Department of Environmental and Water Resources Engineering

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

School of Civil Engineering

Carbon based material represents an effective substitute for Pt counter electrodes (CEs) in Dye Sensitized Solar Cells (DSSCs). This study introduces a novel carbon coated ZnAl layered double hydroxides (C/ZnAl-LDH) can be utilised as an effective CE in DSSCs. C/ZnAl-LDH was synthesised by the pyrolysis of ZnAl-LDH using glucose solution. The synthesised C/ZnAl-LDH was characterised using TEM, SEM, XRD and BET analysis. The surface roughness of both Pt and C/ZnAl-LDH films were analysed using AFM spectroscopy. C/ZnAl-LDH slurry was pasted uniformly using doctor blade technique onto FTO glass substrate. The electrochemical measurements such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization recommends that C/ZnAl-LDH can be used as a CE due to its good reduction rate of I3- comparable with Pt CEs. The photovoltaic parameters were observed to be 0.66 V and 11.97 mA/cm2 for open circuit voltage (Voc) and short circuit current density (Jsc) respectively for C/ZnAl-LDH CE. The assembled cell with C/ZnAl LDH CE having power conversion efficiency (PCE) of 3.18% is comparable to Pt CE having 4.62% which is measured under the similar testing conditions. © 2020 International Solar Energy Society

World University root node

Vellore Campus

Solar Energy

Fabrication and performance analysis of a low cost, Pt free counter electrode using carbon coated ZnAl layered double hydroxide (C/ZnAl-LDH) for dye sensitized solar cells

Concrete is a widely known construction material that has been engineered to obtain certain desirable mechanical and durability properties. This research aims at studying the applicability of Perlite Powder (PP) as a partial replacement material of cement. Furthermore, this material possesses resistance to elevated temperatures. In the present study, the researchers has worked on two diferent types of concrete viz., Ternary Blended Concrete (TBC) by partially replacing cement with PP and Silica Fume (SF) and a Binary Concrete (BC) made by replacing PP partially alone with cement. In addition to Normal Concrete (NC), different mixes were prepared by replacimg cement with 1%, 3%, 5% and 7% of PP, whereas SF with 10% is maintained constant in all TBC mixes and PP is varied from 1% to 7% with an increment of 2%. In addition to room temperature, the specimens were exposed to different elevated temperatures, such as 200°C, 400°C, 600°C and 800°C, respectively. Experimental studies, like compression test, XRD, SEM, EDAX and TGA-DTA analyses, were conducted. The results of these experiments concluded BC with 5% replacement of PP to possess maximum strength as well as better thermal properties. © 2020 JUST. All Rights Reserved.

Department of Structural and Geotechical Engineering

Jordan Journal of Civil Engineering

Performance of ternary blended concrete and binary concrete made with Perlite powder at elevated temperatures

Many researchers have proposed different schemes of fiber reinforced polymer (FRP) wrapping to strengthen the Reinforced Concrete (RC) slab. However, the ideal system for FRP laminations is not readily available. A modular approach for strengthening of RC slabs (especially two-way slab) needs to be developed with respect to orientations and coverage area of FRP sheets in order to figure out the effective strengthening system. This paper describes the experimental study carried out to explore the effects of fiber reinforced polymers in different orientation and coverage areas to strengthen the structural members. Three systems of laminates have been used to strengthen the RC slabs using two types of fibers, namely carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite. The systems are classified with respect to the orientation of FRP sheets such as edge, corner and center wrapping. Each system has three proportions of FRP coverage area in the order of 25%, 35%, and 45%. A set of fifty-four slabs were fabricated and tested at the rate of three specimens for each variant. The performance of the flexural strength of two-way RC slabs with different strengthening systems has been evaluated and compared. It shows that all the systems of strengthening are effectively enhancing the flexural strength of two-way RC slabs. The extent depends on the system orientation and coverage area of the FRP sheet. The higher-order performance is noticed when the FRP lamination has higher contact with the slab area and with closer proximity to the loaded area. © 2020 by authors, all rights reserved.

