Civil Engineering

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Shiv Nadar University

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(SoE) School of Engineering

Sustainable Water Resources Management

Optimal Use of Irrigation Water

The extreme rainfall event during June 2013 in the Western Himalayas caused widespread flash floods, which triggered landslides, a lake-outburst, and debris flow. For the hydrological study of such an unexpected extreme event, it is essential to have reliable and accurate rainfall predictions based on satellite observations. The mountainous state of Uttarakhand is covered by complex topography, and this state has few, unevenly distributed, rain gauge networks. This unique study was conducted to evaluate three satellite based rainfall products (i.e., TMPA-3B42, Global Satellite Mapping of Precipitation (GSMaP), and NOAA CPC Morphing Technique (CMORPH)) against the observed rain gauge-based India Meteorological Department (IMD) gridded dataset for this rainfall episode. The results from this comprehensive study confirmed that the magnitude of precipitation and peak rainfall intensity were underestimated in TMPA-3B42 and CMORPH against gauge-based IMD data, while GSMaP showed dual trends with under- and over-predictions. From the results of the statistical approach on the determination of error statistic metrics (MAE (mean absolute error), NRMSE (normalized root mean square error), PBIAS (percent bias), and NSE (Nash-Sutcliffe efficiency)) of respective satellite products, it was revealed that TMPA-3B42 predictions were more relevant and accurate compared to predictions from the other two satellite products for this major event. The TMPA-3B42-based rainfall was negatively biased by 18\%. Despite these caveats, this study concludes that TMPA-3B42 rainfall was useful for monitoring extreme rainfall event in the region, where rain-gauges are sparse. © 2017 by the authors.

Fulltext

Hydrology

Evaluation of satellite-derived rainfall estimates for an extreme rainfall event over Uttarakhand, Western Himalayas

<p>To investigate the seasonal and spatial variations of ion chemistry of fine particles in Northern Zhejiang Province (NZP), China, one year-long field sampling was conducted at four representative sites (two urban, one suburb, and one rural sites) in both cities of Hangzhou and Ningbo from December 2014 to November 2015. Twelve water soluble inorganic ions (WSII) were characterized in this comprehensive study. The annual average of PM2.5 concentration in NZP as overall was 66.2&nbsp;±&nbsp;37.7&nbsp;μg&nbsp;m−3, and urban sites in NZP were observed with more severe PM2.5 pollution than the suburban and rural sites. The annual average concentration of total WSII at four sampling sites in NZP was 29.1&nbsp;±&nbsp;19.9&nbsp;μg&nbsp;m−3, dominated by SO4 2− (10.3&nbsp;μg&nbsp;m−3), and followed by NO3 − (8.9&nbsp;μg&nbsp;m−3), NH4 + (6.6&nbsp;μg&nbsp;m−3), Cl− (1.3&nbsp;μg&nbsp;m−3) and K+ (0.7&nbsp;μg&nbsp;m−3). Among all cations, NH4 + was the predominant neutralizing ion with the highest neutralization factor (NF), while the remaining cations showed limited neutralization capacity. The highest and lowest sulfur oxidation ratio (SOR) values in this region were found in summer and winter, respectively; while the seasonal patterns for nitrogen oxidation ratio (NOR) were opposite to that of SOR. Principal component analysis (PCA) showed that the significant sources of WSII in NZP were industrial emissions, biomass burning, and formation of secondary inorganic aerosols. In addition, contribution from transboundary transport of polluted aerosols was also confirmed from the assessment through air mass backward trajectory analysis. © 2017 Elsevier Ltd</p>

Chemosphere

Temporal and spatial variation in major ion chemistry and source identification of secondary inorganic aerosols in Northern Zhejiang Province, China

Rotating biological filter (RBF), which provides higher oxygen mass transfer has been developed for treating gaseous volatile organic compounds (VOCs) such as BTEX (Benzene, toluene, ethylbenzene and xylene) at higher concentrations. The screening of enriched cultures has been done initially to enhance the performance of RBF for treating xylene, toluene and xylene, and BTEX at various loading rates. The removal efficiency of BTEX was maximum (82%), higher than toluene and xylene (79%), and xylene (72%). The presence of xylene enhanced the removal of toluene in the mixture. In the BTEX, toluene was found to be highly biodegradable followed by ethylbenzene, benzene and xylene. The RBF also removed nutrients from wastewater along with VOCs. The stability study of RBF showed that supply of nutrient media influenced the RBF performance more. Further, the predominant strain identified in the mixed culture was Enterobacter cloacae SP4001, responsible for biodegradation of BTEX. © 2017 Elsevier Ltd

