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Article
Publication date: 1 September 2017

Huanchun Huang, Yingxia Yun, Jiangang Xu, Shizhen Wang, Xin Zheng, Jing Fu and Lintong Bao

Urban water bodies play an important role in reducing summertime urban heat island (UHI) effects. Previous studies focused mainly on the impact of water bodies of large…

Abstract

Urban water bodies play an important role in reducing summertime urban heat island (UHI) effects. Previous studies focused mainly on the impact of water bodies of large areas, and there is no analysis of the efficacy and scale effect of how small and medium-sized water bodies reduce the UHI effects. Hence, these studies could not provide theoretical support for the scientific planning and design of urban water bodies. This study aims to confirm, within different scale ranges, the efficacy of a water body in reducing the summertime UHI effects. We propose a scale sensitivity method to investigate the temporal and spatial relationship between urban water bodies and UHI. Based on the scale theory and geostatistical analysis method in landscape ecology, this study used the platforms of 3S, MATLAB, and SPSS to analyze the distance-decay law of water bodies in reducing summertime UHI effects, as well as the scale response at different water surface ratios. The results show that the influence of water surfaces on UHIs gradually decreases with increasing distance, and the temperature rises by 0.78 °C for every 100 m away from the water body. During daytime, there is a scaled sensitivity of how much water surfaces reduce the summertime UHI effects. The most sensitive radius from the water was found at the core water surface ratio of 200 m. A reduction of UHI intensity by 2.3 °C was observed for every 10% increase of the average core water surface ratio. This study provides a theoretical reference to the control of heat islands for the planning and design of urban water bodies.

Details

Open House International, vol. 42 no. 3
Type: Research Article
ISSN: 0168-2601

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Article
Publication date: 1 June 1992

KAMEL M. AL‐KHALIL, THEO G. JR. KEITH and KENNETH J. DE WITT

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct…

Abstract

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct impingement, into individual rivulets. The wetness factor distribution resulting from the film breakup and rivulet configuration on the surface are predicted in the numerical solution procedure. The solid wall is modelled as a multi‐layer structure and the anti‐icing system used is of the thermal type utilizing hot air and/or electrical heating elements embedded within the layers. Details of the calculation procedure and the methods used are presented.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 2 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 July 2000

Chieko Umetsu and Ujjayant Chakravorty

Suggests a spatial conjunctive use model of an irrigation project in which the utility invest optimally for the water distribution system and charge farmers the shadow…

Abstract

Suggests a spatial conjunctive use model of an irrigation project in which the utility invest optimally for the water distribution system and charge farmers the shadow price of surface and groundwater. Seepage from the irrigation canal and on the field are assumed to recharge the groundwater aquifer. Particular attention was given to the effects of conveyance on the allocation of both surface and groundwater resources and the distribution of rents. An empirical model indicated that higher conveyance costs skew the distribution of water as well as rents over the project area. This suggests that the tail farmers need to face a substantially higher price for water if the system deteriorates and conveyance costs increase in the long run.

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International Journal of Social Economics, vol. 27 no. 7/8/9/10
Type: Research Article
ISSN: 0306-8293

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Article
Publication date: 26 August 2014

H.G. Rábade, P. Vellando, F. Padilla and R. Juncosa

A new coupled finite element model has been developed for the joint resolution of both the shallow water equations, that governs the free surface flow, and the groundwater…

Abstract

Purpose

A new coupled finite element model has been developed for the joint resolution of both the shallow water equations, that governs the free surface flow, and the groundwater flow equation that governs the motion of water through a porous media. The paper aims to discuss these issues.

Design/methodology/approach

The model is based upon two different modules (surface and ground water) previously developed by the authors, that have been validated separately.

Findings

The newly developed software allows for the assessment of the fluid flow in natural watersheds taking into account both the surface and the underground flow in the way it really takes place in nature.

Originality/value

The main achievement of this work has dealt with the coupling of both models, allowing for a proper moving interface treatment that simulates the actual interaction that takes place between surface and groundwater in natural watersheds.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 9 August 2011

F.M. Adebiyi and O.I. Asubiojo

– This paper aims to examine the quality of the surface waters of the bitumen deposit area of Nigeria and also to establish the relationship between the deposit and the waters.

Abstract

Purpose

This paper aims to examine the quality of the surface waters of the bitumen deposit area of Nigeria and also to establish the relationship between the deposit and the waters.

Design/methodology/approach

Physico-chemical parameters were measured using standard analytical procedures, while the elemental contents were determined using total reflection X-ray fluorescence spectroscopy. Data acquired were interpreted using statistical techniques – charts, t-test, pollution index (PI) and cross-plot analysis.

Findings

A river located close to the bitumen well contained the highest concentrations of metals that are known to be associated with hydrocarbon formation. Comparison of the levels of the analyzed parameters in the waters with their standard permissible limits showed that the levels of Cl−, SO42-, total alkalinity and Cr, Mn, Fe, Ni, Cu, Zn and Pb in the river very close to the capped bitumen well and big rivers were high and low in the small streams. This was corroborated by their pollution index values. Results of the cross-plot analysis of the waters-river close to bitumen well/bitumen (R2=0.5); small streams/bitumen (R2=0.8) and big rivers/bitumen (R2=0.2) showed moderate; strong and weak positive correlations respectively, suggesting moderate, strong and weak inter-element correlations respectively between the sets of waters and the Nigerian bitumen deposit, and also establishing relationships between the deposit and the surface waters.

