1,300 research outputs found

    Independent Validation of the SWMM Green Roof Module

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    Green roofs are a popular Sustainable Drainage Systems (SuDS) technology. They provide multiple benefits, amongst which the retention of rainfall and detention of runoff are of particular interest to stormwater engineers. The hydrological performance of green roofs has been represented in various models, including the Storm Water Management Model (SWMM). The latest version of SWMM includes a new LID green roof module, which makes it possible to model the hydrological performance of a green roof by directly defining the physical parameters of a green roof’s three layers. However, to date, no study has validated the capability of this module for representing the hydrological performance of an extensive green roof in response to actual rainfall events. In this study, data from a previously-monitored extensive green roof test bed has been utilised to validate the SWMM green roof module for both long-term (173 events over a year) and short-term (per-event) simulations. With only 0.357% difference between measured and modelled annual retention, the uncalibrated model provided good estimates of total annual retention, but the modelled runoff depths deviated significantly from the measured data at certain times (particularly during summer) in the year. Retention results improved (with the difference between modelled and measured annual retention decreasing to 0.169% and the Nash-Sutcliffe Model Efficiency (NSME) coefficient for per-event rainfall depth reaching 0.948) when reductions in actual evapotranspiration due to reduced substrate moisture availability during prolonged dry conditions were used to provide revised estimates of monthly ET. However, this aspect of the model’s performance is ultimately limited by the failure to account for the influence of substrate moisture on actual ET rates. With significant differences existing between measured and simulated runoff and NSME coefficients of below 0.5, the uncalibrated model failed to provide reasonable predictions of the green roof’s detention performance, although this was significantly improved through calibration. To precisely model the hydrological behaviour of an extensive green roof with a plastic board drainage layer, some of the modelling structures in SWMM green roof module require further refinement

    The dumortierite supergroup. I. A new nomenclature for the dumortierite and holtite groups

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    Although the distinction between magnesiodumortieite and dumortierite, i.e. Mg vs. Al dominance at the partially vacant octahedral Al1 site, had met current criteria of the IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) for distinguishing mineral species, the distinction between holtite and dumortierite had not, since Al and Si are dominant over Ta and (Sb, As) at the Al1 and two Si sites, respectively, in both minerals. Recent studies have revealed extensive solid solution between Al, Ti, Ta and Nb at Al1 and between Si, As and Sb at the two Si sites or nearly coincident (As, Sb) sites in dumortierite and holtite, further blurring the distinction between the two minerals. This situation necessitated revision in the nomenclature of the dumortierite group. The newly constituted dumortierite supergroup, space group Pnma (no. 62), comprises two groups and six minerals, one of which is the first member of a potential third group, all isostructural with dumortierite. The supergroup, which has been approved by the CNMNC, is based on more specific end-member compositions for dumortierite and holtite, in which occupancy of the Al1 site is critical. (1) Dumortierite group, with Al1 = Al^(3+), Mg^(2+) and 〈, where 〈 denotes cation vacancy. Charge balance is provided by OH substitution for O at the O2, O7 and O10 sites. In addition to dumortierite, endmember composition AlAl_6Bsi_3O_(18), and magnesiodumortierite, endmember composition MgAl_6Bsi_3O_(17)(OH), plus three endmembers, “hydroxydumortierite”, 〈Al_6Bsi_3O_(15)(OH)_3 and two Mg-Ti analogues of dumortierite, (Mg_(0.5)Ti_(0.5))Al_6Bsi_3O_(18) and (Mg_(0.5)Ti_(0.5))Mg_2Al_4Bsi_3O_(16)(OH)_2, none of which correspond to mineral species. Three more hypothetical endmembers are derived by homovalent substitutions of Fe^(3+) for Al and Fe^(2+) for Mg. (2) Holtite group, with Al1 = Ta^(5+), Nb^(5+), Ti^(4+) and 〈. In contrast to the dumortierite group, vacancies serve not only to balance the extra charge introduced by the incorporation of pentavalent and quadrivalent cations for trivalent cations at Al1, but also to reduce repulsion between the highly charged cations. This group includes holtite, endmember composition (Ta_(0.6)〈_(0.4))Al_6Bsi_3O_(18), nioboholite (2012-68), endmember composition (Nb_(0.6)〈_(0.4_)Al_6Bsi_3O_(18), and titanoholtite (2012-69), endmember composition (Ti_(0.75)〈_(0.25))Al_6Bsi_3O_(18). (3) Szklaryite (2012-70) with Al1 = 〈 and an endmember formula 〈Al_6Bas^(3+)_ 3O_(15). Vacancies at Al1 are caused by loss of O at O2 and O7, which coordinate the Al1 with the Si sites, due to replacement of Si^(4+) by As^(3+) and Sb^(3+), and thus this mineral does not belong in either the dumortierite or the holtite group. Although szklaryite is distinguished by the mechanism introducing vacancies at the Al1 site, the primary criterion for identifying it is based on occupancy of the Si/As, Sb sites: (As^(3+) + Sb^(3+)) > Si^(4+) consistent with the dominant-valency rule. A Sb^(3+) analogue to szklaryite is possible

