scholarly journals Chemical Composition and Sources Estimation of PM2.5 and Submicron Particles (PM1) in Urban Atmosphere Based on Chemical Components

2018 ◽  
Vol 67 (6) ◽  
pp. 363-368
Author(s):  
Tomoya KONISHI ◽  
Shinichi YONEMOCHI ◽  
Masaru MURATA
Keyword(s):  
Chemical Composition ◽  
Urban Atmosphere ◽  
Submicron Particles ◽  
Chemical Components

scholarly journals Atmospheric chemistry and physics in the atmosphere of a developed megacity (London): an overview of the REPARTEE experiment and its conclusions

2012 ◽  
Vol 12 (6) ◽  
pp. 3065-3114 ◽  
Author(s):  
R. M. Harrison ◽  
M. Dall'Osto ◽  
D. C. S. Beddows ◽  
A. J. Thorpe ◽  
W. J. Bloss ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Urban Atmosphere ◽  
Trace Gas ◽  
Chemical Components ◽  
Chemical Transformations ◽  
Specific Chemical ◽  
Gas Dispersion ◽  
Wide Range

Abstract. The REgents PARk and Tower Environmental Experiment (REPARTEE) comprised two campaigns in London in October 2006 and October/November 2007. The experiment design involved measurements at a heavily trafficked roadside site, two urban background sites and an elevated site at 160–190 m above ground on the BT Tower, supplemented in the second campaign by Doppler lidar measurements of atmospheric vertical structure. A wide range of measurements of airborne particle physical metrics and chemical composition were made as well as measurements of a considerable range of gas phase species and the fluxes of both particulate and gas phase substances. Significant findings include (a) demonstration of the evaporation of traffic-generated nanoparticles during both horizontal and vertical atmospheric transport; (b) generation of a large base of information on the fluxes of nanoparticles, accumulation mode particles and specific chemical components of the aerosol and a range of gas phase species, as well as the elucidation of key processes and comparison with emissions inventories; (c) quantification of vertical gradients in selected aerosol and trace gas species which has demonstrated the important role of regional transport in influencing concentrations of sulphate, nitrate and secondary organic compounds within the atmosphere of London; (d) generation of new data on the atmospheric structure and turbulence above London, including the estimation of mixed layer depths; (e) provision of new data on trace gas dispersion in the urban atmosphere through the release of purposeful tracers; (f) the determination of spatial differences in aerosol particle size distributions and their interpretation in terms of sources and physico-chemical transformations; (g) studies of the nocturnal oxidation of nitrogen oxides and of the diurnal behaviour of nitrate aerosol in the urban atmosphere, and (h) new information on the chemical composition and source apportionment of particulate matter size fractions in the atmosphere of London derived both from bulk chemical analysis and aerosol mass spectrometry with two instrument types.

scholarly journals Atmospheric chemistry and physics in the atmosphere of a developed megacity (London): an overview of the REPARTEE experiment and its conclusions

2011 ◽  
Vol 11 (11) ◽  
pp. 30145-30271 ◽  
Author(s):  
R. M. Harrison ◽  
M. Dall'Osto ◽  
D. C. S. Beddows ◽  
A. J. Thorpe ◽  
W. J. Bloss ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Urban Atmosphere ◽  
Trace Gas ◽  
Chemical Components ◽  
Chemical Transformations ◽  
Specific Chemical ◽  
Gas Dispersion ◽  
Wide Range

Abstract. The Regents Park and Tower Environmental Experiment (REPARTEE) comprised two campaigns in London in October 2006 and October/November 2007. The experiment design involved measurements at a heavily trafficked roadside site, two urban background sites and an elevated site at 160–190 m above ground on the BT Tower, supplemented in the second campaign by Doppler lidar measurements of atmospheric vertical structure. A wide range of measurements of airborne particle physical metrics and chemical composition were made as well as measurements of a considerable range of gas phase species and the fluxes of both particulate and gas phase substances. Significant findings include (a) demonstration of the evaporation of traffic-generated nanoparticles during both horizontal and vertical atmospheric transport; (b) generation of a large base of information on the fluxes of nanoparticles, accumulation mode particles and specific chemical components of the aerosol and a range of gas phase species, as well as the elucidation of key processes and comparison with emissions inventories; (c) quantification of vertical gradients in selected aerosol and trace gas species which has demonstrated the important role of regional transport in influencing concentrations of sulphate, nitrate and secondary organic compounds within the atmosphere of London; (d) generation of new data on the atmospheric structure and turbulence above London, including the estimation of mixed layer depths; (e) provision of new data on trace gas dispersion in the urban atmosphere through the release of purposeful tracers; (f) the determination of spatial differences in aerosol particle size distributions and their interpretation in terms of sources and physico-chemical transformations; (g) studies of the nocturnal oxidation of nitrogen oxides and of the diurnal behaviour of nitrate aerosol in the urban atmosphere, and (h) new information on the chemical composition and source apportionment of particulate matter size fractions in the atmosphere of London derived both from bulk chemical analysis and aerosol mass spectrometry with two instrument types.

