U-Pb ages and Sr, Pb and Nd isotope data for gneisses near the Kolar Schist Belt: Evidence for the juxtaposition of discrete Archean terranes

Uranium-lead ages and Sr, Pb, and Nd isotopic data for gneisses near the Kolar Schist Belt and their interpretation as evidence for the juxtaposition of discrete Archean terranes were presented. The granodioritic Kambha gneiss east of the schist belt has a zircon age of 2532 + or - 3 Ma and mantle-like initial Sr, Pb, and Nd isotopic ratios. Therefore these gneisses are thought to represent new crust added to the craton in the latest Archean. By contrast, more mafic Dod gneisses and leucocratic Dosa gneisses west of the schist belt (2632 + or - 7 and 2610 + or - 10 Ma) show evidence for contamination of their magmatic precursors (LREE-enriched mantle-derived for the Dod gneisses) by older (greater than 3.2 Ga) continental crust. Fragments of this older crust may be present as granitic and tonalitic inclusions in the 2.6-Ga gneisses and in shear zones. The antiquity of these fragments is supported by their Nd, Sr, and Pb isotopic compositions and by 2.8 to greater than 3.2 Ga zircon cores

Tectonic setting of the Kolar Schist Belt, Karnataka, India

The tectonic setting of the Kolar Schist Belt and why the belt may represent a late Archean suture was discussed. The isotopic and chronological evidence that suggest diverse origins of the various packages of supracrustal rocks within the schist belt and the two gneiss terrains adjoining the belt were summarized. The eastern and western amphibolites were derived from sources at similar depths in the mantle (probably at similar ages, ca. 2.7 Ga), but these sources had distinct trace element compositions and histories. A distinctive feature of these differences was shown by the differences between the east and west amphibolites on a Ce vs. Nd diagram. In the gneisses the age and isotopic evidence suggest that the two terranes had distinct histories until after 2520 Ma and by 2420 Ma (Ar-40/Ar-39 age of muscovite in the sheared margin of the schist belt). Based on these data, the schist belt probably represents the site of accretion of diverse fragments (terrains) to the margin of the craton in the latest Archean, possibly as an Archean analog to the Phanerozoic North American Cordillera

The Hausdorff dimension of random walks and the correlation length critical exponent in Euclidean field theory

We study the random walk representation of the two-point function in statistical mechanics models near the critical point. Using standard scaling arguments we show that the critical exponent $\nu$ describing the vanishing of the physical mass at the critical point is equal to $\nu_\theta/ d_w$. $d_w$ is the Hausdorff dimension of the walk. $\nu_\theta$ is the exponent describing the vanishing of the energy per unit length of the walk at the critical point. For the case of O(N) models, we show that $\nu_\theta=\varphi$, where $\varphi$ is the crossover exponent known in the context of field theory. This implies that the Hausdorff dimension of the walk is $\varphi/\nu$ for O(N) models.Comment: 11 pages (plain TeX

Determining Glucose Isomerization Mechanisms on Lewis Acidic Beta Zeolites Using Isotropic Tracer Studies and 1H NMR

Biofuels synthesized from biomass sources are becoming necessary for sustainable production due to their significantly lower net CO2 production than fuels synthesized from fossil-based carbon sources such as petroleum. Catalytic pathways for the primary biomass-to-biofuels reaction pathway include the isomerization of glucose to fructose, which can be catalyzed by either Lewis acids or bases. Isolated metal atoms and metal oxide particles on Beta zeolites serve as active sites that catalyze this reaction through a Lewis acid 1,2-intramolecular hydride shift or by a Lewis base proton transfer mechanism, respectively. The Lewis acid mechanism has proven to have higher fructose selectivity than the Lewis base mechanism. Determining the glucose-fructose isomerization mechanism provides critical information about the active site placement in catalysts prepared by different methods, making it an ideal test of quality control for new material syntheses. Using glucose reactants deuterated at the second carbon, catalytic reaction mechanisms could be determined by tracing the location of the deuterium atom in the sugar products using 1H NMR spectroscopy. Comparison of fructose product spectra with an unlabeled fructose standard was used to show that glucose isomerization to fructose followed the Lewis acidic pathway on the samples in this study. The outcomes of these isotopic labeling studies provide insight into the placement of Lewis acid metals in zeolite frameworks and help to further understand this important step in biomass conversion to biofuels

Ca & Sr dynamics in the Indogangetic plains: different sources and mobilization processes in northwestern India

The leachable fraction of the sediments from the Thar Desert fringe and the adjacent Ganges alluvial plains, has been studied to determine the sources and the processes responsible for the mobilization of Ca and Sr using Sr isotopes and Ca/Sr ratios. In the desert the leachable fraction of the soil/sediments is probably derived from mixing of old marine carbonates, microfossils with the sea-spray of the Arabian Sea and rainwater. Aeolian reworking of soil carbonates of this mixed origin could have provided the carbonate found at the desert fringe. The sub-humid zone of the Gangetic plains, just outside the desert fringe, has relatively higher 87Sr/86Sr ratios with lower Ca/Sr ratios, indicating silicate weathering as the major contributor of leachable fraction. The spatial geochemical differences could also be related to the ineffectiveness of dust transport and accumulation processes in the humid Ganga plain. The 87Sr/86Sr ratio of the present-day dust leachate from the polluted city of Delhi indicates that its Sr source is petroleum burnt residues