Bioresource Technology

Treatment of gaseous volatile organic compounds using a rotating biological filter

{\textcopyright} 2017 American Society of Civil Engineers. Hydrological processes such as evaporation and evapotranspiration (ET) are affected by air humidity. Air humidity is commonly expressed as relative humidity (RH) or dew point temperature (Tdew) and is required for the determination of evaporation from water or soil surfaces and ET from cropped areas. However, the availability of humidity data is sometimes an issue. In cases in which RH data are not available, air humidity on a daily basis can be estimated by using daily maximum and minimum temperatures along with the dew point temperature. Guidelines from an international organization recommend the use of a dew point temperature slightly less than the daily minimum temperature for daily computations, when its measurements are not available. In this study, the daily average dew point temperature (Tdewmean) was taken as k°C less than the daily minimum temperature. Thus, daily RH data (maximum, minimum and mean RH) were generated from daily maximum and minimum temperatures for Roorkee Station (India) during 2012-2016. Four different values of k (k = 0, 1, 2, 3) were used for determining the actual vapor pressure values used in RH estimation. Daily RH values determined using different values of k were compared with observed RH data. It was observed that for the nonsummer months, having an average value of daily mean RH greater than 60% (January-March and July-December), k = 0 resulted in minimum error in RH estimation. However, during the summer months, having an average value of daily mean RH less than 60% (April-June), k = 3 provided relatively better estimates of RH. During the summer months, large errors occurred in the estimation of maximum and minimum RH values using this approach; hence, mean RH values that are relatively better estimated during these periods should be used for hydrological applications. Further, linear Tdew-RH relationships (with and without parabolic correction) have been assessed to determine daily Tdewmeanvalues. These relationships have been found to provide more accurate estimates of Tdewmean and actual vapor pressure on a daily basis than the FAO-56 vapor pressure models when only daily RHmean data are available (instead of RHmax and RHmindata) along with daily temperature data.

Journal of Irrigation and Drainage Engineering

Estimation of Relative Humidity and Dew Point Temperature Using Limited Meteorological Data

Deterioration of concrete due to sulphate attack is a major durability problem for concrete structures exposed to sulphate-rich soil and groundwater such as septic tanks, sewage pipes and water treatment plants. The continuous exposure to a sulphate-rich environment, concrete loses its strength and durability resulting in a reduction of the designed service life. The widespread occurrence of sulphate attack and the destruction caused by it have attracted researchers over the years into the study of the deterioration mechanism and methods to combat it. This paper deals with the monitoring of deterioration in concrete for accelerated sulphate environment and detecting damage using half-cell potential method, powder X-Ray diffraction and acid penetration test. The accelerated testing adopted here provides a realistic approach for predicting the deterioration of concrete under Sulphur attack. The paper demonstrates the various stages of changes occurred in cement composite during exposed environment and successfully monitored through conventional NDT Techniques. The results give in depth understanding microstructural behaviour of concrete elements during chemical attack. © 2017 Taylor & Francis Group, London.

Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure - 5th International Symposium on Life-Cycle Engineering, IALCCE 2016

Monitoring and detection of damage in cement composite under sulphate attack

Benzene is one of hazardous pollutants generated from paint, chemical, and petrochemical industries have a harmful impact on human health and the atmosphere. This study reports benzene biodegradation by indigenous mixed microbial culture in shake flasks over a concentration ranging from 25 to 600 mg/l, and the kinetics involved in the process has been modeled. Experimental data obtained were fitted to both inhibition and noninhibition models to determine the biokinetic constants. Haldane model was best to predict the experimental data. The central composite design was further used for optimization of pH and benzene concentration to enhance the benzene biodegradation. At an optimum pH of 7.05 and benzene concentration of 332.82 mg/l, the maximum estimated specific growth rate and degradation rate were 0.05 1/h and 6.01 mg/l h, respectively. The LC-MS analysis of sample indicate the presence of catechol, cis-1,2-dihydrobenzene-1,2-diol, and 2-hydroxymuconate semialdehyde as intermediates, which justifies the developed pathway of benzene biodegradation. The predominant microorganism in the mixed culture responsible for benzene degradation was later identified to be Enterobacter cloacae SG208. The results provide insight into the process of benzene biodegradation and prove the potential of indigenous mixed culture for treatment of benzene. © 2016 Elsevier Ltd

