METAL DEPOSITION IN A FLAT GREEN ROOF SYSTEM IN A MEXICO CITY BUILDING

2002 ◽  
Vol 12 (03n04) ◽  
pp. 225-230
Author(s):  
JUAN A. ASPIAZU F. ◽  
JOSE LOPEZ M. ◽  
JESUS RAMIREZ T. ◽  
PEDRO VILLASEÑOR S. ◽  
ALICIA GALNARES DEL C. ◽  
...  

It is well known that green roof systems are being used to improve the environment by reducing the summer temperatures inside the houses and to capture atmospheric contaminants. The Universidad Autónoma de Chapingo had begun a project to test the latter possibility in Mexico City, were some roofs were covered with the plant Sedum praealtum L. By PIXE analysis, metal concentrations were determined in ashes of the leaves and stems. The concentrations were compared with those of the substrata and plantations grown in a greenhouse, which were used as a reference. Preliminary results are presented.

2021 ◽  
Vol 13 (13) ◽  
pp. 7115
Author(s):  
Mostafa Kazemi ◽  
Luc Courard ◽  
Julien Hubert

A green roof is composed of a substrate and drainage layers which are fixed on insulation material and roof structure. The global heat resistance (Rc) within a green roof is affected by the humidity content of the substrate layer in which the coarse recycled materials can be used. Moreover, the utilization of recycled coarse aggregates such as incinerated municipal solid waste aggregate (IMSWA) for the drainage layer would be a promising solution, increasing the recycling of secondary resources and saving natural resources. Therefore, this paper aims to investigate the heat transfer across green roof systems with a drainage layer of IMSWA and a substrate layer including recycled tiles and bricks in wet and dry states according to ISO-conversion method. Based on the results, water easily flows through the IMSWAs with a size of 7 mm. Meanwhile, the Rc-value of the green roof system with the dry substrate (1.26 m2 K/W) was 1.7 times more than that of the green roof system with the unsaturated substrate (0.735 m2 K/W). This means that the presence of air-spaces in the dry substrate provided more heat resistance, positively contributing to heat transfer decrease, which is also dependent on the drainage effect of IMSWA. In addition, the Rc-value of the dry substrate layer was about twice that of IMSWA as the drainage layer. No significant difference was observed between the Rc-values of the unsaturated substrate layer and the IMSWA layer.


2008 ◽  
Vol 33 (1) ◽  
pp. 173-177 ◽  
Author(s):  
A. Spala ◽  
H.S. Bagiorgas ◽  
M.N. Assimakopoulos ◽  
J. Kalavrouziotis ◽  
D. Matthopoulos ◽  
...  

2009 ◽  
Vol 33 (12) ◽  
pp. 1059-1069 ◽  
Author(s):  
Aikaterini Sfakianaki ◽  
Elli Pagalou ◽  
Konstantinos Pavlou ◽  
Mat Santamouris ◽  
M. N. Assimakopoulos

2005 ◽  
Vol 5 (3) ◽  
pp. 4143-4182 ◽  
Author(s):  
D. Salcedo ◽  
K. Dzepina ◽  
T. B. Onasch ◽  
M. R. Canagaratna ◽  
Q. Zhang ◽  
...  

Abstract. An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at the CENICA Supersite, while another was deployed in the Aerodyne Mobile Laboratory (AML) during the Mexico City Metropolitan Area field study (MCMA-2003) from 31 March–4 May 2003 to investigate particle concentrations, sources, and processes. This is the first of a series of papers reporting the AMS results from this campaign. The AMS provides real time information on mass concentration and composition of the non-refractory species in particulate matter less than 1 µm (NR-PM1) with high time and size-resolution. For the first time, we report field results from a beam width probe, which was used to study the shape and mixing state of the particles and to quantify potential losses of irregular particles due to beam broadening inside the AMS. Data from this probe show that no significant amount of irregular particles was lost due to excessive beam broadening. A comparison of the CENICA and AML AMSs measurements is presented, being the first published intercomparison between two quadrupole AMSs. The speciation, and mass concentrations reported by the two AMSs compared relatively well. The differences found are likely due to the different inlets used in both instruments. In order to account for the refractory material in the aerosol, we also present measurements of Black Carbon (BC) using an aethalometer and an estimate of the aerosol soil component obtained from Proton-Induced X-ray Emission Spectrometry (PIXE) analysis of impactor substrates. Comparisons of AMS + BC + soil mass concentration with other collocated particle instruments (a LASAIR Optical Particle Counter, a Tapered Element Oscillating Microbalance (TEOM) and a DustTrak Aerosol Monitor) are also presented. The comparisons show that the AMS + BC + soil mass concentration during MCMA-2003 is a good approximation to the total PM2.5 mass concentration.


