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Al-Rubaei, A. M., Engström, M., Viklander, M. & Blecken, G.-T. (2017). Effectiveness of a 19-Year Old Combined Pond-Wetland System in Removing Particulate and Dissolved Pollutants. Wetlands (Wilmington, N.C.), 37(3), 485-496
Open this publication in new window or tab >>Effectiveness of a 19-Year Old Combined Pond-Wetland System in Removing Particulate and Dissolved Pollutants
2017 (English)In: Wetlands (Wilmington, N.C.), ISSN 0277-5212, E-ISSN 1943-6246, Vol. 37, no 3, p. 485-496Article in journal (Refereed) Published
Abstract [en]

This study monitored the stormwater runoff quantity and quality treatment performance of a 6.8 ha 19-year old combined pond-wetland system, located in south Sweden, over one year. The mean volume reductions for 53 storm events for the pond and wetland were 40% and 28%, respectively, while the mean flow reductions were 60% and 76%, respectively. Pollutant concentrations in the influent to the wetland were highly variable. The pond-wetland system could efficiently remove an average of 91%, 80%, 94%, 91%, 83% and 92% of TSS, TP, particulate Cd, Cu, Pb, and Zn, respectively, whereas the removal of particulate and dissolved Ni was highly variable with an average of 67% ± 62% and −5% ± 41%, respectively. The removal of TN, NH4-N and NO3 + NO2-N was highly variable with an average of 45% ± 27%, 12% ± 96% and 45% ± 43%, respectively. These removal percentages are high in comparison to other studies and underline that relatively old systems can also provide efficient treatment. Although the pond accounted for a substantial reduction of pollutant concentration, the wetland significantly enhanced both the treatment performance and the peak flow reduction. This underlines that a combined pond/wetland system is a more beneficial solution than a pond only. The pollutant removal efficiency was significantly influenced by some factors including Antecedent Dry Days, seasonal variations, air temperature, retention times, rainfall depth and duration, and peak rainfall intensity.

Place, publisher, year, edition, pages
Springer, 2017
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-62268 (URN)10.1007/s13157-017-0884-6 (DOI)000403573000008 ()2-s2.0-85014039169 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-06-27 (rokbeg)

Available from: 2017-03-02 Created: 2017-03-02 Last updated: 2018-07-10Bibliographically approved
Merriman, L. S., Moore, T., Wang, J., Osmond, D., Al-Rubaei, A., Smolek, A., . . . Hunt, W. F. (2017). Evaluation of factors affecting soil carbon sequestration services of stormwater wet retention ponds in varying climate zones.. Science of the Total Environment, 583, 133-141
Open this publication in new window or tab >>Evaluation of factors affecting soil carbon sequestration services of stormwater wet retention ponds in varying climate zones.
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2017 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 583, p. 133-141Article in journal (Refereed) Published
Abstract [en]

The carbon sequestration services of stormwater wet retention ponds were investigated in four different climates: U.S., Northern Sweden, Southern Sweden, and Singapore, representing a range of annual mean temperatures, growing season lengths and rainfall depths: geographic factors that were not statistically compared, but have great effect on carbon (C) accumulation. A chronosequence was used to estimate C accumulations rates; C accumulation and decomposition rates were not directly measured. C accumulated significantly over time in vegetated shallow water areas (0–30 cm) in the USA (78.4 g C m− 2 yr− 1), in vegetated temporary inundation zones in Sweden (75.8 g C m− 2 yr− 1), and in all ponds in Singapore (135 g C m− 2 yr− 1). Vegetative production appeared to exert a stronger influence on relative C accumulation rates than decomposition. Comparing among the four climatic zones, the effects of increasing rainfall and growing season lengths (vegetative production) outweighed the effects of higher temperature on decomposition rates. Littoral vegetation was a significant source to the soil C pool relative to C sources draining from watersheds. Establishment of vegetation in the shallow water zones of retention ponds is vital to providing a C source to the soil. Thus, the width of littoral shelves containing this vegetation along the perimeter may be increased if C sequestration is a design goal. This assessment establishes that stormwater wet retention ponds can sequester C across different climate zones with generally annual rainfall and lengths of growing season being important general factors for C accumulation.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-61478 (URN)10.1016/j.scitotenv.2017.01.040 (DOI)000394556400015 ()28104334 (PubMedID)2-s2.0-85009781834 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-07 (rokbeg)

