Civil Engineering

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Two commercial diatomaceous earths were used as supports for the preparation of Mn/Co binary metal catalysts at different metal loads (5 to 10 wt \% Mn and 5 to 15 wt \% Co) by incipient wetness deposition. The activity of the prepared catalysts towards the complete oxidation of benzene to CO2 and water was investigated between 100 and 400◦ C. Raw supports and synthesized catalysts were characterized by XRD, N2 physisorption, SEM-EDS, H2 -TPR, and TPD. The purification treatment of food-grade diatomite significantly affected the crystallinity of this support while reducing its specific surface area (SSA). A loss of SSA, associated with the increase in the metal load, was observed on samples prepared on natural diatomite, while the opposite trend occurred with food-grade diatomite-supported catalysts. Metal nanoparticles of around 50 nm diameter were observed on the catalysts’ surface by SEM analysis. EDS analysis confirmed the uniform deposition of the active phases on the support’s surface. A larger H2 consumption was found by TPR analysis of natural diatomite-based samples in comparison to those prepared at the same metal load on food-grade diatomite. During the catalytic oxidation experiment, over 90\% conversion of benzene were achieved at a reaction temperature of 225◦ C by all of the prepared samples. In addition, the formation of coke during the oxidation tests was demonstrated by TGA analysis and the soluble fraction of the produced coke was characterized by GC-MS. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

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Catalysts

A comparative study of Mn/Co binary metal catalysts supported on two commercial diatomaceous earths for oxidation of benzene

The tropical cyclones (TCs) are often associated with unprecedented heavy rainfall, and have a pronounced impact over East coast states of India. This study has done comprehensive investigation on contribution of two episodic TCs rainfall to the annual rainfall using satellite based rainfall estimates from TMPA-3B42 (daily product), and rainfall data from India Meteorological Department (IMD) observations. We analyzed both rainfall distribution and inundation extent induced by two episodic severe cyclonic events (Super–cyclone 1999 and Phailin 2013), and assessed their impacts on hydro-meteorological parameters and agricultural productivity. Our findings suggest that rainfall originated from two episodic TCs significantly contributed to the annual rainfall, accounting for about 5–25\% over the coastal districts of Odisha state. Howbeit, it was subjected to underestimation owing to rainfall biases of TMPA-3B42 during TCs, which was evident when it was compared with IMD measurements. Along the TCs track, intense rainfall followed by peak discharge from the river basins caused substantial flooding and inundation of croplands over the coastal regions. The TC related rainfall, strong winds, and storm surges have diminished kharif season's agricultural production, as crops were submerged during these periods. Overall, the rice production has been diminished by 57\%, and this rice production even lowered by more than 70\% in some of the districts. Most severely affected districts (Ganjam, Puri, Cuttack, Jajpur, Bhadrak, Baleshwar) were located close to landfall, where croplands are dominating land use type. These results inferred that the isolated severe TCs could bring significant amount of rainfall, which would cause widespread impacts on agricultural activities. Finally, the findings of this unique study recommends that the satellite based rainfall estimate data can act as a valuable input for flood modeling and crop monitoring at different scales to alleviate hydro–meteorological and agricultural impacts. © 2018 Elsevier B.V.

Remote Sensing Applications: Society and Environment

Investigating the effects of episodic Super-cyclone 1999 and Phailin 2013 on hydro-meteorological parameters and agriculture: An application of remote sensing

Bimodal composite structures conjugating both high hardness and fracture toughness can effectively counter erosion induced degradation. The present work successfully develops bimodal metal matrix composite claddings using facile and cost-effective microwave technique, exploiting the direct and effective coupling phenomenon of reinforcement with microwave irradiation. For comprehensiveness, unimodal micro-/nano-reinforced clads were also developed. Interestingly, unimodal micro-composite clad showed refined structure compared to nano counterpart which is due to the effective coupling of later with microwave irradiation causing particle dissociation into the matrix. Compared to unimodal claddings, bimodal showed the highest hardness and indentation fracture toughness. In addition to ex-situ reinforcements, intrinsically evolved secondary phases also effectively contributed towards improved mechanical properties. The better performance of the bimodal clad is related to reduced agglomeration and dissociation of the nanoparticles, refined microstructure and constructive interaction between micro and nano-reinforcements. The phenomenal mechanical properties of bimodal composite clad resulted in improved durability compared to unimodal composite claddings under different tribological test conditions. © 2018 Elsevier B.V.

Mechanical Engineering

Surface and Coatings Technology

Towards highly durable bimodal composite claddings using microwave processing

{\textcopyright} 2018 American Society of Civil Engineers. The quantification of evapotranspiration (ET) is highly important in water resources planning. The most reliable method for determining ET is to measure it in the field using lysimeters. However, the use of lysimeters for measurement of crop ET (ETc) is both expensive and time consuming, thus necessitating a cheaper yet reliable alternative method. One such method is to determine ET using the Penman-Monteith equation, which requires daily meteorological data as inputs. Three vapor pressure models (Models 1-3) are mentioned in Irrigation and Drainage Paper-56 of the Food and Agriculture Organization (FAO-56) for the estimation of actual vapor pressure (ea) that is used in the estimation of reference ET (ET0) by the FAO Penman-Monteith equation. Model 1, which uses daily maximum and minimum temperature and relative humidity (RH) data, is the preferred method to estimate ea; other models are used in data-constrained situations. Another vapor pressure model (Model 5) is proposed in this study. The performance of the vapor pressure models along with two other models (Models 4 and 6) existing in the literature is compared with that of Model 1 in estimating daily ea and ET0 values. The ea values were underestimated by Model 2, whereas Models 3, 4 and 5 overestimated ea. Results show that Models 4 and 5 (proposed model) performed better than FAO-56 Models 2 and 3 for estimating daily ea values for Roorkee station, India. However, Model 4, which uses only daily mean temperature and RH data, has lower accuracy in ET0 estimation when compared to Model 5. This is because Model 4 underestimated the daily saturation vapor pressure values. This suggests that daily mean temperature is not enough for the accurate estimation of daily ET0 values. The overall performance of Model 5, which uses the Lawrence dewpoint temperature-RH relationship, was more consistent and closest to Model 1 when compared to the other vapor pressure models for the study region in data-constrained situations. Furthermore, the effect of wind speed ranges on the performance of the vapor pressure models in ET0 estimation is also assessed. The effect of vapor pressure models in ET0 estimation is not considerable for light winds but becomes substantial for higher wind speeds.

