Natural kaolin was refluxed with sulphuric acid of different concentrations 1
M, 3
M, 5
M and 10
M at 110
°C for 4
h followed by calcination at 500
°C for 2
h. The physico-chemical characteristics of ...acid-leached kaolinite clay were studied by XRF, XRD, FTIR, TGA, DTA, SEM and N
2 adsorption techniques. XRF and FTIR studies indicate that acid treatment under reflux conditions leads to the removal of the octahedral Al
3+ cations along with other impurities. XRD of 5
M and 10
M treated kaolin shows that treatment with high concentrated acid provoked an amorphization resulting in the formation of an amorphous silica type phase. Leaching of Al
3+ ions increased progressively with severity of the acid treatment. The acid treatment increased the Si/Al ratio from 0.65 to 8.09, surface area from 23
m
2/g to 143
m
2/g and pore volume from 0.361
cc/g to 1.18
cc/g as the acid concentration was increased to 10
M. Solids thus obtained by acid treatments can be used as promising adsorbents and catalyst supports.
The present rate of economic growth is unsustainable without saving of fossil energy like crude oil, natural gas or coal. Thus mankind has to rely on the alternate/renewable energy sources like ...biomass, hydropower, geothermal energy, wind energy, solar energy, nuclear energy, etc. On the other hand, suitable waste management strategy is another important aspect of sustainable development. The growth of welfare levels in modern society during the past decades has brought about a huge increase in the production of all kinds of commodities, which indirectly generate waste. Plastics have been one of the materials with the fastest growth because of their wide range of applications due to versatility and relatively low cost. Since the duration of life of plastic products is relatively small, there is a vast plastics waste stream that reaches each year to the final recipients creating a serious environmental problem. Again, because disposal of post consumer plastics is increasingly being constrained by legislation and escalating costs, there is considerable demand for alternatives to disposal or land filling. Advanced research in the field of green chemistry could yield biodegradable/green polymers but is too limited at this point of time to substitute the non-biodegradable plastics in different applications. Once standards are developed for degradable plastics they can be used to evaluate the specific formulations of materials which will find best application in this state as regards their performance and use characteristics. Among the alternatives available are source reduction, reuse, recycling, and recovery of the inherent energy value through waste-to-energy incineration and processed fuel applications. Production of liquid fuel would be a better alternative as the calorific value of the plastics is comparable to that of fuels, around 40Â MJ/kg. Each of these options potentially reduces waste and conserves natural resources. Plastics recycling, continues to progress with a wide range of old and new technologies. Many research projects have been undertaken on chemical recycling of waste plastics to fuel and monomer. This is also reflected by a number of pilot, demonstration, and commercial plants processing various types of plastic wastes in Germany, Japan, USA, India, and elsewhere. Further investigations are required to enhance the generation of value added products (fuel) with low investments without affecting the environment. The paper reviews the available literature in this field of active research and identifies the gaps that need further attention.
The reactor antineutrinos are used for the precise measurement of oscillation parameters in the 3-neutrino model, and also used to investigate active-sterile neutrino mixing sensitivity in the
3
+
1
...neutrino framework. In the present work, we study the feasibility of sterile neutrino search with the indian scintillator matrix for reactor anti-neutrino (ISMRAN) experimental set-up using electron antineutrinos (
ν
¯
e
) produced from reactor as a source. The so-called
3
+
1
scenario is considered for active-sterile neutrino mixing, which leads to projected exclusion curves in the sterile neutrino mass and mixing angle plane. The analysis is performed considering both the reactor and detector related parameters. It is found that, the ISMRAN set-up can observe the active-sterile neutrino mixing sensitivity for
sin
2
2
θ
14
≥
0.064
and
Δ
m
41
2
=
1.0
eV
2
at
90
%
confidence level for an exposure of 1 ton-year by using neutrinos produced from the DHRUVA reactor with thermal power of
100
MW
th
. It is also observed that, there is a significant improvement of the active-sterile neutrino mixing parameter
sin
2
2
θ
14
to
∼
0.03 at the same
Δ
m
41
2
by putting the ISMRAN detector set-up at a distance of 20 m from the compact proto-type fast breeder reactor facility with thermal power of 1250
MW
th
.