Available from: 2017-01-17 Created: 2017-01-17 Last updated: 2018-09-13Bibliographically approved
Blecken, G.-T., Hunt, W. F., Al-Rubaei, A., Viklander, M. & Lord, W. G. (2017). Stormwater control measure (SCM) maintenance considerations to ensure designed functionality (ed.). Urban Water Journal, 14(3), 278-290
Open this publication in new window or tab >>Stormwater control measure (SCM) maintenance considerations to ensure designed functionality
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2017 (English)In: Urban Water Journal, ISSN 1573-062X, Vol. 14, no 3, p. 278-290Article in journal (Refereed) Published
Abstract [en]

Great investment is made in the design and installation of stormwater control measures (SCMs). Substantial research investment, too, is made to optimise the performance of SCMs. However, once installed, SCMs often suffer from lack of maintenance or even outright neglect. Key maintenance needs for wet ponds, constructed stormwater wetlands, bioretention, infiltration practices, permeable pavement, swales, and rainwater harvesting systems are reviewed with many tasks, such as the cleaning of pre-treatment areas and the preservation of infiltration surfaces, being common maintenance themes among SCMs. Consequences of lacking maintenance are illustrated (mainly insufficient function or failure). Probable reasons for neglect include insufficient communication, unclear responsibilities, lack of knowledge, financial barriers, and decentralised measures. In future designs and research, maintenance (and lack thereof) should be considered. Assessing the performance of SCMs conservatively and including safety factors may prevent consequences of under-maintenance; and requiring regular inspection may help to enforce sufficient maintenance.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-4643 (URN)10.1080/1573062X.2015.1111913 (DOI)000392208900006 ()2-s2.0-84948128243 (Scopus ID)29de70bf-15f3-41ca-a578-a30a6632d186 (Local ID)29de70bf-15f3-41ca-a578-a30a6632d186 (Archive number)29de70bf-15f3-41ca-a578-a30a6632d186 (OAI)
Note

Validerad; 2017; Nivå 2; 2017-01-16 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-11-15Bibliographically approved
Al-Rubaei, A., Merriman, L. S., Hunt, W. F., Viklander, M., Marsalek, J. & Blecken, G.-T. (2017). Survey of the operational status of 25 Swedish municipal stormwater management ponds. Journal of environmental engineering, 143(6), Article ID 05017001.
Open this publication in new window or tab >>Survey of the operational status of 25 Swedish municipal stormwater management ponds
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2017 (English)In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 143, no 6, article id 05017001Article in journal (Refereed) Published
Abstract [en]

During the past 50 years, wet stormwater ponds have been constructed to reduce negative environmental impacts of urban stormwater discharges on receiving aquatic environments. However, in many jurisdictions there is little information on the current operational status of such ponds and their functioning. This paucity of information prompted a field survey of 25 Swedish municipal stormwater ponds, aged between 3 and 26 years. The pond survey focused on estimating the pond hydraulic loading and efficiency, the state of littoral vegetation, characteristics of bottom sediment in the inlet and outlet zones (sizes and the chemistry), and the overall operational pond status, including the access for maintenance. The hydraulic efficiencies of ponds were estimated for pond footprint shapes and relative locations of the inlets and outlets using literature data. The estimated hydraulic efficiencies correlated well with the pond length-to-width ratios and the ratio of the pond surface area to the impervious area of the runoff contributing catchment (i.e., the hydraulic loading). Littoral vegetation was inspected visually and found to be overgrown at some facilities, which impeded the maintenance access. Benthic sediments in ponds contained silt and clay (&lt;63&#x2009;&#x2009;&#x3BC;m" role="presentation" style="box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;"><63  μm<63  μm), sand and gravel fractions, and when compared with the literature data, such sediments appeared relatively coarse. Chemical characteristics of sediments reflected anthropogenic (traffic) activities, but without excessive contamination warranting special disposal requirements. Of the 25 ponds surveyed, four were fenced off and inaccessible to machinery. In fact, the design of these four ponds was such that it made inspection and maintenance very difficult, which may pose potential risks to ponds operation. Fifty-four percent of the investigated ponds were in need of minor maintenance, primarily because of sediment and litter accumulation in their inflow and outflow sections. The fact that the inspection survey revealed relatively few minor issues that could be corrected easily demonstrates the importance of relatively simple regular inspections serving to detect minor problems at an early stage before they would seriously impact pond functioning. The above survey methodology should be helpful for developing similar low-cost surveys in other jurisdictions.