Is river Ghaggar, Saraswati? Geochemical constraints

The identity of the river along which the famous Harappan Civilization developed and the causes of the demise of this culture are topics of considerable debate. Many of the Harappan sites are located along the ephemeral Ghaggar river within the Thar Desert in the northwestern India and adjacent Pakistan. The Ghaggar was also thought to be the mythical river Saraswati, which was described as glacial-fed river. Sr and Nd isotopic composition of the Ghaggar alluvium as well as Thar Desert sediments suggests a Sub-Himalayan sediment source, with no contribution from the glaciated regions. The development of extensive Harappan Civilization all along the Ghaggar suggests a catchment with high monsoon rainfall. It is likely that with the changes in the monsoon scenario after 3500 BC could have gradually dried up the Ghaggar river and resulted in the migration and/or extinction of the Harappan Civilization on this river

Is Rhiver Ghaggar, Saraswati? Geochemical constraints

The identity of the river along which the famous Harappan Civilization developed and the causes of the demise of this culture are topics of considerable debate. Many of the Harappan sites are located along the ephemeral Ghaggar river within the Thar Desert in the northwestern India and adjacent Pakistan. The Ghaggar was also thought to be the mythical river Saraswati, which was described as glacial-fed river. Sr and Nd isotopic composition of the Ghaggar alluvium as well as Thar Desert sediments suggests a Sub-Himalayan sediment source, with no contribution from the glaciated regions. The development of extensive Harappan Civilization all along the Ghaggar suggests a catchment with high monsoon rainfall. It is likely that with the changes in the monsoon scenario after 3500 BC could have gradually dried up the Ghaggar river and resulted in the migration and/or extinction of the Harappan Civilization on this rive

Initiating a Research-Focused Academic Career in Chemical Engineering: Perspectives from Faculty at Different Career Stages

Each fall, eager young researchers participate in the Meet the Faculty Candidates poster session at the AIChE Annual Meeting, and many more apply to tenure‐track faculty openings at academic institutions across the United States and throughout the world. These individuals embark on this journey with the eventual goal of becoming full professors. The process of initiating an academic career and developing a successful independent research program is an arduous journey that involves multiple stages. These stages include being hired into a faculty position, building an independent research program that involves recruiting students and can include constructing a laboratory, identifying research areas and specific problems to investigate, and establishing oneself as a scientific leader of a particular subject matter area within a broader community. Faculty candidates commonly seek advice from mentors or peers who have recently navigated the faculty interview and hiring processes to successfully obtain an academic position. Additionally, they often review the wealth of resources that are available on the Internet and in print. However, it can be daunting to sieve through this collective knowledge base to identify relevant information, as it invariably contains conflicting viewpoints and advice that may be subjective, generic to any research‐focused faculty position, or highly field specific

Initiating a Research-Focused Academic Career in Chemical Engineering: Perspectives from Faculty at Different Career Stages

Each fall, eager young researchers participate in the Meet the Faculty Candidates poster session at the AIChE Annual Meeting, and many more apply to tenure‐track faculty openings at academic institutions across the United States and throughout the world. These individuals embark on this journey with the eventual goal of becoming full professors. The process of initiating an academic career and developing a successful independent research program is an arduous journey that involves multiple stages. These stages include being hired into a faculty position, building an independent research program that involves recruiting students and can include constructing a laboratory, identifying research areas and specific problems to investigate, and establishing oneself as a scientific leader of a particular subject matter area within a broader community. Faculty candidates commonly seek advice from mentors or peers who have recently navigated the faculty interview and hiring processes to successfully obtain an academic position. Additionally, they often review the wealth of resources that are available on the Internet and in print. However, it can be daunting to sieve through this collective knowledge base to identify relevant information, as it invariably contains conflicting viewpoints and advice that may be subjective, generic to any research‐focused faculty position, or highly field specific

A Two-Stage Image Frame Extraction Model -ISLKE for Live Gesture Analysis on Indian Sign Language

The new industry revolution focused on Smart and interconnected technologies along with the Robotics and Artificial Intelligence, Machine Learning, Data analytics etc. on the real time data to produce the value-added products. The ways the goods are being produced are aligned with the people’s life style which is witnessed in terms of wearable smart devices, digital assistants, self-driving cars etc. Over the last few years, an evident capturing of the true potential of Industry 4.0 in health service domain is also observed. In the same context, Sign Language Recognition- a breakthrough in the live video processing domain, helps the deaf and mute communities grab the attention of many researchers. From the research insights, it is clearly evident that precise extraction and interpretation of the gesture data along with an addressal of the prevailing limitations is a crucial task. This has driven the work to come out with a unique keyframe extraction model focusing on the preciseness of the interpretation. The proposed model ISLKE deals with a clustering-based two stage keyframe extraction process. It has experimented on daily usage vocabulary of Indian Sign Language (ISL) and attained an average accuracy of 96% in comparison to the ground-truth facts. It is also observed that with the two-stage approach, filtering of uninformative frames has reduced complexity and computational efforts. These key leads, help in the further development of commercial communication applications in order to reach the speech and hearing disorder communities