60,502 research outputs found
Examination of Pervious Pavement Pore Parameters with X-Ray Tomography
No full textPervious pavement (PP) is an infrastructure material that can alter rainfall-runoff relationships, filter particulate matter (PM), and
sequester runoff constituents. Beyond a measure of total porosity ( φt), less-commonly measured pore parameters and relationships thereof
influence these phenomena. In this study, cementitious PP (CPP), used as a permeable surface for an exfiltration system loaded by runoff, was examined. X-ray tomography (XRT) was utilized to examine pore size and frequency, generate a total-to-effective porosity (φt − φe) relation- ship, quantify pore tortuosity (Le=L), and relationships for specific surface area (SSA), pore-size distributions ðPSDÞpore, and φt. Gravimetric analyses were used for SSA based on mass ðSSAÞs as well as validation of XRT porosity. Results indicate that φt ranged from 10 to 30% while φe ranged from 4 to 27%. Relationships for (φt − φe), SSA, φt, and median pore diameter (d50n) were represented with a power law model (PLM). Using φt the ðSSAÞpt of pores ranged from 11,000 to 19,000 m2=m3 while for φe, ðSSAÞpe ranged from 12,000 to 21,000 m2=m3. XRT results show that the ðPSDÞpore is hetero-disperse. (Le=L) ranged from 2.9 to 5.9, compared to 1.4 for a monodisperse and uniform distribution of pore sizes. The ðLe=LÞ-φt relationship and probability density function (pdf) of (Le=L) were Gaussian. Beyond the common index of φt, these parameters are building blocks for infiltration, filtration, evaporation, storage, and reaction components of models such as the storm water management model (SWMM) and computationalfluid Dynamics (CFD
Traces and shards of self-injury: Strange accounting with “Author X”
No full textIn this strange account autoethnography, three or four authors explore their lived experiences with self-injury. Strange accounting is both a post-modern style of text, and a method for keeping identities concealed when risks and secrets are in play. Author X, a post-modern place-keeper for an anonymous author who may or may not have contributed to this manuscript, introduces a new dimension and layer of concealment. With Author X in-play and under erasure, the reader will never be sure if there were three or four authors on this manuscript. Through strange accounting, a post-structuralist/postmodernist frame will be applied to understanding the self-injury experience. We frame self-injury as a social practice and, for some, an everyday norm, while remaining acutely aware of the stigma surrounding the topic of self-injury. Each of us, coupled with Author X, provide the others cover to trace stories of self-injury through the literature, our flesh, and our lives
Abacarus wuyiensis Kuang & Zhuo 1987
No full text<i>Abacarus wuyiensis</i> Kuang & Zhuo, 1987. (Kuang & Zhuo, 1987) <p> <i>Abacarus wuyiensis</i> Kuang & Zhuo, 1987: 380 –381.</p> <p> <i>Abacarus wuyiensis</i> Kuang & Zhuo. Kuang, 1995: 144.</p> <p> <i>Material examined</i></p> <p> 11 females, from <i>Bambusa</i> sp. (Gramineae). Baotianman (33°31.00’N, 111°55.85’E), Neixiang County, Henan Province, P. R. China, 22 July 2004, coll. X.­F. Xue.</p> <p> <i>Relation to host</i></p> <p>Vagrant on leaf surface. No damage to the host was observed.</p> <p> <i>Distribution</i></p> <p>China (Fujian, Guangxi, Jiangsu, Henan).</p>Published as part of <i>Xue, Xiao-Feng & Hong, Xiao-Yue, 2006, Eriophyoid mite fauna from Henan Province, central China (Acari: Eriophyoidea) with descriptions of five new species, pp. 1-30 in Zootaxa 1204</i> on page 15, DOI: <a href="http://zenodo.org/record/172352">10.5281/zenodo.172352</a>
Pore-structure models of hydraulic conductivity for permeable pavement
No full textPermeable pavement functions as a porous infrastructure interface allowing the infiltration and evaporation
of rainfall–runoff while functioning as a relatively smooth load-bearing surface for vehicular transport.