Originality/value

The paper provides insight into the potability of the waters; establishment of the inter-element relationship between the bitumen deposit and the waters. These results can serve as a fingerprint for bitumen exploration elsewhere and for similar mineral deposit settings.

Details

Management of Environmental Quality: An International Journal, vol. 22 no. 5
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 24 February 2012

Kirsti Korkka‐Niemi, Anna‐Liisa Kivimäki, Kirsti Lahti, Maria Nygård, Anne Rautio, Veli‐Pekka Salonen and Petri Pellikka

The purpose of this paper is to emphasize the importance of groundwater‐surface water interaction when studying, modeling and assessing climate change impacts on river…

Abstract

Purpose

The purpose of this paper is to emphasize the importance of groundwater‐surface water interaction when studying, modeling and assessing climate change impacts on river water management.

Design/methodology/approach

The investigations were focused on River Vantaa and its tributaries in southern Finland. The main methods used involved aerial infrared photography, thermal profiling of river sediments, water quality measurements, isotopic composition of oxygen and hydrogen δ18O, δ2H and river water temperature measurements. The authors present the first results of the field measurements targeted to identify the groundwater recharge and discharge zones within the river system.

Findings

Groundwater discharge zones were found to have a significant impact on water quality and volume in River Vantaa and its tributaries. In the drainage basin, the aerial infrared photography seemed to be a feasible and cost‐effective method to identify areas of groundwater discharge across the entire river basin. Around 350 groundwater/surface water interaction sites along the 220 km river system could be identified.

Practical implications

The interaction sites identified during the season of low flow rate should be considered as potential risk areas because during flood periods groundwater quality might be at risk due to bank infiltration. This should be considered in river basin management within predicted changing climatic conditions.

Originality/value

This is the first attempt in Finland to map systematically groundwater and river water interactions. The focus of the paper is relevant, because according to the existing climate scenarios, flooding of the main rivers in Finland will be more frequent in future, increasing the probability of groundwater‐surface water interaction.

Details

Management of Environmental Quality: An International Journal, vol. 23 no. 2
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 14 December 2020

Alia Al-Ghosoun, Ashraf S. Osman and Mohammed Seaid

The purpose of this study is twofold: first, to derive a consistent model free-surface runup flow problems over deformable beds. The authors couple the nonlinear…

Abstract

Purpose

The purpose of this study is twofold: first, to derive a consistent model free-surface runup flow problems over deformable beds. The authors couple the nonlinear one-dimensional shallow water equations, including friction terms for the water free-surface and the two-dimensional second-order solid elastostatic equations for the bed deformation. Second, to develop a robust hybrid finite element/finite volume method for solving free-surface runup flow problems over deformable beds. The authors combine the finite volume for free-surface flows and the finite element method for bed elasticity.

Design/methodology/approach

The authors propose a new model for wave runup by static deformation on seabeds. The model consists of the depth-averaged shallow water system for the water free-surface coupled to the second-order elastostatic formulation for the bed deformation. At the interface between the water flow and the seabed, transfer conditions are implemented. Here, hydrostatic pressure and friction forces are considered for the elastostatic equations, whereas bathymetric forces are accounted for in the shallow water equations. As numerical solvers, the authors propose a well-balanced finite volume method for the flow system and a stabilized finite element method for elastostatics.

Findings

The developed coupled depth-averaged shallow water system and second-order solid elastostatic system is well suited for modeling wave runup by deformation on seabeds. The derived coupling conditions at the interface between the water flow and the bed topography resolve well the condition transfer between the two systems. The proposed hybrid finite volume element method is accurate and efficient for this class of models. The novel technique used for wet/dry treatment accurately captures the moving fronts in the computational domain without generating nonphysical oscillations. The presented numerical results demonstrate the high performance of the proposed methods.

Originality/value

Enhancing modeling and computations for wave runup problems is at an early stage in the literature, and it is a new and exciting area of research. To the best of our knowledge, solving wave runup problems by static deformation on seabeds using a hybrid finite volume element method is presented for the first time. The results of this research study, and the research methodologies, will have an important influence on a range of other scientists carrying out research in related fields.

Details

Engineering Computations, vol. 38 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 10 August 2018

Minghua Pang, Xiaojun Liu and Kun Liu

This study aims to clarify the influence mechanism of surface texture (arrays of circular/square and concave/convex) on the frictional properties of WC-TiC/Co cemented…

Abstract

Purpose

This study aims to clarify the influence mechanism of surface texture (arrays of circular/square and concave/convex) on the frictional properties of WC-TiC/Co cemented carbide under a water-miscible cutting fluid (JAEGER SW-105, 5 per cent) environment.