    The dumortierite supergroup. II. Three new minerals from the Szklary pegmatite, SW Poland: Nioboholtite, (Nb_(0.6)〈_(0.4))Al_6Bsi_3O_(18), titanoholtite, (Ti_(0.75)〈_(0.25))Al_6Bsi_3O_(18), and szklaryite 〈Al_6Bas^(3+)_ 3O_(15)

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    Three new minerals in the dumortierite supergroup were discovered in the Szklary pegmatite, Lower Silesia, Poland. Nioboholtite, endmember (Nb_(0.6)〈_(0.4))Al_6B_3Si_3O_(18), and titanoholtite, endmember (Ti_(0.75)〈_(0.25))Al_6B_3Si_3O_(18), are new members of the holtite group, whereas szklaryite, endmember 〈Al_6Bas^(3+)_ 3O_(15), is the first representative of a potential new group. Nioboholtite occurs mostly as overgrowths not exceeding 10 ÎŒm in thickness on cores of holtite. Titanoholtite forms patches up to 10 ÎŒm across in the holtite cores and streaks up to 5 ÎŒm wide along boundaries between holtite cores and the nioboholtite rims. Szklaryite is found as a patch ∌2 ÎŒm in size in As- and Sb- bearing dumortierite enclosed in quartz. Titanoholtite crystallized almost simultaneously with holtite and other Ta-dominant minerals such as tantalite-(Mn) and stibiotantalite and before nioboholtite, which crystallized simultaneously with stibiocolumbite during decreasing Ta activity in the pegmatite melt. Szklaryite crystallized after nioboholtite during the final stage of the Szklary pegmatite formation. Optical properties could be obtained only from nioboholtite, which is creamy-white to brownish yellow or grey-yellow in hand specimen, translucent, with a white streak, biaxial (–), n_α = 1.740 – 1.747, n_ÎČ âˆŒ 1.76, n_Îł ∌ 1.76, and Δ < 0.020. Electron microprobe analyses of nioboholtite, titanoholtite and szklaryite give, respectively, in wt.%: P_2O_5 0.26, 0.01, 0.68; Nb_2O_55.21, 0.67, 0.17; Ta_2O_5 0.66, 1.18, 0.00; SiO_2 18.68, 21.92, 12.78; TiO_2 0.11, 4.00, 0.30; B_2O_3 4.91, 4.64, 5.44; Al_2O_3 49.74, 50.02, 50.74; As_2O_3 5.92, 2.26, 16.02; Sb_2O_3 10.81, 11.48, 10.31; FeO 0.51, 0.13, 0.19; H_2O (calc.) 0.05, –, –, Sum 96.86, 96.34, 97.07, corresponding on the basis of O = 18–As–Sb to {(Nb_(0.26)Ta_(0.02)〈_(0.18)) (Al_(0.27)Fe_(0.05)Ti_(0.01))〈_(0.21)}_(ÎŁ1.00)Al_6B_(0.92){Si_(2.03)P_(0.02)(Sb_(0.48)As_(0.39)Al_(0.07)}_(ÎŁ3.00)(O_(17.09)OH_(0.04)〈_(0.87))_(ÎŁ18.00), {(Ti_(0.32) Nb_(0.03)Ta_(0.03)〈_(0.10) )(Al_(0.3 5) Ti_(0.01) Fe_(0.01))〈_(0.15)}_(ÎŁ1.00) Al_6 B_(0.86) {Si_(2.36) (Sb_(0.51) As_(0.14) )}_(ÎŁ3.01)(O_(17.35)〈_(0.65))_(ÎŁ18.00) and {〈_(0.53) (Al_(0.41) Ti_(0.02) Fe_(0.02))(Nb_(0.01)〈_(0.01) )}_(ÎŁ1.00)Al_6 B_(1.01) {(As_(1.07) Sb_(0.47) Al_(0.03)) Si_(1.37) P_(0.06)}_(ÎŁ3.00)(O_(16.46)〈_(1.54))_(ÎŁ18.00). Electron backscattered diffraction indicates that the three minerals are presumably isostructural with dumortierite, that is, orthorhombic symmetry, space group Pnma (no. 62), and unit-cell parameters close to a = 4.7001, b = 11.828, c = 20.243 Å, with V = 1125.36 Å^3 and Z = 4; micro-Raman spectroscopy provided further confirmation of the structural relationship for nioboholtite and titanoholtite. The