In the present study, a total of 53 promising salt-tolerant genotypes were tested across 18 salt-affected diverse locations for three years. An attempt was made to identify ideal test locations and ...mega-environments using GGE biplot analysis. The CSSRI sodic environment was the most discriminating location in individual years as well as over the years and could be used to screen out unstable and salt-sensitive genotypes. Genotypes CSR36, CSR-2K-219, and CSR-2K-262 were found ideal across years. Overall, Genotypes CSR-2K-219, CSR-2K-262, and CSR-2K-242 were found superior and stable among all genotypes with higher mean yields. Different sets of genotypes emerged as winners in saline soils but not in sodic soils; however, Genotype CSR-2K-262 was the only genotype that was best under both saline and alkaline environments over the years. The lack of repeatable associations among locations and repeatable mega-environment groupings indicated the complexity of soil salinity. Hence, a multi-location and multi-year evaluation is indispensable for evaluating the test sites as well as identifying genotypes with consistently specific and wider adaptation to particular agro-climatic zones. The genotypes identified in the present study could be used for commercial cultivation across edaphically challenged areas for sustainable production.
A novel thermal plasma in-flight technique has been adopted to synthesize nanocrystalline ZnO and carbon doped nanocrystalline ZnO matrix. Transmission electron microscopy (TEM) studies on these ...samples show the average particle sizes to be around 32nm for ZnO and for carbon doped ZnO. An enhancement of saturation magnetization in nanosized carbon doped ZnO matrix by a factor of 3.8 has been found in comparison to ZnO nanoparticles at room temperature. Raman measurement clearly indicates the presence of Zn–C complexes surrounded by ZnO matrix in carbon doped ZnO. This indicates that the ferromagnetic signature in carbon doped ZnO arises from the creation of defects or the development of oxy-carbon clusters, in the carbon doped ZnO system. Theoretical studies based on density functional theory also support the experimental analyses.
► Synthesis of nanocrystalline ZnO and carbon doped ZnO matrix by inflight thermal plasma reactor. ► Enhancement of ferromagnetism in nanosized carbon doped ZnO in comparison to ZnO nanoparticles. ► Raman measurement indicates the presence of Zn–C complexes surrounded by ZnO matrix. ► Ferromagnetic signature in carbon doped ZnO arises from the development of oxy-carbon clusters. ► DFT supports experimental evidence of ferromagnetism in C doped ZnO nanoparticles.
This paper reports the effect of sintering temperature on ferroelectric properties of GdMnO3 (GMO) bulk ceramics at room temperature prepared by the conventional solid state reaction route following ...slow step sintering schedule. Ferroelectric hysteresis loop as well as sharp dielectric anomaly in pure (99.999%) GMO sintered ceramics has been clearly observed. Samples sintered at 1350°C become orthorhombic with Pbnm space group and showed frequency independent sharp dielectric anomalies at 373K and a square type of novel ferroelectric hysteresis loop was observed at room temperature. Interestingly, dielectric anomalies and ferroelectric behavior were observed to be dependent upon sintering temperature of GdMnO3. Room temperature dielectric constant (εr) value at different frequencies is observed to be abnormally high. The magnetic field and temperature dependent magnetization show antiferromagnetic behavior at 40K for both 1350°C and 1700°C sintered GMO. Present findings showed the possibility of application of GdMnO3 at room temperature as multifunctional materials.
• Preparation of single-phasic polycrystalline GdMnO3 sample by the solid state sintering route.• Observation of square type P–E hysteresis loop with higher saturation and remnant polarization.• Observation of antiferromagnetic behavior at 40K in polycrystalline GdMnO3.• Possibility of room temperature application of GdMnO3 as multifunctional material.
