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2021 ◽  
Vol 58 ◽  
Author(s):  
Elle Rajandu ◽  
Tiina Elvisto ◽  
Hanna-Liisa Kappel ◽  
Marko Kaasik

Considering the recent growth of interest in using mosses in creating vegetated green roofs, we set the aim of our study to get an overview of the variety of moss and liverwort species and communities growing spontaneously on roofs. Data were collected from 67 roofs of five different types of materials: fibre cement, bitumen, stone, thatched and steel from Tallinn and rural areas on Hiiumaa Island and in South Estonia. Indicator species analysis, MRPP, cluster analysis and ordination methods (DCA, CCA) were used for data analysis. As a result of this research, generalist bryophytes occurring on all types of roofing materials were studied and bryophyte species characteristics for certain material types were identified. The thatched roofs differed most clearly from the other roof types in their species composition and had the highest species diversity. Stone and fibre cement roofs had similar species composition. The results revealed significant dependence of the composition of the bryophyte flora on roofs on the density of the bryophyte carpet formed over time on the roof and the presence of a tree canopy above the roof. Other important factors were roof relief, the height of the roof from the ground and the indicator of environmental pollution NOx. However, the studied roofs in Tallinn and rural areas did not show significant differences in the species composition of bryophytes. Five communities were delimited: (1) Syntrichia ruralis – Schistidium apocarpum; (2) Orthotrichum speciosum – Bryum argenteum; (3) Brachythecium rutabulum – Hypnum cupressiforme; (4) Ceratodon purpureus – Rhytidiadelphus squarrosus; and (5) Pleurozium schreberi – Dicranum scoparium. The mentioned communities inhabited locations that differed in environmental conditions. The findings of this research can help choose the roofing material and species suitable for a certain location in creating moss greenery on roofs.


2021 ◽  
Vol 232 (12) ◽  
Author(s):  
Anna Marszałek ◽  
Mariusz Dudziak

AbstractAs water resources become increasingly scarce, the concept of water reuse is gaining importance. Recently, attention has been paid to the use of rainwater as an alternative water resource. Part of this study, laboratory-scale experiments were conducted to evaluate the effectiveness and efficiency of the ultrafiltration process. The aim of the research was to assess the influence of pollutants from various roof coverings on the ultrafiltration process and the occurrence of membrane fouling. Additionally, the rainwater disinfection process was performed using UV radiation. Analysis of rainwater collected from various roofing materials, evaluating rainwater treatment by ultrafiltration in a cross-flow system, determination of the effectiveness and efficiency of the UF membrane, and additional disinfection of rainwater using UV radiation were carried out. Rainwater was collected from various roofing materials, such as steel roof tiles (RW1), bituminous shingles (RW2), and tar paper roofing (RW3). The treatment efficiency of ultrafiltration was evaluated by monitoring typical quality parameters: color, turbidity, COD, TOC, absorbance of UV254, ammonium, conductivity, and pH. Coliform bacteria, Escherichia coli and Enterococci, were monitored as total number of microorganisms at 22 ± 2 °C after 72 h. As expected, a significant reduction in individual parameters was recorded. COD of rainwater decreased in RW1 by 59%, in RW2 by 69%, and in RW3 by 74%. The ultrafiltration process ensured the complete retention of the coliform bacteria and E. coli. Complete elimination of microorganisms was demonstrated when the ultrafiltration process and UV radiation disinfection were combined.


2021 ◽  
Vol 13 (17) ◽  
pp. 9967
Author(s):  
Fadye Al Fayad ◽  
Wahid Maref ◽  
Mohamed M. Awad