Journal of Irrigation and Drainage Engineering

Evaluation of the Vapor Pressure Models in the Estimation of Actual Vapor Pressure and Evapotranspiration

AGU Fall Meeting Abstracts

Numerical Model for Soil Moisture Simulation in Cropped Area

Due to their exceptionally high specific strength and specific stiffness, single-and multiwalled carbon nanotubes (SWCNTs and MWCNTs) are widely used as reinforcement in metallic, ceramic and high-performance polymer matrices. The mechanical properties, including stiffness, strength and bending characteristics, of carbon nanotubes (CNTs) are greatly influenced by a number of factors, including CNT diameter, chirality, number of concentric walls in MWCNTs, chemical functionalization, surface defects and so forth. However, the challenges associated with the separation of a single CNT and its experimental characterization lead to less reliable and varying estimations of mechanical properties. This chapter presents a careful overview of the elastic and inelastic mechanical properties of isolated single-and multiwalled carbon nanotubes, determined using tedious experiments and elaborated computational methods and their dependence on nanotube physical/chemical properties.

Carbon Nanotube-Reinforced Polymers: From Nanoscale to Macroscale

Mechanical properties of isolated carbon nanotube

The authors regret that the sources from which the RfC (reference concentration) and the IUR (inhalation unit risk) values were obtained for estimation of RfD (reference dose, presented in Table 2) and SF (slope factor, presented in Table 3) were not clearly indicated in the published article due to an oversight. The revised tables with improved clarity are given below. [Table presented] The authors apologize for any inconvenience caused. © 2018 Elsevier Ltd

Atmospheric Environment

Corrigendum to “Chemical composition and acidity of size-fractionated inorganic aerosols of 2013–14 winter haze in Shanghai and associated health risk of toxic elements” [Atmos. Environ. (2015) 259–271](S1352231015303952)(10.1016/j.atmosenv.2015.09.053)

This article highlights recent advances in the development of transition metal-based catalysts for formaldehyde oxidation, particularly the enhancement of their catalytic activity for low-temperature oxidation. Various factors that enhance low-temperature activity are reviewed, such as morphology and tunnel structures, synthesis methods, specific surface area, amount and type of active surface oxygen species, oxidation state, and density of active sites are discussed. In addition, catalyst immobilization for practical air purification, reaction mechanism of formaldehyde oxidation, and the reaction parameters affecting the overall efficiency of the reaction are also reviewed. © 2017 Taylor & Francis.

Catalysis Reviews - Science and Engineering

Advances on transition metal oxides catalysts for formaldehyde oxidation: A review

Sediment particles entrainment from the channel bed is influenced by flow turbulence which creates fluctuating shear stress at the bed. Sweep quadrant event is considered to be most important for entrainment of sediment particles as it exerts forces in the flow direction resulting in rolling and sliding of sediment particle. Similarly, the ejection event has been considered important for sediment transport since these events maintain the sediment particles in suspension. In this paper, the nature of bursting events and in particular, the sweep events were studied in a model of braided river with a central island. The instantaneous velocities of flow were measured using the ADV. The turbulent stresses were determined from these instantaneous velocities. Box–Cox transformation is applied to transform the original data into a normally distributed data. The velocity measurements near the braided bar were made at 12 vertical sections using an ADV. The maximum value of turbulent kinetic energy and the Reynolds shear stress was found to occur near the bed level. These turbulent parameters have greater values for scouring points, this shows that these parameters are related with the scouring near the braided bar. © 2016 Indian Society for Hydraulics.

Center for Environmental Sciences & Engineering

ISH Journal of Hydraulic Engineering

Experimental study on bursting events around a bar in physical model of a braided channel

In present study, statistical optimization of biodiesel–derived crude glycerol fermentation to DHA by immobilized G. oxydans cells over polyurethane foam is reported. Effect of DHA (product) inhibition on crude glycerol fermentation was analyzed using conventional biokinetic models and new model that accounts for both substrate and product inhibition. Optimum values of fermentation parameters were: pH = 4.7, temperature = 31 °C, initial substrate concentration = 20 g/L. At optimum conditions, DHA yield was 89% (17.83 g/L). Effect of product inhibition on fermentation was trivial for DHA concentrations ≤30 g/L. At higher concentrations (≥50 g/L), kinetics and yield of fermentation showed marked reduction with sharp drop in Vmax and KS values. Inhibition effect was more pronounced for immobilized cells due to restricted transport of fermentation mixture across polyurethane foam. Retention of fermentation mixture in immobilized matrix resulted in higher localized DHA concentration that possibly enhanced inhibition effect. © 2017 Elsevier Ltd