Pitambar Gautam

Mapping of subsurface karst structure with gamma ray and electrical resistivity profiles: a case study from Pokhara valley, central Nepal

Electrical resistivity (sounding with Schlumberger array and dipole-dipole imaging) and natural gamma ray intensity measurements were made over the karst features (subsurface flow-channels, solution cavities, sinkholes) in the Pokhara valley, central Nepal. In the Powerhouse area, the upper 60-80 m section of the basin-filling Quaternary sediments is represented by layered clastic sediments (gravel, silt, clay) that are represented by KQ-type (1 3>4 ) electrical sounding curves. The true electrical resistivity of the layers has a wide range of variation (a few hundreds to several tens of thousands of ohm.m) such that it is possible to determine both the vertical and lateral subsurface geological variations by integrating the electrical resistivity profiling and sounding techniques. Total gamma ray intensity profiles measured over various karstified locations reveal significant anomalies (up to 100 counts per second, cps) over the known or unknown subsurface openings. In the Powerhouse area, presence of a network of at least three linear NNE-SSW oriented subsurface channels, made by past and present underground flowchannels, is inferred. In interpreted electrical image profiles, contours of elevated resistivity reflect the cross-sectional geometry of cavities. The gamma-ray method is sensitive to nearsurface cavities while the electrical image effectively locates the void spaces at intermediate (up to 5-20 m) depths. An exploration program involving rapid radiometric mapping followed by selective electrical imaging is recommended for future exploration of karst-prone areas in the valley.

Where did rotational shortening occur in the Himalayas? – Inferences from palaeomagnetic remagnetisations

In metacarbonates of the Lesser (LH) and Tethyan (TH) Himalayas of Kumaon/Garhwal (N-India) characteristic remanent magnetisations carried by pyrrhotite (unblocking temperatures: 250^330‡C) and magnetite (demagnetising spectra: 15^50 mT) have been identified. Negative fold tests indicate remanence acquisition after the main folding phase, which is of short-wavelength character and occurs during the early orogenese of the Himalayas. A thermal or thermochemical origin of magnetisation is likely and the age of remanence acquisition is indicated to be about 40 Ma by 40 K/ 39 Ar cooling and 40 Ar/ 39 Ar crystallisation ages. In the Kumaon LH a long-wavelength tilting is indicated by a distribution of the remanence directions along a small-circle in N^S direction. Steepening of the remanence directions in the TH related to ramping on the Main Central Thrust (MCT) was not observed, in contrast to other related studies. In the Alaknanda valley of LH a 38 > 8 Ma age of remanence acquisition is supported by comparison of observed inclinations to the apparent polar wander path of India. Clockwise rotation of 20.3 > 11.7‡ (LH/Alaknanda valley) and 11.3 > 8.5‡ (TH) with respect to the Indian plate is observed, indicating that there is no significant evidence for rotational shortening along the MCT since about 40 Ma. Our results suggest that most of rotational underthrusting and oroclinal bending has not been accommodated by the MCT, but by the main thrusts south of it. The latest Miocene/Pliocene age of the Main Boundary Thrust indicates that oroclinal bending is a late-orogenic process.

Magnetic minerals and magnetic properties of the Siwalik Group sediments of the Karnali river section in Nepal

Sandstones and siltstones collected from the Siwalik molasse sequence (~ 16 to 5 Ma) of the Karnali river section have been studied for their magnetic properties. Behavior of the specimens during demagnetization (of the NRM and IRM) and magnetic susceptibility vs. temperature data suggest that goethite, maghemite/magnetite, and hematite are the main magnetic minerals in the section. Goethite, carrying a recent component, is the dominant magnetic mineral in the fine-grained lithologies from the lower part. Maghemite and magnetite, which also carry a secondary remanence, occur in the sandstones from the upper part. Hematite, mainly of detrital origin, is present in the whole sequence. The magnetic fabric is defined by mainly oblate AMS ellipsoids and a low degree of anisotropy (P′ < 1.20). The magnetic lineations (declinations: 75°–130° or 245°–310°; peak orientation: 290°/2.8°) are subparallel to the fold axes/bedding strikes/thrust fronts (WNW-ESE). The initial sedimentary-compactional fabric has been overprinted by a secondary tectonic fabric, which was probably induced by mild deformation active in the compressive tectonic setting.