International Biodeterioration and Biodegradation

Benzene biodegradation by indigenous mixed microbial culture: Kinetic modeling and process optimization

Integration of information, communication and materials technologies into the electricity Smart Grids is the key to sustainable clean energy future. This study focuses on materials innovation and design of power transmission lines. Conventional bi-material power transmission lines consist of aluminum conductors with steel reinforcement. Increase in temperature of transmission lines due to Joule heating limits their current carrying capacity and the efficiency of power transmission. New design of transmission wires proposed in this study consists of carbon nanostructure (CNS)-epoxy composites in a multilayered architecture to enable multifunctional capabilities. Excellent thermal transport properties of CNS-epoxy composites are utilized to optimally dissipate heat from the outer surface of transmission wire in order to maximize its performance. A coupled electrical-thermal finite element (FE) analysis of Aluminum Conductor Steel Reinforced (ACSR) wires is performed and the results are benchmarked with those obtained from relevant IEEE standards. The validated model is then extended to new transmission line composed of aluminum conductor - composite core with CNS-epoxy composite coating (ACCC-CNS). Steady-state coupled FE analyses of ACSR and ACCC-CNS wires indicate that the proposed design of ACCC-CNS wire enables transmission of larger currents than an equivalent ACSR wire for the same amount of conductor material due to reduced operating temperature. The proposed design of power lines would enable development of Smart Grids for more efficient utilization of electricity from renewable sources.

Journal of Cleaner Production

High performance overhead power lines with carbon nanostructures for transmission and distribution of electricity from renewable sources

Megacities in India (population more than 10 million) have taken actions to control air-pollution emissions. However, the second-level cities (population between one and 10 million) have not drawn an action plan, and people face serious air pollution in these cities. For one such city, Lucknow, a geographic information system (GIS)-based methodology for emission inventory of on-road vehicles has been developed. The pollutants include: sulfur dioxide (SO2); oxides of nitrogen (NOx); carbon monoxide (CO); particulate matter (PM); 1,3 butadiene; formaldehyde; acetaldehyde; total aldehydes; and total polycyclic aromatic hydrocarbons (PAHs). Video recording was done at nine road intersections of varying land-use patterns to assess traffic count and vehicle kilometer travel. Parking lot surveys were carried out for assessing engine type, vehicle age, etc. and to arrive at a suitable net emission factor for each vehicle category. The 2-wheelers (2-Ws) and 4-wheelers (4-Ws) dominate the total traffic with an 83% share and are main sources of NOx (46%) and CO (77%). The heavy duty vehicles (HDVs: buses and trucks), although they account for only 2% of the vehicle fleet, emit disproportionately high emissions (23% of SO2, 36% of NOx, and 28% of PM). Spatial cell (2×2 km)-wise emission inventory of pollutants indicates that the city center has the highest pollutant emissions resulting from a large number of vehicles, mostly 2-Ws, 3-Ws, and passenger cars. The inventory information can be used for short-term and long-term planning to reduce emissions. © 2014 American Society of Civil Engineers.

Journal of Hazardous, Toxic, and Radioactive Waste

GIS-based on-road vehicular emission inventory for Lucknow, India

Compression response of fine grained soils is generally modeled by bilinear relationship between void ratio (e) and logarithmic of effective stress (σ'). In general, compression curve of overconsolidated soil is nonlinear in nature as it varies smoothly from linear portion of initial part of the curve to the linear portion of the later part of the curve. The bilinear model is unable to represent the smooth transition of the compression curve. As a result, it leads to an overestimation of the settlement and introduces a kink in the predicted stress-strain relationship of overconsolidated soil from the elasto-plasticity model wherein it is used as a component defining volumetric hardening. The present paper proposes a simple three parameters transitional plasticity model to predict the compression response of clayey soil more accurately. The proposed model considers that the irrecoverable deformation due to relative sliding between the adjacent particle and particle groups has possibility from beginning of the loading in over-consolidated region as well. © ASCE.