Abstract
We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible ...and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar
1+
line emissions at 472.69 nm (3p
4
4s
2
P
3/2
–3p
4
4p
2
D
3/2
), 473.59 nm (3p
4
4s
4
P
5/2
–3p
4
4p
4
P
3/2
), 476.49 nm (3p
4
4s
2
P
1/2
–3p
4
4p
2
P
3/2
), 480.60 nm (3p
4
4s
4
P
5/2
–3p
4
4p
4
P
5/2
) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar
13+
line emission at 18.79 nm (2s
2
2p
2
P
3/2
–2s2p
2
2
P
3/2
) and Ar
14+
line emission at 22.11 nm (2s
2
1
S
0
–2s2p
1
P
1
). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar
1+
emission and the line intensity ratio of Ar
13+
and Ar
14+
ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m
2
/s and ~ 0.3 m
2
/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.
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We report a precision measurement of the parity-violating asymmetry APV in the elastic scattering of longitudinally polarized electrons from 208Pb. We measure APV= 550 ± 16 (stat) ±8 (syst) parts per ...billion, leading to an extraction of the neutral weak form factor FW(Q2= 0.00616 GeV2) = 0.368 ± 0.013. Combined with our previous measurement, the extracted neutron skin thickness is Rn-Rp= 0.283 ± 0.071 fm. The result also yields the first significant direct measurement of the interior weak density of 208Pb: ρ$^0_W$ = -0.0796 ± 0.0036(exp) ± 0.0013(theo) fm-3 leading to the interior baryon density ρ$^0_b$ = 0.1480 ± 0.0036(exp) ± 0.0013(theo) fm-3. Finally, the measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
The efficient (site-specific) management of soil nutrients is possible by understanding the spatial variability in distribution of phyto-available nutrients (here after called available nutrients) ...and identifying the soil management zones (MZs) of agricultural landscapes. There is need for delineating soil MZs of agricultural landscapes of the world for efficient management of soil nutrients in order to obtain sustainability in crop yield. The present study was, therefore, undertaken to understand the spatial distribution pattern of available micronutrients (zinc (Zn), boron (B), iron (Fe), manganese (Mn) and copper (Cu)), available sulphur (S), and soil properties (soil acidity (pH), electrical conductivity (EC) and organic carbon (SOC) content) in soils of intensively cultivated Indo-Gangetic Plain (IGP) of India and to delineate soil MZs for efficient management of soil nutrients. Totally, 55101 soil samples from 0-15 cm depth were obtained from 167 districts of IGP during 2014 to 2017 and were analysed for different soil parameters. Soil pH, EC and SOC content varied from 4.44 to 9.80, 0.02 to 2.13 dS m.sup.-1 and 0.10 to 1.99%, respectively. The concentration of available Zn, B, Fe, Mn, Cu and S varied from 0.01 to 3.27, 0.01 to 3.51, 0.19 to 55.7, 0.05 to 49.0, 0.01 to 5.29 and 1.01 to 108 mg kg.sup.-1, respectively. Geostatistical analysis resulted in varied distribution pattern of studied soil parameters with moderate to strong spatial dependence. The extent (% area) of nutrient deficiencies in IGP followed the order: S > Zn > B > Mn > Cu > Fe. Principal component analysis and fuzzy c-means clustering produced six distinctly different soil MZs of IGP for implementation of zone-specific soil nutrient management strategies for attaining sustainability in crop yield. The developed MZ maps could also be utilized for prioritization and rationalization of nutrients supply in IGP of India.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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► An easy route to introduce plenty of defects in ZnO. ► Evidences for silver is an efficient stabilizer of intrinsic defects in ZnO at high temperatures. ► Defect controlled ...electronic properties of unmodified and Ag modified ZnO.
The stabilization of defects in ZnO at high temperatures has been investigated. The properties of unmodified and modified ZnO nanoparticles (NPs) with 2at.% of Ag prepared by microwave assisted combustion method, have been systematically studied using X-ray diffraction (XRD), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and photocatalytic activity measurements. Though the XRD data shows a marginal shift in the ZnO peak position upon Ag addition, the amount of shift does not change with annealing temperatures. The PL data reveals that the defect mediated visible emission intensity of unmodified ZnO NPs increases with increase in the annealing temperature, whereas it remains almost unchanged in Ag–ZnO. This study clearly establishes that silver is an efficient stabilizer of intrinsic defects in ZnO at high temperatures. This is further supported by the core and valence band XPS spectra.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
A Ka-Band ultra-fast, ultra-wide band Frequency Modulated Continuous Wave (FMCW) reflectometer to measure the plasma density profile has been designed and developed at Institute for Plasma ...Research (IPR). We present here the need for ultra-fast and ultra-wide frequency of operation and estimate expected beat frequencies for the instrument. Three distinct corrections are made to the obtained frequencies. Firstly, inherent non-linearity of the frequency source is removed by shifting non-linearity to the tuning voltage of the hyper-abrupt varactor tuned oscillator and then correcting mismatch of the absolute values of frequency by introducing a delay line to account for the
difference in length between active and reference paths
for producing the beat frequencies. Using code developed based on the short time Fourier transform we extract the beat frequency to measure various known distances and verify with our beat frequency estimations and also show that range resolution obtained is very close to the theoretical one obtained.
