Assessing environmental impacts of aviation on connected cities using environmental vulnerability studies and fluid dynamics: an Indian case study

As the annual air passenger traffic in India is increasing steeply (13.52 million in 2012 compared to 11.02 million in 2010), an environmental impact assessment on important cities connected by air is becoming increasingly indispensable. This study proposes an innovative screening method that uses a modified Environmental Vulnerability Index (EVI). This modified EVI calculator includes aviation-related parameters and can be used to assess the environmental vulnerabilities of political states and cities, in addition to countries as is being already done. This study also suggests the need to include aspects of human comfort in the screening process through the use of state-of-the-art computational fluid dynamical software and large eddy simulations which can be used to estimate forces experienced by aircraft of different sizes during in-flight turbulence for various weather conditions. A comparative analysis is presented on how changing the size of the aircraft operating in a particular route between the cities of Chennai and Bengaluru has better implications on both passenger comfort and the environment. It is observed that if commercial airlines incorporated fewer medium-sized aircraft, there would be a significant reduction in the environmental vulnerability of the two connected cities.     

An Ultra-low Carbon, Thermomechanically Controlled Processed Microalloyed Steel: Microstructure and Mechanical Properties

In the current study, a novel ultra-low carbon, high-molybdenum-bearing microalloyed steel has been thermomechanically processed. Transformation of this steel during continuous cooling has been assessed. Variation in the microstructure and mechanical properties at different finish rolling temperatures has been studied. The average grain size, misorientation of grain boundary, and distribution of ferrite grains have been analyzed by using electron backscatter diffraction. The lower yield strength (251 to 377?MPa) with moderate tensile strength (406 to 506?MPa) along with high ductility (30 to 47?pct) has been achieved in the selected range of finish rolling temperatures. Superior impact toughness value in the range of 153 to 162?J is obtained in the subsize specimen even at subzero temperatures (233?K [?40?°C]), which is attributed to fine average ferrite grain size. The acicular ferrite dominated microstructure obtained at the 1023?K (750?°C) finish rolling temperature is the most attractive microstructure for pipeline applications due to its excellent combination of strength and toughness.     

Fission of Multielectron Bubbles in Liquid Helium Under Electric Fields

Multielectron bubbles (MEBs) are cavities in liquid helium which contain a layer of electrons trapped within few nanometres from their inner surfaces. These bubbles are promising candidates to probe a system of interacting electrons in curved geometries, but have been subjected to limited experimental investigation. Here, we report on the observation of fission of MEBs under strong electric fields, which arises due to fast rearrangement of electrons inside the bubbles, leading to their deformation and eventually instability. We measured the electrons to be distributed unequally between the daughter bubbles which could be used to control the charge density inside MEBs.     

Effect of Reheating Temperature and Cooling Treatment on the Microstructure,Texture, and Impact Transition Behavior of Heat-Treated Naval Grade HSLA Steel

In order to achieve the desired mechanical properties [YS > 390 MPa, total elongation >16 pct and Charpy impact toughness of 78 J at 213 K (?60 °C)] for naval application, samples from a low-carbon microalloyed steel have been subjected to different austenitization (1223 K to 1523 K) (950 °C to 1250 °C) and cooling treatments (furnace, air, or water cooling). The as-rolled steel and the sample air cooled from 1223 K (950 °C) could only achieve the required tensile properties, while the sample furnace cooled from 1223 K (950 °C) showed the best Charpy impact properties. Water quenching from 1223 K (950 °C) certainly contributed to the strength but affected the impact toughness. Overall, predominantly ferrite matrix with fine effective grain size and intense gamma-fiber texture was found to be beneficial for impact toughness as well as impact transition behavior. Small size and fraction of precipitates (like TiN, Nb, and V carbonitrides) eliminated the possibility of particle-controlled crack propagation and grain size-controlled crack propagation led to cleavage fracture. A simplified analytical approach has been used to explain the difference in impact transition behavior of the investigated samples.     

Influence of ionic pretreatment on the performance of solid electrolyte dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) were manufactured with liquid iodine/iodide electrolyte solution in acetonitrile and a solid electrolyte based on plasticized poly(ethylene oxide) (PEO). Two types of titania electrodes manufactured from two-ingredient precursors were used to assess the efficacy of the solid electrolyte and the improvement produced by two chemical treatments. Solid electrolyte devices with a liquid electrolyte pretreatment applied to the electrolyte-oxide interface demonstrated improved photovoltaic performance compared to untreated solid electrolyte devices and solid electrolyte devices given an electrode-bulking sol treatment. Devices using electrodes made from hydrothermally synthesized titanate nanotubes resulted in lower performance than those made from the typically-used titania nanopowder, with significant performance loss resulting from the substitution of solid for liquid electrolyte, indicating the critical dependence of performance on electrolyte infiltration into the oxide layer.     

Text box proposals for handwritten word spotting from documents

International Journal on Document Analysis and Recognition (IJDAR) - In this article, we propose a new approach to segmentation-free word spotting that is based on the combination of three...     

Microtextural analysis of coke from single and binary blend and its impact on coke quality

Coke microtexture and microstructure is a function of feed coal composition and carbonisation process. If the process remains constant, the composition plays a vital role in developing the microtexture and microstructure which also reflects the coke quality. Knowledge of the influence of coal composition and characteristics on coke quality is a must for formulating a coal blend for coke making. To better understand how the coal transforms into coke requires the ability to correlate the microtextural and microstructural features to coal properties. Petrography is an important tool for comparing the feed coal and corresponding coke. In the present study, cokes manufactured from single coals and two-component blends under similar coking conditions were studied under the microscope to provide valuable information to coke makers. Not only the rank and quantification of macerals but also the association of macerals and minerals play an important role. Also the size and type of inertinite affect the coke quality. Micro-cracking, crack lengths and fissures identify the zone of weakness, whereas microtexture of cell walls suggests the strength-controlling parameters of coke. Pictorial concept followed in the present study is given below:     

Dendrite Morphological Analysis on SMA,GMA, and PGMA Welding of Dissimilar 304LN Austenitic Stainless Steel and Micro-alloyed Steel

Dissimilar metal welding between the austenitic stainless steel and micro-alloyed steel was widely used in high-temperature applications in power stations and petrochemical plants. In the current research, the dissimilar metals between austenitic stainless steel and micro-alloyed steel have been joined by shielded metal arc welding (SMA), gas metal arc welding (GMA), and pulse gas metal arc welding (PGMA) processes. Welded samples of the aforementioned processes were subjected to comparative studies pertaining to the dendrite morphological characteristics. The study reveals that the process parameters affect the growth of dendrite arm because of the variation in the coefficient of thermal conductivity, expansion, and metallurgical incompatibility of the metals. In the PGMA welding process, the dendrite length decreases, while its width increases in all the locations of the weld by varying dimensionless factors ϕ (0.05, 0.15, and 0.25) and keeping its heat input as constant (Ω—11.2 kJ/cm). Among the welded joints, the PGMA weld joint comparatively exhibit shorter length (20 µm) and width (4 µm) of dendrite arm than the welded joints of the GMA and SMA processes. The change in the dendrite dimension is observed to be due to the variation in the dimensionless factor ϕ and the quantity of heat transfer to the weld (QT). The studies have been systematically planned in order to gain advanced scientific knowledge to establish superior technique for multi-pass PGMA welding of thick section of austenitic stainless steel to micro-alloy steel with respect to that used with conventional welding process.