Extended C-terminus and length of the linker connecting the G-domains are species-specific variations in the EngA family of GTPases

AbstractEngA is an essential protein involved in ribosome biogenesis. It is an unique GTPase, possessing two consecutive G-domains. Using sequence and phylogenetic analysis, we found two intriguing variants among EngA homologues – one with a shorter linker joining the G-domains and another with a longer linker, which additionally possesses an extended C-terminus. Interestingly, while the former variant is mainly restricted to firmicutes, the latter is found in nonfirmicutes. Chimeric proteins with interchanged linkers and extensions were generated to gauge the importance of these elements. Ribosome interaction experiments employing the chimeric proteins suggest that a precise combination of the linker and C-terminal extension are important features regulating EngA ribosome interactions in a variant-specific manner

The Potential of Channel Specific Reflectance in Landsat 8 OLI Sensor for Retrieving Coal Fire Affected Pixels

Coal fire is a serious threat in major coal producing countries across the globe and poses significant constraints in mining operations, often leading to environmental degradation. The applications of thermal and shortwave infrared remote sensing play a substantial role in systematically detecting and monitoring the coal fire. Over the last few decades, researchers have extensively examined the importance of spectral radiance for retrieving reliable pixel-integrated temperature threshold to delineate coal fire from its background. However, such an assumption does not necessarily consider the local information, thereby leading to difficulty in isolating the actual coal fire affected pixels. Therefore, we propose to utilise the channel specific reflectance to retrieve the thermally anomalous pixels in coal fire related applications using Landsat 8 OLI data. This paper explores the practicability of incorporating the active fire detection technique using channel specific reflectances based on both fixed and contextual thresholds in the Jharia coalfield, India

3D Printed Porous Dielectric Substrates for RF Applications

In this study, dielectric properties of Acrylonitrile butadiene styrene (ABS) thermoplastic material with different fill-densities are investigated. Three separate sets of samples with dimensions of 25 mm × 25 mm × 5 mm were created at three different machine preset porosities using a LulzBot 3D printer. To understand the actual porosities of the samples, a 3D X-ray computed tomography microscope was used. The great advantage of this 3D microscopy is that it is fully non-destructive and requires no specimen preparation. Hence, the manufacturing defects and lattice variations can be quantified from image data. It is observed that the experimental pore densities are different from the factory preset values. This provides insight to further understand pore distribution-property relationships in these dielectric materials. Micro-strip patch antennas were then created on the 3D printed ABS substrates. The samples were then tested using a vector network analyzer (VNA) and resonant frequencies were measured. It is observed that the resonant frequency increases with an increase in porosity. These results clearly demonstrate the ability to control the dielectric constant of the 3D printed material based on prescribed fill density. Copyright © 2016 by ASM

3D Printed Porous Dielectric Substrates for RF Applications

In this study, dielectric properties of Acrylonitrile butadiene styrene (ABS) thermoplastic material with different fill-densities are investigated. Three separate sets of samples with dimensions of 25 mm × 25 mm × 5 mm were created at three different machine preset porosities using a LulzBot 3D printer. To understand the actual porosities of the samples, a 3D X-ray computed tomography microscope was used. The great advantage of this 3D microscopy is that it is fully non-destructive and requires no specimen preparation. Hence, the manufacturing defects and lattice variations can be quantified from image data. It is observed that the experimental pore densities are different from the factory preset values. This provides insight to further understand pore distribution-property relationships in these dielectric materials. Micro-strip patch antennas were then created on the 3D printed ABS substrates. The samples were then tested using a vector network analyzer (VNA) and resonant frequencies were measured. It is observed that the resonant frequency increases with an increase in porosity. These results clearly demonstrate the ability to control the dielectric constant of the 3D printed material based on prescribed fill density. Copyright © 2016 by ASM

Effect of Processing Conditions and Material Properties on the Debond Fracture Toughness of Foam-Core Sandwich Composites: Experimental Optimization

The structural performance and reliability of the foam-core sandwich composites are known to be dependent on the strength of the core-skin bonding. Mechanical tests have repeatedly demonstrated that the failure modes for the sandwich during flexural, compression, and tension loading are first triggered by the failure of the interface or the sub-interface zones between the core and the skin. Once this failure mode sets in, core shear and delamination progress rapidly, leading to the final failure of the sandwich construction. The strength of the core-skin bonding depends on the chemical reactions taking place during the cure process. The effect of processing parameters and material properties on the core-skin bonding strength were investigated experimentally. The skincore debond fracture toughness was measured using Tilted Sandwich Debond specimens. Verifying the heuristics developed in the previous part of this paper [1], we achieved a 78% increase in debond fracture toughness with elevated temperature processing, and observed reduced variability with higher suction pressures. We also saw increase in debond fracture toughness with foam density, validating the assumption that interfacial bonding controls the debond fracture toughness. An increase in resin uptake with foam density was an interesting observation from these experiments.