calculated density is 3.72 g/cm^3 for nioboholtite, 3.66 g/cm^3 for titanoholtite and 3.71 g/cm^3 for szklaryite. The strongest lines in X-ray powder diffraction patterns calculated from the cell parameters of dumortierite of Moore and Araki (1978) and the empirical formulae of nioboholtite, titanoholtite and szklaryite are [d, Å, I (hkl)]: 10.2125, 67, 46, 19 (011); 5.9140, 40, 47, 57 (020); 5.8610, 66, 78, 100 (013); 3.4582, 63, 63, 60 (122); 3.4439, 36, 36, 34 (104); 3.2305, 100, 100, 95 (123); 3.0675, 53, 53, 50 (105); 2.9305, 65, 59, 51 (026); 2.8945, 64, 65, 59 (132), respectively. The three minerals have been approved by the IMA CNMNC (IMA 2012-068, 069, 070) and were named for their relationship to holtite and occurrence in the Szklary pegmatite, respectively

    Occultocarpon, a new monotypic genus of Gnomoniaceae on Alnus nepalensis from China

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    Microfungi in the Gnomoniaceae (Diaporthales, Ascomycetes) comprise species commonly reported as pathogens and endophytes on trees and herbaceous hosts primarily from temperate forests of North America, Europe, and Japan. The diversity of Gnomoniaceae in China is poorly known, although several plant families that occur there specifically the Betulaceae are considered important hosts. An exploratory trip to Yunnan, China, resulted in the discovery of several members of the Gnomoniaceae. In this paper a new monotypic genus, Occultocarpon and its species, O. ailaoshanense, are described and illustrated. A phylogeny based on three genes (LSU, rpb2, tef1-α) reveals that O. ailaoshanense belongs to the Gnomoniaceae and forms a branch distinct from the currently known genera. Occultocarpon ailaoshanense is characterized by perithecia with thin, central to eccentric necks in groups embedded in a stroma and oblong elliptical-elongated, one-septate ascospores. Occultocarpon ailaoshanense occurs on the bark of branches of Alnus nepalensis (Betulaceae) in Yunnan, ChinaMicrofungi in the Gnomoniaceae (Diaporthales, Ascomycetes) comprise species commonly reported as pathogens and endophytes on trees and herbaceous hosts primarily from temperate forests of North America, Europe, and Japan. The diversity of Gnomoniaceae in China is poorly known, although several plant families that occur there specifically the Betulaceae are considered important hosts. An exploratory trip to Yunnan, China, resulted in the discovery of several members of the Gnomoniaceae. In this paper a new monotypic genus, Occultocarpon and its species, O. ailaoshanense, are described and illustrated. A phylogeny based on three genes (LSU, rpb2, tef1-α) reveals that O. ailaoshanense belongs to the Gnomoniaceae and forms a branch distinct from the currently known genera. Occultocarpon ailaoshanense is characterized by perithecia with thin, central to eccentric necks in groups embedded in a stroma and oblong elliptical-elongated, one-septate ascospores. Occultocarpon ailaoshanense occurs on the bark of branches of Alnus nepalensis (Betulaceae) in Yunnan, Chin