This article performed a comprehensive review of the different state-of-the-art of roofing technologies and roofing materials and their impact on the urban heat island (UHI) and energy consumption of buildings. The building roofs are the main sources of undesirable heat for buildings, especially in warm climates. This paper discusses the use and application of white roofing material in emerging economies. The use of white roofing material is a suggestion because of its cooling, evaporative and efficiency characteristics compared to traditional black roofing materials. Many research studies have shown that the darker roofing surfaces that are prevalent in many urban areas actually can increase temperature by 1 to 3 degrees Celsius to the environment surrounding these urban areas. Additionally, improved temperature control and heat reflection also work to reduce the energy requirements for the interior spaces of the structures that have white roofing surfaces. The white or lighter colored roofs tend to reflect a part of the solar radiation that strikes the roof’s surface. Consequently, one might believe that white roofing material would be commonplace and especially so within emerging economies. Yet, this is hardly the case at all. This paper examines the issue of white roofing materials in emerging economies from a dual perspective. The dual perspective includes the technical details of white roofing material and its impact on lowering the interior temperature of the affected structures, which consequently reduces hours of indoor thermal discomfort and use of air conditioners in indoor spaces. The other element in this study, however, involves the marketing aspect of white roofing material. This includes its adoption, acceptance and cost-benefit in emerging economies.


2021 ◽  
Vol 410 ◽  
pp. 699-703
Author(s):  
Valeriya È. Shvarczkopf ◽  
Irina A. Pavlova ◽  
Elena P. Farafontova

The research focuses on the properties of by-products formed in the production of porcelain stoneware: polishing residue and residue of the mixture-preparation shop. The polishing residue consists of glassy phase (80%), quartz (14%), mullite (5%). Residue of the mixture-preparation shop consists of quartz (~ 18%), muscovite (~ 6.9%), kaolinite (~ 20.5%), calcium-sodium feldspar (~ 51.4%), diopside (~ 2.98%). Polishing residue occurs when polishing porcelain stoneware to create a glossy surface and when polishing the side faces of porcelain stoneware to obtain accurate tile geometry. The particle size of the polishing residue is less than 0.2 mm, and the residue of the mixture-preparation shop is less than 40 microns. Residue of the mixture-preparation shop is formed when cleaning equipment: mills, mixers, slipways, etc. The ways of utilization of by-product are follows: as a filler for the silicate production; for polymer-cement, water-dispersion and oil paints; as a filler for the production of roofing materials, bituminous roofing mastics based on organic binders; raw materials for the production of foam glass materials and products.


Author(s):  
A.M.A.M. Premathilaka ◽  
◽  
T.D.C. Pushpakumara ◽  

Increasing of population around the world has imposed considerable strains on the water resources. Hence, regulatory authorities have faced significant challenges to expand their water supply schemes not only due to financial constraints but also due to limited water resources. Consequently, there has been a growing interest, especially in developing countries, in harvested roof run off as an alternative source of drinking water. However, in determining the end use and the potential success of such an option, the possible problems associated with water quality need to be analyzed and the feasibility of using rainwater as a source of water for household use should be determined. Therefore, this research study was focus on evaluating roof runoff as a drinking water source in different urban land uses where different urban activities are present. For this purpose, a roof runoff samples were collected from three selected land uses namely industrial, commercial and residential. The samples have collected from each land use with three selected roofing materials which are common to the area. This is to evaluate the roof runoff quality based on the variability of land use pattern as well as the variability on roofing materials. All the collected samples have tested for a range of water quality parameters namely, pH, alkalinity, Hardness, Turbidity, TS, COD, Nitrogen (Ammonia), chloride and biological contaminations. Both uni-variate and stacked area analysis techniques were used in the analysis of test results. Based on the outcomes, recommendations are provided to use harvested roof runoff as a drinking water source in urban land uses in Sri Lanka. Keywords urban land uses; drinking water quality parameters; rainwater harvesting


Britannia ◽  
2021 ◽  
pp. 1-19
Author(s):  
Michael Fulford ◽  
Sara Machin

ABSTRACT Excavation of the Roman tilery at Little London, Pamber, Hampshire, has prompted a reassessment of the dating of relief-patterned tile, assigning the bulk of production to the Claudio-Neronian period rather than the late first to mid-/late second century. This material has been privileged for retention in excavation archives but can now be seen as a proxy for the manufacture of a much wider range of ceramic building material, typically discarded on site, which, in the case of products from Little London and pre-Flavian Minety (Wiltshire), travelled distances of up to 100 km. Redating implies more extensive public and private building in town and country south and east of the Fosse Way before the Flavian period than has previously been envisaged. While private building included the construction of bath-houses, heated rooms and the provision of roofing materials, public building, we suggest, provided tabernas et praetoria along the principal roads of the province. In the private sphere such building provides a possible context for Dio Cassius’ mention of the recall and confiscation of large loans made to Britons before the Boudican rebellion. Finally, consideration of fabric needs to be added to the criteria for retaining ceramic building material in excavation archives.