scholarly journals The chemical composition of Lessonia berteroana (ex L. nigrescens) in kelp harvest management and open access areas near Coquimbo, Chile

2018 ◽  
Vol 46 (2) ◽  
pp. 258-267
Author(s):  
J.M. Alonso Vega ◽  
Pedro H. Toledo
Keyword(s):  
Resource Management ◽  
Chemical Composition ◽  
Open Access ◽  
Environmental Changes ◽  
Chemical Components ◽  
Optimal Harvesting ◽  
Harvest Management ◽  
Species Population ◽  
Pressure Indicators ◽  
Lessonia Berteroana

Lessonia berteroana (ex L. nigrescens) is kelp freely harvested from Open Access Areas (OAA), and to some extent controlled, from Management and Exploitation Areas for Benthic Resources (MEABR). Harvesting pressures can change population dynamics, mainly in OAAs. In particular, harvesting may alter the chemical components of plants. Therefore, the aim of this study was to determine the harvesting effects on the chemical composition of L. berteroana from MEABR and OAA sampled during different seasons (spring and fall) and at two sites (Talquilla and Lagunillas) near Coquimbo (30°S), Chile. The crude protein (13.5 ± 1.0%), total lipids (0.9 ± 0.2%), crude fiber (16.3 ± 1.6%), ash (30.1 ± 1.5%), and nitrogen-free extract (39.2 ± 2.0%) contents of L. berteroana were within reference values for Laminariales species. Population descriptors and chemical analyses showed that harvesting had local effects, rather than being affected by a resource management strategy (OAA vs MEABR). The seasonal anticipator nature of L. berteroana may explain the detected seasonality of it's chemical composition. Regarding functional morphological structures, chemical composition in the fronds was more variable than in the stipes and perennial holdfast, probably since leaves are ephemeral structures susceptible to environmental changes and that play a functional, rather than structural, role in kelp. In the context of Chilean kelp resource management, monitoring chemical composition is useful for determining optimal harvesting periods to local scale and for deciding when commercially valuable compounds, such as alginate, should be extracted. These data also complement harvesting pressure indicators based on L. berteroana demographic parameters.

scholarly journals Effects of rhizosphere fungi on the chemical composition of fruits of the medicinal plant Cinnamomum migao endemic to southwestern China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingzhong Chen ◽  
Xiaolong Huang ◽  
Bingli Tong ◽  
Deng Wang ◽  
Jiming Liu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fungal Community ◽  
Small Population ◽  
Biologically Active ◽  
Fungal Communities ◽  
Chemical Components ◽  
Rhizosphere Fungi ◽  
Medicinal Value ◽  
Main Driver ◽  
Fungal Populations

Abstract Background This study examined how rhizosphere fungi influence the accumulation of chemical components in fruits of a small population species of Cinnamomum migao. Results Ascomycota and Basidiomycota were dominant in the rhizosphere fungal community of C. migao. Pestalotiopsis and Gibellulopsis were associated with α-Terpineol and sabinene content, and Gibellulopsis was associated with crude fat and carbohydrate content. There were significant differences in rhizosphere fungal populations between watersheds, and there was no obvious change between fruiting periods. Gibberella, Ilyonectria, Micropsalliota, and Geminibasidium promoted sabinene accumulation, and Clitocybula promoted α-Terpineol accumulation. Conclusion The climate-related differentiation of rhizosphere fungal communities in watershed areas is the main driver of the chemical composition of C. migao fruit. The control of the production of biologically active compounds by the rhizosphere fungal community provides new opportunities to increase the industrial and medicinal value of the fruit of C. migao.

scholarly journals In vitro study of human osteoblast proliferation and morphology on orthodontic mini-implants

2015 ◽  
Vol 85 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Ricardo Carvalho Bueno ◽  
Roberta Tarkany Basting
Keyword(s):  
Chemical Composition ◽  
In Vitro Study ◽  
Chemical Components ◽  
Control Group ◽  
Osteoblast Proliferation ◽  
Mini Implants ◽  
Significant Difference ◽  
Implant Anchorage ◽  
Positive Effect

