Analysis of extinction properties as a function of relative humidity using a κ-EC-Mie model in Nanjing

Abstract. The relationship between relative humidity (RH) and extinction properties is of widespread concern. In this study, a hygroscopic parameter (κ) and the volume fraction of elemental carbon (EC) were used to characterize the chemical characteristics of particles, and a core-shell model was built based on these characteristics. The size distribution, chemical compositions and RH were measured in Nanjing from 15/10/2013 to 13/11/2013. The extinction coefficients of particles were fitted with the BHCOAT program, and the values correlated well with the measured values (R2 = 0.81), which suggested that the core-shell model was reasonable. The results show that more than 83 % of the extinction in Nanjing was due to particles in the 0.2–1.0 μm size range. Under dry conditions, the higher mass fraction of particles in the 0.2–1.0 μm size range caused the higher volume extinction coefficient. An increase in RH led to a significant increase in the extinction coefficient, although the increases differed among the different size segments. The corresponding functions are given in this study. For λ = 550 nm, the extinction contributions of the 0.01–0.2 μm, 0.2–0.5 μm, and 1.0–2.0 μm size ranges increased significantly with the increase in RH, whereas the extinction contributions of the 0.5–1.0 μm and 2.0–10.0 μm size ranges decreased slightly.

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Analysis of extinction properties as a function of relative humidity using a <i>κ</i>-EC-Mie model in Nanjing

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-4147-2017 ◽

2017 ◽

Vol 17 (6) ◽

pp. 4147-4157 ◽

Cited By ~ 7

Author(s):

Zefeng Zhang ◽

Yan Shen ◽

Yanwei Li ◽

Bin Zhu ◽

Xingna Yu

Keyword(s):

Relative Humidity ◽

Shell Model ◽

Extinction Coefficient ◽

Size Range ◽

Volume Fraction ◽

Core Shell ◽

Extinction Coefficients ◽

Dry Conditions ◽

Coated Spheres ◽

The Relationship

Abstract. The relationship between relative humidity (RH) and extinction properties is of widespread concern. In this study, a hygroscopic parameter (κ) and the volume fraction of elemental carbon (EC) were used to characterize the chemical characteristics of particles, and a core-shell model was built based on these characteristics. The size distribution, chemical composition, and RH were measured in Nanjing from 15 October to 13 November 2013. The model-derived extinction coefficients of particles were fit with the program of coated spheres according to Bohren and Huffman (2008) (BHCOAT), and the modeled values correlated well with the measurement-derived extinction coefficients (r2 = 0. 81), which suggested that the core-shell model produced reasonable results. The results show that more than 81 % of the extinction coefficient in Nanjing was due to particles in the 0.2–1.0 µm size range. Under dry conditions, the higher mass fraction of particles in the 0.2–1.0 µm size range caused the higher extinction coefficient. An increase in RH led to a significant increase in the extinction coefficient, although the increases differed among the different size segments. For λ = 550 nm, the extinction coefficient from the 0.01–0.2, 0.2–0.5, and 1.0–2.0 µm size ranges increased significantly with the increase in RH, whereas the extinction contributions from the 0.5–1.0 and 2.0–10.0 µm size ranges to the extinction coefficient decreased slightly.

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Simplified Core-Shell Model of Biochar - Iron Ore Mixture for Calculation of Effective Permittivity and Permeability

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.279.240 ◽

2018 ◽

Vol 279 ◽

pp. 240-244

Author(s):

Anton P. Anzulevich ◽

Igor V. Bychkov ◽

Vasiliy D. Buchelnikov ◽

Zhi Wei Peng ◽

Zhu Cheng Huang ◽

...

Keyword(s):

Shell Model ◽

Iron Ore ◽

Volume Fraction ◽

Effective Permittivity ◽

Effective Medium ◽

Simplified Model ◽

Effective Medium Approximation ◽

Core Shell ◽

Permittivity And Permeability ◽

Shell Particles

The simplified model of biochar-bearing iron ore with binder was studied. It was considered a mixture of two types of core-shell particles, ‘iron ore – binder’ particles and ‘biochar – binder’ particles. The expressions to calculate complex effective permittivity and permeability was derived by effective medium approximation (EMA). The corresponding dependencies on volume fraction of iron ore in the mixture are provided.

