coal and biomass in a pressured fluidized bed
- Author
-
Huang Yong, Ningbo Wang, Liu Qiaoxia, Wang Wusheng, and Xiaoxun Ma
- Subjects
Bituminous coal ,Environmental Engineering ,General Chemical Engineering ,geology.rock_type ,geology ,Tar ,Biomass ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Biochemistry ,Product distribution ,Atmosphere ,020401 chemical engineering ,Fluidized bed ,Environmental science ,Char ,0204 chemical engineering ,0210 nano-technology ,Pyrolysis - Abstract
An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor. The blend ratio of biomass in the mixture was varied between 0 and 100 wt%, and the temperature was over a range of 550–650 °C under 1.0 MPa pressure with different atmospheres. On the basis of the individual pyrolysis behavior of bituminous coal and biomass, the influences of the biomass blending ratio, temperature, pressure and atmosphere on the product distribution were investigated. The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor, especially when the condition of bituminous coal and biomass blend ratio of 70:30 (w/w), 600 °C, and 0.3 MPa was applied. The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis. The tar yields were higher than the calculated values from individual pyrolysis of each fuel, and consequently the char yields were lower. The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel. The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.
- Published
- 2019
50. Environmental impact of combustion of ethanolic biodiesel/diesel blends from several feedstocks on the gas emission levels in the atmosphere
- Author
-
Euripedes Garcia Silveira Junior, Marcelo Gomes da Silva, Victor Haber Perez, Torquato F. Pinheiro, Marcelo Silva Sthel, and Maria Priscila Pessanha de Castro
- Subjects
Air Pollutants ,Biodiesel ,Esterification ,Ethanol ,Atmosphere ,Health, Toxicology and Mutagenesis ,General Medicine ,Transesterification ,010501 environmental sciences ,Raw material ,Combustion ,Pulp and paper industry ,01 natural sciences ,Pollution ,Greenhouse Gases ,Diesel fuel ,Biofuel ,Biofuels ,Biodiesel production ,Environmental Chemistry ,Environmental science ,NOx ,Environmental Monitoring ,Vehicle Emissions ,0105 earth and related environmental sciences - Abstract
The aim of this work was to evaluate simultaneously the effect of produced ethanolic biodiesel from several feedstocks (soybean, crambe, macaw, sunflower, and waste cooking oil) and engine operational conditions (low and high engine speed) during combustion of biodiesel/diesel blends on the N2O, NOx, NO, CO2, and CO emission levels in the atmosphere. The biodiesel samples were prepared in one and/or two reaction steps, according to the acid index of each raw material, by esterification using H2SO4 and/or chemical transesterification using sodium ethoxide, both, through ethanolic route. The quality of the produced biodiesels was confirmed by ASTM/EN specifications. Then, biodiesel/diesel blends were prepared according to the following proportions: 10% (B10), 15% (B15), 25% (B25), and 50% (B50). In general way, all raw materials under combustion at low and high engine speed contributed to the formation of NOx and this effect was more drastically increased as the biodiesel concentration in the blends increases. N2O presented a similar behavior except for blends containing crambe and macaw biodiesel whose emissions were slightly reduced as a function of biodiesel content in these blends. Then, Principal component analysis (PCA) was applied to discriminate the effect of engine operating conditions, biodiesel kind, and biodiesel content in the blends during their combustion on the exhaust emissions. The attained results point to crambe and macaw as more environmentally sustainable feedstocks for biodiesel production because they generate less greenhouse gas emissions. These results are particularly attractive considering that, both, crambe and macaw are non-edible feedstocks with great potential for biodiesel production.
- Published
- 2019
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