2021 ◽  
Vol 8 (02) ◽  
pp. 51-59
Author(s):  
Hasan Basri Arif Rahman ◽  
Mochamad Hasjim Bintoro ◽  
Supijatno Supijatno

Natural populations of sago (Metroxylon sagu) in Indonesia show morphological variations in its organs, particularly the leaves. The existing variations resulted in sago type names provided by the locals. The sago plant types include Mahang, Buntal, Salak, Madang and Gandut. Sago leaves are economically important in Indonesia, mainly because they provide a potentially profitable and environment-friendly source of house roofing materials. Determining leaf variation among sago plants would provide information for a better way of choosing which among the current accessions/varieties of sago has the best leaf quality and production. Leaf variations in sago were recorded in shape, size, and color. The aim of this study are a) to compare differences in leaf morphology among sago types obtained from different geographic areas, and b) to determine whether these different sago types correspond to certain sago plant grouping. The qualitative and quantitative analysis showed variations in leaf characteristics of sago trees. Additionally, this study shows that based on leaf variations, the sago of South Borneo Province can be separated into two groups. The first group is Mahang and Gandut, which have long rachis, leaflets and leaves, and largest leaf area. The second group composed of Buntal, Salak and Madang accessions, which have short rachis and leaves, and smallest leaf area. Other results showed that there were characters that contributed significantly to the diversity of sago plants in the study area including spines, white stripe or banding on the rachis and petiole length. In line with our results, Mahang and Gandut accessions are the best accessions to be cultivated in the area, because they have wider leaves which support higher rates of photosynthesis. Further study should be conducted on phylogenetic using DNA sequencing to confirm divisions of the two sago groups.    


Author(s):  
Numair Abdul Musawwir S. J

Our experimental investigation is being carried out to find out an alternative for tiles made from terracotta, because these tiles get easily cracked having less in strength. This drawback is likely motivated to conduct investigation to deliver the product by not this limitation. So, we have implemented work by using material called ‘pumice’. Naturally it will absorb the heat and emit cooling to the atmosphere. At early stage pumice powder were added in the range 2.5%, 5%, and 7.5%. Conventionally available materials do not offer acceptable solutions. Prices of corrugated G.I. sheets are continuously escalating, and their use in not preferred because of thermal discomfort. Use of cement sheets is not recommended because of health hazards associated with asbestos. In India there is an acute shortage of locally available cheap roofing materials. Home-builders particularly the poor, are in dire need of cost-effective materials to build their homes with. In addition, mass rural housing programmers supported by Central and State Governments are increasingly looking at low-cost building techniques.


2021 ◽  
Author(s):  
Rockford Boyer

Roof enclosures traditionally have the largest litigation potential in the construction industry due to the complexities in the design and application. Development of a self-drying roof enclosure would potentially minimize the litigation and provide the additional benefits of increased resiliency, reduced financial burden for building owners, and minimal impact on the environment. Past studies have shown that the self-drying roof enclosures are viable, however, they must meet several performance characteristics. Oak Ridge National Laboratory developed six characteristics required to obtain a functional self-drying roof enclosure. New roofing materials on the market allow for the effective drying potential of enclosures when they become wet. WUFI 6.1 6.1 hygrothermal models were developed to determine if the theory of self-drying roof enclosures is valid in all ASHRAE climatic zones. Effective theoretical self-drying roof enclosure designs are highlighted for potential effectiveness spanning all climatic zones in North America.


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