Reflection of cross-disciplinary research at Creative Research Institution (Hokkaido University) in the Web of Science database: appraisal and visualization using bibliometry

This study describes the results of a preliminary bibliometric analysis of 611 research items, published between 1996 and 2011 by researchers affiliated with Creative Research Institution (CRIS) and the Center for Advanced Science and Technology (CAST), Hokkaido University (HU), retrieved from the Web of Science (WoS) database. CRIS has a primary mission to promote cutting-edge, world-class, trans-departmental research within HU, and it conducts fundamental, commercialization-related, cross-disciplinary research and nurtures young in-house/recruited researchers through targeted, innovative tenure-track programs in multiple disciplines. Its research output derives from 3- to 7-year-long time-bound projects funded strategically by HU, external grants [e.g., MEXT Super-COE HU Research and Business Park Project (FY2003-7)], industry-university collaboration with regional businesses, and endowments (e.g., Meiji Dairies). Analyses using co-words, bibliographic coupling, overlay map aided with visualization, etc., lead to the following inferences: (i) The published items comprise a dozen well-defined (inter-)disciplinary clusters, dominated by 3 macro-disciplines (biomedical science, 33%; chemistry, 21%; agricultural science, ca. 10%) that constitute 18 clusters used for mapping; (ii) research conducted by externally funded or endowed projects in the biomedical, physical and environmental science and technology fields (3 broad areas of aggregation derived from the Science Overlay Map) is interdisciplinary; and (iii) there is an apparently low visibility of publications from projects jointly executed with industries to an almost complete absence of output from CRIS in the fields of social sciences in the WoS database.

Comparative Analysis of Scientific Publications of Research Entities Using Multiple Disciplinary Classifications

This study attempts a comparative disciplinary analysis of a Web of Science (WoS) recorded dataset (ca. 15,000 core journal articles and reviews) of real publications for 5-years period by the research departments, dedicated to science, technology, engineering, mathematics, and medicine (STEMM), of a comprehensive university using different disciplinary schemes: Essential Science Indicators (ESI) 22 research fields, SCOPUS 27 subject areas and OECD Frascati 38 subordinate research fields. It demonstrates that assigning the publications to departments and disciplines followed by correspondence analysis and clustering of the contingency table comprising disciplinary share of publications results in enhanced understanding and visualization of the research output at different levels of disciplinary or research entities. Such exercise improves creation of publication subsets (for different research entities and disciplinary schemes) for further processing, visualization and interpretation with sophisticated bibliometric/scientometric tools including the science mapping techniques.

Deciphering the Department-Discipline Relationships within a University through Bibliometric Analysis of Publications Aided with Multi-variate Techniques

This study explores a practical approach to decipher the department-discipline relationships between the organizational research units dedicated to natural science, technology, engineering & medical (STEM) fields and 22 disciplinary categories used in Essential Science Indicators database (ESI 22 fields), for a Japanese national university as seen in a set of peer-reviewed journal publications (articles & reviews) indexed in the Web of Science (WoS) Core Collection database for a 5-years period. The procedure involved several steps such as (i) identification of publications of each organizational research unit through disambiguation of the affiliation data, (ii) assigning each publication to the corresponding ESI field based on journal title, (iii) aggregating bibliometric information of all publications for each research unit and discipline, and (iv) performing multivariate analysis, e.g., Clustering and correspondence analysis, to extract proximity relationships and internal structures that enable regrouping the obtained data and visualizing them using two-dimensional plots and bar diagrams. This approach may be easily adapted for analysis using other available disciplinary (subject areas or categories) schemes. Moreover, such analysis can be further extended to lower hierarchical levels, such as research divisions or research teams comprising a complex multidisciplinary department. The proposed affiliation-based analysis is useful for initial understanding the disciplinary contribution of the university departments to overall research output, e.g., For analysis of ranking based on performance for past 5-6 years tracing past history. It can be easily adapted to the bottom-up research performance analysis (based on current researchers) required for research administration or research strategy formulation based on the research output of the immediate past.

Detection of Bibliographic Coupling Communities Using Research Output (2004-2013) from Nepal

This study explores a country-level bibliometric analysis to extract bibliographic coupling (BC) communities as clusters of documents coupled through publications in their reference lists using the BiblioTool software. The 2004-2013 research output from Nepal represented by relatively small dataset of 3,011 documents (peer reviewed articles and reviews) indexed as core collections in the Web of Science (WoS) database was used. Setting a threshold of 10 documents, twenty-five BC communities, each with 12-443 documents, which provide a comprehensive picture on the research themes characterized by diverse items (keywords, subjects, journals, institutions, countries, authors, references, and title words) were discriminated. Twelve communities (i.e., 48%) deal with medical &amp; health sciences (maternal &amp; child health; tropical infectious diseases; cancer &amp; cardiovascular diseases; mountain sickness; blindness) closely linked also with social aspects; 4 communities with earth, environment and biodiversity (tectonics and natural hazards; environmental pollution, remediation and conservation; wild-life preservation); 3 communities with agriculture and veterinary sciences (pathogens of major crops (maize, wheat, rice) &amp; crop yields, plant genes, and dairy farming); 3 communities with nanomaterials and metal-alloys; 2 communities with pharmacology including ethnomedicine, and one community of 12 documents is related to galactic observations. These new results provide wider insights on the research volume &amp; diversity, international collaboration and the contributors (academic, national &amp; international, governmental &amp; non-profit agencies, etc.) engaged in research in Nepal.