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EL NINO RELATED CLIMATE AND DENGUE FEVER CASES IN JEDDAH, SAUDI ARABIA

FLORA AND FAUNA ◽

10.33451/florafauna.v25i1pp91-99 ◽

2019 ◽

Vol 25 (1) ◽

Author(s):

MASROOR ALI KHAN ◽

KHALID AL GHAMDI ◽

JAZEM A. MEHYOUB ◽

RAKHSHAN KHAN

Keyword(s):

Relative Humidity ◽

Dengue Fever ◽

El Niño ◽

Significant Relationship ◽

El Nino ◽

Climate Data ◽

Light Traps ◽

Mosquito Abundance ◽

Dengue Transmission ◽

The Relationship

The focus of this study is to find the relationship between El Nino and dengue fever cases in the study area.Mosquito density was recorded with the help of light traps and through aspirators collection. Climate data were obtained from National Meteorology and Environment centre. (Year wise El Nino and La Nina data are according to NOAA & Golden Gate Weather Services). Statistical methods were used to establish the correlation coefficient between different factors. A high significant relationship was observed between Relative Humidity and Dengue fever cases, but Aedes abundance had no significant relationship with either Relative humidity and Temperature. Our conclusion is that the El Nino does not affect the dengue transmission and Aedes mosquito abundance in this region, which is supported by earlier works.

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Spatiotemporal Variation of the Burned Area and Its Relationship with Climatic Factors in Central Kazakhstan

Remote Sensing ◽

10.3390/rs13020313 ◽

2021 ◽

Vol 13 (2) ◽

pp. 313

Author(s):

Yongfang Xu ◽

Zhaohui Lin ◽

Chenglai Wu

Keyword(s):

Soil Moisture ◽

Relative Humidity ◽

Central Asia ◽

Climatic Factors ◽

Spatiotemporal Variation ◽

Lower Atmosphere ◽

Burned Area ◽

Circulation Index ◽

Precipitation Anomalies ◽

The Relationship

Central Asia is prone to wildfires, but the relationship between wildfires and climatic factors in this area is still not clear. In this study, the spatiotemporal variation in wildfire activities across Central Asia during 1997–2016 in terms of the burned area (BA) was investigated with Global Fire Emission Database version 4s (GFED4s). The relationship between BA and climatic factors in the region was also analyzed. The results reveal that more than 90% of the BA across Central Asia is located in Kazakhstan. The peak BA occurs from June to September, and remarkable interannual variation in wildfire activities occurs in western central Kazakhstan (WCKZ). At the interannual scale, the BA is negatively correlated with precipitation (correlation coefficient r = −0.66), soil moisture (r = −0.68), and relative humidity (r = −0.65), while it is positively correlated with the frequency of hot days (r = 0.37) during the burning season (from June to September). Composite analysis suggests that the years in which the BA is higher are generally associated with positive geopotential height anomalies at 500 hPa over the WCKZ region, which lead to the strengthening of the downdraft at 500 hPa and the weakening of westerlies at 850 hPa over the region. The weakened westerlies suppress the transport of water vapor from the Atlantic Ocean to the WCKZ region, resulting in decreased precipitation, soil moisture, and relative humidity in the lower atmosphere over the WCKZ region; these conditions promote an increase in BA throughout the region. Moreover, the westerly circulation index is positively correlated (r = 0.53) with precipitation anomalies and negatively correlated (r = −0.37) with BA anomalies in the WCKZ region during the burning season, which further underscores that wildfires associated with atmospheric circulation systems are becoming an increasingly important component of the relationship between climate and wildfire.