Hydraulic conductivity (k) of permeable pavement is an important hydraulic property and is a
function of the pore structure. This study examines k for a cementitious permeable pavement (CPP)
through a series of pore-structure models. Measurements utilized include hydraulic head as well as total
porosity, (/t), effective porosity (/e), tortuosity (Le/L) and pore size distribution (PSD) indices generated
through X-ray tomography (XRT). XRT results indicate that the permeable pavement pore matrix is hetero-
disperse, with high tortuosity and /t – /e. Power law models of k–/t and k–/e relationships are
developed for a CPP mix design. Results indicate that the Krüger, Fair-Hatch, Hazen, Slichter, Beyer
and Terzaghi models based on simple pore-structure indices do not reproduce measured k values. The
conventional Kozeny–Carman model (KCM), a more parameterized pore-structure model, did not reproduce
measured k values. This study proposes a modified KCM utilizing /e, specific surface area (SSA)pe
and weighted tortuosity (Le/L)w. Results demonstrate that such permeable pavement pore-structure
parameters with the modified KCM can predict k. The k results are combined with continuous simulation
modeling using historical rainfall to provide nomographs examining permeable pavement as a low
impact development (LID) infrastructure componen
Neotetra bambusae Kuang 1998
No full text<i>Neotetra bambusae</i> Kuang, 1998. (Kuang, 1998) <p> <i>Neotetra bambusae</i> Kuang, 1998: 57 –59.</p> <p> <i>Material examined</i></p> <p> 8 females and 3 males, from <i>Bambusa</i> sp. (Gramineae), Longyuwan (33°42.53’N, 111°45.62’E), Luanchuan County, Henan Province, P. R. China, 19 July 2004, coll. X.­F. Xue.</p> <p> <i>Relation to host</i></p> <p>Vagrant on leaf surface. No damage to the host was observed.</p> <p> <i>Distribution</i></p> <p>China (Jiangsu, Henan).</p>Published as part of <i>Xue, Xiao-Feng & Hong, Xiao-Yue, 2006, Eriophyoid mite fauna from Henan Province, central China (Acari: Eriophyoidea) with descriptions of five new species, pp. 1-30 in Zootaxa 1204</i> on page 23, DOI: <a href="http://zenodo.org/record/172352">10.5281/zenodo.172352</a>
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
A comparative study of the leaves of Cat hay a argyrophylla Chun & Kuang and three species of Keteleeria Carrière
No full textDetails of the cuticular, epidermal and anatomical features of the leaves of Cathaya argyrophylla Chun & Kuang, are described and compared with those of three species of Keteleeria (K. davidiana (Bertrand) Beissner, K. fortunei (Murray) Carriere, and K. chien-peii Flous). The study supports the creation of Cathaya Chun & Kuang as a new genus of the Pinaceae
Filtration and clogging of permeable pavement loaded by urban drainage
No full textPermeable pavement, as a sustainable infrastructure material can promote hydrologic
restoration, particulate matter (PM) and solute control. However, filtration and commensurate
clogging are two aspects of continued interest and discussion. This study quantifies
filtration and clogging of cementitious permeable pavement (CPP) for loadings from 50 to
200 mg/L of hetero-disperse sandy-silt PM. The CPP mix design provides a hetero-disperse
pore size distribution (PSD)pore, effective porosity (4e) of 24% and median pore size of
658 mm with a standard deviation of 457 mm. The PM mass separation across the entire
particle size distribution (PSD)PM exceeds 80%; with complete separation for PM greater
than 300 mm and 50% separation for suspended PM. Turbidity is reduced (42e95%), and
effluent is below 10 NTU in the first quartile of a loading period. Permeable pavement
illustrates reductions in initial (clean-bed) hydraulic conductivity (k0) with loading time. For
all PM loadings, k0 (3.1 101 mm/s) was reduced to 104 mm/s for runoff loading durations
from 100 to 250 h, respectively. Temporal hydraulic conductivity (k) follows exponential
profiles. Maintenance by vacuuming and sonication illustrate that 96e99% of k0 is recovered.
Permeable pavement constitutive properties integrated with measured PM loads and
a year of continuous rainfall-runoff simulation illustrate k reduction with historical loadings.
Study results measure and model filtration and hydraulic conductivity phenomena as
well as maintenance requirements of permeable pavement directly loaded by urban
drainag
Dataset of global urban expansion in 2000-2020
No full text1. This is the dataset described by the report "Global Urban Land Cover Changes in 2000-2020" submitted to Global Ecosystem and Environment Observation Analysis Research Cooperation (GEOARC).
2. The dataset includes the following subsets, i.e. global urban boundary (named as "GUB_Year_Continent.tif", like "GUB_2000_Africa.tif").See the description document for details.
3. The detail information of datasets is listed in Description.xlsx
4. If you have any questions, please contact Wenhui Kuang ([email protected]).
5.Related publications with this dataset.
(1)Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300.
(2)Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China’s urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82.
(3) Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974.
(4) Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China’s 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929.
(5) Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747.
(6) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606.
(7) Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828.
(8) Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834.
(9) Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515
Dataset of impervious surface area and green space fractions of global urban land in 2000-2020
No full text1. This is the dataset described by the report "Global Urban Land Cover Changes in 2000-2020" submitted to Global Ecosystem and Environment Observation Analysis Research Cooperation (GEOARC).
2. The dataset includes the following subsets, i.e. global impervious surface area fraction (named as "GISA_Year_Continent.tif", like "GISA_2000_Africa.tif"), global urban green space fraction (named as "GUGS_Year_Continent.tif", like "GUGS_2000_Africa.tif"), See the description document for details.
3. The global impervious surface area and global urban green space datasets are showed by the percentage in a grid. In order for data storage, the data were amplified by 100 times and converted into integer storage.
4. The detail information of datasets is listed in Description.xlsx
5. If you have any questions, please contact Wenhui Kuang ([email protected]).
6.Related publications with this dataset.
(1)Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300.
(2)Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China’s urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82.
(3) Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974.
(4) Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China’s 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929.
(5) Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747.
(6) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606.
(7) Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828.
(8) Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834.
(9) Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515
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