Place, publisher, year, edition, pages
American Society of Civil Engineers (ASCE), 2017
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-61982 (URN)10.1061/(ASCE)EE.1943-7870.0001203 (DOI)000399657100007 ()2-s2.0-85021873825 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-04-25 (rokbeg)

Available from: 2017-02-14 Created: 2017-02-14 Last updated: 2018-07-10Bibliographically approved
Winston, R., Al-Rubaei, A., Blecken, G.-T. & Hunt, W. F. (2016). A Simple Infiltration Test for Determination of Permeable Pavement Maintenance Needs (ed.). Journal of environmental engineering, 142(10), Article ID 6016005.
Open this publication in new window or tab >>A Simple Infiltration Test for Determination of Permeable Pavement Maintenance Needs
2016 (English)In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 142, no 10, article id 6016005Article in journal (Refereed) Published
Abstract [en]

Permeable pavements allow stormwater to pass through the pavement surface, filtering out sediment and debris; over time, regular preventative maintenance will be needed to maintain the pavement surface infiltration rate (IR). IR testing is commonly used to determine maintenance needs and frequencies. ASTM standard methods may be used to measure permeable pavement IR; however, these tests can take hours to complete and require infiltrometers not readily available to maintenance contractors. A simple infiltration test (SIT) has been devised which (1) is conducted using easily acquired materials, (2) has a larger surface area (i.e., more representative of average pavement conditions), and (3) requires, on average, 72% less time to conduct than the ASTM test. ASTM and SIT methods were compared by conducting a total of 873 IR tests at the same locations on 12 permeable pavements in North Carolina, Ohio, and Sweden. Results showed that (1) a segmented linear relationship related SIT and ASTM-measured IRs; (2) the SIT and ASTM tests predicted approximately the same IR up to 250  mm/min 250  mm/min; (3) the larger surface area of the SIT reduced the variability in measurements (average 40% less) compared to the ASTM method. The SIT took one-quarter the time to run, on average, making this newly-devised tool more efficient when assessing IR than ASTM methods, potentially saving maintenance personnel time and money.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-9189 (URN)10.1061/(ASCE)EE.1943-7870.0001121 (DOI)000384244700011 ()2-s2.0-84988375056 (Scopus ID)7c04eb4b-da61-480e-8819-10bef0989425 (Local ID)7c04eb4b-da61-480e-8819-10bef0989425 (Archive number)7c04eb4b-da61-480e-8819-10bef0989425 (OAI)
Note

Validerad; 2016; Nivå 2; 2016-10-26 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Al-Rubaei, A., Engström, M., Viklander, M. & Blecken, G.-T. (2016). Long-term hydraulic and treatment performance of a 19-year old constructed stormwater wetland: Finally maturated or in need of maintenance? (ed.). Ecological Engineering: The Journal of Ecotechnology, 95, 73-82
Open this publication in new window or tab >>Long-term hydraulic and treatment performance of a 19-year old constructed stormwater wetland: Finally maturated or in need of maintenance?
2016 (English)In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 95, p. 73-82Article in journal (Refereed) Published
Abstract [en]

Constructed stormwater wetlands (CSWs) are a commonly used measure for stormwater retention and quality treatment. However, although questions have been raised about the long-term performance of CSWs, only a few studies have targeted this issue and none have evaluated the performance of CSWs more than approximately 5–10 years old. Further, most studies have not examined the development of the long-term performance of CSWs but delivered a snapshot at a certain point of time. The present study investigated the performance of a 19-year-old CSW in Växjö, Sweden, treating stormwater from a 320-ha urban catchment. Besides removal of sediment from the CSW’s forebay, no other maintenance had been conducted. However, regular inspections had been performed. The results of the present sampling campaign were compared to two existing datasets collected at the same CSW after three years of operation in 1997 and nine years of operation in 2003. The CSW was found to provide efficient peak flow reduction and, depending on the event characteristics, also volume reduction. It still treated stormwater effectively: removal of Cd, Cu, Pb, Zn, TSS and TP event mean concentrations were between 89 and 96%, whereas mean concentrations of TN were reduced by 59%. The load removal efficiencies were even higher. Comparative analysis of the three monitoring periods based on the load removal efficiency revealed that the CSW, despite the lack of maintenance, performed more efficiently and stably for most pollutants compared to when newly constructed. This underlines the importance of the establishment and maturation of constructed wetland systems. Overall, the results showed that CSWs are resilient systems, which if designed well and regularly inspected to prevent major issues, can work efficiently for at least two decades.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-5262 (URN)10.1016/j.ecoleng.2016.06.031 (DOI)000385371400011 ()2-s2.0-84976645087 (Scopus ID)3525b565-b119-4f62-9385-cdb695f0efcb (Local ID)3525b565-b119-4f62-9385-cdb695f0efcb (Archive number)3525b565-b119-4f62-9385-cdb695f0efcb (OAI)
Note