ABSTRACT Objective:  To evaluate the proliferation and morphology of human osteoblasts cultured on two brands of mini-implants after 24, 48, and 72 hours, in addition to the chemical composition found on their surface. Materials and Methods:  Two brands of mini-implant (Morelli and Neodent) were evaluated; polystyrene was used as a control group (n  =  3). Osteoblasts were cultured on the surface of sterilized mini-implants in a CO2 incubator at different time periods (24, 48, and 72 hours). Osteoblast proliferation was quantified by scanning electron microscopy using up to 5000× magnification, and cell morphology was analyzed by a single observer. For the chemical analysis, spectroscopy X-ray fluorescence was used to identify and quantify chemical components on the surface of the mini-implants. Results:  Two-way ANOVA showed no significant interaction between the factors studied (P  =  0.686). A Tukey test revealed no significant difference in osteoblast proliferation between the mini-implants at all studied periods; however, a difference in cell proliferation was detected between the Neodent and the control group (P  =  .025). For all groups, time had a direct and positive effect on osteoblast proliferation (P < .001). The significant elements present in both brands of mini-implants were titanium, aluminum, vanadium, and iron. Conclusions:  Osteoblast proliferation was present on the mini-implants studied, which increased over time; however, no significant difference between brands was observed. No difference was seen between the mini-implants evaluated in terms of chemical composition. Cell adhesion after 72 hours suggests that areas of bone remodeling can be achieved, thus initiating the process of mini-implant anchorage.

scholarly journals Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques

2015 ◽  
Vol 15 (8) ◽  
pp. 4161-4178 ◽  
Author(s):  
A. Worringen ◽  
K. Kandler ◽  
N. Benker ◽  
T. Dirsch ◽  
S. Mertes ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Metal Oxides ◽  
Relative Number ◽  
Carbonaceous Material ◽  
Submicron Particles ◽  
Research Station ◽  
Mixing State ◽  
Separation Techniques ◽  
Potential Measurement ◽  
Virtual Impactor

Abstract. In the present work, three different techniques to separate ice-nucleating particles (INPs) as well as ice particle residuals (IPRs) from non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed-phase clouds and allow after evaporation in the instrument for the analysis of the residuals. The Fast Ice Nucleus Chamber (FINCH) coupled with the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated particles for analysis. The instruments were run during a joint field campaign which took place in January and February 2013 at the High Alpine Research Station Jungfraujoch (Switzerland). INPs and IPRs were analyzed offline by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Online analysis of the size and chemical composition of INP activated in FINCH was performed by laser ablation mass spectrometry. With all three INP/IPR separation techniques high abundances (median 20–70%) of instrumental contamination artifacts were observed (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). After removal of the instrumental contamination particles, silicates, Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types obtained by all three techniques. In addition, considerable amounts (median abundance mostly a few percent) of soluble material (e.g., sea salt, sulfates) were observed. As these soluble particles are often not expected to act as INP/IPR, we consider them as potential measurement artifacts. Minor types of INP/IPR include soot and Pb-bearing particles. The Pb-bearing particles are mainly present as an internal mixture with other particle types. Most samples showed a maximum of the INP/IPR size distribution at 200–400 nm in geometric diameter. In a few cases, a second supermicron maximum was identified. Soot/carbonaceous material and metal oxides were present mainly in the sub-micrometer range. Silicates and Ca-rich particles were mainly found with diameters above 1 μm (using ISI and FINCH), in contrast to the Ice-CVI which also sampled many submicron particles of both groups. Due to changing meteorological conditions, the INP/IPR composition was highly variable if different samples were compared. Thus, the observed discrepancies between the different separation techniques may partly result from the non-parallel sampling. The differences of the particle group relative number abundance as well as the mixing state of INP/IPR clearly demonstrate the need of further studies to better understand the influence of the separation techniques on the INP/IPR chemical composition. Also, it must be concluded that the abundance of contamination artifacts in the separated INP and IPR is generally large and should be corrected for, emphasizing the need for the accompanying chemical measurements. Thus, further work is needed to allow for routine operation of the three separation techniques investigated.

scholarly journals Particle hygroscopicity and its link to chemical composition in the urban atmosphere of Beijing, China during summertime

2015 ◽  
Vol 15 (8) ◽  
pp. 11495-11524 ◽  
Author(s):  
Z. J. Wu ◽  
J. Zheng ◽  
D. J. Shang ◽  
Z. F. Du ◽  
Y. S. Wu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Concentration ◽  
Cloud Condensation Nuclei ◽  
Empirical Relationship ◽  
Urban Atmosphere ◽  
High Time Resolution ◽  
Hygroscopic Growth ◽  
Hygroscopic Properties ◽  
Beijing China ◽  
Measurement Period

