Browsing by Author "Kumar, Haldhar"

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    Enhancing the electrochemical performance of TiO2 based material using microwave air plasma treatment with an ECR cavity
    (Frontiers Media S.A., 2022-11-24T00:00:00) Swaroop, Ram; Rani, Pinki; Jamwal, Gaurav; Sabavath, Gopikishan; Kumar, Haldhar; Jewariya, Yogesh
    The microwave-based plasma treatment facility at the Central University of Punjab Bathinda (CUPB) based on 2.45�GHz has been used to investigate the impact on the electrochemical performance of TiO2. This was accomplished by treating a number of pellets of TiO2 sample material with microwave plasma at an input power of 80�W. The palette is subjected to microwave plasma treatment at 30-, 60-, 80-, and 100-s intervals. Many such characterization methods, including UV-visible spectroscopy, FTIR, XRD, and FESEM, have been applied to the study of the impact of plasma treatment on other physical and chemical properties in the context of untreated pellets. In the 80-s plasma treatment, the FTIR study showed that the (O-Ti-O) vibration band at 500�900�cm?1 was wider than other bands. The UV results showed that an 80-s plasma treatment decreased the sample�s band gap by 37% and increased the amount of disordered, amorphous material in the sample that had not been treated. XRD studies show that a sample that was treated with plasma for 80�s has low crystallinity and a high disorder (amorphous) factor. The Nyquist plot showed that the electrochemical charge transfer resistance drops from 7 (not treated) to 4 after 80�s of plasma treatment. In a study of electrochemical performance, a sample that was treated with plasma for 80�s has a capacitance that is 35% higher than a sample that was not treated. Copyright � 2022 Swaroop, Rani, Jamwal, Sabavath, Kumar and Jewariya.
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    Luminescence chronology of Late Quaternary palaeo-lake deposits from the Upper Alaknanda Basin, Uttarakhand, India: Implication to palaeoclimate and depositional settings
    (Elsevier Ltd, 2022-01-06T00:00:00) Pattanaik, Jitendra Kumar; Singh, Atul; Kumar, Haldhar; Singh Shah, Sunil; Semwal, Prabhat; Sujith Naik, M.; Nayak, Kalyani; Jaiswal, Manoj K.; Banerjee, Argha; Nainwal, Harish Chandra; Shankar, Ramachandran
    Lakes downstream of the glaciers receive glacial meltwater and sediment supply resulting in formation of thick succession of lacustrine deposits. In this work, we have identified one such palaeo-lake deposit in the Upper Alaknanda Basin, close to Badrinath town. The sediments are of lacustrine origin; however the continuity is broken by intermittent fluvial deposits, which indicate changes in the depositional environment. We used Optically Stimulated Luminescence (OSL) dating to develop a robust chronology of the palaeo-lake deposit. Grain size analyses of sediments were carried out to understand the depositional environment, and morphometric analysis of the valley was conducted to obtained clues about the neotectonic activities in the region. The OSL ages show that the deposition of the lake sediments occurred between 21.6 � 4.7 ka to 10.5 � 1.4 ka. Two phases of paleo-lake deposit and subsequent outburst is established from the OSL age, grain size distribution and on the basis of field observations. The high sedimentation rate in the upper part of the deposit indicates an increase in the monsoonal rainfall and glacial retreat post Younger Dryas event. The colder periods are represented by varves and rhythmites, while the warmer periods are represented by thick laminated sand. This study indicates that the glaciers in the Upper Alakanada Basin responded to the fluctuations in the palaeo-climate. � 2022 Elsevier Ltd