scholarly journals THE USE OF PHOTOCATALYTIC CONCRETES IN ROAD CONSTRUCTION

2021 ◽  
Vol 6 (12) ◽  
pp. 16-26
Author(s):  
N. Shestakov ◽  
D. Alekseeva ◽  
D. Polosina
Keyword(s):  
Titanium Dioxide ◽  
Nitrogen Oxides ◽  
Water Absorption ◽  
Aqueous Medium ◽  
Road Construction ◽  
Cellulose Fibers ◽  
Environmental Load ◽  
Mathematical Planning ◽  
Photocatalytic Reactions ◽  
The City

The article discusses the possibility of reducing the atmospheric environmental load of highways by applying compositions with photocatalytic properties to acoustic screens. It is found that the amount of nitrogen oxides on the territory of the city of Moscow exceeds the MPC norms. Therefore, a potential way to reduce the level of the average daily and maximum one-time MPC of nitrogen oxides is proposed, when using coatings of traditional acoustic screens with photocatalytic compositions. Titanium dioxide in anatase form is considered as a photocatalytic agent. To reduce the density and increase the porosity of cement compositions, a cellulosic suspension obtained by saturation in an aqueous medium with subsequent homogenization is introduced. The effect of cellulose in the considered cement systems in combination with a photocatalytic agent has been investigated. By the method of mathematical planning, a two-factor compositional experiment is compiled. In result, the degrees of influence of titanium dioxide and cellulose additives on the strength, density and water absorption of the composites under study are established. The study of the structure of the obtained composites shows that TiO2 is mainly located on the surface of cellulose fibers, which theoretically increases the useful surface for photocatalytic reactions and, as a consequence, the final efficiency of the compositions.

scholarly journals Urban influence on the concentration and composition of submicron particulate matter in central Amazonia

2018 ◽  
Author(s):  
Suzane S. de Sá ◽  
Brett B. Palm ◽  
Pedro Campuzano-Jost ◽  
Douglas A. Day ◽  
Weiwei Hu ◽  
...  
Keyword(s):  
Time Series ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Mass Concentration ◽  
Critical Role ◽  
Metropolitan Region ◽  
Anthropogenic Emissions ◽  
Organic Mass ◽  
The City

Abstract. Fundamental to quantifying the influence of human activities on climate and air quality is an understanding of how anthropogenic emissions affect the concentrations and composition of airborne particulate matter (PM). The central Amazon basin, especially around the city of Manaus, Brazil, has experienced rapid changes in the past decades due to ongoing urbanization. Herein, changes in the concentration and composition of submicron PM due to pollution downwind of the Manaus metropolitan region are reported as part of the GoAmazon2014/5 experiment. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a suite of other gas- and particle-phase instruments were deployed at the T3 research site, 70 km downwind of Manaus, during the wet season. At this site, organic components represented on average 79 ± 7 % of the non-refractory PM1 mass concentration, which was in the same range as several upwind sites. The organic PM1 was, however, considerably more oxidized at T3 compared to upwind measurements. Positive-matrix factorization (PMF) was applied to the time series of organic mass spectra collected at the T3 site, yielding three factors representing secondary processes (73 ± 15 % of total organic mass concentration) and three factors representing primary anthropogenic emissions (27 ± 15 %). Fuzzy c-means clustering (FCM) was applied to the afternoon time series of concentrations of NOy, ozone, total particle number, black carbon, and sulfate. Four clusters were identified and characterized by distinct airmass origins and particle compositions. Two clusters, Bkgd-1 and Bkgd-2, were associated with background conditions. Bkgd-1 appeared to represent near-field atmospheric PM production and oxidation of a day or less. Bkgd-2 appeared to represent material transported and oxidized for two or more days, often with out-of-basin contributions. Two other clusters, Pol-1 and Pol-2, represented the Manaus influence, one apparently associated with the northern region of Manaus and the other with the southern region of the city. A composite of the PMF and FCM analyses provided insights into the anthropogenic effects on PM concentration and composition. The increase in mass concentration of submicron PM ranged from 25 % to 200 % under polluted compared to background conditions, including contributions from both primary and secondary PM. Furthermore, a comparison of PMF factor loadings for different clusters suggested a shift in the pathways of PM production under polluted conditions. Nitrogen oxides may have played a critical role in these shifts. Increased concentrations of nitrogen oxides can shift pathways of PM production from HO2-dominant to NO-dominant as well as increase the concentrations of oxidants in the atmosphere. Consequently, the oxidation of biogenic and anthropogenic precursor gases as well as the oxidative processing of pre-existing atmospheric PM can be accelerated. The combined set of results demonstrates the susceptibility of atmospheric chemistry, air quality, and associated climate forcing to anthropogenic perturbations over tropical forests.