    Ambient and cold-temperature infrared spectra and XRD patterns of ammoniated phyllosilicates and carbonaceous chondrite meteorites relevant to Ceres and other solar system bodies

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    Mg‐phyllosilicate‐bearing, dark surface materials on the dwarf planet Ceres have NH_4‐bearing materials, indicated by a distinctive 3.06 ÎŒm absorption feature. To constrain the identity of the Ceres NH_4‐carrier phase(s), we ammoniated ground particulates of candidate materials to compare their spectral properties to infrared data acquired by Dawn's Visible and Infrared (VIR) imaging spectrometer. We treated Mg‐, Fe‐, and Al‐smectite clay minerals; Mg‐serpentines; Mg‐chlorite; and a suite of carbonaceous meteorites with NH_4‐acetate to exchange ammonium. Serpentines and chlorites showed no evidence for ammoniation, as expected due to their lack of exchangeable interlayer sites. Most smectites showed evidence for ammoniation by incorporation of NH_4^+ into their interlayers, resulting in the appearance of absorptions from 3.02 to 3.08 ÎŒm. Meteorite samples tested had weak absorptions between 3.0 and 3.1 ÎŒm but showed little clear evidence for enhancement upon ammoniation, likely due to the high proportion of serpentine and other minerals relative to expandable smectite phases or to NH_4^+ complexing with organics or other constituents. The wavelength position of the smectite NH4 absorption showed no variation between IR spectra acquired under dry‐air purge at 25 °C and under vacuum at 25 °C to −180 °C. Collectively, data from the smectite samples show that the precise center wavelength of the characteristic ~3.05 ÎŒm v_3 absorption in NH_4 is variable and is likely related to the degree of hydrogen bonding of NH_4‐H_2O complexes. Comparison with Dawn VIR spectra indicates that the hypothesis of Mg‐saponite as the ammonium carrier phase is the simplest explanation for observed data, and that Ceres dark materials may be like Cold Bokkeveld or Tagish Lake but with proportionally more Mg‐smectite

    Tissintite, (Ca,Na,□)AlSi_2O_6: A Shock-Induced Clinopyroxene in the Tissint Meteorite

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    During a nanomineralogy investigation of the Tissint Martian meteorite, we discovered the new shock-induced mineral tissintite, (Ca,Na,□)AlSi_2O_6, which is named after Tissint, Morocco, where the host meteorite fell. This phase provides new insights into shock conditions and impact processes on Mars. Here, we emphasize the origin of tissintite (IMA 2013-027) and demonstrate how nanomineralogy can play an important role in meteorite and Mars rock research

    Identification of HLA-DRPheÎČ47 as the susceptibility marker of hypersensitivity to beryllium in individuals lacking the berylliosis-associated supratypic marker HLA-DPGluÎČ69

