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Laser-induced plasma electron number density:Stark broadening method versus the Saha-Boltzmann equation

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Plasma Science and Technology 2017年第2期19卷 43-51页

作者： arnab.sarkar Manjeet SINGH Fuel Chemistry Division Bhabha Atomic Research CentreMumbai 400 085India

We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd：YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation （SBE）. Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.

关键词： plasma parameter laser induced plasma plasma electron density Saha-Boltzmannmethod Stark broadening method

Time-resolved evaluation of uranium plasma in different atmospheres by laser-induced breakdown spectroscopy

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Plasma Science and Technology 2018年第12期20卷 65-74页

作者： Manjeet SINGH arnab.sarkar Fuel Chemistry Division Bhabha Atomic Research CentreMumbai 400 085India Homi Bhabha National Institute AnushaktinagarMumbai 400 094India

This work reports spectroscopic studies of uranium containing plasma generated in air and argon environments. The 532 nm Q-switched Nd：YAG laser generates the optical breakdown plasma, which was recorded by a spectrometer and an intensified charge coupled device having a resolution of 25 pm. Neutral and ionized uranium lines in the wavelength range of 385.8-391.9 nm indicate significant width and shift variations during the first few microseconds. Electron temperature and density of the plasma are determined using the Boltzmann plot and the Saha-Boltzmann equation at various time delay. The study reveals the power law decay pattern of electron temperature and density, which changes to exponential decay pattern if large gate- width is used to acquire the signal, due to an averaging effect.

关键词： uranium laser induced plasma plasma parameter temporal evaluation electron temperature electron density LIBS

A Hybrid Offline-Online Approach to Adaptive Downlink Resource Allocation Over LTE

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IEEE/CAA Journal of Automatica Sinica 2019年第3期6卷 766-777页

作者： Satish Kumar Rajesh Devaraj arnab.sarkar IEEE the Department of Computer Science and Engineering IIT Guwahati

Radio resource management mechanisms in current and future wireless networks is expected to face an enormous challenge due to the ever increasing demand for bandwidth and latency sensitive applications on mobile devices. This is because an optimal resource allocation scheme which attempts to multiplex the available bandwidth in order to maximize Quality of service(QoS), will pose an exponential computational burden at eNodeB. In order to minimize such computational overhead, this work proposes a hybrid offline-online resource allocation strategy which effectively allocates all the available resources among flows such that their QoS requirements are satisfied. The flows are firstly classified into priority buckets based on real-time criticality factors. During the offline phase, the scheduler attempts to maintain the system load within a pre-specified safe threshold value by selecting an appropriate number of buckets. This offline selection procedure makes use of supervisory control theory of discrete event systems to synthesize an offline scheduler. Next, we have devised an online resource allocation strategy which runs on top of the offline policy and attempts to minimize the impact of the inherent variability in wireless networks. Simulation results show that the proposed scheduling framework is able to provide satisfactory QoS to all end users in most practical scenarios.

关键词： Discrete event systems (DES) hybrid scheduling long term evolution (LTE) quality of service (QoS) radio resource management supervisory control

Preliminary Variations in Physiological Modules When <i>sub</i>1<i>A</i>QTL Is under Soil-Moisture Deficit Stress

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American Journal of Plant Sciences 2018年第4期9卷 732-744页

作者： Indraneel Saha arnab Kumar De Arijit Ghosh Bipul sarkar Narottam Dey Malay Kumar Adak Department of Botany University of Kalyani Kalyani India Department of Biotechnology Visva-Bharati University Santiniketan India

The present investigation embodies with some distinct physiological responses of rice seedlings bearing sub1A allele when cultured under soil moisture deficit condition. In order to estimate the extent of variation of sub1A allele in cv. Swarna Sub1, few specific responses were recorded. Ongoing days (2, 4 and 8) of water stress, rice seedlings were mostly concerned with regulation of root growth through 1.24%, 4.10% and 8.96% as compared to control. When relative growth rate (RGR) of the biomass was considered, it recorded a significant down regulation maximum by 27.27% over non-stressed plants. The light absorbing capacity of foliages in terms of leaf mass ratio (15.62%) and specific leaf weight (8.45%) was also curtailed under stress contiguously with total dry matter accumulation. For light harnessing mechanism, the contributing pigments were most significantly (p ≤ 0.05) affected with maximum variation for chlorophyll (31.29%), lycopene (79.31%) and carotenoids (55.31%) over control. NAR was strikingly differed by 32.72% under water stress in average. To support the water stress related depletion of moisture tension, plants recorded RWC with a ranges of 6.62% to 21.57% under stress than control. In balance of cellular dehydration rice seedlings were recorded 6.72% loss of proline, but up-regulated the release of free amino acids by 1.35 fold. In expression of generic potential for sub1A allele, the growth inhibition even under water deficit was evident from carbohydrate depletion by 10.93%, 11.42% and 24.35% through days of treatments. This was supported by depletion of apoplastic and cellular invertase activities by 90.90% and 72.91%. The possibility for sub1A in tolerance of deficit water status in rice culture has been discussed in more details.

关键词： sub1A Rice Water Deficit Growth Metabolism