Abstract. Simultaneous measurements of particle number size distribution, particle hygroscopic properties, and size-resolved chemical composition were made during the summer of 2014 in Beijing, China. During the measurement period, the median hygroscopicity parameters (κ) of 50, 100, 150, 200, and 250 nm particles are respectively 0.15, 0.19, 0.22, 0.27, and 0.29, showing an increasing trend with increasing particle size. When PM2.5 mass concentration is greater than 50 μg m−3, the fractions of the hydrophilic mode for 150, 250, 350 nm particles increased towards 1 as PM2.5 mass concentration increased. This indicates that aged particles dominated during severe pollution periods in the atmosphere of Beijing. Particle hygroscopic growth can be well predicted using high time-resolution size-resolved chemical composition derived from AMS measurement on a basis of ZSR mixing rule. An empirical relationship between κ of organic fraction (κorg) and oxygen to carbon ratio (O : C) (κorg= 0.08·O : C+0.02) is obtained. During new particle formation event associating with strongly active photochemistry, the hygroscopic growth factor or κ of newly formed particles is greater than for particle with the same sizes during non-NPF periods. A quick transformation from external mixture to internal mixture for pre-existing particles (for example 250 nm particle) was observed. Such transformations can modify the state of mixture of pre-exiting particles and thus modify properties such as the light absorption coefficient and cloud condensation nuclei activation.

CHEMICAL COMPOSITION OF HYPHAL AND SCLEROTIAL WALLS OF SCLEROTIUM ROLFSII SACC.

1967 ◽  
Vol 13 (2) ◽  
pp. 137-141 ◽  
Author(s):  
I. Chet ◽  
Y. Henis ◽  
R. Mitchell
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Acid Hydrolysis ◽  
Sclerotium Rolfsii ◽  
Ash Content ◽  
Chemical Degradation ◽  
Chemical Components

The chemical components of the sclerotial and hyphal walls of the fungus Sclerotium rolfsii Sacc. are compared. Sclerotial walls contain a melanin-like pigment which is absent from hyphal walls. They are also higher in non-hydro-lyzable residue, in lipids, and in ash content. In both walls, glucose, mannose, and glucosamine are found after acid hydrolysis. Acid hydrolysates of sclerotial and hyphal walls contain 10 and 13 amino acids, respectively, L-arginine, L-serine, and L-proline being absent from sclerotial walls. The possible role of some of these components in the resistance of the sclerotia to biological and chemical degradation is discussed.

scholarly journals Bone Chemical Composition Analysis Using Photoacoustic Technique

2020 ◽  
Vol 8 ◽  
Author(s):  
Ting Feng ◽  
Yejing Xie ◽  
Weiya Xie ◽  
Dean Ta ◽  
Qian Cheng
Keyword(s):  
Chemical Composition ◽  
Optical Absorption ◽  
Imaging Techniques ◽  
Diagnostic Technique ◽  
High Sensitivity ◽  
Spectral Unmixing ◽  
Chemical Components ◽  
Composition Analysis ◽  
Feasibility Assessment ◽  
Multi Wavelength

Photoacoustic (PA) signal analysis based on ultrasonic wave detection can provide both high-sensitivity optical contrast information and micro-architectural information which is highly related with the chemical composition of tissue. In this study, the feasibility assessment of bone composition assessment was investigated using the multi-wavelength PA analysis (MWPA) method which could reflect the molecular information. By illuminating a bone specimen using a laser light with wavelength over an optical spectrum ranging from 680 to 950 nm, the optical absorption spectrum of the bone was acquired. Then, with the optical absorption spectra of all optical absorption chemical components in the known bone, a spectral unmixing procedure was performed to quantitatively assess the relative content of each chemical component. The experimental results from rabbit bones show that MWPA method can be used to assess chemical components related to bone metabolism. Our study confirmed that PA technique can be used as a novel bone diagnostic technique by providing new information about the quantity of bone and identifying biomarkers of bone that can improve the current diagnostic imaging techniques.

Chemical Composition and Repellency of Cinnamomum japonicum Leaf-Derived Essential Oil against Aedes albopictus

2013 ◽  
Vol 295-298 ◽  
pp. 35-38 ◽  
Author(s):  
Ying Hui Peng ◽  
Li Juan Jiang ◽  
Li Wang ◽  
Yu Duo Lu ◽  
Kai Yu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Essential Oil ◽  
Aedes Albopictus ◽  
Chemical Components ◽  
Mosquito Repellent ◽  
Main Components

The repellent activitie of Cinnamomum japonicum oil against Aedes albopictus were investigated. The main volatile chemical components of the oil were qualitatively studied. The main results are given as follows. Cinnamomum japonicum oil providing absolute protection against Ae. albopictus in laboratory and field for 2.33 ± 0.63 h, 3.85 ± 0.21 h at concentration of 1.5 mg/cm2, respectively. A total of 28 compounds were identified. The main components of the essential oil were borneoll (28.30%), 1,8-cCineole (20.98%), (-)-bBornyl acetate (6.65%), linalool (5.94%), (-)-.alpha.-terpinol (5.87%), caryophyllene oxlde (5.11%). The results indicates that Cinnamomum japonicum oil has a great potential to be developed into a ecofriendly mosquito repellent.

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