In this paper, the dynamic model of a wheeled inverted pendulum (e.g., Segway, Quasimoro, and Joe) is analyzed from a controllability and feedback linearizability point of view. First, a dynamic ...model of this underactuated system is derived with respect to the wheel motor torques as inputs while taking the nonholonomic no-slip constraints into considerations. This model is compared with the previous models derived for similar systems. The strong accessibility condition is checked and the maximum relative degree of the system is found. Based on this result, a partial feedback linearization of the system is obtained and the internal dynamics equations are isolated. The resulting equations are then used to design two novel controllers. The first one is a two-level velocity controller for tracking vehicle orientation and heading speed set-points, while controlling the vehicle pitch (pendulum angle from the vertical) within a specified range. The second controller is also a two-level controller which stabilizes the vehicle's position to the desired point, while again keeping the pitch bounded between specified limits. Simulation results are provided to show the efficacy of the controllers using realistic data.
In India, five states, viz., Uttar Pradesh, Maharashtra, Karnataka, Tamil Nadu and Bihar, contribute about 84.64% sugarcane production of the country and occupy about 82.46% cropped area. The mean ...productivity of these states is also higher as compared to remaining states. However, the yield gap up to 33.0 t ha
−1
prevails among these states. The performance of technologies in different states also varies depending on constrains and potentials of the region. Thus, the objectives of our study were (1) to assess the yield gap between attainable yield and farmers yield in potential sugarcane-growing states of the country and (2) to determine the long-term relationship between improved technologies and sugarcane yields at various levels. Yield gap analysis revealed that Uttar Pradesh recorded the highest positive correlation between period and sugarcane yield (
R
2
= 0.917/
r
= 0.96) and showed that technological advancements caused linear increase in sugarcane yield. Out of eight technologies, five technologies, i.e. improved variety, pit method of planting, intercropping, drip irrigation and ratoon management, enhanced sugarcane yield by > 20% and could be placed as top rankers. In Maharashtra, improved variety, ratoon management, intercropping and integrated nutrient management were recorded as top rankers and improved sugarcane yields in the range of 20.44–31.29%, individually. In Karnataka, drip irrigation, intercropping, ratoon management and improved varieties increased > 20% sugarcane yield as compared to state average sugarcane yield. However, wide row spacing and INM could increase yield level in the range of 15.17% and 17.65%, respectively. In Tamil Nadu, the various technologies could increase about 4.35–35.87% higher sugarcane yields as compared to farmers practice. Pit method planting showed the highest improvement in yield (35.87%). Improved varieties, integrated weed management, intercropping and ratoon management showed positive effect in the range of 13.28–19.0% as compared to mean of technologies demonstrated in five states. In Bihar, the improved variety contributed 40.2% yield increase as compared to state average yield (59.25 t ha
−1
). Ratoon management (35.14%) and intercropping in sugarcane (31.76%) could also be ranked in the top category in increasing sugarcane yields. Thus, it could be recorded that improved variety in Maharashtra and Bihar, pit/trench method of planting in Uttar Pradesh and Tamil Nadu drip irrigation and ratoon management in Karnataka are the major technologies contributing in sugarcane yield. Therefore, these technologies need to be promoted in the potential sugarcane-growing states to improve the national average.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Using data from 33 models from the CMIP5 historical and AMIP5 simulations, we have carried out a systematic analysis of biases in total precipitation and its convective and large-scale components ...over the south Asian region. We have used 23 years (1983-2005) of data, and have computed model biases with respect to the PERSIANN-CDR precipitation (with convective/large-scale ratio derived from TRMM 3A12). A clustering algorithm was applied on the total, convective, and large-scale precipitation biases seen in CMIP5 models to group them based on the degree of similarity in the global bias patterns. Subsequently, AMIP5 models were analyzed to conclude if the biases were primarily due to the atmospheric component or due to the oceanic component of individual models. Our analysis shows that the set of individual models falling in a given group is somewhat sensitive to the variable (total/convective/large-scale precipitation) used for clustering. Over the south Asian region, some of the convective and large-scale precipitation biases are common across groups, emphasizing that although on a global scale the bias patterns may be sufficiently different to cluster the models into different groups, regionally, it may not be true. In general, models tend to overestimate the convective component and underestimate the large-scale component over the south Asian region, although with spatially varying magnitudes depending on the model group. We find that the convective precipitation biases are largely governed by the closure and trigger assumptions used in the convection parameterization schemes used in these models, and to a lesser extent on details of the individual cloud models. Using two different methods: (i) clustering, (ii) comparing the bias patterns of models from CMIP5 with their AMIP5 counterparts, we find that, in general, the atmospheric component (and not the oceanic component through biases in SSTs and atmosphere-ocean feedbacks) plays a major role in deciding the convective and large-scale precipitation biases. However, the oceanic component has been found important for one of the convective groups in deciding the convective precipitation biases (over the maritime continent).
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