Fulltext

Civil Engineering and Architecture

Evaluation of the effects of orientation and coverage areas of FRP lamination bonded with two-way RC slabs – a modular approach

Printed circuit boards (PCB) contain metallic and non-metallic fractions (NMF) that are hazardous and toxic when disposed of in a landfill. This paper emphasizes the feasibility of using NMF reclaimed from waste PCB's as a replacement to fly ash (FA) and metakaolin (MK) in a geopolymer mortar. Geopolymer mortar mixes were prepared with five FA-MK replacement ratios of 100-0, 90-10, 80-20, 70-30 and 60-40 and for each mix FA was also replaced with NMF by 5%, 10%, 15%, and 20%. The compressive strength and microstructures of geopolymer mortar were investigated and it was found that the addition of NMF enhanced the compressive strength. Maximum strength gain was found with 30% of MK and 15% of NMF in FA. The pozzolanic action of alumino-silicates was studied through SEM and XRD which reflected the formation of C-S-H gel with a dense geopolymer matrix along with the formation of CaCO3 crystals resulting in strength gain. The experimental studies provide a practical and sustainable recycling approach for the use of NMF in geopolymers for the construction industry. © 2020 Elsevier B.V.

Resources, Conservation and Recycling

A novel approach for the development of sustainable hybridized geopolymer mortar from waste printed circuit boards

This research aims to study the influence of organic additive and aggregate grain size in lime mortar hardening for producing compatible, high-performance and eco-friendly materials for conservation and restoration of heritage structures. Mortar mix with lime to sand ratio of 1:3 by mass and water to binder ratio of 0.75 was considered. Ficus Carica (Moraceae), commonly known as Fig fruit, was used as an organic additive in the mortar mix at 2, 4 and 6% in volume. River sand grounded for 5, 10 and 15 minutes, turning in changes in grain-size distrubution, was used in the mortar mix. Investigations on mortars were performed after 90 curing days; physical and mechanical properties were evaluated, along with mineralogical changes due to organic addition; the influence of organic and aggregate grading in carbonation rate was also assessed. Results indicate that the aggregate with retention value 45 ± 3% in grades between 2 mm to 425 micron and 425 micron to 75 micron; and the addition of organic additive at 4% in volume represents the optimum mix able to assure significant enhansement in carbonation rate and mechanical resistance. Polysaccharides in organic played the central role in the mineralogical transformation responsible for the measured enhanced performances. © 2020 Taylor &amp; Francis.

International Journal of Architectural Heritage

Evaluating the Impact of Organic Addition and Aggregate Gradation on Air Lime Mortar: New Compatible Green Material for Heritage Application

The utilization of industrial byproducts in landfill liners has shown increasing interest and continuous awareness in meeting their regulatory standards (i.e. 1&nbsp;×&nbsp;10−7&nbsp;cm/s, as per the United States Environmental Protection Agency) and often proved to be suitable as a liner material. This paper reviews the use and application of two largely produced industrial byproducts namely, thermal power stations (i.e. fly ash and bottom ash) and iron-steel industries (i.e. steel slag and blast furnace slag) as a liner in a landfill. A detailed and critical review of these byproducts with their experimental data on geotechnical properties such as index properties, compaction characteristics, compressive strength and hydraulic conductivity were presented. The aim of this paper is to provide geotechnical correlations on hydraulic conductivity with index properties, compaction characteristics and compressive strength of various industrial byproducts with soil types and additives were discussed. The presented correlations between hydraulic conductivity and other engineering properties will be helpful in determining the design parameters for landfill liner. From the set of resulted correlations, optimum percentage binders for each industrial byproduct are highlighted. Overall, these geotechnical correlations prove to be innovative which were obtained from experimental data will serve as a benchmark to validate the experimental results for various upcoming research works.

