Vertical component MAGSAT anomalies and Indian tectonic boundaries

MAGSAT vertical component (Z-component) of crustal anomalies are correlated for the first time with major geological and tectonic boundaries/features of the Indian subcontinent. A prominent ‘low’ is consistently observed on all the profiles centred between 19° and 23° latitudes over the broad Peninsular ‘high’. The other conspicuous ‘low’ indicated from the present work is confined to the region above Sarda depression (29° N to 31° N) in the foothills of Himalayas. Interesting magnetic signatures are identified over the Narmada-Son rift and Godavari graben.     

Modified seismic design of concentrically braced frames considering flexural demand on columns

Special concentrically braced frames (SCBFs) are considered as one of the most economical and effective lateral force‐resisting systems in structures located in the regions of high seismicity. Steel braces in a braced frame undergo large axial deformations in tension and compression to dissipate the seismic energy. However, past studies have shown that SCBFs exhibit the soft‐story hinge mechanisms and unpredictable failure patterns under earthquake loading conditions. These inelastic responses along with the use of continuous structural sections as columns over consecutive floors induce flexural demand that is not considered in the current design practice. In this study, the evaluation of seismic performance of nine SCBFs designed as per the current practice has been carried out for three different story heights (i.e., three‐story, six‐story, and nine‐story) and three types of brace configurations (namely, chevron, split X, and single X). Three additional design techniques are also explored based on (i) the inclusion of column moments in the design; (ii) the theory of formation of plastic hinges; and (iii) the design of braces considering the forces computed at their post‐buckled stages. Nonlinear dynamic analyses of these study frames have been evaluated numerically using a computer software Perform‐3D for a suite of 40 ground motions representing the design basis earthquake and maximum considered earthquake hazard levels. Analyses results showed that the SCBFs designed as per the modified procedures achieved the desired performance objectives without the formation of soft‐story mechanism. Copyright © 2017 John Wiley & Sons, Ltd.     

X-ray observation of XTE J2012+381 during the 1998 outburst

The outburst of X-ray transient source XTE J2012+381 was detected by the RXTE All-Sky Monitor on 1998 May 24th. Following the outburst, X-ray observations of the source were made in the 2–18 keV energy band with the Pointed Proportional Counters of the Indian X-ray Astronomy Experiment (IXAE) on-board the Indian satellite IRS-P3 during 1998 June 2nd–10th. The X-ray flux of the source in the main outburst decreased exponentially during the period of observation. No large amplitude short-term variability in the intensity is detected from the source. The power density spectrum obtained from the timing analysis of the data shows no indication of any quasi-periodic oscillations in 0.002–0.5 Hz band. The hardness ratio i.e. the ratio of counts in 6–18 keV to 2–6 keV band, indicates that the X-ray spectrum is soft with spectral index >2. From the similarities of the X-ray properties with those of other black hole transients, we conclude that the X-ray transient XTE J2012+381 is likely to be a black hole.     

Seismic retrofit of MRF buildings using decentralized semi‐active control for multi‐target performances

Numerous structures have been designed and built without taking earthquake ground motions or outdated seismic design codes into account. In order to improve the seismic performance of existing structures, many retrofit approaches based on performance‐based design have been developed. However, some of these approaches are inapplicable due to structural limitations or because they were developed with the assumption of single‐degree‐of‐freedom, which does not take higher modes into account. To overcome the limitations of these traditional methods, a multi‐performance‐based control design (MPBCD) methodology has been proposed by integrating a decentralized semi‐active control algorithm, magnetorheological dampers, and an advanced multi‐objective optimization method to provide various sets of retrofit control designs to satisfy multiple target performances under multiple seismic intensities without changing structural cross‐section sizes or material properties. This MPBCD method provides engineers with numerous sets of control designs (i.e., control device layouts with control design parameters) to help them select proper control designs to retrofit existing building structures and improve seismic performance. Copyright © 2016 John Wiley & Sons, Ltd.     

A Platform for Visualizing and Experimenting with Measures of Semantic Similarity in Ontologies and Concept Maps

This article describes research in the ongoing search for better semantic similarity tools: such methods are important when attempting to reconcile or integrate knowledge, or knowledge‐related resources such as ontologies and database schemas. We describe an extensible, open platform for experimenting with different measures of similarity for ontologies and concept maps. The platform is based around three different types of similarity, that we ground in cognitive principles and provide a taxonomy and structure by which new similarity methods can be integrated and used. The platform supports a variety of specific similarity methods, to which researchers can add others of their own. It also provides flexible ways to combine the results from multiple methods, and some graphic tools for visualizing and communicating multi‐part similarity scores. Details of the system, which forms part of the ConceptVista open codebase, are described, along with associated details of the interfaces by which users can add new methods, choose which methods are used and select how multiple similarity scores are aggregated. We offer this as a community resource, since many similarity methods have been proposed but there is still much confusion about which one(s) might work well for different geographical problems; hence a test environment that all can access and extend would seem to be of practical use. We also provide some examples of the platform in use.     