scholarly journals The Construction Development Map of Magelang City

2021 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
Indah Khalimatul Lestari ◽  
Rian Destiningsih
Keyword(s):  
Regional Development ◽  
Road Construction ◽  
Economic Benefits ◽  
Construction Sector ◽  
Employment Services ◽  
Service Company ◽  
Goods And Services ◽  
Qualitative Descriptive ◽  
Local Construction ◽  
The City

The existence of construction in an area will have an influence on regional development. Likewise in the City of Magelang, the construction sector is a sector that contributes a fairly large GRDP with the construction of construction such as buildings and roads as the provision of facilities and infrastructure will result in an increase in community welfare which will also affect economic growth. The purpose of this study was identif construction sector in the form of roads and buildings with the results of a map of the distribution of construction in the City of Magelang by looking at the local construction service company so that it can be a reference in improving regional development, especially the construction sector to realize adequate infrastructure. As well as the socio-economic benefits of having a construction service company in Magelang City. This study used qualitative descriptive method with questionnaire, interview, observation and observation techniques. In the 2020 construction distribution map, there are high, medium and low building densities where high building densities dominate in the middle of the city along the main road. Road construction helps the distribution of goods and services and maximizes community access. The existence of a local construction service company provides benefits to the community both socially and economically, such as employment, services, and improvement of infrastructure facilities for the community. However, stronger synergy is needed to realize quality construction and utilize local resources in its implementation.

Efficient Eco-friendly Composite Fluorine Anhydrite-Based Materials

2017 ◽  
Author(s):  
Grigory Yakovlev ◽  
Jadvyga Keriene ◽  
Anastasiia Gordina ◽  
Irina Polyanskikh ◽  
Milan Bekmansurov
Keyword(s):  
Water Absorption ◽  
Lightweight Concrete ◽  
Gas Permeability ◽  
Average Density ◽  
Expanded Polystyrene ◽  
Environmental Load ◽  
Great Demand ◽  
Technogenic Waste ◽  
And Performance ◽  
Reduced Water

The paper presents possible ways of utilizing technogenic waste – fluorine anhydrite – by its use in production of dry mortars and piece goods from lightweight concrete with expanded polystyrene, as a organic filler, for low-rise construc-tion. The developed dry mortars are based on fluorine anhydrite binder and complex modifier comprising curing activator (sulfate or alkaline) and finely dispersed additive. The fluorine anhydrite-based compositions have improved physical and performance characteristics, including the improved strength and average density and reduced water absorption compared to the control composition. The developed lightweight anhydrite polystyrene concrete has the density grade of 700 kg/m3 and good vapor and gas permeability. The concrete is stabile while using and fire safe, because each granule of expanded poly-styrene is coated with anhydrite matrix, and has the strength sufficient for structural and heat insulating slabs and blocks. All mentioned compositions are eco-friendly and are in great demand for low-rise construction. Therefore the manufacturing of these compositions will consume a large amount of technogenic waste and will reduce the environmental load on the region where the waste is located.