Validerad; 2016; Nivå 2; 20160702 (ahmed)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Al-Rubaei, A. (2016). Long-Term Performance, Operation and Maintenance Needs of Stormwater Control Measures (ed.). (Doctoral dissertation). Paper presented at .
Open this publication in new window or tab >>Long-Term Performance, Operation and Maintenance Needs of Stormwater Control Measures
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-17899 (URN)5c7128ad-7f0b-4b9b-9104-ee4c986645ca (Local ID)978-91-7583-603-4 (ISBN)978-91-7583-604-1 (ISBN)5c7128ad-7f0b-4b9b-9104-ee4c986645ca (Archive number)5c7128ad-7f0b-4b9b-9104-ee4c986645ca (OAI)
Note
För återvalidering; 2016; 20160502 (ahmed); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Ahmed Mohammed Qassim Al-Rubaei Ämne: VA-teknik/Urban Water Engineering Avhandling: Long-Term Performance, Operation and Maintenance Needs of Stormwater Control Measures Opponent: Associate Professor Elizabeth Fassman-Beck, Departement of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, New Jersey, USA. Ordförande: Professor Maria Viklander, Avdelningen för Arkitektur och vatten, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet, Luleå. Tid: Torsdag 9 juni 2016, kl 10.00 Plats: A109, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-05-18Bibliographically approved
Winston, R., Al-Rubaei, A., Blecken, G.-T., Viklander, M. & Hunt, W. (2016). Maintenance measures for preservation and recovery of permeable pavement surface infiltration rate: The effects of street sweeping, vacuum cleaning, high pressure washing, and milling (ed.). Journal of Environmental Management, 169, 132-144
Open this publication in new window or tab >>Maintenance measures for preservation and recovery of permeable pavement surface infiltration rate: The effects of street sweeping, vacuum cleaning, high pressure washing, and milling
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2016 (English)In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 169, p. 132-144Article in journal (Refereed) Published
Abstract [en]

The surface infiltration rates (SIR) of permeable pavements decline with time as sediment and debris clog pore spaces. Effective maintenance techniques are needed to ensure the hydraulic functionality and water quality benefits of this stormwater control. Eight different small-scale and full-scale maintenance techniques aimed at recovering pavement permeability were evaluated at ten different permeable pavement sites in the USA and Sweden. Maintenance techniques included manual removal of the upper 2 cm of fill material, mechanical street sweeping, regenerative-air street sweeping, vacuum street sweeping, hand-held vacuuming, high pressure washing, and milling of porous asphalt. The removal of the upper 2 cm of clogging material did not significantly improve the SIR of concrete grid paves (CGP) and permeable interlocking concrete pavers (PICP) due to the inclusion of fines in the joint and bedding stone during construction, suggesting routine maintenance cannot overcome improper construction. For porous asphalt maintenance, industrial hand-held vacuum cleaning, pressure washing, and milling were increasingly successful at recovering the SIR. Milling to a depth of 2.5 cm nearly restored the SIR for a 21-year old porous asphalt pavement to like-new conditions. For PICP, street sweepers employing suction were shown to be preferable to mechanical sweepers; additionally, maintenance efforts may become more intensive over time to maintain a threshold SIR, as maintenance was not 100% effective at removing clogging material.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-16125 (URN)10.1016/j.jenvman.2015.12.026 (DOI)000370909500015 ()26735865 (PubMedID)2-s2.0-84951803586 (Scopus ID)fb3c3926-9fc8-46e1-8042-689ef2d11706 (Local ID)fb3c3926-9fc8-46e1-8042-689ef2d11706 (Archive number)fb3c3926-9fc8-46e1-8042-689ef2d11706 (OAI)
Note