Utilization of remotely sensed data for soil resource mapping and its interpretation for landuse planning of Bhiwani district,Haryana

Visual interpretation of IRS-1A LISS-II (October 1988 & Feb. 1989) FCC (spectral bands 2, 3 & 4) at 1:50,000 scale was carried out for soil resource mapping of Bhiwani district (Haryana State) covering on area of 5099 sq. kim. Based on image characteristics, element analysis (landform, vegetation & erosion) and field traverses, physiography-soil relationship was established. Major physiographic units identified in the area are: Aeolian plain, Fluvio-acolian plain, Transitional plain, Alluvial plain, Hills and Pediments. Area was divided into 34 subunits. Final physiography-soil map on 1:50,000 scale was prepared. Taxonomically, the soils of each unit were classified and are found as: In aeolian plain—Typic Torripsamments/coarse loamy, Typic Camborthios; Fluvio-aeolian plain-Aridic Ustipsamments/coarse loamy/fine loamy Typic/Udic Ustochrepts; Alluvial plain—Typic Ustipsamments/coarse loamy/fine loamy Typic/Udic Ustochrepts; Hills and Pediments—fregmental Lithic Torriorthents/Typic Torripsamments. Interpretation for each subunit was made regarding land suitability for various land utilisation types. It was found that hills and pediments, dunal ridges, dunal complexes and serub-lands are best suitable for forestry and horiculture plantations. Dunal plains and inter-dunal depressions are best suitable for gram/bajra/oilseeds/guar, very gently sloping dunal plain and low lying plain are suitable for wheat/arhar/cotton/sunflower.     

Environmentally sustainable use of sandstone slurry in self-compacting concrete

Natural Hazards - Dried sandstone slurry (DSS) is generated during mining and processing of stone and is accounted as man-made hazardous waste material, contaminating the environment in nearby...     

Heat transfer in unsteady MHD couette flow of an electrically conducting,viscous, incompressible rarefied gas

An analytical study is performed to examine the heat transfer characteristics on the flow of a viscous, incompressible rarefied gas in a parallel plate channel under the action of transverse magnetic field when (i) suction velocity normal to the plate is constant, (ii) the second plate oscillates in time about a constant non-zero mean, (iii) fluid is subjected to a constant heat source of absorption type. Apprximate solutions for velocity, temperature, phase, and amplitude of skin-friction and rate of heat transfer are evaluated. Mean temperature profiles, phase and amplitude of rate of heat transfer at both plates are discussed graphically followed by a quantitative discussion. Mean rate of heat transfer is tabulated in Table I.     

An assessment of the geomorphodiversity and land use/cover change (LUCC) effects associated with landslides in Meghalaya,India

The Shillong Plateau in the Eastern Himalayas is exposed to high seismicity, neo-tectonic activity and orographic precipitation that aggravated landslides in the region by affecting hillslope processes. Landscape development is influenced by landslide phenomenon and depends upon geomorphic processes and geomorphodiversity (GmD). It is linked intimately with geomorphology, hydrology and soil type. This study uses a remote sensing and GIS-based approach to assess the spatial linkage between GmD and landslide distribution in Meghalaya (India). GmD index (GmDI) is developed using geological, morphometric and geomorphological parameters and analysed with landslide distribution. The landslide distribution considering land use/cover change (LUCC) is also examined. The result shows that the region with high-relief, valley and depression zone, mainly along the Dauki fault, have a high to a very high GmDI. About 61% of landslide localities are in zones of high GmDI, concentrated in the central and eastern parts of Meghalaya. Density analysis of the very high class (class 5) of GmD confirms the same. Most of these landslides occur in dense and light-vegetated landmasses. However, the LUCC analysis reveals a significant increase in the built area on steeper slopes (average expansion ratio of 2.30 for slopes >15°) between 2017 and 2022, indicating a rising threat of landslides in urban areas of Meghalaya. The study presents the importance of GmD in active tectonic regions with particular reference to landslide potential and recent LUCC. It can aid decision-makers in planning sustainable developments and risk mitigation strategies for landslide hazards and geoconservation.