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    BACKGROUND: Susceptibility to beryllium (Be)-hypersensitivity (BH) has been associated with HLA-DP alleles carrying a glutamate at position 69 of the HLA-DP ÎČ-chain (HLA-DPGlu69) and with several HLA-DP, -DQ and -DR alleles and polymorphisms. However, no genetic associations have been found between BH affected subjects not carrying the HLA-DPGlu69 susceptibility marker. METHODS: In this report, we re-evaluated an already described patient populations after 7 years of follow-up including new 29 identified BH subjects. An overall population 36 berylliosis patients and 38 Be-sensitization without lung granulomas and 86 Be-exposed controls was analysed to assess the role of the individual HLA-class II polymorphisms associated with BH-susceptibility in HLA-DPGlu69 negative subjects by univariate and multivariate analysis. RESULTS: As previously observed in this population the HLA-DPGlu69 markers was present in higher frequency in berylliosis patients (31 out of 36, 86%) than in Be-sensitized (21 out of 38, 55%, p = 0.008 vs berylliosis) and 41 out of 86 (48%, p < 0.0001 vs berylliosis, p = 0.55 vs Be-sensitized) Be-exposed controls. However, 22 subjects presenting BH did not carry the HLA-DPGlu69 marker. We thus evaluated the contribution of all the HLA-DR, -DP and -DQ polymorphisms in determining BH susceptibility in this subgroup of HLA-Glu69 subjects. In HLA-DPGlu69-negatives a significant association with BH was found for the HLA-DQLeu26, for the HLA-DRB1 locus residues Ser13, Tyr26, His32, Asn37, Phe47 and Arg74 and for the HLA-DRB3 locus clusterized residues Arg11, Tyr26, Asp28, Leu38, Ser60 and Arg74. HLA-DRPhe47 (OR 2.956, p < 0.05) resulting independently associated with BH. Further, Be-stimulated T-cell proliferation in the HLA-DPGlu69-negative subjects (all carrying HLA-DRPhe47) was inhibited by the anti-HLA-DR antibody (range 70–92% inhibition) significantly more than by the anti-HLA-DP antibody (range: 6–29%; p < 0.02 compared to anti-HLA-DR) while it was not affected by the anti-HLA-DQ antibody. CONCLUSION: We conclude that HLA-DPGlu69 is the primary marker of Be-hypersensitivity and HLA-DRPhe47 is associated with BH in Glu69-negative subjects, likely playing a role in Be-presentation and sensitization

    Building social capital through breastfeeding peer support: Insights from an evaluation of a voluntary breastfeeding peer support service in North-West England

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    Background: Peer support is reported to be a key method to help build social capital in communities. To date there are no studies that describe how this can be achieved through a breastfeeding peer support service. In this paper we present findings from an evaluation of a voluntary model of breastfeeding peer support in North-West England to describe how the service was operationalized and embedded into the community. This study was undertaken from May, 2012 to May, 2013. Methods: Interviews (group or individual) were held with 87 participants: 24 breastfeeding women, 13 peer supporters and 50 health and community professionals. The data contained within 23 monthly monitoring reports (January, 2011 to February 2013) compiled by the voluntary peer support service were also extracted and analysed. Results: Thematic analysis was undertaken using social capital concepts as a theoretical lens. Key findings were identified to resonate with ’bonding’, ‘bridging’ and ‘linking’ forms of social capital. These insights illuminate how the peer support service facilitates ‘bonds’ with its members, and within and between women who access the service; how the service ‘bridges’ with individuals from different interests and backgrounds, and how ‘links’ were forged with those in authority to gain access and reach to women and to promote a breastfeeding culture. Some of the tensions highlighted within the social capital literature were also identified. Conclusions: Horizontal and vertical relationships forged between the peer support service and community members enabled peer support to be embedded into care pathways, helped to promote positive attitudes to breastfeeding and to disseminate knowledge and maximise reach for breastfeeding support across the community. Further effort to engage with those of different ethnic backgrounds and to resolve tensions between peer supporters and health professionals is warranted
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