Subsidence and Flooding in Bangkok

2005 ◽  
Author(s):  
Noppadol Phienwej ◽  
Prinya Nutalaya
Keyword(s):  
Land Subsidence ◽  
Flood Risk ◽  
Land Surface ◽  
Road Construction ◽  
Central Plains ◽  
Central Plain ◽  
The North ◽  
Chao Phraya River ◽  
The 1960S ◽  
The City

Bangkok, the capital of Thailand, is situated on flat, low land in the southern part of the Central Plain, one of the main physical units of the country. Through the heart of the city, the Chao Phraya flows from the north and discharges into the Gulf of Thailand, 25 km south of the city centre. The city was founded in 1782, and in its early years numerous klongs (canals) were dug for transportation and defence uses. These canals became corridors of early development, and banks were lined with houses, shop-houses, and temples, etc. With the beauty of its waterway landscape, Bangkok was once dubbed the Venice of the East. Unfortunately, such a resemblance no longer exists as most of the canals have been backfilled to make room for road construction in recent urbanization. The Bangkok metropolis, which at present has a population in excess of 10 million, has expanded rapidly on both banks of the river since 1950. It has encroached into surrounding provinces, covering an area of approximately 60 × 70 km. Owing to its flat topography and close proximity to the sea, flooding threatens the city annually. Modern urbanization has resulted in the drastic destruction or blockage of natural drainage paths, increasing the flood risk to the city. Severe land subsidence from excessive groundwater extraction since the 1960s has intensified the flood risk, as well as creating numerous foundation problems. At present the land surface in some areas is already below mean sea level. The city now has to rely on a flood protection system to prevent inundation. However, its effectiveness is only temporary because land subsidence has not yet ceased. The Central Plain is formed by the Chao Phraya River, the largest in the country. The river basin stretches from the Northern Highland to the Central Plain and covers about one-third of the country (514 000 km2). The Central Plain can be divided into the Upper and Lower Central Plains. The former extends from Tak to Nakhon Sawan Provinces. Four main rivers, namely, the Ping, the Wang, the Yom, and the Nan, which originate in the Northern Highland, traverse the plain and join together at Nakhon Sawan, 240 km north of Bangkok, to form the Chao Phraya River.

Lokalisierung und Adressierung als Verfahren erinnerungskultureller „Raumzuschnitte“ in Kommunikationsangeboten zur Stadtgeschichte

2019 ◽  
Vol 70 (1) ◽  
pp. 105-138
Author(s):  
Nicole M. Wilk
Keyword(s):  
Urban Development ◽  
Conversation Analysis ◽  
Urban Space ◽  
Basic Concept ◽  
Road Construction ◽  
Linguistic Description ◽  
Multimodal Text ◽  
The City ◽  
Media Formats ◽  
Linguistic Means

Abstract This article deals with new locative and multimodial media formats, which yield aspects of city histories, re-evaluating their cultural and also their touristic image. The analysis explores the shift from written city guides and building inscriptions to multimodal products (websites, apps) by focussing on two central techniques: the various forms of adressing and the linguistic description for localization, specifically local deicitica. Analogical to the “recipient design” as a basic concept of conversation analysis, the term “spacial design” is chosen to describe the linguistic means, which adjust the multimodal text to the artifacts of urban space, so that a interpretative historic formation will attach to the spacial environment and change the city view. One result of the analysis was the discovery of a mixture of personal and impersonal types of adressing, which shows, that personal adressing joins methods of multiple adressing in multimodal urban communication. The analysis also suggests, that localization practices get diversificated. The new communication products show multiple (“overdetermines”) deictica and phoric anchorages in the urban space, i. e. the deixis is overdetermined as perceptual and imagination-oriented, furthermore deictica are also connected with text elements (by phoric relations). As a discourse grammatical result, the emerged patterns construct an image of nearly automatical unevitaly and depersonalized urban development (e. g. road construction). This impression results from accounts of passive constructions related with instrumental sub-clauses.

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