2021 ◽  
Vol 67 (3-4) ◽  
pp. 149-155
Author(s):  
Har'el Agra ◽  
Hadar Shalom ◽  
Omar Bawab ◽  
Gyongyver J. Kadas ◽  
Leon Blaustein

Abstract Green roofs are expected to contribute to higher biodiversity in urban surroundings. Typically, green roofs have been designed with low plant diversity. However, plant diversity can be enhanced by controlling resource availability and creating distinct niches. Here we hypothesize that by using different drainage heights during the short plant-growing season in a semi-arid green roof system we can create distinct niches and plant communities. Our experiment took place at the University of Haifa, north Israel. We tested three different heights of drainage outlet: 10 cm under the surface of the substrate (Low), 1 cm under the surface of the substrate (Medium) and 3 cm above the surface of the substrate (High) on plant species-composition in green-roof gardens. Grasses cover was higher in High and Medium drainages while forbs cover was higher in Low drainage. Species richness was the highest in Low drainage while diversity indices showed the opposite trend. We conclude that by changing the height of the drainage we can create different niches and change species composition in a short time period of one growing season. This way we can create more diverse green roof communities and enhance biodiversity in urban areas, particularly in semi-arid regions.


2019 ◽  
Vol 274 ◽  
pp. 04001
Author(s):  
Maria Manso ◽  
João Castro-Gomes

This study presents the work developed with alkali activated mixtures to be used as component of a new modular green wall and green roof system (GEOGREEN). The aim is to find the most appropriate composition of alkali-activated mixture to maximize water absorption and porosity and also find a good mechanical strength with reduced density. Alkali-activated mixtures were produced using two precursors, mine waste mud from Panasqueira mine (W) and ground waste glass (G) and two alkaline activators, sodium silicate (SS) and sodium hydroxide (SH). A ventilated oven was used to speed up the curing process. Variables as percentage substitution of W per G, molar concentration of SH, cure length and temperature, were tested to identify the reference mixture. After these tests different percentages of aggregates as sand (S), expanded cork granules (C) and expanded clay (A) were added to reference mixture (REF). Results indicate that S25 obtained the maximum compressive strength of 35 MPa after 7 curing days. However, about 30% compressive strength loss is observed after immersion of this mixture in water for 24h. Capillary absorption coefficient can reach to 4,77 kg/m2.h0,5 with C25 and to 4,11 kg/m2.h0,5 with S25. Also C50 enables a 20% density reduction compared to REF.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2082 ◽  
Author(s):  
Li Liu ◽  
Liwei Sun ◽  
Jie Niu ◽  
William J. Riley

The Middle and Lower Reaches of the Yangtze River (MLRYR) region, which has humid subtropical climate conditions and unique plum rain season, is characterized by a simultaneous high-frequency urban flooding and reduction in groundwater levels. Retrofitting the existing buildings into green roofs is a promising approach to combat urban flooding, especially for a densely developed city. Here, the application potential of the Green Roof System (GRS) and the Improved Green Roof System (IGRS) designed to divert overflowing water from green roofs to recharge groundwater were analyzed in a densely developed city, Nanchang, China. For the first time, the influence of GRS on the hydraulic condition of Combined Sewage System/Storm Water System (CSS/SWS) is analyzed, which is a direct reflection of the effect of GRS on alleviating urban flooding. The simulation results show that GRS can retain about 41–75% of precipitation in a 2-hour timescale and the flooding volumes in the GRS/IGRS region are 82% and 28% less than those of the Traditional Roof System (TRS) in 10- and 100-yr precipitation events, respectively. In the continuous simulations, GRS also enhances Evapotranspiration (ET), which accounts for 39% of annual precipitation, so that reduces the cumulative surface runoff. Considering the IGRS can provide more hydrological benefits than the GRS under the same climate conditions, we may conclude that the widespread implementation of both the GRS and the IGRS in Nanchang and other densely developed cities in the MLRYR region could significantly reduce surface and peak runoff rates.


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