Journal of Cleaner Production

Correlation studies on geotechnical properties of various industrial byproducts generated from thermal power plants, iron and steel industries as liners in a landfill- a detailed review

The estimated average surface temperature using Q-Q CFM over the Cauvery river basin explains the rapid changes in climatic conditions. The study illustrates a significant increase in average surface temperature at Cauvery river basin due to global warming. The average temperature trend shows drop in the near future up to 0.5°C especially during the winter season. However, the trend rapidly increases in later years over the entire basin during summer seasons. The maximum change is observed in summer during the far future and which records the average temperature reading crossing 30°C at the lower Cauvery river basin. The maximum temperature change of 1.8°C to 2.7°C is estimated in far future time slice during summer season. The Q-Q CFM technique performs well and overcomes the drawbacks of the single change factor and other multiple change factor methods. The average temperature reading crossing a record 30°C at the lower Cauvery river basin nearing the end of the current century. The Q-Q CFM is computationally efficient and an effective technique for regional climate change assessments. The quantile to quantile change factor method is suggested to overcome the drawbacks of traditional change factor methods. © 2020 Ecological Society of India. All rights reserved.

Indian Journal of Ecology

Evaluation of surface temperatureand prediction of changes in future projections using quantile to quantile change factor methodologyover cauvery river basin-peninsular India

Flood Forecasting at Narmada River basin, Madhya Pradesh, India is carried out using an ensemble technique. The presented model has been compared with the individual models such as Support Vector Machine (SVM-EPS & SVM-NU), Random Forest, Multiple Linear Regression, Gradient Boosting, Extreme Gradient Boosting, and various performance measures has been used in order to evaluate and compare the performances of individual models with the stacked model. The evaluation results shows that the stacked model surpass all the individual models and shows improvement in the prediction of peak flows when compared to the individual models with minimal error. © 2020 Ecological Society of India. All rights reserved.

Short-term flood forecasting using ensemble learning

Hydro-climatic (HC) models have complex environments due to the integration of hydrological processes and climate indices for the assessment of historical and future scenarios. The approximation of HC models leads to a major uncertainty in the selection of optimal methods for processing, enhancement, and assessment. The present work developed a User-Friendly Interface (UI) in the R programming platform to enhance the geospatial HC models using machine learning concepts. Here, UI complies with various technologies together to perform consistently with input control, processing, and visualization. To validate this interface, a snow-dominated alpine watershed was selected. The results showed that, (a) UI assisted to downscale of the future climatic data into finer resolution, (b) boosted the efficiency of the geospatial model by adaptive random forest regression with NSE = 0.92 and 0.84, respectively. Moreover, UI designed to apply for different geospatial optimization problems which assist academicians, scientists, decision-makers, planners, and stakeholders, etc. © 2020 Informa UK Limited, trading as Taylor & Francis Group.

Geocarto International

Flexible user interface for machine learning techniques to enhance the complex geospatial hydro-climatic models with future perspective

Gainful utilization of mineral admixtures like Metakaolin (MK), Fly Ash (FA) and filler material like Waste Marble Powder (WMP) in various construction practices has become a new topic of interest in research area. This paper presents the studies regarding the use of MK and FA as cement substitution (partial) and WMP as fine aggregate replacement (partial) in Self-Compacting +Concrete (SCC). The pozzolanic nature of the MK and FA due to their high silica and alumina content enables them to be the most valuable Supplementary Cementing Materials (SCM’s) for utilization in the production of SCC. The MK was used as partial replacement of cement in seven different proportions of 5, 7.5, 10, 12.5, 15, 17.5 and 20% while as the FA replacement level (by weight of cement) was kept fixed at 15%. The fine aggregate was partially replaced by 20% WMP. To evaluate the influence of FA, the control mix with 15% FA substitution of cement was also designed. Thus, a total of nine mixes including the reference mix without fly ash were designed. The different tests to evaluate the workability were performed, which are presented in this paper. The specimens were tested in the hardened state at different ages for assessing the mechanical properties of SCC. The use of ternary binding blends consists of OPC+FA+MK and addition of WMP as fine aggregate replacement have shown a positive impact on fresh and mechanical characteristics of SCC. A significant correlation has also been observed between fresh properties and hardened properties of SCC. © 2020, Fundatia Serban Solacolu. All rights reserved.