We observed that ZnO bulk ceramics prepared by solid state reaction route at 1300 degree C exhibited unexpected room temperature ferromagnetic (RTFM) property. In the absence of any magnetic impurity ...the cause of room temperature ferromagnetic signal in the undoped system is certainly attributed to various kinds of native defects such as oxygen vacancies (V sub(O)) or zinc interstitials (I sub(Zn)) and their clusters created inside the bulk ceramics during heating by slow step sintering schedule (SSSS). The micro-Raman investigation and X-ray photoelectron spectroscopy studies on the ZnO sample sintered at high temperature confirm the presence of such lattice defects.
In this work, we present an analysis of the sensitivity to the active-sterile neutrino mixing with the Indian Scintillator Matrix for Reactor Anti-Neutrino (ISMRAN) experimental setup at very short ...baseline. The 3 ( active ) + 1 (sterile) neutrino oscillation model is considered to study the sensitivity of the active-sterile neutrino in the mass splitting and mixing angle plane. In this article, we have considered the measurement of electron antineutrino induced events employing a single detector which can be placed either at a single position or moved between a near and far positions from the given reactor core. Results extracted in the later case are independent of the theoretical prediction of the reactor anti-neutrino spectrum and detector related systematic uncertainties. Our analysis shows that the results obtained from the measurement carried out at combination of the near and far detector positions are improved significantly at higher Δm412 compared to the ones obtained with the measurement at a single detector position only. It is found that the best possible combination of near and far detector positions from a 100 MWth power DHRUVA research reactor core are 7 m and 9 m, respectively, for which ISMRAN setup can exclude in the range 1.4 eV2 ≤ Δ m412 ≤ 4.0 eV2 of reactor antineutrino anomaly region along with the present best-fit point of active-sterile neutrino oscillation parameters. At those combinations of detector positions, the ISMRAN setup can observe the active sterile neutrino oscillation with a 95% confidence level provided that sin22θ14 ≥ 0.09 at Δm412 = 1 eV2 for an exposure of 1 ton-yr. The active-sterile neutrino mixing sensitivity can be improved by about 22% at the same exposure by placing the detector at near and far distances of 15 m and 17 m, respectively, from the compact proto-type fast breeder reactor (PFBR) facility which has a higher thermal power of 1250 MWth.
Abstract
The iron impregnated fungal bio-filter (IIFB) discs of luffa sponge containing
Phanerochaete chrysosporium
mycelia have been used for the removal of As(III) from water. Two different forms ...of same biomass viz. free fungal biomass (FFB) and modified free fungal biomass (chemically modified and iron impregnated; CFB and IIFB) have been simultaneously investigated to compare the performance of immobilization, chemo-tailoring and iron impregnation for remediation of As(III). IIFB showed highest uptake capacity and percentage removal of As(III), 1.32 mg/g and 92.4% respectively among FFB, CFB and IIFB. Further, the application of RSM and ANN-GA based mathematical model showed a substantial increase in removal i.e. 99.2% of As(III) was filtered out from water at optimised conditions i.e. biomass dose 0.72 g/L, pH 7.31, temperature 42 °C, and initial As(III) concentration 1.1 mg/L. Isotherm, kinetic and thermodynamic studies proved that the process followed monolayer sorption pattern in spontaneous and endothermic way through pseudo-second order kinetic pathway. Continuous mode of As(III) removal in IIFB packed bed bioreactor, revealed increased removal of As(III) from 76.40 to 88.23% with increased column height from 5 to 25 cm whereas the removal decreased from 88.23 to 69.45% while increasing flow rate from 1.66 to 8.30 mL/min. Moreover, the IIFB discs was regenerated by using 10% NaOH as eluting agent and evaluated for As(III) removal for four sorption–desorption cycles, showing slight decrease of their efficiency by 1–2%. SEM–EDX, pHzpc, and FTIR analysis, revealed the involvement of hydroxyl and amino surface groups following a non-electrostatic legend exchange sorption mechanism during removal of As(III).
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