Validerad; 2016; Nivå 2; 20151229 (ahmed)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Al-Rubaei, A., Viklander, M. & Blecken, G.-T. (2015). Long-term hydraulic performance of stormwater infiltration systems (ed.). Paper presented at . Urban Water Journal, 12(8), 660-671
Open this publication in new window or tab >>Long-term hydraulic performance of stormwater infiltration systems
2015 (English)In: Urban Water Journal, ISSN 1573-062X, Vol. 12, no 8, p. 660-671Article in journal (Refereed) Published
Abstract [en]

Despite the common use of stormwater infiltration systems, there is still only limited data available evaluating the long-term hydraulic function of such systems. The hydraulic performance of twelve stormwater infiltration systems (vegetated and unvegetated concrete grid pavers, unvegetated interlocking concrete pavers and grassed swales) was therefore investigated in field and laboratory environments in Växjö, Sweden. The systems investigated had not been subjected to regular maintenance to sustain infiltration capacity. Due to this, and the fact that, for most systems, an inappropriate joint filling material was used and (at the swales) there was severe compaction, most systems showed a reduced infiltration capacity. Despite this, especially the older vegetated systems, were still capable of infiltrating intense design rainfalls. This study showed the influence of some factors (type and age of the system, the type of joint filling material (grass and macadam) and the distance from the edge of the pavement) on the long-term behaviour of the infiltration capacity. In conclusion, there is a significant risk that existing stormwater infiltration systems are not working adequately in praxis. Proper implementation of construction and regular control by the inspecting authority has to be ensured.

National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-13253 (URN)10.1080/1573062X.2014.949796 (DOI)000364942900007 ()2-s2.0-84941168338 (Scopus ID)c71dcb81-0b82-4547-a773-c55b7e805833 (Local ID)c71dcb81-0b82-4547-a773-c55b7e805833 (Archive number)c71dcb81-0b82-4547-a773-c55b7e805833 (OAI)
Note
Validerad; 2015; Nivå 2; 20140917 (ahmed)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Al-Rubaei, A., Engström, M., Viklander, M. & Blecken, G.-T. (2014). Long-term treatment efficiency of a constructed stormwater wetland: preliminary results (ed.). Paper presented at International Conference on Urban Drainage : 07/09/2014 - 12/09/2014. Paper presented at International Conference on Urban Drainage : 07/09/2014 - 12/09/2014.
Open this publication in new window or tab >>Long-term treatment efficiency of a constructed stormwater wetland: preliminary results
2014 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Constructed stormwater wetlands (CSWs) are commonly used in Sweden and worldwide because of their high efficiency in urban stormwater management. However, questions have been raised about the long-term performance of CSWs. This study investigated the performance of a 19-year-old constructed wetland, which was designed to treat the stormwater from a 320-ha catchment located in the city of Växjö, southern Sweden. The system has not been maintained since its construction in 1994. The results of the present study were compared with results obtained from a previous study conducted by Växjö Municipality in 1997. The results showed that the CSW significantly reduced peak flows by 72%. High concentration reductions were found for Cd, Cr, Cu, Zn, Pb, TSS and TP (90, 89, 91, 90, 96, 96 and 86%, respectively). TN concentrations were reduced by 61%. The results indicated that lack of maintenance had no effect on the performance of wetland system during this long period of operation (19 years). In contrast, especially the removal of Cu and nitrogen was enhanced compared to 1997, which may be due to maturing of the system. The results show that CSWs are resilient systems, which (provided that design is sufficient) can work efficiently for at least two decades.

Keywords
Civil engineering and architecture - Water engineering, Samhällsbyggnadsteknik och arkitektur - Vattenteknik
National Category
Water Engineering
Research subject
Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-28629 (URN)27e8f859-54c9-4e3e-b017-04af827d1737 (Local ID)27e8f859-54c9-4e3e-b017-04af827d1737 (Archive number)27e8f859-54c9-4e3e-b017-04af827d1737 (OAI)
Conference
International Conference on Urban Drainage : 07/09/2014 - 12/09/2014
Note
Godkänd; 2014; 20140917 (ahmed)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-05-18Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2002-1373

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