Design/methodology/approach

Four types of textured cemented carbide surfaces (arrays of circular/square and concave/convex that have different textured densities and sizes) were fabricated using laser surface technology. Pin-on-disc tests between an AISI 304 stainless steel ball and WC-TiC/Co cemented carbide samples were carried out for a variety of normal loads (1, 3 and 5 N) under a water-miscible cutting fluid environment. The effects of textured type, density and size on the friction coefficient were obtained.

Findings

Compared to a smooth surface, some textured samples successfully resulted in a reduced friction coefficient. The friction coefficient of textured WC-TiC/Co cemented carbide samples depended greatly on the textured type, density and size. Given the increase in textured density (ranging from 10 to 30 per cent), the friction coefficient of the test samples first decreased and then increased for all normal loads (1, 3 and 5 N), and the minimum friction coefficient was obtained at the textured density of 20 per cent. The concave textured surface showed obvious advantages in friction coefficient reduction regardless of textured density, size and normal load compared with the convex textured surface. Finally, the correlation between textured diameter/length and Hertzian contact width was studied for various normal loads and texture sizes. A 2.6 ratio of textured diameter/length to Hertzian contact width is recommended under for lubricated sliding contact with the water-miscible cutting fluid.

Originality/value

The main contribution of this work is in providing a design reference and obtaining an essential understanding on the effect of surface texture (arrays of circular/square and concave/convex) on the friction of WC-TiC/Co cemented carbide under a water-miscible cutting fluid environment.

Details

Industrial Lubrication and Tribology, vol. 70 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 March 2017

Qu Jun-e, Chen Geng, Wang Hai-ren and Cao Zhi-yong

The purpose of this paper is to investigate the effect of water content of assembly solution on the adsorption behavior and corrosion protection performance of…

Abstract

Purpose

The purpose of this paper is to investigate the effect of water content of assembly solution on the adsorption behavior and corrosion protection performance of 1–tetradecylphosphonic acid [TDPA, CH3(CH2)13P(O)(OH)2] films on aluminum alloy surface in NaCl solution.

Design/methodology/approach

Self-assembled monolayers (SAMs) of TDPA were prepared on the 2024 aluminum alloy surface in TDPA containing ethanol-water solutions with different water contents. The adsorption behavior of the SAMs on the alloy surface and their corrosion protection properties in a 3.5 per cent NaCl solution were characterized by potentiodynamic polarization scan, Fourier-transformed infrared spectroscopy (FTIR) and atomic force microscopy (AFM).

Findings

The FTIR results demonstrated that the TDPA molecules were successfully adsorbed on the 2024 aluminum alloy surface, and the density of the SAMs increased with the increasing water content in the assembly solution. The electrochemical studies and corrosion morphologies observed by AFM showed that the optimal condition is 2 h of assembling in solution B or solution C. The corrosion inhibition efficiency values follow the order solution B ≈ solution C > solution A at the first 2 h assembly and solution B > solution C > solution A while the assembly time exceeded 2 h. The dependence of corrosion inhibition performance of the SAM on the water content and on the assembly time is related to the balancing of competition between TDPA adsorption and dissolution of the alloy oxidation film.

Originality/value

It illustrates potential application prospects of TDPA for surface treatment of aluminum alloy. Via the comparison with our previous work, this paper provides useful information regarding the difference of corrosion inhibition properties of organic phosphonic acid for aluminum alloy between in neutral and in acid solution.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Open Access
Article
Publication date: 18 June 2021

Ishita Afreen Ahmed, Shahfahad Shahfahad, Mirza Razi Imam Baig, Swapan Talukdar, Md Sarfaraz Asgher, Tariq Mahmood Usmani, Shakeel Ahmed and Atiqur Rahman

Deepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the south-western part of Guwahati, Assam. With urban development at its forefront…

Abstract

Purpose

Deepor Beel is one of the Ramsar Site and a wetland of great biodiversity, situated in the south-western part of Guwahati, Assam. With urban development at its forefront city of Guwahati, Deepor Beel is under constant threat. The study aims to calculate the lake water volume from the water surface area and the underwater terrain data using a triangulated irregular network (TIN) volume model.

Design/methodology/approach

The lake water surface boundaries for each year were combined with field-observed water level data to generate a description of the underwater terrain. Time series LANDSAT images of 2001, 2011 and 2019 were used to extract the modified normalized difference water index (MNDWI) in GIS domain.

Findings

The MNDWI was 0.462 in 2001 which reduced to 0.240 in 2019. This shows that the lake water storage capacity shrank in the last 2 decades. This leads to a major problem, i.e. the storage capacity of the lake has been declining gradually from 20.95 million m3 in 2001 to 16.73 million m3 in 2011 and further declined to 15.35 million m3 in 2019. The fast decline in lake water volume is a serious concern in the age of rapid urbanization of big cities like Guwahati.

Originality/value

None of the studies have been done previously to analyze the decline in the volume of Deepor Beel lake. Therefore, this study will provide useful insights in the water resource management and the conservation of Deepor Beel lake.

Details

Frontiers in Engineering and Built Environment, vol. 1 no. 1
Type: Research Article
ISSN: 2634-2499

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