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CLAY-INORGANIC STUDIES. II. HYDROXY ALUMINUM PHOSPHATE–MONTMORILLONITE COMPLEX

Canadian Journal of Soil Science ◽

10.4141/cjss75-030 ◽

1975 ◽

Vol 55 (2) ◽

pp. 225-233 ◽

Cited By ~ 3

Author(s):

H. KODAMA ◽

M. D. WEBBER

Keyword(s):

Relative Humidity ◽

Room Temperature ◽

Aluminum Phosphate ◽

Silicate Layer ◽

Basal Spacing ◽

Minor Amount ◽

Chemical Compositions ◽

A Minor ◽

Positively Charged ◽

Water Contents

Two specimens of hydroxy aluminum phosphate interlayer materials in montmorillonite clay were prepared with 7.20 meq Al and 11.29 meq H3PO4/g clay and with 14.40 meq Al and 22.58 meq H3PO4/g clay, and the resulting complexes studied by chemical and mineralogical methods. Both interlayer materials were slightly positively charged and except for different water contents their chemical compositions were almost identical. They contained Al, PO4 and H2O and a minor amount of Ca and approximated hydrous AlPO4∙nH2O. The mole ratios of Al:Ca:PO4:OH were 1.00:0.08:0.92:0.24 and 1.00:0.05:0.91:0.24, respectively. The interlayer materials appeared to be loosely packed and distributed sparsely in interspaces of the montmorillonite. The degree of packing was greater for the preparation with the larger amount of interlayer material. The materials increased the montmorillonite basal spacing to 23.3 Å under air-dry condition (30–40% relative humidity) but did not affect the lateral dimensions. The basal spacing varied somewhat with relative humidity at room temperature and decreased markedly as water was driven off by heating. Heat treatments between room temperature and 300 C sharply reduced the d001 spacings to 16.7 Å which persisted up to 700 C. It is postulated that the large basal spacings occur because the hydrated interlayer materials have a framework structure with tunnels along the c-axis. This being so, changes in the spacings with different humidities might result from the movement of water molecules among interstitial spaces existing around and between the loosely distributed molecules of interlayer material. The 16.7 Å spacing for the dehydrated phase corresponds to the sum of 7.0 Å, the edge dimension of an orthorhombic anhydrous AlPO4 and 9.7 Å, the silicate layer thickness.

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Estimation of Interlayer Thickness in Inorganic Particulate-Filled Polymer Composites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705711404724 ◽

2011 ◽

Vol 24 (6) ◽

pp. 777-788 ◽

Cited By ~ 3

Author(s):

J.Z. Liang

Keyword(s):

Polymer Composites ◽

Volume Fraction ◽

Particle Diameter ◽

Interfacial Structure ◽

Interlayer Thickness ◽

Filled Polymer ◽

Mechanical And Physical Properties ◽

The Relationship ◽

Good Agreement

The structure of the interlayer between matrix and inclusions affect directly the mechanical and physical properties of inorganic particulate-filled polymer composites. The interlayer thickness is an important parameter for characterization of the interfacial structure. The effects of the interlayer between the filler particles and matrix on the mechanical properties of polymer composites were analyzed in this article. On the basis of a simplified model of interlayer, an expression for estimating the interlayer thickness ([Formula: see text]) was proposed. In addition, the relationship between the [Formula: see text] and the particle size and its concentration was discussed. The results showed that the calculations of the [Formula: see text] and thickness/particle diameter ratio ([Formula: see text]) increased nonlinearly with an increase of the volume fraction of the inclusions. Moreover, the predictions of [Formula: see text] and the relevant data reported in literature were compared, and good agreement was found between them.

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Effect of Three Ca Sources Applied On Peanuts I. Productivity and Seed Quality1

Peanut Science ◽

10.3146/i0095-3679-7-1-6 ◽

1980 ◽

Vol 7 (1) ◽

pp. 19-25 ◽

Cited By ~ 13

Author(s):

D. L. Hallock ◽

A. H. Allison

Keyword(s):

Crop Yields ◽

Relative Effectiveness ◽

Correlation Coefficients ◽

Early Flowering ◽

Lower Yield ◽

Flowering Stage ◽

Arachis Hypogaea L ◽

Dry Conditions ◽

Increase Productivity ◽

The Relationship

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.

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