Impact of Land Use Land Cover (LULC) Change on Surface Runoff in an Increasingly Urbanized Tropical Watershed

Water Resources Management - Upper-Brantas watershed in East Java, Indonesia, is a tropical watershed experiencing rapid landscape change, a phenomenon typical to developing countries. This study...     

Study on the electronic band structure of ZnO–SnO2 heterostructured nanocomposites with mechanistic investigation on the enhanced photoluminescence and photocatalytic properties

Journal of Materials Science: Materials in Electronics - Sol–gel method of synthesizing nanocomposites (NCs) of two metal oxides (ZnO & SnO2) was implemented along with the pristine...     

Energy Efficient Distributed Volterra Modeling Approach with ADMM-Based Sparse Signal Recovery

Wireless Personal Communications - Modeling the behavior of nonlinear systems in a distributed fashion is of paramount in many industrial applications. Distributed means no sensor node in the...     

Thermohydraulic performance of a new internal twisted ribs automobile exhaust heat exchanger for waste heat recovery applications

The performance of the thermoelectric-based waste heat recovery (WHR) system in an automobile greatly depends on the amount of heat extracted by the exhaust heat exchanger (EHE). In the present study, the thermohydraulic performance of the EHE having twisted ribs and the pressure drop across the entire heat exchanger have been experimentally investigated. The experiments were repeated for the various geometric parameters such as twist ratio (4-8), angle of attack (30°-90°), and pitch ratio (6-10) on the Reynolds number within the range of 2300 to 25,000. The heat transport and fluid flow characteristics were compared with an internally smooth EHE using the thermohydraulic performance parameter. The maximum heat transfer rate was improved at 164.22%. However, the specification of the twisted rib for superior performance has been obtained at twist ratio of 4 and pitch ratio of 8 with 60° angle of attack. The highest thermohydraulic performance parameter value revealed as 1.93 at the same configuration. With the change in twist ratio, the pitch ratio, angle of attack, and the heat transfer rate increased by 39.52%, 60.85%, and 40.70%, respectively. Thus, the efficient heat transfer with the twisted rib would improve the extent of WHR in automobiles.     

Computational and experimental studies on bed dynamics of a gas–solid fluidized bed using Geldart-A particle: A comparison

The bed dynamics of a two-dimensional gas–solid fluidized bed is studied experimentally and computationally using Geldart-A particles. Commercial software ANSYS FLUENT 13 is used for computational studies. Unsteady behavior of gas–solid fluidized bed is simulated by using the Eulerian–Eulerian model coupled with the kinetic theory of granular flow. The two-equation standard k?? model is used to describe the turbulent quantities. The simulation predictions are compared with experimentally observed data on volume fraction, bed pressure drop and bed expansion ratio. The results of simulations are found to be in close agreement with the experimental observations, implying that computational fluid dynamics (CFD) can be used for the design of an efficient bench-scale catalytic fluidized bed reactor.     

On Predictability of Groundwater Level in Shallow Wells Using Satellite Observations

Management of groundwater resources needs continuous and efficient monitoring networks. Sparsity of in situ measurements both spatially and temporally creates hindrance in framing groundwater management policies. Remotely sensed data can be a possible alternative. GRACE satellites can trace groundwater changes globally. Moreover, gridded rainfall (RF) and soil moisture (SM) data can shed some light on the hydrologic system. The present study attempts to use GRACE, RF and SM data at a local scale to predict groundwater level. Ground referencing of satellite data were done by using three machine learning techniques- Support Vector Regression (SVR), Random Forest Method (RFM) and Gradient Boosting Mechanism (GBM). The performance of the developed methodology was tested on a part of the Indo-Gangetic basin. The analyses were carried out for nine GRACE pixels to identify relationship between individual well measurements and satellite-derived data. These nine pixels are classified on the basis of presence or absence of hydrological features. Pixels with the presence of perennial streams showed reasonably good results. However, pixels with wells located mostly near the stream gave relatively poorer predictions. These results help in identifying wells which can reasonably represent the regional shallow groundwater dynamics.     

Microstructural and Mechanical Properties of FSW Joints Between AA6101-T6 and AA6351-T6 Dissimilar Al Alloys

Friction stir welding of AA6101-T6 and AA6351-T6 dissimilar Aluminium alloys has been carried out at constant welding speed using a tapered cylindrical threaded tool pin with varying rotational speed. Change in microstructure and hardness near heat affected zone, nugget zone, and Thermo mechanically affected zone have been examined. Tensile tests results showed that the minimum loss of yield strength and ultimate tensile strength with minimised microstructural distortion in the weld correspond to 1100 r.p.m of tool speed. Electron probe micro analysis with energy dispersive spectroscopy result shows that the breakdown of inter granular precipitate of Mg₂Si is found to be equiaxed and it minimizes the heat affected zone, thus attributing to the increase of strength compared to welded joints of 900 and 1300 r.p.m tool speed. The mass% of Si decreases with increase in tool speed and forms finer Mg₂Si precipitates that attributes to reduction in strength with fibrous fracture appearance.     

Investigation of Premature Failure of a Coal-Fired Boiler Superheater Tube

Journal of Failure Analysis and Prevention - A metallurgical investigation has been carried out to ascertain the cause of premature failure of boiler superheater tube. The tube material was...     

Structural,electrical and ferroelectric characteristics of Bi(Fe0.9La 0.1)O3

Nowadays, much attention is paid for the development of lead-free complex or mixed metal oxides, which can be utilized for multi-functional devices. This communication provides the information on synthesis (by mixed oxide route) and physical properties (structural, electrical and ferroelectric) of the polycrystalline sample of Bi(Fe_0.9La_0.1)O₃ Analysis of the phase formation and basic crystal data of the material using X-ray diffraction (XRD) technique shows an orthorhombic symmetry with well-defined cell parameters. It has been shown that a small amount (10%) of La substitution at the Fe site of BiFeO₃ suppresses the impurity phase usually observed during phase formation of BiFeO₃. The average crystallite size, calculated through applying Scherrer's technique, was found to be 68?nm. For the study of surface morphology (grain size and distribution) of the compound, the scanning electron microscope (SEM) was used. The grains of different dimension were found homogeneously distributed at the entire surface of the sample. The La substitution strongly affects the capacitive (dielectric) and resistive (electrical) characteristics of bismuth ferrite in a wide range of frequency and temperature. The contributions of grains and grain boundaries in the capacitive as well as in the resistive properties of the material at different temperatures and frequencies were studied by means of the impedance spectroscopy technique. This study has provided numerous useful and interesting data which may find potential industrial applications.